Age affects sleep microstructure more than sleep macrostructure.

PubMed

Schwarz, Johanna F A; Åkerstedt, Torbjörn; Lindberg, Eva; Gruber, Georg; Fischer, Håkan; Theorell-Haglöw, Jenny

2017-06-01

It is well known that the quantity and quality of physiological sleep changes across age. However, so far the effect of age on sleep microstructure has been mostly addressed in small samples. The current study examines the effect of age on several measures of sleep macro- and microstructure in 211 women (22-71 years old) of the 'Sleep and Health in Women' study for whom ambulatory polysomnography was registered. Older age was associated with significantly lower fast spindle (effect size f 2  = 0.32) and K-complex density (f 2  = 0.19) during N2 sleep, as well as slow-wave activity (log) in N3 sleep (f 2  = 0.21). Moreover, total sleep time (f 2  = 0.10), N3 sleep (min) (f 2  = 0.10), rapid eye movement sleep (min) (f 2  = 0.11) and sigma (log) (f 2  = 0.05) and slow-wave activity (log) during non-rapid eye movement sleep (f 2  = 0.09) were reduced, and N1 sleep (f 2  = 0.03) was increased in older age. No significant effects of age were observed on slow spindle density, rapid eye movement density and beta power (log) during non-rapid eye movement sleep. In conclusion, effect sizes indicate that traditional sleep stage scoring may underestimate age-related changes in sleep. © 2017 European Sleep Research Society.

ELECTRICAL STUDIES ON THE COMPOUND EYE OF LIGIA OCCIDENTALIS DANA (CRUSTACEA: ISOPODA)

PubMed Central

Ruck, Philip; Jahn, Theodore L.

1954-01-01

The ERG of the compound eye in freshly collected Ligia occidentalis, in response to high intensity light flashes of ⅛ second or longer duration, begins with a negative on-effect quickly followed by an early positive deflection, rapidly returns to the baseline during illumination, and ends with a positive off-effect. As the stimulus intensity is decreased the early positivity progressively decreases and the rapid return to the baseline is replaced by a slowing decline of the negative on-effect. Responses were recorded with one active electrode subcorneally situated in the illuminated eye, the reference electrode in the dark eye. The dark-adapted eye shows a facilitation of the amplitude and rates of rise and fall of the on-effect to a brief, high intensity light stimulus. This facilitation may persist for more than 2 minutes. Following light adaptation under conditions in which the human eye loses sensitivity by a factor of almost 40,000 the Ligia eye loses sensitivity by a factor of only 3. The flicker fusion frequency of the ERG may be as high as 120/second with a corneal illumination of 15,000 foot-candles. Bleeding an otherwise intact animal very rapidly results in a decline of amplitude, change of wave form, and loss of facilitation in the ERG. When the eye is deganglionated without bleeding the animal the isolated retina responds in the same manner as the intact eye. Histological examination of the Ligia receptor layer showed that each ommatidium contains three different retinula cell types, each of which may be responsible for a different aspect of the ERG. PMID:13174786

Sleep duration varies as a function of glutamate and GABA in rat pontine reticular formation.

PubMed

Watson, Christopher J; Lydic, Ralph; Baghdoyan, Helen A

2011-08-01

The oral part of the pontine reticular formation (PnO) is a component of the ascending reticular activating system and plays a role in the regulation of sleep and wakefulness. The PnO receives glutamatergic and GABAergic projections from many brain regions that regulate behavioral state. Indirect, pharmacological evidence has suggested that glutamatergic and GABAergic signaling within the PnO alters traits that characterize wakefulness and sleep. No previous studies have simultaneously measured endogenous glutamate and GABA from rat PnO in relation to sleep and wakefulness. The present study utilized in vivo microdialysis coupled on-line to capillary electrophoresis with laser-induced fluorescence to test the hypothesis that concentrations of glutamate and GABA in the PnO vary across the sleep/wake cycle. Concentrations of glutamate and GABA were significantly higher during wakefulness than during non-rapid eye movement sleep and rapid eye movement sleep. Regression analysis revealed that decreases in glutamate and GABA accounted for a significant portion of the variance in the duration of non-rapid eye movement sleep and rapid eye movement sleep episodes. These data provide novel support for the hypothesis that endogenous glutamate and GABA in the PnO contribute to the regulation of sleep duration. © 2011 The Authors. Journal of Neurochemistry © 2011 International Society for Neurochemistry.

Consciousness in waking and dreaming: the roles of neuronal oscillation and neuromodulation in determining similarities and differences.

PubMed

Kahn, D; Pace-Schott, E F; Hobson, J A

1997-05-01

State-dependent aspects of consciousness are explored with particular attention to waking and dreaming. First, those phenomenological differences between waking and dreaming that have been established through subjective reports are reviewed. These differences are robustly expressed in most aspects of consciousness including perception, attention, memory, emotion, orientation, and thought. Next, the roles of high frequency neuronal oscillation and neuromodulation are explored in waking and rapid eye movement sleep, the stage of sleep with which the most intense dreaming is associated. The high frequency neuronal oscillations serve similar functions in the wake and rapid eye movement states sleep but neuromodulation is very different in the two states. The collective high frequency oscillatory activity gives coherence to spatially separate neurons but, because of the different neuromodulation, the binding of sensory input in the wake state is very different from the binding of internally perceived input during rapid eye movement sleep. An explanatory model is presented which states that neuromodulation, as well as input source and brain activation level differentiate states of the brain, while the self-organized collective neuronal oscillations unify consciousness via long range correlations.

Identification of cholinergic and non-cholinergic neurons in the pons expressing phosphorylated cyclic adenosine monophosphate response element-binding protein as a function of rapid eye movement sleep.

PubMed

Datta, S; Siwek, D F; Stack, E C

2009-09-29

Recent studies have shown that in the pedunculopontine tegmental nucleus (PPT), increased neuronal activity and kainate receptor-mediated activation of intracellular protein kinase A (PKA) are important physiological and molecular steps for the generation of rapid eye movement (REM) sleep. In the present study performed on rats, phosphorylated cyclic AMP response element-binding protein (pCREB) immunostaining was used as a marker for increased intracellular PKA activation and as a reflection of increased neuronal activity. To identify whether activated cells were either cholinergic or noncholinergic, the PPT and laterodorsal tegmental nucleus (LDT) cells were immunostained for choline acetyltransferase (ChAT) in combination with pCREB or c-Fos. The results demonstrated that during high rapid eye movement sleep (HR, approximately 27%), significantly higher numbers of cells expressed pCREB and c-Fos in the PPT, of which 95% of pCREB-expressing cells were ChAT-positive. With HR, the numbers of pCREB-positive cells were also significantly higher in the medial pontine reticular formation (mPRF), pontine reticular nucleus oral (PnO), and dorsal subcoeruleus nucleus (SubCD) but very few in the locus coeruleus (LC) and dorsal raphe nucleus (DRN). Conversely, with low rapid eye movement sleep (LR, approximately 2%), the numbers of pCREB expressing cells were very few in the PPT, mPRF, PnO, and SubCD but significantly higher in the LC and DRN. The results of regression analyses revealed significant positive relationships between the total percentages of REM sleep and numbers of ChAT+/pCREB+ (Rsqr=0.98) cells in the PPT and pCREB+ cells in the mPRF (Rsqr=0.88), PnO (Rsqr=0.87), and SubCD (Rsqr=0.84); whereas significantly negative relationships were associated with the pCREB+ cells in the LC (Rsqr=0.70) and DRN (Rsqr=0.60). These results provide evidence supporting the hypothesis that during REM sleep, the PPT cholinergic neurons are active, whereas the LC and DRN neurons are inactive. More importantly, the regression analysis indicated that pCREB activation in approximately 98% of PPT cholinergic neurons, was caused by REM sleep. Moreover the results indicate that during REM sleep, PPT intracellular PKA activation and a transcriptional cascade involving pCREB occur exclusively in the cholinergic neurons.

The coeruleus/subcoeruleus complex in idiopathic rapid eye movement sleep behaviour disorder.

PubMed

Ehrminger, Mickael; Latimier, Alice; Pyatigorskaya, Nadya; Garcia-Lorenzo, Daniel; Leu-Semenescu, Smaranda; Vidailhet, Marie; Lehericy, Stéphane; Arnulf, Isabelle

2016-04-01

Idiopathic rapid eye movement sleep behaviour disorder is characterized by nocturnal violence, increased muscle tone during rapid eye movement sleep and the lack of any other neurological disease. However, idiopathic rapid eye movement sleep behaviour disorder can precede parkinsonism and dementia by several years. Using 3 T magnetic resonance imaging and neuromelanin-sensitive sequences, we previously found that the signal intensity was reduced in the locus coeruleus/subcoeruleus area of patients with Parkinson's disease and rapid eye movement sleep behaviour disorder. Here, we studied the integrity of the locus coeruleus/subcoeruleus complex with neuromelanin-sensitive imaging in 21 patients with idiopathic rapid eye movement sleep behaviour disorder and compared the results with those from 21 age- and gender-matched healthy volunteers. All subjects underwent a clinical examination, motor, cognitive, autonomous, psychological, olfactory and colour vision tests, and rapid eye movement sleep characterization using video-polysomnography and 3 T magnetic resonance imaging. The patients more frequently had preclinical markers of alpha-synucleinopathies, including constipation, olfactory deficits, orthostatic hypotension, and subtle motor impairment. Using neuromelanin-sensitive imaging, reduced signal intensity was identified in the locus coeruleus/subcoeruleus complex of the patients with idiopathic rapid eye movement sleep behaviour. The mean sensitivity of the visual analyses of the signal performed by neuroradiologists who were blind to the clinical diagnoses was 82.5%, and the specificity was 81% for the identification of idiopathic rapid eye movement sleep behaviour. The results confirm that this complex is affected in idiopathic rapid eye movement sleep behaviour (to the same degree as it is affected in Parkinson's disease). Neuromelanin-sensitive imaging provides an early marker of non-dopaminergic alpha-synucleinopathy that can be detected on an individual basis. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of Macrophage Depletion on Sleep in Mice

PubMed Central

Ames, Conner; Boland, Erin; Szentirmai, Éva

2016-01-01

The reciprocal interaction between the immune system and sleep regulation has been widely acknowledged but the cellular mechanisms that underpin this interaction are not completely understood. In the present study, we investigated the role of macrophages in sleep loss- and cold exposure-induced sleep and body temperature responses. Macrophage apoptosis was induced in mice by systemic injection of clodronate-containing liposomes (CCL). We report that CCL treatment induced an immediate and transient increase in non-rapid-eye movement sleep (NREMS) and fever accompanied by decrease in rapid-eye movement sleep, motor activity and NREMS delta power. Chronically macrophage-depleted mice had attenuated NREMS rebound after sleep deprivation compared to normal mice. Cold-induced increase in wakefulness and decrease in NREMS, rapid-eye movement sleep and body temperature were significantly enhanced in macrophage-depleted mice indicating increased cold sensitivity. These findings provide further evidence for the reciprocal interaction among the immune system, sleep and metabolism, and identify macrophages as one of the key cellular elements in this interplay. PMID:27442442

Vasoactive intestinal polypeptide microinjections into the oral pontine tegmentum enhance rapid eye movement sleep in the rat.

PubMed

Bourgin, P; Lebrand, C; Escourrou, P; Gaultier, C; Franc, B; Hamon, M; Adrien, J

1997-03-01

Rapid eye movement sleep can be elicited in the rat by microinjection of the cholinergic agonist carbachol into the oral pontine reticular nucleus. Intracerebroventricular administration, during the light period, of vasoactive intestinal peptide enhances rapid eye movement sleep in several species. Since this peptide is co-localized with acetylcholine in many neurons in the central nervous system, it was assumed that the oral pontine tegmentum could also be one target for vasoactive intestinal peptide to induce rapid eye movement sleep. This hypothesis was tested by recording the sleep-wakefulness cycle in freely-moving rats injected with vasoactive intestinal peptide or its fragments (1-12 and 10-28) directly into the oral pontine reticular nucleus. when administered into the posterior part of this nucleus, vasoactive intestinal peptide at 1 and 10 ng (in 0.1 microliter of saline), but not its fragments, induced a 2-fold enhancement of rapid eye movement sleep during 4 h, at the expense of wakefulness. At the dose of 10 ng, a significant increase in rapid eye movement sleep persisted for up to 8 h. Moreover, when the peptide was injected into the centre of the positive zone, rapid eye movement sleep was enhanced during three to eight consecutive days. These data provide the first evidence that rapid eye movement sleep can be elicited at both short- and long-term by a single intracerebral microinjection of vasoactive intestinal peptide. Peptidergic mechanisms, possibly in association with cholinergic mechanisms, within the caudal part of the oral pontine reticular nucleus may play a critical role in the long-term regulation of rapid eye movement sleep in rats.

Modern optics in exceptionally preserved eyes of Early Cambrian arthropods from Australia

NASA Astrophysics Data System (ADS)

Lee, Michael S. Y.; Jago, James B.; García-Bellido, Diego C.; Edgecombe, Gregory D.; Gehling, James G.; Paterson, John R.

2011-06-01

Despite the status of the eye as an ``organ of extreme perfection'', theory suggests that complex eyes can evolve very rapidly. The fossil record has, until now, been inadequate in providing insight into the early evolution of eyes during the initial radiation of many animal groups known as the Cambrian explosion. This is surprising because Cambrian Burgess-Shale-type deposits are replete with exquisitely preserved animals, especially arthropods, that possess eyes. However, with the exception of biomineralized trilobite eyes, virtually nothing is known about the details of their optical design. Here we report exceptionally preserved fossil eyes from the Early Cambrian (~515 million years ago) Emu Bay Shale of South Australia, revealing that some of the earliest arthropods possessed highly advanced compound eyes, each with over 3,000 large ommatidial lenses and a specialized `bright zone'. These are the oldest non-biomineralized eyes known in such detail, with preservation quality exceeding that found in the Burgess Shale and Chengjiang deposits. Non-biomineralized eyes of similar complexity are otherwise unknown until about 85 million years later. The arrangement and size of the lenses indicate that these eyes belonged to an active predator that was capable of seeing in low light. The eyes are more complex than those known from contemporaneous trilobites and are as advanced as those of many living forms. They provide further evidence that the Cambrian explosion involved rapid innovation in fine-scale anatomy as well as gross morphology, and are consistent with the concept that the development of advanced vision helped to drive this great evolutionary event.

SOME PECULIARITIES IN INCLUSION AND DISTRIBUTION OF P$sup 32$ IN THE RABBIT EYE TISSUES (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Medvedovskaya, Ts.P.; Likharev, I.A.

1963-11-01

Data on levels of inclusion and correlations between the activities of P/ sup 32/ in the eye tissue of rabbits at different periods during two months after a single introduction of the isotope are presented. Experiments were staged on 21 rabbits (42 eyes). P/sup 32/ was introduced subcutaneously in a concentration of 250 C/kg. Distribution of the isotope was studied with the radiometric method. The content of the activity in the eye tissues was calculated in mu C and in percentage relation to the total activity of the eyeball The initial quantity of the isotope in the eye tissues inmore » percentage relation to the originally introduced amount was also calculated, as well as the content of activity in the tissues per 1 g of humid weight in mu C. In single subcutaneous introduction of P/sup 32/ it penetrates into all tissues of the rabbit eye. The eyeball recieves a total of 0.01%, of the activity introduced. On the first day the greatest concentration of activity is seen in the eye tissues with a rich vascular network, where intensive metabolic processes take place. The share of the crystalline lens in the included P/sup 32/ is negligible. Later on the named tissues rapidly eliminated P/sup 32/, whereas in the crystalline lens it is only on the 6th day that the maximum activity sets on. In a month and later about 50% of the activity preserved in the eye is concentrated in the crystalline lens. The most radiosensitive sections of the crystalline lens mainly accumulate P/sup 32/. (auth)« less

Overview of sleep: the neurologic processes of the sleep-wake cycle.

PubMed

Scammell, Thomas E

2015-05-01

Sleep problems are common in adults and should be treated to improve overall health and safety. To choose the best treatment for patients with sleep problems, clinicians should understand the sleep-wake cycle and the stages of rapid eye movement and non-rapid eye movement sleep as well as the neurologic pathways of sleep and wake systems. The sleep- and wake-promoting systems are mutually inhibitory, with the predominantly active system determining if a person is awake or asleep. The orexin system also plays an important role in the stabilization of the sleep-wake cycle. © Copyright 2015 Physicians Postgraduate Press, Inc.

Time course of EEG background activity level before spontaneous awakening in infants.

PubMed

Zampi, Chiara; Fagioli, Igino; Salzarulo, Piero

2002-12-01

This research aimed to investigate the time course of the cortical activity level preceding spontaneous awakening as a function of age and state. Two groups of infants (1-4 and 9-14 weeks of age) were continuously monitored by polygraphic recording and behavioural observation during the night. The electroencephalographic (EEG) activity recorded by the C3-O1 lead was analysed through an automatic analysis method which provides, for each 30-s epoch, a single measure, time domain based, of the EEG synchronization. The EEG parameter values were computed in the 6 min preceding each awakening out of non-rapid eye movement (NREM) sleep and out of rapid eye movement (REM) sleep. The EEG background activity level did not change in the minutes preceding awakening out of REM sleep. Awakening out of NREM sleep was preceded by a change of EEG activity level in the direction of higher activation with different time course according to the age. Both REM and NREM sleep results suggest that a high level of EEG activity is a prerequisite for the occurrence of a spontaneous awakening.

Tonic and phasic phenomena underlying eye movements during sleep in the cat

PubMed Central

Márquez-Ruiz, Javier; Escudero, Miguel

2008-01-01

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep–wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep–wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now. PMID:18499729

Tonic and phasic phenomena underlying eye movements during sleep in the cat.

PubMed

Márquez-Ruiz, Javier; Escudero, Miguel

2008-07-15

Mammalian sleep is not a homogenous state, and different variables have traditionally been used to distinguish different periods during sleep. Of these variables, eye movement is one of the most paradigmatic, and has been used to differentiate between the so-called rapid eye movement (REM) and non-REM (NREM) sleep periods. Despite this, eye movements during sleep are poorly understood, and the behaviour of the oculomotor system remains almost unknown. In the present work, we recorded binocular eye movements during the sleep-wake cycle of adult cats by the scleral search-coil technique. During alertness, eye movements consisted of conjugated saccades and eye fixations. During NREM sleep, eye movements were slow and mostly unconjugated. The two eyes moved upwardly and in the abducting direction, producing a tonic divergence and elevation of the visual axis. During the transition period between NREM and REM sleep, rapid monocular eye movements of low amplitude in the abducting direction occurred in coincidence with ponto-geniculo-occipital waves. Along REM sleep, the eyes tended to maintain a tonic convergence and depression, broken by high-frequency bursts of complex rapid eye movements. In the horizontal plane, each eye movement in the burst comprised two consecutive movements in opposite directions, which were more evident in the eye that performed the abducting movements. In the vertical plane, rapid eye movements were always upward. Comparisons of the characteristics of eye movements during the sleep-wake cycle reveal the uniqueness of eye movements during sleep, and the noteworthy existence of tonic and phasic phenomena in the oculomotor system, not observed until now.

Eye temperature and heart rate variability of calves disbudded with or without local anaesthetic.

PubMed

Stewart, M; Stafford, K J; Dowling, S K; Schaefer, A L; Webster, J R

2008-03-18

The possibility that pain can be detected from changes in eye temperature and heart rate variability (HRV) during disbudding was examined in thirty calves, randomly assigned to four treatments: 1) sham handling (control), 2) local anaesthetic (LA, cornual nerve injection) and sham disbudded, 3) sham LA and disbudded, 4) LA and disbudded. During a 40 min sampling period, maximum eye temperature, behavior and HRV parameters were recorded continuously. One week later, twelve disbudded calves were injected with adrenocorticotrophic hormone (ACTH) or saline and maximum eye temperature was recorded. There was a rapid drop in eye temperature during the 5 min following disbudding without LA (P<0.05). Eye temperature then increased and was higher than baseline over the remaining sampling period following both disbudding procedures (P<0.001), a response which could not be explained by increased physical activity LA increased eye temperature prior to disbudding (P<0.001). Heart rate increased (P<0.001) during the 5 min following disbudding with and without LA, however, LF/HF ratio only increased during this time (P<0.01) following disbudding without LA. Eye temperature did not change following ACTH, suggesting that hypothalamus-pituitary-adrenal axis (HPA) activity is not responsible for the changes in eye temperature following disbudding. The increase in LF/HF ratio following disbudding without LA suggests an acute sympathetic response to pain, which could be responsible for the drop in eye temperature via vasoconstriction. HRV and eye temperature together may be a useful non-invasive and more immediate index of pain than HPA activity alone.

Identification of a pharmacological target for genioglossus reactivation throughout sleep.

PubMed

Grace, Kevin P; Hughes, Stuart W; Horner, Richard L

2014-01-01

Obstructive sleep apnea (OSA) is a significant public health problem caused by repeated episodes of upper airway closure that occur only during sleep. Attempts to treat OSA pharmacologically have been unsuccessful because there has not been identification of a target operating at cranial motor nuclei, blockade of which can reactivate pharyngeal muscle activity throughout sleep. Increasing potassium conductance is a common mechanism by which state-dependent neuromodulators reduce motoneuron excitability. Therefore, we aimed to determine if potassium channel blockade is an effective strategy to reactivate the pharyngeal musculature throughout sleep. In rats chronically instrumented for recording sleep-wake states and respiratory motor activities, we locally microperfused pharmacological agents into the hypoglossal motor pool to modulate potassium channels of three major classes: inwardly rectifying, two-pore domain, and voltage-gated. Microperfusion of the inwardly rectifying potassium channel blocker, barium, as well as the voltage-gated potassium channel blockers, tetraethylammonium and 4-aminopyridine, increased tonic and respiratory-related genioglossus activities throughout nonrapid eye movement (non-REM) and rapid eye movement (REM) sleep to 133-300% of levels present during baseline wakefulness. In contrast, microperfusion of methanandamide (TWIK-related acid-sensitive potassium [TASK] channel blocker/cannabinoid receptor agonist) activated genioglossus in wakefulness but not in sleep. These findings establish proof-of-principle that targeted blockade of certain potassium channels at the hypoglossal motor pool is an effective strategy for reversing upper airway hypotonia and causing sustained reactivation of genioglossus throughout nonrapid eye movement and rapid eye movement sleep. These findings identify an important new direction for translational approaches to the pharmacological treatment of obstructive sleep apnea.

Increases in cAMP, MAPK Activity and CREB Phosphorylation during REM Sleep: Implications for REM Sleep and Memory Consolidation

PubMed Central

Luo, Jie; Phan, Trongha X.; Yang, Yimei; Garelick, Michael G.; Storm, Daniel R.

2013-01-01

The cyclic adenosine monophosphate (cAMP), mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB) transcriptional pathway is required for consolidation of hippocampus-dependent memory. In mice, this pathway undergoes a circadian oscillation required for memory persistence that reaches a peak during the daytime. Since mice exhibit polyphasic sleep patterns during the day, this suggested the interesting possibility that cAMP, MAPK activity and CREB phosphorylation may be elevated during sleep. Here, we report that cAMP, phospho-p44/42 MAPK and phospho-CREB are higher in rapid eye movement (REM) sleep compared to awake mice but are not elevated in non-rapid eye movement (NREM) sleep. This peak of activity during REM sleep does not occur in mice lacking calmodulin-stimulated adenylyl cyclases, a mouse strain that learns but cannot consolidate hippocampus-dependent memory. We conclude that a preferential increase in cAMP, MAPK activity and CREB phosphorylation during REM sleep may contribute to hippocampus-dependent memory consolidation. PMID:23575844

Variation of electroencephalographic activity during non-rapid eye movement and rapid eye movement sleep with phase of circadian melatonin rhythm in humans.

PubMed Central

Dijk, D J; Shanahan, T L; Duffy, J F; Ronda, J M; Czeisler, C A

1997-01-01

1. The circadian pacemaker regulates the timing, structure and consolidation of human sleep. The extent to which this pacemaker affects electroencephalographic (EEG) activity during sleep remains unclear. 2. To investigate this, a total of 1.22 million power spectra were computed from EEGs recorded in seven men (total, 146 sleep episodes; 9 h 20 min each) who participated in a one-month-long protocol in which the sleep-wake cycle was desynchronized from the rhythm of plasma melatonin, which is driven by the circadian pacemaker. 3. In rapid eye movement (REM) sleep a small circadian variation in EEG activity was observed. The nadir of the circadian rhythm of alpha activity (8.25-10.5 Hz) coincided with the end of the interval during which plasma melatonin values were high, i.e. close to the crest of the REM sleep rhythm. 4. In non-REM sleep, variation in EEG activity between 0.25 and 11.5 Hz was primarily dependent on prior sleep time and only slightly affected by circadian phase, such that the lowest values coincided with the phase of melatonin secretion. 5. In the frequency range of sleep spindles, high-amplitude circadian rhythms with opposite phase positions relative to the melatonin rhythm were observed. Low-frequency sleep spindle activity (12.25-13.0 Hz) reached its crest and high-frequency sleep spindle activity (14.25-15.5 Hz) reached its nadir when sleep coincided with the phase of melatonin secretion. 6. These data indicate that the circadian pacemaker induces changes in EEG activity during REM and non-REM sleep. The changes in non-REM sleep EEG spectra are dissimilar from the spectral changes induced by sleep deprivation and exhibit a close temporal association with the melatonin rhythm and the endogenous circadian phase of sleep consolidation. PMID:9457658

Relieving the attentional blink in the amblyopic brain with video games.

PubMed

Li, Roger W; Ngo, Charlie V; Levi, Dennis M

2015-02-26

Video game play induces a generalized recovery of a range of spatial visual functions in the amblyopic brain. Here we ask whether video game play also alters temporal processing in the amblyopic brain. When visual targets are presented in rapid succession, correct identification of the first target (T1) can interfere with identification of the second (T2). This is known as the "attentional blink". We measured the attentional blink in each eye of adults with amblyopia before and after 40 hours of active video game play, using a rapid serial visual presentation technique. After videogame play, we observed a ~40% reduction in the attentional blink (identifying T2 200 ms after T1) seen through the amblyopic eye and this improvement in performance transferred substantially to the untrained fellow sound eye. Our experiments show that the enhanced performance cannot be simply explained by eye patching alone, or to improved visual acuity, but is specific to videogame experience. Thus, videogame training might have important therapeutic applications for amblyopia and other visual brain disorders.

Electroencephalographic prodromal markers of dementia across conscious states in Parkinson’s disease

PubMed Central

Latreille, Véronique; Gaudet-Fex, Benjamin; Rodrigues-Brazète, Jessica; Panisset, Michel; Chouinard, Sylvain; Postuma, Ronald B.

2016-01-01

Abstract In Parkinson’s disease, electroencephalographic abnormalities during wakefulness and non-rapid eye movement sleep (spindles) were found to be predictive biomarkers of dementia. Because rapid eye movement sleep is regulated by the cholinergic system, which shows early degeneration in Parkinson’s disease with cognitive impairment, anomalies during this sleep stage might mirror dementia development. In this prospective study, we examined baseline electroencephalographic absolute spectral power across three states of consciousness (non-rapid eye movement sleep, rapid eye movement sleep, and wakefulness) in 68 non-demented patients with Parkinson’s disease and 44 healthy controls. All participants underwent baseline polysomnographic recordings and a comprehensive neuropsychological assessment. Power spectral analyses were performed on standard frequency bands. Dominant occipital frequency during wakefulness and ratios of slow-to-fast frequencies during rapid eye movement sleep and wakefulness were also computed. At follow-up (an average 4.5 years after baseline), 18 patients with Parkinson’s disease had developed dementia and 50 patients remained dementia-free. In rapid eye movement sleep, patients with Parkinson’s disease who later developed dementia showed, at baseline, higher absolute power in delta and theta bands and a higher slowing ratio, especially in temporal, parietal, and occipital regions, compared to patients who remained dementia-free and controls. In non-rapid eye movement sleep, lower baseline sigma power in parietal cortical regions also predicted development of dementia. During wakefulness, patients with Parkinson’s disease who later developed dementia showed lower dominant occipital frequency as well as higher delta and slowing ratio compared to patients who remained dementia-free and controls. At baseline, higher slowing ratios in temporo-occipital regions during rapid eye movement sleep were associated with poor performance on visuospatial tests in patients with Parkinson’s disease. Using receiver operating characteristic curves, we found that best predictors of dementia in Parkinson’s disease were rapid eye movement sleep slowing ratios in posterior regions, wakefulness slowing ratios in temporal areas, and lower dominant occipital frequency. These results suggest that electroencephalographic slowing during sleep is a new promising predictive biomarker for Parkinson’s disease dementia, perhaps as a marker of cholinergic denervation. PMID:26912643

Selectively driving cholinergic fibers optically in the thalamic reticular nucleus promotes sleep

PubMed Central

Ni, Kun-Ming; Hou, Xiao-Jun; Yang, Ci-Hang; Dong, Ping; Li, Yue; Zhang, Ying; Jiang, Ping; Berg, Darwin K; Duan, Shumin; Li, Xiao-Ming

2016-01-01

Cholinergic projections from the basal forebrain and brainstem are thought to play important roles in rapid eye movement (REM) sleep and arousal. Using transgenic mice in which channelrhdopsin-2 is selectively expressed in cholinergic neurons, we show that optical stimulation of cholinergic inputs to the thalamic reticular nucleus (TRN) activates local GABAergic neurons to promote sleep and protect non-rapid eye movement (NREM) sleep. It does not affect REM sleep. Instead, direct activation of cholinergic input to the TRN shortens the time to sleep onset and generates spindle oscillations that correlate with NREM sleep. It does so by evoking excitatory postsynaptic currents via α7-containing nicotinic acetylcholine receptors and inducing bursts of action potentials in local GABAergic neurons. These findings stand in sharp contrast to previous reports of cholinergic activity driving arousal. Our results provide new insight into the mechanisms controlling sleep. DOI: http://dx.doi.org/10.7554/eLife.10382.001 PMID:26880556

Substance P and the neurokinin-1 receptor regulate electroencephalogram non-rapid eye movement sleep slow-wave activity locally

PubMed Central

Zielinski, Mark R.; Karpova, Svetlana A.; Yang, Xiaomei; Gerashchenko, Dmitry

2014-01-01

The neuropeptide substance P is an excitatory neurotransmitter produced by various cells including neurons and microglia that is involved in regulating inflammation and cerebral blood flow—functions that affect sleep and slow-wave activity (SWA). Substance P is the major ligand for the neurokinin-1 receptor (NK-1R), which is found throughout the brain including the cortex. The NK-1R is found on sleep-active cortical neurons expressing neuronal nitric oxide synthase whose activity is associated with SWA. We determined the effects of local cortical administration of a NK-1R agonist (substance P-fragment 1, 7) and a NK-1R antagonist (CP96345) on sleep and SWA in mice. The NK-1R agonist significantly enhanced SWA for several hours when applied locally to the cortex of the ipsilateral hemisphere as the electroencephalogram (EEG) electrode but not after application to the contralateral hemisphere when compared to saline vehicle control injections. In addition, a significant compensatory reduction in SWA was found after the NK-1R agonist-induced enhancements in SWA. Conversely, injections of the NK-1R antagonist into the cortex of the ipsilateral hemisphere of the EEG electrode attenuated SWA compared to vehicle injections but this effect was not found after injections of the NK-1R antagonist into contralateral hemisphere as the EEG electrode. Non-rapid eye movement sleep and rapid eye movement sleep duration responses after NK-1R agonist and antagonist injections were not significantly different from the responses to the vehicle. Our findings indicate that the substance P and the NK-1R are involved in regulating SWA locally. PMID:25301750

Rapid assessment method for prevalence and intensity of Loa loa infection.

PubMed Central

Takougang, Innocent; Meremikwu, Martin; Wandji, Samuel; Yenshu, Emmanuel V.; Aripko, Ben; Lamlenn, Samson B.; Eka, Braide L.; Enyong, Peter; Meli, Jean; Kale, Oladele; Remme, Jan H.

2002-01-01

OBJECTIVE: To assess the validity of observations on eye worm and Calabar swellings for the rapid assessment of the prevalence and intensity of loiasis at the community level. METHOD: A total of 12895 individuals over the age of 15 years living in 102 communities in Cameroon and Nigeria took part in the study. A standardized questionnaire was administered to participants from whom finger-prick blood samples were collected and examined for Loa loa microfilariae. Rapid assessments of the prevalence and intensity of loiasis were made on the basis of a history of eye worm or Calabar swellings. FINDINGS: There was a strong correlation between the indices of the rapid assessment procedures and the parasitological indices of L. loa endemicity. The rapid assessment indices were effective in diagnosing high-risk communities (sensitivity 94-100%; specificity 66-92%). The highest sensitivity (100%) and specificity (92%) were obtained with a rapid assessment procedure based on a history of eye worm lasting 1-7 days together with confirmation by the guided recognition of a photograph of adult L. loa in the eye. CONCLUSION: Rapid assessment of the prevalence and intensity of loiasis at the community level can be achieved using a procedure based on the history of eye worm lasting 1-7 days together with confirmation by the guided recognition of a photograph of an adult L. loa in the eye. PMID:12481206

EXTRAOCULAR MUSCLE ACTIVITY, RAPID EYE MOVEMENTS, AND THE DEVELOPMENT OF ACTIVE AND QUIET SLEEP

PubMed Central

Seelke, Adele M. H.; Karlsson, Karl Æ.; Gall, Andrew J.; Blumberg, Mark S.

2008-01-01

Rapid eye movements (REMs), traditionally measured using the electrooculogram (EOG), help to characterize active sleep in adults. In early infancy, however, they are not clearly expressed. Here we measure extraocular muscle activity in infant rats at 3 days of age (P3), P8, and P14–15 in order to assess the ontogeny of REMs and their relationship with other forms of sleep-related phasic activity. We find that the causal relationship between extraocular muscle twitches and REMs strengthens during the first two postnatal weeks, reflecting increased control of the extraocular muscles over eye movements. As early as P3, however, phasic bursts of extraocular muscle twitching occur in synchrony with twitching in other muscle groups, producing waves of phasic activity interspersed with brief periods of quiescence. Surprisingly, the tone of the extraocular muscles, invisible to standard EOG measures, fluctuates in synchrony with the tone of other muscle groups; focal electrical stimulation within the dorsolateral pontine tegmentum, an area that has been shown to contain wake-on neurons in P8 rats, results in the simultaneous activation of high tone in both nuchal and extraocular muscles. Finally, when state-dependent neocortical electroencephalographic activity was observed at P14, it had already integrated fully with sleep and wakefulness as defined using electromyographic criteria alone; this finding is not consistent with the notion that active sleep in infants at this age is “half-activated.” All together, these results indicate exquisite temporal organization of sleep soon after birth and highlight the possible functional implications of homologous activational states in striated muscle and neocortex. PMID:16115214

Rapid Eye Movement and Non-Rapid Eye Movement Sleep Contributions in Memory Consolidation and Resistance to Retroactive Interference for Verbal Material

PubMed Central

Deliens, Gaétane; Leproult, Rachel; Neu, Daniel; Peigneux, Philippe

2013-01-01

Study Objectives: To test the hypothesis that rapid eye movement (REM) sleep contributes to the consolidation of new memories, whereas non-rapid eye movement (NREM) sleep contributes to the prevention of retroactive interference. Design: Randomized, crossover study. Setting: Two sessions of either a morning nap or wakefulness. Participants: Twenty-five healthy young adults. Interventions: Declarative learning of word pairs followed by a nap or a wake interval, then learning of interfering word pairs and delayed recall of list A. Measurements and Results: After a restricted night (24:00-06:00), participants learned a list of word pairs (list A). They were then required to either take a nap or stay awake during 45 min, after which they learned a second list of word pairs (list B) and then had to recall list A. Fifty percent of word pairs in list B shared the first word with list A, resulting in interference. Ten subjects exhibited REM sleep whereas 13 subjects exhibited NREM stage 3 (N3) sleep. An interference effect was observed in the nap but not in the wake condition. In post-learning naps, N3 sleep was associated with a reduced interference effect, which was not the case for REM sleep. Moreover, participants exhibiting N3 sleep in the post-learning nap condition also showed a reduced interference effect in the wake condition, suggesting a higher protection ability against interference. Conclusion: Our results partly support the hypothesis that non-rapid eye movement sleep contributes in protecting novel memories against interference. However, rapid eye movement sleep-related consolidation is not evidenced. Citation: Deliens G; Leproult R; Neu D; Peigneux P. Rapid eye movement and non-rapid eye movement sleep contributions in memory consolidation and resistance to retroactive interference for verbal material. SLEEP 2013;36(12):1875-1883. PMID:24293762

Sleep in the nocturnal primate, Aotus trivirgatus.

NASA Technical Reports Server (NTRS)

Perachio, A. A.

1971-01-01

Measurement of the cycles of wakefulness and stages of sleep in owl monkeys during 24-hr periods divided into half dark and half light segments. Recordings of electrophysiological activity were used. Reversal of the sequence of light and dark served to test the influence of environmental lighting on the sleep-wakefulness cycles. The sleep patterns of owl monkeys expressed in percentage of rapid eye movement (REM) and nonrapid eye movement (NREM) were compared with those of a closely related New World monkey species, Saimiri Sciureus.

A prominent role for amygdaloid complexes in the Variability in Heart Rate (VHR) during Rapid Eye Movement (REM) sleep relative to wakefulness.

PubMed

Desseilles, Martin; Vu, Thanh Dang; Laureys, Steven; Peigneux, Philippe; Degueldre, Christian; Phillips, Christophe; Maquet, Pierre

2006-09-01

Rapid eye movement sleep (REMS) is associated with intense neuronal activity, rapid eye movements, muscular atonia and dreaming. Another important feature in REMS is the instability in autonomic, especially in cardiovascular regulation. The neural mechanisms underpinning the variability in heart rate (VHR) during REMS are not known in detail, especially in humans. During wakefulness, the right insula has frequently been reported as involved in cardiovascular regulation but this might not be the case during REMS. We aimed at characterizing the neural correlates of VHR during REMS as compared to wakefulness and to slow wave sleep (SWS), the other main component of human sleep, in normal young adults, based on the statistical analysis of a set of H(2)(15)O positron emission tomography (PET) sleep data acquired during SWS, REMS and wakefulness. The results showed that VHR correlated more tightly during REMS than during wakefulness with the rCBF in the right amygdaloid complex. Moreover, we assessed whether functional relationships between amygdala and any brain area changed depending the state of vigilance. Only the activity within in the insula was found to covary with the amygdala, significantly more tightly during wakefulness than during REMS in relation to the VHR. The functional connectivity between the amygdala and the insular cortex, two brain areas involved in cardiovascular regulation, differs significantly in REMS as compared to wakefulness. This suggests a functional reorganization of central cardiovascular regulation during REMS.

Eye Size at Birth in Prosimian Primates: Life History Correlates and Growth Patterns

PubMed Central

Cummings, Joshua R.; Muchlinski, Magdalena N.; Kirk, E. Christopher; Rehorek, Susan J.; DeLeon, Valerie B.; Smith, Timothy D.

2012-01-01

Background Primates have large eyes relative to head size, which profoundly influence the ontogenetic emergence of facial form. However, growth of the primate eye is only understood in a narrow taxonomic perspective, with information biased toward anthropoids. Methodology/Principal Findings We measured eye and bony orbit size in perinatal prosimian primates (17 strepsirrhine taxa and Tarsius syrichta) to infer the extent of prenatal as compared to postnatal eye growth. In addition, multiple linear regression was used to detect relationships of relative eye and orbit diameter to life history variables. ANOVA was used to determine if eye size differed according to activity pattern. In most of the species, eye diameter at birth measures more than half of that for adults. Two exceptions include Nycticebus and Tarsius, in which more than half of eye diameter growth occurs postnatally. Ratios of neonate/adult eye and orbit diameters indicate prenatal growth of the eye is actually more rapid than that of the orbit. For example, mean neonatal transverse eye diameter is 57.5% of the adult value (excluding Nycticebus and Tarsius), compared to 50.8% for orbital diameter. If Nycticebus is excluded, relative gestation age has a significant positive correlation with relative eye diameter in strepsirrhines, explaining 59% of the variance in relative transverse eye diameter. No significant differences were found among species with different activity patterns. Conclusions/Significance The primate developmental strategy of relatively long gestations is probably tied to an extended period of neural development, and this principle appears to apply to eye growth as well. Our findings indicate that growth rates of the eye and bony orbit are disassociated, with eyes growing faster prenatally, and the growth rate of the bony orbit exceeding that of the eyes after birth. Some well-documented patterns of orbital morphology in adult primates, such as the enlarged orbits of nocturnal species, mainly emerge during postnatal development. PMID:22567127

Quality of life in patients with an idiopathic rapid eye movement sleep behaviour disorder in Korea.

PubMed

Kim, Keun Tae; Motamedi, Gholam K; Cho, Yong Won

2017-08-01

There have been few quality of life studies in patients with idiopathic rapid eye movement sleep behaviour disorder. We compared the quality of life in idiopathic rapid eye movement sleep behaviour disorder patients to healthy controls, patients with hypertension, type 2 diabetes mellitus without complication and idiopathic restless legs syndrome. Sixty patients with idiopathic rapid eye movement sleep behaviour disorder (24 female; mean age: 61.43 ± 8.99) were enrolled retrospectively. The diagnosis was established based on sleep history, overnight polysomnography, neurological examination and Mini-Mental State Examination to exclude secondary rapid eye movement sleep behavior disorder. All subjects completed questionnaires, including the Short Form 36-item Health Survey for quality of life. The total quality of life score in idiopathic rapid eye movement sleep behaviour disorder (70.63 ± 20.83) was lower than in the healthy control group (83.38 ± 7.96) but higher than in the hypertension (60.55 ± 24.82), diabetes mellitus (62.42 ± 19.37) and restless legs syndrome (61.77 ± 19.25) groups. The total score of idiopathic rapid eye movement sleep behaviour disorder patients had a negative correlation with the Pittsburg Sleep Quality Index (r = -0.498, P < 0.001), Insomnia Severity Index (r = -0.645, P < 0.001) and the Beck Depression Inventory-2 (r = -0.694, P < 0.001). Multiple regression showed a negative correlation between the Short Form 36-item Health Survey score and the Insomnia Severity Index (β = -1.100, P = 0.001) and Beck Depression Inventory-2 (β = -1.038, P < 0.001). idiopathic rapid eye movement sleep behaviour disorder had a significant negative impact on quality of life, although this effect was less than that of other chronic disorders. This negative effect might be related to a depressive mood associated with the disease. © 2016 European Sleep Research Society.

Lhx6-positive GABA-releasing neurons of the zona incerta promote sleep

PubMed Central

Liu, Kai; Kim, Juhyun; Kim, Dong Won; Zhang, Yi Stephanie; Bao, Hechen; Denaxa, Myrto; Lim, Szu-Aun; Kim, Eileen; Liu, Chang; Wickersham, Ian R.; Pachnis, Vassilis; Hattar, Samer; Song, Juan; Brown, Solange P.; Blackshaw, Seth

2017-01-01

Multiple populations of wake-promoting neurons have been characterized in mammals, but few sleep-promoting neurons have been identified1. Wake-promoting cell types include hypocretin and GABA (γ-aminobutyric-acid)-releasing neurons of the lateral hypothalamus, which promote the transition to wakefulness from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep2,3. Here we show that a subset of GABAergic neurons in the mouse ventral zona incerta, which express the LIM homeodomain factor Lhx6 and are activated by sleep pressure, both directly inhibit wake-active hypocretin and GABAergic cells in the lateral hypothalamus and receive inputs from multiple sleep–wake-regulating neurons. Conditional deletion of Lhx6 from the developing diencephalon leads to decreases in both NREM and REM sleep. Furthermore, selective activation and inhibition of Lhx6-positive neurons in the ventral zona incerta bidirectionally regulate sleep time in adult mice, in part through hypocretin-dependent mechanisms. These studies identify a GABAergic subpopulation of neurons in the ventral zona incerta that promote sleep. PMID:28847002

Contrasting expressions of aggressive behavior released by lesions of the central nucleus of the amygdala during wakefulness and rapid eye movement sleep without atonia in cats.

PubMed

Zagrodzka, J; Hedberg, C E; Mann, G L; Morrison, A R

1998-06-01

Whether damage to the central nucleus of the amygdala (Ace) contributes to the predatorylike attack sometimes observed in rapid eye movement sleep without atonia (REM-A), created in cats by bilateral pontine lesions, was examined. Such lesions eliminate REM sleep skeletal muscle atonia and release elaborate behavior. Unilateral damage to the Ace alone increased affective defensive aggressive behavior toward humans and conspecifics without altering predatory behavior in wakefulness. Pontine lesions added at loci normally not leading to aggression induced predatorylike attacks in REM-A as well as the waking affective defense. Alterations of autonomic activity, the absence of relevant environmental stimuli in REM-A, or both may explain the state-related differences.

Influence of experimental esophageal acidification on sleep bruxism: a randomized trial.

PubMed

Ohmure, H; Oikawa, K; Kanematsu, K; Saito, Y; Yamamoto, T; Nagahama, H; Tsubouchi, H; Miyawaki, S

2011-05-01

The aim of this cross-over, randomized, single-blinded trial was to examine whether intra-esophageal acidification induces sleep bruxism (SB). Polysomnography with electromyogram (EMG) of masseter muscle, audio-video recording, and esophageal pH monitoring were performed in a sleep laboratory. Twelve healthy adult males without SB participated. Intra-esophageal infusions of 5-mL acidic solution (0.1 N HCl) or saline were administered. The frequencies of EMG bursts, rhythmic masticatory muscle activity (RMMA) episodes, grinding noise, and the RMMA/microarousal ratio were significantly higher in the 20-minute period after acidic infusion than after saline infusion. RMMA episodes including SB were induced by esophageal acidification. This trial is registered with the UMIN Clinical Trials Registry, UMIN000002923. ASDA, American Sleep Disorders Association; EMG, electromyogram; GER, gastroesophageal reflux; LES, lower esophageal sphincter; NREM, non-rapid eye movement; REM, rapid eye movement; RMMA, rhythmic masticatory muscle activity; SB, sleep bruxism; SD, standard deviation; UES, upper esophageal sphincter.

Coming to grips with a "new" state of consciousness: the study of rapid-eye-movement sleep in the 1960s.

PubMed

Morrison, Adrian R

2013-01-01

The recognition of rapid-eye-movement sleep (REM) and its association with dreaming in 1953 by Aserinsky and Kleitman opened a new world to explore in the brain. Discussions at two major symposia in the early 1960s reveal that a state with characteristics resembling both wakefulness and sleep was overturning accepted views of the regulation of the two states. Participants grappled with the idea that cortical activation could occur during sleep. They struggled with picking a name that would capture the essence of REM without focusing on just one aspect of the state. Questioning whether REM in cats could be homologous with that of humans suggested an anthropocentric focus on human dreaming as the essence of the state. The need for biochemical studies was evident given that deprivation of REM caused a rebound in the amount of subsequent REM, which indicated that simple synaptic activity could not support this phenomenon.

Vitreous penetration of levofloxacin in the uninflamed phakic human eye

PubMed Central

Herbert, E N; Pearce, I A; McGalliard, J; Wong, D; Groenewald, C

2002-01-01

Aims: To assess the vitreous penetration of oral levofloxacin (a new fluoroquinolone antibiotic with improved Gram positive activity) in uninflamed phakic eyes. Methods: 15 patients for macula hole surgery were recruited to the study. 10 received a single 500 mg dose of levofloxacin by mouth preoperatively. Five acted as controls. Serum and undiluted vitreous samples were obtained at surgery and analysed by HPLC. Results: Levofloxacin was detectable 2.5 hours after administration in the vitreous. A peak concentration of 1.6 μg/ml (or mg/l) was measured between 2.5 and 4 hours post-dose. Conclusion: Oral levofloxacin reaches the vitreous rapidly in the uninflamed phakic eye. Levels did not reach MIC90 for the commonest infecting organisms. Nevertheless, levofloxacin would be expected to be active against a higher proportion of infecting organisms than either ciprofloxacin or ofloxacin. PMID:11914204

Fluid Mixing in the Eye Under Rapid Eye Movement

NASA Astrophysics Data System (ADS)

Huang, Jinglin; Gharib, Morteza

2017-11-01

Drug injection is an important technique in certain treatments of eye diseases. The efficacy of chemical mixing plays an important role in determining pharmacokinetics of injected drugs. In this study, we build a device to study the chemical mixing behavior in a spherical structure. The mixing process is visualized and analyzed qualitatively. We hope to understand the chemical convection and diffusion behaviors in correlation with controlled rapid mechanical movements. The results will have potential applications in treatment of eye diseases. Resnick Institute at Caltech.

Cardiac autonomic denervation in Parkinson's disease is linked to REM sleep behavior disorder.

PubMed

Postuma, Ronald B; Montplaisir, Jacques; Lanfranchi, Paola; Blais, Hélène; Rompré, Sylvie; Colombo, Roberto; Gagnon, Jean-François

2011-07-01

Recent studies have suggested a close connection between autonomic dysfunction and rapid eye movement sleep behavior disorder, which differs in nature from other early-stage markers of Parkinson's disease. In this study we examined the relationship between rapid eye movement sleep behavior disorder and autonomic dysfunction in Parkinson's disease as measured by cardiac beat-to-beat variability. In 53 patients with Parkinson's disease and 36 controls, electrocardiographic trace from a polysomnogram was assessed for measures of beat-to-beat RR variability including RR-standard deviation and frequency domains (low- and high-frequency components). Results were compared between patients with Parkinson's disease and controls, and between patients with Parkinson's disease with and without rapid eye movement sleep behavior disorder. On numerous cardiac autonomic measures, patients with Parkinson's disease showed clear abnormalities compared with controls. However, these abnormalities were confined only to those patients with associated rapid eye movement sleep behavior; those without were not different than controls. As with other clinical autonomic variables, cardiac autonomic denervation is predominantly associated not with Parkinson's disease itself, but with the presence of rapid eye movement sleep behavior disorder. Copyright © 2011 Movement Disorder Society.

Effects of Meditation Practice on Spontaneous Eye Blink Rate

PubMed Central

Kruis, Ayla; Slagter, Heleen A.; Bachhuber, David R.W.; Davidson, Richard J.; Lutz, Antoine

2016-01-01

A rapidly growing body of research suggests that meditation can change brain and cognitive functioning. Yet little is known about the neurochemical mechanisms underlying meditation-related changes in cognition. Here we investigated the effects of meditation on spontaneous Eye Blink Rates (sEBR), a non-invasive peripheral correlate of striatal dopamine activity. Previous studies have shown a relationship between sEBR and cognitive functions such as mind-wandering, cognitive flexibility, and attention–functions that are also affected by meditation. We therefore expected that long-term meditation practice would alter eye-blink activity. To test this, we recorded baseline sEBR and Inter Eye-Blink Intervals (IEBI) in long-term meditators (LTM) and meditation naive participants (MNP). We found that LTM not only blinked less frequently, but also showed a different eye-blink pattern than MNP. This pattern had good to high degree of consistency over three time points. Moreover, we examined the effects of an 8 week-course of Mindfulness Based Stress Reduction (MBSR) on sEBR and IEBI, compared to an active control group and a waitlist-control group. No effect of short-term meditation practice was found. Finally, we investigated whether different types of meditation differentially alter eye blink activity by measuring sEBR and IEBI after a full day of two kinds of meditation practices in the LTM. No effect of meditation type was found. Taken together, these findings may suggest either that individual difference in dopaminergic neurotransmission is a self-selection factor for meditation practice, or that long-term, but not short-term meditation practice induces stable changes in baseline striatal dopaminergic functioning. PMID:26871460

Eye and head motion during head turns in spaceflight

NASA Technical Reports Server (NTRS)

Thornton, William E.; Uri, John J.; Moore, Thomas P.; Pool, Sam L.

1988-01-01

Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.

Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation

PubMed Central

Lee, Michael L.; Katsuyama, Ângela M.; Duge, Leanne S.; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J.; de la Iglesia, Horacio O.

2016-01-01

Study Objectives: Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. Methods: We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. Results: When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Conclusions: Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation. Citation: Lee ML, Katsuyama AM, Duge LS, Sriram C, Krushelnytskyy M, Kim JJ, de la Iglesia HO. Fragmentation of rapid eye movement and nonrapid eye movement sleep without total sleep loss impairs hippocampus-dependent fear memory consolidation. SLEEP 2016;39(11):2021–2031. PMID:27568801

Early and Later Life Stress Alter Brain Activity and Sleep in Rats

PubMed Central

Mrdalj, Jelena; Pallesen, Ståle; Milde, Anne Marita; Jellestad, Finn Konow; Murison, Robert; Ursin, Reidun; Bjorvatn, Bjørn; Grønli, Janne

2013-01-01

Exposure to early life stress may profoundly influence the developing brain in lasting ways. Neuropsychiatric disorders associated with early life adversity may involve neural changes reflected in EEG power as a measure of brain activity and disturbed sleep. The main aim of the present study was for the first time to characterize possible changes in adult EEG power after postnatal maternal separation in rats. Furthermore, in the same animals, we investigated how EEG power and sleep architecture were affected after exposure to a chronic mild stress protocol. During postnatal day 2–14 male rats were exposed to either long maternal separation (180 min) or brief maternal separation (10 min). Long maternally separated offspring showed a sleep-wake nonspecific reduction in adult EEG power at the frontal EEG derivation compared to the brief maternally separated group. The quality of slow wave sleep differed as the long maternally separated group showed lower delta power in the frontal-frontal EEG and a slower reduction of the sleep pressure. Exposure to chronic mild stress led to a lower EEG power in both groups. Chronic exposure to mild stressors affected sleep differently in the two groups of maternal separation. Long maternally separated offspring showed more total sleep time, more episodes of rapid eye movement sleep and higher percentage of non-rapid eye movement episodes ending in rapid eye movement sleep compared to brief maternal separation. Chronic stress affected similarly other sleep parameters and flattened the sleep homeostasis curves in all offspring. The results confirm that early environmental conditions modulate the brain functioning in a long-lasting way. PMID:23922857

Dreaming and electroencephalographic changes during anesthesia maintained with propofol or desflurane.

PubMed

Leslie, Kate; Sleigh, Jamie; Paech, Michael J; Voss, Logan; Lim, Chiew Woon; Sleigh, Callum

2009-09-01

Dream recall is reportedly more common after propofol than after volatile anesthesia, but this may be due to delayed emergence or more amnesia after longer-acting volatiles. The electroencephalographic signs of dreaming during anesthesia and the differences between propofol and desflurane also are unknown. The authors therefore compared dream recall after propofol- or desflurane-maintained anesthesia and analyzed electroencephalographic patterns in dreamers and nondreamers and in propofol and desflurane patients for similarities to rapid eye movement and non-rapid eye movement sleep. Three hundred patients presenting for noncardiac surgery were randomized to receive propofol- or desflurane-maintained anesthesia. The raw electroencephalogram was recorded from induction until patients were interviewed about dreaming when they became first oriented postoperatively. Using spectral and ordinal methods, the authors quantified the amount of sleep spindle-like activity and high-frequency power in the electroencephalogram. The incidence of dream recall was similar for propofol (27%) and desflurane (28%) patients. Times to interview were similar (median 20 [range 4-114] vs. 17 [7-86] min; P = 0.1029), but bispectral index values at interview were lower (85 [69-98] vs. 92 [40-98]; P < 0.0001) in propofol than in desflurane patients. During surgery, the raw electroencephalogram of propofol patients showed more and faster spindle activity than in desflurane patients (P < 0.001). The raw electroencephalogram of dreamers showed fewer spindles and more high-frequency power than in nondreamers in the 5 min before interview (P < 0.05). Anesthetic-related dreaming seems to occur just before awakening and is associated with a rapid eye movement-like electroencephalographic pattern.

Rapid eye movement and non-rapid eye movement sleep contributions in memory consolidation and resistance to retroactive interference for verbal material.

PubMed

Deliens, Gaétane; Leproult, Rachel; Neu, Daniel; Peigneux, Philippe

2013-12-01

To test the hypothesis that rapid eye movement (REM) sleep contributes to the consolidation of new memories, whereas non-rapid eye movement (NREM) sleep contributes to the prevention of retroactive interference. Randomized, crossover study. Two sessions of either a morning nap or wakefulness. Twenty-five healthy young adults. Declarative learning of word pairs followed by a nap or a wake interval, then learning of interfering word pairs and delayed recall of list A. After a restricted night (24:00-06:00), participants learned a list of word pairs (list A). They were then required to either take a nap or stay awake during 45 min, after which they learned a second list of word pairs (list B) and then had to recall list A. Fifty percent of word pairs in list B shared the first word with list A, resulting in interference. Ten subjects exhibited REM sleep whereas 13 subjects exhibited NREM stage 3 (N3) sleep. An interference effect was observed in the nap but not in the wake condition. In post-learning naps, N3 sleep was associated with a reduced interference effect, which was not the case for REM sleep. Moreover, participants exhibiting N3 sleep in the post-learning nap condition also showed a reduced interference effect in the wake condition, suggesting a higher protection ability against interference. Our results partly support the hypothesis that non-rapid eye movement sleep contributes in protecting novel memories against interference. However, rapid eye movement sleep-related consolidation is not evidenced.

Computer Analysis of Eye Blood-Vessel Images

NASA Technical Reports Server (NTRS)

Wall, R. J.; White, B. S.

1984-01-01

Technique rapidly diagnoses diabetes mellitus. Photographs of "whites" of patients' eyes scanned by computerized image analyzer programmed to quantify density of small blood vessels in conjuctiva. Comparison with data base of known normal and diabetic patients facilitates rapid diagnosis.

Shield ulcers and plaques of the cornea in vernal keratoconjunctivitis.

PubMed

Cameron, J A

1995-06-01

Shield-shaped corneal ulcers and plaques are serious sight-threatening corneal manifestations of vernal keratoconjunctivitis. There are few reports describing the management of these patients and their outcomes. The clinical presentation, treatment, and outcome of 66 shield ulcers and/or plaques in 55 eyes of 41 patients with vernal keratoconjunctivitis were studied in this retrospective study of patients treated at King Khaled Eye Specialist Hospital during an 11-year period. Patients with shield ulcers where the base of the ulcer was transparent usually had rapid re-epithelialization and an excellent visual outcome with medical treatment alone. Patients with shield ulcers and visible plaque formation had delayed re-epithelialization when receiving only medical treatment. Complications of delayed re-epithelialization consisted of bacterial keratitis in five eyes, amblyopia in one eye, and strabismus in one patient. Patients with shield ulcers and/or plaques that do not re-epithelialize once active vernal keratoconjunctivitis has been controlled should have surgical intervention. In this series, a simple scraping of the base and margins of the ulcer with removal of the inflammatory material (i.e., the plaque) resulted in rapid re-epithelialization in 20 of 23 ulcers and plaques. An algorithm for treating shield ulcers and/or plaques is presented based on the experience at this institution.

Study of Sedative-Hypnotic Effects of Aloe vera L. Aqueous Extract through Behavioral Evaluations and EEG Recording in Rats

PubMed Central

Abdollahnejad, Fatemeh; Mosaddegh, Mahmoud; Nasoohi, Sanaz; Mirnajafi-Zadeh, Javad; Kamalinejad, Mohammad; Faizi, Mehrdad

2016-01-01

In this study, we investigated the sedative and hypnotic effects of the aqueous extract of Aloe vera on rats. In order to evaluate the overall hypnotic effects of the Aloe vera extract, open field and loss of righting reflex tests were primarily used. The sedative and hypnotic effects of the extract were then confirmed by detection of remarkable raise in the total sleeping time through analysis of electroencephalographic (EEG) recordings of animals. Analysis of the EEG recordings showed that there is concomitant change in Rapid Eye Movement (REM) and None Rapid Eye Movement (NREM) sleep in parallel with the prolonged total sleeping time. Results of the current research show that the extract has sedative-hypnotic effects on both functional and electrical activities of the brain. PMID:27610170

Regional cerebral glucose metabolic rate in human sleep assessed by positron emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchsbaum, M.S.; Wu, J.; Hazlett, E.

The cerebral metabolic rate of glucose was measured during nighttime sleep in 36 normal volunteers using positron emission tomography and fluorine-18-labeled 2-deoxyglucose (FDG). In comparison to waking controls, subjects given FDG during non-rapid eye movement (NREM) sleep showed about a 23% reduction in metabolic rate across the entire brain. This decrease was greater for the frontal than temporal or occipital lobes, and greater for basal ganglia and thalamus than cortex. Subjects in rapid eye movement (REM) sleep tended to have higher cortical metabolic rates than walking subjects. The cingulate gyrus was the only cortical structure to show a significant increasemore » in glucose metabolic rate in REM sleep in comparison to waking. The basal ganglia were relatively more active on the right in REM sleep and symmetrical in NREM sleep.« less

Excimer laser phototherapeutic keratectomy for shield ulcers and corneal plaques in vernal keratoconjunctivitis.

PubMed

Cameron, J A; Antonios, S R; Badr, I A

1995-01-01

Shield-shaped corneal ulcers and corneal plaques in vernal keratoconjunctivitis are associated with delayed epithelial healing, as well as the risks of infectious keratitis and sterile stromal ulceration. Significant visual impairment due to scarring and irregular astigmatism may result from central corneal lesions. Three eyes with central corneal lesions resulting from vernal keratoconjunctivitis were treated by excimer laser after active vernal keratoconjunctivitis was controlled and inflammatory plaque overlying the shield ulcers was removed. All three eyes showed rapid reepithelialization within 1 week. Spectacle-corrected visual acuity of 20/30 or better was obtained in each eye. In selected patients, excimer laser phototherapeutic keratectomy may be a useful adjunct in the treatment of shield-shaped corneal ulcers and plaques in vernal keratoconjunctivitis.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson's disease.

PubMed

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C; Mackay, Clare E; Hu, Michele T M

2016-08-01

SEE POSTUMA DOI101093/AWW131 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson's disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson's disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson's disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson's disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson's disease and 10 control subjects received (123)I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson's disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson's disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson's disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson's disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson's disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain.

Basal ganglia dysfunction in idiopathic REM sleep behaviour disorder parallels that in early Parkinson’s disease

PubMed Central

Rolinski, Michal; Griffanti, Ludovica; Piccini, Paola; Roussakis, Andreas A.; Szewczyk-Krolikowski, Konrad; Menke, Ricarda A.; Quinnell, Timothy; Zaiwalla, Zenobia; Klein, Johannes C.; Mackay, Clare E.

2016-01-01

Abstract See Postuma (doi:10.1093/aww131) for a scientific commentary on this article. Resting state functional magnetic resonance imaging dysfunction within the basal ganglia network is a feature of early Parkinson’s disease and may be a diagnostic biomarker of basal ganglia dysfunction. Currently, it is unclear whether these changes are present in so-called idiopathic rapid eye movement sleep behaviour disorder, a condition associated with a high rate of future conversion to Parkinson’s disease. In this study, we explore the utility of resting state functional magnetic resonance imaging to detect basal ganglia network dysfunction in rapid eye movement sleep behaviour disorder. We compare these data to a set of healthy control subjects, and to a set of patients with established early Parkinson’s disease. Furthermore, we explore the relationship between resting state functional magnetic resonance imaging basal ganglia network dysfunction and loss of dopaminergic neurons assessed with dopamine transporter single photon emission computerized tomography, and perform morphometric analyses to assess grey matter loss. Twenty-six patients with polysomnographically-established rapid eye movement sleep behaviour disorder, 48 patients with Parkinson’s disease and 23 healthy control subjects were included in this study. Resting state networks were isolated from task-free functional magnetic resonance imaging data using dual regression with a template derived from a separate cohort of 80 elderly healthy control participants. Resting state functional magnetic resonance imaging parameter estimates were extracted from the study subjects in the basal ganglia network. In addition, eight patients with rapid eye movement sleep behaviour disorder, 10 with Parkinson’s disease and 10 control subjects received 123I-ioflupane single photon emission computerized tomography. We tested for reduction of basal ganglia network connectivity, and for loss of tracer uptake in rapid eye movement sleep behaviour disorder and Parkinson’s disease relative to each other and to controls. Connectivity measures of basal ganglia network dysfunction differentiated both rapid eye movement sleep behaviour disorder and Parkinson’s disease from controls with high sensitivity (96%) and specificity (74% for rapid eye movement sleep behaviour disorder, 78% for Parkinson’s disease), indicating its potential as an indicator of early basal ganglia dysfunction. Rapid eye movement sleep behaviour disorder was indistinguishable from Parkinson’s disease on resting state functional magnetic resonance imaging despite obvious differences on dopamine transported single photon emission computerized tomography. Basal ganglia connectivity is a promising biomarker for the detection of early basal ganglia network dysfunction, and may help to identify patients at risk of developing Parkinson’s disease in the future. Future risk stratification using a polymodal approach could combine basal ganglia network connectivity with clinical and other imaging measures, with important implications for future neuroprotective trials in rapid eye movement sleep behaviour disorder. PMID:27297241

The influence of maximum running speed on eye size: a test of Leuckart's Law in mammals.

PubMed

Heard-Booth, Amber N; Kirk, E Christopher

2012-06-01

Vertebrate eye size is influenced by many factors, including body or head size, diet, and activity pattern. Locomotor speed has also been suggested to influence eye size in a relationship known as Leuckart's Law. Leuckart's Law proposes that animals capable of achieving fast locomotor speeds require large eyes to enhance visual acuity and avoid collisions with environmental obstacles. The selective influence of rapid flight has been invoked to explain the relatively large eyes of birds, but Leuckart's Law remains untested in nonavian vertebrates. This study investigates the relationship between eye size and maximum running speed in a diverse sample of mammals. Measures of axial eye diameter, maximum running speed, and body mass were collected from the published literature for 50 species from 10 mammalian orders. This analysis reveals that absolute eye size is significantly positively correlated with maximum running speed in mammals. Moreover, the relationship between eye size and running speed remains significant when the potentially confounding effects of body mass and phylogeny are statistically controlled. The results of this analysis are therefore consistent with the expectations of Leuckart's Law and demonstrate that faster-moving mammals have larger eyes than their slower-moving close relatives. Accordingly, we conclude that maximum running speed is one of several key selective factors that have influenced the evolution of eye size in mammals. Copyright © 2012 Wiley Periodicals, Inc.

Zinc-containing yeast extract promotes nonrapid eye movement sleep in mice.

PubMed

Cherasse, Yoan; Saito, Hitomi; Nagata, Nanae; Aritake, Kosuke; Lazarus, Michael; Urade, Yoshihiro

2015-10-01

Zinc is an essential trace element for humans and animals, being located, among other places, in the synaptic vesicles of cortical glutamatergic neurons and hippocampal mossy fibers in the brain. Extracellular zinc has the potential to interact with and modulate many different synaptic targets, including glutamate and GABA receptors. Because of the central role of these neurotransmitters in brain activity, we examined in this study the sleep-promoting activity of zinc by monitoring locomotor activity and electroencephalogram after its administration to mice. Zinc-containing yeast extract (40 and 80 mg/kg) dose dependently increased the total amount of nonrapid eye movement sleep and decreased the locomotor activity. However, this preparation did not change the amount of rapid eye movement sleep or show any adverse effects such as rebound of insomnia during a period of 24 h following the induction of sleep; whereas the extracts containing other divalent cations (manganese, iron, and copper) did not decrease the locomotor activity. This is the first evidence that zinc can induce sleep. Our data open the way to new types of food supplements designed to improve sleep. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impact of traumatic brain injury on sleep structure, electrocorticographic activity and transcriptome in mice.

PubMed

Sabir, Meriem; Gaudreault, Pierre-Olivier; Freyburger, Marlène; Massart, Renaud; Blanchet-Cohen, Alexis; Jaber, Manar; Gosselin, Nadia; Mongrain, Valérie

2015-07-01

Traumatic brain injury (TBI), including mild TBI (mTBI), is importantly associated with vigilance and sleep complaints. Because sleep is required for learning, plasticity and recovery, we here evaluated the bidirectional relationship between mTBI and sleep with two specific objectives: (1) Test that mTBI rapidly impairs sleep-wake architecture and the dynamics of the electrophysiological marker of sleep homeostasis (i.e., non-rapid eye movement sleep delta (1-4Hz) activity); (2) evaluate the impact of sleep loss following mTBI on the expression of plasticity markers that have been linked to sleep homeostasis and on genome-wide gene expression. A closed-head injury model was used to perform a 48h electrocorticographic (ECoG) recording in mice submitted to mTBI or Sham surgery. mTBI was found to immediately decrease the capacity to sustain long bouts of wakefulness as well as the amplitude of the time course of ECoG delta activity during wakefulness. Significant changes in ECoG spectral activity during wakefulness, non-rapid eye movement and rapid eye movement sleep were observed mainly on the second recorded day. A second experiment was performed to measure gene expression in the cerebral cortex and hippocampus after a mTBI followed either by two consecutive days of 6h sleep deprivation (SD) or of undisturbed behavior (quantitative PCR and next-generation sequencing). mTBI modified the expression of genes involved in immunity, inflammation and glial function (e.g., chemokines, glial markers) and SD changed that of genes linked to circadian rhythms, synaptic activity/neuronal plasticity, neuroprotection and cell death and survival. SD appeared to affect gene expression in the cerebral cortex more importantly after mTBI than Sham surgery including that of the astrocytic marker Gfap, which was proposed as a marker of clinical outcome after TBI. Interestingly, SD impacted the hippocampal expression of the plasticity elements Arc and EfnA3 only after mTBI. Overall, our findings reveal alterations in spectral signature across all vigilance states in the first days after mTBI, and show that sleep loss post-mTBI reprograms the transcriptome in a brain area-specific manner and in a way that could be deleterious to brain recovery. Copyright © 2015 Elsevier Inc. All rights reserved.

Recalling and forgetting dreams: theta and alpha oscillations during sleep predict subsequent dream recall.

PubMed

Marzano, Cristina; Ferrara, Michele; Mauro, Federica; Moroni, Fabio; Gorgoni, Maurizio; Tempesta, Daniela; Cipolli, Carlo; De Gennaro, Luigi

2011-05-04

Under the assumption that dream recall is a peculiar form of declarative memory, we have hypothesized that (1) the encoding of dream contents during sleep should share some electrophysiological mechanisms with the encoding of episodic memories of the awake brain and (2) recalling a dream(s) after awakening from non-rapid eye movement (NREM) and rapid eye movement (REM) sleep should be associated with different brain oscillations. Here, we report that cortical brain oscillations of human sleep are predictive of successful dream recall. In particular, after morning awakening from REM sleep, a higher frontal 5-7 Hz (theta) activity was associated with successful dream recall. This finding mirrors the increase in frontal theta activity during successful encoding of episodic memories in wakefulness. Moreover, in keeping with the different EEG background, a different predictive relationship was found after awakening from stage 2 NREM sleep. Specifically, a lower 8-12 Hz (alpha) oscillatory activity of the right temporal area was associated with a successful dream recall. These findings provide the first evidence of univocal cortical electroencephalographic correlates of dream recall, suggesting that the neurophysiological mechanisms underlying the encoding and recall of episodic memories may remain the same across different states of consciousness.

Disrupted rapid eye movement sleep predicts poor declarative memory performance in post-traumatic stress disorder.

PubMed

Lipinska, Malgorzata; Timol, Ridwana; Kaminer, Debra; Thomas, Kevin G F

2014-06-01

Successful memory consolidation during sleep depends on healthy slow-wave and rapid eye movement sleep, and on successful transition across sleep stages. In post-traumatic stress disorder, sleep is disrupted and memory is impaired, but relations between these two variables in the psychiatric condition remain unexplored. We examined whether disrupted sleep, and consequent disrupted memory consolidation, is a mechanism underlying declarative memory deficits in post-traumatic stress disorder. We recruited three matched groups of participants: post-traumatic stress disorder (n = 16); trauma-exposed non-post-traumatic stress disorder (n = 15); and healthy control (n = 14). They completed memory tasks before and after 8 h of sleep. We measured sleep variables using sleep-adapted electroencephalography. Post-traumatic stress disorder-diagnosed participants experienced significantly less sleep efficiency and rapid eye movement sleep percentage, and experienced more awakenings and wake percentage in the second half of the night than did participants in the other two groups. After sleep, post-traumatic stress disorder-diagnosed participants retained significantly less information on a declarative memory task than controls. Rapid eye movement percentage, wake percentage and sleep efficiency correlated with retention of information over the night. Furthermore, lower rapid eye movement percentage predicted poorer retention in post-traumatic stress disorder-diagnosed individuals. Our results suggest that declarative memory consolidation is disrupted during sleep in post-traumatic stress disorder. These data are consistent with theories suggesting that sleep benefits memory consolidation via predictable neurobiological mechanisms, and that rapid eye movement disruption is more than a symptom of post-traumatic stress disorder. © 2014 European Sleep Research Society.

Sleep-stage sequencing of sleep-onset REM periods in MSLT predicts treatment response in patients with narcolepsy.

PubMed

Drakatos, Panagis; Patel, Kishankumar; Thakrar, Chiraag; Williams, Adrian J; Kent, Brian D; Leschziner, Guy D

2016-04-01

Current treatment recommendations for narcolepsy suggest that modafinil should be used as a first-line treatment ahead of conventional stimulants or sodium oxybate. In this study, performed in a tertiary sleep disorders centre, treatment responses were examined following these recommendations, and the ability of sleep-stage sequencing of sleep-onset rapid eye movement periods in the multiple sleep latency test to predict treatment response. Over a 3.5-year period, 255 patients were retrospectively identified in the authors' database as patients diagnosed with narcolepsy, type 1 (with cataplexy) or type 2 (without) using clinical and polysomnographic criteria. Eligible patients were examined in detail, sleep study data were abstracted and sleep-stage sequencing of sleep-onset rapid eye movement periods were analysed. Response to treatment was graded utilizing an internally developed scale. Seventy-five patients were included (39% males). Forty (53%) were diagnosed with type 1 narcolepsy with a mean follow-up of 2.37 ± 1.35 years. Ninety-seven percent of the patients were initially started on modafinil, and overall 59% reported complete response on the last follow-up. Twenty-nine patients (39%) had the sequence of sleep stage 1 or wake to rapid eye movement in all of their sleep-onset rapid eye movement periods, with most of these diagnosed as narcolepsy type 1 (72%). The presence of this specific sleep-stage sequence in all sleep-onset rapid eye movement periods was associated with worse treatment response (P = 0.0023). Sleep-stage sequence analysis of sleep-onset rapid eye movement periods in the multiple sleep latency test may aid the prediction of treatment response in narcoleptics and provide a useful prognostic tool in clinical practice, above and beyond their classification as narcolepsy type 1 or 2. © 2015 European Sleep Research Society.

Sympathetic ophthalmia: incidence of ocular complications and vision loss in the sympathizing eye.

PubMed

Galor, Anat; Davis, Janet L; Flynn, Harry W; Feuer, William J; Dubovy, Sander R; Setlur, Vikram; Kesen, Muge R; Goldstein, Debra A; Tessler, Howard H; Ganelis, Irina Bykhovskaya; Jabs, Douglas A; Thorne, Jennifer E

2009-11-01

To report the frequency on presentation and subsequent incidence of ocular complications and vision loss in patients with sympathetic ophthalmia (SO) and to describe factors associated with decreased vision in the sympathizing eye. Multicenter retrospective case series. Three academic tertiary care uveitis clinics. Eighty-five patients with SO from 1976 to 2006. Review of existing medical records. Incident visual acuity (VA) loss to 20/50 or worse and 20/200 or worse and the median acuity over time. Twenty-six percent of patients with SO presented with a VA of 20/200 or worse in their sympathizing eye. Further development of vision loss to 20/200 or worse occurred at the rate of 10% per person-year (PY). Ocular complications were seen in the sympathizing eye in 47% of patients at presentation; further development of new complications occurred at the rate of 40%/PY. The ocular complications most often associated with decreased vision were cataract and optic nerve abnormality. Exudative retinal detachment and active intraocular inflammation were significantly associated with poorer VA in the sympathizing eye. The benefits of corticosteroids were indirectly demonstrated as their use led to more rapid disease inactivation. Fifty-nine percent of patients maintained a VA of better than 20/50 in their sympathizing eye; and 75% maintained a VA of better than 20/200. Although ocular complications were seen in many sympathizing eyes with SO, most patients maintained functional VA. The presence of an exudative retinal detachment and active intraocular inflammation correlated with poorer vision in the sympathizing eye.

Metabolic Mapping of the Brain's Response to Visual Stimulation: Studies in Humans.

ERIC Educational Resources Information Center

Phelps, Michael E.; Kuhl, David E.

1981-01-01

Studies demonstrate increasing glucose metabolic rates in human primary (PVC) and association (AVC) visual cortex as complexity of visual scenes increase. AVC increased more rapidly with scene complexity than PVC and increased local metabolic activities above control subject with eyes closed; indicates wide range and metabolic reserve of visual…

[Recent progress of neuroimaging studies on sleeping brain].

PubMed

Sasaki, Yuka

2012-06-01

Although sleep is a familiar phenomenon, its functions are yet to be elucidated. Understanding these functions of sleep is an important focus area in neuroscience. Electroencephalography (EEG) has been the predominantly used method in human sleep research but does not provide detailed spatial information about brain activation during sleep. To supplement the spatial information provided by this method, researchers have started using a combination of EEG and various advanced neuroimaging techniques that have been recently developed, including positron emission tomography (PET) and magnetic resonance imaging (MRI). In this paper, we will review the recent progress in sleep studies, especially studies that have used such advanced neuroimaging techniques. First, we will briefly introduce several neuroimaging techniques available for use in sleep studies. Next, we will review the spatiotemporal brain activation patterns during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, the dynamics of functional connectivity during sleep, and the consolidation of learning and memory during sleep; studies on the neural correlates of dreams, which have not yet been identified, will also be discussed. Lastly, possible directions for future research in this area will be discussed.

Sleep/wake dependent changes in cortical glucose concentrations.

PubMed

Dash, Michael B; Bellesi, Michele; Tononi, Giulio; Cirelli, Chiara

2013-01-01

Most of the energy in the brain comes from glucose and supports glutamatergic activity. The firing rate of cortical glutamatergic neurons, as well as cortical extracellular glutamate levels, increase with time spent awake and decline throughout non rapid eye movement sleep, raising the question whether glucose levels reflect behavioral state and sleep/wake history. Here chronic (2-3 days) electroencephalographic recordings in the rat cerebral cortex were coupled with fixed-potential amperometry to monitor the extracellular concentration of glucose ([gluc]) on a second-by-second basis across the spontaneous sleep-wake cycle and in response to 3 h of sleep deprivation. [Gluc] progressively increased during non rapid eye movement sleep and declined during rapid eye movement sleep, while during wake an early decline in [gluc] was followed by an increase 8-15 min after awakening. There was a significant time of day effect during the dark phase, when rats are mostly awake, with [gluc] being significantly lower during the last 3-4 h of the night relative to the first 3-4 h. Moreover, the duration of the early phase of [gluc] decline during wake was longer after prolonged wake than after consolidated sleep. Thus, the sleep/wake history may affect the levels of glucose available to the brain upon awakening. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Spasmus nutans

MedlinePlus

... infants and young children. It involves rapid, uncontrolled eye movements, head bobbing, and, sometimes, holding the neck in ... spasmus nutans include: Small, quick, side-to-side eye movements called nystagmus (both eyes are involved, but each ...

Extraocular muscle function testing

MedlinePlus

... may result in double vision or rapid, uncontrolled eye movements . Normal Results Normal movement of the eyes in all directions. What Abnormal Results Mean Eye movement disorders may be due to abnormalities of the ...

Acute enhancement of non-rapid eye movement sleep in rats after drinking water contaminated with cadmium chloride.

PubMed

Unno, Katsuya; Yamoto, Kurumi; Takeuchi, Kouhei; Kataoka, Aya; Ozaki, Tomoya; Mochizuki, Takatoshi; Honda, Kazuki; Miura, Nobuhiko; Ikeda, Masayuki

2014-02-01

Cadmium (Cd) is a heavy metal widely used or effused by industries. Serious environmental Cd pollution has been reported over the past two centuries, whereas the mechanisms underlying Cd-mediated diseases are not fully understood. Interestingly, an increase in reactive oxygen species (ROS) after Cd exposure has been shown. Our group has demonstrated that sleep is triggered via accumulation of ROS during neuronal activities, and we thus hypothesize the involvement of Cd poisoning in sleep-wake irregularities. In the present study, we analyzed the effects of Cd intake (1-100 ppm CdCl₂ in drinking water) on rats by monitoring sleep encephalograms and locomotor activities. The results demonstrated that 100 ppm CdCl₂ administration for 28 h was sufficient to increase non-rapid-eye-movement (non-REM) sleep and reduce locomotor activities during the night (the rat active phase). In contrast, free-running locomotor rhythms under constant dim red light and their re-entrainment to 12:12-h light/dark cycles were intact under chronic (1 month) 100 ppm CdCl₂ administrations, suggesting a limited influence on circadian clock movements at this dosage. The relative amount of oxidized glutathione increased in the brain after the 28-h 100 ppm CdCl₂ administrations similar to the levels in cultured astrocytes receiving H₂O₂ or CdCl₂ in culture medium. Therefore, we propose Cd-induced sleep as a consequence of oxidative stress. As oxidized glutathione is an endogenous sleep substance, we suggest that Cd rapidly induces sleepiness and influences activity performance by occupying intrinsic sleep-inducing mechanisms. In conclusion, we propose increased non-REM sleep during the active phase as an index of acute Cd exposure. Copyright © 2013 John Wiley & Sons, Ltd.

Rapid regulation of brain-derived neurotrophic factor mRNA within eye-specific circuits during ocular dominance column formation.

PubMed

Lein, E S; Shatz, C J

2000-02-15

The neurotrophin brain-derived neurotrophic factor (BDNF) has emerged as a candidate retrograde signaling molecule for geniculocortical axons during the formation of ocular dominance columns. Here we examined whether neuronal activity can regulate BDNF mRNA in eye-specific circuits in the developing cat visual system. Dark-rearing throughout the critical period for ocular dominance column formation decreases levels of BDNF mRNA within primary visual cortex, whereas short-term (2 d) binocular blockade of retinal activity with tetrodotoxin (TTX) downregulates BDNF mRNA within the lateral geniculate nucleus (LGN) and visual cortical areas. Brief (6 hr to 2 d) monocular TTX blockade during the critical period and also in adulthood causes downregulation in appropriate eye-specific laminae in the LGN and ocular dominance columns within primary visual cortex. Monocular TTX blockade at postnatal day 23 also downregulates BDNF mRNA in a periodic fashion, consistent with recent observations that ocular dominance columns can be detected at these early ages by physiological methods. In contrast, 10 d monocular TTX during the critical period does not cause a lasting decrease in BDNF mRNA expression in columns pertaining to the treated eye, consistent with the nearly complete shift in physiological response properties of cortical neurons in favor of the unmanipulated eye known to result from long-term monocular deprivation. These observations demonstrate that BDNF mRNA levels can provide an accurate "molecular readout" of the activity levels of cortical neurons and are consistent with a highly local action of BDNF in strengthening and maintaining active synapses during ocular dominance column formation.

Postural Effects on Pharyngeal Protective Reflex Mechanisms

PubMed Central

Malhotra, Atul; Trinder, John; Fogel, Robert; Stanchina, Michael; Patel, Sanjay R.; Schory, Karen; Kleverlaan, Darci; White, David P.

2012-01-01

Study Objectives Pharyngeal muscle dilators are important in obstructive sleep apnea pathogenesis because the failure of protective reflexes involving these muscles yields pharyngeal collapse. Conflicting results exist in the literature regarding the responsiveness of these muscles during stable non-rapid eye movement sleep. However, variations in posture in previous studies may have influenced these findings. We hypothesized that tongue protruder muscles are maximally responsive to negative pressure pulses during supine sleep, when posterior tongue displacement yields pharyngeal occlusion. Design We studied all subjects in the supine and lateral postures during wakefulness and stable non-rapid eye movement sleep by measuring genioglossus and tensor palatini electromyograms during basal breathing and following negative pressure pulses. Setting Upper-airway physiology laboratory of Sleep Medicine Division, Brigham and Women’s Hospital. Subjects/Participants 17 normal subjects. Measurements and Results We observed an increase in genioglossal responsiveness to negative pressure pulses in sleep as compared to wakefulness in supine subjects (3.9 percentage of maximum [%max] ± 1.1 vs 4.4 %max ± 1.0) but a decrease in the lateral decubitus position (4.1 %max ± 1.0 vs 1.5 %max ± 0.4), the interaction effect being significant. Despite this augmented reflex, collapsibility, as measured during negative pressure pulses, increased more while subjects were in the supine position as compared with the lateral decubitus position. While the interaction between wake-sleep state and position was also significant for the tensor palatini, the effect was weaker than for genioglossus, although, for tensor palatini, baseline activity was markedly reduced during non-rapid eye movement sleep as compared with wakefulness. Conclusions We conclude that body posture does have an important impact on genioglossal responsiveness to negative pressure pulses during non-rapid eye movement sleep. We speculate that this mechanism works to prevent pharyngeal occlusion when the upper airway is most vulnerable to collapse eg, during supine sleep. PMID:15532204

CONTROL OF SLEEP AND WAKEFULNESS

PubMed Central

Brown, Ritchie E.; Basheer, Radhika; McKenna, James T.; Strecker, Robert E.; McCarley, Robert W.

2013-01-01

This review summarizes the brain mechanisms controlling sleep and wakefulness. Wakefulness promoting systems cause low-voltage, fast activity in the electroencephalogram (EEG). Multiple interacting neurotransmitter systems in the brain stem, hypothalamus, and basal forebrain converge onto common effector systems in the thalamus and cortex. Sleep results from the inhibition of wake-promoting systems by homeostatic sleep factors such as adenosine and nitric oxide and GABAergic neurons in the preoptic area of the hypothalamus, resulting in large-amplitude, slow EEG oscillations. Local, activity-dependent factors modulate the amplitude and frequency of cortical slow oscillations. Non-rapid-eye-movement (NREM) sleep results in conservation of brain energy and facilitates memory consolidation through the modulation of synaptic weights. Rapid-eye-movement (REM) sleep results from the interaction of brain stem cholinergic, aminergic, and GABAergic neurons which control the activity of glutamatergic reticular formation neurons leading to REM sleep phenomena such as muscle atonia, REMs, dreaming, and cortical activation. Strong activation of limbic regions during REM sleep suggests a role in regulation of emotion. Genetic studies suggest that brain mechanisms controlling waking and NREM sleep are strongly conserved throughout evolution, underscoring their enormous importance for brain function. Sleep disruption interferes with the normal restorative functions of NREM and REM sleep, resulting in disruptions of breathing and cardiovascular function, changes in emotional reactivity, and cognitive impairments in attention, memory, and decision making. PMID:22811426

Mice Lacking Alternatively Activated (M2) Macrophages Show Impairments in Restorative Sleep after Sleep Loss and in Cold Environment.

PubMed

Massie, Ashley; Boland, Erin; Kapás, Levente; Szentirmai, Éva

2018-06-05

The relationship between sleep, metabolism and immune functions has been described, but the cellular components of the interaction are incompletely identified. We previously reported that systemic macrophage depletion results in sleep impairment after sleep loss and in cold environment. These findings point to the role of macrophage-derived signals in maintaining normal sleep. Macrophages exist either in resting form, classically activated, pro-inflammatory (M1) or alternatively activated, anti-inflammatory (M2) phenotypes. In the present study we determined the contribution of M2 macrophages to sleep signaling by using IL-4 receptor α-chain-deficient [IL-4Rα knockout (KO)] mice, which are unable to produce M2 macrophages. Sleep deprivation induced robust increases in non-rapid-eye-movement sleep (NREMS) and slow-wave activity in wild-type (WT) animals. NREMS rebound after sleep deprivation was ~50% less in IL-4Rα KO mice. Cold exposure induced reductions in rapid-eye-movement sleep (REMS) and NREMS in both WT and KO mice. These differences were augmented in IL-4Rα KO mice, which lost ~100% more NREMS and ~25% more REMS compared to WTs. Our finding that M2 macrophage-deficient mice have the same sleep phenotype as mice with global macrophage depletion reconfirms the significance of macrophages in sleep regulation and suggests that the main contributors are the alternatively activated M2 cells.

Quantitative assessment of isolated rapid eye movement (REM) sleep without atonia without clinical REM sleep behavior disorder: clinical and research implications.

PubMed

Sasai-Sakuma, Taeko; Frauscher, Birgit; Mitterling, Thomas; Ehrmann, Laura; Gabelia, David; Brandauer, Elisabeth; Inoue, Yuichi; Poewe, Werner; Högl, Birgit

2014-09-01

Rapid eye movement (REM) sleep without atonia (RWA) is observed in some patients without a clinical history of REM sleep behavior disorder (RBD). It remains unknown whether these patients meet the refined quantitative electromyographic (EMG) criteria supporting a clinical RBD diagnosis. We quantitatively evaluated EMG activity and investigated its overnight distribution in patients with isolated qualitative RWA. Fifty participants with an incidental polysomnographic finding of RWA (isolated qualitative RWA) were included. Tonic, phasic, and 'any' EMG activity during REM sleep on PSG were quantified retrospectively. Referring to the quantitative cut-off values for a polysomnographic diagnosis of RBD, 7/50 (14%) and 6/50 (12%) of the patients showed phasic and 'any' EMG activity in the mentalis muscle above the respective cut-off values. No patient was above the cut-off value for tonic EMG activity or phasic EMG activity in the anterior tibialis muscles. Patients with RWA above the cut-off value showed higher amounts of RWA during later REM sleep periods. This is the first study showing that some subjects with incidental RWA meet the refined quantitative EMG criteria for a diagnosis of RBD. Future longitudinal studies must investigate whether this subgroup with isolated qualitative RWA is at an increased risk of developing fully expressed RBD and/or neurodegenerative disease. Copyright © 2014 Elsevier B.V. All rights reserved.

Mucoadhesive Microparticles in a Rapidly Dissolving Tablet for Sustained Drug Delivery to the Eye

PubMed Central

Choy, Young Bin; Patel, Samirkumar R.; Park, Jung-Hwan; McCarey, Bernard E.; Edelhauser, Henry F.

2011-01-01

Purpose. To test the hypothesis that mucoadhesive microparticles formulated in a rapidly dissolving tablet can achieve sustained drug delivery to the eye. Methods. Mucoadhesive microparticles, smaller than 5 μm were fabricated with poly(lactic-co-glycolic acid) and poly(ethylene glycol) as a core material and mucoadhesion promoter, respectively, and encapsulated pilocarpine as a model drug. These microparticles were embedded in a poly(vinyl alcohol) matrix to form a dry tablet designed to reduce rapid clearance of the microparticles on initial application to the eye. Results. This in vitro drug release study exhibited that for all formulations, approximately 90% of pilocarpine was released during the first 10 minutes, and the remaining 10% was released slowly for 3 hours. In vivo mucoadhesion test on the rabbit eye indicated that mucoadhesive microparticles adhered significantly better to the preocular surface than other formulations. To assess the pharmacodynamics, the most prolonged pilocarpine-induced pupil constriction was observed in rabbit eyes in vivo using a tablet with mucoadhesive microparticles; it lasted up to 330 minutes. Conclusions. The authors conclude that mucoadhesive microparticles formulated into a dry dosage form is a promising system for sustained drug delivery to the eye. PMID:21245405

Respiratory-related activity in hypoglossal neurons across sleep-waking states in cats.

PubMed

Richard, C A; Harper, R M

1991-02-22

Activity of behaviorally identified neurons in the hypoglossal nuclei supplying the genioglossal muscles was assessed in intact, unanesthetized cats across sleep-wake states. Nineteen of 37 recorded cells discharged on a breath-by-breath or tonic basis with the respiratory cycle in at least one state. Most respiratory-related cells discharged more slowly during quiet sleep, whereas rates during rapid eye movement sleep were similar to those of waking.

Ventromedial prefrontal cortex activity and rapid eye movement sleep are associated with subsequent fear expression in human subjects.

PubMed

Spoormaker, V I; Gvozdanovic, G A; Sämann, P G; Czisch, M

2014-05-01

In humans, activity patterns in the ventromedial prefrontal cortex (vmPFC) have been found to be predictive of subsequent fear memory consolidation. Pioneering work in rodents has further shown that vmPFC-amygdala theta synchronization is correlated with fear memory consolidation. We aimed to evaluate whether vmPFC activity during fear conditioning is (1) correlated with fear expression the subsequent day and whether (2) this relationship is mediated by rapid eye movement (REM) sleep. We analyzed data from 17 young healthy subjects undergoing a fear conditioning task, followed by a fear extinction task 24 h later, both recorded with simultaneous skin conductance response (SCR) and functional magnetic resonance imaging measurements, with a polysomnographically recorded night sleep in between. Our results showed a correlation between vmPFC activity during fear conditioning and subsequent REM sleep amount, as well as between REM sleep amount and SCR to the conditioned stimulus 24 h later. Moreover, we observed a significant correlation between vmPFC activity during fear conditioning and SCR responses during extinction, which was no longer significant after controlling for REM sleep amount. vmPFC activity during fear conditioning was further correlated with sleep latency. Interestingly, hippocampus activity during fear conditioning was correlated with stage 2 and stage 4 sleep amount. Our results provide preliminary evidence that the relationship between REM sleep and fear conditioning and extinction observed in rodents can be modeled in healthy human subjects, highlighting an interrelated set of potentially relevant trait markers.

Trained Eyes: Experience Promotes Adaptive Gaze Control in Dynamic and Uncertain Visual Environments

PubMed Central

Taya, Shuichiro; Windridge, David; Osman, Magda

2013-01-01

Current eye-tracking research suggests that our eyes make anticipatory movements to a location that is relevant for a forthcoming task. Moreover, there is evidence to suggest that with more practice anticipatory gaze control can improve. However, these findings are largely limited to situations where participants are actively engaged in a task. We ask: does experience modulate anticipative gaze control while passively observing a visual scene? To tackle this we tested people with varying degrees of experience of tennis, in order to uncover potential associations between experience and eye movement behaviour while they watched tennis videos. The number, size, and accuracy of saccades (rapid eye-movements) made around ‘events,’ which is critical for the scene context (i.e. hit and bounce) were analysed. Overall, we found that experience improved anticipatory eye-movements while watching tennis clips. In general, those with extensive experience showed greater accuracy of saccades to upcoming event locations; this was particularly prevalent for events in the scene that carried high uncertainty (i.e. ball bounces). The results indicate that, even when passively observing, our gaze control system utilizes prior relevant knowledge in order to anticipate upcoming uncertain event locations. PMID:23951147

Pramipexole in the treatment of REM sleep behaviour disorder: A critical review.

PubMed

Tan, Shian Ming; Wan, Yi Min

2016-09-30

While widely accepted as a first-line treatment for rapid eye movement sleep (REM) behaviour disorder, clonazepam (CNZP) has side effects that limit its applicability. Pramipexole is a possible alternative, but limited literature on its effectiveness exists. This review aims to summarize the available data on the use of pramipexole in REM sleep behaviour disorder. A systematic search of major databases was conducted to look for published and on-going trials. This search yielded a total of five articles, all of which are observational in nature. Factors associated with effectiveness include low doses (less than 1.5mg/day) and idiopathic rapid eye movement sleep behaviour disorder/absence of neurodegenerative disease. Overall, the evidence is inconclusive. This is due to the lack of randomised controlled trials and the challenges in interpreting polysomgraphy findings in rapid eye movement sleep behaviour disorder. Suggestions are given on how future trials evaluating pramipexole treatment in rapid eye movement sleep behaviour disorder could overcome current methodological issues in extant literature. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Development and validation of an algorithm for the study of sleep using a biometric shirt in young healthy adults.

PubMed

Pion-Massicotte, Joëlle; Godbout, Roger; Savard, Pierre; Roy, Jean-François

2018-02-23

Portable polysomnography is often too complex and encumbering for recording sleep at home. We recorded sleep using a biometric shirt (electrocardiogram sensors, respiratory inductance plethysmography bands and an accelerometer) in 21 healthy young adults recorded in a sleep laboratory for two consecutive nights, together with standard polysomnography. Polysomnographic recordings were scored using standard methods. An algorithm was developed to classify the biometric shirt recordings into rapid eye movement sleep, non-rapid eye movement sleep and wake. The algorithm was based on breathing rate and heart rate variability, body movement, and included a correction for sleep onset and offset. The overall mean percentage of agreement between the two sets of recordings was 77.4%; when non-rapid eye movement and rapid eye movement sleep epochs were grouped together, it increased to 90.8%. The overall kappa coefficient was 0.53. Five of the seven sleep variables were significantly correlated. The findings of this pilot study indicate that this simple portable system could be used to estimate the general sleep pattern of young healthy adults. © 2018 European Sleep Research Society.

Improvement of a rapid screening test for chronic granulomatous disease.

PubMed

Iacobini, M; Duse, M; Di Coste, A; Balducci, L

2013-01-01

Diagnosis of CGD is made by demonstrating absent or markedly reduced oxidase activity in stimulated neutrophils. The screening test proposed is based upon the naked eye evaluation of the reduction of NBT on a solid surface. It seems to be a useful tool for rapid and inexpensive detection of CGD patients, especially for large-scale screening purposes. The test was carried out on forty-five subjects: two males affected by CGD, three female carriers and forty healthy donors. The test confirmed the results obtained with flow cytometric and NBT assays.

Rapid corneal thinning and perforated ulcerative keratitis in a patient with relapsing polychondritis.

PubMed

Lai, Tracy Hiu Ting; Far, Nikki; Young, Alvin Lerrmann; Jhanji, Vishal

2017-01-01

To report rapid corneal thinning and perforation in a case with relapsing polychondritis. A 43 year-old male diagnosed with relapsing polychondritis suffered from bilateral scleritis, bilateral swelling of pinna, saddle nose and tracheal stenosis. The patient presented with right eye pain and redness for one month. Slit lamp examination of the right eye showed 80% peripheral corneal thinning between 3 and 7 o'clock. The best-corrected visual acuity (BCVA) was 1.0 bilaterally. The degree of corneal thinning worsened to 90% after one week of oral corticosteroid use. Subsequently, topical cyclosporine 2% eye drops four times a day, oral doxycycline 100 mg twice a day and oral vitamin C 2 g daily were added. The corneal thinning gradually improved to about 60%. However, the patient rapidly tapered oral prednisolone against medical advice and returned with an acute drop in vision in his right eye. Slit lamp examination of the right eye showed peripheral corneal perforation with iris prolapse. An emergency repair with cyanoacrylate glue was performed. Intravenous methylprednisolone 1 mg/kg body weight was administered for three days and 1 g/day intravenous immunoglobulin was administered every four weeks. At 3 months postoperatively, BCVA in the right eye was 0.6. Slit lamp examination showed a well-formed anterior chamber with glue in situ. Relapsing polychondritis may be associated with rapid corneal thinning. The clinicians should be aware of the possibility of corneal perforation in these cases. Cyanoacrylate glue is a viable temporary management option in such scenarios.

Rapid eye movement sleep does not seem to unbind memories from their emotional context.

PubMed

Deliens, Gaétane; Neu, Daniel; Peigneux, Philippe

2013-12-01

Sleep unbinds memories from their emotional learning context, protecting them from emotional interference due to a change of mood between learning and recall. According to the 'sleep to forget and sleep to remember' model, emotional unbinding takes place during rapid eye movement sleep. To test this hypothesis, we investigated emotional contextual interference effects after early versus late post-learning sleep periods, in which slow wave and rapid eye movement sleep, respectively, predominate. Participants learned a list of neutral word pairs after induction of a happy or a sad mood, then slept immediately afterwards for 3 h of early or late sleep under polysomnographic recording, in a within-subject counterbalanced design. They slept for 3 h before learning in the late sleep condition. Polysomnographic data confirmed more rapid eye movement sleep in the late than in the early sleep condition. After awakening, half the list was recalled after induction of a similar mood than during the encoding session (non-interference condition), and the other half of the list was recalled after induction of a different mood (interference condition). The results disclosed an emotional interference effect on recall both in the early and late sleep conditions, which does not corroborate the hypothesis of a rapid eye movement sleep-related protection of recent memories from emotional contextual interference. Alternatively, the contextual demodulation process initiated during the first post-learning night might need several consecutive nights of sleep to be achieved. © 2013 European Sleep Research Society.

Facilitation of epileptic activity during sleep is mediated by high amplitude slow waves

PubMed Central

von Ellenrieder, Nicolás; Ferrari-Marinho, Taissa; Avoli, Massimo; Dubeau, François; Gotman, Jean

2015-01-01

Epileptic discharges in focal epilepsy are frequently activated during non-rapid eye movement sleep. Sleep slow waves are present during this stage and have been shown to include a deactivated (‘down’, hyperpolarized) and an activated state (‘up’, depolarized). The ‘up’ state enhances physiological rhythms, and we hypothesize that sleep slow waves and particularly the ‘up’ state are the specific components of non-rapid eye movement sleep that mediate the activation of epileptic activity. We investigated eight patients with pharmaco-resistant focal epilepsies who underwent combined scalp-intracerebral electroencephalography for diagnostic evaluation. We analysed 259 frontal electroencephalographic channels, and manually marked 442 epileptic spikes and 8487 high frequency oscillations during high amplitude widespread slow waves, and during matched control segments with low amplitude widespread slow waves, non-widespread slow waves or no slow waves selected during the same sleep stages (total duration of slow wave and control segments: 49 min each). During the slow waves, spikes and high frequency oscillations were more frequent than during control segments (79% of spikes during slow waves and 65% of high frequency oscillations, both P ∼ 0). The spike and high frequency oscillation density also increased for higher amplitude slow waves. We compared the density of spikes and high frequency oscillations between the ‘up’ and ‘down’ states. Spike and high frequency oscillation density was highest during the transition from the ‘up’ to the ‘down’ state. Interestingly, high frequency oscillations in channels with normal activity expressed a different peak at the transition from the ‘down’ to the ‘up’ state. These results show that the apparent activation of epileptic discharges by non-rapid eye movement sleep is not a state-dependent phenomenon but is predominantly associated with specific events, the high amplitude widespread slow waves that are frequent, but not continuous, during this state of sleep. Both epileptic spikes and high frequency oscillations do not predominate, like physiological activity, during the ‘up’ state but during the transition from the ‘up’ to the ‘down’ state of the slow wave, a period of high synchronization. Epileptic discharges appear therefore more associated with synchronization than with excitability. Furthermore, high frequency oscillations in channels devoid of epileptic activity peak differently during the slow wave cycle from those in channels with epileptic activity. This property may allow differentiating physiological from pathological high frequency oscillations, a problem that is unresolved until now. PMID:25792528

Sex differences in objective measures of sleep in post-traumatic stress disorder and healthy control subjects.

PubMed

Richards, Anne; Metzler, Thomas J; Ruoff, Leslie M; Inslicht, Sabra S; Rao, Madhu; Talbot, Lisa S; Neylan, Thomas C

2013-12-01

A growing literature shows prominent sex effects for risk for post-traumatic stress disorder and associated medical comorbid burden. Previous research indicates that post-traumatic stress disorder is associated with reduced slow wave sleep, which may have implications for overall health, and abnormalities in rapid eye movement sleep, which have been implicated in specific post-traumatic stress disorder symptoms, but most research has been conducted in male subjects. We therefore sought to compare objective measures of sleep in male and female post-traumatic stress disorder subjects with age- and sex-matched control subjects. We used a cross-sectional, 2 × 2 design (post-traumatic stress disorder/control × female/male) involving83 medically healthy, non-medicated adults aged 19-39 years in the inpatient sleep laboratory. Visual electroencephalographic analysis demonstrated that post-traumatic stress disorder was associated with lower slow wave sleep duration (F(3,82)  = 7.63, P = 0.007) and slow wave sleep percentage (F(3,82)  = 6.11, P = 0.016). There was also a group × sex interaction effect for rapid eye movement sleep duration (F(3,82)  = 4.08, P = 0.047) and rapid eye movement sleep percentage (F(3,82)  = 4.30, P = 0.041), explained by greater rapid eye movement sleep in post-traumatic stress disorder females compared to control females, a difference not seen in male subjects. Quantitative electroencephalography analysis demonstrated that post-traumatic stress disorder was associated with lower energy in the delta spectrum (F(3,82)  = 6.79, P = 0.011) in non-rapid eye movement sleep. Slow wave sleep and delta findings were more pronounced in males. Removal of post-traumatic stress disorder subjects with comorbid major depressive disorder, who had greater post-traumatic stress disorder severity, strengthened delta effects but reduced rapid eye movement effects to non-significance. These findings support previous evidence that post-traumatic stress disorder is associated with impairment in the homeostatic function of sleep, especially in men with the disorder. These findings suggest that group × sex interaction effects on rapid eye movement may occur with more severe post-traumatic stress disorder or with post-traumatic stress disorder comorbid with major depressive disorder. © 2013 European Sleep Research Society.

Brain stem omnipause neurons and the control of combined eye-head gaze saccades in the alert cat.

PubMed

Paré, M; Guitton, D

1998-06-01

When the head is unrestrained, rapid displacements of the visual axis-gaze shifts (eye-re-space)-are made by coordinated movements of the eyes (eye-re-head) and head (head-re-space). To address the problem of the neural control of gaze shifts, we studied and contrasted the discharges of omnipause neurons (OPNs) during a variety of combined eye-head gaze shifts and head-fixed eye saccades executed by alert cats. OPNs discharged tonically during intersaccadic intervals and at a reduced level during slow perisaccadic gaze movements sometimes accompanying saccades. Their activity ceased for the duration of the saccadic gaze shifts the animal executed, either by head-fixed eye saccades alone or by combined eye-head movements. This was true for all types of gaze shifts studied: active movements to visual targets; passive movements induced by whole-body rotation or by head rotation about stationary body; and electrically evoked movements by stimulation of the caudal part of the superior colliculus (SC), a central structure for gaze control. For combined eye-head gaze shifts, the OPN pause was therefore not correlated to the eye-in-head trajectory. For instance, in active gaze movements, the end of the pause was better correlated with the gaze end than with either the eye saccade end or the time of eye counterrotation. The hypothesis that cat OPNs participate in controlling gaze shifts is supported by these results, and also by the observation that the movements of both the eyes and the head were transiently interrupted by stimulation of OPNs during gaze shifts. However, we found that the OPN pause could be dissociated from the gaze-motor-error signal producing the gaze shift. First, OPNs resumed discharging when perturbation of head motion briefly interrupted a gaze shift before its intended amplitude was attained. Second, stimulation of caudal SC sites in head-free cat elicited large head-free gaze shifts consistent with the creation of a large gaze-motor-error signal. However, stimulation of the same sites in head-fixed cat produced small "goal-directed" eye saccades, and OPNs paused only for the duration of the latter; neither a pause nor an eye movement occurred when the same stimulation was applied with the eyes at the goal location. We conclude that OPNs can be controlled by neither a simple eye control system nor an absolute gaze control system. Our data cannot be accounted for by existing models describing the control of combined eye-head gaze shifts and therefore put new constraints on future models, which will have to incorporate all the various signals that act synergistically to control gaze shifts.

β oscillation during slow wave sleep and rapid eye movement sleep in the electroencephalogram of a transgenic mouse model of Huntington's disease.

PubMed

Jeantet, Yannick; Cayzac, Sebastien; Cho, Yoon H

2013-01-01

To search for early abnormalities in electroencephalogram (EEG) during sleep which may precede motor symptoms in a transgenic mouse model of hereditary neurodegenerative Huntington's disease (HD). In the R6/1 transgenic mouse model of HD, rhythmic brain activity in EEG recordings was monitored longitudinally and across vigilance states through the onset and progression of disease. Mice with chronic electrode implants were recorded monthly over wake-sleep cycles (4 hours), beginning at 9-11 weeks (presymptomatic period) through 6-7 months (symptomatic period). Recording data revealed a unique β rhythm (20-35 Hz), present only in R6/1 transgenic mice, which evolves in close parallel with the disease. In addition, there was an unusual relationship between this β oscillation and vigilance states: while nearly absent during the active waking state, the β oscillation appeared with drowsiness and during slow wave sleep (SWS) and, interestingly, strengthened rather than dissipating when the brain returned to an activated state during rapid eye movement (REM) sleep. In addition to providing a new in vivo biomarker and insight into Huntington's disease pathophysiology, this serendipitous observation opens a window onto the rarely explored neurophysiology of the cortico-basal ganglia circuit during SWS and REM sleep.

Tumor Necrosis Factor Antagonism Normalizes Rapid Eye Movement Sleep in Alcohol Dependence

PubMed Central

Irwin, Michael R.; Olmstead, Richard; Valladares, Edwin M.; Breen, Elizabeth Crabb; Ehlers, Cindy L.

2009-01-01

Background In alcohol dependence, markers of inflammation are associated with increases in rapid eye movement (REM) sleep, which is thought to be a prognostic indicator of alcohol relapse. This study was undertaken to test whether blockade of biologically active tumor necrosis factor-α (TNF-α) normalizes REM sleep in alcohol-dependent adults. Methods In a randomized, placebo-controlled, double-blind, crossover trial, 18 abstinent alcohol-dependent male adults received a single dose of etanercept (25 mg) versus placebo in a counterbalanced order. Polysomnographic sleep was measured at baseline and for 3 nights after the acute dose of etanercept or placebo. Results Compared with placebo, administration of etanercept produced significant decreases in the amount and percentage of REM sleep. Decreases in REM sleep were robust and approached low levels typically found in age-comparable control subjects. Individual differences in biologically active drug as indexed by circulating levels of soluble tumor necrosis factor receptor II negatively correlated with the percentage of REM sleep. Conclusions Pharmacologic neutralization of TNF-α activity is associated with significant reductions in REM sleep in abstinent alcohol-dependent patients. These data suggest that circulating levels of TNF-α may have a physiologic role in the regulation of REM sleep in humans. PMID:19185287

Choline acetyltransferase expression during periods of behavioral activity and across natural sleep-wake states in the basal forebrain.

PubMed

Greco, M A; McCarley, R W; Shiromani, P J

1999-01-01

The present study examined whether the expression of the messenger RNA encoding the protein responsible for acetylcholine synthesis is associated with sleep-wakefulness. Choline acetyltransferase messenger RNA levels were analysed using a semi-quantitative assay in which reverse transcription was coupled to complementary DNA amplification using the polymerase chain reaction. To examine the relationship between steady-state messenger RNA and behavioral activity, rats were killed during the day (4.00 p.m.) or night (4.00 a.m.), and tissue from the vertical and horizontal limbs of the diagonal bands of Broca was analysed. Choline acetyltransferase messenger RNA levels were higher during the day than during the night. The second study examined more closely the association between choline acetyltransferase messenger RNA levels and individual bouts of wakefulness, slow-wave sleep or rapid eye movement sleep. Choline acetyltransferase messenger RNA levels were low during wakefulness, intermediate in slow-wave sleep and high during rapid eye movement sleep. In contrast, protein activity, measured at a projection site of cholinergic neurons of the basal forebrain, was higher during wakefulness than during sleep. These findings suggest that choline acetyltransferase protein and messenger RNA levels exhibit an inverse relationship during sleep and wakefulness. The increased messenger RNA expression during sleep is consistent with a restorative function of sleep.

The correlation between subordinate fish eye colour and received attacks: a negative social feedback mechanism for the reduction of aggression during the formation of dominance hierarchies.

PubMed

Miyai, Caio A; Carretero Sanches, Fábio H; Costa, Tânia M; Colpo, Karine Delevati; Volpato, Gilson L; Barreto, Rodrigo E

2011-12-01

Eye darkening has been linked to social status in fish. The subordinate's eyes darken, while the eyes of the dominant fish become pale. Although this phenomenon has been described in salmonid fishes and in the African cichlid Nile tilapia Oreochromis niloticus, it is unclear whether eye darkening correlates with a reduction in aggressive behaviour. Thus, we evaluated the link between social status and eye darkening. We evaluated whether the eye colours of subordinate fish correlate with the frequency of received attacks in a neotropical fish, the pearl cichlid Geophagus brasiliensis. We paired pearl cichlids and quantified both the aggressive behaviour and the eye darkening of each fish. As has been described for Nile tilapia and Atlantic salmon, a clear-cut hierarchical relationship formed, where dominance and subordination were associated with pale and dark eye colours, respectively. Initially, eye colour darkening was positively correlated with the frequency of received attacks; however, a negative association occurred following eye darkening, in which the intensity of aggressive interactions decreased. Thus, fish that initially received a high number of attacks signalled subordination more rapidly and intensely (rapid and dramatic eye darkening), thereby inducing a negative social feedback mechanism that led to reduced aggression. Copyright © 2011 Elsevier GmbH. All rights reserved.

Classical dendritic cells mediate fibrosis directly via the retinoic acid pathway in severe eye allergy

PubMed Central

Ahadome, Sarah D.; Mathew, Rose; Reyes, Nancy J.; Mettu, Priyatham S.; Cousins, Scott W.; Calder, Virginia L.; Saban, Daniel R.

2016-01-01

Fibrosis is a shared end-stage pathway to lung, liver, and heart failure. In the ocular mucosa (conjunctiva), fibrosis leads to blindness in trachoma, pemphigoid, and allergy. The indirect fibrogenic role of DCs via T cell activation and inflammatory cell recruitment is well documented. However, here we demonstrate that DCs can directly induce fibrosis. In the mouse model of allergic eye disease (AED), classical CD11b+ DCs in the ocular mucosa showed increased activity of aldehyde dehydrogenase (ALDH), the enzyme required for retinoic acid synthesis. In vitro, CD11b+ DC–derived ALDH was associated with 9-cis-retinoic acid ligation to retinoid x receptor (RXR), which induced conjunctival fibroblast activation. In vivo, stimulating RXR led to rapid onset of ocular mucosal fibrosis, whereas inhibiting ALDH activity in DCs or selectively depleting DCs markedly reduced fibrosis. Collectively, these data reveal a profibrotic ALDH-dependent pathway by DCs and uncover a role for DC retinoid metabolism. PMID:27595139

INTRAVITREOUS CHEMOTHERAPY FOR ACTIVE VITREOUS SEEDING FROM RETINOBLASTOMA: Outcomes After 192 Consecutive Injections. The 2015 Howard Naquin Lecture.

PubMed

Shields, Carol L; Douglass, Alexzandra M; Beggache, Meriem; Say, Emil Anthony T; Shields, Jerry A

2016-06-01

To investigate on the safety and efficacy of intravitreous chemotherapy for retinoblastoma seeding in a relatively large cohort and provide information on the necessary number of injections and long-term control. Retrospective interventional case series of 40 consecutive eyes with viable vitreous seeding after standard treatment of retinoblastoma. All eyes received intravitreal melphalan injection (20-30 μg) and additional topotecan (20 μg) as needed using the trans pars plana route with triple freeze-thaw cryotherapy at needle withdrawal for prevention of extraocular seeding for planned six cycles. The mean patient age at presentation was 36 months, and interval to need for vitreous injection was 14 months. Viable vitreous (n = 40 eyes) and additional subretinal (n = 2 eyes) seeds were documented. There was a total of 192 injections using melphalan (n = 148) and/or topotecan (n = 44) with mean number of injections per eye of melphalan at 4 (median, 4; range, 1-6) and topotecan at 3 (median, 3; range, 1-5). Fewer than six planned melphalan injections (n = 31 cases, 78%) were necessary because of rapid and complete vitreous seed control (n = 30 eyes) or melphalan allergy (n = 1 eye). Fewer than six planned topotecan injections (n = 14 cases, 100%) were necessary because of rapid and complete vitreous seed control in all cases. At median 3-year follow-up, therapeutic success with continued seed regression was observed in all 40 eyes (100%). Globe salvage was attained in 35 cases (88%), and enucleation (n = 5) was necessary for extensive recurrent subretinal seeds (n = 2), neovascular glaucoma with vitreous hemorrhage (n = 2), and hemorrhagic retinal necrosis (n = 1). Side effects included focal retinal pigment epithelial mottling at the site of injection (n = 12), minor focal paraxial lens opacity (not requiring cataract surgery) (n = 11), transient focal vitreous hemorrhage (n = 5), transient hypotony (n = 3), transient retinal hemorrhage (n = 2), optic disc edema (n = 1), and hemorrhagic retinal necrosis (n = 1). There was no case of endophthalmitis, extraocular tumor extension, metastasis, or death. Intravitreal melphalan and/or topotecan injection for retinoblastoma vitreous seeding provides lasting tumor control at 3 years with approximately 4 injections.

Efferent control of temporal response properties of the Limulus lateral eye

PubMed Central

1990-01-01

The sensitivity of the Limulus lateral eye exhibits a pronounced circadian rhythm. At night a circadian oscillator in the brain activates efferent fibers in the optic nerve, inducing multiple changes in the physiological and anatomical characteristics of retinal cells. These changes increase the sensitivity of the retina by about five orders of magnitude. We investigated whether this increase in retinal sensitivity is accompanied by changes in the ability of the retina to process temporal information. We measured the frequency transfer characteristic (FTC) of single receptors (ommatidia) by recording the response of their optic nerve fibers to sinusoidally modulated light. We first measured the FTC in the less sensitive daytime state and then after converting the retina to the more sensitive nighttime state by electrical stimulation of the efferent fibers. The activation of these fibers shifted the peak of the FTC to lower frequencies and reduced the slope of the low-frequency limb. These changes reduce the eye's ability to detect rapid changes in light intensity but enhance its ability to detect dim flashes of light. Apparently Limulus sacrifices temporal resolution for increased visual sensitivity at night. PMID:2307958

Rapid Cataract Progression after Nd:YAG Vitreolysis for Vitreous Floaters: A Case Report and Literature Review.

PubMed

Sun, I-Ting; Lee, Tsung-Han; Chen, Chih-Hsin

2017-01-01

We report a case of rapid cataract progression after Nd:YAG vitreolysis for vitreous floaters. A 55-year-old man presented with acute onset of blurred vision following Nd:YAG vitreolysis for symptomatic floaters in the left eye. His initial best corrected visual acuity (BCVA) was 20/1,000 in the left eye. Ocular examinations showed frost-like opacities of the lens and a suspected break of the posterior capsule in the left eye. There were no detectable retinal lesions. Cataract surgery was then arranged. Posterior capsular rupture and vitreous loss occurred during surgery, which required a subsequent pars plana vitrectomy. After the surgery, BCVA in the left eye gradually improved to 20/20 and was maintained during a 1-year follow-up period. Crystalline lens injuries and rapid cataract progression may occur following Nd:YAG vitreolysis. While dealing with this type of complicated cataract, clinicians should be aware of the possibility of posterior lens capsule rupture during surgery and the need for combined vitrectomy.

The Effects of Fatigue on Position Determination and Cognitive Workload Using a Visual and 3-Dimensional Auditory Display

DTIC Science & Technology

2004-06-01

in first third of the night. REM sleep is associated with an extremely active brain that is frequently dreaming with bursts of rapid eye movement...these areas. 3. Human Sleep and Fatigue Sleep is nature’s process of resting the body although brain activity continues throughout the rest...midday roughly between 1500 and 1700 (LeClair, 2001). Disruption of one’s circadian rhythm to accommodate adjustments in unconventional working hours

Noradrenergic modulation of masseter muscle activity during natural rapid eye movement sleep requires glutamatergic signalling at the trigeminal motor nucleus

PubMed Central

Schwarz, Peter B; Mir, Saba; Peever, John H

2014-01-01

Noradrenergic neurotransmission in the brainstem is closely coupled to changes in muscle activity across the sleep–wake cycle, and noradrenaline is considered to be a key excitatory neuromodulator that reinforces the arousal-related stimulus on motoneurons to drive movement. However, it is unknown if α-1 noradrenoceptor activation increases motoneuron responsiveness to excitatory glutamate (AMPA) receptor-mediated inputs during natural behaviour. We studied the effects of noradrenaline on AMPA receptor-mediated motor activity at the motoneuron level in freely behaving rats, particularly during rapid eye movement (REM) sleep, a period during which both AMPA receptor-triggered muscle twitches and periods of muscle quiescence in which AMPA drive is silent are exhibited. Male rats were subjected to electromyography and electroencephalography recording to monitor sleep and waking behaviour. The implantation of a cannula into the trigeminal motor nucleus of the brainstem allowed us to perfuse noradrenergic and glutamatergic drugs by reverse microdialysis, and thus to use masseter muscle activity as an index of motoneuronal output. We found that endogenous excitation of both α-1 noradrenoceptor and AMPA receptors during waking are coupled to motor activity; however, REM sleep exhibits an absence of endogenous α-1 noradrenoceptor activity. Importantly, exogenous α-1 noradrenoceptor stimulation cannot reverse the muscle twitch suppression induced by AMPA receptor blockade and nor can it elevate muscle activity during quiet REM, a phase when endogenous AMPA receptor activity is subthreshold. We conclude that the presence of an endogenous glutamatergic drive is necessary for noradrenaline to trigger muscle activity at the level of the motoneuron in an animal behaving naturally. PMID:24860176

A Diagnosis of Insomnia Is Associated With Differential Expression of Sleep-Regulating Genes in Military Personnel.

PubMed

Gill, Jessica M; Lee, Hyunhwa; Baxter, Tristin; Reddy, Swarnalatha Y; Barr, Taura; Kim, Hyung-Suk; Wang, Dan; Mysliwiec, Vincent

2015-07-01

Sleep disturbance is a common and disturbing symptom in military personnel, with many individuals progressing to the development of insomnia, which is characterized by increased arousals, wakefulness after sleep onset, and distorted sleep architecture. The molecular mechanisms underlying insomnia remain elusive, limiting future therapeutic development to address this critical issue. We examined whole gene expression profiles associated with insomnia. We compared subjects with insomnia (n = 25) to controls (n = 13) without insomnia using microarray gene expression profiles obtained from peripheral samples of whole blood obtained from military personnel. Compared to controls, participants with insomnia had differential expression of 44 transcripts from 43 identified genes. Among the identified genes, urotensin 2 was downregulated by more than 6 times in insomnia participants, and the fold-change remained significant after controlling for depression, posttraumatic stress disorder, and medication use. Urotensin 2 is involved in regulation of orexin A and B activity and rapid eye movement during sleep. These findings suggest that differential expression of these sleep-regulating genes contributes to symptoms of insomnia and, specifically, that switching between rapid eye movement and nonrapid eye movement sleep stages underlies insomnia symptoms. Future work to identify therapeutic agents that are able to regulate these pathways may provide novel treatments for insomnia. © The Author(s) 2015.

Vestibuloocular reflex of rhesus monkeys after spaceflight

NASA Technical Reports Server (NTRS)

Cohen, Bernard; Kozlovskaia, Inessa; Raphan, Theodore; Solomon, David; Helwig, Denice; Cohen, Nathaniel; Sirota, Mikhail; Iakushin, Sergei

1992-01-01

The vestibuloocular reflex (VOR) of two rhesus monkeys was recorded before and after 14 days of spaceflight. The gain (eye velocity/head velocity) of the horizontal VOR, tested 15 and 18 h after landing, was approximately equal to preflight values. The dominant time constant of the animal tested 15 h after landing was equivalent to that before flight. During nystagmus induced by off-vertical axis rotation (OVAR), the latency, rising time constant, steady-state eye velocity, and phase of modulation in eye velocity and eye position with respect to head position were similar in both monkeys before and after flight. There were changes in the amplitude of modulation of horizontal eye velocity during steady-state OVAR and in the ability to discharge stored activity rapidly by tilting during postrotatory nystagmus (tilt dumping) after flight: OVAR modulations were larger, and tilt dumping was lost in the one animal tested on the day of landing and for several days thereafter. If the gain and time constant of the horizontal VOR exchange in microgravity, they must revert to normal soon after landing. The changes that were observed suggest that adaptation to microgravity had caused alterations in way that the central nervous system processes otolith input.

Phenological Metrics Extraction for Agricultural Land-use Types Using RapidEye and MODIS

NASA Astrophysics Data System (ADS)

Xu, Xingmei; Doktor, Daniel; Conrad, Christopher

2016-04-01

Crop phenology involves the various agricultural events, such as planting, emergence, flowering, development of fruit and harvest. These phenological stages of a crop contain essential information for practical agricultural management, crop productivity estimation, investigations of crop-weather relationships, and also play an important role in improving agricultural land-use classification. In this study, we used MODIS and RapidEye images to extract phenological metrics in central Germany between 2010 and 2014. The Best Index Slope Extraction algorithm was used to remove undesirable data noise from Normalized Difference Vegetation Index (NDVI) time series of both satellite data before fast Fourier transformation was applied. Metrics optimization for phenology of major crops in the study area (winter wheat, winter barley, winter oilseed rape and sugar beet) and validation were performed with intensive ground observations from the German Weather Service (2010-2014) and our own measurements of BBCH code (Biologische Bundesanstalt für Land- und Forstwirtschaft, Bundessortenamt und CHemische Industrie) (in 2014). We found that the dates with maximum NDVI have a close link to the heading stage of cereals (RMSE = 9.48 days for MODIS and RMSE = 13.55 days for RapidEye), and the dates of local half maximum during senescence period of winter crops was strongly related to ripeness stage (BBCH: 87) (RMSE = 8.87 days for MODIS and RMSE = 9.62 days for RapidEye). The root-mean-square errors (RMSE) of derived green up dates for both winter and summer crops were larger than 2 weeks, which was caused by limited number of good quality images during the winter season. Comparison between RapidEye and homogeneous MODIS pixels indicated that phenological metrics derived from both satellites were similar to the crop calendar in this region. We also investigated the influence of spatial aggregation of RapidEye-scale phenology to MODIS scale as well as the effect of decreasing the temporal resolution of MODIS to RapidEye scale. Our method to smooth and construct NDVI time-series works well in monitoring agricultural phenology and can be applied to other areas with daily MODIS data coverage. High spatial resolution data provides us with a unique opportunity to explore within-field phenology variation, and reduce effects of spatial heterogeneity. We suggest that further studies might not have to consider daily or composite-daily observations as first criteria for selection of remote sensing product in terms of phenology extraction, if the crop calendar is reliable.

Large incidence angle and defocus influence cat's eye retro-reflector

NASA Astrophysics Data System (ADS)

Zhang, Lai-xian; Sun, Hua-yan; Zhao, Yan-zhong; Yang, Ji-guang; Zheng, Yong-hui

2014-11-01

Cat's eye lens make the laser beam retro-reflected exactly to the opposite direction of the incidence beam, called cat's eye effect, which makes rapid acquiring, tracking and pointing of free space optical communication possible. Study the influence of cat's eye effect to cat's eye retro-reflector at large incidence angle is useful. This paper analyzed the process of how the incidence angle and focal shit affect effective receiving area, retro-reflected beam divergence angle, central deviation of cat's eye retro-reflector at large incidence angle and cat's eye effect factor using geometrical optics method, and presented the analytic expressions. Finally, numerical simulation was done to prove the correction of the study. The result shows that the efficiency receiving area of cat's eye retro-reflector is mainly affected by incidence angle when the focal shift is positive, and it decreases rapidly when the incidence angle increases; the retro-reflected beam divergence and central deviation is mainly affected by focal shift, and within the effective receiving area, the central deviation is smaller than beam divergence in most time, which means the incidence beam can be received and retro-reflected to the other terminal in most time. The cat's eye effect factor gain is affected by both incidence angle and focal shift.

The Visual Scoring of Sleep in Infants 0 to 2 Months of Age.

PubMed

Grigg-Damberger, Madeleine M

2016-03-01

In March 2014, the American Academy of Sleep Medicine (AASM) Board of Directors requested the Scoring Manual Editorial Board develop rules, terminology, and technical specifications for scoring sleep/wake states in full-term infants from birth to 2 mo of age, cognizant of the 1971 Anders, Emde, and Parmelee Manual for Scoring Sleep in Newborns. On July 1, 2015, the AASM published rules for scoring sleep in infants, ages 0-2 mo. This evidence-based review summarizes the background information provided to the Scoring Manual Editorial Board to write these rules. The Anders Manual only provided criteria for coding physiological and behavioral state characteristics in polysomnograms (PSG) of infants, leaving specific sleep scoring criteria to the individual investigator. Other infant scoring criteria have been published, none widely accepted or used. The AASM Scoring Manual infant scoring criteria incorporate modern concepts, digital PSG recording techniques, practicalities, and compromises. Important tenets are: (1) sleep/wake should be scored in 30-sec epochs as either wakefulness (W), rapid eye movement, REM (R), nonrapid eye movement, NREM (N) and transitional (T) sleep; (2) an electroencephalographic (EEG) montage that permits adequate display of young infant EEG is: F3-M2, F4-M1, C3-M2, C4-M1, O1-M2, O2-M1; additionally, recording C3-Cz, Cz-C4 help detect early and asynchronous sleep spindles; (3) sleep onsets are more often R sleep until 2-3 mo postterm; (4) drowsiness is best characterized by visual observation (supplemented by later video review); (5) wide open eyes is the most crucial determinant of W; (6) regularity (or irregularity) of respiration is the single most useful PSG characteristic for scoring sleep stages at this age; (7) trace alternant (TA) is the only relatively distinctive EEG pattern, characteristic of N sleep, and usually disappears by 1 mo postterm replaced by high voltage slow (HVS); (8) sleep spindles first appear 44-48 w conceptional age (CA) and when present prompt scoring N; (9) score EEG activity in an epoch as "continuous" or "discontinuous" for inter-scorer reliability; (10) score R if four or more of the following conditions are present, including irregular respiration and rapid eye movement(s): (a) low chin EMG (for the majority of the epoch); (b) eyes closed with at least one rapid eye movement (concurrent with low chin tone); (c) irregular respiration; (d) mouthing, sucking, twitches, or brief head movements; and (e) EEG exhibits a continuous pattern without sleep spindles; (11) because rapid eye movements may not be seen on every page, epochs following an epoch of definite R in the absence of rapid eye movements may be scored if the EEG is continuous without TA or sleep spindles, chin muscle tone low for the majority of the epoch; and there is no intervening arousal; (12) Score N if four or more of the following conditions are present, including regular respiration, for the majority of the epoch: (a) eyes are closed with no eye movements; (b) chin EMG tone present; (c) regular respiration; and (d) EEG patterns of either TA, HVS, or sleep spindles are present; and (13) score T sleep if an epoch contains two or more discordant PSG state characteristics (either three NREM and two REM characteristics or two NREM and three REM characteristics). These criteria for ages 0-2 mo represent far more than baby steps. Like all the other AASM Manual rules and specifications none are fixed in stone, all open for debate, discussion and revision with the fundamental goal to provide standards for comparison of methods and results. A commentary on this article appears in this issue on page 291. © 2016 American Academy of Sleep Medicine.

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2

PubMed Central

Schrölkamp, Maren; Jennum, Poul J.; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R.; Knudsen, Stine

2017-01-01

Study Objectives: Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Methods: Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. Results: CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Conclusions: Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy. Citation: Schrölkamp M, Jennum PJ, Gammeltoft S, Holm A, Kornum BR, Knudsen S. Normal morning melanin-concentrating hormone levels and no association with rapid eye movement or non-rapid eye movement sleep parameters in narcolepsy type 1 and type 2. J Clin Sleep Med. 2017;13(2):235–243. PMID:27855741

Sleep-Related Electrophysiology and Behavior of Tinamous (Eudromia elegans): Tinamous Do Not Sleep Like Ostriches.

PubMed

Tisdale, Ryan K; Vyssotski, Alexei L; Lesku, John A; Rattenborg, Niels C

2017-01-01

The functions of slow wave sleep (SWS) and rapid eye movement (REM) sleep, distinct sleep substates present in both mammals and birds, remain unresolved. One approach to gaining insight into their function is to trace the evolution of these states through examining sleep in as many taxonomic groups as possible. The mammalian and avian clades are each composed of two extant groups, i.e., the monotremes (echidna and platypus) and therian (marsupial and eutherian [or placental]) mammals, and Palaeognaths (cassowaries, emus, kiwi, ostriches, rheas, and tinamous) and Neognaths (all other birds) among birds. Previous electrophysiological studies of monotremes and ostriches have identified a unique "mixed" sleep state combining features of SWS and REM sleep unlike the well-delineated sleep states observed in all therian mammals and Neognath birds. In the platypus this state is characterized by periods of REM sleep-related myoclonic twitching, relaxed skeletal musculature, and rapid eye movements, occurring in conjunction with SWS-related slow waves in the forebrain electroencephalogram (EEG). A similar mixed state was also observed in ostriches; although in addition to occurring during periods with EEG slow waves, reduced muscle tone and rapid eye movements also occurred in conjunction with EEG activation, a pattern typical of REM sleep in Neognath birds. Collectively, these studies suggested that REM sleep occurring exclusively as an integrated state with forebrain activation might have evolved independently in the therian and Neognath lineages. To test this hypothesis, we examined sleep in the elegant crested tinamou (Eudromia elegans), a small Palaeognath bird that more closely resembles Neognath birds in size and their ability to fly. A 24-h period was scored for sleep state based on electrophysiology and behavior. Unlike ostriches, but like all of the Neognath birds examined, all indicators of REM sleep usually occurred in conjunction with forebrain activation in tinamous. The absence of a mixed REM sleep state in tinamous calls into question the idea that this state is primitive among Palaeognath birds and therefore birds in general. © 2017 S. Karger AG, Basel.

Eye Contact Facilitates Awareness of Faces during Interocular Suppression

ERIC Educational Resources Information Center

Stein, Timo; Senju, Atsushi; Peelen, Marius V.; Sterzer, Philipp

2011-01-01

Eye contact captures attention and receives prioritized visual processing. Here we asked whether eye contact might be processed outside conscious awareness. Faces with direct and averted gaze were rendered invisible using interocular suppression. In two experiments we found that faces with direct gaze overcame such suppression more rapidly than…

Sustained ocular delivery of brimonidine tartrate using ion activated in situ gelling system.

PubMed

Geethalakshmi, A; Karki, Roopa; Jha, Sajal Kumar; Venkatesh, D P; Nikunj, B

2012-03-01

The poor bioavailability and therapeutic response exhibited by conventional eye drops due to rapid precorneal elimination of the drug may be overcome by the use of an in situ gelling systems that are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac which improves patient compliance as the dosage regimen is one drop of the dosage form twice a day. The loss of drug overcomes due to the immediate gel formation between the eye membrane and the drug being entrapped simultaneously in sol-gel transition in the cul de sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of an antiglaucomal agent, brimonidine tartrate based on the concept of ion-activated in situ gelation. Gelrite was used as the gelling agent, which gels in the presence of mono or divalent cations present in the lacrimal fluid. The formulations were evaluated for clarity, pH measurement, gelling capacity, drug content estimation, rheological study, in-vitro diffusion study, antibacterial activity, isotonicity testing, eye irritation testing. In the developed formulations Gelrite Brimonidine-3 (GB3) exhibited sustained release of drug from formulation over a period of 8 hrs thus increasing residence time of the drug, non-irritating with no ocular damage or abnormal clinical signs to the cornea, iris or conjunctiva, stable and sterile. These results demonstrate that the developed system is an alternative to conventional ophthalmic drops, with better patient compliance, and is industrially oriented and economical.

Importance of Rapid Eye Movement Sleep Behavior Disorder to the Primary Care Physician.

PubMed

McCarter, Stuart J; Howell, Michael J

2016-10-01

Sleep disorders and neurodegenerative diseases are commonly encountered in primary care. A common, but underdiagnosed sleep disorder, rapid eye movement sleep behavior disorder (RBD), is highly associated with Parkinson disease and related disorders. Rapid eye movement sleep behavior disorder is common. It is estimated to affect 0.5% of the general population and more than 7% of individuals older than 60 years; however, most cases go unrecognized. Rapid eye movement sleep behavior disorder presents as dream enactment, often with patients thrashing, punching, and kicking while they are sleeping. Physicians can quickly assess for the presence of RBD with high sensitivity and specificity by asking patients the question "Have you ever been told that you act out your dreams, for example by punching or flailing your arms in the air or screaming and shouting in your sleep?" Patients with RBD exhibit subtle signs of neurodegenerative disease, such as mild motor slowing, constipation, or changes in sense of smell. These signs and symptoms may predict development of a neurodegenerative disease within 3 years. Ultimately, most patients with RBD develop a neurodegenerative disease, highlighting the importance of serial neurological examinations to assess for the presence of parkinsonism and/or cognitive impairment and prognostic counseling for these patients. Rapid eye movement sleep behavior disorder is treatable with melatonin (3-6 mg before bed) or clonazepam (0.5-1 mg before bed) and may be the most common, reversible cause of sleep-related injury. Thus, it is important to identify patients at risk of RBD in a primary care setting so that bedroom safety can be addressed and treatment may be initiated. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

Predicting stem borer density in maize using RapidEye data and generalized linear models

NASA Astrophysics Data System (ADS)

Abdel-Rahman, Elfatih M.; Landmann, Tobias; Kyalo, Richard; Ong'amo, George; Mwalusepo, Sizah; Sulieman, Saad; Ru, Bruno Le

2017-05-01

Average maize yield in eastern Africa is 2.03 t ha-1 as compared to global average of 6.06 t ha-1 due to biotic and abiotic constraints. Amongst the biotic production constraints in Africa, stem borers are the most injurious. In eastern Africa, maize yield losses due to stem borers are currently estimated between 12% and 21% of the total production. The objective of the present study was to explore the possibility of RapidEye spectral data to assess stem borer larva densities in maize fields in two study sites in Kenya. RapidEye images were acquired for the Bomet (western Kenya) test site on the 9th of December 2014 and on 27th of January 2015, and for Machakos (eastern Kenya) a RapidEye image was acquired on the 3rd of January 2015. Five RapidEye spectral bands as well as 30 spectral vegetation indices (SVIs) were utilized to predict per field maize stem borer larva densities using generalized linear models (GLMs), assuming Poisson ('Po') and negative binomial ('NB') distributions. Root mean square error (RMSE) and ratio prediction to deviation (RPD) statistics were used to assess the models performance using a leave-one-out cross-validation approach. The Zero-inflated NB ('ZINB') models outperformed the 'NB' models and stem borer larva densities could only be predicted during the mid growing season in December and early January in both study sites, respectively (RMSE = 0.69-1.06 and RPD = 8.25-19.57). Overall, all models performed similar when all the 30 SVIs (non-nested) and only the significant (nested) SVIs were used. The models developed could improve decision making regarding controlling maize stem borers within integrated pest management (IPM) interventions.

Dopamine agonist suppression of rapid-eye-movement sleep is secondary to sleep suppression mediated via limbic structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miletich, R.S.

The effects of pergolide, a direct dopamine receptor agonist, on sleep and wakefulness, motor behavior and /sup 3/H-spiperone specific binding in limbic structures and striatum in rats was studied. The results show that pergolide induced a biphasic dose effect, with high doses increasing wakefulness and suppressing sleep while low dose decreased wakefulness, but increased sleep. It was shown that pergolide-induced sleep suppression was blocked by ..cap alpha..-glupenthixol and pimozide, two dopamine receptor antagonists. It was further shown that pergolide merely delayed the rebound resulting from rapid-eye-movement (REM) sleep deprivation, that dopamine receptors stimulation had no direct effect on the period,more » phase or amplitude of the circadian rhythm of REM sleep propensity and that there was no alteration in the coupling of REM sleep episodes with S/sub 2/ episodes. Rapid-eye-movement sleep deprivation resulted in increased sensitivity to the pergolide-induced wakefulness stimulation and sleep suppression and pergolide-induced motor behaviors of locomotion and head bobbing. /sup 3/H-spiperone specific binding to dopamine receptors was shown to be altered by REM sleep deprivation in the subcortical limbic structures. It is concluded that the REM sleep suppressing action of dopamine receptor stimulation is secondary to sleep suppression per se and not secondary to a unique effect on the REM sleep. Further, it is suggested that the wakefulness stimulating action of dopamine receptor agonists is mediated by activation of the dopamine receptors in the terminal areas of the mesolimbocortical dopamine projection system.« less

The living eye "disarms" uncommitted autoreactive T cells by converting them to Foxp3(+) regulatory cells following local antigen recognition.

PubMed

Zhou, Ru; Horai, Reiko; Silver, Phyllis B; Mattapallil, Mary J; Zárate-Bladés, Carlos R; Chong, Wai Po; Chen, Jun; Rigden, Rachael C; Villasmil, Rafael; Caspi, Rachel R

2012-02-15

Immune privilege is used by the eye, brain, reproductive organs, and gut to preserve structural and functional integrity in the face of inflammation. The eye is arguably the most vulnerable and, therefore, also the most "privileged" of tissues; paradoxically, it remains subject to destructive autoimmunity. It has been proposed, although never proven in vivo, that the eye can induce T regulatory cells (Tregs) locally. Using Foxp3-GFP reporter mice expressing a retina-specific TCR, we now show that uncommitted T cells rapidly convert in the living eye to Foxp3(+) Tregs in a process involving retinal Ag recognition, de novo Foxp3 induction, and proliferation. This takes place within the ocular tissue and is supported by retinoic acid, which is normally present in the eye because of its function in the chemistry of vision. Nonconverted T cells showed evidence of priming but appeared restricted from expressing effector function in the eye. Pre-existing ocular inflammation impeded conversion of uncommitted T cells into Tregs. Importantly, retina-specific T cells primed in vivo before introduction into the eye were resistant to Treg conversion in the ocular environment and, instead, caused severe uveitis. Thus, uncommitted T cells can be disarmed, but immune privilege is unable to protect from uveitogenic T cells that have acquired effector function prior to entering the eye. These findings shed new light on the phenomenon of immune privilege and on its role, as well as its limitations, in actively controlling immune responses in the tissue.

The Living Eye “Disarms” Uncommitted Autoreactive T Cells by Converting Them to FoxP3+ Regulatory Cells Following Local Antigen Recognition

PubMed Central

Zhou, Ru; Horai, Reiko; Silver, Phyllis B; Mattapallil, Mary J; Zárate-Bladés, Carlos R; Chong, Wai Po; Chen, Jun; Rigden, Rachael C; Villasmil, Rafael; Caspi, Rachel R

2011-01-01

Immune privilege is used by the eye, brain, reproductive organs and gut to preserve structural and functional integrity in the face of inflammation. The eye is arguably the most vulnerable, and therefore also the most “privileged” of tissues, but paradoxically, remains subject to destructive autoimmunity. It has been proposed, although never proven in vivo, that the eye can induce T regulatory cells (Tregs) locally. Using FoxP3-GFP reporter mice expressing a retina-specific T cell receptor, we now show that uncommitted T cells rapidly convert in the living eye to FoxP3+ Tregs in a process involving retinal antigen recognition, de novo FoxP3 induction and proliferation. This takes place within the ocular tissue and is supported by retinoic acid, which is normally present in the eye due to its function in the chemistry of vision. Non-converted T cells showed evidence of priming, but appeared restricted from expressing effector function in the eye. Preexisting ocular inflammation impeded conversion of uncommitted T cells into Tregs. Importantly, retina-specific T cells primed in vivo before introduction into the eye were resistant to Treg conversion in the ocular environment, and instead caused severe uveitis. Thus, uncommitted T cells can be disarmed, but immune privilege is unable to protect from uveitogenic T cells that have acquired effector function prior to entering the eye. These findings shed new light on the phenomenon of immune privilege and on its role, as well as its limitations, in actively controlling immune responses in the tissue. PMID:22238462

β Oscillation during Slow Wave Sleep and Rapid Eye Movement Sleep in the Electroencephalogram of a Transgenic Mouse Model of Huntington’s Disease

PubMed Central

Jeantet, Yannick; Cayzac, Sebastien; Cho, Yoon H.

2013-01-01

Study objectives To search for early abnormalities in electroencephalogram (EEG) during sleep which may precede motor symptoms in a transgenic mouse model of hereditary neurodegenerative Huntington’s disease (HD). Design In the R6/1 transgenic mouse model of HD, rhythmic brain activity in EEG recordings was monitored longitudinally and across vigilance states through the onset and progression of disease. Measurements and results Mice with chronic electrode implants were recorded monthly over wake-sleep cycles (4 hours), beginning at 9–11 weeks (presymptomatic period) through 6–7 months (symptomatic period). Recording data revealed a unique β rhythm (20–35 Hz), present only in R6/1 transgenic mice, which evolves in close parallel with the disease. In addition, there was an unusual relationship between this β oscillation and vigilance states: while nearly absent during the active waking state, the β oscillation appeared with drowsiness and during slow wave sleep (SWS) and, interestingly, strengthened rather than dissipating when the brain returned to an activated state during rapid eye movement (REM) sleep. Conclusions In addition to providing a new in vivo biomarker and insight into Huntington's disease pathophysiology, this serendipitous observation opens a window onto the rarely explored neurophysiology of the cortico-basal ganglia circuit during SWS and REM sleep. PMID:24244517

The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep.

PubMed

Yang, Su-Rong; Hu, Zhen-Zhen; Luo, Yan-Jia; Zhao, Ya-Nan; Sun, Huan-Xin; Yin, Dou; Wang, Chen-Yao; Yan, Yu-Dong; Wang, Dian-Ru; Yuan, Xiang-Shan; Ye, Chen-Bo; Guo, Wei; Qu, Wei-Min; Cherasse, Yoan; Lazarus, Michael; Ding, Yu-Qiang; Huang, Zhi-Li

2018-04-01

The rostromedial tegmental nucleus (RMTg), also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep-wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM) sleep with increased slow-wave activity (SWA). Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep-wake cycle were mimicked by the modulation of ventral tegmental area (VTA)/substantia nigra compacta (SNc) dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation.

The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep

PubMed Central

Hu, Zhen-Zhen; Luo, Yan-Jia; Zhao, Ya-Nan; Sun, Huan-Xin; Yin, Dou; Wang, Chen-Yao; Yan, Yu-Dong; Wang, Dian-Ru; Yuan, Xiang-Shan; Ye, Chen-Bo; Guo, Wei; Qu, Wei-Min; Cherasse, Yoan; Lazarus, Michael; Ding, Yu-Qiang; Huang, Zhi-Li

2018-01-01

The rostromedial tegmental nucleus (RMTg), also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep–wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM) sleep with increased slow-wave activity (SWA). Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep–wake cycle were mimicked by the modulation of ventral tegmental area (VTA)/substantia nigra compacta (SNc) dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation. PMID:29652889

Pedunculopontine Gamma Band Activity and Development.

PubMed

Garcia-Rill, Edgar; Luster, Brennon; Mahaffey, Susan; MacNicol, Melanie; Hyde, James R; D'Onofrio, Stasia M; Phillips, Cristy

2015-12-03

This review highlights the most important discovery in the reticular activating system in the last 10 years, the manifestation of gamma band activity in cells of the reticular activating system (RAS), especially in the pedunculopontine nucleus, which is in charge of waking and rapid eye movement (REM) sleep. The identification of different cell groups manifesting P/Q-type Ca(2+) channels that control waking vs. those that manifest N-type channels that control REM sleep provides novel avenues for the differential control of waking vs. REM sleep. Recent discoveries on the development of this system can help explain the developmental decrease in REM sleep and the basic rest-activity cycle.

Otolithic influences on extraocular and intraocular muscles

NASA Technical Reports Server (NTRS)

Gernandt, B. E.

1973-01-01

Selective stimulation of utricular gravireceptors leads to gross activation of the bulbar reticular formation where a strong interaction with evoked spino-bulbo-spinal reflex activity occurs. The utricular neurons encountered by microelectrodes in the lateral vestibular nuclei show four types of elicited activity; two of these display an increased firing rate, and two exhibit pronounced inhibitory effects. Application of a stimulus of long duration and constant intensity to the utricle has shown that rapid adaptation of the peripheral receptors is a prominent feature. The effects of selective utricular stimulation upon eye movements, as recorded by the corneoretinal potential method, have been studied in experiments on cats and monkeys and it can be firmly stated that prolonged stimulation of the utricle can evoke strong primary nystagmus, followed by a secondary nystagmus at the cessation of stimulation. The action of utricular stimulation on ocular reflexes has been examined further, with particular attention to evoked pupillary reactions in both cats and monkeys: constriction during the fast phase of the brisk conjugate eye movement, and dilatation during the flow phase.

BK channels are required for multisensory plasticity in the oculomotor system

PubMed Central

Nelson, Alexandra; Faulstich, Michael; Moghadam, Setareh; Onori, Kimberly; Meredith, Andrea; du Lac, Sascha

2017-01-01

SUMMARY Neural circuits are endowed with several forms of intrinsic and synaptic plasticity that could contribute to adaptive changes in behavior, but circuit complexities have hindered linking specific cellular mechanisms with their behavioral consequences. Eye movements generated by simple brainstem circuits provide a means for relating cellular plasticity to behavioral gain control. Here we show that firing rate potentiation, a form of intrinsic plasticity mediated by reductions in BK-type calcium activated potassium currents in spontaneously firing neurons, is engaged during optokinetic reflex compensation for inner ear dysfunction. Vestibular loss triggers transient increases in postsynaptic excitability, occlusion of firing rate potentiation, and reductions in BK currents in vestibular nucleus neurons. Concurrently, adaptive increases in visually-evoked eye movements rapidly restore oculomotor function in wildtype mice but are profoundly impaired in BK channel null mice. Activity-dependent regulation of intrinsic excitability may be a general mechanism for adaptive control of behavioral output in multisensory circuits. PMID:27989457

Exploiting machine learning algorithms for tree species classification in a semiarid woodland using RapidEye image

NASA Astrophysics Data System (ADS)

Adelabu, Samuel; Mutanga, Onisimo; Adam, Elhadi; Cho, Moses Azong

2013-01-01

Classification of different tree species in semiarid areas can be challenging as a result of the change in leaf structure and orientation due to soil moisture constraints. Tree species mapping is, however, a key parameter for forest management in semiarid environments. In this study, we examined the suitability of 5-band RapidEye satellite data for the classification of five tree species in mopane woodland of Botswana using machine leaning algorithms with limited training samples.We performed classification using random forest (RF) and support vector machines (SVM) based on EnMap box. The overall accuracies for classifying the five tree species was 88.75 and 85% for both SVM and RF, respectively. We also demonstrated that the new red-edge band in the RapidEye sensor has the potential for classifying tree species in semiarid environments when integrated with other standard bands. Similarly, we observed that where there are limited training samples, SVM is preferred over RF. Finally, we demonstrated that the two accuracy measures of quantity and allocation disagreement are simpler and more helpful for the vast majority of remote sensing classification process than the kappa coefficient. Overall, high species classification can be achieved using strategically located RapidEye bands integrated with advanced processing algorithms.

Rapid Cataract Progression after Nd:YAG Vitreolysis for Vitreous Floaters: A Case Report and Literature Review

PubMed Central

Sun, I-Ting; Lee, Tsung-Han; Chen, Chih-Hsin

2017-01-01

Purpose We report a case of rapid cataract progression after Nd:YAG vitreolysis for vitreous floaters. Case Report A 55-year-old man presented with acute onset of blurred vision following Nd:YAG vitreolysis for symptomatic floaters in the left eye. His initial best corrected visual acuity (BCVA) was 20/1,000 in the left eye. Ocular examinations showed frost-like opacities of the lens and a suspected break of the posterior capsule in the left eye. There were no detectable retinal lesions. Cataract surgery was then arranged. Posterior capsular rupture and vitreous loss occurred during surgery, which required a subsequent pars plana vitrectomy. After the surgery, BCVA in the left eye gradually improved to 20/20 and was maintained during a 1-year follow-up period. Conclusion Crystalline lens injuries and rapid cataract progression may occur following Nd:YAG vitreolysis. While dealing with this type of complicated cataract, clinicians should be aware of the possibility of posterior lens capsule rupture during surgery and the need for combined vitrectomy. PMID:28626418

Neural basis for eye velocity generation in the vestibular nuclei of alert monkeys during off-vertical axis rotation

NASA Technical Reports Server (NTRS)

Reisine, H.; Raphan, T.; Cohen, B. (Principal Investigator)

1992-01-01

Activity of "vestibular only" (VO) and "vestibular plus saccade" (VPS) units was recorded in the rostral part of the medial vestibular nucleus and caudal part of the superior vestibular nucleus of alert rhesus monkeys. By estimating the "null axes" of recorded units (n = 79), the optimal plane of activation was approximately the mean plane of reciprocal semicircular canals, i.e., lateral canals, left anterior-right posterior (LARP) canals or right anterior-left posterior (RALP) canals. All units were excited by rotation in a direction that excited a corresponding ipsilateral semicircular canal. Thus, they all displayed a "type I" response. With the animal upright, there were rapid changes in firing rates of both VO and VPS units in response to steps of angular velocity about a vertical axis. The units were bidirectionally activated during vestibular nystagmus (VN), horizontal optokinetic nystagmus (OKN), optokinetic after-nystagmus (OKAN) and off-vertical axis rotation (OVAR). The rising and falling time constants of the responses to rotation indicated that they were closely linked to velocity storage. There were differences between VPS and VO neurons in that activity of VO units followed the expected time course in response to a stimulus even during periods of drowsiness, when eye velocity was reduced. Firing rates of VPS units, on the other hand, were significantly reduced in the drowsy state. Lateral canal-related units had average firing rates that were linearly related to the bias or steady state level of horizontal eye velocity during OVAR over a range of +/- 60 deg/s. These units could be further divided into two classes according to whether they were modulated during OVAR. Non-modulated units (n = 5) were VO types and all modulated units (n = 5) were VPS types. There was no significant difference between the bias level sensitivities relative to eye velocity of the units with and without modulation (P > 0.05). The modulated units had no sustained change in firing rate in response to static head tilts and their phases relative to head position varied from unit to unit. The phase did not appear to be linked to the modulation of horizontal eye velocity during OVAR. The sensitivities of unit activity to eye velocity were similar during all stimulus modalities despite the different gains of eye velocity vs stimulus velocity during VN, OKN and OVAR. Therefore, VO and VPS units are likely to carry an eye velocity signal related to velocity storage.(ABSTRACT TRUNCATED AT 400 WORDS).

The fluid mechanics of scleral buckling surgery for the repair of retinal detachment.

PubMed

Foster, William Joseph; Dowla, Nadia; Joshi, Saurabh Y; Nikolaou, Michael

2010-01-01

Scleral buckling is a common surgical technique used to treat retinal detachments that involves suturing a radial or circumferential silicone element on the sclera. Although this procedure has been performed since the 1960s, and there is a reasonable experimental model of retinal detachment, there is still debate as to how this surgery facilitates the re-attachment of the retina. Finite element calculations using the COMSOL Multiphysics system are utilized to explain the influence of the scleral buckle on the flow of sub-retinal fluid in a physical model of retinal detachment. We found that, by coupling fluid mechanics with structural mechanics, laminar fluid flow and the Bernoulli effect are necessary for a physically consistent explanation of retinal reattachment. Improved fluid outflow and retinal reattachment are found with low fluid viscosity and rapid eye movements. A simulation of saccadic eye movements was more effective in removing sub-retinal fluid than slower, reading speed, eye movements in removing subretinal fluid. The results of our simulations allow us to explain the physical principles behind scleral buckling surgery and provide insight that can be utilized clinically. In particular, we find that rapid eye movements facilitate more rapid retinal reattachment. This is contradictory to the conventional wisdom of attempting to minimize eye movements.

Asymmetries in the Control of Saccadic Eye Movements to Bifurcating Targets.

ERIC Educational Resources Information Center

Zeevi, Yehoshua Y.; And Others

The examination of saccadic eye movements--rapid shifts in gaze from one visual area of interest to another--is useful in studying pilot's visual learning in flight simulator training. Saccadic eye movements are the basic oculomotor response associated with the acquisition of visual information and provide an objective measure of higher perceptual…

Sleep Dysfunction and EEG Alterations in Mice Overexpressing Alpha-Synuclein

PubMed Central

McDowell, Kimberly A.; Shin, David; Roos, Kenneth P.; Chesselet, Marie-Françoise

2018-01-01

Background: Sleep disruptions occur early and frequently in Parkinson’s disease (PD). PD patients also show a slowing of resting state activity. Alpha-synuclein is causally linked to PD and accumulates in sleep-related brain regions. While sleep problems occur in over 75% of PD patients and severely impact the quality of life of patients and caregivers, their study is limited by a paucity of adequate animal models. Objective: The objective of this study was to determine whether overexpression of wildtype alpha-synuclein could lead to alterations in sleep patterns reminiscent of those observed in PD by measuring sleep/wake activity with rigorous quantitative methods in a well-characterized genetic mouse model. Methods: At 10 months of age, mice expressing human wildtype alpha-synuclein under the Thy-1 promoter (Thy1-aSyn) and wildtype littermates underwent the subcutaneous implantation of a telemetry device (Data Sciences International) for the recording of electromyograms (EMG) and electroencephalograms (EEG) in freely moving animals. Surgeries and data collection were performed without knowledge of mouse genotype. Results: Thy1-aSyn mice showed increased non-rapid eye movement sleep during their quiescent phase, increased active wake during their active phase, and decreased rapid eye movement sleep over a 24-h period, as well as a shift in the density of their EEG power spectra toward lower frequencies with a significant decrease in gamma power during wakefulness. Conclusions: Alpha-synuclein overexpression in mice produces sleep disruptions and altered oscillatory EEG activity reminiscent of PD, and this model provides a novel platform to assess mechanisms and therapeutic strategies for sleep dysfunction in PD. PMID:24867919

Children and adults integrate talker and verb information in online processing.

PubMed Central

Borovsky, Arielle; Creel, Sarah

2015-01-01

Children seem able to efficiently interpret a variety of linguistic cues during speech comprehension, yet have difficulty interpreting sources of non-linguistic and paralinguistic information that accompany speech. The current study asked whether (paralinguistic) voice-activated role knowledge is rapidly interpreted in coordination with a linguistic cue (a sentential action) during speech comprehension in an eye-tracked sentence comprehension task with children (aged 3-10) and college-aged adults. Participants were initially familiarized with two talkers who identified their respective roles (e.g. PRINCESS and PIRATE) before hearing a previously-introduced talker name an action and object (“I want to hold the sword,” in the pirate's voice). As the sentence was spoken, eye-movements were recorded to four objects that varied in relationship to the sentential talker and action (Target: SWORD, Talker-Related: SHIP, Action-Related: WAND, and Unrelated: CARRIAGE). The task was to select the named image. Even young child listeners rapidly combined inferences about talker identity with the action, allowing them to fixate on the Target before it was mentioned, although there were developmental and vocabulary differences on this task. Results suggest that children, like adults, store real-world knowledge of a talker's role and actively use this information to interpret speech. PMID:24611671

Albinism

MedlinePlus

... normal skin and hair Patches of missing skin color Many forms of albinism are associated with the following symptoms: Crossed eyes Light sensitivity Rapid eye movements Vision problems, or functional blindness Exams and Tests Genetic testing offers the most ...

Dynamic sound localization in cats

PubMed Central

Ruhland, Janet L.; Jones, Amy E.

2015-01-01

Sound localization in cats and humans relies on head-centered acoustic cues. Studies have shown that humans are able to localize sounds during rapid head movements that are directed toward the target or other objects of interest. We studied whether cats are able to utilize similar dynamic acoustic cues to localize acoustic targets delivered during rapid eye-head gaze shifts. We trained cats with visual-auditory two-step tasks in which we presented a brief sound burst during saccadic eye-head gaze shifts toward a prior visual target. No consistent or significant differences in accuracy or precision were found between this dynamic task (2-step saccade) and the comparable static task (single saccade when the head is stable) in either horizontal or vertical direction. Cats appear to be able to process dynamic auditory cues and execute complex motor adjustments to accurately localize auditory targets during rapid eye-head gaze shifts. PMID:26063772

Rapid Eye Movement Sleep Abnormalities in Children with Pediatric Acute-Onset Neuropsychiatric Syndrome (PANS)

PubMed Central

Gaughan, Thomas; Buckley, Ashura; Hommer, Rebecca; Grant, Paul; Williams, Kyle; Leckman, James F.; Swedo, Susan E.

2016-01-01

Study Objectives: Polysomnographic investigation of sleep architecture in children presenting with pediatric acute-onset neuropsychiatric syndrome (PANS). Methods: Fifteen consecutive subjects meeting criteria for PANS (mean age = 7.2 y; range 3–10 y) underwent single-night full polysomnography (PSG) read by a pediatric neurologist. Results: Thirteen of 15 subjects (87%) had abnormalities detected with PSG. Twelve of 15 had evidence of rapid eye movement (REM) sleep motor disinhibition, as characterized by excessive movement, laughing, hand stereotypies, moaning, or the continuation of periodic limb movements during sleep (PLMS) into REM sleep. Conclusions: This study shows various forms of REM sleep motor disinhibition present in a population of children with PANS. Citation: Gaughan T, Buckley A, Hommer R, Grant P; Williams K, Leckman JF, Swedo SE. Rapid eye movement sleep abnormalities in children with pediatric acute-onset neuropsychiatric syndrome (PANS). J Clin Sleep Med 2016;12(7):1027–1032. PMID:27166296

Detection of carbapenemase activity in Enterobacteriaceae using LC-MS/MS in comparison with the neo-rapid CARB kit using direct visual assessment and colorimetry.

PubMed

Huber, Charlotte A; Sidjabat, Hanna E; Zowawi, Hosam M; Kvaskoff, David; Reed, Sarah; McNamara, John F; McCarthy, Kate L; Harris, Patrick; Toh, Benjamin; Wailan, Alexander M; Paterson, David L

2016-12-01

It has been described that the sensitivity of the Carba NP test may be low in the case of OXA-48-like carbapenamases and mass spectrometry based methods as well as a colorimetry based method have been described as alternatives. We evaluated 84 Enterobacteriaceae isolates including 31 OXA-48-like producing isolates and 13 isolates that produced either an imipenemase (IMP; n=8), New Delhi metallo-β-lactamase (NDM; n=3), or Klebsiella pneumoniae carbapenemase (KPC; n=2), as well as 40 carbapenemase negative Enterobacteriaceae isolates. We used the Neo-Rapid CARB kit, assessing the results with the unaided eye and compared it with a colorimetric approach. Furthermore, we incubated the isolates in growth media with meropenem and measured the remaining meropenem after one and 2h of incubation, respectively, using liquid chromatography tandem mass spectrometry (LC-MS/MS). Whilst all carbapenemase producing isolates with the exception of the OXA-244 producer tested positive for both the Neo-rapid CARB test using the unaided eye or colorimetry, and the 13 isolates producing either IMP, NDM or KPC hydrolysed the meropenem in the media almost completely after 2h of incubation, the 31 OXA-48-like producing isolates exhibited very variable hydrolytic activity when incubated in growth media with meropenem. In our study, the Neo-Rapid CARB test yielded a sensitivity of 98% for both the traditional and the colorimetric approach with a specificity of 95% and 100% respectively. Our results indicate that the Neo-Rapid CARB test may have use for the detection of OXA-48 type carbapenemases and that it may be particularly important to ensure bacterial lysis for the detection of these weaker hydrolysers. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Saccadic Eye Movements Impose a Natural Bottleneck on Visual Short-Term Memory

ERIC Educational Resources Information Center

Ohl, Sven; Rolfs, Martin

2017-01-01

Visual short-term memory (VSTM) is a crucial repository of information when events unfold rapidly before our eyes, yet it maintains only a fraction of the sensory information encoded by the visual system. Here, we tested the hypothesis that saccadic eye movements provide a natural bottleneck for the transition of fragile content in sensory memory…

Genetics Home Reference: CASK-related intellectual disability

MedlinePlus

... XL-ID with or without nystagmus (rapid, involuntary eye movements) is a milder form of CASK -related intellectual ... to promote development of the nerves that control eye movement (the oculomotor neural network). Mutations in the CASK ...

Macaque Pontine Omnipause Neurons Play No Direct Role in the Generation of Eye Blinks

PubMed Central

Schultz, K. P.; Williams, C. R.

2010-01-01

We recorded the activity of pontine omnipause neurons (OPNs) in two macaques during saccadic eye movements and blinks. As previously reported, we found that OPNs fire tonically during fixation and pause about 15 ms before a saccadic eye movement. In contrast, for blinks elicited by air puffs, the OPNs paused <2 ms before the onset of the blink. Thus the burst in the agonist orbicularis oculi motoneurons (OOMNs) and the pause in the antagonist levator palpabrae superioris motoneurons (LPSMNs) necessarily precede the OPN pause. For spontaneous blinks there was no correlation between blink and pause onsets. In addition, the OPN pause continued for 40–60 ms after the time of the maximum downward closing of the eyelids, which occurs around the end of the OOMN burst of firing. LPSMN activity is not responsible for terminating the OPN pause because OPN resumption was very rapid, whereas the resumption of LPSMN firing during the reopening phase is gradual. OPN pause onset does not directly control blink onset, nor does pause offset control or encode the transition between the end of the OOMN firing and the resumption of the LPSMNs. The onset of the blink-related eye transients preceded both blink and OPN pause onsets. Therefore they initiated while the saccadic short-lead burst neurons were still fully inhibited by the OPNs and cannot be saccadic in origin. The abrupt dynamic change of the vertical eye transients from an oscillatory behavior to a single time constant exponential drift predicted the resumption of the OPNs. PMID:20164389

A unified dynamic neural field model of goal directed eye movements

NASA Astrophysics Data System (ADS)

Quinton, J. C.; Goffart, L.

2018-01-01

Primates heavily rely on their visual system, which exploits signals of graded precision based on the eccentricity of the target in the visual field. The interactions with the environment involve actively selecting and focusing on visual targets or regions of interest, instead of contemplating an omnidirectional visual flow. Eye-movements specifically allow foveating targets and track their motion. Once a target is brought within the central visual field, eye-movements are usually classified into catch-up saccades (jumping from one orientation or fixation to another) and smooth pursuit (continuously tracking a target with low velocity). Building on existing dynamic neural field equations, we introduce a novel model that incorporates internal projections to better estimate the current target location (associated to a peak of activity). Such estimate is then used to trigger an eye movement, leading to qualitatively different behaviours depending on the dynamics of the whole oculomotor system: (1) fixational eye-movements due to small variations in the weights of projections when the target is stationary, (2) interceptive and catch-up saccades when peaks build and relax on the neural field, (3) smooth pursuit when the peak stabilises near the centre of the field, the system reaching a fixed point attractor. Learning is nevertheless required for tracking a rapidly moving target, and the proposed model thus replicates recent results in the monkey, in which repeated exercise permits the maintenance of the target within in the central visual field at its current (here-and-now) location, despite the delays involved in transmitting retinal signals to the oculomotor neurons.

Validation of an integrated software for the detection of rapid eye movement sleep behavior disorder.

PubMed

Frauscher, Birgit; Gabelia, David; Biermayr, Marlene; Stefani, Ambra; Hackner, Heinz; Mitterling, Thomas; Poewe, Werner; Högl, Birgit

2014-10-01

Rapid eye movement sleep without atonia (RWA) is the polysomnographic hallmark of REM sleep behavior disorder (RBD). To partially overcome the disadvantages of manual RWA scoring, which is time consuming but essential for the accurate diagnosis of RBD, we aimed to validate software specifically developed and integrated with polysomnography for RWA detection against the gold standard of manual RWA quantification. Academic referral center sleep laboratory. Polysomnographic recordings of 20 patients with RBD and 60 healthy volunteers were analyzed. N/A. Motor activity during REM sleep was quantified manually and computer assisted (with and without artifact detection) according to Sleep Innsbruck Barcelona (SINBAR) criteria for the mentalis ("any," phasic, tonic electromyographic [EMG] activity) and the flexor digitorum superficialis (FDS) muscle (phasic EMG activity). Computer-derived indices (with and without artifact correction) for "any," phasic, tonic mentalis EMG activity, phasic FDS EMG activity, and the SINBAR index ("any" mentalis + phasic FDS) correlated well with the manually derived indices (all Spearman rhos 0.66-0.98). In contrast with computerized scoring alone, computerized scoring plus manual artifact correction (median duration 5.4 min) led to a significant reduction of false positives for "any" mentalis (40%), phasic mentalis (40.6%), and the SINBAR index (41.2%). Quantification of tonic mentalis and phasic FDS EMG activity was not influenced by artifact correction. The computer algorithm used here appears to be a promising tool for REM sleep behavior disorder detection in both research and clinical routine. A short check for plausibility of automatic detection should be a basic prerequisite for this and all other available computer algorithms. © 2014 Associated Professional Sleep Societies, LLC.

Activation of inactivation process initiates rapid eye movement sleep.

PubMed

Mallick, Birendra Nath; Singh, Abhishek; Khanday, Mudasir Ahmad

2012-06-01

Interactions among REM-ON and REM-OFF neurons form the basic scaffold for rapid eye movement sleep (REMS) regulation; however, precise mechanism of their activation and cessation, respectively, was unclear. Locus coeruleus (LC) noradrenalin (NA)-ergic neurons are REM-OFF type and receive GABA-ergic inputs among others. GABA acts postsynaptically on the NA-ergic REM-OFF neurons in the LC and presynaptically on the latter's projection terminals and modulates NA-release on the REM-ON neurons. Normally during wakefulness and non-REMS continuous release of NA from the REM-OFF neurons, which however, is reduced during the latter phase, inhibits the REM-ON neurons and prevents REMS. At this stage GABA from substantia nigra pars reticulate acting presynaptically on NA-ergic terminals on REM-ON neurons withdraws NA-release causing the REM-ON neurons to escape inhibition and being active, may be even momentarily. A working-model showing neurochemical-map explaining activation of inactivation process, showing contribution of GABA-ergic presynaptic inhibition in withdrawing NA-release and dis-inhibition induced activation of REM-ON neurons, which in turn activates other GABA-ergic neurons and shutting-off REM-OFF neurons for the initiation of REMS-generation has been explained. Our model satisfactorily explains yet unexplained puzzles (i) why normally REMS does not appear during waking, rather, appears following non-REMS; (ii) why cessation of LC-NA-ergic-REM-OFF neurons is essential for REMS-generation; (iii) factor(s) which does not allow cessation of REM-OFF neurons causes REMS-loss; (iv) the association of changes in levels of GABA and NA in the brain during REMS and its deprivation and associated symptoms; v) why often dreams are associated with REMS. Copyright © 2012 Elsevier Ltd. All rights reserved.

Rapid assessment of visual impairment (RAVI) in marine fishing communities in South India - study protocol and main findings

PubMed Central

2011-01-01

Background Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI) project. Methods A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA) was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was < 6/12 in either eye. Near vision was assessed using N notation chart binocularly. Visual impairment was defined as presenting VA < 6/18 in the better eye. Presbyopia is defined as binocular near vision worse than N8 in subjects with binocular distance VA of 6/18 or better. Results The data collection was completed in <12 weeks using two teams each consisting of one paramedical ophthalmic personnel and two community eye health workers. The prevalence of visual impairment was 30% (95% CI, 27.6-32.2). This included 111 (7.1%; 95% CI, 5.8-8.4) individuals with blindness. Cataract was the leading cause of visual impairment followed by uncorrected refractive errors. The prevalence of blindness according to WHO definition (presenting VA < 3/60 in the better eye) was 2.7% (95% CI, 1.9-3.5). Conclusion There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI) reported in this paper is robust, quick and has the potential to be replicated in other areas. PMID:21929802

Auditory Inhibition of Rapid Eye Movements and Dream Recall from REM Sleep

PubMed Central

Stuart, Katrina; Conduit, Russell

2009-01-01

Study Objectives: There is debate in dream research as to whether ponto-geniculo-occipital (PGO) waves or cortical arousal during sleep underlie the biological mechanisms of dreaming. This study comprised 2 experiments. As eye movements (EMs) are currently considered the best noninvasive indicator of PGO burst activity in humans, the aim of the first experiment was to investigate the effect of low-intensity repeated auditory stimulation on EMs (and inferred PGO burst activity) during REM sleep. It was predicted that such auditory stimuli during REM sleep would have a suppressive effect on EMs. The aim of the second experiment was to examine the effects of this auditory stimulation on subsequent dream reporting on awakening. Design: Repeated measures design with counterbalanced order of experimental and control conditions across participants. Setting: Sleep laboratory based polysomnography (PSG) Participants: Experiment 1: 5 males and 10 females aged 18-35 years (M = 20.8, SD = 5.4). Experiment 2: 7 males and 13 females aged 18-35 years (M = 23.3, SD = 5.5). Interventions: Below-waking threshold tone presentations during REM sleep compared to control REM sleep conditions without tone presentations. Measurements and Results: PSG records were manually scored for sleep stages, EEG arousals, and EMs. Auditory stimulation during REM sleep was related to: (a) an increase in EEG arousal, (b) a decrease in the amplitude and frequency of EMs, and (c) a decrease in the frequency of visual imagery reports on awakening. Conclusions: The results of this study provide phenomenological support for PGO-based theories of dream reporting on awakening from sleep in humans. Citation: Stuart K; Conduit R. Auditory inhibition of rapid eye movements and dream recall from REM sleep. SLEEP 2009;32(3):399–408. PMID:19294960

The Frequency of Rapid Pupil Dilations as a Measure of Linguistic Processing Difficulty

PubMed Central

Demberg, Vera; Sayeed, Asad

2016-01-01

While it has long been known that the pupil reacts to cognitive load, pupil size has received little attention in cognitive research because of its long latency and the difficulty of separating effects of cognitive load from the light reflex or effects due to eye movements. A novel measure, the Index of Cognitive Activity (ICA), relates cognitive effort to the frequency of small rapid dilations of the pupil. We report here on a total of seven experiments which test whether the ICA reliably indexes linguistically induced cognitive load: three experiments in reading (a manipulation of grammatical gender match / mismatch, an experiment of semantic fit, and an experiment comparing locally ambiguous subject versus object relative clauses, all in German), three dual-task experiments with simultaneous driving and spoken language comprehension (using the same manipulations as in the single-task reading experiments), and a visual world experiment comparing the processing of causal versus concessive discourse markers. These experiments are the first to investigate the effect and time course of the ICA in language processing. All of our experiments support the idea that the ICA indexes linguistic processing difficulty. The effects of our linguistic manipulations on the ICA are consistent for reading and auditory presentation. Furthermore, our experiments show that the ICA allows for usage within a multi-task paradigm. Its robustness with respect to eye movements means that it is a valid measure of processing difficulty for usage within the visual world paradigm, which will allow researchers to assess both visual attention and processing difficulty at the same time, using an eye-tracker. We argue that the ICA is indicative of activity in the locus caeruleus area of the brain stem, which has recently also been linked to P600 effects observed in psycholinguistic EEG experiments. PMID:26799065

Baseline Levels of Rapid Eye Movement Sleep May Protect Against Excessive Activity in Fear-Related Neural Circuitry.

PubMed

Lerner, Itamar; Lupkin, Shira M; Sinha, Neha; Tsai, Alan; Gluck, Mark A

2017-11-15

Sleep, and particularly rapid eye movement sleep (REM), has been implicated in the modulation of neural activity following fear conditioning and extinction in both human and animal studies. It has long been presumed that such effects play a role in the formation and persistence of posttraumatic stress disorder, of which sleep impairments are a core feature. However, to date, few studies have thoroughly examined the potential effects of sleep prior to conditioning on subsequent acquisition of fear learning in humans. Furthermore, these studies have been restricted to analyzing the effects of a single night of sleep-thus assuming a state-like relationship between the two. In the current study, we used long-term mobile sleep monitoring and functional neuroimaging (fMRI) to explore whether trait-like variations in sleep patterns, measured in advance in both male and female participants, predict subsequent patterns of neural activity during fear learning. Our results indicate that higher baseline levels of REM sleep predict reduced fear-related activity in, and connectivity between, the hippocampus, amygdala and ventromedial PFC during conditioning. Additionally, skin conductance responses (SCRs) were weakly correlated to the activity in the amygdala. Conversely, there was no direct correlation between REM sleep and SCRs, indicating that REM may only modulate fear acquisition indirectly. In a follow-up experiment, we show that these results are replicable, though to a lesser extent, when measuring sleep over a single night just before conditioning. As such, baseline sleep parameters may be able to serve as biomarkers for resilience, or lack thereof, to trauma. SIGNIFICANCE STATEMENT Numerous studies over the past two decades have established a clear role of sleep in fear-learning processes. However, previous work has focused on the effects of sleep following fear acquisition, thus neglecting the potential effects of baseline sleep levels on the acquisition itself. The current study provides the first evidence in humans of such an effect. Specifically, the results of this study suggest that baseline rapid eye movement (REM) sleep may serve a protective function against enhanced fear encoding through the modulation of connectivity between the hippocampus, amygdala, and the ventromedial PFC. Building on this finding, baseline REM measurements may serve as a noninvasive biomarker for resilience to trauma or, conversely, to the potential development of posttraumatic stress disorder following trauma. Copyright © 2017 the authors 0270-6474/17/3711233-12$15.00/0.

Interannual Change Detection of Mediterranean Seagrasses Using RapidEye Image Time Series

PubMed Central

Traganos, Dimosthenis; Reinartz, Peter

2018-01-01

Recent research studies have highlighted the decrease in the coverage of Mediterranean seagrasses due to mainly anthropogenic activities. The lack of data on the distribution of these significant aquatic plants complicates the quantification of their decreasing tendency. While Mediterranean seagrasses are declining, satellite remote sensing technology is growing at an unprecedented pace, resulting in a wealth of spaceborne image time series. Here, we exploit recent advances in high spatial resolution sensors and machine learning to study Mediterranean seagrasses. We process a multispectral RapidEye time series between 2011 and 2016 to detect interannual seagrass dynamics in 888 submerged hectares of the Thermaikos Gulf, NW Aegean Sea, Greece (eastern Mediterranean Sea). We assess the extent change of two Mediterranean seagrass species, the dominant Posidonia oceanica and Cymodocea nodosa, following atmospheric and analytical water column correction, as well as machine learning classification, using Random Forests, of the RapidEye time series. Prior corrections are necessary to untangle the initially weak signal of the submerged seagrass habitats from satellite imagery. The central results of this study show that P. oceanica seagrass area has declined by 4.1%, with a trend of −11.2 ha/yr, while C. nodosa seagrass area has increased by 17.7% with a trend of +18 ha/yr throughout the 5-year study period. Trends of change in spatial distribution of seagrasses in the Thermaikos Gulf site are in line with reported trends in the Mediterranean. Our presented methodology could be a time- and cost-effective method toward the quantitative ecological assessment of seagrass dynamics elsewhere in the future. From small meadows to whole coastlines, knowledge of aquatic plant dynamics could resolve decline or growth trends and accurately highlight key units for future restoration, management, and conservation. PMID:29467777

Interannual Change Detection of Mediterranean Seagrasses Using RapidEye Image Time Series.

PubMed

Traganos, Dimosthenis; Reinartz, Peter

2018-01-01

Recent research studies have highlighted the decrease in the coverage of Mediterranean seagrasses due to mainly anthropogenic activities. The lack of data on the distribution of these significant aquatic plants complicates the quantification of their decreasing tendency. While Mediterranean seagrasses are declining, satellite remote sensing technology is growing at an unprecedented pace, resulting in a wealth of spaceborne image time series. Here, we exploit recent advances in high spatial resolution sensors and machine learning to study Mediterranean seagrasses. We process a multispectral RapidEye time series between 2011 and 2016 to detect interannual seagrass dynamics in 888 submerged hectares of the Thermaikos Gulf, NW Aegean Sea, Greece (eastern Mediterranean Sea). We assess the extent change of two Mediterranean seagrass species, the dominant Posidonia oceanica and Cymodocea nodosa , following atmospheric and analytical water column correction, as well as machine learning classification, using Random Forests, of the RapidEye time series. Prior corrections are necessary to untangle the initially weak signal of the submerged seagrass habitats from satellite imagery. The central results of this study show that P. oceanica seagrass area has declined by 4.1%, with a trend of -11.2 ha/yr, while C. nodosa seagrass area has increased by 17.7% with a trend of +18 ha/yr throughout the 5-year study period. Trends of change in spatial distribution of seagrasses in the Thermaikos Gulf site are in line with reported trends in the Mediterranean. Our presented methodology could be a time- and cost-effective method toward the quantitative ecological assessment of seagrass dynamics elsewhere in the future. From small meadows to whole coastlines, knowledge of aquatic plant dynamics could resolve decline or growth trends and accurately highlight key units for future restoration, management, and conservation.

Evaluation of multi-resolution satellite sensors for assessing water quality and bottom depth of Lake Garda.

PubMed

Giardino, Claudia; Bresciani, Mariano; Cazzaniga, Ilaria; Schenk, Karin; Rieger, Patrizia; Braga, Federica; Matta, Erica; Brando, Vittorio E

2014-12-15

In this study we evaluate the capabilities of three satellite sensors for assessing water composition and bottom depth in Lake Garda, Italy. A consistent physics-based processing chain was applied to Moderate Resolution Imaging Spectroradiometer (MODIS), Landsat-8 Operational Land Imager (OLI) and RapidEye. Images gathered on 10 June 2014 were corrected for the atmospheric effects with the 6SV code. The computed remote sensing reflectance (Rrs) from MODIS and OLI were converted into water quality parameters by adopting a spectral inversion procedure based on a bio-optical model calibrated with optical properties of the lake. The same spectral inversion procedure was applied to RapidEye and to OLI data to map bottom depth. In situ measurements of Rrs and of concentrations of water quality parameters collected in five locations were used to evaluate the models. The bottom depth maps from OLI and RapidEye showed similar gradients up to 7 m (r = 0.72). The results indicate that: (1) the spatial and radiometric resolutions of OLI enabled mapping water constituents and bottom properties; (2) MODIS was appropriate for assessing water quality in the pelagic areas at a coarser spatial resolution; and (3) RapidEye had the capability to retrieve bottom depth at high spatial resolution. Future work should evaluate the performance of the three sensors in different bio-optical conditions.

Interaction and developmental activation of two neuroendocrine systems that regulate light-mediated skin pigmentation.

PubMed

Bertolesi, Gabriel E; Song, Yi N; Atkinson-Leadbeater, Karen; Yang, Jung-Lynn J; McFarlane, Sarah

2017-07-01

Lower vertebrates use rapid light-regulated changes in skin colour for camouflage (background adaptation) or during circadian variation in irradiance levels. Two neuroendocrine systems, the eye/alpha-melanocyte-stimulating hormone (α-MSH) and the pineal complex/melatonin circuits, regulate the process through their respective dispersion and aggregation of pigment granules (melanosomes) in skin melanophores. During development, Xenopus laevis tadpoles raised on a black background or in the dark perceive less light sensed by the eye and darken in response to increased α-MSH secretion. As embryogenesis proceeds, the pineal complex/melatonin circuit becomes the dominant regulator in the dark and induces lightening of the skin of larvae. The eye/α-MSH circuit continues to mediate darkening of embryos on a black background, but we propose the circuit is shut down in complete darkness in part by melatonin acting on receptors expressed by pituitary cells to inhibit the expression of pomc, the precursor of α-MSH. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Imaging in Diabetic Retinopathy: A Review of Current and Future Techniques.

PubMed

Gajree, Sonul; Borooah, Shyamanga; Dhillon, Baljean

2017-01-01

Diabetic eye disease is the most common cause of blindness worldwide in the population under 65 years of age. The prevalence of sight-threatening diabetic eye disease continues to rise rapidly, resulting in an increasing burden on health systems worldwide. This highlights the need to develop new tools to help in the screening, diagnosis and management of diabetic eye disease. This review aims to provide a brief overview of the current standard in care for diabetic eye disease, before providing an up to date overview of newer imaging modalities, with potential application in the management of diabetic eye care. A literature search for the terms "enhanced depth imaging OCT", "swept source OCT", "retinal oximetry", "OCT angiography", "fundus autofluorescence" with the term "diabetes" was performed using the pubmed and google scholar databases. Only articles published within the last two years were selected for use in this article. There has been a rapid increase in the available imaging techniques used to manage diabetic eye disease. To date there has been variable use of these next generation imaging techniques. A greater understanding of how phenotypic findings link to the risk of sight loss is required before there is more widespread adoption by mainstream diabetic eye services. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A high-resolution 3D ultrasonic system for rapid evaluation of the anterior and posterior segment.

PubMed

Peyman, Gholam A; Ingram, Charles P; Montilla, Leonardo G; Witte, Russell S

2012-01-01

Traditional ultrasound imaging systems for ophthalmology employ slow, mechanical scanning of a single-element ultrasound transducer. The goal was to demonstrate rapid examination of the anterior and posterior segment with a three-dimensional (3D) commercial ultrasound system incorporating high-resolution linear probe arrays. The 3D images of the porcine eye were generated in approximately 10 seconds by scanning one of two commercial linear arrays (25- and 50-MHz). Healthy enucleated pig eyes were compared with those with induced injury or placement of a foreign material (eg, metal). Rapid, volumetric imaging was also demonstrated in one human eye in vivo. The 50-MHz probe provided exquisite volumetric images of the anterior segment at a depth up to 15 mm and axial resolution of 30 μm. The 25-MHz probe provided a larger field of view (lateral X depth: 20 × 30 mm), sufficient for capturing the entire anterior and posterior segments of the pig eye, at a resolution of 60 μm. A 50-MHz scan through the human eyelid illustrated detailed structures of the Meibomian glands, cilia, cornea, and anterior segment back to the posterior capsule. The 3D system with its high-frequency ultrasound arrays, fast data acquisition, and volume rendering capability shows promise for investigating anterior and posterior structures of the eye. Copyright 2012, SLACK Incorporated.

Endogenous excitatory drive to the respiratory system in rapid eye movement sleep in cats.

PubMed

Orem, J; Lovering, A T; Dunin-Barkowski, W; Vidruk, E H

2000-09-01

A putative endogenous excitatory drive to the respiratory system in rapid eye movement (REM) sleep may explain many characteristics of breathing in that state, e.g. its irregularity and variable ventilatory responses to chemical stimuli. This drive is hypothetical, and determinations of its existence and character are complicated by control of the respiratory system by the oscillator and its feedback mechanisms. In the present study, endogenous drive was studied during apnoea caused by mechanical hyperventilation. We reasoned that if there was a REM-dependent drive to the respiratory system, then respiratory activity should emerge out of the background apnoea as a manifestation of the drive. Diaphragmatic muscle or medullary respiratory neuronal activity was studied in five intact, unanaesthetized adult cats who were either mechanically hyperventilated or breathed spontaneously in more than 100 REM sleep periods. Diaphragmatic activity emerged out of a background apnoea caused by mechanical hyperventilation an average of 34 s after the onset of REM sleep. Emergent activity occurred in 60 % of 10 s epochs in REM sleep and the amount of activity per unit time averaged approximately 40 % of eupnoeic activity. The activity occurred in episodes and was poorly related to pontogeniculo-occipital waves. At low CO2 levels, this activity was non-rhythmic. At higher CO2 levels (less than 0.5 % below eupnoeic end-tidal percentage CO2 levels in non-REM (NREM) sleep), activity became rhythmic. Medullary respiratory neurons were recorded in one of the five animals. Nineteen of twenty-seven medullary respiratory neurons were excited in REM sleep during apnoea. Excited neurons included inspiratory, expiratory and phase-spanning neurons. Excitation began about 43 s after the onset of REM sleep. Activity increased from an average of 6 impulses s-1 in NREM sleep to 15.5 impulses s-1 in REM sleep. Neuronal activity was non-rhythmic at low CO2 levels and became rhythmic when levels were less than 0.5 % below eupnoeic end-tidal levels in NREM sleep. The level of CO2 at which rhythmic neuronal activity developed corresponded to eupnoeic end-tidal CO2 levels in REM sleep. These results demonstrate an endogenous excitatory drive to the respiratory system in REM sleep and account for rapid and irregular breathing and the lower set-point to CO2 in that state.

Biomechanical Changes After LASIK Flap Creation Combined With Rapid Cross-Linking Measured With Brillouin Microscopy.

PubMed

Randleman, J Bradley; Su, Johnny P; Scarcelli, Giuliano

2017-06-01

To evaluate the biomechanical changes occurring after LASIK flap creation and rapid corneal cross-linking (CXL) measured with Brillouin light microscopy. Porcine eyes (n = 11) were evaluated by Brillouin light microscopy sequentially in the following order: virgin state, after LASIK flap creation, and after rapid CXL. Each eye served as its own control. Depth profile of the Brillouin frequency shift was computed to reveal the depth-dependent changes in corneal stiffness. There was a statistically significant reduction of Brillouin shift (reduced corneal stiffness) after LASIK flap creation compared to virgin corneas across total corneal thickness (-0.035 GHz, P = .0195) and within the anterior stromal region (-0.104 GHz, P = .0039). Changes in the central (-0.029 GHz, P = .0391) and posterior (-0.005 GHz, P = .99) stromal regions were not significant. There was a small increase in Brillouin shift after rapid cross-linking that was not statistically or clinically significant across total corneal thickness (0.006 GHz, P = .4688 for any specific stromal region; 0.002 to 0.009 GHz, P > .46 for all). LASIK flap creation significantly reduced Brillouin shift in the anterior third of the stroma in porcine eyes. Rapid corneal cross-linking had no significant effect on Brillouin shift after LASIK flap creation in porcine eyes. With further validation, non-contact, non-perturbative Brillouin microscopy could become a useful monitoring tool to evaluate the biomechanical impact of corneal refractive procedures and corneal cross-linking protocols. [J Refract Surg. 2017;33(6):408-414.]. Copyright 2017, SLACK Incorporated.

Quantitative electroencephalography during rapid eye movement (REM) and non-REM sleep in combat-exposed veterans with and without post-traumatic stress disorder.

PubMed

Cohen, Daniel J; Begley, Amy; Alman, Jennie J; Cashmere, David J; Pietrone, Regina N; Seres, Robert J; Germain, Anne

2013-02-01

Sleep disturbances are a hallmark feature of post-traumatic stress disorder (PTSD), and associated with poor clinical outcomes. Few studies have examined sleep quantitative electroencephalography (qEEG), a technique able to detect subtle differences that polysomnography does not capture. We hypothesized that greater high-frequency qEEG would reflect 'hyperarousal' in combat veterans with PTSD (n = 16) compared to veterans without PTSD (n = 13). EEG power in traditional EEG frequency bands was computed for artifact-free sleep epochs across an entire night. Correlations were performed between qEEG and ratings of PTSD symptoms and combat exposure. The groups did not differ significantly in whole-night qEEG measures for either rapid eye movement (REM) or non-REM (NREM) sleep. Non-significant medium effect sizes suggest less REM beta (opposite to our hypothesis), less REM and NREM sigma and more NREM gamma in combat veterans with PTSD. Positive correlations were found between combat exposure and NREM beta (PTSD group only), and REM and NREM sigma (non-PTSD group only). Results did not support global hyperarousal in PTSD as indexed by increased beta qEEG activity. The correlation of sigma activity with combat exposure in those without PTSD and the non-significant trend towards less sigma activity during both REM and NREM sleep in combat veterans with PTSD suggests that differential information processing during sleep may characterize combat-exposed military veterans with and without PTSD. © 2012 European Sleep Research Society.

Theta and gamma coordination of hippocampal networks during waking and rapid eye movement sleep.

PubMed

Montgomery, Sean M; Sirota, Anton; Buzsáki, György

2008-06-25

Rapid eye movement (REM) sleep has been considered a paradoxical state because, despite the high behavioral threshold to arousing perturbations, gross physiological patterns in the forebrain resemble those of waking states. To understand how intrahippocampal networks interact during REM sleep, we used 96 site silicon probes to record from different hippocampal subregions and compared the patterns of activity during waking exploration and REM sleep. Dentate/CA3 theta and gamma synchrony was significantly higher during REM sleep compared with active waking. In contrast, gamma power in CA1 and CA3-CA1 gamma coherence showed significant decreases in REM sleep. Changes in unit firing rhythmicity and unit-field coherence specified the local generation of these patterns. Although these patterns of hippocampal network coordination characterized the more common tonic periods of REM sleep (approximately 95% of total REM), we also detected large phasic bursts of local field potential power in the dentate molecular layer that were accompanied by transient increases in the firing of dentate and CA1 neurons. In contrast to tonic REM periods, phasic REM epochs were characterized by higher theta and gamma synchrony among the dentate, CA3, and CA1 regions. These data suggest enhanced dentate processing, but limited CA3-CA1 coordination during tonic REM sleep. In contrast, phasic bursts of activity during REM sleep may provide windows of opportunity to synchronize the hippocampal trisynaptic loop and increase output to cortical targets. We hypothesize that tonic REM sleep may support off-line mnemonic processing, whereas phasic bursts of activity during REM may promote memory consolidation.

Advanced multiphoton methods for in vitro and in vivo functional imaging of mouse retinal neurons (Conference Presentation)

NASA Astrophysics Data System (ADS)

Cohen, Noam; Schejter, Adi; Farah, Nairouz; Shoham, Shy

2016-03-01

Studying the responses of retinal ganglion cell (RGC) populations has major significance in vision research. Multiphoton imaging of optogenetic probes has recently become the leading approach for visualizing neural populations and has specific advantages for imaging retinal activity during visual stimulation, because it leads to reduced direct photoreceptor excitation. However, multiphoton retinal activity imaging is not straightforward: point-by-point scanning leads to repeated neural excitation while optical access through the rodent eye in vivo has proven highly challenging. Here, we present two enabling optical designs for multiphoton imaging of responses to visual stimuli in mouse retinas expressing calcium indicators. First, we present an imaging solution based on Scanning Line Temporal Focusing (SLITE) for rapidly imaging neuronal activity in vitro. In this design, we scan a temporally focused line rather than a point, increasing the scan speed and reducing the impact of repeated excitation, while maintaining high optical sectioning. Second, we present the first in vivo demonstration of two-photon imaging of RGC activity in the mouse retina. To obtain these cellular resolution recordings we integrated an illumination path into a correction-free imaging system designed using an optical model of the mouse eye. This system can image at multiple depths using an electronically tunable lens integrated into its optical path. The new optical designs presented here overcome a number of outstanding obstacles, allowing the study of rapid calcium- and potentially even voltage-indicator signals both in vitro and in vivo, thereby bringing us a step closer toward distributed monitoring of action potentials.

Assessment of RapidEye vegetation indices for estimation of leaf area index and biomass in corn and soybean crops

NASA Astrophysics Data System (ADS)

Kross, Angela; McNairn, Heather; Lapen, David; Sunohara, Mark; Champagne, Catherine

2015-02-01

Leaf area index (LAI) and biomass are important indicators of crop development and the availability of this information during the growing season can support farmer decision making processes. This study demonstrates the applicability of RapidEye multi-spectral data for estimation of LAI and biomass of two crop types (corn and soybean) with different canopy structure, leaf structure and photosynthetic pathways. The advantages of Rapid Eye in terms of increased temporal resolution (∼daily), high spatial resolution (∼5 m) and enhanced spectral information (includes red-edge band) are explored as an individual sensor and as part of a multi-sensor constellation. Seven vegetation indices based on combinations of reflectance in green, red, red-edge and near infrared bands were derived from RapidEye imagery between 2011 and 2013. LAI and biomass data were collected during the same period for calibration and validation of the relationships between vegetation indices and LAI and dry above-ground biomass. Most indices showed sensitivity to LAI from emergence to 8 m2/m2. The normalized difference vegetation index (NDVI), the red-edge NDVI and the green NDVI were insensitive to crop type and had coefficients of variations (CV) ranging between 19 and 27%; and coefficients of determination ranging between 86 and 88%. The NDVI performed best for the estimation of dry leaf biomass (CV = 27% and r2 = 090) and was also insensitive to crop type. The red-edge indices did not show any significant improvement in LAI and biomass estimation over traditional multispectral indices. Cumulative vegetation indices showed strong performance for estimation of total dry above-ground biomass, especially for corn (CV ≤ 20%). This study demonstrated that continuous crop LAI monitoring over time and space at the field level can be achieved using a combination of RapidEye, Landsat and SPOT data and sensor-dependant best-fit functions. This approach eliminates/reduces the need for reflectance resampling, VIs inter-calibration and spatial resampling.

Fragmentation of Rapid Eye Movement and Nonrapid Eye Movement Sleep without Total Sleep Loss Impairs Hippocampus-Dependent Fear Memory Consolidation.

PubMed

Lee, Michael L; Katsuyama, Ângela M; Duge, Leanne S; Sriram, Chaitra; Krushelnytskyy, Mykhaylo; Kim, Jeansok J; de la Iglesia, Horacio O

2016-11-01

Sleep is important for consolidation of hippocampus-dependent memories. It is hypothesized that the temporal sequence of nonrapid eye movement (NREM) sleep and rapid eye movement (REM) sleep is critical for the weakening of nonadaptive memories and the subsequent transfer of memories temporarily stored in the hippocampus to more permanent memories in the neocortex. A great body of evidence supporting this hypothesis relies on behavioral, pharmacological, neural, and/or genetic manipulations that induce sleep deprivation or stage-specific sleep deprivation. We exploit an experimental model of circadian desynchrony in which intact animals are not deprived of any sleep stage but show fragmentation of REM and NREM sleep within nonfragmented sleep bouts. We test the hypothesis that the shortening of NREM and REM sleep durations post-training will impair memory consolidation irrespective of total sleep duration. When circadian-desynchronized animals are trained in a hippocampus-dependent contextual fear-conditioning task they show normal short-term memory but impaired long-term memory consolidation. This impairment in memory consolidation is positively associated with the post-training fragmentation of REM and NREM sleep but is not significantly associated with the fragmentation of total sleep or the total amount of delta activity. We also show that the sleep stage fragmentation resulting from circadian desynchrony has no effect on hippocampus-dependent spatial memory and no effect on hippocampus-independent cued fear-conditioning memory. Our findings in an intact animal model, in which sleep deprivation is not a confounding factor, support the hypothesis that the stereotypic sequence and duration of sleep stages play a specific role in long-term hippocampus-dependent fear memory consolidation. © 2016 Associated Professional Sleep Societies, LLC.

The golden age of rapid eye movement sleep discoveries. 1. Lucretius--1964.

PubMed

Gottesmann, C

2001-10-01

Although there were several premonitory signs of a sleep stage with dreaming, it was only in 1953 that such a stage was identified with certainty. This paper analyses the observations and research related to this dreaming stage (rapid eye movement sleep) until 1964. During these 11 years of research, the main psychological and physiological characteristics of this sleep stage were first described. Where the few results or discussions were later questioned, today's current state of knowledge is briefly outlined.

Rapid Simultaneous Enhancement of Visual Sensitivity and Perceived Contrast during Saccade Preparation

PubMed Central

Rolfs, Martin; Carrasco, Marisa

2012-01-01

Humans and other animals with foveate vision make saccadic eye movements to prioritize the visual analysis of behaviorally relevant information. Even before movement onset, visual processing is selectively enhanced at the target of a saccade, presumably gated by brain areas controlling eye movements. Here we assess concurrent changes in visual performance and perceived contrast before saccades, and show that saccade preparation enhances perception rapidly, altering early visual processing in a manner akin to increasing the physical contrast of the visual input. Observers compared orientation and contrast of a test stimulus, appearing briefly before a saccade, to a standard stimulus, presented previously during a fixation period. We found simultaneous progressive enhancement in both orientation discrimination performance and perceived contrast as time approached saccade onset. These effects were robust as early as 60 ms after the eye movement was cued, much faster than the voluntary deployment of covert attention (without eye movements), which takes ~300 ms. Our results link the dynamics of saccade preparation, visual performance, and subjective experience and show that upcoming eye movements alter visual processing by increasing the signal strength. PMID:23035086

Strength training, walking, and social activity improve sleep in nursing home and assisted living residents: randomized controlled trial.

PubMed

Richards, Kathy C; Lambert, Corinne; Beck, Cornelia K; Bliwise, Donald L; Evans, William J; Kalra, Gurpreet K; Kleban, Morton H; Lorenz, Rebecca; Rose, Karen; Gooneratne, Nalaka S; Sullivan, Dennis H

2011-02-01

To compare the effects of physical resistance strength training and walking (E), individualized social activity (SA), and E and SA (ESA) with a usual care control group on total nocturnal sleep time in nursing home and assisted living residents. Pretest-posttest experimental design with assignment to one of four groups for 7 weeks: E (n=55), SA (n=50), ESA (n=41), and usual care control (n=47). Ten nursing homes and three assisted living facilities. One hundred ninety-three residents were randomly assigned; 165 completed the study. The E group participated in high-intensity physical resistance strength training 3 days a week and on 2 days walked for up to 45 minutes, the SA group received social activity 1 hour daily 5 days a week, the ESA group received both E and SA, and the control group participated in usual activities provided in the homes. Total nocturnal sleep time was measured using 2 nights of polysomnography before and 2 nights of polysomnography after the intervention. Sleep efficiency (SE), non-rapid eye movement (NREM) sleep, rapid eye movement sleep, and sleep onset latency were also analyzed. Total nocturnal sleep time was significantly greater in the ESA group than in the control group (adjusted means 364.2 minutes vs 328.9 minutes), as was SE and NREM sleep. High-intensity physical resistance strength training and walking combined with social activity significantly improved sleep in nursing home and assisted living residents. The interventions by themselves did not have significant effects on sleep in this population. © 2011, Copyright the Authors. Journal compilation © 2011, The American Geriatrics Society.

Retrospective Study Evaluating Treatment Decisions and Outcomes of Childhood Uveitis Not Associated with Juvenile Idiopathic Arthritis.

PubMed

Sardar, Elham; Dusser, Perrine; Rousseau, Antoine; Bodaghi, Bahram; Labetoulle, Marc; Koné-Paut, Isabelle

2017-07-01

To evaluate treatment, ocular complications and outcomes of children with pediatric uveitis not associated with juvenile idiopathic arthritis. This was a retrospective chart review of pediatric uveitis in children under 16 years of age, recruited from the pediatric rheumatology department at Bicêtre Hospital from 2005 to 2015. Patients with juvenile idiopathic arthritis-associated and infectious uveitis were excluded. We used the Standardization of Uveitis Nomenclature Working Group to classify uveitis, disease activity, and treatment end points. We enrolled 56 patients and 102 affected eyes. The mean age at diagnosis was 10 ± 3.5 years (range 3-15), and the mean follow-up 4.2 ± 3.3 years (1-15). The main diagnoses were idiopathic (55%), Behçet disease (15%), and sarcoidosis (5%). The main localization was panuveitis in 44 of 102 eyes (43%). Corticosteroid sparing treatment was needed in 62 of 102 eyes (60%). Second-line therapies included methotrexate and azathioprine, and the third-line therapy was a biologic agent, mainly infliximab, in 33 of 102 eyes (32%). Infliximab achieved uveitis inactivity in 14 of 18 eyes (80%), in all etiologies. Severe complications were present in 68 of 102 eyes (67%). The most common were synechiae 33% of eyes, cataract (20%), and macular edema (25%). Of these, 37% were present at diagnosis. Remission was achieved in 22 of 102 eyes (21%). Conventional therapies were insufficient to treat many of the cases of posterior or panuveitis. This study underlines the need for earlier and more aggressive treatment and antitumor necrosis factor-α therapy was rapidly efficient in most cases of refractory uveitis. Copyright © 2017 Elsevier Inc. All rights reserved.

Malathion poisoning

MedlinePlus

... AND KIDNEYS Increased urination Inability to control urine flow (incontinence) EYES, EARS, NOSE, AND THROAT Increased salivation Increased tears in the eyes Small or dilated pupils that do not react to light HEART AND BLOOD Low or high blood pressure Slow or rapid heart rate Weakness ...

Regression-Based Identification of Behavior-Encoding Neurons During Large-Scale Optical Imaging of Neural Activity at Cellular Resolution

PubMed Central

Miri, Andrew; Daie, Kayvon; Burdine, Rebecca D.; Aksay, Emre

2011-01-01

The advent of methods for optical imaging of large-scale neural activity at cellular resolution in behaving animals presents the problem of identifying behavior-encoding cells within the resulting image time series. Rapid and precise identification of cells with particular neural encoding would facilitate targeted activity measurements and perturbations useful in characterizing the operating principles of neural circuits. Here we report a regression-based approach to semiautomatically identify neurons that is based on the correlation of fluorescence time series with quantitative measurements of behavior. The approach is illustrated with a novel preparation allowing synchronous eye tracking and two-photon laser scanning fluorescence imaging of calcium changes in populations of hindbrain neurons during spontaneous eye movement in the larval zebrafish. Putative velocity-to-position oculomotor integrator neurons were identified that showed a broad spatial distribution and diversity of encoding. Optical identification of integrator neurons was confirmed with targeted loose-patch electrical recording and laser ablation. The general regression-based approach we demonstrate should be widely applicable to calcium imaging time series in behaving animals. PMID:21084686

BK Channels Are Required for Multisensory Plasticity in the Oculomotor System.

PubMed

Nelson, Alexandra B; Faulstich, Michael; Moghadam, Setareh; Onori, Kimberly; Meredith, Andrea; du Lac, Sascha

2017-01-04

Neural circuits are endowed with several forms of intrinsic and synaptic plasticity that could contribute to adaptive changes in behavior, but circuit complexities have hindered linking specific cellular mechanisms with their behavioral consequences. Eye movements generated by simple brainstem circuits provide a means for relating cellular plasticity to behavioral gain control. Here we show that firing rate potentiation, a form of intrinsic plasticity mediated by reductions in BK-type calcium-activated potassium currents in spontaneously firing neurons, is engaged during optokinetic reflex compensation for inner ear dysfunction. Vestibular loss triggers transient increases in postsynaptic excitability, occlusion of firing rate potentiation, and reductions in BK currents in vestibular nucleus neurons. Concurrently, adaptive increases in visually evoked eye movements rapidly restore oculomotor function in wild-type mice but are profoundly impaired in BK channel-null mice. Activity-dependent regulation of intrinsic excitability may be a general mechanism for adaptive control of behavioral output in multisensory circuits. Copyright © 2017 Elsevier Inc. All rights reserved.

Mobile phones and sleep - A review

NASA Astrophysics Data System (ADS)

Supe, Sanjay S.

2010-01-01

The increasing use of mobile phones has raised concerns regarding the potential health effects of exposure to the radiofrequency electromagnetic fields. An increasing amount research related to mobile phone use has focussed on the possible effects of mobile phone exposure on human brain activity and function. In particular, the use of sleep research has become a more widely used technique for assessing the possible effects of mobile phones on human health and wellbeing especially in the investigation of potential changes in sleep architecture resulting from mobile phone use. Acute exposure to a mobile phone prior to sleep significantly enhances electroencephalogram spectral power in the sleep spindle frequency range. This mobile phone-induced enhancement in spectral power is largely transitory and does not linger throughout the night. Furthermore, a reduction in rapid eye movement sleep latency following mobile phone exposure was also found, although interestingly, neither this change in rapid eye movement sleep latency or the enhancement in spectral power following mobile phone exposure, led to changes in the overall quality of sleep. In conclusion, a short exposure to the radiofrequency electromagnetic fields emitted by a mobile phone handset immediately prior to sleep is sufficient to induce changes in brain activity in the initial part of sleep. The consequences or functional significance of this effect are currently unknown and it would be premature to draw conclusions about possible health consequences.

Nonlinear analysis of heart rate variability within independent frequency components during the sleep-wake cycle.

PubMed

Vigo, Daniel E; Dominguez, Javier; Guinjoan, Salvador M; Scaramal, Mariano; Ruffa, Eduardo; Solernó, Juan; Siri, Leonardo Nicola; Cardinali, Daniel P

2010-04-19

Heart rate variability (HRV) is a complex signal that results from the contribution of different sources of oscillation related to the autonomic nervous system activity. Although linear analysis of HRV has been applied to sleep studies, the nonlinear dynamics of HRV underlying frequency components during sleep is less known. We conducted a study to evaluate nonlinear HRV within independent frequency components in wake status, slow-wave sleep (SWS, stages III or IV of non-rapid eye movement sleep), and rapid-eye-movement sleep (REM). The sample included 10 healthy adults. Polysomnography was performed to detect sleep stages. HRV was studied globally during each phase and then very low frequency (VLF), low frequency (LF) and high frequency (HF) components were separated by means of the wavelet transform algorithm. HRV nonlinear dynamics was estimated with sample entropy (SampEn). A higher SampEn was found when analyzing global variability (Wake: 1.53+/-0.28, SWS: 1.76+/-0.32, REM: 1.45+/-0.19, p=0.005) and VLF variability (Wake: 0.13+/-0.03, SWS: 0.19+/-0.03, REM: 0.14+/-0.03, p<0.001) at SWS. REM was similar to wake status regarding nonlinear HRV. We propose nonlinear HRV is a useful index of the autonomic activity that characterizes the different sleep-wake cycle stages. 2009 Elsevier B.V. All rights reserved.

Effects of some antipsychotics and a benzodiazepine hypnotic on the sleep-wake pattern in an animal model of schizophrenia.

PubMed

Ishida, Takayuki; Obara, Yoshihito; Kamei, Chiaki

2009-09-01

We studied the effects of antipsychotics and a hypnotic on sleep disturbance in schizophrenia using an animal model of the disease. Electrodes for the electroencephalogram (EEG) and electromyogram (EMG) were chronically implanted into the cortex and the dorsal neck muscle of rats. EEG and EMG were recorded with an electroencephalograph for 6 h (10:00 - 16:00). SleepSign ver. 2.0 was used for EEG and EMG analysis. Haloperidol and olanzapine had an antagonizing effect on the increases in sleep latency and total awake time and the decrease in total non-rapid eye movement (NREM) sleep time induced by MK-801. Olanzapine also antagonized the decrease in total rapid eye movement (REM) sleep time induced by MK-801. Aripiprazole antagonized only the increase in sleep latency induced by MK-801, whereas, risperidone, quetiapine, and flunitrazepam had no effect in the changes of sleep-wake pattern induced by MK-801. Olanzapine increased delta activity and decreased beta activity during NREM sleep. In contrast, flunitrazepam had an opposite effect. It was clarified that haloperidol and olanzapine were effective for decrease of sleep time in this animal model of schizophrenia. In addition, aripiprazole showed a sleep-inducing effect in schizophrenia model rat. On the other hand, flunitrazepam showed no beneficial effect on sleep disturbance in schizophrenia model rat.

Familial exudative vitreoretinopathy mimicking persistent hyperplastic primary vitreous.

PubMed

Chang-Godinich, A; Paysse, E A; Coats, D K; Holz, E R

1999-04-01

To report an unusual case of familial exudative vitreoretinopathy in an infant. Case report. A 6-day-old girl had unilateral microphthalmia in the right eye, with a retrolental plaque initially diagnosed as persistent hyperplastic primary vitreous. Three months later, peripheral retinal vascular changes and a fibrovascular ridge were noted in the left eye, suggesting familial exudative vitreoretinopathy as the cause in both eyes. The microphthalmic right eye was unsalvageable. The left eye developed an exudative retinal detachment despite photocoagulation of the peripheral avascular retina. Additional cryotherapy resulted in resolution of the detachment and regression of the vascular changes. With highly asymmetric involvement, neonatal familial exudative vitreoretinopathy can mimic persistent hyperplastic primary vitreous. Fellow eye involvement can progress rapidly.

Gray matter abnormalities of the dorsal posterior cingulate in sleep walking.

PubMed

Heidbreder, Anna; Stefani, Ambra; Brandauer, Elisabeth; Steiger, Ruth; Kremser, Christian; Gizewski, Elke R; Young, Peter; Poewe, Werner; Högl, Birgit; Scherfler, Christoph

2017-08-01

This study aimed to determine whether voxel-based analysis of T1 weighted magnetic resonance imaging (MRI) and diffusion tensor imaging is able to detect alterations of gray and white matter morphometry as well as measures of mean diffusivity and fractional anisotropy in patients with non-rapid eye movement parasomnia. 3 Tesla MRI was performed in 14 drug-free, polysomnography-confirmed adult patients with non-rapid eye movement parasomnia (age: 29 ± 4.2 years; disease duration 19.2 ± 7.7 years) and 14 healthy subjects, matched for age and gender. Statistical parametric mapping was applied to objectively identify focal changes of MRI parameters throughout the entire brain volume. Statistical parametric mapping localized significant decreases of gray matter volume in the left dorsal posterior cingulate cortex (BA23) and posterior midcingulate cortex (BA24) in patients with non-rapid eye movement parasomnias compared to the control group (p < 0.001, corrected for multiple comparisons). No significant differences of mean diffusivity and fractional anisotropy measures were found between the non-rapid eye movement parasomnia group and the healthy control group. Recently, the simultaneous co-existence of arousal or wakefulness originating from the motor and cingulate cortices and persistent sleep in associative cortical regions was suggested as a functional framework of somnambulism. Gray matter volume decline in the dorsal posterior and posterior midcingulate cortex reported in this study might represent the neuroanatomical substrate for this condition. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of gravity on vertical eye position.

PubMed

Pierrot-Deseilligny, C

2009-05-01

There is growing evidence that gravity markedly influences vertical eye position and movements. A new model for the organization of brainstem upgaze pathways is presented in this review. The crossing ventral tegmental tract (CVTT) could be the efferent tract of an "antigravitational" pathway terminating at the elevator muscle motoneurons in the third nerve nuclei and comprising, upstream, the superior vestibular nucleus and y-group, the flocculus, and the otoliths. This pathway functions in parallel to the medial longitudinal fasciculus pathways, which control vertical eye movements made to compensate for all vertical head movements and may also comprise the "gravitational" vestibular pathways, involved in the central reflection of the gravity effect. The CVTT could provide the upgaze system with the supplement of tonic activity required to counteract the gravity effect expressed in the gravitational pathway, being permanently modulated according to the static positions of the head (i.e., the instantaneous gravity vector) between a maximal activity in the upright position and a minimal activity in horizontal positions. Different types of arguments support this new model. The permanent influence of gravity on vertical eye position is strongly suggested by the vertical slow phases and nystagmus observed after rapid changes in hypo- or hypergravity. The chin-beating nystagmus, existing in normal subjects with their head in the upside-down position, suggests that gravity is not compensated for in the downgaze system. Upbeat nystagmus due to brainstem lesions, most likely affecting the CVTT circuitry, is improved when the head is in the horizontal position, suggesting that this circuitry is involved in the counteraction of gravity between the upright and horizontal positions of the head. In downbeat nystagmus due to floccular damage, in which a permanent hyperexcitation of the CVTT could exist, a marked influence of static positions of the head is also observed. Finally, the strongest argument supporting a marked role of gravity in vertical eye position is that the eye movement alterations observed in the main, typical physiological and pathological conditions are precisely those that would be expected from a direct effect of gravity on the eyeballs, with, moreover, no single alternative interpretation existing so far that could account for all these different types of findings.

Spatial updating in area LIP is independent of saccade direction.

PubMed

Heiser, Laura M; Colby, Carol L

2006-05-01

We explore the world around us by making rapid eye movements to objects of interest. Remarkably, these eye movements go unnoticed, and we perceive the world as stable. Spatial updating is one of the neural mechanisms that contributes to this perception of spatial constancy. Previous studies in macaque lateral intraparietal cortex (area LIP) have shown that individual neurons update, or "remap," the locations of salient visual stimuli at the time of an eye movement. The existence of remapping implies that neurons have access to visual information from regions far beyond the classically defined receptive field. We hypothesized that neurons have access to information located anywhere in the visual field. We tested this by recording the activity of LIP neurons while systematically varying the direction in which a stimulus location must be updated. Our primary finding is that individual neurons remap stimulus traces in multiple directions, indicating that LIP neurons have access to information throughout the visual field. At the population level, stimulus traces are updated in conjunction with all saccade directions, even when we consider direction as a function of receptive field location. These results show that spatial updating in LIP is effectively independent of saccade direction. Our findings support the hypothesis that the activity of LIP neurons contributes to the maintenance of spatial constancy throughout the visual field.

Rapid, Accurate, and Non-Invasive Measurement of Zebrafish Axial Length and Other Eye Dimensions Using SD-OCT Allows Longitudinal Analysis of Myopia and Emmetropization

PubMed Central

Collery, Ross F.; Veth, Kerry N.; Dubis, Adam M.; Carroll, Joseph; Link, Brian A.

2014-01-01

Refractive errors in vision can be caused by aberrant axial length of the eye, irregular corneal shape, or lens abnormalities. Causes of eye length overgrowth include multiple genetic loci, and visual parameters. We evaluate zebrafish as a potential animal model for studies of the genetic, cellular, and signaling basis of emmetropization and myopia. Axial length and other eye dimensions of zebrafish were measured using spectral domain-optical coherence tomography (SD-OCT). We used ocular lens and body metrics to normalize and compare eye size and relative refractive error (difference between observed retinal radial length and controls) in wild-type and lrp2 zebrafish. Zebrafish were dark-reared to assess effects of visual deprivation on eye size. Two relative measurements, ocular axial length to body length and axial length to lens diameter, were found to accurately normalize comparisons of eye sizes between different sized fish (R2 = 0.9548, R2 = 0.9921). Ray-traced focal lengths of wild-type zebrafish lenses were equal to their retinal radii, while lrp2 eyes had longer retinal radii than focal lengths. Both genetic mutation (lrp2) and environmental manipulation (dark-rearing) caused elongated eye axes. lrp2 mutants had relative refractive errors of −0.327 compared to wild-types, and dark-reared wild-type fish had relative refractive errors of −0.132 compared to light-reared siblings. Therefore, zebrafish eye anatomy (axial length, lens radius, retinal radius) can be rapidly and accurately measured by SD-OCT, facilitating longitudinal studies of regulated eye growth and emmetropization. Specifically, genes homologous to human myopia candidates may be modified, inactivated or overexpressed in zebrafish, and myopia-sensitizing conditions used to probe gene-environment interactions. Our studies provide foundation for such investigations into genetic contributions that control eye size and impact refractive errors. PMID:25334040

Development of Methods for the Real-Time and Rapid Identification and Detection of TSE in Living Animals Using Fluorescence Spectroscopy of the Eye

DTIC Science & Technology

2005-07-01

and cow eyes and performed fluorescence spectroscopy on all the major eye components and reports that the cornea, lens, retina , and optic nerve show...appears that while the optic nerve presents the richest spectra with the most detail, the retina is the most promising target for use as a probe. This... retinas is striking and is illustrated in Figure 1. • Preliminary data of total eye fluorescence from mice as a function of age are presented

Neural control of visual search by frontal eye field: effects of unexpected target displacement on visual selection and saccade preparation.

PubMed

Murthy, Aditya; Ray, Supriya; Shorter, Stephanie M; Schall, Jeffrey D; Thompson, Kirk G

2009-05-01

The dynamics of visual selection and saccade preparation by the frontal eye field was investigated in macaque monkeys performing a search-step task combining the classic double-step saccade task with visual search. Reward was earned for producing a saccade to a color singleton. On random trials the target and one distractor swapped locations before the saccade and monkeys were rewarded for shifting gaze to the new singleton location. A race model accounts for the probabilities and latencies of saccades to the initial and final singleton locations and provides a measure of the duration of a covert compensation process-target-step reaction time. When the target stepped out of a movement field, noncompensated saccades to the original location were produced when movement-related activity grew rapidly to a threshold. Compensated saccades to the final location were produced when the growth of the original movement-related activity was interrupted within target-step reaction time and was replaced by activation of other neurons producing the compensated saccade. When the target stepped into a receptive field, visual neurons selected the new target location regardless of the monkeys' response. When the target stepped out of a receptive field most visual neurons maintained the representation of the original target location, but a minority of visual neurons showed reduced activity. Chronometric analyses of the neural responses to the target step revealed that the modulation of visually responsive neurons and movement-related neurons occurred early enough to shift attention and saccade preparation from the old to the new target location. These findings indicate that visual activity in the frontal eye field signals the location of targets for orienting, whereas movement-related activity instantiates saccade preparation.

Characterization of the sleep-wake patterns in mice lacking fatty acid amide hydrolase.

PubMed

Huitron-Resendiz, Salvador; Sanchez-Alavez, Manuel; Wills, Derek N; Cravatt, Benjamin F; Henriksen, Steven J

2004-08-01

Oleamide and anandamide are fatty acid amides implicated in the regulatory mechanisms of sleep processes. However, due to their prompt catabolism by fatty acid amide hydrolase (FAAH), their pharmacologic and behavioral effects, in vivo, disappear rapidly. To determine if, in the absence of FAAH, the hypnogenic fatty acid amides induce an increase of sleep, we characterized the sleep-wake patters in FAAH-knockout mice [FAAH (-/-)] before and after sleep deprivation. FAAH (-/-), FAAH (+/-), and FAAH (+/+) mice were implanted chronically for sleep, body temperature (Tb), and locomotor activity (LMA) recordings. Sleep-wake states were recorded during a 24-hour baseline session followed by 8 hours of sleep deprivation. Recovery recordings were done during the 16 hours following sleep deprivation. Total amount of wake, slow-wave sleep, and rapid eye movement sleep were calculated and compared between genotypes. The electroencephalographic spectral analysis was performed by fast Fourier transform analysis. Telemetry recordings of Tb and LMA were carried out continuously during 4 days under baseline conditions. N/A. FAAH (-/-) mice and their heterozygote (+/-) and control (+/+) littermates were used. Sleep deprivation. FAAH (-/-) mice possess higher values of slow-wave sleep and more intense episodes of slow-wave sleep than do control littermates under baseline conditions that are not related to differences in Tb and LMA. A rebound of slow-wave sleep and rapid eye movement sleep as well an increase in the levels of slow-wave activity were observed after sleep deprivation in all genotypes. These findings support the role of fatty acid amides as possible modulators of sleep and indicate that the homeostatic mechanisms of sleep in FAAH (-/-) mice are not disrupted.

Evaluation of the King-Devick Test to Assess Eye Movements and the Performance of Rapid Number Naming in Concussed and Non-Concussed Service Members

DTIC Science & Technology

2017-07-01

pre -Combatives baseline and their post - Combatives assessment, to determine to what extent individuals diagnosed as having an mTBI event differ from...their King- Devick Test pre -Combatives baseline, and to determine to what extent individuals who report a history of concussion during their pre ...Award Number: W81XWH-14-1-0173 TITLE: Evaluation of the King-Devick Test to Assess Eye Movements and the Performance of Rapid Number Naming in

Eye closure in darkness animates olfactory and gustatory cortical areas.

PubMed

Wiesmann, M; Kopietz, R; Albrecht, J; Linn, J; Reime, U; Kara, E; Pollatos, O; Sakar, V; Anzinger, A; Fesl, G; Brückmann, H; Kobal, G; Stephan, T

2006-08-01

In two previous fMRI studies, it was reported that eyes-open and eyes-closed conditions in darkness had differential effects on brain activity, and typical patterns of cortical activity were identified. Without external stimulation, ocular motor and attentional systems were activated when the eyes were open. On the contrary, the visual, somatosensory, vestibular, and auditory systems were activated when the eyes were closed. In this study, we investigated whether cortical areas related to the olfactory and gustatory system are also animated by eye closure without any other external stimulation. In a first fMRI experiment (n = 22), we identified cortical areas including the piriform cortex activated by olfactory stimulation. In a second experiment (n = 12) subjects lying in darkness in the MRI scanner alternately opened and closed their eyes. In accordance to previous studies, we found activation clusters bilaterally in visual, somatosensory, vestibular and auditory cortical areas for the contrast eyes-closed vs. eyes-open. In addition, we were able to show that cortical areas related to the olfactory and gustatory system were also animated by eye closure. These results support the hypothesis that there are two different states of mental activity: with the eyes closed, an "interoceptive" state characterized by imagination and multisensory activity and with the eyes open, an "exteroceptive" state characterized by attention and ocular motor activity. Our study also suggests that the chosen baseline condition may have a considerable impact on activation patterns and on the interpretation of brain activation studies. This needs to be considered for studies of the olfactory and gustatory system.

Sleep and youth suicidal behavior: a neglected field.

PubMed

Liu, Xianchen; Buysse, Daniel J

2006-05-01

Sleep undergoes substantial changes during adolescence and suicide risk begins to increase during this period as well. This review focuses on recent literature on the relationship between sleep and suicidal behavior and proposes directions for future research. Adolescent sleep is characterized by widespread sleep restriction, irregular sleep schedules, daytime sleepiness, and elevated risk for sleep disturbances. More research on adolescent sleep and psychosocial impairment, psychiatric disorders, and suicidal behavior has been conducted. Suicidal psychiatric patients had more sleep disturbances including insomnia, hypersomnia, or nightmares than nonsuicidal patients. Shorter rapid eye movement latency and increased rapid eye movement activity have been noted to be a marker of suicidality in psychiatric patients. Epidemiological studies have demonstrated that insomnia, nightmares, and sleep insufficiency are associated with elevated risk for suicide. Although the link between insomnia and suicidal behavior appears to be mediated by depression, existing data suggest an independent predictive role of nightmares in future suicidal behavior. Sleep loss or disturbances are likely to signal an increased risk of future suicidal action in adolescents. Large-scale prospective studies and neurobiological studies are needed for a better understanding of the complex relationship between sleep, psychopathology, and youth suicidal behavior.

Sickness behaviour after lipopolysaccharide treatment in ghrelin deficient mice.

PubMed

Szentirmai, Éva; Krueger, James M

2014-02-01

Ghrelin is an orexigenic hormone produced mainly by the gastrointestinal system and the brain. Much evidence also indicates a role for ghrelin in sleep and thermoregulation. Further, ghrelin was recently implicated in immune system modulation. Administration of bacterial lipopolysaccharide (LPS) induces fever, anorexia, and increased non-rapid-eye movement sleep (NREMS) and these actions are mediated primarily by proinflammatory cytokines. Ghrelin reduces LPS-induced fever, suppresses circulating levels of proinflammatory cytokines and reduces the severity and mortality of various models of experimental endotoxemia. In the present study, we determined the role of intact ghrelin signaling in LPS-induced sleep, feeding, and thermoregulatory responses in mice. Sleep-wake activity was determined after intraperitoneal, dark onset administration of 0.4, 2 and 10 μg LPS in preproghrelin knockout (KO) and wild-type (WT) mice. In addition, body temperature, motor activity and changes in 24-h food intake and body weight were measured. LPS induced dose-dependent increases in NREMS, and suppressed rapid-eye movement sleep, electroencephalographic slow-wave activity, motor activity, food intake and body weight in both Ppg KO and WT mice. Body temperature changes showed a biphasic pattern with a decrease during the dark period followed by an increase in the light phase. The effects of the low and middle doses of LPS were indistinguishable between the two genotypes. Administration of 10 μg LPS, however, induced significantly larger changes in NREMS and wakefulness amounts, body temperature, food intake and body weight in the Ppg KO mice. These findings support a role for ghrelin as an endogenous modulator of inflammatory responses and a central component of arousal and feeding circuits. Copyright © 2013 Elsevier Inc. All rights reserved.

Rapid eye movements during sleep in mice: High trait-like stability qualifies rapid eye movement density for characterization of phenotypic variation in sleep patterns of rodents

PubMed Central

2011-01-01

Background In humans, rapid eye movements (REM) density during REM sleep plays a prominent role in psychiatric diseases. Especially in depression, an increased REM density is a vulnerability marker for depression. In clinical practice and research measurement of REM density is highly standardized. In basic animal research, almost no tools are available to obtain and systematically evaluate eye movement data, although, this would create increased comparability between human and animal sleep studies. Methods We obtained standardized electroencephalographic (EEG), electromyographic (EMG) and electrooculographic (EOG) signals from freely behaving mice. EOG electrodes were bilaterally and chronically implanted with placement of the electrodes directly between the musculus rectus superior and musculus rectus lateralis. After recovery, EEG, EMG and EOG signals were obtained for four days. Subsequent to the implantation process, we developed and validated an Eye Movement scoring in Mice Algorithm (EMMA) to detect REM as singularities of the EOG signal, based on wavelet methodology. Results The distribution of wakefulness, non-REM (NREM) sleep and rapid eye movement (REM) sleep was typical of nocturnal rodents with small amounts of wakefulness and large amounts of NREM sleep during the light period and reversed proportions during the dark period. REM sleep was distributed correspondingly. REM density was significantly higher during REM sleep than NREM sleep. REM bursts were detected more often at the end of the dark period than the beginning of the light period. During REM sleep REM density showed an ultradian course, and during NREM sleep REM density peaked at the beginning of the dark period. Concerning individual eye movements, REM duration was longer and amplitude was lower during REM sleep than NREM sleep. The majority of single REM and REM bursts were associated with micro-arousals during NREM sleep, but not during REM sleep. Conclusions Sleep-stage specific distributions of REM in mice correspond to human REM density during sleep. REM density, now also assessable in animal models through our approach, is increased in humans after acute stress, during PTSD and in depression. This relationship can now be exploited to match animal models more closely to clinical situations, especially in animal models of depression. PMID:22047102

The Rat With Oxygen-Induced Retinopathy Is Myopic With Low Retinal Dopamine

PubMed Central

Zhang, Nan; Favazza, Tara L.; Baglieri, Anna Maria; Benador, Ilan Y.; Noonan, Emily R.; Fulton, Anne B.; Hansen, Ronald M.; Iuvone, P. Michael; Akula, James D.

2013-01-01

Purpose. Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. Methods. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). Results. The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. Conclusions. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia. PMID:24168993

The rat with oxygen-induced retinopathy is myopic with low retinal dopamine.

PubMed

Zhang, Nan; Favazza, Tara L; Baglieri, Anna Maria; Benador, Ilan Y; Noonan, Emily R; Fulton, Anne B; Hansen, Ronald M; Iuvone, P Michael; Akula, James D

2013-12-19

Dopamine (DA) is a neurotransmitter implicated both in modulating neural retinal signals and in eye growth. Therefore, it may participate in the pathogenesis of the most common clinical sequelae of retinopathy of prematurity (ROP), visual dysfunction and myopia. Paradoxically, in ROP myopia the eye is usually small. The eye of the rat with oxygen-induced retinopathy (OIR) is characterized by retinal dysfunction and short axial length. There have been several investigations of the early maturation of DA in rat retina, but little at older ages, and not in the OIR rat. Therefore, DA, retinal function, and refractive state were investigated in the OIR rat. In one set of rats, the development of dopaminergic (DAergic) networks was evaluated in retinal cross-sections from rats aged 14 to 120 days using antibodies against tyrosine hydroxylase (TH, the rate-limiting enzyme in the biosynthesis of DA). In another set of rats, retinoscopy was used to evaluate spherical equivalent (SE), electoretinography (ERG) was used to evaluate retinal function, and high-pressure liquid chromatography (HPLC) was used to evaluate retinal contents of DA, its precursor levodopamine (DOPA), and its primary metabolite 3,4-dihydroxyphenylacetic acid (DOPAC). The normally rapid postnatal ramification of DAergic neurons was disrupted in OIR rats. Retinoscopy revealed that OIR rats were relatively myopic. In the same eyes, ERG confirmed retinal dysfunction in OIR. HPLC of those eyes' retinae confirmed low DA. Regression analysis indicated that DA metabolism (evaluated by the ratio of DOPAC to DA) was an important additional predictor of myopia beyond OIR. The OIR rat is the first known animal model of myopia in which the eye is smaller than normal. Dopamine may modulate, or fail to modulate, neural activity in the OIR eye, and thus contribute to this peculiar myopia.

Rapid motor learning in the translational vestibulo-ocular reflex

NASA Technical Reports Server (NTRS)

Zhou, Wu; Weldon, Patrick; Tang, Bingfeng; King, W. M.; Shelhamer, M. J. (Principal Investigator)

2003-01-01

Motor learning was induced in the translational vestibulo-ocular reflex (TVOR) when monkeys were repeatedly subjected to a brief (0.5 sec) head translation while they tried to maintain binocular fixation on a visual target for juice rewards. If the target was world-fixed, the initial eye speed of the TVOR gradually increased; if the target was head-fixed, the initial eye speed of the TVOR gradually decreased. The rate of learning acquisition was very rapid, with a time constant of approximately 100 trials, which was equivalent to <1 min of accumulated stimulation. These learned changes were consolidated over >or=1 d without any reinforcement, indicating induction of long-term synaptic plasticity. Although the learning generalized to targets with different viewing distances and to head translations with different accelerations, it was highly specific for the particular combination of head motion and evoked eye movement associated with the training. For example, it was specific to the modality of the stimulus (translation vs rotation) and the direction of the evoked eye movement in the training. Furthermore, when one eye was aligned with the heading direction so that it remained motionless during training, learning was not expressed in this eye, but only in the other nonaligned eye. These specificities show that the learning sites are neither in the sensory nor the motor limb of the reflex but in the sensory-motor transformation stage of the reflex. The dependence of the learning on both head motion and evoked eye movement suggests that Hebbian learning may be one of the underlying cellular mechanisms.

M.I.T./Canadian vestibular experiments on the Spacelab-1 mission. V - Postural responses following exposure to weightlessness

NASA Technical Reports Server (NTRS)

Kenyon, R. V.; Young, L. R.

1986-01-01

The four science crewmembers of Spacelab-1 were tested for postural control before and after a 10 day mission in weightlessness. Previous reports have shown changes in astronaut postural behavior following a return to earth's 1-g field. This study was designed to identify changes in EMG latency and amplitudes that might explain the instabilities observed post-flight. Erect posture was tested having the subject stand on a pneumatically driven posture platform which pitched rapidly and unexpectedly about the ankles causing dorsi- and plantarflexion. Electromyographic (EMG) activity from the tibialis anterior and the gastrocnemius-soleus muscles was measured during eyes open and eyes closed trials. The early (pre 500 ms) EMG response characteristics (latency, amplitude) in response to a disturbance in the posture of the subject were apparently unchanged by the 10 days of weightlessness. However, the late (post 500 ms) response showed higher amplitudes than was found pre-flight. General postural control was quantitatively measured pre- and post-flight by a 'sharpened Romberg Rails test'. This test showed decrements in standing stability with eyes closed for several days post-flight.

Neural Regulation of Lacrimal Gland Secretory Processes: Relevance in Dry Eye Diseases

PubMed Central

Dartt, Darlene A.

2013-01-01

The lacrimal gland is the major contributor to the aqueous layer of the tear film which consists of water, electrolytes and proteins. The amount and composition of this layer is critical for the health, maintenance, and protection of the cells of the cornea and conjunctiva (the ocular surface). Small changes in the concentration of tear electrolytes have been correlated with dry eye syndrome. While the mechanisms of secretion of water, electrolytes and proteins from the lacrimal gland differ, all three are under tight neural control. This allows for a rapid response to meet the needs of the cells of the ocular surface in response to environmental conditions. The neural response consists of the activation of the afferent sensory nerves in the cornea and conjunctiva to stimulate efferent parasympathetic and sympathetic nerves that innervate the lacrimal gland. Neurotransmitters are released from the stimulated parasympathetic and sympathetic nerves that cause secretion of water, electrolytes, and proteins from the lacrimal gland and onto the ocular surface. This review focuses on the neural regulation of lacrimal gland secretion under normal and dry eye conditions. PMID:19376264

Mucoadhesive microparticles with a nanostructured surface for enhanced bioavailability of glaucoma drug.

PubMed

Park, Chun Gwon; Kim, Young Kook; Kim, Mi Jeung; Park, Min; Kim, Myung Hun; Lee, Seung Ho; Choi, Sung Yoon; Lee, Won Seok; Chung, You Jung; Jung, Young Eun; Park, Ki Ho; Choy, Young Bin

2015-12-28

Topical drug administration to the eye is limited by low drug bioavailability due to its rapid clearance from the preocular surface. Thus, multiple daily administrations are often needed, but patient compliance is low, hence a high chance of unsatisfactory treatment of ocular diseases. To resolve this, we propose mucoadhesive microparticles with a nanostructured surface as potential carriers for delivery of brimonidine, an ocular drug for glaucoma treatment. For sustained drug delivery, the microparticles were composed mainly of a diffusion-wall material, poly(lactic-co-glycolic acid) and a mucoadhesive polymer, polyethylene glycol, was used as an additive. Due to their nanostructured surface, the microparticles with a mucoadhesive material exhibited a 13-fold increase in specific surface area and could thus adhere better to the mucous layer on the eye, as compared with the conventional spherical microparticles. When loaded with brimonidine, the mucoadhesive microparticles with a nanostructured surface increased both drug bioavailability and its activity period by a factor of more than 2 over Alphagan P, a marketed eye drop of brimonidine. Copyright © 2015 Elsevier B.V. All rights reserved.

Real time eye tracking using Kalman extended spatio-temporal context learning

NASA Astrophysics Data System (ADS)

Munir, Farzeen; Minhas, Fayyaz ul Amir Asfar; Jalil, Abdul; Jeon, Moongu

2017-06-01

Real time eye tracking has numerous applications in human computer interaction such as a mouse cursor control in a computer system. It is useful for persons with muscular or motion impairments. However, tracking the movement of the eye is complicated by occlusion due to blinking, head movement, screen glare, rapid eye movements, etc. In this work, we present the algorithmic and construction details of a real time eye tracking system. Our proposed system is an extension of Spatio-Temporal context learning through Kalman Filtering. Spatio-Temporal Context Learning offers state of the art accuracy in general object tracking but its performance suffers due to object occlusion. Addition of the Kalman filter allows the proposed method to model the dynamics of the motion of the eye and provide robust eye tracking in cases of occlusion. We demonstrate the effectiveness of this tracking technique by controlling the computer cursor in real time by eye movements.

Local sleep homeostasis in the avian brain: convergence of sleep function in mammals and birds?

PubMed

Lesku, John A; Vyssotski, Alexei L; Martinez-Gonzalez, Dolores; Wilzeck, Christiane; Rattenborg, Niels C

2011-08-22

The function of the brain activity that defines slow wave sleep (SWS) and rapid eye movement (REM) sleep in mammals is unknown. During SWS, the level of electroencephalogram slow wave activity (SWA or 0.5-4.5 Hz power density) increases and decreases as a function of prior time spent awake and asleep, respectively. Such dynamics occur in response to waking brain use, as SWA increases locally in brain regions used more extensively during prior wakefulness. Thus, SWA is thought to reflect homeostatically regulated processes potentially tied to maintaining optimal brain functioning. Interestingly, birds also engage in SWS and REM sleep, a similarity that arose via convergent evolution, as sleeping reptiles and amphibians do not show similar brain activity. Although birds deprived of sleep show global increases in SWA during subsequent sleep, it is unclear whether avian sleep is likewise regulated locally. Here, we provide, to our knowledge, the first electrophysiological evidence for local sleep homeostasis in the avian brain. After staying awake watching David Attenborough's The Life of Birds with only one eye, SWA and the slope of slow waves (a purported marker of synaptic strength) increased only in the hyperpallium--a primary visual processing region--neurologically connected to the stimulated eye. Asymmetries were specific to the hyperpallium, as the non-visual mesopallium showed a symmetric increase in SWA and wave slope. Thus, hypotheses for the function of mammalian SWS that rely on local sleep homeostasis may apply also to birds.

Rapid eye movement sleep debt accrues in mice exposed to volatile anesthetics

PubMed Central

Pick, Jeremy; Chen, Yihan; Moore, Jason T.; Sun, Yi; Wyner, Abraham J.; Friedman, Eliot B.; Kelz, Max B.

2011-01-01

Background General anesthesia has been likened to a state in which anesthetized subjects are locked out of access to both rapid eye movement (REM) sleep and wakefulness. Were this true for all anesthetics, one might expect a significant REM rebound following anesthetic exposure. However, for the intravenous anesthetic propofol, studies demonstrate that no sleep debt accrues. Moreover, pre-existing sleep debts dissipate during propofol anesthesia. To determine whether these effects are specific to propofol or are typical of volatile anesthetics we tested the hypothesis that REM sleep debt would accrue in rodents anesthetized with volatile anesthetics. Methods Electroencephalographic and electromyographic electrodes were implanted in 10 mice. After 9–11 days of recovery and habituation to a 12h:12h light:dark cycle, baseline states of wakefulness, non-rapid eye movement sleep, and REM sleep were recorded in mice exposed to 6 hours of an oxygen control and on separate days to 6 hours of isoflurane, sevoflurane, or halothane in oxygen. All exposures were conducted at the onset of light. Results Mice in all three anesthetized groups exhibited a significant doubling of REM sleep during the first six-hours of the dark phase of the circadian schedule while only mice exposed to halothane displayed a significant increase in non-rapid eye movement sleep that peaked at 152% of baseline. Conclusion REM sleep rebound following exposure to volatile anesthetics suggests that these volatile anesthetics do not fully substitute for natural sleep. This result contrasts with the published actions of propofol for which no REM sleep rebound occurred. PMID:21934405

Characterization and delineation of caribou habitat on Unimak Island using remote sensing techniques

NASA Astrophysics Data System (ADS)

Atkinson, Brain M.

The assessment of herbivore habitat quality is traditionally based on quantifying the forages available to the animal across their home range through ground-based techniques. While these methods are highly accurate, they can be time-consuming and highly expensive, especially for herbivores that occupy vast spatial landscapes. The Unimak Island caribou herd has been decreasing in the last decade at rates that have prompted discussion of management intervention. Frequent inclement weather in this region of Alaska has provided for little opportunity to study the caribou forage habitat on Unimak Island. The overall objectives of this study were two-fold 1) to assess the feasibility of using high-resolution color and near-infrared aerial imagery to map the forage distribution of caribou habitat on Unimak Island and 2) to assess the use of a new high-resolution multispectral satellite imagery platform, RapidEye, and use of the "red-edge" spectral band on vegetation classification accuracy. Maximum likelihood classification algorithms were used to create land cover maps in aerial and satellite imagery. Accuracy assessments and transformed divergence values were produced to assess vegetative spectral information and classification accuracy. By using RapidEye and aerial digital imagery in a hierarchical supervised classification technique, we were able to produce a high resolution land cover map of Unimak Island. We obtained overall accuracy rates of 71.4 percent which are comparable to other land cover maps using RapidEye imagery. The "red-edge" spectral band included in the RapidEye imagery provides additional spectral information that allows for a more accurate overall classification, raising overall accuracy 5.2 percent.

The Role of Eye Movement Desensitization and Reprocessing (EMDR) Therapy in Medicine: Addressing the Psychological and Physical Symptoms Stemming from Adverse Life Experiences

PubMed Central

Shapiro, Francine

2014-01-01

Background: A substantial body of research shows that adverse life experiences contribute to both psychological and biomedical pathology. Eye movement desensitization and reprocessing (EMDR) therapy is an empirically validated treatment for trauma, including such negative life experiences as commonly present in medical practice. The positive therapeutic outcomes rapidly achieved without homework or detailed description of the disturbing event offer the medical community an efficient treatment approach with a wide range of applications. Methods: All randomized studies and significant clinical reports related to EMDR therapy for treating the experiential basis of both psychological and somatic disorders are reviewed. Also reviewed are the recent studies evaluating the eye movement component of the therapy, which has been posited to contribute to the rapid improvement attributable to EMDR treatment. Results: Twenty-four randomized controlled trials support the positive effects of EMDR therapy in the treatment of emotional trauma and other adverse life experiences relevant to clinical practice. Seven of 10 studies reported EMDR therapy to be more rapid and/or more effective than trauma-focused cognitive behavioral therapy. Twelve randomized studies of the eye movement component noted rapid decreases in negative emotions and/or vividness of disturbing images, with an additional 8 reporting a variety of other memory effects. Numerous other evaluations document that EMDR therapy provides relief from a variety of somatic complaints. Conclusion: EMDR therapy provides physicians and other clinicians with an efficient approach to address psychological and physiologic symptoms stemming from adverse life experiences. Clinicians should therefore evaluate patients for experiential contributors to clinical manifestations. PMID:24626074

Independent associations between fatty acids and sleep quality among obese patients with obstructive sleep apnoea syndrome.

PubMed

Papandreou, Christopher

2013-10-01

The aim of this study was to examine the relationships between gluteal adipose tissue fatty acids and sleep quality in obese patients with obstructive sleep apnoea syndrome after controlling for possible confounders. Sixty-three patients with obstructive sleep apnoea syndrome based on overnight attended polysomnography were included. Gluteal adipose tissue fatty acids were analysed by gas chromatography. Anthropometric measurements were carried out. Depressive symptoms were assessed by the Zung Self-rating Depression Scale. Saturated fatty acids were positively related to total sleep time, sleep efficiency and rapid eye movement sleep. Significant positive associations were found between polyunsaturated fatty acids and sleep efficiency and rapid eye movement sleep. Moreover, n-3 fatty acids were positively associated with sleep efficiency, slow wave sleep and rapid eye movement sleep. This study revealed independent associations between certain gluteal adipose tissue fatty acids and sleep quality after controlling for age, gender, obesity, obstructive sleep apnoea syndrome indices and Zung Self-rating Depression Scale scores in patients with moderate to severe obstructive sleep apnoea syndrome. © 2013 European Sleep Research Society.

Nonmotor symptoms in patients with Parkinson disease

PubMed Central

Zhang, Tie-mei; Yu, Shu-yang; Guo, Peng; Du, Yang; Hu, Yang; Piao, Ying-shan; Zuo, Li-jun; Lian, Teng-hong; Wang, Rui-dan; Yu, Qiu-jin; Jin, Zhao; Zhang, Wei

2016-01-01

Abstract Parkinson disease (PD) is usually accompanied by numerous nonmotor symptoms (NMS), such as neuropsychiatric symptoms, sleep disorders, autonomic dysfunctions, and sensory disturbances. However, it is not clear that the factors influencing the occurrence of NMS and its sequence with motor symptoms (MS). We conducted comprehensive assessments of NMS by using 13 scales in 1119 PD patients. A total of 70.8% PD patients present NMS. Olfactory dysfunction tends to occur in PD patients with older age, more severe depression, sleep problems, and autonomic dysfunctions. Older patients are more likely to have olfactory dysfunction before MS than younger patients. Rapid eye movement behavior disorder is more prone to happen in patients with older age, older onset age, more severe depression, sleep problems, and autonomic dysfunctions. Patients with rapid eye movement behavior disorder before MS are older in onset age than after group. Olfactory dysfunction, constipation, rapid eye movement behavior disorder, and depression, as early warning NMSs of PD, connected to each other. There is a clinical heterogeneity that older patients are more likely to have NMS before MS, while younger patients are opposite. PMID:27977578

Epidemiology of hereditary ocular disorders.

PubMed

Rosenberg, Thomas

2003-01-01

Molecular genetic evidence has contributed significantly to the understanding of the fundamental molecular biology of the eye in health and disease, but it has also exposed the inadequacy of our traditional clinically based classification of hereditary eye disorders by unravelling significant genetic non-allelic heterogeneity in many eye disorders. Furthermore, our understanding of the epidemiology of hereditary ocular disorders has gained considerably by the establishment of mutation spectra in a rapidly growing number of monogenic eye disorders. In this overview, special emphasis has been put on the growing impact of genetic eye diseases in visual impairment, genetic heterogeneity, and the role of founder mutations for the skewed appearance of certain hereditary ocular disorders in some populations.

Successful Surgical Management of Retinopathy of Prematurity Showing Rapid Progression despite Extensive Retinal Photocoagulation.

PubMed

Gadkari, Salil S; Kulkarni, Sucheta R; Kamdar, Rushita R; Deshpande, Madan

2015-01-01

The management of retinopathy of prematurity (ROP) can be challenging in preterm babies with a gestational age <30 weeks, those with very low birth weight and multiple risk factors (eg., oxygen therapy for respiratory distress, sepsis, neonatal jaundice). A premature infant presented with "hybrid" zone 1 disease in the right eye and aggressive posterior ROP in the left eye. Both eyes were adequately treated with laser photocoagulation; however, the eyes deteriorated and progressed to stage 4 ROP. Both eyes eventually underwent intravitreal bevacizumab followed by lens sparing vitrectomy with good anatomical and visual outcome. Anticipation of progression despite laser photocoagulation in certain clinical scenarios, frequent follow-up and timely surgical intervention is paramount.

Sample entropy tracks changes in electroencephalogram power spectrum with sleep state and aging.

PubMed

Bruce, Eugene N; Bruce, Margaret C; Vennelaganti, Swetha

2009-08-01

The regularity of electroencephalogram signals was compared between middle-aged (47.2 +/- 2.0 years) and elderly (78.4 +/- 3.8 years) female subjects in wake, nonrapid eye movement stages 2 and 3 (S-2, S-3), and rapid eye movement sleep. Signals from C3A2 leads of healthy subjects, acquired from polysomnograms obtained from the Sleep Heart Health Study, were analyzed using both sample entropy (SaEn) and power spectral analysis (delta, theta, alpha, and beta frequency band powers). SaEn changed systematically and significantly (P < 0.001) with sleep state in both age groups, following the relationships wake > rapid eye movement > S-2 > S-3. SaEn was found to be negatively correlated with delta power and positively correlated with beta power. Small changes in SaEn seem to reflect changes in spectral content rather than changes in regularity of the signal. A better predictor of SaEn than the frequency band powers was the logarithm of the power ratio (alpha + beta)/(delta + theta). Thus, SaEn seems to reflect the balance between sleep-promoting and alertness-promoting mechanisms. SaEn of the elderly was larger than that of middle-aged subjects in S-2 (P = 0.029) and rapid eye movement (P = 0.001), suggesting that cortical state is shifted toward alertness in elderly subjects in these sleep states compared with the middle-aged subjects.

Cat and mouse search: the influence of scene and object analysis on eye movements when targets change locations during search.

PubMed

Hillstrom, Anne P; Segabinazi, Joice D; Godwin, Hayward J; Liversedge, Simon P; Benson, Valerie

2017-02-19

We explored the influence of early scene analysis and visible object characteristics on eye movements when searching for objects in photographs of scenes. On each trial, participants were shown sequentially either a scene preview or a uniform grey screen (250 ms), a visual mask, the name of the target and the scene, now including the target at a likely location. During the participant's first saccade during search, the target location was changed to: (i) a different likely location, (ii) an unlikely but possible location or (iii) a very implausible location. The results showed that the first saccade landed more often on the likely location in which the target re-appeared than on unlikely or implausible locations, and overall the first saccade landed nearer the first target location with a preview than without. Hence, rapid scene analysis influenced initial eye movement planning, but availability of the target rapidly modified that plan. After the target moved, it was found more quickly when it appeared in a likely location than when it appeared in an unlikely or implausible location. The findings show that both scene gist and object properties are extracted rapidly, and are used in conjunction to guide saccadic eye movements during visual search.This article is part of the themed issue 'Auditory and visual scene analysis'. © 2017 The Author(s).

The neurobiology, diagnosis, and treatment of narcolepsy.

PubMed

Scammell, Thomas E

2003-02-01

Narcolepsy is a common cause of chronic sleepiness distinguished by intrusions into wakefulness of physiological aspects of rapid eye movement sleep such as cataplexy and hallucinations. Recent advances provide compelling evidence that narcolepsy may be a neurodegenerative or autoimmune disorder resulting in a loss of hypothalamic neurons containing the neuropeptide orexin (also known as hypocretin). Because orexin promotes wakefulness and inhibits rapid eye movement sleep, its absence may permit inappropriate transitions between wakefulness and sleep. These discoveries have considerably improved our understanding of the neurobiology of sleep and should foster the development of rational treatments for a variety of sleep disorders.

[Immunoassay for matrix metalloproteinase-9 in the tear film of patients with pseudoexfoliation syndrome - a pilot study].

PubMed

Zimmermann, N; Erb, C

2013-08-01

Matrix-metalloproteinases (MMPs) are proteolytic enzymes released by irritated epithelial cells of the ocular surface. It has been established that the subtype MMP-9 can serve as an inflammatory marker within the tear film. MMP-9 is also attributed to have an effect on the PEX-glaucoma development. Recently, a rapid immunoassay for detection of MMP-9 in the tear film was developed to estimate inflammatory extent during dry eye disease. The aim of this study was to analyse the MMP-9 concentration in tear film in PEX-syndrome. In addition, an assessment of the feasibility, reliability and readability of the test was done. We randomly selected 10 patients with PEX-syndrome and 10 healthy control patients and measured tear film MMP-9 of one eye with the RPS InflammaDry Detector™ (Rapid Pathogen Screening Inc., USA). We detected increased levels of MMP-9 in tear film in PEX-syndrome. 80 % of the PEX-patients and 20 % of the controls showed a positive test result (>or= 40 ng/mL MMP-9) indicating a test specificity and sensitivity of 80 %. This corresponds approximately to the published values for the dry eye (sensitivity 87 %, specificity: 92 %). The performance of the test is simple. The patients tolerated the inclusion of the test strips well. However, it is difficult to estimate whether enough tear film was used and in many cases, the intensity of the "indicator line" was weak. The rapid MMP-9-immunoassay is a novel, meaningful approach for the detection of inflammatory activity of the ocular surface. We have shown an up-regulation of the non-specific inflammatory marker MMP-9 in tear film in PEX-syndrome and suggest an association with a tear film disorder. However, an improvement in the estimation of the amount of collected tears and readability is desirable. Georg Thieme Verlag KG Stuttgart · New York.

Virtual reality and consciousness inference in dreaming

PubMed Central

Hobson, J. Allan; Hong, Charles C.-H.; Friston, Karl J.

2014-01-01

This article explores the notion that the brain is genetically endowed with an innate virtual reality generator that – through experience-dependent plasticity – becomes a generative or predictive model of the world. This model, which is most clearly revealed in rapid eye movement (REM) sleep dreaming, may provide the theater for conscious experience. Functional neuroimaging evidence for brain activations that are time-locked to rapid eye movements (REMs) endorses the view that waking consciousness emerges from REM sleep – and dreaming lays the foundations for waking perception. In this view, the brain is equipped with a virtual model of the world that generates predictions of its sensations. This model is continually updated and entrained by sensory prediction errors in wakefulness to ensure veridical perception, but not in dreaming. In contrast, dreaming plays an essential role in maintaining and enhancing the capacity to model the world by minimizing model complexity and thereby maximizing both statistical and thermodynamic efficiency. This perspective suggests that consciousness corresponds to the embodied process of inference, realized through the generation of virtual realities (in both sleep and wakefulness). In short, our premise or hypothesis is that the waking brain engages with the world to predict the causes of sensations, while in sleep the brain’s generative model is actively refined so that it generates more efficient predictions during waking. We review the evidence in support of this hypothesis – evidence that grounds consciousness in biophysical computations whose neuronal and neurochemical infrastructure has been disclosed by sleep research. PMID:25346710

Virtual reality and consciousness inference in dreaming.

PubMed

Hobson, J Allan; Hong, Charles C-H; Friston, Karl J

2014-01-01

This article explores the notion that the brain is genetically endowed with an innate virtual reality generator that - through experience-dependent plasticity - becomes a generative or predictive model of the world. This model, which is most clearly revealed in rapid eye movement (REM) sleep dreaming, may provide the theater for conscious experience. Functional neuroimaging evidence for brain activations that are time-locked to rapid eye movements (REMs) endorses the view that waking consciousness emerges from REM sleep - and dreaming lays the foundations for waking perception. In this view, the brain is equipped with a virtual model of the world that generates predictions of its sensations. This model is continually updated and entrained by sensory prediction errors in wakefulness to ensure veridical perception, but not in dreaming. In contrast, dreaming plays an essential role in maintaining and enhancing the capacity to model the world by minimizing model complexity and thereby maximizing both statistical and thermodynamic efficiency. This perspective suggests that consciousness corresponds to the embodied process of inference, realized through the generation of virtual realities (in both sleep and wakefulness). In short, our premise or hypothesis is that the waking brain engages with the world to predict the causes of sensations, while in sleep the brain's generative model is actively refined so that it generates more efficient predictions during waking. We review the evidence in support of this hypothesis - evidence that grounds consciousness in biophysical computations whose neuronal and neurochemical infrastructure has been disclosed by sleep research.

Spectral-analysis-based extraction of land disturbances arising from oil and gas development in diverse landscapes

NASA Astrophysics Data System (ADS)

Zhang, Ying; Lantz, Nicholas; Guindon, Bert; Jiao, Xianfen

2017-01-01

Accurate and frequent monitoring of land surface changes arising from oil and gas exploration and extraction is a key requirement for the responsible and sustainable development of these resources. Petroleum deposits typically extend over large geographic regions but much of the infrastructure required for oil and gas recovery takes the form of numerous small-scale features (e.g., well sites, access roads, etc.) scattered over the landscape. Increasing exploitation of oil and gas deposits will increase the presence of these disturbances in heavily populated regions. An object-based approach is proposed to utilize RapidEye satellite imagery to delineate well sites and related access roads in diverse complex landscapes, where land surface changes also arise from other human activities, such as forest logging and agriculture. A simplified object-based change vector approach, adaptable to operational use, is introduced to identify the disturbances on land based on red-green spectral response and spatial attributes of candidate object size and proximity to roads. Testing of the techniques has been undertaken with RapidEye multitemporal imagery in two test sites located at Alberta, Canada: one was a predominant natural forest landscape and the other landscape dominated by intensive agricultural activities. Accuracies of 84% and 73%, respectively, have been achieved for the identification of well site and access road infrastructure of the two sites based on fully automated processing. Limited manual relabeling of selected image segments can improve these accuracies to 95%.

Effects of oral temazepam on slow waves during non-rapid eye movement sleep in healthy young adults: A high-density EEG investigation.

PubMed

Plante, D T; Goldstein, M R; Cook, J D; Smith, R; Riedner, B A; Rumble, M E; Jelenchick, L; Roth, A; Tononi, G; Benca, R M; Peterson, M J

2016-03-01

Slow waves are characteristic waveforms that occur during non-rapid eye movement (NREM) sleep that play an integral role in sleep quality and brain plasticity. Benzodiazepines are commonly used medications that alter slow waves, however, their effects may depend on the time of night and measure used to characterize slow waves. Prior investigations have utilized minimal scalp derivations to evaluate the effects of benzodiazepines on slow waves, and thus the topography of changes to slow waves induced by benzodiazepines has yet to be fully elucidated. This study used high-density electroencephalography (hdEEG) to evaluate the effects of oral temazepam on slow wave activity, incidence, and morphology during NREM sleep in 18 healthy adults relative to placebo. Temazepam was associated with significant decreases in slow wave activity and incidence, which were most prominent in the latter portions of the sleep period. However, temazepam was also associated with a decrease in the magnitude of high-amplitude slow waves and their slopes in the first NREM sleep episode, which was most prominent in frontal derivations. These findings suggest that benzodiazepines produce changes in slow waves throughout the night that vary depending on cortical topography and measures used to characterize slow waves. Further research that explores the relationships between benzodiazepine-induced changes to slow waves and the functional effects of these waveforms is indicated. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid Eye Movements (REMs) and visual dream recall in both congenitally blind and sighted subjects

NASA Astrophysics Data System (ADS)

Bértolo, Helder; Mestre, Tiago; Barrio, Ana; Antona, Beatriz

2017-08-01

Our objective was to evaluate rapid eye movements (REMs) associated with visual dream recall in sighted subjects and congenital blind. During two consecutive nights polysomnographic recordings were performed at subjects home. REMs were detected by visual inspection on both EOG channels (EOG-H, EOG-V) and further classified as occurring isolated or in bursts. Dream recall was defined by the existence of a dream report. The two groups were compared using t-test and also the two-way ANOVA and a post-hoc Fisher test (for the features diagnosis (blind vs. sighted) and dream recall (yes or no) as a function of time). The average of REM awakenings per subject and the recall ability were identical in both groups. CB had a lower REM density than CS; the same applied to REM bursts and isolated eye movements. In the two-way ANOVA, REM bursts and REM density were significantly different for positive dream recall, mainly for the CB group and for diagnosis; furthermore for both features significant results were obtained for the interaction of time, recall and diagnosis; the interaction of recall and time was however, stronger. In line with previous findings the data show that blind have lower REMs density. However the ability of dream recall in congenitally blind and sighted controls is identical. In both groups visual dream recall is associated with an increase in REM bursts and density. REM bursts also show differences in the temporal profile. REM visual dream recall is associated with increased REMs activity.

Molecular identification of Neofabraea species associated with bull's-eye rot on apple using rolling-circle amplification of partial EF-1α sequence.

PubMed

Lin, Huijiao; Jiang, Xiang; Yi, Jianping; Wang, Xinguo; Zuo, Ranling; Jiang, Zide; Wang, Weifang; Zhou, Erxun

2018-01-01

A rolling-circle amplification (RCA) method with padlock probes targeted on EF-1α regions was developed for rapid detection of apple bull's-eye rot pathogens, including Neofabraea malicorticis, N. perennans, N. kienholzii, and N. vagabunda (synonym: N. alba). Four padlock probes (PLP-Nm, PLP-Np, PLP-Nk, and PLP-Nv) were designed and tested against 28 samples, including 22 BER pathogen cultures, 4 closely related species, and 2 unrelated species that may cause serious apple decays. The assay successfully identified all the bull's-eye rot pathogenic fungi at the level of species, while no cross-reaction was observed in all target species and no false-positive reaction was observed with all strains used for reference. This study showed that the use of padlock probes and the combination of probe signal amplification by RCA provided an effective and sensitive method for the rapid identification of Neofabraea spp. The method could therefore be a useful tool for monitoring bull's-eye rot pathogens in port quarantine and orchard epidemiological studies.

Incremental comprehension of pitch relationships in written music: Evidence from eye movements.

PubMed

Hadley, Lauren V; Sturt, Patrick; Eerola, Tuomas; Pickering, Martin J

2017-03-17

To investigate how proficient pianists comprehend pitch relationships in written music when they first encounter it we conducted two experiments in which proficient pianists' eyes were tracked while they read and played single-line melodies. In Experiment 1, participants played at their own speed; in Experiment 2 they played with an external metronome. The melodies were either congruent or anomalous, with the anomaly involving one bar being shifted in pitch to alter the implied harmonic structure (e.g., non-resolution of a dominant). In both experiments, anomaly led to rapid disruption in participants' eye-movements in terms of regressions from the target bar, indicating that pianists process written pitch relationships online. This is particularly striking because in musical sight-reading eye movement behaviour is constrained by the concurrent performance. Both experiments also showed that anomaly induced pupil dilation. Together these results indicate that proficient pianists rapidly integrate the music that they read into the prior context, and that anomalies in terms of pitch relationships lead to processing difficulty. These findings parallel those of text reading, suggesting that structural processing involves similar constraints across domains.

Different cellular effects of four anti-inflammatory eye drops on human corneal epithelial cells: independent in active components.

PubMed

Qu, Mingli; Wang, Yao; Yang, Lingling; Zhou, Qingjun

2011-01-01

To evaluate and compare the cellular effects of four commercially available anti-inflammatory eye drops and their active components on human corneal epithelial cells (HCECs) in vitro. The cellular effects of four eye drops (Bromfenac Sodium Hydrate Eye Drops, Pranoprofen Eye Drops, Diclofenac Sodium Eye Drops, and Tobramycin & Dex Eye Drops) and their corresponding active components were evaluated in an HCEC line with five in vitro assays. Cell proliferation and migration were measured using 3-(4,5)-dimethylthiahiazo (-z-y1)-3 5-di-phenytetrazoliumromide (MTT) assay and transwell migration assay. Cell damage was determined with the lactate dehydrogenase (LDH) assay. Cell viability and median lethal time (LT₅₀) were measured by 7-amino-actinomycin D (7-AAD) staining and flow cytometry analysis. Cellular effects after exposure of HCECs to the four anti-inflammatory eye drops were concentration dependent. The differences of cellular toxicity on cell proliferation became significant at lower concentrations (<0.002%). Diclofenac Sodium Eye Drops showed significant increasing effects on cell damage and viability when compared with the other three solutions. Tobramycin & Dex Eye Drops inhibited the migration of HCECs significantly. Tobramycin & Dex Eye Drops showed the quickest effect on cell viability: the LT₅₀ was 3.28, 9.23, 10.38, and 23.80 min for Tobramycin & Dex Eye Drops, Diclofenac Sodium Eye Drops, Pranoprofen Eye Drops, and Bromfenac Sodium Hydrate Eye Drops, respectively. However, the comparisons of cellular toxicity revealed significant differences between the eye drops and their active components under the same concentration. The corneal epithelial toxicity differences among the active components of the four eye drops became significant as higher concentration (>0.020%). The four anti-inflammatory eye drops showed different cellular effects on HCECs, and the toxicity was not related with their active components, which provides new reference for the clinical application and drug research and development.

Development of Methods for the Real-Time and Rapid Identification and Detection of TSE in Living Animals Using Fluorescence Spectroscopy of the Eye

DTIC Science & Technology

2006-07-01

retina . Our experiments have so far been limited to sheep. Our experiments have been designed to address the following questions: 1. Can ocular...We dissected sheep and cow eyes and performed fluorescence spectroscopy on all the major eye components and reports that the cornea, lens, retina ...excitation wavelengths λex = 410, 470, and 520 nm: retina ; optic nerve; outer tissue (sclera); and lens. • Contrary to the conclusions we

A Classification method for eye movements direction during REM sleep trained on wake electro-oculographic recordings.

PubMed

Betta, M; Laurino, M; Gemignani, A; Landi, A; Menicucci, D

2015-01-01

Rapid eye movements (REMs) are a peculiar and intriguing aspect of REM sleep, even if their physiological function still remains unclear. During this work, a new automatic tool was developed, aimed at a complete description of REMs activity during the night, both in terms of their timing of occurrence that in term of their directional properties. A classification stage of each singular movement detected during the night according to its main direction, was in fact added to our procedure of REMs detection and ocular artifact removal. A supervised classifier was constructed, using as training and validation set EOG data recorded during voluntary saccades of five healthy volunteers. Different classification methods were tested and compared. The further information about REMs directional characteristic provided by the procedure would represent a valuable tool for a deeper investigation into REMs physiological origin and functional meaning.

Declarative memory performance is associated with the number of sleep spindles in elderly women.

PubMed

Seeck-Hirschner, Mareen; Baier, Paul Christian; Weinhold, Sara Lena; Dittmar, Manuela; Heiermann, Steffanie; Aldenhoff, Josef B; Göder, Robert

2012-09-01

Recent evidence suggests that the sleep-dependent consolidation of declarative memory relies on the nonrapid eye movement rather than the rapid eye movement phase of sleep. In addition, it is known that aging is accompanied by changes in sleep and memory processes. Hence, the purpose of this study was to investigate the overnight consolidation of declarative memory in healthy elderly women. Sleep laboratory of University. Nineteen healthy elderly women (age range: 61-74 years). We used laboratory-based measures of sleep. To test declarative memory, the Rey-Osterrieth Complex Figure Test was performed. Declarative memory performance in elderly women was associated with Stage 2 sleep spindle density. Women characterized by high memory performance exhibited significantly higher numbers of sleep spindles and higher spindle density compared with women with generally low memory performance. The data strongly support theories suggesting a link between sleep spindle activity and declarative memory consolidation.

Rapid mapping of compound eye visual sampling parameters with FACETS, a highly automated wide-field goniometer.

PubMed

Douglass, John K; Wehling, Martin F

2016-12-01

A highly automated goniometer instrument (called FACETS) has been developed to facilitate rapid mapping of compound eye parameters for investigating regional visual field specializations. The instrument demonstrates the feasibility of analyzing the complete field of view of an insect eye in a fraction of the time required if using non-motorized, non-computerized methods. Faster eye mapping makes it practical for the first time to employ sample sizes appropriate for testing hypotheses about the visual significance of interspecific differences in regional specializations. Example maps of facet sizes are presented from four dipteran insects representing the Asilidae, Calliphoridae, and Stratiomyidae. These maps provide the first quantitative documentation of the frontal enlarged-facet zones (EFZs) that typify asilid eyes, which, together with the EFZs in male Calliphoridae, are likely to be correlated with high-spatial-resolution acute zones. The presence of EFZs contrasts sharply with the almost homogeneous distribution of facet sizes in the stratiomyid. Moreover, the shapes of EFZs differ among species, suggesting functional specializations that may reflect differences in visual ecology. Surveys of this nature can help identify species that should be targeted for additional studies, which will elucidate fundamental principles and constraints that govern visual field specializations and their evolution.

Processing Sentinel-2 data with ATCOR

NASA Astrophysics Data System (ADS)

Pflug, Bringfried; Makarau, Aliaksei; Richter, Rudolf

2016-04-01

Atmospheric correction of satellite images is necessary for many applications of remote sensing. Among them are applications for agriculture, forestry, land cover and land cover change, urban mapping, emergency and inland water. ATCOR is a widely used atmospheric correction tool which can process data of many optical satellite sensors, for instance Landsat, Sentinel-2, SPOT and RapidEye. ATCOR includes a terrain and adjacency correction of satellite images and several special algorithms like haze detection, haze correction, cirrus correction, de-shadowing and empirical methods for BRDF correction. The atmospheric correction tool ATCOR starts with an estimation of the vertical column Aerosol Optical Thickness (AOT550) at 550 nm. The mean uncertainty of the ATCOR-AOT550-estimation was estimated using Landsat and RapidEye data by direct comparison with sunphotometer data as a reference. For Landsat and RapidEye the uncertainty is ΔAOT550nm ≈ 0.03±0.02 for cloudless conditions with a cloud+haze fraction below 1%. Inclusion of cloudy and hazy satellite images into the analysis results in mean ΔAOT550nm ≈ 0.04±0.03 for both RapidEye and Landsat imagery. About 1/3 of the samples perform with the AOT uncertainty better than 0.02 and about 2/3 perform with AOT uncertainty better than 0.05. An accuracy of the retrieved surface reflectance of ±2% (for reflectance <10%) and ±4% reflectance units (for reflectance > 40%) can be achieved for flat terrain, and avoiding the specular and backscattering regions. ATCOR also supports the processing of Sentinel-2 data. First results of processing S2 data and a comparison with AERONET AOT values will be presented.

Sleep Architecture Linked to Airway Obstruction and Intracranial Hypertension in Children with Syndromic Craniosynostosis.

PubMed

Spruijt, Bart; Mathijssen, Irene M J; Bredero-Boelhouwer, Hansje H; Cherian, Perumpillichira J; Corel, Linda J A; van Veelen, Marie-Lise; Hayward, Richard D; Tasker, Robert C; Joosten, Koen F M

2016-12-01

Children with syndromic craniosynostosis often have obstructive sleep apnea and intracranial hypertension. The authors aimed to evaluate (1) sleep architecture, and determine whether this is influenced by the presence of obstructive sleep apnea and/or intracranial hypertension; and (2) the effect of treatment on sleep architecture. This study included patients with syndromic craniosynostosis treated at a national referral center, undergoing screening for obstructive sleep apnea and intracranial hypertension. Obstructive sleep apnea was identified by polysomnography, and categorized into no, mild, moderate, or severe. Intracranial hypertension was identified by the presence of papilledema on funduscopy, supplemented by optical coherence tomography and/or intracranial pressure monitoring. Regarding sleep architecture, sleep was divided into rapid eye movement or non-rapid eye movement sleep; respiratory effort-related arousals and sleep efficiency were scored. The authors included 39 patients (median age, 5.9 years): 19 with neither obstructive sleep apnea nor intracranial hypertension, 11 with obstructive sleep apnea (four moderate/severe), six with intracranial hypertension, and three with obstructive sleep apnea and intracranial hypertension. Patients with syndromic craniosynostosis, independent of the presence of mild obstructive sleep apnea and/or intracranial hypertension, have normal sleep architecture compared with age-matched controls. Patients with moderate/severe obstructive sleep apnea have a higher respiratory effort-related arousal index (p < 0.01), lower sleep efficiency (p = 0.01), and less rapid eye movement sleep (p = 0.04). An improvement in sleep architecture was observed following monobloc surgery (n = 5; rapid eye movement sleep, 5.3 percent; p = 0.04). Children with syndromic craniosynostosis have in principle normal sleep architecture. However, moderate/severe obstructive sleep apnea does lead to disturbed sleep architecture, which fits within a framework of a unifying theory for obstructive sleep apnea, intracranial hypertension, and sleep. Risk, II.

Relationships between Rapid Eye Movement Sleep Behavior Disorder and Neurodegenerative Diseases: Clinical Assessments, Biomarkers, and Treatment

PubMed Central

Li, Min; Wang, Li; Liu, Jiang-Hong; Zhan, Shu-Qin

2018-01-01

Objective: Rapid eye movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during rapid eye movement sleep. RBD is closely related to α-synucleinopathies including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Many studies have investigated the markers of imaging and neurophysiological, genetic, cognitive, autonomic function of RBD and their predictive value for neurodegenerative diseases. This report reviewed the progress of these studies and discussed their limitations and future research directions. Data Sources: Using the combined keywords: “RBD”, “neurodegenerative disease”, “Parkinson disease”, and “magnetic resonance imaging”, the PubMed/MEDLINE literature search was conducted up to January 1, 2018. Study Selection: A total of 150 published articles were initially identified citations. Of the 150 articles, 92 articles were selected after further detailed review. This study referred to all the important English literature in full. Results: Single-nucleotide polymorphisms in SCARB2 (rs6812193) and MAPT (rs12185268) were significantly associated with RBD. The olfactory loss, autonomic dysfunction, marked electroencephalogram slowing during both wakefulness and rapid eye movement sleep, and cognitive impairments were potential predictive markers for RBD conversion to neurodegenerative diseases. Traditional structural imaging studies reported relatively inconsistent results, whereas reduced functional connectivity between the left putamen and substantia nigra and dopamine transporter uptake demonstrated by functional imaging techniques were relatively consistent findings. Conclusions: More longitudinal studies should be conducted to evaluate the predictive value of biomarkers of RBD. Moreover, because the glucose and dopamine metabolisms are not specific for assessing cognitive cognition, the molecular metabolism directly related to cognition should be investigated. There is a need for more treatment trials to determine the effectiveness of interventions of RBD on preventing the conversion to neurodegenerative diseases. PMID:29664058

Options for using Landsat and RapidEye satellite images aiming the water productivity assessments in mixed agro-ecosystems

NASA Astrophysics Data System (ADS)

de C. Teixeira, Antônio H.; Leivas, Janice F.; Bayma-Silva, Gustavo

2016-10-01

For water productivity (WP) assessments, the SAFER (Surface Algorithm for Evapotranspiration Retrieving) algorithm for evapotranspiration (ET) and the Monteith's light use efficiency (LUE) model for biomass production (BIO), were applied to Landsat and RapidEye satellite images, in the Brazilian semiarid region, inside the dry season of 2011, in a mixture of irrigated and rainfed agro-ecosystems. Firstly, with the Landsat image, the methodology from which the surface temperature (T0) is derived as a residue in the radiation balance was tested. Low differences were detected, being Landsat ET with the thermal band averaged 0.9 +/- 1.5 mm d-1, while without it the mean value was 0.8 +/- 1.5 mm d-1. The corresponding Landsat BIO values were respectively 28 +/- 59 and 28 +/- 58 kg ha-1 d-1, resulting in mean WP of 1.3 +/- 1.3 kg m-3, in both cases. After having confidence on the residual methodology for retrieving T0 it was applied to the RapidEye image, resulting in average pixel values for ET, BIO and WP of 0.6 +/- 1.5 mm d-1, 26 +/- 58 kg ha-1 d-1 and 0.9 +/- 1.3 kg m-3, representing 75%, 93% and 69% of the Landsat ones obtained without the thermal band. In addition, the Surface Resistance Algorithm (SUREAL) was used to classify the agro-ecosystems into irrigated crops and natural vegetation by using the RapidEye image. The incremental values for ET, BIO and WP in 2011 were 2.0 +/- 1.3 mm d-1, 88 +/- 87 kg ha d-1 and 2.5 +/- 0.6 kg m-3, respectively, as a result of the replacement of the natural species by crops.

Healing of cornea following an electric burn.

PubMed

Chaudhry, Tanveer Anjum; Shaikh, Farheen; Ahmad, Khabir

2012-08-01

Electrical injuries have become a significant health problem in developing countries because of increase in access to electricity in the last few decades and lack of adequate safety measures. Electrical injuries of eyes are relatively uncommon. A case report of a rapid and complete corneal healing accompanied by satisfactory visual recovery after an electric burn event in a 20-year-old male is reported. The patient had accidental exposure to high voltage live wire while he was repairing it, resulting in severe ocular and superficial body burn. He was not wearing any protective equipment at the time of injury. On examination, the best-corrected visual acuity was counting fingers in the left eye with severe corneal epithelial loss and diffuse corneal oedema. The patient was treated medically, with a rapid corneal healing and resolution of oedema over the next few days. Visual acuity in the worse eye (left) improved to 20/25 from counting fingers.

An Analysis of the Time Course of Lexical Processing During Reading

PubMed Central

Sheridan, Heather; Reichle, Erik D.

2016-01-01

Reingold, Reichle, Glaholt, and Sheridan (2012) reported a gaze-contingent eye-movement experiment in which survival-curve analyses were used to examine the effects of word frequency, the availability of parafoveal preview, and initial fixation location on the time course of lexical processing. The key results of these analyses suggest that lexical processing begins very rapidly (after approximately 120 ms), and is supported by substantial parafoveal processing (more than 100 ms). Because it is not immediately obvious that these results are congruent with the theoretical assumption that words are processed and identified in a strictly serial manner, we attempted to simulate the experiment using the E-Z Reader model of eye-movement control (Reichle, 2011). These simulations were largely consistent with the empirical results, suggesting that parafoveal processing does play an important functional role by allowing lexical processing to occur rapidly enough to mediate direct control over when the eyes move during reading. PMID:25939443

Integrating the Advanced Human Eye Model (AHEM) and optical instrument models to model complete visual optical systems inclusive of the typical or atypical eye

NASA Astrophysics Data System (ADS)

Donnelly, William J., III

2012-06-01

PURPOSE: To present a commercially available optical modeling software tool to assist the development of optical instrumentation and systems that utilize and/or integrate with the human eye. METHODS: A commercially available flexible eye modeling system is presented, the Advanced Human Eye Model (AHEM). AHEM is a module that the engineer can use to perform rapid development and test scenarios on systems that integrate with the eye. Methods include merging modeled systems initially developed outside of AHEM and performing a series of wizard-type operations that relieve the user from requiring an optometric or ophthalmic background to produce a complete eye inclusive system. Scenarios consist of retinal imaging of targets and sources through integrated systems. Uses include, but are not limited to, optimization, telescopes, microscopes, spectacles, contact and intraocular lenses, ocular aberrations, cataract simulation and scattering, and twin eye model (binocular) systems. RESULTS: Metrics, graphical data, and exportable CAD geometry are generated from the various modeling scenarios.

Cerebral correlates of delta waves during non-REM sleep revisited.

PubMed

Dang-Vu, Thien Thanh; Desseilles, Martin; Laureys, Steven; Degueldre, Christian; Perrin, Fabien; Phillips, Christophe; Maquet, Pierre; Peigneux, Philippe

2005-10-15

We aimed at characterizing the neural correlates of delta activity during Non Rapid Eye Movement (NREM) sleep in non-sleep-deprived normal young adults, based on the statistical analysis of a positron emission tomography (PET) sleep data set. One hundred fifteen PET scans were obtained using H(2)(15)O under continuous polygraphic monitoring during stages 2-4 of NREM sleep. Correlations between regional cerebral blood flow (rCBF) and delta power (1.5-4 Hz) spectral density were analyzed using statistical parametric mapping (SPM2). Delta power values obtained at central scalp locations negatively correlated during NREM sleep with rCBF in the ventromedial prefrontal cortex, the basal forebrain, the striatum, the anterior insula, and the precuneus. These regions embrace the set of brain areas in which rCBF decreases during slow wave sleep (SWS) as compared to Rapid Eye Movement (REM) sleep and wakefulness (Maquet, P., Degueldre, C., Delfiore, G., Aerts, J., Peters, J.M., Luxen, A., Franck, G., 1997. Functional neuroanatomy of human slow wave sleep. J. Neurosci. 17, 2807-S2812), supporting the notion that delta activity is a valuable prominent feature of NREM sleep. A strong association was observed between rCBF in the ventromedial prefrontal regions and delta power, in agreement with electrophysiological studies. In contrast to the results of a previous PET study investigating the brain correlates of delta activity (Hofle, N., Paus, T., Reutens, D., Fiset, P., Gotman, J., Evans, A.C., Jones, B.E., 1997. Regional cerebral blood flow changes as a function of delta and spindle activity during slow wave sleep in humans. J. Neurosci. 17, 4800-4808), in which waking scans were mixed with NREM sleep scans, no correlation was found with thalamus activity. This latter result stresses the importance of an extra-thalamic delta rhythm among the synchronous NREM sleep oscillations. Consequently, this rCBF distribution might preferentially reflect a particular modulation of the cellular processes involved in the generation of cortical delta waves during NREM sleep.

The attracting power of the gaze of politicians is modulated by the personality and ideological attitude of their voters: a functional magnetic resonance imaging study.

PubMed

Cazzato, Valentina; Liuzza, Marco Tullio; Caprara, Gian Vittorio; Macaluso, Emiliano; Aglioti, Salvatore Maria

2015-10-01

Observing someone rapidly moving their eyes induces reflexive shifts of overt and covert attention in the onlooker. Previous studies have shown that this process can be modulated by the onlooker's personality, as well as by the social features of the person depicted in the cued face. Here, we investigated whether an individual's preference for social dominance orientation, in-group perceived similarity (PS), and political affiliation of the cued-face modulated neural activity within specific nodes of the social attention network. During functional magnetic resonance imaging, participants were requested to perform a gaze-following task to investigate whether the directional gaze of various Italian political personages might influence the oculomotor behaviour of in-group or out-group voters. After scanning, we acquired measures of PS in personality traits with each political personage and preference for social dominance orientation. Behavioural data showed that higher gaze interference for in-group than out-group political personages was predicted by a higher preference for social hierarchy. Higher blood oxygenation level-dependent activity in incongruent vs. congruent conditions was found in areas associated with orienting to socially salient events and monitoring response conflict, namely the left frontal eye field, right supramarginal gyrus, mid-cingulate cortex and left anterior insula. Interestingly, higher ratings of PS with the in-group and less preference for social hierarchy predicted increased activity in the left frontal eye field during distracting gaze movements of in-group as compared with out-group political personages. Our results suggest that neural activity in the social orienting circuit is modulated by higher-order social dimensions, such as in-group PS and individual differences in ideological attitudes. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Eye shape and the nocturnal bottleneck of mammals.

PubMed

Hall, Margaret I; Kamilar, Jason M; Kirk, E Christopher

2012-12-22

Most vertebrate groups exhibit eye shapes that vary predictably with activity pattern. Nocturnal vertebrates typically have large corneas relative to eye size as an adaptation for increased visual sensitivity. Conversely, diurnal vertebrates generally demonstrate smaller corneas relative to eye size as an adaptation for increased visual acuity. By contrast, several studies have concluded that many mammals exhibit typical nocturnal eye shapes, regardless of activity pattern. However, a recent study has argued that new statistical methods allow eye shape to accurately predict activity patterns of mammals, including cathemeral species (animals that are equally likely to be awake and active at any time of day or night). Here, we conduct a detailed analysis of eye shape and activity pattern in mammals, using a broad comparative sample of 266 species. We find that the eye shapes of cathemeral mammals completely overlap with nocturnal and diurnal species. Additionally, most diurnal and cathemeral mammals have eye shapes that are most similar to those of nocturnal birds and lizards. The only mammalian clade that diverges from this pattern is anthropoids, which have convergently evolved eye shapes similar to those of diurnal birds and lizards. Our results provide additional evidence for a nocturnal 'bottleneck' in the early evolution of crown mammals.

Eye shape and the nocturnal bottleneck of mammals

PubMed Central

Hall, Margaret I.; Kamilar, Jason M.; Kirk, E. Christopher

2012-01-01

Most vertebrate groups exhibit eye shapes that vary predictably with activity pattern. Nocturnal vertebrates typically have large corneas relative to eye size as an adaptation for increased visual sensitivity. Conversely, diurnal vertebrates generally demonstrate smaller corneas relative to eye size as an adaptation for increased visual acuity. By contrast, several studies have concluded that many mammals exhibit typical nocturnal eye shapes, regardless of activity pattern. However, a recent study has argued that new statistical methods allow eye shape to accurately predict activity patterns of mammals, including cathemeral species (animals that are equally likely to be awake and active at any time of day or night). Here, we conduct a detailed analysis of eye shape and activity pattern in mammals, using a broad comparative sample of 266 species. We find that the eye shapes of cathemeral mammals completely overlap with nocturnal and diurnal species. Additionally, most diurnal and cathemeral mammals have eye shapes that are most similar to those of nocturnal birds and lizards. The only mammalian clade that diverges from this pattern is anthropoids, which have convergently evolved eye shapes similar to those of diurnal birds and lizards. Our results provide additional evidence for a nocturnal ‘bottleneck’ in the early evolution of crown mammals. PMID:23097513

The Genome of the “Great Speciator” Provides Insights into Bird Diversification

PubMed Central

Cornetti, Luca; Valente, Luis M.; Dunning, Luke T.; Quan, Xueping; Black, Richard A.; Hébert, Olivier; Savolainen, Vincent

2015-01-01

Among birds, white-eyes (genus Zosterops) have diversified so extensively that Jared Diamond and Ernst Mayr referred to them as the “great speciator.” The Zosterops lineage exhibits some of the fastest rates of species diversification among vertebrates, and its members are the most prolific passerine island colonizers. We present a high-quality genome assembly for the silvereye (Zosterops lateralis), a white-eye species consisting of several subspecies distributed across multiple islands. We investigate the genetic basis of rapid diversification in white-eyes by conducting genomic analyses at varying taxonomic levels. First, we compare the silvereye genome with those of birds from different families and searched for genomic features that may be unique to Zosterops. Second, we compare the genomes of different species of white-eyes from Lifou island (South Pacific), using whole genome resequencing and restriction site associated DNA. Third, we contrast the genomes of two subspecies of silvereye that differ in plumage color. In accordance with theory, we show that white-eyes have high rates of substitutions, gene duplication, and positive selection relative to other birds. Below genus level, we find that genomic differentiation accumulates rapidly and reveals contrasting demographic histories between sympatric species on Lifou, indicative of past interspecific interactions. Finally, we highlight genes possibly involved in color polymorphism between the subspecies of silvereye. By providing the first whole-genome sequence resources for white-eyes and by conducting analyses at different taxonomic levels, we provide genomic evidence underpinning this extraordinary bird radiation. PMID:26338191

CXCL1, but not IL-6, significantly impacts intraocular inflammation during infection.

PubMed

Parkunan, Salai Madhumathi; Randall, C Blake; Astley, Roger A; Furtado, Glaucia C; Lira, Sergio A; Callegan, Michelle C

2016-11-01

During intraocular bacterial infections, the primary innate responders are neutrophils, which may cause bystander damage to the retina or perturb the clarity of the visual axis. We hypothesized that cytokine IL-6 and chemokine CXCL1 contributed to rapid neutrophil recruitment during Bacillus cereus endophthalmitis, a severe form of intraocular infection that is characterized by explosive inflammation and retinal damage that often leads to rapid vision loss. To test this hypothesis, we compared endophthalmitis pathogenesis in C57BL/6J, IL-6 -/- , and CXCL1 -/- mice. Bacterial growth in eyes of CXCL1 -/- , IL-6 -/- , and C67BL/6J mice was similar. Retinal function retention was greater in eyes of IL-6 -/- and CXCL1 -/- mice compared with that of C57BL/6J, despite these eyes having similar bacterial burdens. Neutrophil influx into eyes of CXCL1 -/- mice was reduced to a greater degree compared with that of eyes of IL6 -/- mice. Histology confirmed significantly less inflammation in eyes of CXCL1 -/- mice, but similar degrees of inflammation in IL6 -/- and C57BL/6J eyes. Because inflammation was reduced in eyes of infected CXCL1 -/- mice, we tested the efficacy of anti-CXCL1 in B. cereus endophthalmitis. Retinal function was retained to a greater degree and there was less overall inflammation in eyes treated with anti-CXCL1, which suggested that anti-CXCL1 may have therapeutic efficacy in limiting inflammation during B. cereus endophthalmitis. Taken together, our results indicate that absence of IL-6 did not affect overall pathogenesis of endophthalmitis. In contrast, absence of CXCL1, in CXCL1 -/- mice or after anti-CXCL1 treatment, led to an improved clinical outcome. Our findings suggest a potential benefit in targeting CXCL1 to control inflammation during B. cereus and perhaps other types of intraocular infections. © Society for Leukocyte Biology.

Rapid Eye Movement Sleep Behavior Disorder in Paraneoplastic Cerebellar Degeneration: Improvement with Immunotherapy.

PubMed

Vale, Thiago Cardoso; Fernandes do Prado, Lucila Bizari; do Prado, Gilmar Fernandes; Povoas Barsottini, Orlando Graziani; Pedroso, José Luiz

2016-01-01

To report two female patients with paraneoplastic cerebellar degeneration (PCD) related to breast cancer that presented with rapid eye movement-sleep behavior disorder (RBD) and improved sleep symptoms with immunotherapy. The two patients were evaluated through clinical scale and polysomnography before and after therapy with intravenous immunoglobulin. RBD was successfully treated with immunotherapy in both patients. Score on the RBD screening questionnaire dropped from 10 to 1 or 0, allied with the normalization of polysomnographic findings. A marked improvement in RBD after immunotherapy in PCD raises the hypothesis that secondary RBD may be an immune-mediated sleep disorder. © 2016 Associated Professional Sleep Societies, LLC.

Rapid eye movement sleep behaviour disorder symptomatic of a brain stem cavernoma.

PubMed

Felix, Sandra; Thobois, Stephane; Peter-Derex, Laure

2016-04-01

A 75-year-old man complained of excessive daytime sleepiness (EDS), difficulty falling asleep and nocturnal agitation during sleep. Restless legs syndrome (RLS) was diagnosed and treated. Because of persistent EDS, snoring and nycturia, a nocturnal polysomnography (PSG) was performed. PSG showed high sleep fragmentation related to a moderate to severe obstructive sleep apnea syndrome. Continuous positive airway pressure treatment (CPAP) was proposed. Because of the persistence of abnormal nocturnal behaviours, characterized by screaming, punching and falling out of bed, a video-PSG with CPAP treatment was performed. The recording showed typical chin electromyography (EMG) activity increase associated with violent movements during rapid eye movement (REM) sleep, suggesting REM sleep behaviour disorders (RBD). Clinical neurological examination found no parkinsonian syndrome, no dysautonomic sign and no neurological focal sign. Dopamine transporter imaging [123I-FP-CIT single photon emission computed tomography (SPECT)] did not find any presynaptic dopaminergic pathways degeneration. Brain magnetic resonance imaging showed a vascular lesion suggestive of cavernoma located in the pons. The present case illustrates the complexity of sleep disturbance diagnosis with a possible entanglement of aetiologies responsible for nocturnal agitation, and confirms that an isolated pons cavernoma should be considered among the rare causes of RBD. © 2016 European Sleep Research Society.

Why are seizures rare in rapid eye movement sleep? Review of the frequency of seizures in different sleep stages.

PubMed

Ng, Marcus; Pavlova, Milena

2013-01-01

Since the formal characterization of sleep stages, there have been reports that seizures may preferentially occur in certain phases of sleep. Through ascending cholinergic connections from the brainstem, rapid eye movement (REM) sleep is physiologically characterized by low voltage fast activity on the electroencephalogram, REMs, and muscle atonia. Multiple independent studies confirm that, in REM sleep, there is a strikingly low proportion of seizures (~1% or less). We review a total of 42 distinct conventional and intracranial studies in the literature which comprised a net of 1458 patients. Indexed to duration, we found that REM sleep was the most protective stage of sleep against focal seizures, generalized seizures, focal interictal discharges, and two particular epilepsy syndromes. REM sleep had an additional protective effect compared to wakefulness with an average 7.83 times fewer focal seizures, 3.25 times fewer generalized seizures, and 1.11 times fewer focal interictal discharges. In further studies REM sleep has also demonstrated utility in localizing epileptogenic foci with potential translation into postsurgical seizure freedom. Based on emerging connectivity data in sleep, we hypothesize that the influence of REM sleep on seizures is due to a desynchronized EEG pattern which reflects important connectivity differences unique to this sleep stage.

The kinematics of far-near re-fixation saccades

PubMed Central

Misslisch, H.

2015-01-01

We have analyzed the three-dimensional spatiotemporal characteristics of saccadic refixations between far and near targets in three behaviorally trained rhesus monkeys. The kinematics underlying these rapid eye movements can be accurately described by rotations of the eyes in four different planes, namely, first disconjugate rotations in the horizontal plane of regard converging the eyes toward the near target, followed by rotations in each eye's vertical direction plane, and finally, disconjugate rotations in a common frontoparallel plane. This compounded rotation of the eye was underlying an initially fast-rising variable torsion that typically overshot the final torsion, which the eyes attained at the time of target acquisition. The torsion consisted of a coarse, widely varying component of opposite polarity in the two eyes, which contained a more robust, much smaller modulation that sharply increased toward the end of saccades. The reorientation of the eyes in torsion depended on each eye's azimuth, elevation, and target distance. We conclude that refixation saccades are generated by motor commands that control ocular torsion in concert with the saccade generator, which operates in Donders-Listing kinematics underlying Listing's law. PMID:25717167

Longitudinal Changes of Angle Configuration in Primary Angle-Closure Suspects

PubMed Central

Jiang, Yuzhen; Chang, Dolly S.; Zhu, Haogang; Khawaja, Anthony P.; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M.

2015-01-01

Objective To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Design Longitudinal cohort study. Participants Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Methods Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Main Outcome Measures Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. Results No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8–1.6) in treated eyes and 1.6°/year (95% CI, 1.3–2.0) in untreated eyes (P<0.001). Conclusions Angle width of treated eyes increased markedly after LPI, remained stable for 6 months, and then decreased significantly by 18 months after LPI. Untreated eyes experienced a more consistent and rapid decrease in angle width over the same time period. PMID:24835757

Impact of Dry Eye Symptoms and Daily Activities in a Modern Office.

PubMed

van Tilborg, Mirjam M; Murphy, Paul J; Evans, Katharine S

2017-06-01

Modern offices and the use of electronic devices are increasing factors in work-related eye symptoms. However, symptoms of eye fatigue or dry eye sensation can be mixed and confusing. This study surveys the eye symptoms reported during a working day at modern offices to investigate the possible inhibition on daily work activities. Two online digital surveys were sent to three different work locations, by direct e-mail. Survey A consisted of 14 questions that investigated eye symptoms experienced during daily activities at work and the impact on daily activities. Survey B consisted of four general questions, the Dutch Ocular Surface Disease Index, the Work Productivity and Activity Index, and the Illness Perception Questionnaire. A total of 505 participants completed survey A, and 213 completed survey B. The participants reported that a high proportion of their day was spent working on a computer (60%). The majority experienced an air draft (79.1%) and had no adjustable light (81.5%) at their workspace. Dry eye-related symptoms were reported at a significantly higher frequency at work than at home (P < .001). Up to 70% experienced some inhibition of daily activity at work due to eye symptoms, with more than 5% experiencing symptoms most or all of the time. Indoor environment, work environment, and general health were perceived as the main reasons for developing dry eye. Compared with males, females showed a statistically significant higher Ocular Surface Disease Index score (P < .001) and experienced more inhibition and adverse effects on daily life and work productivity. This investigation shows that dry eye symptoms have a negative impact on daily activities at work. These findings suggest that multidisciplinary understanding of the negative impact of dry eye by a range of specialists will be of help in managing work-related dry eye.

Anti-inflammatory and Antihistaminic Study of a Unani Eye Drop Formulation.

PubMed

Abdul, Latif; Abdul, Razique; Sukul, R R; Nazish, Siddiqui

2010-01-01

The Unani eye drop is an ophthalmic formulation prepared for its beneficial effects in the inflammatory and allergic conditions of the eyes. In the present study, the Unani eye drop formulation was prepared and investigated for its anti-inflammatory and antihistaminic activity, using in vivo and in vitro experimental models respectively. The Unani eye drop formulation exhibited significant anti-inflammatory activity in turpentine liniment-induced ocular inflammation in rabbits. The preparation also showed antihistaminic activity in isolated guinea-pig ileum. The anti-inflammatory and antihistaminic activity of eye drop may be due to presence of active ingredients in the formulation. Although there are many drugs in Unani repository which are mentioned in classical books or used in Unani clinical practice effectively in treatment of eye diseases by various Unani physicians. Inspite of the availability of vast literature, there is a dearth of commercial Unani ocular preparations. So, keeping this in mind, the eye drop formulation was prepared and its anti-inflammatory and antihistaminic activity was carried out in animal models. Thus, in view of the importance of alternative anti-inflammatory and antiallergic drugs, it becomes imperative to bring these indigenous drugs to the front foot and evaluate their activities.

Impaired Activation of Visual Attention Network for Motion Salience Is Accompanied by Reduced Functional Connectivity between Frontal Eye Fields and Visual Cortex in Strabismic Amblyopia

PubMed Central

Wang, Hao; Crewther, Sheila G.; Liang, Minglong; Laycock, Robin; Yu, Tao; Alexander, Bonnie; Crewther, David P.; Wang, Jian; Yin, Zhengqin

2017-01-01

Strabismic amblyopia is now acknowledged to be more than a simple loss of acuity and to involve alterations in visually driven attention, though whether this applies to both stimulus-driven and goal-directed attention has not been explored. Hence we investigated monocular threshold performance during a motion salience-driven attention task involving detection of a coherent dot motion target in one of four quadrants in adult controls and those with strabismic amblyopia. Psychophysical motion thresholds were impaired for the strabismic amblyopic eye, requiring longer inspection time and consequently slower target speed for detection compared to the fellow eye or control eyes. We compared fMRI activation and functional connectivity between four ROIs of the occipital-parieto-frontal visual attention network [primary visual cortex (V1), motion sensitive area V5, intraparietal sulcus (IPS) and frontal eye fields (FEF)], during a suprathreshold version of the motion-driven attention task, and also a simple goal-directed task, requiring voluntary saccades to targets randomly appearing along a horizontal line. Activation was compared when viewed monocularly by controls and the amblyopic and its fellow eye in strabismics. BOLD activation was weaker in IPS, FEF and V5 for both tasks when viewing through the amblyopic eye compared to viewing through the fellow eye or control participants' non-dominant eye. No difference in V1 activation was seen between the amblyopic and fellow eye, nor between the two eyes of control participants during the motion salience task, though V1 activation was significantly less through the amblyopic eye than through the fellow eye and control group non-dominant eye viewing during the voluntary saccade task. Functional correlations of ROIs within the attention network were impaired through the amblyopic eye during the motion salience task, whereas this was not the case during the voluntary saccade task. Specifically, FEF showed reduced functional connectivity with visual cortical nodes during the motion salience task through the amblyopic eye, despite suprathreshold detection performance. This suggests that the reduced ability of the amblyopic eye to activate the frontal components of the attention networks may help explain the aberrant control of visual attention and eye movements in amblyopes. PMID:28484381

Attention switching during scene perception: how goals influence the time course of eye movements across advertisements.

PubMed

Wedel, Michel; Pieters, Rik; Liechty, John

2008-06-01

Eye movements across advertisements express a temporal pattern of bursts of respectively relatively short and long saccades, and this pattern is systematically influenced by activated scene perception goals. This was revealed by a continuous-time hidden Markov model applied to eye movements of 220 participants exposed to 17 ads under a free-viewing condition, and a scene-learning goal (ad memorization), a scene-evaluation goal (ad appreciation), a target-learning goal (product learning), or a target-evaluation goal (product evaluation). The model reflects how attention switches between two states--local and global--expressed in saccades of shorter and longer amplitude on a spatial grid with 48 cells overlaid on the ads. During the 5- to 6-s duration of self-controlled exposure to ads in the magazine context, attention predominantly started in the local state and ended in the global state, and rapidly switched about 5 times between states. The duration of the local attention state was much longer than the duration of the global state. Goals affected the frequency of switching between attention states and the duration of the local, but not of the global, state. (c) 2008 APA, all rights reserved

The effects of left and right monocular viewing on hemispheric activation.

PubMed

Wang, Chao; Burtis, D Brandon; Ding, Mingzhou; Mo, Jue; Williamson, John B; Heilman, Kenneth M

2018-03-01

Prior research has revealed that whereas activation of the left hemisphere primarily increases the activity of the parasympathetic division of the autonomic nervous system, right-hemisphere activation increases the activity of the sympathetic division. In addition, each hemisphere primarily receives retinocollicular projections from the contralateral eye. A prior study reported that pupillary dilation was greater with left- than with right-eye monocular viewing. The goal of this study was to test the alternative hypotheses that this asymmetric pupil dilation with left-eye viewing was induced by activation of the right-hemispheric-mediated sympathetic activity, versus a reduction of left-hemisphere-mediated parasympathetic activity. Thus, this study was designed to learn whether there are changes in hemispheric activation, as measured by alteration of spontaneous alpha activity, during right versus left monocular viewing. High-density electroencephalography (EEG) was recorded from healthy participants viewing a crosshair with their right, left, or both eyes. There was a significantly less alpha power over the right hemisphere's parietal-occipital area with left and binocular viewing than with right-eye monocular viewing. The greater relative reduction of right-hemisphere alpha activity during left than during right monocular viewing provides further evidence that left-eye viewing induces greater increase in right-hemisphere activation than does right-eye viewing.

Evaluation of treatment for dry eye with 2-hydroxyestradiol using a dry eye rat model.

PubMed

Higuchi, Akihiro; Oonishi, Erina; Kawakita, Tetsuya; Tsubota, Kazuo

2016-01-01

2-hydroxy estradiol (2-OHE2) is a catechol derivative of 17β -Estradiol (E2) and it is synthesized from E2 catalyzed by cytochrome P4501A1. Previous studies reported that 2-OHE2 is a physiologic antioxidant in lipoproteins, liver microsomes, and the brain. Catechol derivatives show an anti-inflammatory effect through the inhibition of prostaglandin endoperoxide synthase (PGS) activity. Corneal erosion caused by dry eye is related to an increase in oxidative stress and inflammation in ocular surface cells. We investigated the therapeutic effects of 2-OHE2 on corneal damage caused by dry eye. Steroidal radical scavenging activity was confirmed through the electron spin resonance (ESR) method. PGS activity was measured using the COX Fluorescent Activity Assay Kit. To evaluate the effect of 2-OHE2 on the treatment for dry eye, 2-OHE2 was applied as an eye drop experiment using dry eye model rats. 2-OHE2 scavenged tyrosyl radical and possibly suppressed oxidative stress in corneal epithelial cells. In addition, 2-OHE2 inhibited PGS activity, and 2-OHE2 is probably a competitive inhibitor of PGS. Corneal PGS activity was upregulated in the dry eye group. Therefore, 2-OHE2 eye drops improved corneal erosion in dry eye model rats. 2-OHE2 is a candidate for the treatment of dry eye through the suppression of inflammation and oxidative stress in the cornea.

Photokinesis and Djopsin gene expression analysis during the regeneration of planarian eyes.

PubMed

Dong, Zimei; Yuwen, Yanqing; Sima, Yingxu; Dong, Yanping; Zhan, Huina; Chen, Guangwen; Liu, Dezeng

2017-03-01

Planarians provide the ideal model for studying eye development, with their simple eye structure and exceptionally rapid regeneration. Here, we observed the eye morphogenesis, photophobic behavior, spectral sensitivity and expression pattern of Djopsin in the freshwater planarian Dugesia japonica. The results showed that: (i) Djopsin encoding the putative protein belonged to the rhabdomeric opsins group and displayed high conservation during animal evolution; (ii) planarians displayed diverse photophobic response to different visible wavelengths and were more sensitive to light blue (495 nm) and yellow (635 nm); (iii) the morphogenesis and functional recovery of eyes were related to the expression pattern of Djopsin during head regeneration; and (iv) Djopsin gene plays a major role in functional recovery during eye regeneration and visual system maintenance in adult planarians. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Intraocular pressure in the smallest primate aging model: the gray mouse lemur.

PubMed

Dubicanac, Marko; Joly, Marine; Strüve, Julia; Nolte, Ingo; Mestre-Francés, Nadine; Verdier, Jean-Michel; Zimmermann, Elke

2018-05-01

The aim of this study was to assess the practicability of common tonometers used in veterinary medicine for rapid intraocular pressure (IOP) screening, to calibrate IOP values gained by the tonometers, and to define a reference IOP value for the healthy eye in a new primate model for aging research, the gray mouse lemur. TonoVet ® and the TonoPen ™ measurements were calibrated manometrically in healthy enucleated eyes of mouse lemurs euthanized for veterinary reasons. For comparison of the practicability of both tonometers as a rapid IOP assessment tool for living mouse lemurs, the IOP of 24 eyes of 12 animals held in the hand was measured. To define a standard reference value for IOP in mouse lemurs, 258 healthy animals were measured using the TonoVet ® . Intraocular pressure measurements for the TonoVet ® can be corrected using the formula: y = 0.981 + (1.962*TonoVet ® value), and those for the TonoPen ™ using that of y = 5.38 + (1.426*TonoPen ™ value). The calibrated IOP for a healthy mouse lemur eye was 20.3 ± 2.8 mmHg. The TonoVet ® showed advantages in practicability, for example, small corneal contact area, short and painless corneal contact, shortened total time spent on investigation, as well as the more accurate measured values. IOP measurements of healthy mouse lemur eyes were not affected by age, sex, eye side, or colony. Tonometry using TonoVet ® is the more practicable assessment tool for IOP measurement of the tiny eyes of living mouse lemurs. Pathological deviations can be identified based on the described reference value. © 2016 American College of Veterinary Ophthalmologists.

Evaluation of active and passive transport processes in corneas extracted from preserved rabbit eyes.

PubMed

Majumdar, Soumyajit; Hingorani, Tushar; Srirangam, Ramesh

2010-04-01

In vitro transcorneal permeability studies are an important screening tool in drug development. The objective of this research is to examine the feasibility of using corneas isolated from preserved rabbit eyes as a model for permeability evaluation. Eyes from male New Zealand White rabbits were used immediately or were stored overnight in phosphate-buffered saline (PBS) or Hanks balanced salt solution (HBSS) over wet ice. Integrity of isolated corneas was evaluated by measuring the TEER and by determining the permeability of paracellular and transcellular markers. Active transport was assessed by measuring transcorneal permeability of selected amino acids. Esterase activity was estimated using p-nitrophenyl assay. In all cases, corneas from freshly enucleated eyes were compared to those isolated from the day-old preserved eyes. Transcellular and paracellular passive diffusion was not affected by the storage medium and observed to be similar in the fresh and preserved eye models. However, amino acid transporters demonstrated lower functional activity in corneas excised from eyes preserved in PBS. Moreover, preserved eyes displayed almost 1.5-fold lower esterase activity in the corneal tissue. Thus, corneas isolated from day-old eyes, preserved in HBSS, closely mimics freshly excised rabbit corneas in terms of both active and passive transport characteristics but possesses slightly reduced enzymatic activity. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

[Emphasis on standardization and refinement in the diagnosis and treatment of dry eye].

PubMed

Liu, Z G

2017-09-11

Dry eye is the second most common ocular disease. In China, the incidence rate of dry eye has reached 21% to 30%, and dry eye patients have accounted for more than 30% of the total ophthalmology outpatients. Dry eye has become a common health problem that affects the working efficiency and life quality of Chinese people. Over the past decade, due to the rapid development of diagnostic equipments and new treatments for dry eye, dry eye has become one of the areas with greatest concerns in ophthalmology, and many eye institutions have set up their dry eye clinics. Although the diagnosis and treatment of dry eye has been improved in recent years, the awareness of dry eye in Chinese ophthalmologists is still too simple. In the diagnosis, the interrogation and basic examination are not given enough attention, and we are over-relying on equipments. Clinical examination and instrument operation also have not been standardized. This article emphasizes that we should pay attention to the interrogation, basic examination and standardization of clinical examination and equipment operation in diagnosing dry eye. The treatment regimen should be mostly refined and optimized to be individualized and comprehensive based on the causes, types and severity of dry eye. In addition, the physical and adjuvant therapy of dry eye should be given sufficient attention and applied reasonably. (Chin J Ophthalmol, 2017, 53: 641-644) .

Effect of passengers' active head tilt and opening/closure of eyes on motion sickness in lateral acceleration environment of cars.

PubMed

Wada, Takahiro; Yoshida, Keigo

2016-08-01

This study examined the effect of passengers' active head-tilt and eyes-open/eyes-closed conditions on the severity of motion sickness in the lateral acceleration environment of cars. In the centrifugal head-tilt condition, participants intentionally tilted their heads towards the centrifugal force, whereas in the centripetal head-tilt condition, the participants tilted their heads against the centrifugal acceleration. The eyes-open and eyes-closed cases were investigated for each head-tilt condition. In the experimental runs, the sickness rating in the centripetal head-tilt condition was significantly lower than that in the centrifugal head-tilt condition. Moreover, the sickness rating in the eyes-open condition was significantly lower than that in the eyes-closed condition. The results suggest that an active head-tilt motion against the centrifugal acceleration reduces the severity of motion sickness both in the eyes-open and eyes-closed conditions. They also demonstrate that the eyes-open condition significantly reduces the motion sickness even when the head-tilt strategy is used. Practitioner Summary: Little is known about the effect of head-tilt strategies on motion sickness. This study investigated the effects of head-tilt direction and eyes-open/eyes-closed conditions on motion sickness during slalom automobile driving. Passengers' active head tilt towards the centripetal direction and the eyes-open condition greatly reduce the severity of motion sickness.

Measurement and correction of transverse chromatic offsets for multi-wavelength retinal microscopy in the living eye.

PubMed

Harmening, Wolf M; Tiruveedhula, Pavan; Roorda, Austin; Sincich, Lawrence C

2012-09-01

A special challenge arises when pursuing multi-wavelength imaging of retinal tissue in vivo, because the eye's optics must be used as the main focusing elements, and they introduce significant chromatic dispersion. Here we present an image-based method to measure and correct for the eye's transverse chromatic aberrations rapidly, non-invasively, and with high precision. We validate the technique against hyperacute psychophysical performance and the standard chromatic human eye model. In vivo correction of chromatic dispersion will enable confocal multi-wavelength images of the living retina to be aligned, and allow targeted chromatic stimulation of the photoreceptor mosaic to be performed accurately with sub-cellular resolution.

Functional imaging reveals rapid reorganization of cortical activity after parietal inactivation in monkeys

PubMed Central

Wilke, Melanie; Kagan, Igor; Andersen, Richard A.

2012-01-01

Impairments of spatial awareness and decision making occur frequently as a consequence of parietal lesions. Here we used event-related functional MRI (fMRI) in monkeys to investigate rapid reorganization of spatial networks during reversible pharmacological inactivation of the lateral intraparietal area (LIP), which plays a role in the selection of eye movement targets. We measured fMRI activity in control and inactivation sessions while monkeys performed memory saccades to either instructed or autonomously chosen spatial locations. Inactivation caused a reduction of contralesional choices. Inactivation effects on fMRI activity were anatomically and functionally specific and mainly consisted of: (i) activity reduction in the upper bank of the superior temporal sulcus (temporal parietal occipital area) for single contralesional targets, especially in the inactivated hemisphere; and (ii) activity increase accompanying contralesional choices between bilateral targets in several frontal and parieto-temporal areas in both hemispheres. There was no overactivation for ipsilesional targets or choices in the intact hemisphere. Task-specific effects of LIP inactivation on blood oxygen level-dependent activity in the temporal parietal occipital area underline the importance of the superior temporal sulcus for spatial processing. Furthermore, our results agree only partially with the influential interhemispheric competition model of spatial neglect and suggest an additional component of interhemispheric cooperation in the compensation of neglect deficits. PMID:22562793

PC-based high-speed video-oculography for measuring rapid eye movements in mice.

PubMed

Sakatani, Tomoya; Isa, Tadashi

2004-05-01

We newly developed an infrared video-oculographic system for on-line tracking of the eye position in awake and head-fixed mice, with high temporal resolution (240 Hz). The system consists of a commercially available high-speed CCD camera and an image processing software written in LabVIEW run on IBM-PC with a plug-in video grabber board. This software calculates the center and area of the pupil by fitting circular function to the pupil boundary, and allows robust and stable tracking of the eye position in small animals like mice. On-line calculation is performed to obtain reasonable circular fitting of the pupil boundary even if a part of the pupil is covered with shadows or occluded by eyelids or corneal reflections. The pupil position in the 2-D video plane is converted to the rotation angle of the eyeball by estimating its rotation center based on the anatomical eyeball model. By this recording system, it is possible to perform quantitative analysis of rapid eye movements such as saccades in mice. This will provide a powerful tool for analyzing molecular basis of oculomotor and cognitive functions by using various lines of mutant mice.

Caffeine increases the velocity of rapid eye movements in unfatigued humans.

PubMed

Connell, Charlotte J W; Thompson, Benjamin; Turuwhenua, Jason; Hess, Robert F; Gant, Nicholas

2017-08-01

Caffeine is a widely used dietary stimulant that can reverse the effects of fatigue on cognitive, motor and oculomotor function. However, few studies have examined the effect of caffeine on the oculomotor system when homeostasis has not been disrupted by physical fatigue. This study examined the influence of a moderate dose of caffeine on oculomotor control and visual perception in participants who were not fatigued. Within a placebo-controlled crossover design, 13 healthy adults ingested caffeine (5 mg·kg -1 body mass) and were tested over 3 h. Eye movements, including saccades, smooth pursuit and optokinetic nystagmus, were measured using infrared oculography. Caffeine was associated with higher peak saccade velocities (472 ± 60° s -1 ) compared to placebo (455 ± 62° s -1 ). Quick phases of optokinetic nystagmus were also significantly faster with caffeine, whereas pursuit eye movements were unchanged. Non-oculomotor perceptual tasks (global motion and global orientation processing) were unaffected by caffeine. These results show that oculomotor control is modulated by a moderate dose of caffeine in unfatigued humans. These effects are detectable in the kinematics of rapid eye movements, whereas pursuit eye movements and visual perception are unaffected. Oculomotor functions may be sensitive to changes in central catecholamines mediated via caffeine's action as an adenosine antagonist, even when participants are not fatigued.

Improving eye safety in citrus harvest crews through the acceptance of personal protective equipment, community-based participatory research, social marketing, and community health workers.

PubMed

Tovar-Aguilar, J Antonio; Monaghan, Paul F; Bryant, Carol A; Esposito, Andrew; Wade, Mark; Ruiz, Omar; McDermott, Robert J

2014-01-01

For the last 10 years, the Partnership for Citrus Workers Health (PCWH) has been an evidence-based intervention program that promotes the adoption of protective eye safety equipment among Spanish-speaking farmworkers of Florida. At the root of this program is the systematic use of community-based preventive marketing (CBPM) and the training of community health workers (CHWs) among citrus harvester using popular education. CBPM is a model that combines the organizational system of community-based participatory research (CBPR) and the strategies of social marketing. This particular program relied on formative research data using a mixed-methods approach and a multilevel stakeholder analysis that allowed for rapid dissemination, effective increase of personal protective equipment (PPE) usage, and a subsequent impact on adoptive workers and companies. Focus groups, face-to-face interviews, surveys, participant observation, Greco-Latin square, and quasi-experimental tests were implemented. A 20-hour popular education training produced CHWs that translated results of the formative research to potential adopters and also provided first aid skills for eye injuries. Reduction of injuries is not limited to the use of safety glasses, but also to the adoption of timely intervention and regular eye hygiene. Limitations include adoption in only large companies, rapid decline of eye safety glasses without consistent intervention, technological limitations of glasses, and thorough cost-benefit analysis.

Sensitivity to image recurrence across eye-movement-like image transitions through local serial inhibition in the retina

PubMed Central

Krishnamoorthy, Vidhyasankar; Weick, Michael; Gollisch, Tim

2017-01-01

Standard models of stimulus encoding in the retina postulate that image presentations activate neurons according to the increase of preferred contrast inside the receptive field. During natural vision, however, images do not arrive in isolation, but follow each other rapidly, separated by sudden gaze shifts. We here report that, contrary to standard models, specific ganglion cells in mouse retina are suppressed after a rapid image transition by changes in visual patterns across the transition, but respond with a distinct spike burst when the same pattern reappears. This sensitivity to image recurrence depends on opposing effects of glycinergic and GABAergic inhibition and can be explained by a circuit of local serial inhibition. Rapid image transitions thus trigger a mode of operation that differs from the processing of simpler stimuli and allows the retina to tag particular image parts or to detect transition types that lead to recurring stimulus patterns. DOI: http://dx.doi.org/10.7554/eLife.22431.001 PMID:28230526

[Electromyography Analysis of Rapid Eye Movement Sleep Behavior Disorder].

PubMed

Nakano, Natsuko; Kinoshita, Fumiya; Takada, Hiroki; Nakayama, Meiho

2018-01-01

Polysomnography (PSG), which records physiological phenomena including brain waves, breathing status, and muscle tonus, is useful for the diagnosis of sleep disorders as a gold standard. However, measurement and analysis are complex for several specific sleep disorders, such as rapid eye movement (REM) sleep behavior disorder (RBD). Usually, brain waves during REM sleep indicate an awakening pattern under relaxed conditions of skeletal and antigravity muscles. However, these muscles are activated during REM sleep when patients suffer from RBD. These activated muscle movements during REM, so-called REM without atonia (RWA) recorded by PSG, may be related to a neurodegenerative disease such as Parkinson's disease. Thus, careful analysis of RWA is significant not only physically, but also clinically. Commonly, manual viewing measurement analysis of RWA is time-consuming. Therefore, quantitative studies on RWA are rarely reported. A software program, developed from Microsoft Office Excel ® , was used to semiautomatically analyze the RWA ratio extracted from PSG to compare with manual viewing measurement analysis. In addition, a quantitative muscle tonus study was carried out to evaluate the effect of medication on RBD patients. Using this new software program, we were able to analyze RWA on the same cases in approximately 15 min as compared with 60 min in the manual viewing measurement analysis. This software program can not only quantify RWA easily but also identify RWA waves for either phasic or tonic bursts. We consider that this software program will support physicians and scientists in their future research on RBD. We are planning to offer this software program for free to physicians and scientists.

Enhanced emotional reactivity after selective REM sleep deprivation in humans: an fMRI study

PubMed Central

Rosales-Lagarde, Alejandra; Armony, Jorge L.; del Río-Portilla, Yolanda; Trejo-Martínez, David; Conde, Ruben; Corsi-Cabrera, Maria

2012-01-01

Converging evidence from animal and human studies suggest that rapid eye movement (REM) sleep modulates emotional processing. The aim of the present study was to explore the effects of selective REM sleep deprivation (REM-D) on emotional responses to threatening visual stimuli and their brain correlates using functional magnetic resonance imaging (fMRI). Twenty healthy subjects were randomly assigned to two groups: selective REM-D, by awakening them at each REM sleep onset, or non-rapid eye movement sleep interruptions (NREM-I) as control for potential non-specific effects of awakenings and lack of sleep. In a within-subject design, a visual emotional reactivity task was performed in the scanner before and 24 h after sleep manipulation. Behaviorally, emotional reactivity was enhanced relative to baseline (BL) in the REM deprived group only. In terms of fMRI signal, there was, as expected, an overall decrease in activity in the NREM-I group when subjects performed the task the second time, particularly in regions involved in emotional processing, such as occipital and temporal areas, as well as in the ventrolateral prefrontal cortex, involved in top-down emotion regulation. In contrast, activity in these areas remained the same level or even increased in the REM-D group, compared to their BL level. Taken together, these results suggest that lack of REM sleep in humans is associated with enhanced emotional reactivity, both at behavioral and neural levels, and thus highlight the specific role of REM sleep in regulating the neural substrates for emotional responsiveness. PMID:22719723

Intravitreal Adalimumab in Active Noninfectious Uveitis: A Pilot Study.

PubMed

Hamam, Rola N; Barikian, Anita W; Antonios, Rafic S; Abdulaal, Marwan R; Alameddine, Ramzi M; El Mollayess, Georges; Mansour, Ahmad M

2016-06-01

To evaluate the short-term efficacy of intravitreal adalimumab (IVA) for the treatment of eyes with active noninfectious uveitis. Consecutive eyes with active noninfectious uveitis were injected with IVA at 0, 2, then every 4 weeks for total of 26 weeks. Six out of 7 patients (12 of 13 eyes) completed 26 weeks of treatment. One patient (1 eye) failed treatment. Seven out of 12 eyes had improvement of ≥2 ETDRS lines. Three out of three eyes had resolution of anterior chamber cells. And 9 of 10 eyes with vitreous haze had zero haze at 26 weeks. Five out of 8 eyes with macular edema had complete resolution. Median fluorescein angiography score improved from 14 to 4 on last follow-up. IVA was effective in controlling the inflammation, decreasing the macular edema, and improving the best corrected visual acuity in the majority of eyes in this series.

The impact of diurnal sleep on the consolidation of a complex gross motor adaptation task

PubMed Central

Hoedlmoser, Kerstin; Birklbauer, Juergen; Schabus, Manuel; Eibenberger, Patrick; Rigler, Sandra; Mueller, Erich

2015-01-01

Diurnal sleep effects on consolidation of a complex, ecological valid gross motor adaptation task were examined using a bicycle with an inverse steering device. We tested 24 male subjects aged between 20 and 29 years using a between-subjects design. Participants were trained to adapt to the inverse steering bicycle during 45 min. Performance was tested before (TEST1) and after (TEST2) training, as well as after a 2 h retention interval (TEST3). During retention, participants either slept or remained awake. To assess gross motor performance, subjects had to ride the inverse steering bicycle 3 × 30 m straight-line and 3 × 30 m through a slalom. Beyond riding time, we sophisticatedly measured performance accuracy (standard deviation of steering angle) in both conditions using a rotatory potentiometer. A significant decrease of accuracy during straight-line riding after nap and wakefulness was shown. Accuracy during slalom riding remained stable after wakefulness but was reduced after sleep. We found that the duration of rapid eye movement sleep as well as sleep spindle activity are negatively related with gross motor performance changes over sleep. Together these findings suggest that the consolidation of adaptation to a new steering device does not benefit from a 2 h midday nap. We speculate that in case of strongly overlearned motor patterns such as normal cycling, diurnal sleep spindles and rapid eye movement sleep might even help to protect everyday needed skills, and to rapidly forget newly acquired, interfering and irrelevant material. PMID:25256866

Hypnotic activities of chamomile and passiflora extracts in sleep-disturbed rats.

PubMed

Shinomiya, Kazuaki; Inoue, Toshio; Utsu, Yoshiaki; Tokunaga, Shin; Masuoka, Takayoshi; Ohmori, Asae; Kamei, Chiaki

2005-05-01

In the present study, we investigated hypnotic activities of chamomile and passiflora extracts using sleep-disturbed model rats. A significant decrease in sleep latency was observed with chamomile extract at a dose of 300 mg/kg, while passiflora extract showed no effects on sleep latency even at a dose of 3000 mg/kg. No significant effects were observed with both herbal extracts on total times of wakefulness, non-rapid eye movement (non-REM) sleep and REM sleep. Flumazenil, a benzodiazepine receptor antagonist, at a dose of 3 mg/kg showed a significant antagonistic effect on the shortening in sleep latency induced by chamomile extract. No significant effects were observed with chamomile and passiflora extracts on delta activity during non-REM sleep. In conclusion, chamomile extract is a herb having benzodiazepine-like hypnotic activity.

Arousal mechanisms related to posture and locomotion: 1. Descending modulation.

PubMed

Garcia-Rill, Edgar; Homma, Yutaka; Skinner, Robert D

2004-01-01

Much of the controversy surrounding the induction of locomotion following stimulation of mesopontine sites, including the pedunculopontine nucleus (PPN), appears based on procedural differences, including stimulus onset, delay preceding stepping, and frequency of stimuli. The results reviewed in this chapter address these issues and provide novel information suggesting that descending projections from the PPN may exert a frequency-dependent effect. Stimulation at approximately 60 Hz (which induces prolonged tonic firing) may exercise a "push" towards locomotion (activation of pontine interneurons) as well as a "pull" away from decreased muscle tone (inhibiting giant pontine reticulospinal cells). Higher frequencies of stimulation (> 100 Hz, which induces phasic burst-like activity) may "push" towards decreases in muscle tone, including the atonia of rapid eye movement sleep (activating giant pontine reticulospinal cells).

Time delay between cardiac and brain activity during sleep transitions

NASA Astrophysics Data System (ADS)

Long, Xi; Arends, Johan B.; Aarts, Ronald M.; Haakma, Reinder; Fonseca, Pedro; Rolink, Jérôme

2015-04-01

Human sleep consists of wake, rapid-eye-movement (REM) sleep, and non-REM (NREM) sleep that includes light and deep sleep stages. This work investigated the time delay between changes of cardiac and brain activity for sleep transitions. Here, the brain activity was quantified by electroencephalographic (EEG) mean frequency and the cardiac parameters included heart rate, standard deviation of heartbeat intervals, and their low- and high-frequency spectral powers. Using a cross-correlation analysis, we found that the cardiac variations during wake-sleep and NREM sleep transitions preceded the EEG changes by 1-3 min but this was not the case for REM sleep transitions. These important findings can be further used to predict the onset and ending of some sleep stages in an early manner.

Traumatic brain injury and vestibulo-ocular function: current challenges and future prospects

PubMed Central

Wallace, Bridgett; Lifshitz, Jonathan

2016-01-01

Normal function of the vestibulo-ocular reflex (VOR) coordinates eye movement with head movement, in order to provide clear vision during motion and maintain balance. VOR is generated within the semicircular canals of the inner ear to elicit compensatory eye movements, which maintain stability of images on the fovea during brief, rapid head motion, otherwise known as gaze stability. Normal VOR function is necessary in carrying out activities of daily living (eg, walking and riding in a car) and is of particular importance in higher demand activities (eg, sports-related activities). Disruption or damage in the VOR can result in symptoms such as movement-related dizziness, blurry vision, difficulty maintaining balance with head movements, and even nausea. Dizziness is one of the most common symptoms following traumatic brain injury (TBI) and is considered a risk factor for a prolonged recovery. Assessment of the vestibular system is of particular importance following TBI, in conjunction with oculomotor control, due to the intrinsic neural circuitry that exists between the ocular and vestibular systems. The purpose of this article is to review the physiology of the VOR and the visual-vestibular symptoms associated with TBI and to discuss assessment and treatment guidelines for TBI. Current challenges and future prospects will also be addressed. PMID:28539811

Progressive outer retinal necrosis presenting as cherry red spot.

PubMed

Yiu, Glenn; Young, Lucy H

2012-10-01

To report a case of progressive outer retinal necrosis (PORN) presenting as a cherry red spot. Case report. A 53-year-old woman with recently diagnosed HIV and varicella-zoster virus (VZV) aseptic meningitis developed rapid sequential vision loss in both eyes over 2 months. Her exam showed a "cherry red spot" in both maculae with peripheral atrophy and pigmentary changes, consistent with PORN. Due to her late presentation and the rapid progression of her condition, she quickly developed end-stage vision loss in both eyes. PORN should be considered within the differential diagnosis of a "cherry red spot." Immune-deficient patients with a history of herpetic infection who present with visual loss warrant prompt ophthalmological evaluation.

Rhythmic movement disorder (head banging) in an adult during rapid eye movement sleep.

PubMed

Anderson, Kirstie N; Smith, Ian E; Shneerson, John M

2006-06-01

Sleep-related rhythmic movements (head banging or body rocking) are extremely common in normal infants and young children, but less than 5% of children over the age of 5 years old exhibit these stereotyped motor behaviors. They characteristically occur during drowsiness or sleep onset rather than in deep sleep or rapid eye movement (REM) sleep. We present a 27-year-old man with typical rhythmic movement disorder that had persisted into adult life and was restricted to REM sleep. This man is the oldest subject with this presentation reported to date and highlights the importance of recognizing this nocturnal movement disorder when it does occur in adults.

A look into hurricane Maria rapid intensification using Meteo-France's Arome-Antilles model.

NASA Astrophysics Data System (ADS)

Pilon, R.; Faure, G.; Dupont, T.; Chauvin, F.

2017-12-01

Category 5 Hurricane Maria created a string of humanitarian crises. It caused billions of dollars of damage over the Caribbean but is also one of the worst natural disaster in Dominica.The hurricane took approximately 29 hours to strengthen from a tropical storm to a major category 5 hurricane. Here we present real-time forecasts of high resolution (2.5 km) Arome-Antilles regional model forced by real-time ECMWF's Integrated Forecasting System. The model was able to relatively represent well the rapid intensification of the hurricane whether it was in timing or in location of the eye and strength of its eye wall.We will present an outline of results.

Metastatic intraocular hemangiopericytoma in a dog

PubMed Central

Pucket, Jonathan D.; Allbaugh, Rachel A.; Higginbotham, Mary L.; Rankin, Amy J.; Teixeira, Leandro

2017-01-01

A 10-year-old Labrador Retriever who had been undergoing therapy for a recurrent hemangiopericytoma of the right flank presented to the Kansas State University Ophthalmology service for evaluation of a painful left eye. Examination revealed secondary glaucoma and irreversible blindness of the affected eye and multifocal chorioretinal lesions in the fellow eye. Therapeutic and diagnostic enucleation of the left eye was performed and histopathologic examination demonstrated the presence of a presumed metastatic spindle cell sarcoma. Further immunohistochemical staining confirmed the intraocular neoplasia to be metastatic spread from the previously removed flank mass. Rapid progression in size and number of chorioretinal lesions in the right eye was noted in the post-operative period until the patient was euthanized one month after surgery. This case report is the first to document intraocular metastasis of hemangiopericytoma in a veterinary patient. PMID:28652979

Metastatic intraocular hemangiopericytoma in a dog.

PubMed

Pucket, Jonathan D; Allbaugh, Rachel A; Higginbotham, Mary L; Rankin, Amy J; Teixeira, Leandro

2017-01-01

A 10-year-old Labrador Retriever who had been undergoing therapy for a recurrent hemangiopericytoma of the right flank presented to the Kansas State University Ophthalmology service for evaluation of a painful left eye. Examination revealed secondary glaucoma and irreversible blindness of the affected eye and multifocal chorioretinal lesions in the fellow eye. Therapeutic and diagnostic enucleation of the left eye was performed and histopathologic examination demonstrated the presence of a presumed metastatic spindle cell sarcoma. Further immunohistochemical staining confirmed the intraocular neoplasia to be metastatic spread from the previously removed flank mass. Rapid progression in size and number of chorioretinal lesions in the right eye was noted in the post-operative period until the patient was euthanized one month after surgery. This case report is the first to document intraocular metastasis of hemangiopericytoma in a veterinary patient.

Stratified coastal ocean interactions with tropical cyclones

PubMed Central

Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

2016-01-01

Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. PMID:26953963

Effort Not Speed Characterizes Comprehension of Spoken Sentences by Older Adults with Mild Hearing Impairment

PubMed Central

Ayasse, Nicole D.; Lash, Amanda; Wingfield, Arthur

2017-01-01

In spite of the rapidity of everyday speech, older adults tend to keep up relatively well in day-to-day listening. In laboratory settings older adults do not respond as quickly as younger adults in off-line tests of sentence comprehension, but the question is whether comprehension itself is actually slower. Two unique features of the human eye were used to address this question. First, we tracked eye-movements as 20 young adults and 20 healthy older adults listened to sentences that referred to one of four objects pictured on a computer screen. Although the older adults took longer to indicate the referenced object with a cursor-pointing response, their gaze moved to the correct object as rapidly as that of the younger adults. Second, we concurrently measured dilation of the pupil of the eye as a physiological index of effort. This measure revealed that although poorer hearing acuity did not slow processing, success came at the cost of greater processing effort. PMID:28119598

Effort Not Speed Characterizes Comprehension of Spoken Sentences by Older Adults with Mild Hearing Impairment.

PubMed

Ayasse, Nicole D; Lash, Amanda; Wingfield, Arthur

2016-01-01

In spite of the rapidity of everyday speech, older adults tend to keep up relatively well in day-to-day listening. In laboratory settings older adults do not respond as quickly as younger adults in off-line tests of sentence comprehension, but the question is whether comprehension itself is actually slower. Two unique features of the human eye were used to address this question. First, we tracked eye-movements as 20 young adults and 20 healthy older adults listened to sentences that referred to one of four objects pictured on a computer screen. Although the older adults took longer to indicate the referenced object with a cursor-pointing response, their gaze moved to the correct object as rapidly as that of the younger adults. Second, we concurrently measured dilation of the pupil of the eye as a physiological index of effort. This measure revealed that although poorer hearing acuity did not slow processing, success came at the cost of greater processing effort.

An Analysis of the Time Course of Lexical Processing During Reading.

PubMed

Sheridan, Heather; Reichle, Erik D

2016-04-01

Reingold, Reichle, Glaholt, and Sheridan (2012) reported a gaze-contingent eye-movement experiment in which survival-curve analyses were used to examine the effects of word frequency, the availability of parafoveal preview, and initial fixation location on the time course of lexical processing. The key results of these analyses suggest that lexical processing begins very rapidly (after approximately 120 ms) and is supported by substantial parafoveal processing (more than 100 ms). Because it is not immediately obvious that these results are congruent with the theoretical assumption that words are processed and identified in a strictly serial manner, we attempted to simulate the experiment using the E-Z Reader model of eye-movement control (Reichle, 2011). These simulations were largely consistent with the empirical results, suggesting that parafoveal processing does play an important functional role by allowing lexical processing to occur rapidly enough to mediate direct control over when the eyes move during reading. Copyright © 2015 Cognitive Science Society, Inc.

The neural correlates of dreaming.

PubMed

Siclari, Francesca; Baird, Benjamin; Perogamvros, Lampros; Bernardi, Giulio; LaRocque, Joshua J; Riedner, Brady; Boly, Melanie; Postle, Bradley R; Tononi, Giulio

2017-06-01

Consciousness never fades during waking. However, when awakened from sleep, we sometimes recall dreams and sometimes recall no experiences. Traditionally, dreaming has been identified with rapid eye-movement (REM) sleep, characterized by wake-like, globally 'activated', high-frequency electroencephalographic activity. However, dreaming also occurs in non-REM (NREM) sleep, characterized by prominent low-frequency activity. This challenges our understanding of the neural correlates of conscious experiences in sleep. Using high-density electroencephalography, we contrasted the presence and absence of dreaming in NREM and REM sleep. In both NREM and REM sleep, reports of dream experience were associated with local decreases in low-frequency activity in posterior cortical regions. High-frequency activity in these regions correlated with specific dream contents. Monitoring this posterior 'hot zone' in real time predicted whether an individual reported dreaming or the absence of dream experiences during NREM sleep, suggesting that it may constitute a core correlate of conscious experiences in sleep.

Driver fatigue detection based on eye state.

PubMed

Lin, Lizong; Huang, Chao; Ni, Xiaopeng; Wang, Jiawen; Zhang, Hao; Li, Xiao; Qian, Zhiqin

2015-01-01

Nowadays, more and more traffic accidents occur because of driver fatigue. In order to reduce and prevent it, in this study, a calculation method using PERCLOS (percentage of eye closure time) parameter characteristics based on machine vision was developed. It determined whether a driver's eyes were in a fatigue state according to the PERCLOS value. The overall workflow solutions included face detection and tracking, detection and location of the human eye, human eye tracking, eye state recognition, and driver fatigue testing. The key aspects of the detection system incorporated the detection and location of human eyes and driver fatigue testing. The simplified method of measuring the PERCLOS value of the driver was to calculate the ratio of the eyes being open and closed with the total number of frames for a given period. If the eyes were closed more than the set threshold in the total number of frames, the system would alert the driver. Through many experiments, it was shown that besides the simple detection algorithm, the rapid computing speed, and the high detection and recognition accuracies of the system, the system was demonstrated to be in accord with the real-time requirements of a driver fatigue detection system.

The vestibulo-ocular reflex of the squirrel monkey during eccentric rotation and roll tilt

NASA Technical Reports Server (NTRS)

Merfeld, D. M.; Young, L. R.

1995-01-01

The vestibulo-ocular reflexes (VOR) are determined not only by angular acceleration, but also by the presence of gravity and linear acceleration. This phenomenon was studied by measuring three-dimensional nystagmic eye movements, with implanted search coils, in six male squirrel monkeys during eccentric rotation. Monkeys were rotated in the dark at a constant velocity of 200 degrees/s (centrally or 79 cm off axis) with the axis of rotation always aligned with gravity and the spinal axis of the upright monkeys. The monkey's orientation (facing-motion or back-to-motion) had a dramatic influence on the VOR. These experiments show that: (a) the axis of eye rotation always shifted toward alignment with gravito-inertial force; (b) the peak value of horizontal slow phase eye velocity was greater with the monkey facing-motion than with back-to-motion; and (c) the time constant of horizontal eye movement decay was smaller with the monkey facing-motion than with back-to-motion. All of these findings were statistically significant and consistent across monkeys. In another set of tests, the same monkeys were rapidly tilted about their naso-occipital (roll) axis. Tilted orientations of 45 degrees and 90 degrees were maintained for 1 min. Other than a compensatory angular VOR during the angular rotation, no consistent eye velocity response was observed during or following the tilt for any of the six monkeys. The absence of any eye movement response following tilt weighs against the possibility that translational linear VOR responses are due to simple high-pass filtering of the otolith signals. The VOR response during eccentric rotation was divided into the more familiar angular VOR and linear VOR components. The angular component is known to depend upon semicircular canal dynamics and central influences. The linear component of the response decays rapidly with a mean duration of only 6.6 s, while the axis of eye rotation rapidly aligns (< 10 s) with gravito-inertial force. These results are consistent with the hypothesis that the measurement of gravito-inertial force by the otolith organs is resolved into central estimates of linear acceleration and gravity, such that the central estimate of gravitational force minus the central estimate of linear acceleration approximately equals the otolith measurement of gravito-inertial force.

Evolution of crystallins for a role in the vertebrate eye lens.

PubMed

Slingsby, Christine; Wistow, Graeme J; Clark, Alice R

2013-04-01

The camera eye lens of vertebrates is a classic example of the re-engineering of existing protein components to fashion a new device. The bulk of the lens is formed from proteins belonging to two superfamilies, the α-crystallins and the βγ-crystallins. Tracing their ancestry may throw light on the origin of the optics of the lens. The α-crystallins belong to the ubiquitous small heat shock proteins family that plays a protective role in cellular homeostasis. They form enormous polydisperse oligomers that challenge modern biophysical methods to uncover the molecular basis of their assembly structure and chaperone-like protein binding function. It is argued that a molecular phenotype of a dynamic assembly suits a chaperone function as well as a structural role in the eye lens where the constraint of preventing protein condensation is paramount. The main cellular partners of α-crystallins, the β- and γ-crystallins, have largely been lost from the animal kingdom but the superfamily is hugely expanded in the vertebrate eye lens. Their structures show how a simple Greek key motif can evolve rapidly to form a complex array of monomers and oligomers. Apart from remaining transparent, a major role of the partnership of α-crystallins with β- and γ-crystallins in the lens is to form a refractive index gradient. Here, we show some of the structural and genetic features of these two protein superfamilies that enable the rapid creation of different assembly states, to match the rapidly changing optical needs among the various vertebrates. Copyright © 2013 The Protein Society.

Evolution of crystallins for a role in the vertebrate eye lens

PubMed Central

Slingsby, Christine; Wistow, Graeme J; Clark, Alice R

2013-01-01

The camera eye lens of vertebrates is a classic example of the re-engineering of existing protein components to fashion a new device. The bulk of the lens is formed from proteins belonging to two superfamilies, the α-crystallins and the βγ-crystallins. Tracing their ancestry may throw light on the origin of the optics of the lens. The α-crystallins belong to the ubiquitous small heat shock proteins family that plays a protective role in cellular homeostasis. They form enormous polydisperse oligomers that challenge modern biophysical methods to uncover the molecular basis of their assembly structure and chaperone-like protein binding function. It is argued that a molecular phenotype of a dynamic assembly suits a chaperone function as well as a structural role in the eye lens where the constraint of preventing protein condensation is paramount. The main cellular partners of α-crystallins, the β- and γ-crystallins, have largely been lost from the animal kingdom but the superfamily is hugely expanded in the vertebrate eye lens. Their structures show how a simple Greek key motif can evolve rapidly to form a complex array of monomers and oligomers. Apart from remaining transparent, a major role of the partnership of α-crystallins with β- and γ-crystallins in the lens is to form a refractive index gradient. Here, we show some of the structural and genetic features of these two protein superfamilies that enable the rapid creation of different assembly states, to match the rapidly changing optical needs among the various vertebrates. PMID:23389822

A Change of Possible Neurological and Psychological Significance Within the First Week of Neonate Life: Sleeping REM Rate.

ERIC Educational Resources Information Center

Minard, James; And Others

The percentage of rapid eye movement (REM) during sleep is substantially greater in neonates (infants in first month after birth) than in other children or adults. It was hypothesized that REM rate may decline as rates of many response sequences do when repeatedly elicited. Electrical recordings of eye movements were obtained from a 3-day-old male…

The Circadian Clock Gene Csnk1e Regulates Rapid Eye Movement Sleep Amount, and Nonrapid Eye Movement Sleep Architecture in Mice

PubMed Central

Zhou, Lili; Bryant, Camron D.; Loudon, Andrew; Palmer, Abraham A.; Vitaterna, Martha Hotz; Turek, Fred W.

2014-01-01

Study Objectives: Efforts to identify the genetic basis of mammalian sleep have included quantitative trait locus (QTL) mapping and gene targeting of known core circadian clock genes. We combined three different genetic approaches to identify and test a positional candidate sleep gene — the circadian gene casein kinase 1 epsilon (Csnk1e), which is located in a QTL we identified for rapid eye movement (REM) sleep on chromosome 15. Measurements and Results: Using electroencephalographic (EEG) and electromyographic (EMG) recordings, baseline sleep was examined in a 12-h light:12-h dark (LD 12:12) cycle in mice of seven genotypes, including Csnk1etau/tau and Csnk1e-/- mutant mice, Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice, and their respective wild-type littermate control mice. Additionally, Csnk1etau/tau and wild-type mice were examined in constant darkness (DD). Csnk1etau/tau mutant mice and both Csnk1eB6.D2 and Csnk1eD2.B6 congenic mice showed significantly higher proportion of sleep time spent in REM sleep during the dark period than wild-type controls — the original phenotype for which the QTL on chromosome 15 was identified. This phenotype persisted in Csnk1etau/tau mice while under free-running DD conditions. Other sleep phenotypes observed in Csnk1etau/tau mice and congenics included a decreased number of bouts of nonrapid eye movement (NREM) sleep and an increased average NREM sleep bout duration. Conclusions: These results demonstrate a role for Csnk1e in regulating not only the timing of sleep, but also the REM sleep amount and NREM sleep architecture, and support Csnk1e as a causal gene in the sleep QTL on chromosome 15. Citation: Zhou L; Bryant CD; Loudon A; Palmer AA; Vitaterna MH; Turek FW. The circadian clock gene Csnk1e regulates rapid eye movement sleep amount, and nonrapid eye movement sleep architecture in mice. SLEEP 2014;37(4):785-793. PMID:24744456

RapidEye constellation relative radiometric accuracy measurement using lunar images

NASA Astrophysics Data System (ADS)

Steyn, Joe; Tyc, George; Beckett, Keith; Hashida, Yoshi

2009-09-01

The RapidEye constellation includes five identical satellites in Low Earth Orbit (LEO). Each satellite has a 5-band (blue, green, red, red-edge and near infrared (NIR)) multispectral imager at 6.5m GSD. A three-axes attitude control system allows pointing the imager of each satellite at the Moon during lunations. It is therefore possible to image the Moon from near identical viewing geometry within a span of 80 minutes with each one of the imagers. Comparing the radiometrically corrected images obtained from each band and each satellite allows a near instantaneous relative radiometric accuracy measurement and determination of relative gain changes between the five imagers. A more traditional terrestrial vicarious radiometric calibration program has also been completed by MDA on RapidEye. The two components of this program provide for spatial radiometric calibration ensuring that detector-to-detector response remains flat, while a temporal radiometric calibration approach has accumulated images of specific dry dessert calibration sites. These images are used to measure the constellation relative radiometric response and make on-ground gain and offset adjustments in order to maintain the relative accuracy of the constellation within +/-2.5%. A quantitative comparison between the gain changes measured by the lunar method and the terrestrial temporal radiometric calibration method is performed and will be presented.

Shorter duration of non-rapid eye movement sleep slow waves in EphA4 knockout mice.

PubMed

Freyburger, Marlène; Poirier, Gaétan; Carrier, Julie; Mongrain, Valérie

2017-10-01

Slow waves occurring during non-rapid eye movement sleep have been associated with neurobehavioural performance and memory. In addition, the duration of previous wakefulness and sleep impacts characteristics of these slow waves. However, molecular mechanisms regulating the dynamics of slow-wave characteristics remain poorly understood. The EphA4 receptor regulates glutamatergic transmission and synaptic plasticity, which have both been linked to sleep slow waves. To investigate if EphA4 regulates slow-wave characteristics during non-rapid eye movement sleep, we compared individual parameters of slow waves between EphA4 knockout mice and wild-type littermates under baseline conditions and after a 6-h sleep deprivation. We observed that, compared with wild-type mice, knockout mice display a shorter duration of positive and negative phases of slow waves under baseline conditions and after sleep deprivation. However, the mutation did not change slow-wave density, amplitude and slope, and did not affect the sleep deprivation-dependent changes in slow-wave characteristics, suggesting that EphA4 is not involved in the response to elevated sleep pressure. Our present findings suggest a role for EphA4 in shaping cortical oscillations during sleep that is independent from sleep need. © 2017 European Sleep Research Society.

Beneficial effect of daidzin in dry eye rat model through the suppression of inflammation and oxidative stress in the cornea.

PubMed

Xiao, Fan; Cui, Hua; Zhong, Xiao

2018-05-01

Present investigation evaluates the effect of daidzin in dry eye rat model through the suppression of inflammation and oxidative stress in the cornea. Briefly, electron spine resonance was used for the estimation of radical scavenging activity of daidzin and COX Fluorescent Activity Assay Kit was used for the estimation of PGS activity. Dry eye rat model was developed by removing the lacrimal gland and effect of daidzin was evaluated in dry eye rat model by estimating the fluorescein score, tear volume and expressions of heme oxigenase (HO-1), TNF α, Interlukin 6 (IL-6), matrix metallopeptidase 9 (MMP-9) and PGS-2. Result of the present study suggested that daidzin possess tyrosyl radical scavenging activity and thereby decreases the oxidative stress. Activity of PGS significantly increases in dry eye which was inhibited by daidzin treatment due to competitive inhibition of PGS. It also recovers the tear volume in dry eye rat model in which lacrimal gland was removed. Thus corneal erosion was improved by daidzin in dry eye rat model. Thus present study concludes that treatment with daidzin protects the cornea in dry eye rat model by suppression inflammation and oxidative stress.

EEG Brain Activity in Dynamic Health Qigong Training: Same Effects for Mental Practice and Physical Training?

PubMed

Henz, Diana; Schöllhorn, Wolfgang I

2017-01-01

In recent years, there has been significant uptake of meditation and related relaxation techniques, as a means of alleviating stress and fostering an attentive mind. Several electroencephalogram (EEG) studies have reported changes in spectral band frequencies during Qigong meditation indicating a relaxed state. Much less is reported on effects of brain activation patterns induced by Qigong techniques involving bodily movement. In this study, we tested whether (1) physical Qigong training alters EEG theta and alpha activation, and (2) mental practice induces the same effect as a physical Qigong training. Subjects performed the dynamic Health Qigong technique Wu Qin Xi (five animals) physically and by mental practice in a within-subjects design. Experimental conditions were randomized. Two 2-min (eyes-open, eyes-closed) EEG sequences under resting conditions were recorded before and immediately after each 15-min exercise. Analyses of variance were performed for spectral power density data. Increased alpha power was found in posterior regions in mental practice and physical training for eyes-open and eyes-closed conditions. Theta power was increased after mental practice in central areas in eyes-open conditions, decreased in fronto-central areas in eyes-closed conditions. Results suggest that mental, as well as physical Qigong training, increases alpha activity and therefore induces a relaxed state of mind. The observed differences in theta activity indicate different attentional processes in physical and mental Qigong training. No difference in theta activity was obtained in physical and mental Qigong training for eyes-open and eyes-closed resting state. In contrast, mental practice of Qigong entails a high degree of internalized attention that correlates with theta activity, and that is dependent on eyes-open and eyes-closed resting state.

Longitudinal changes of angle configuration in primary angle-closure suspects: the Zhongshan Angle-Closure Prevention Trial.

PubMed

Jiang, Yuzhen; Chang, Dolly S; Zhu, Haogang; Khawaja, Anthony P; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M; He, Mingguang; Friedman, David S; Foster, Paul J

2014-09-01

To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Longitudinal cohort study. Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8-1.6) in treated eyes and 1.6°/year (95% CI, 1.3-2.0) in untreated eyes (P<0.001). Angle width of treated eyes increased markedly after LPI, remained stable for 6 months, and then decreased significantly by 18 months after LPI. Untreated eyes experienced a more consistent and rapid decrease in angle width over the same time period. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Culture, gaze and the neural processing of fear expressions

PubMed Central

Franklin, Robert G.; Rule, Nicholas O.; Freeman, Jonathan B.; Kveraga, Kestutis; Hadjikhani, Nouchine; Yoshikawa, Sakiko; Ambady, Nalini

2010-01-01

The direction of others’ eye gaze has important influences on how we perceive their emotional expressions. Here, we examined differences in neural activation to direct- versus averted-gaze fear faces as a function of culture of the participant (Japanese versus US Caucasian), culture of the stimulus face (Japanese versus US Caucasian), and the relation between the two. We employed a previously validated paradigm to examine differences in neural activation in response to rapidly presented direct- versus averted-fear expressions, finding clear evidence for a culturally determined role of gaze in the processing of fear. Greater neural responsivity was apparent to averted- versus direct-gaze fear in several regions related to face and emotion processing, including bilateral amygdalae, when posed on same-culture faces, whereas greater response to direct- versus averted-gaze fear was apparent in these same regions when posed on other-culture faces. We also found preliminary evidence for intercultural variation including differential responses across participants to Japanese versus US Caucasian stimuli, and to a lesser degree differences in how Japanese and US Caucasian participants responded to these stimuli. These findings reveal a meaningful role of culture in the processing of eye gaze and emotion, and highlight their interactive influences in neural processing. PMID:20019073

Differentiation between Vergence and Saccadic Functional Activity within the Human Frontal Eye Fields and Midbrain Revealed through fMRI

PubMed Central

Alkan, Yelda; Biswal, Bharat B.; Alvarez, Tara L.

2011-01-01

Purpose Eye movement research has traditionally studied solely saccade and/or vergence eye movements by isolating these systems within a laboratory setting. While the neural correlates of saccadic eye movements are established, few studies have quantified the functional activity of vergence eye movements using fMRI. This study mapped the neural substrates of vergence eye movements and compared them to saccades to elucidate the spatial commonality and differentiation between these systems. Methodology The stimulus was presented in a block design where the ‘off’ stimulus was a sustained fixation and the ‘on’ stimulus was random vergence or saccadic eye movements. Data were collected with a 3T scanner. A general linear model (GLM) was used in conjunction with cluster size to determine significantly active regions. A paired t-test of the GLM beta weight coefficients was computed between the saccade and vergence functional activities to test the hypothesis that vergence and saccadic stimulation would have spatial differentiation in addition to shared neural substrates. Results Segregated functional activation was observed within the frontal eye fields where a portion of the functional activity from the vergence task was located anterior to the saccadic functional activity (z>2.3; p<0.03). An area within the midbrain was significantly correlated with the experimental design for the vergence but not the saccade data set. Similar functional activation was observed within the following regions of interest: the supplementary eye field, dorsolateral prefrontal cortex, ventral lateral prefrontal cortex, lateral intraparietal area, cuneus, precuneus, anterior and posterior cingulates, and cerebellar vermis. The functional activity from these regions was not different between the vergence and saccade data sets assessed by analyzing the beta weights of the paired t-test (p>0.2). Conclusion Functional MRI can elucidate the differences between the vergence and saccade neural substrates within the frontal eye fields and midbrain. PMID:22073141

Use of protective eyewear in U.S. adults: results from the 2002 national health interview survey.

PubMed

Forrest, Kimberly Y Z; Cali, Joseph M; Cavill, Wilma J

2008-01-01

Many eye injuries occur because of not using protective eyewear. This study analyzed the 2002 National Health Interview Survey data to examine the rate of using protective eyewear during activities that could cause eye injuries outside the workplace and the correlates of not using protective eyewear among U.S. adults. The rate of participation in activities that could cause eye injuries and the rate of protective eyewear use during these activities were estimated using sample weights to yield national estimates. A total of 30,894 individuals in the survey provided valid data for the current analysis, which revealed that 29.3% of the U.S. adults reported engaging in activities that could cause an eye injury and 32.1% of those used eye protection while doing such activities. Males were more likely to use eye protection than females (34.7% vs. 25.2%). The age group of 18-24 years was least likely to use eye protection (15.3%). Other factors associated with not using protective eyewear included being black or other races, non-retired individuals, and those from low-income families (all p-values < 0.05). Use of protective eyewear during activities that could cause eye injuries was relatively low in the US adult population. Certain groups were at a higher risk for not using eye protection, including females, young adults aged 18-24 years, black or other races, and individuals with a low socioeconomic status. To promote eye safety, health education programs should target these high-risk groups.

Saccade-related activity in the prefrontal cortex: its role in eye movement control and cognitive functions

PubMed Central

Funahashi, Shintaro

2014-01-01

Prefrontal neurons exhibit saccade-related activity and pre-saccadic memory-related activity often encodes the directions of forthcoming eye movements, in line with demonstrated prefrontal contribution to flexible control of voluntary eye movements. However, many prefrontal neurons exhibit post-saccadic activity that is initiated well after the initiation of eye movement. Although post-saccadic activity has been observed in the frontal eye field, this activity is thought to be a corollary discharge from oculomotor centers, because this activity shows no directional tuning and is observed whenever the monkeys perform eye movements regardless of goal-directed or not. However, prefrontal post-saccadic activities exhibit directional tunings similar as pre-saccadic activities and show context dependency, such that post-saccadic activity is observed only when monkeys perform goal-directed saccades. Context-dependency of prefrontal post-saccadic activity suggests that this activity is not a result of corollary signals from oculomotor centers, but contributes to other functions of the prefrontal cortex. One function might be the termination of memory-related activity after a behavioral response is done. This is supported by the observation that the termination of memory-related activity coincides with the initiation of post-saccadic activity in population analyses of prefrontal activities. The termination of memory-related activity at the end of the trial ensures that the subjects can prepare to receive new and updated information. Another function might be the monitoring of behavioral performance, since the termination of memory-related activity by post-saccadic activity could be associated with informing the correctness of the response and the termination of the trial. However, further studies are needed to examine the characteristics of saccade-related activities in the prefrontal cortex and their functions in eye movement control and a variety of cognitive functions. PMID:25071482

Cyclic Alternating Pattern Associated with Catathrenia and Bruxism in a 10-Year-Old Patient.

PubMed

Villafuerte-Trisolini, Brian; Adrianzén-Álvarez, Fiorella; Duque, Kevin R; Palacios-García, Jimmy; Vizcarra-Escobar, Darwin

2017-03-15

Cyclic alternating pattern (CAP) is widely recognized as an expression of sleep instability in electroencephalogram activity during non-rapid eye movement sleep. We report a case with sequences of CAP followed by bruxism and catathrenia in a 10-y-old male patient with a diagnosis of attention deficit hyperactivity disorder in treatment with methylphenidate. We found CAP in 83.1% of all episodes of catathrenia, and the CAP rate was 12.8%. We propose to consider catathrenia as one of the sleep disorders that may be accompanied by CAP. © 2017 American Academy of Sleep Medicine

Electroencephalographic findings related with mild cognitive impairment in idiopathic rapid eye movement sleep behavior disorder.

PubMed

Sasai, Taeko; Matsuura, Masato; Inoue, Yuichi

2013-12-01

Mild cognitive impairment (MCI) and electroencephalographic (EEG) slowing have been reported as common findings of idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) and α-synucleinopathies. The objective of this study is to clarify the relation between MCI and physiological markers in iRBD. Cross-sectional study. Yoyogi Sleep Disorder Center. Thirty-one patients with iRBD including 17 younger patients with iRBD (younger than 70 y) and 17 control patients for the younger patients with iRBD. N/A. Montreal Cognitive Assessment (MoCA) and n-polysomnogram (PSG) were conducted of all participants. In patients with iRBD, the factors associated with MCI were explored among parameters of REM sleep without atonia (RWA), score of Sniffin' Sticks Test (threshold-discrimination-identification [TDI] score), RBD morbidity, and RBD severity evaluated with the Japanese version of the RBD questionnaire (RBDQ-JP). The younger iRBD group showed significantly lower alpha power during wake and lower MoCA score than the age-matched control group. MCI was detected in 13 of 17 patients (76.5%) on MoCA in this group. Among patients wtih iRBD, the MoCA score negatively correlated with age, proportion of slow wave sleep, TDI score, and EEG spectral power. Multiple regression analysis provided the following equation: MoCA score = 50.871-0.116*age -5.307*log (δ power during REM sleep) + 0.086*TDI score (R² = 0.598, P < 0.01). The standardized partial regression coefficients were -0.558 for age, -0.491 for log (δ power during REM sleep), and 0.357 for TDI score (F = 9.900, P < 0.001). Electroencephalographic slowing, especially during rapid eye movement sleep and olfactory dysfunction, was revealed to be associated with cognitive decline in idiopathic rapid eye movement sleep behavior disorder.

Normal Morning Melanin-Concentrating Hormone Levels and No Association with Rapid Eye Movement or Non-Rapid Eye Movement Sleep Parameters in Narcolepsy Type 1 and Type 2.

PubMed

Schrölkamp, Maren; Jennum, Poul J; Gammeltoft, Steen; Holm, Anja; Kornum, Birgitte R; Knudsen, Stine

2017-02-15

Other than hypocretin-1 (HCRT-1) deficiency in narcolepsy type 1 (NT1), the neurochemical imbalance of NT1 and narcolepsy type 2 (NT2) with normal HCRT-1 levels is largely unknown. The neuropeptide melanin-concentrating hormone (MCH) is mainly secreted during sleep and is involved in rapid eye movement (REM) and non-rapid eye movement (NREM) sleep regulation. Hypocretin neurons reciprocally interact with MCH neurons. We hypothesized that altered MCH secretion contributes to the symptoms and sleep abnormalities of narcolepsy and that this is reflected in morning cerebrospinal fluid (CSF) MCH levels, in contrast to previously reported normal evening/afternoon levels. Lumbar CSF and plasma were collected from 07:00 to 10:00 from 57 patients with narcolepsy (subtypes: 47 NT1; 10 NT2) diagnosed according to International Classification of Sleep Disorders, Third Edition (ICSD-3) and 20 healthy controls. HCRT-1 and MCH levels were quantified by radioimmunoassay and correlated with clinical symptoms, polysomnography (PSG), and Multiple Sleep Latency Test (MSLT) parameters. CSF and plasma MCH levels were not significantly different between narcolepsy patients regardless of ICSD-3 subtype, HCRT-1 levels, or compared to controls. CSF MCH and HCRT-1 levels were not significantly correlated. Multivariate regression models of CSF MCH levels, age, sex, and body mass index predicting clinical, PSG, and MSLT parameters did not reveal any significant associations to CSF MCH levels. Our study shows that MCH levels in CSF collected in the morning are normal in narcolepsy and not associated with the clinical symptoms, REM sleep abnormalities, nor number of muscle movements during REM or NREM sleep of the patients. We conclude that morning lumbar CSF MCH measurement is not an informative diagnostic marker for narcolepsy. © 2017 American Academy of Sleep Medicine

The Benefit of Directed Forgetting Persists After a Daytime Nap: The Role of Spindles and Rapid Eye Movement Sleep in the Consolidation of Relevant Memories.

PubMed

Blaskovich, Borbála; Szollosi, Ágnes; Gombos, Ferenc; Racsmány, Mihály; Simor, Péter

2017-03-01

We aimed to investigate the effect of directed forgetting instruction on memory retention after a 2-hour delay involving a daytime nap or an equivalent amount of time spent awake. We examined the associations between sleep-specific oscillations and the retention of relevant and irrelevant study materials. We applied a list-method directed forgetting paradigm manipulating the perceived relevance of previously encoded lists of words. Participants were randomly assigned to either a nap or an awake group, and to a remember or a forget subgroup. The remember and the forget subgroups were both instructed to study two consecutive lists of words, although, the forget subgroup was manipulated to forget the first list and memorize only the second one. Participants were 112 healthy individuals (44 men; Mage = 21.4 years, SD = 2.4). A significant directed forgetting effect emerged after a 2-hour delay both in the awake and sleep conditions; however, the effect was more pronounced within the sleep group. The benefit of directed forgetting, that is, relatively enhanced recall of relevant words in the forget group, was evidenced only in those participants that reached rapid eye movement (REM) phase. Non-rapid eye movement (NREM) sigma power was correlated with memory performance for the relevant (second) list, and sleep spindle amplitude was associated with the retention of both lists. These associations, however, were detected only within the forget subgroup. REM duration correlated with recall performance for the relevant (second) list within the forget subgroup, and with recall performance for the first list within the remember subgroup. A directed forgetting effect persists after a 2-hour delay spent awake or asleep. Spindle-related activity and subsequent REM sleep might selectively facilitate the processing of memories that are considered to be relevant for the future. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Fluctuation in visual acuity during soft toric contact lens wear.

PubMed

Chamberlain, Paul; Morgan, Philip B; Moody, Kurt J; Maldonado-Codina, Carole

2011-04-01

To quantify changes in visual acuity (VA) with soft toric contact lenses as a result of lens movement and/or rotational instability caused by versional eye movements. A novel chart for vision assessment at near (40 cm) for soft toric contact lenses (VANT chart),consisting of a central, color-coded logMAR panel and eight peripheral letter targets set on a white background measuring 60 × 40 cm was constructed. In the developmental phase of the work, 10 subjects (20 eyes) wore 2 toric lenses in random order, and the impact of rapid and delayed eye versions in 8 directions of gaze on VANT acuity was investigated. In phase 2, 35 subjects (68 eyes) wore 4 toric lenses in random order, and a streamlined clinical protocol using the VANT chart was implemented. Standard assessments of toric lens fit and distance VA were also performed. Testing in the first phase showed no difference for change in VA for rapid vs. delayed version movements, (p = 0.17) but acuity reduction was greater for diagonal compared with horizontal/vertical versions (p = 0.06). As such, testing in phase 2 proceeded using rapid, diagonal versions only. In this second phase, there were differences for low-contrast distance VA measures between lens types (p = 0.02) and for both VANT baseline acuity (p = 0.03) and postversion acuity (p = 0.04), but no differences were found between lenses for magnitude of vision loss (p = 0.91), which was about one line. No relationship was established between the magnitude of vision loss and measured rotational stability (p = 0.75). This work has demonstrated that conventional approaches to measuring VA do not fully replicate the "real world" experience of soft toric lens wearers. The VANT chart has shown that VA is reduced immediately after versional eye movements and suggests that more dynamic methods of assessing visual performance should be considered for soft toric contact lens wearers, especially given the apparent inability of lens stability measurements to predict visual performance.

In Vivo Confocal Intrinsic Optical Signal Identification of Localized Retinal Dysfunction

PubMed Central

Zhang, Qiu-Xiang; Lu, Rong-Wen; Curcio, Christine A.; Yao, Xin-Cheng

2012-01-01

Purpose. The purposes of this study were to investigate the physiological mechanism of stimulus-evoked fast intrinsic optical signals (IOSs) recorded in dynamic confocal imaging of the retina, and to demonstrate the feasibility of in vivo confocal IOS mapping of localized retinal dysfunctions. Methods. A rapid line-scan confocal ophthalmoscope was constructed to achieve in vivo confocal IOS imaging of frog (Rana pipiens) retinas at cellular resolution. In order to investigate the physiological mechanism of confocal IOS, comparative IOS and electroretinography (ERG) measurements were made using normal frog eyes activated by variable-intensity stimuli. A dynamic spatiotemporal filtering algorithm was developed to reject the contamination of hemodynamic changes on fast IOS recording. Laser-injured frog eyes were employed to test the potential of confocal IOS mapping of localized retinal dysfunctions. Results. Comparative IOS and ERG experiments revealed a close correlation between the confocal IOS and retinal ERG, particularly the ERG a-wave, which has been widely used to evaluate photoreceptor function. IOS imaging of laser-injured frog eyes indicated that the confocal IOS could unambiguously detect localized (30 μm) functional lesions in the retina before a morphological abnormality is detectable. Conclusions. The confocal IOS predominantly results from retinal photoreceptors, and can be used to map localized photoreceptor lesion in laser-injured frog eyes. We anticipate that confocal IOS imaging can provide applications in early detection of age-related macular degeneration, retinitis pigmentosa, and other retinal diseases that can cause pathological changes in the photoreceptors. PMID:23150616

CXCL1, but not IL-6, significantly impacts intraocular inflammation during infection

PubMed Central

Parkunan, Salai Madhumathi; Randall, C. Blake; Astley, Roger A.; Furtado, Glaucia C.; Lira, Sergio A.; Callegan, Michelle C.

2016-01-01

During intraocular bacterial infections, the primary innate responders are neutrophils, which may cause bystander damage to the retina or perturb the clarity of the visual axis. We hypothesized that cytokine IL-6 and chemokine CXCL1 contributed to rapid neutrophil recruitment during Bacillus cereus endophthalmitis, a severe form of intraocular infection that is characterized by explosive inflammation and retinal damage that often leads to rapid vision loss. To test this hypothesis, we compared endophthalmitis pathogenesis in C57BL/6J, IL-6−/−, and CXCL1−/− mice. Bacterial growth in eyes of CXCL1−/−, IL-6−/−, and C67BL/6J mice was similar. Retinal function retention was greater in eyes of IL-6−/− and CXCL1−/− mice compared with that of C57BL/6J, despite these eyes having similar bacterial burdens. Neutrophil influx into eyes of CXCL1−/− mice was reduced to a greater degree compared with that of eyes of IL6−/− mice. Histology confirmed significantly less inflammation in eyes of CXCL1−/− mice, but similar degrees of inflammation in IL6−/− and C57BL/6J eyes. Because inflammation was reduced in eyes of infected CXCL1−/− mice, we tested the efficacy of anti-CXCL1 in B. cereus endophthalmitis. Retinal function was retained to a greater degree and there was less overall inflammation in eyes treated with anti-CXCL1, which suggested that anti-CXCL1 may have therapeutic efficacy in limiting inflammation during B. cereus endophthalmitis. Taken together, our results indicate that absence of IL-6 did not affect overall pathogenesis of endophthalmitis. In contrast, absence of CXCL1, in CXCL1−/− mice or after anti-CXCL1 treatment, led to an improved clinical outcome. Our findings suggest a potential benefit in targeting CXCL1 to control inflammation during B. cereus and perhaps other types of intraocular infections. PMID:27286792

Incorporating Animation Concepts and Principles in STEM Education

ERIC Educational Resources Information Center

Harrison, Henry L., III; Hummell, Laura J.

2010-01-01

Animation is the rapid display of a sequence of static images that creates the illusion of movement. This optical illusion is often called perception of motion, persistence of vision, illusion of motion, or short-range apparent motion. The phenomenon occurs when the eye is exposed to rapidly changing still images, with each image being changed…

Rapid and coordinated processing of global motion images by local clusters of retinal ganglion cells.

PubMed

Matsumoto, Akihiro; Tachibana, Masao

2017-01-01

Even when the body is stationary, the whole retinal image is always in motion by fixational eye movements and saccades that move the eye between fixation points. Accumulating evidence indicates that the brain is equipped with specific mechanisms for compensating for the global motion induced by these eye movements. However, it is not yet fully understood how the retina processes global motion images during eye movements. Here we show that global motion images evoke novel coordinated firing in retinal ganglion cells (GCs). We simultaneously recorded the firing of GCs in the goldfish isolated retina using a multi-electrode array, and classified each GC based on the temporal profile of its receptive field (RF). A moving target that accompanied the global motion (simulating a saccade following a period of fixational eye movements) modulated the RF properties and evoked synchronized and correlated firing among local clusters of the specific GCs. Our findings provide a novel concept for retinal information processing during eye movements.

Best practice eye care models

PubMed Central

Qureshi, Babar M; Mansur, Rabiu; Al-Rajhi, Abdulaziz; Lansingh, Van; Eckert, Kristen; Hassan, Kunle; Ravilla, Thulasiraj; Muhit, Mohammad; Khanna, Rohit C; Ismat, Chaudhry

2012-01-01

Since the launching of Global Initiative, VISION 2020 “the Right to Sight” many innovative, practical and unique comprehensive eye care services provision models have evolved targeting the underserved populations in different parts of the World. At places the rapid assessment of the burden of eye diseases in confined areas or utilizing the key informants for identification of eye diseases in the communities are promoted for better planning and evidence based advocacy for getting / allocation of resources for eye care. Similarly for detection and management of diabetes related blindness, retinopathy of prematurity and avoidable blindness at primary level, the major obstacles are confronted in reaching to them in a cost effective manner and then management of the identified patients accordingly. In this regard, the concept of tele-ophthalmology model sounds to be the best solution. Whereas other models on comprehensive eye care services provision have been emphasizing on surgical output through innovative scales of economy that generate income for the program and ensure its sustainability, while guaranteeing treatment of the poorest of the poor. PMID:22944741

Rapid eye movement sleep behaviour disorder and striatal dopamine depletion in patients with Parkinson's disease.

PubMed

Chung, S J; Lee, Y; Lee, J J; Lee, P H; Sohn, Y H

2017-10-01

Rapid eye movement sleep behaviour disorder (RBD) is related to striatal dopamine depletion. This study was performed to confirm whether clinically probable RBD (cpRBD) in patients with Parkinson's disease (PD) is associated with a specific pattern of striatal dopamine depletion. A prospective survey was conducted using the RBD Screening Questionnaire (RBDSQ) in 122 patients with PD who had undergone dopamine transporter (DAT) positron emission tomography scan. Patients with cpRBD (RBDSQ ≥ 7) exhibited greater motor deficits, predominantly in the less-affected side and axial symptoms, and were prescribed higher levodopa-equivalent doses at follow-up than those without cpRBD (RBDSQ ≤ 4), despite their similar disease and treatment durations. Compared to patients without cpRBD, those with cpRBD showed lower DAT activities in the putamen, particularly in the less-affected side in all putaminal subregions, and a tendency to be lower in the ventral striatum. In addition, greater motor deficits in patients with cpRBD than in those without cpRBD remained significant after controlling for DAT binding in the putamen and other confounding variables. These results demonstrated that the presence of RBD in patients with PD is associated with different patterns of both motor deficit distribution and striatal DAT depletion, suggesting that the presence of RBD represents a distinct PD subtype with a malignant motor parkinsonism. © 2017 EAN.

Association of eye color and sex with basketball free throws by elementary school children.

PubMed

Patee, T; Frewen, M; Beer, J

1991-12-01

Dark-eyed individuals perform reactive activities better while light-eyed individuals generally perform self-paced activities better. There were 68 (21 dark- and 47 light-eyed) elementary school children who shot 5 practice and then 15 free throws from the free-throw line in a high school gym. There were no differences in performance between light- and dark-eyed children, but boys scored more free throws than girls.

Atypical cytomegalovirus retinitis in non-Hodgkin's lymphoma.

PubMed

Tyagi, Mudit; Ambiya, Vikas; Mathai, Annie; Narayanan, Raja

2015-08-03

A 54-year-old woman, a known case of non-Hodgkin's lymphoma (NHL) in complete remission, presented with floaters and diminution of vision in her left eye. The eye had vitritis with non-haemorrhagic retinitis mimicking intraocular lymphoma and acute retinal necrosis. A vitreous sample was positive for cytomegalovirus (CMV) and herpes simplex virus 1 (HSV-1) DNA by PCR. The possibility of intraocular lymphoma was not confirmed by the immunohistochemistry of the vitreous sample. The patient had a relapse of NHL along with rapid deterioration of vision in her left eye to no perception of light, due to optic nerve involvement. The right eye developed a new patch of focal haemorrhagic retinitis threatening the fovea. Based on the laboratory results and the clinical findings, she was successfully managed as a case of bilateral CMV retinitis and the vision in her right eye was salvaged. 2015 BMJ Publishing Group Ltd.

Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic

PubMed Central

Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

2016-01-01

Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment. PMID:26785293

Exceptional preservation of eye structure in arthropod visual predators from the Middle Jurassic.

PubMed

Vannier, Jean; Schoenemann, Brigitte; Gillot, Thomas; Charbonnier, Sylvain; Clarkson, Euan

2016-01-19

Vision has revolutionized the way animals explore their environment and interact with each other and rapidly became a major driving force in animal evolution. However, direct evidence of how ancient animals could perceive their environment is extremely difficult to obtain because internal eye structures are almost never fossilized. Here, we reconstruct with unprecedented resolution the three-dimensional structure of the huge compound eye of a 160-million-year-old thylacocephalan arthropod from the La Voulte exceptional fossil biota in SE France. This arthropod had about 18,000 lenses on each eye, which is a record among extinct and extant arthropods and is surpassed only by modern dragonflies. Combined information about its eyes, internal organs and gut contents obtained by X-ray microtomography lead to the conclusion that this thylacocephalan arthropod was a visual hunter probably adapted to illuminated environments, thus contradicting the hypothesis that La Voulte was a deep-water environment.

New Eye-Tracking Techniques May Revolutionize Mental Health Screening

DTIC Science & Technology

2015-11-04

health? Recent progress in eye-tracking tech- niques is opening new avenues for quanti - tative, objective, simple, inexpensive, and rapid evaluation ...to check with your doctor whether any corrective action should be taken. What if similar devices could be made available for the evaluation of mental... evaluations , especially for those disor- ders for which a clear chemical, genetic, morphological, physiological, or histologi- cal biomarker has not yet

A paper-based cantilever array sensor: Monitoring volatile organic compounds with naked eye.

PubMed

Fraiwan, Arwa; Lee, Hankeun; Choi, Seokheun

2016-09-01

Volatile organic compound (VOC) detection is critical for controlling industrial and commercial emissions, environmental monitoring, and public health. Simple, portable, rapid and low-cost VOC sensing platforms offer the benefits of on-site and real-time monitoring anytime and anywhere. The best and most practically useful approaches to monitoring would include equipment-free and power-free detection by the naked eye. In this work, we created a novel, paper-based cantilever sensor array that allows simple and rapid naked-eye VOC detection without the need for power, electronics or readout interface/equipment. This simple VOC detection method was achieved using (i) low-cost paper materials as a substrate and (ii) swellable thin polymers adhered to the paper. Upon exposure to VOCs, the polymer swelling adhered to the paper-based cantilever, inducing mechanical deflection that generated a distinctive composite pattern of the deflection angles for a specific VOC. The angle is directly measured by the naked eye on a 3-D protractor printed on a paper facing the cantilevers. The generated angle patterns are subjected to statistical algorithms (linear discriminant analysis (LDA)) to classify each VOC sample and selectively detect a VOC. We classified four VOC samples with 100% accuracy using LDA. Copyright © 2016 Elsevier B.V. All rights reserved.

EYE MOVEMENT RECORDING AND NONLINEAR DYNAMICS ANALYSIS – THE CASE OF SACCADES#

PubMed Central

Aştefănoaei, Corina; Pretegiani, Elena; Optican, L.M.; Creangă, Dorina; Rufa, Alessandra

2015-01-01

Evidence of a chaotic behavioral trend in eye movement dynamics was examined in the case of a saccadic temporal series collected from a healthy human subject. Saccades are highvelocity eye movements of very short duration, their recording being relatively accessible, so that the resulting data series could be studied computationally for understanding the neural processing in a motor system. The aim of this study was to assess the complexity degree in the eye movement dynamics. To do this we analyzed the saccadic temporal series recorded with an infrared camera eye tracker from a healthy human subject in a special experimental arrangement which provides continuous records of eye position, both saccades (eye shifting movements) and fixations (focusing over regions of interest, with rapid, small fluctuations). The semi-quantitative approach used in this paper in studying the eye functioning from the viewpoint of non-linear dynamics was accomplished by some computational tests (power spectrum, portrait in the state space and its fractal dimension, Hurst exponent and largest Lyapunov exponent) derived from chaos theory. A high complexity dynamical trend was found. Lyapunov largest exponent test suggested bi-stability of cellular membrane resting potential during saccadic experiment. PMID:25698889

Discussion of impact of relics activation on protection and utilization approaches-take the old summer palace as an example

NASA Astrophysics Data System (ADS)

Xiaoqi, J.

2015-08-01

As the popularization of cultural relics and the rapid development of cultural tourism industry, a large number of cultural relic tourism resources goes into public eyes. Activation of relics has became an important way for tourist to contact and understand culture relics. The way of how to properly interpret the historical sense and cultural uniqueness to the masses of tourists in order to achieve social service functions of relic resources has always been research focal point of site protection and utilization, so nowadays it has important significance to protection and utilization of heritage resources in our country. From the point of activation of relics and based on the analysis of resource characteristic, the paper in depth discuss ways of activation of relics of the Old Summer Palace, in order to provide reference for sustainable development of sites tourism in China.

Highly Sensitive Naked-Eye Assay for Enterovirus 71 Detection Based on Catalytic Nanoparticle Aggregation and Immunomagnetic Amplification.

PubMed

Xiong, Ling-Hong; He, Xuewen; Xia, Junjie; Ma, Hanwu; Yang, Fan; Zhang, Qian; Huang, Dana; Chen, Long; Wu, Chunli; Zhang, Xiaomin; Zhao, Zheng; Wan, Chengsong; Zhang, Renli; Cheng, Jinquan

2017-05-03

Development of sensitive, convenient, and cost-effective virus detection product is of great significance to meet the growing demand of clinical diagnosis at the early stage of virus infection. Herein, a naked-eye readout of immunoassay by means of virion bridged catalase-mediated in situ reduction of gold ions and growth of nanoparticles, has been successfully proposed for rapid visual detection of Enterovirus 71 (EV71). Through tailoring the morphologies of the produced gold nanoparticles (GNPs) varying between dispersion and aggregation, a distinguishing color changing was ready for observation. This colorimetric detection assay, by further orchestrating the efficient magnetic enrichment and the high catalytic activity of enzyme, is managed to realize highly sensitive detection of EV71 virions with the limit of detection (LOD) down to 0.65 ng/mL. Our proposed method showed a much lower LOD value than the commercial ELISA for EV71 virion detection. Comparing to the current clinical gold standard polymerase chain reaction (PCR) method, our strategy provided the same diagnostic outcomes after testing real clinical samples. Besides, this strategy has no need of complicated sample pretreatment or expensive instruments. Our presented naked-eye immunoassay method holds a promising prospect for the early detection of virus-infectious disease especially in resource-constrained settings.

Rapid Stress System Drives Chemical Transfer of Fear from Sender to Receiver

PubMed Central

de Groot, Jasper H. B.; Smeets, Monique A. M.; Semin, Gün R.

2015-01-01

Humans can register another person’s fear not only with their eyes and ears, but also with their nose. Previous research has demonstrated that exposure to body odors from fearful individuals elicited implicit fear in others. The odor of fearful individuals appears to have a distinctive signature that can be produced relatively rapidly, driven by a physiological mechanism that has remained unexplored in earlier research. The apocrine sweat glands in the armpit that are responsible for chemosignal production contain receptors for adrenalin. We therefore expected that the release of adrenalin through activation of the rapid stress response system (i.e., the sympathetic-adrenal medullary system) is what drives the release of fear sweat, as opposed to activation of the slower stress response system (i.e., hypothalamus-pituitary-adrenal axis). To test this assumption, sweat was sampled while eight participants prepared for a speech. Participants had higher heart rates and produced more armpit sweat in the fast stress condition, compared to baseline and the slow stress condition. Importantly, exposure to sweat from participants in the fast stress condition induced in receivers (N = 31) a simulacrum of the state of the sender, evidenced by the emergence of a fearful facial expression (facial electromyography) and vigilant behavior (i.e., faster classification of emotional facial expressions). PMID:25723720

Active eye-tracking for an adaptive optics scanning laser ophthalmoscope

PubMed Central

Sheehy, Christy K.; Tiruveedhula, Pavan; Sabesan, Ramkumar; Roorda, Austin

2015-01-01

We demonstrate a system that combines a tracking scanning laser ophthalmoscope (TSLO) and an adaptive optics scanning laser ophthalmoscope (AOSLO) system resulting in both optical (hardware) and digital (software) eye-tracking capabilities. The hybrid system employs the TSLO for active eye-tracking at a rate up to 960 Hz for real-time stabilization of the AOSLO system. AOSLO videos with active eye-tracking signals showed, at most, an amplitude of motion of 0.20 arcminutes for horizontal motion and 0.14 arcminutes for vertical motion. Subsequent real-time digital stabilization limited residual motion to an average of only 0.06 arcminutes (a 95% reduction). By correcting for high amplitude, low frequency drifts of the eye, the active TSLO eye-tracking system enabled the AOSLO system to capture high-resolution retinal images over a larger range of motion than previously possible with just the AOSLO imaging system alone. PMID:26203370

Eye movement-invariant representations in the human visual system.

PubMed

Nishimoto, Shinji; Huth, Alexander G; Bilenko, Natalia Y; Gallant, Jack L

2017-01-01

During natural vision, humans make frequent eye movements but perceive a stable visual world. It is therefore likely that the human visual system contains representations of the visual world that are invariant to eye movements. Here we present an experiment designed to identify visual areas that might contain eye-movement-invariant representations. We used functional MRI to record brain activity from four human subjects who watched natural movies. In one condition subjects were required to fixate steadily, and in the other they were allowed to freely make voluntary eye movements. The movies used in each condition were identical. We reasoned that the brain activity recorded in a visual area that is invariant to eye movement should be similar under fixation and free viewing conditions. In contrast, activity in a visual area that is sensitive to eye movement should differ between fixation and free viewing. We therefore measured the similarity of brain activity across repeated presentations of the same movie within the fixation condition, and separately between the fixation and free viewing conditions. The ratio of these measures was used to determine which brain areas are most likely to contain eye movement-invariant representations. We found that voxels located in early visual areas are strongly affected by eye movements, while voxels in ventral temporal areas are only weakly affected by eye movements. These results suggest that the ventral temporal visual areas contain a stable representation of the visual world that is invariant to eye movements made during natural vision.

Behavior of accessory abducens and abducens motoneurons during eye retraction and rotation in the alert cat.

PubMed

Delgado-Garcia, J M; Evinger, C; Escudero, M; Baker, R

1990-08-01

1. The activity of both accessory abducens (Acc Abd) and abducens (Abd) motoneurons (Mns) was recorded in the alert cat during eye retraction and rotational eye movements. Cats were fitted with two scleral coils, one measured rotational eye movements directly and the other retraction by distinguishing the translational component. 2. Acc Abd and Abd Mns were identified following antidromic activation from electrical stimulation of the ipsilateral VIth nerve. 3. In response to corneal air puffs, bursts of spikes were produced in all (n = 30) Acc Abd Mns. The burst began 7.2 +/- 1.2 (SD) ms after onset of the air puff and 8.9 +/- 1.9 ms before eye retraction. 4. Acc Abd Mns were silent throughout all types of rotational eye movements, and tonic activity was not observed during intervals without air-puff stimulation. 5. In contrast, all (n = 50) identified Abd Mns exhibited a burst and/or pause in activity preceding and during horizontal saccades as well as a tonic activity proportional to eye position. 6. Only 10% of Abd Mns fired a weak burst of spikes in response to air-puff stimulation. 7. We conclude that Acc Abd Mns are exclusively involved in eye retraction in the cat and that only a few Abd Mns have an eye-retraction signal added to their eye position and velocity signals. Thus any rotational eye-movement response described in retractor bulbi muscle must result from innervation by Mns located in the Abd and/or the oculomotor nuclei. 8. The organization of the prenuclear circuitry and species variation are discussed in view of the nictiating membrane extension response measured in associative learning.

Impact of Dry Eye Disease on Work Productivity, and Patients' Satisfaction With Over-the-Counter Dry Eye Treatments.

PubMed

Nichols, Kelly K; Bacharach, Jason; Holland, Edward; Kislan, Thomas; Shettle, Lee; Lunacsek, Orsolya; Lennert, Barb; Burk, Caroline; Patel, Vaishali

2016-06-01

To assess the effect of dry eye disease on work productivity and performance of non-work-related activities, and patients' satisfaction with over-the-counter (OTC) dry eye treatments. In this prospective, noninterventional, cross-sectional study, conducted at 10 U.S. optometry/ophthalmology practices, 158 symptomatic dry eye patients naïve to prescription medication underwent standard dry eye diagnostic tests and completed Work Productivity and Activity Impairment (WPAI) and Ocular Surface Disease Index (OSDI) questionnaires. Use of OTC dry eye medication, and satisfaction with OTC medication and symptom relief were also assessed. On average, dry eye resulted in loss of 0.36% of work time (∼5 minutes over 7 days) and ∼30% impairment of workplace performance (presenteeism), work productivity, and non-job-related activities. Presenteeism and productivity impairment scores showed significant correlation with OSDI total (r = 0.55) and symptom domain (r = 0.50) scores, but not with dry eye clinical signs. Activity impairment score showed stronger correlation with OSDI total (r = 0.61) and symptom domain (r = 0.53) scores than with clinical signs (r ≤ 0.20). Almost 75% of patients used OTC dry eye medication. Levels of patient satisfaction with OTC medication (64.2%) and symptom relief from OTC (37.3%) were unaffected by administration frequency (≥3 vs. ≤2 times daily). Dry eye causes negligible absenteeism, but markedly reduces workplace and non-job-related performances. Impairment of work performance is more closely linked to dry eye symptoms than to clinical signs. Patients' perceptions of OTC dry eye medication tend to be more positive than their perceptions of symptom relief.

Electrooculography-based continuous eye-writing recognition system for efficient assistive communication systems

PubMed Central

Shinozaki, Takahiro

2018-01-01

Human-computer interface systems whose input is based on eye movements can serve as a means of communication for patients with locked-in syndrome. Eye-writing is one such system; users can input characters by moving their eyes to follow the lines of the strokes corresponding to characters. Although this input method makes it easy for patients to get started because of their familiarity with handwriting, existing eye-writing systems suffer from slow input rates because they require a pause between input characters to simplify the automatic recognition process. In this paper, we propose a continuous eye-writing recognition system that achieves a rapid input rate because it accepts characters eye-written continuously, with no pauses. For recognition purposes, the proposed system first detects eye movements using electrooculography (EOG), and then a hidden Markov model (HMM) is applied to model the EOG signals and recognize the eye-written characters. Additionally, this paper investigates an EOG adaptation that uses a deep neural network (DNN)-based HMM. Experiments with six participants showed an average input speed of 27.9 character/min using Japanese Katakana as the input target characters. A Katakana character-recognition error rate of only 5.0% was achieved using 13.8 minutes of adaptation data. PMID:29425248

Sleep Impairment and Reduced Interneuron Excitability in a Mouse Model of Dravet Syndrome

PubMed Central

Kalume, Franck; Oakley, John C.; Westenbroek, Ruth E.; Gile, Jennifer; de la Iglesia, Horacio O.; Scheuer, Todd; Catterall, William A.

2015-01-01

Dravet Syndrome (DS) is caused by heterozygous loss-of-function mutations in voltage-gated sodium channel NaV1.1. Our genetic mouse model of DS recapitulates its severe seizures and premature death. Sleep disturbance is common in DS, but its mechanism is unknown. Electroencephalographic studies revealed abnormal sleep in DS mice, including reduced delta wave power, reduced sleep spindles, increased brief wakes, and numerous interictal spikes in Non-Rapid-Eye-Movement sleep. Theta power was reduced in Rapid-Eye-Movement sleep. Mice with NaV1.1 deleted specifically in forebrain interneurons exhibited similar sleep pathology to DS mice, but without changes in circadian rhythm. Sleep architecture depends on oscillatory activity in the thalamocortical network generated by excitatory neurons in the ventrobasal nucleus (VBN) of the thalamus and inhibitory GABAergic neurons in the reticular nucleus of the thalamus (RNT). Whole-cell NaV current was reduced in GABAergic RNT neurons but not in VBN neurons. Rebound firing of action potentials following hyperpolarization, the signature firing pattern of RNT neurons during sleep, was also reduced. These results demonstrate imbalance of excitatory vs. inhibitory neurons in this circuit. As predicted from this functional impairment, we found substantial deficit in homeostatic rebound of slow wave activity following sleep deprivation. Although sleep disorders in epilepsies have been attributed to anti-epileptic drugs, our results show that sleep disorder in DS mice arises from loss of NaV1.1 channels in forebrain GABAergic interneurons without drug treatment. Impairment of NaV currents and excitability of GABAergic RNT neurons are correlated with impaired sleep quality and homeostasis in these mice. PMID:25766678

Deficiency of FK506-binding protein (FKBP) 51 alters sleep architecture and recovery sleep responses to stress in mice.

PubMed

Albu, Stefana; Romanowski, Christoph P N; Letizia Curzi, M; Jakubcakova, Vladimira; Flachskamm, Cornelia; Gassen, Nils C; Hartmann, Jakob; Schmidt, Mathias V; Schmidt, Ulrike; Rein, Theo; Holsboer, Florian; Hausch, Felix; Paez-Pereda, Marcelo; Kimura, Mayumi

2014-04-01

FK506-binding protein 51 (FKBP51) is a co-chaperone of the glucocorticoid receptor, functionally linked to its activity via an ultra-short negative feedback loop. Thus, FKBP51 plays an important regulatory role in the hypothalamic-pituitary-adrenocortical (HPA) axis necessary for stress adaptation and recovery. Previous investigations illustrated that HPA functionality is influenced by polymorphisms in the gene encoding FKBP51, which are associated with both increased protein levels and depressive episodes. Because FKBP51 is a key molecule in stress responses, we hypothesized that its deletion impacts sleep. To study FKBP51-involved changes in sleep, polysomnograms of FKBP51 knockout (KO) mice and wild-type (WT) littermates were compared at baseline and in the recovery phase after 6-h sleep deprivation (SD) and 1-h restraint stress (RS). Using another set of animals, the 24-h profiles of hippocampal free corticosterone levels were also determined. The most dominant effect of FKBP51 deletion appeared as increased nocturnal wake, where the bout length was significantly extended while non-rapid eye movement sleep (NREMS) and rapid eye movement sleep were rather suppressed. After both SD and RS, FKBP51KO mice exhibited less recovery or rebound sleep than WTs, although slow-wave activity during NREMS was higher in KOs, particularly after SD. Sleep compositions of KOs were nearly opposite to sleep profiles observed in human depression. This might result from lower levels of free corticosterone in FKBP51KO mice, confirming reduced HPA reactivity. The results indicate that an FKBP51 deletion yields a pro-resilience sleep phenotype. FKBP51 could therefore be a therapeutic target for stress-induced mood and sleep disorders. © 2013 European Sleep Research Society.

Wake and Sleep EEG in Patients With Huntington Disease: An eLORETA Study and Review of the Literature.

PubMed

Piano, Carla; Mazzucchi, Edoardo; Bentivoglio, Anna Rita; Losurdo, Anna; Calandra Buonaura, Giovanna; Imperatori, Claudio; Cortelli, Pietro; Della Marca, Giacomo

2017-01-01

The aim of the study was to evaluate the EEG modifications in patients with Huntington disease (HD) compared with controls, by means of the exact LOw REsolution Tomography (eLORETA) software. We evaluated EEG changes during wake, non-rapid eye movement (NREM) and rapid eye movement (REM) sleep. Moreover, we reviewed the literature concerning EEG modifications in HD. Twenty-three consecutive adult patients affected by HD were enrolled, 14 women and 9 men, mean age was 57.0 ± 12.4 years. Control subjects were healthy volunteers (mean age 58.2 ± 14.6 years). EEG and polygraphic recordings were performed during wake (before sleep) and during sleep. Sources of EEG activities were determined using the eLORETA software. In wake EEG, significant differences between patients and controls were detected in the delta frequency band (threshold T = ±4.606; P < .01) in the Brodmann areas (BAs) 3, 4, and 6 bilaterally. In NREM sleep, HD patients showed increased alpha power (T = ±4.516; P < .01) in BAs 4 and 6 bilaterally; decreased theta power (T = ±4.516; P < .01) in the BAs 23, 29, and 30; and decreased beta power (T = ±4.516; P < .01) in the left BA 30. During REM, HD patients presented decreased theta and alpha power (threshold T = ±4.640; P < .01) in the BAs 23, 29, 30, and 31 bilaterally. In conclusion, EEG data suggest a motor cortex dysfunction during wake and sleep in HD patients, which correlates with the clinical and polysomnographic evidence of increased motor activity during wake and NREM, and nearly absent motor abnormalities in REM. © EEG and Clinical Neuroscience Society (ECNS) 2016.

In utero exposure to valproic acid changes sleep in juvenile rats: a model for sleep disturbances in autism.

PubMed

Cusmano, Danielle M; Mong, Jessica A

2014-09-01

To determine whether sleep disturbances are found in the valproic acid model of autism spectrum disorders (ASD). Comparative study for sleep behavior, sleep architecture, electroencephalogram (EEG) spectral analysis, and glutamic acid decarboxylase (GAD) 65/67 protein expression in juvenile rats exposed to valproic acid (VPA), sodium salt, or saline in utero. N/A. Juvenile (postnatal day 32) male and female Sprague-Dawley rats. In utero exposure to either saline or 400 mg/kg VPA administered intraperitoneally to the dams on gestational day 12.5. On postnatal days 22-24, all rats were implanted with transmitters to record EEG and electromyogram (EMG) activity. During the light phase, when nocturnal animals are typically quiescent, the VPA-exposed animals spent significantly more time in wake (∼35 min) and significantly less time in non-rapid eye movement (NREM) sleep (∼26 min) compared to the saline controls. Furthermore, spectral analysis of the EEG revelled that VPA-exposed animals exhibited increased high-frequency activity during wake and rapid eye movement (REM) sleep and reduced theta power across all vigilance states. Interestingly, the gamma-aminobutyric acid (GABA)-ergic system, which modulates the induction and maintenance of sleep states, was also disrupted, with reduced levels of both GAD 65 and GAD67 in the cortical tissue of VPA-exposed animals compared to saline controls. To date, the current animal models of ASD have been underutilized in the investigation of associated sleep disturbances. The VPA animal model recapitulates aspects of sleep disruptions reported clinically, providing a tool to investigate cellular and molecular dysregulation contributing to sleep disruptions in ASD. © 2014 Associated Professional Sleep Societies, LLC.

A Biphasic Change of Regional Blood Volume in the Frontal Cortex during Non-Rapid Eye Movement Sleep: A Near-Infrared Spectroscopy Study.

PubMed

Zhang, Zhongxing; Khatami, Ramin

2015-08-01

Current knowledge on hemodynamics in sleep is limited because available techniques do not allow continuous recordings and mainly focus on cerebral blood flow while neglecting other important parameters, such as blood volume (BV) and vasomotor activity. Observational study. Continuous measures of hemodynamics over the left forehead and biceps were performed using near-infrared spectroscopy (NIRS) during nocturnal polysomnography in 16 healthy participants in sleep laboratory. Temporal dynamics and mean values of cerebral and muscular oxygenated hemoglobin (HbO2), deoxygenated hemoglobin (HHb), and BV during different sleep stages were compared. A biphasic change of cerebral BV was observed which contrasted a monotonic increase of muscular BV during non-rapid eye movement sleep. A significant decrement in cerebral HbO2 and BV accompanied by an increase of HHb was recorded at sleep onset (Phase I). Prior to slow wave sleep (SWS) HbO2 and BV turned to increase whereas HHb began to decrease in subsequent Phase II suggested increased brain perfusion during SWS. The cerebral HbO2 slope correlated to BV slope in Phase I and II, but it only correlated to HHb slope in Phase II. The occurrence time of inflection points correlated to SWS latencies. Initial decrease of brain perfusion with decreased blood volume (BV) and oxygenated hemoglobin (HbO2) together with increasing muscular BV fit thermoregulation process at sleep onset. The uncorrelated and correlated slopes of HbO2 and deoxygenated hemoglobin indicate different mechanisms underlying the biphasic hemodynamic process in light sleep and slow wave sleep (SWS). In SWS, changes in vasomotor activity (i.e., increased vasodilatation) may mediate increasing cerebral and muscular BV. © 2015 Associated Professional Sleep Societies, LLC.

Morin hydrate mitigates rapid eye movement sleep deprivation-induced neurobehavioural impairments and loss of viable neurons in the hippocampus of mice.

PubMed

Olonode, Elizabeth T; Aderibigbe, Adegbuyi O; Adeoluwa, Olusegun A; Eduviere, Anthony T; Ben-Azu, Benneth

2017-12-25

Rapid eye movement sleep deprivation distorts the body's homeostasis and results in oxidative breakdown which may be responsible for a variety of neurological disorders. Some naturally occurring compounds of plant origin with antioxidant and neuroprotective properties are known to attenuate the detrimental effects of REM sleep deprivation. Morin hydrate, a flavonoid from Mulberry has demonstrated antioxidant and neuroprotective activities but its effect in sleep disturbed mice is unknown. The study was designed to explore the neuroprotective effect of Morin hydrate on 48 h. REM sleep deprivation-induced behavioural impairments and neuronal damage in mice. Mice were allotted into six treatment groups (n = 6): groups 1 and 2 received vehicle (10 ml/kg normal saline), groups 3-5 received Morin hydrate (5, 10, 20 mg/kg i.p) while group 6 received ginseng (25 mg/kg) which served as the reference drug. Treatment was performed daily for 5 days and animals were sleep-deprived on the last 48 h. Various behavioural tests (Elevated plus maze, Y-maze, locomotor activity) followed by oxidative parameters (malondialdehyde, nitric oxide, reduced glutathione) and histolopathological changes in the Cornu ammonis 1 (CA1) region of the hippocampus were assessed. Data were analysed using ANOVA at α 0.05 . Morin hydrate (5, 10, 20 mg/kg) significantly enhanced memory performance, improves anxiolytic-like behaviour, reverses hyperlocomotion, restored depleted reduced glutathione, attenuated raised malondialdehyde and nitric oxide levels as compared to control animals and protects against loss of hippocampal neurons. Results of this present study suggest that Morin hydrate possess neuroprotective effects against sleep deprivation-induced behavioural impairments, oxidative stress and neuronal damage. Copyright © 2017 Elsevier B.V. All rights reserved.

Neocortical 40 Hz oscillations during carbachol-induced rapid eye movement sleep and cataplexy.

PubMed

Torterolo, Pablo; Castro-Zaballa, Santiago; Cavelli, Matías; Chase, Michael H; Falconi, Atilio

2016-02-01

Higher cognitive functions require the integration and coordination of large populations of neurons in cortical and subcortical regions. Oscillations in the gamma band (30-45 Hz) of the electroencephalogram (EEG) have been involved in these cognitive functions. In previous studies, we analysed the extent of functional connectivity between cortical areas employing the 'mean squared coherence' analysis of the EEG gamma band. We demonstrated that gamma coherence is maximal during alert wakefulness and is almost absent during rapid eye movement (REM) sleep. The nucleus pontis oralis (NPO) is critical for REM sleep generation. The NPO is considered to exert executive control over the initiation and maintenance of REM sleep. In the cat, depending on the previous state of the animal, a single microinjection of carbachol (a cholinergic agonist) into the NPO can produce either REM sleep [REM sleep induced by carbachol (REMc)] or a waking state with muscle atonia, i.e. cataplexy [cataplexy induced by carbachol (CA)]. In the present study, in cats that were implanted with electrodes in different cortical areas to record polysomnographic activity, we compared the degree of gamma (30-45 Hz) coherence during REMc, CA and naturally-occurring behavioural states. Gamma coherence was maximal during CA and alert wakefulness. In contrast, gamma coherence was almost absent during REMc as in naturally-occurring REM sleep. We conclude that, in spite of the presence of somatic muscle paralysis, there are remarkable differences in cortical activity between REMc and CA, which confirm that EEG gamma (≈40 Hz) coherence is a trait that differentiates wakefulness from REM sleep. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Rapid shelf-wide cooling response of a stratified coastal ocean to hurricanes.

PubMed

Seroka, Greg; Miles, Travis; Xu, Yi; Kohut, Josh; Schofield, Oscar; Glenn, Scott

2017-06-01

Large uncertainty in the predicted intensity of tropical cyclones (TCs) persists compared to the steadily improving skill in the predicted TC tracks. This intensity uncertainty has its most significant implications in the coastal zone, where TC impacts to populated shorelines are greatest. Recent studies have demonstrated that rapid ahead-of-eye-center cooling of a stratified coastal ocean can have a significant impact on hurricane intensity forecasts. Using observation-validated, high-resolution ocean modeling, the stratified coastal ocean cooling processes observed in two U.S. Mid-Atlantic hurricanes were investigated: Hurricane Irene (2011)-with an inshore Mid-Atlantic Bight (MAB) track during the late summer stratified coastal ocean season-and Tropical Storm Barry (2007)-with an offshore track during early summer. For both storms, the critical ahead-of-eye-center depth-averaged force balance across the entire MAB shelf included an onshore wind stress balanced by an offshore pressure gradient. This resulted in onshore surface currents opposing offshore bottom currents that enhanced surface to bottom current shear and turbulent mixing across the thermocline, resulting in the rapid cooling of the surface layer ahead-of-eye-center. Because the same baroclinic and mixing processes occurred for two storms on opposite ends of the track and seasonal stratification envelope, the response appears robust. It will be critical to forecast these processes and their implications for a wide range of future storms using realistic 3-D coupled atmosphere-ocean models to lower the uncertainty in predictions of TC intensities and impacts and enable coastal populations to better respond to increasing rapid intensification threats in an era of rising sea levels.

Prenatal Diagnosis of a Case of Norrie Disease with Late Development of Bilateral Ocular Malformation.

PubMed

Wu, Li Hong; Chen, Li-Hong; Xie, Hongning; Xie, Ying-Jun

2017-06-01

We report a case of Norrie disease, diagnosed by prenatal ultrasound, confirmed by Sanger sequencing of the DNP gene from the aborted fetal cord blood and histologically. Prenatal ultrasound revealed no abnormality in either eye at 22 +1 and 31 +4 gestational weeks, but at 36 +5 gestational weeks both eyes had massive vitreous cavity opacities with complete retinal detachment. Norrie disease was initially suspected because of an older male sibling with the disease. To our knowledge, prenatal ultrasound diagnosis of Norrie disease has been previously described only one case in 1993 in a 34-week-old fetus. The normal eye development until after 31 + 4 gestational weeks provides insight into the first manifestation and then the rapid progression of the eye disease.

The impact of diurnal sleep on the consolidation of a complex gross motor adaptation task.

PubMed

Hoedlmoser, Kerstin; Birklbauer, Juergen; Schabus, Manuel; Eibenberger, Patrick; Rigler, Sandra; Mueller, Erich

2015-02-01

Diurnal sleep effects on consolidation of a complex, ecological valid gross motor adaptation task were examined using a bicycle with an inverse steering device. We tested 24 male subjects aged between 20 and 29 years using a between-subjects design. Participants were trained to adapt to the inverse steering bicycle during 45 min. Performance was tested before (TEST1) and after (TEST2) training, as well as after a 2 h retention interval (TEST3). During retention, participants either slept or remained awake. To assess gross motor performance, subjects had to ride the inverse steering bicycle 3 × 30 m straight-line and 3 × 30 m through a slalom. Beyond riding time, we sophisticatedly measured performance accuracy (standard deviation of steering angle) in both conditions using a rotatory potentiometer. A significant decrease of accuracy during straight-line riding after nap and wakefulness was shown. Accuracy during slalom riding remained stable after wakefulness but was reduced after sleep. We found that the duration of rapid eye movement sleep as well as sleep spindle activity are negatively related with gross motor performance changes over sleep. Together these findings suggest that the consolidation of adaptation to a new steering device does not benefit from a 2 h midday nap. We speculate that in case of strongly overlearned motor patterns such as normal cycling, diurnal sleep spindles and rapid eye movement sleep might even help to protect everyday needed skills, and to rapidly forget newly acquired, interfering and irrelevant material. © 2014 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.

Effects of Rapid Weight Loss on Balance and Reaction Time in Elite Judo Athletes.

PubMed

Morales, Jose; Ubasart, Carla; Solana-Tramunt, Mónica; González, Luis-Millán; Fukuda, David; Franchini, Emerson

2018-05-29

Balance, reaction time, and strength are key factors affecting judo performance. While ample research exists examining potential strength changes caused by weight loss prior to competition, changes in balance and reaction time, have been overlooked. The objective of this study was to examine the effects of rapid and progressive weight loss (RWL and PWL) on balance, reaction time, and strength in a group of elite judo athletes. 38 female and male judo athletes (age = 20.6 ± 2.6 years) completed balance, reaction time, and strength assessments one week prior to an official weigh-in (pre-test) and immediately after the weigh-in (post-test). The judo athletes were divided into three groups, one control group who maintained regular training and eating habits, one experimental group who engaged in PWL (<3% reductions in body mass) and a second experimental group who used RWL techniques (>3% reductions in body mass). RWL group showed significant decreases (p<0.05) in balance performance (Ellipse area: 4.83±0.87 vs. 6.31±1.39 mm 2 with eyes closed; Mean Mediolateral Velocity: 2.07±0.2 vs. 2.52±0.45 mms -1 with eyes closed; Mean Anteroposterior Velocity: 2.25±0.20 vs. 2.51±0.32 mms -1 with eyes open and 2.44±0.26 vs. 3.06±0.56 mms -1 with eyes closed) and reaction time (0.38±0.04 vs. 0.42±0.06 seconds) with no changes in strength from pre- to post-testing. The judo athletes in the progressive weight loss and control groups maintained performance in all variables. These findings demonstrate negative effects on perceptual motor skill performance in judo athletes engaging in rapid weight loss strategies prior to competition.

Fight or flight? Dream content during sleepwalking/sleep terrors vs. rapid eye movement sleep behavior disorder.

PubMed

Uguccioni, Ginevra; Golmard, Jean-Louis; de Fontréaux, Alix Noël; Leu-Semenescu, Smaranda; Brion, Agnès; Arnulf, Isabelle

2013-05-01

Dreams enacted during sleepwalking or sleep terrors (SW/ST) may differ from those enacted during rapid eye movement sleep behavior disorder (RBD). Subjects completed aggression, depression, and anxiety questionnaires. The mentations associated with SW/ST and RBD behaviors were collected over their lifetime and on the morning after video polysomnography (PSG). The reports were analyzed for complexity, length, content, setting, bizarreness, and threat. Ninety-one percent of 32 subjects with SW/ST and 87.5% of 24 subjects with RBD remembered an enacted dream (121 dreams in a lifetime and 41 dreams recalled on the morning). These dreams were more complex and less bizarre, with a higher level of aggression in the RBD than in SW/ST subjects. In contrast, we found low aggression, anxiety, and depression scores during the daytime in both groups. As many as 70% of enacted dreams in SW/ST and 60% in RBD involved a threat, but there were more misfortunes and disasters in the SW/ST dreams and more human and animal aggressions in the RBD dreams. The response to these threats differed, as the sleepwalkers mostly fled from a disaster (and 25% fought back when attacked), while 75% of RBD subjects counterattacked when assaulted. The dreams setting included their bedrooms in 42% SW/ST dreams, though this finding was exceptional in the RBD dreams. Different threat simulations and modes of defense seem to play a role during dream-enacted behaviors (e.g., fleeing a disaster during SW/ST, counterattacking a human or animal assault during RBD), paralleling and exacerbating the differences observed between normal dreaming in nonrapid eye movement (NREM) vs rapid eye movement (REM) sleep. Copyright © 2013 Elsevier B.V. All rights reserved.

Ethical and Pedagogical Issues in the Use of Simulation Activities in the Classroom: Evaluating the "Blue Eyes-Brown Eyes" Prejudice Simulation.

ERIC Educational Resources Information Center

Byrnes, Deborah A.; Kiger, Gary

The effectiveness of a well-known prejudice-reduction simulation activity, "Blue Eyes-Brown Eyes," was assessed as a tool for changing the attitudes of nonblack teacher education students toward blacks. The subjects were 164 students enrolled in eight sections of an introductory elementary education course at a state university. Three…

Active eye-tracking improves LASIK results.

PubMed

Lee, Yuan-Chieh

2007-06-01

To study the advantage of active eye-tracking for photorefractive surgery. In a prospective, double-masked study, LASIK for myopia and myopic astigmatism was performed in 50 patients using the ALLEGRETTO WAVE version 1007. All patients received LASIK with full comprehension of the importance of fixation during the procedure. All surgical procedures were performed by a single surgeon. The eye-tracker was turned off in one group (n = 25) and kept on in another group (n = 25). Preoperatively and 3 months postoperatively, patients underwent a standard ophthalmic examination, which included comeal topography. In the patients treated with the eye-tracker off, all had uncorrected visual acuity (UCVA) of > or = 20/40 and 64% had > or = 20/20. Compared with the patients treated with the eye-tracker on, they had higher residual cylindrical astigmatism (P < .05). Those treated with the eye-tracker on achieved better UCVA and best spectacle-corrected visual acuity (P < .05). Spherical error and potential visual acuity (TMS-II) were not significantly different between the groups. The flying-spot system can achieve a fair result without active eye-tracking, but active eye-tracking helps improve the visual outcome and reduces postoperative cylindrical astigmatism.

Early Detection Rapid Response Program Targets New Noxious Weed Species in Washington State

ERIC Educational Resources Information Center

Andreas, Jennifer E.; Halpern, Alison D.; DesCamp, Wendy C.; Miller, Timothy W.

2015-01-01

Early detection, rapid response is a critical component of invasive plant management. It can be challenging, however, to detect new invaders before they become established if landowners cannot identify species of concern. In order to increase awareness, eye-catching postcards were developed in Washington State as part of a noxious weed educational…

Excessive ingestion of long-chain polyunsaturated fatty acids during developmental stage causes strain- and sex-dependent eye abnormalities in mice.

PubMed

Maekawa, Motoko; Iwayama, Yoshimi; Watanabe, Akiko; Nozaki, Yayoi; Ohnishi, Tetsuo; Ohba, Hisako; Toyoshima, Manabu; Hamazaki, Kei; Osumi, Noriko; Aruga, Jun; Yoshikawa, Takeo

2010-11-12

The eyes are rich in long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic acid [ARA; 20:4 (n-6)] and docosahexaenoic acid [DHA; 22:6 (n-3)]. Despite their abundance in the eyes, ARA and DHA cannot be sufficiently synthesized de novo in mammals. During gestation, eye development is exceptionally rapid, and substantial amounts of LC-PUFAs are needed to ensure proper eye development. Here, we studied the influences of dietary LC-PUFAs in dams (C57BL/6 and C3H/He) on the eye morphogenesis and organogenesis of their pups. Intriguingly, fetuses and newborn mice from C57BL/6 dams fed an LC-PUFA (particularly ARA)-enriched diet displayed a much higher incidence of eye abnormalities such as microphthalmia (small eye) and corneal opacity than those from dams fed an LC-PUFA-poor diet. The effects of LC-PUFAs on eye anomalies were evident only in the female pups of C57BL/6 inbred mice, not in those of C3H/He mice or male C57BL/6 mice. These results demonstrate a gene-by-environment (GxE) interaction in eye development in mice. Furthermore, our molecular analysis suggested the potential roles of Pitx3 and Pax6 in the above interaction involving ARA. Copyright © 2010 Elsevier Inc. All rights reserved.

Dynamic eye colour as an honest signal of aggression.

PubMed

Heathcote, Robert J P; Darden, Safi K; Troscianko, Jolyon; Lawson, Michael R M; Brown, Antony M; Laker, Philippa R; Naisbett-Jones, Lewis C; MacGregor, Hannah E A; Ramnarine, Indar; Croft, Darren P

2018-06-04

Animal eyes are some of the most widely recognisable structures in nature. Due to their salience to predators and prey, most research has focused on how animals hide or camouflage their eyes [1]. However, across all vertebrate Classes, many species actually express brightly coloured or conspicuous eyes, suggesting they may have also evolved a signalling function. Nevertheless, perhaps due to the difficulty with experimentally manipulating eye appearance, very few species beyond humans [2] have been experimentally shown to use eyes as signals [3]. Using staged behavioural trials we show that Trinidadian guppies (Poecilia reticulata), which can rapidly change their iris colour, predominantly express conspicuous eye colouration when performing aggressive behaviours towards smaller conspecifics. Furthermore, using a novel, visually realistic robotic system to create a mismatch between signal and relative competitive ability, we show that eye colour is used to honestly signal aggressive motivation. Specifically, robotic 'cheats' (that is, smaller, less-competitive robotic fish that display aggressive eye colouration when defending a food patch) attracted greater food competition from larger real fish. Our study suggests that eye colour may be an under-appreciated aspect of signalling in animals, shows the utility of our biomimetic robotic system for investigating animal behaviour, and provides experimental evidence that socially mediated costs towards low-quality individuals may maintain the honesty of dynamic colour signals. Copyright © 2018 Elsevier Ltd. All rights reserved.

Dynamic modulation of ocular orientation during visually guided saccades and smooth-pursuit eye movements

NASA Technical Reports Server (NTRS)

Hess, Bernhard J M.; Angelaki, Dora E.

2003-01-01

Rotational disturbances of the head about an off-vertical yaw axis induce a complex vestibuloocular reflex pattern that reflects the brain's estimate of head angular velocity as well as its estimate of instantaneous head orientation (at a reduced scale) in space coordinates. We show that semicircular canal and otolith inputs modulate torsional and, to a certain extent, also vertical ocular orientation of visually guided saccades and smooth-pursuit eye movements in a similar manner as during off-vertical axis rotations in complete darkness. It is suggested that this graviceptive control of eye orientation facilitates rapid visual spatial orientation during motion.

Effects of monocular viewing and eye dominance on spatial attention.

PubMed

Roth, Heidi L; Lora, Andrea N; Heilman, Kenneth M

2002-09-01

Observations in primates and patients with unilateral spatial neglect have suggested that patching of the eye ipsilateral to the injury and contralateral to the neglected space can sometimes improve attention to the neglected space. Investigators have generally attributed the effects of monocular eye patching to activation of subcortical centers that interact with cortical attentional systems. Eye patching is thought to produce preferential activation of attentional systems contralateral to the viewing eye. In this study we examined the effect of monocular eye patching on attentional biases in normal subjects. When normal subjects bisect vertical (radial) lines using both eyes, they demonstrate a far attentional bias, misbisecting lines away from their body. In a monocular viewing experiment, we found that the majority of subjects, who were right eye dominant, had relatively nearer bisections and a diminished far bias when they used their right eye (left eye covered) compared with when they used their left eye (right eye covered). The smaller group of subjects who were left eye dominant had relatively nearer bisections and a diminished far bias when they used their left eye compared with when they used their right eye. In the hemispatial placement experiment, we directly manipulated hemispheric engagement by having subjects perform the same task in right and left hemispace. We found that right eye dominant subjects had a diminished far bias in right hemispace relative to left hemispace. Left eye dominant subjects showed the opposite pattern and had a diminished far bias in left hemispace. For both groups, spatial presentation affected performance more for the non-dominant eye. The results suggest that monocular viewing is associated with preferential activation of attentional systems in the contralateral hemisphere, and that the right hemisphere (at least in right eye dominant subjects) is biased towards far space. Finally, the results suggest that the poorly understood phenomenon of eye dominance may be related to hemispheric specialization for visual attention.

Rapid micromotor-based naked-eye immunoassay.

PubMed

de Ávila, Berta Esteban-Fernández; Zhao, Mingjiao; Campuzano, Susana; Ricci, Francesco; Pingarrón, José M; Mascini, Marcello; Wang, Joseph

2017-05-15

A dynamic micromotor-based immunoassay, exemplified by cortisol detection, based on the use of tubular micromotors functionalized with a specific antibody is described. The use of antibody-functionalized micromotors offers huge acceleration of both direct and competitive cortisol immunoassays, along with greatly enhanced sensitivity of direct and competitive immunoassays. The dramatically improved speed and sensitivity reflect the greatly increased likelihood of antibody-cortisol contacts and fluid mixing associated with the dynamic movement of these microtube motors and corresponding bubble generation that lead to a highly efficient and rapid recognition process. Rapid naked-eye detection of cortisol in the sample is achieved in connection to use of horseradish peroxidase (HRP) tag and TMB/H 2 O 2 system. Key parameters of the competitive immunoassay (e.g., incubation time and reaction volume) were optimized. This fast visual micromotor-based sensing approach enables "on the move" specific detection of the target cortisol down to 0.1μgmL -1 in just 2min, using ultrasmall (50µL) sample volumes. Copyright © 2017 Elsevier B.V. All rights reserved.

NASA Sees Cyclone Chapala Approaching Landfall in Yemen

NASA Image and Video Library

2017-12-08

On Nov. 2, 2015 at 09:40 UTC (4:40 p.m. EDT) the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite captured an image of Tropical Cyclone Chapala as the eye of the storm was approaching the Yemen coast. Chapala maintained an eye, although it appeared cloud-covered. Animated multispectral satellite imagery shows the system has maintained a 15-nautical-mile-wide eye and structure. The image was created by the MODIS Rapid Response Team at NASA's Goddard Space Flight Center, Greenbelt, Maryland. Chapala weakened from category four intensity a couple days ago while maintaining a course that steers it toward Yemen. Credit: NASA Goddard MODIS Rapid Response Team Read more: www.nasa.gov/f…/goddard/chapala-northern-indian-ocean NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

Phosphorylation of CaMKII in the rat dorsal raphe nucleus plays an important role in sleep-wake regulation.

PubMed

Cui, Su-Ying; Li, Sheng-Jie; Cui, Xiang-Yu; Zhang, Xue-Qiong; Yu, Bin; Sheng, Zhao-Fu; Huang, Yuan-Li; Cao, Qing; Xu, Ya-Ping; Lin, Zhi-Ge; Yang, Guang; Song, Jin-Zhi; Ding, Hui; Wang, Zi-Jun; Zhang, Yong-He

2016-02-01

The Ca(2+) modulation in the dorsal raphe nucleus (DRN) plays an important role in sleep-wake regulation. Calmodulin-dependent kinase II (CaMKII) is an important signal-transducing molecule that is activated by Ca(2+) . This study investigated the effects of intracellular Ca(2+) /CaMKII signaling in the DRN on sleep-wake states in rats. Maximum and minimum CaMKII phosphorylation was detected at Zeitgeber time 21 (ZT 21; wakefulness state) and ZT 3 (sleep state), respectively, across the light-dark rhythm in the DRN in rats. Six-hour sleep deprivation significantly reduced CaMKII phosphorylation in the DRN. Microinjection of the CAMKII activation inhibitor KN-93 (5 or 10 nmol) into the DRN suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REM sleep (NREMS). Application of a high dose of KN-93 (10 nmol) increased slow-wave sleep (SWS) time, SWS bouts, the mean duration of SWS, the percentage of SWS relative to total sleep, and delta power density during NREMS. Microinjection of CaCl2 (50 nmol) in the DRN increased CaMKII phosphorylation and decreased NREMS, SWS, and REMS. KN-93 abolished the inhibitory effects of CaCl2 on NREMS, SWS, and REMS. These data indicate a novel wake-promoting and sleep-suppressing role for the Ca(2+) /CaMKII signaling pathway in DRN neurons. We propose that the intracellular Ca(2+) /CaMKII signaling in the dorsal raphe nucleus (DRN) plays wake-promoting and sleep-suppressing role in rats. Intra-DRN application of KN-93 (CaMKII activation inhibitor) suppressed wakefulness and enhanced rapid-eye-movement sleep (REMS) and non-REMS (NREMS). Intra-DRN application of CaCl2 attenuated REMS and NREMS. We think these findings should provide a novel cellular and molecular mechanism of sleep-wake regulation. © 2015 International Society for Neurochemistry.

A Scientist at Work.

ERIC Educational Resources Information Center

Morrison, Adrian R.

1999-01-01

Relates personal experiences conducting scientific research on the brain mechanisms of rapid eye movement (REM) sleep. Argues that solutions to scientific questions can come from strange sources. Contains 13 references. (WRM)

Eye-closure-triggered paroxysmal activity and cognitive impairment: a case report.

PubMed

Termine, Cristiano; Rubboli, Guido; Veggiotti, Pierangelo

2006-01-01

To study the neuropsychological status of an epileptic patient presenting with epileptic activity triggered by eye closure in a 14-year follow-up period. The patient was studied at 12 and 26 years of age; during this period he underwent periodical clinical evaluations and EEG investigations; brain magnetic resonance imaging (MRI) was performed at 12 years of age. A neuropsychological assessment was carried out both at 12 years of age (T0) and at 26 years of age. At T0 and T1, neuropsychological tests (digits and words span, graphoestesia, reactions time to auditory stimuli, sentences repetition, words repetition, digital gnosis, backward counting [i.e.,100-0]) were performed during video-EEG monitoring either with eyes closed or with eyes open, to evaluate possible transitory effects related to ongoing epileptic activity. Moreover, at T0 the patient underwent Wechsler Intelligence Scale for Children-Revised, and at T1 to Wechsler Adult Intelligence Scale-Revised. EEG recordings showed continuous epileptic activity triggered by eye closure, disappearing only with eyes opening, both at T0 and T1 (in this latter case, anteriorly predominant). The results of neuropsychological assessment during eyes closed as compared to performances with eyes open did not show significant differences, at T0 as well as at T1. Wechsler Intelligence scales showed a deterioration of performances at T1 with respect to T0; in addition, at T1, attention and short-term memory abnormalities, impairment in facial recognition and block design, and defective results in Continuous Performance Test and Wisconsin Card Sorting Test were observed. Lack of differences between the results of neuropsychological tests performed with eyes closed as compared to the eyes open condition suggests that in our patient epileptic activity did not cause transitory cognitive abnormalities. Deterioration of Wechsler Intelligence Scales in the follow-up period might be interpreted as the result of a disruption of cognitive processes possibly related to the persistence of a continuous epileptic activity during eye closure over the years. We speculate whether a dysfunction in posterior cortical areas involved in visual processing might be related to the impairment in face recognition and block design tests as well to eye closure sensitivity.

Acidic mammalian chitinase in dry eye conditions.

PubMed

Musumeci, Maria; Aragona, Pasquale; Bellin, Milena; Maugeri, Francesco; Rania, Laura; Bucolo, Claudio; Musumeci, Salvatore

2009-07-01

An acidic mammalian chitinase (AMCase) seems to be implicated in allergic asthma and allergic ocular pathologies. The aim of this work was to investigate the role of AMCase during Sjögren's Syndrome (SS) and Meibomian Gland Dysfunction (MGD) dry eye diseases. Six patients with MGD dry eye (20-58 years, median 40) and six patients with dry eye associated to SS (32-60 years, median 47) were enrolled in this study. AMCase activity was measured in tears and AMCase mRNA expression was evaluated by real-time polymerase chain reaction from RNA extracted from epithelial cells of the conjunctiva. Six healthy adult subjects of the same age (34-44 years, median 39) were also studied as the control group. AMCase activity was significantly increased in patients affected by MGD dry eye (18.54 +/- 1.5 nmol/ml/h) and SS dry eye (8.94 +/- 1.0 nmol/ml/h) respectively, compared to healthy controls (1.6 +/- 0.2 nmol/ml/h). AMCase activity was higher in the tears of subjects with MGD dry eye (P < 0.001). AMCase mRNA was detected in conjunctival epithelial cells and the expression was significantly higher in MGD dry eye than SS dry eye. A significant correlation between AMCase activity in the tears and mRNA in conjunctival epithelial cells was found. AMCase may be an important marker in the pathogenesis of dry eye, suggesting the potential role of AMCase as a therapeutic target in these frequent pathologies.

An ocular biomechanic model for dynamic simulation of different eye movements.

PubMed

Iskander, J; Hossny, M; Nahavandi, S; Del Porto, L

2018-04-11

Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biomechanic ocular models that are easily integrated into the available musculoskeletal models. The model was previously used to simulate eye-head coordination. The models are used to simulate and analyse eye movements. The proposed models are based on physiological and kinematic properties of the human eye. They incorporate an eye-globe, orbital suspension tissues and six muscles with their connective tissues (pulleys). Pulleys were incorporated in rectus and inferior oblique muscles. The two proposed models are the passive pulleys and the active pulleys models. Dynamic simulations of different eye movements, including fixation, saccade and smooth pursuit, are performed to validate both models. The resultant force-length curves of the models were similar to the experimental data. The simulation results show that the proposed models are suitable to generate eye movement simulations with results comparable to other musculoskeletal models. The maximum kinematic root mean square error (RMSE) is 5.68° and 4.35° for the passive and active pulley models, respectively. The analysis of the muscle forces showed realistic muscle activation with increased muscle synergy in the active pulley model. Copyright © 2018 Elsevier Ltd. All rights reserved.

Binocular Therapy for Childhood Amblyopia Improves Vision Without Breaking Interocular Suppression.

PubMed

Bossi, Manuela; Tailor, Vijay K; Anderson, Elaine J; Bex, Peter J; Greenwood, John A; Dahlmann-Noor, Annegret; Dakin, Steven C

2017-06-01

Amblyopia is a common developmental visual impairment characterized by a substantial difference in acuity between the two eyes. Current monocular treatments, which promote use of the affected eye by occluding or blurring the fellow eye, improve acuity, but are hindered by poor compliance. Recently developed binocular treatments can produce rapid gains in visual function, thought to be as a result of reduced interocular suppression. We set out to develop an effective home-based binocular treatment system for amblyopia that would engage high levels of compliance but that would also allow us to assess the role of suppression in children's response to binocular treatment. Balanced binocular viewing therapy (BBV) involves daily viewing of dichoptic movies (with "visibility" matched across the two eyes) and gameplay (to monitor compliance and suppression). Twenty-two children (3-11 years) with anisometropic (n = 7; group 1) and strabismic or combined mechanism amblyopia (group 2; n = 6 and 9, respectively) completed the study. Groups 1 and 2 were treated for a maximum of 8 or 24 weeks, respectively. The treatment elicited high levels of compliance (on average, 89.4% ± 24.2% of daily dose in 68.23% ± 12.2% of days on treatment) and led to a mean improvement in acuity of 0.27 logMAR (SD 0.22) for the amblyopic eye. Importantly, acuity gains were not correlated with a reduction in suppression. BBV is a binocular treatment for amblyopia that can be self-administered at home (with remote monitoring), producing rapid and substantial benefits that cannot be solely mediated by a reduction in interocular suppression.

Eye movement analysis for activity recognition using electrooculography.

PubMed

Bulling, Andreas; Ward, Jamie A; Gellersen, Hans; Tröster, Gerhard

2011-04-01

In this work, we investigate eye movement analysis as a new sensing modality for activity recognition. Eye movement data were recorded using an electrooculography (EOG) system. We first describe and evaluate algorithms for detecting three eye movement characteristics from EOG signals-saccades, fixations, and blinks-and propose a method for assessing repetitive patterns of eye movements. We then devise 90 different features based on these characteristics and select a subset of them using minimum redundancy maximum relevance (mRMR) feature selection. We validate the method using an eight participant study in an office environment using an example set of five activity classes: copying a text, reading a printed paper, taking handwritten notes, watching a video, and browsing the Web. We also include periods with no specific activity (the NULL class). Using a support vector machine (SVM) classifier and person-independent (leave-one-person-out) training, we obtain an average precision of 76.1 percent and recall of 70.5 percent over all classes and participants. The work demonstrates the promise of eye-based activity recognition (EAR) and opens up discussion on the wider applicability of EAR to other activities that are difficult, or even impossible, to detect using common sensing modalities.

Adaptation to interocular differences in blur

PubMed Central

Kompaniez, Elysse; Sawides, Lucie; Marcos, Susana; Webster, Michael A.

2013-01-01

Adaptation to a blurred image causes a physically focused image to appear too sharp, and shifts the point of subjective focus toward the adapting blur, consistent with a renormalization of perceived focus. We examined whether and how this adaptation normalizes to differences in blur between the two eyes, which can routinely arise from differences in refractive errors. Observers adapted to images filtered to simulate optical defocus or different axes of astigmatism, as well as to images that were isotropically blurred or sharpened by varying the slope of the amplitude spectrum. Adaptation to the different types of blur produced strong aftereffects that showed strong transfer across the eyes, as assessed both in a monocular adaptation task and in a contingent adaptation task in which the two eyes were simultaneously exposed to different blur levels. Selectivity for the adapting eye was thus generally weak. When one eye was exposed to a sharper image than the other, the aftereffects also tended to be dominated by the sharper image. Our results suggest that while short-term adaptation can rapidly recalibrate the perception of blur, it cannot do so independently for the two eyes, and that the binocular adaptation of blur is biased by the sharper of the two eyes' retinal images. PMID:23729770

Somnambulism induced by quetiapine: two case reports and a review of the literature.

PubMed

Hafeez, Zeba Hasan; Kalinowski, Constance M

2007-12-01

Somnambulism, a previously unreported side effect of quetiapine, is described in two cases. Both cases involved individuals who had no prior or family history of somnambulism and had attention-deficit/hyperactivity disorder. The possible significance of this will also be discussed. Somnambulism is a common parasomnia that reflects an impairment in the normal mechanisms of arousal from sleep in which motor behaviors are activated without full consciousness. Motor behaviors are initiated during deep non-rapid eye movement or slow-wave sleep (stages 3-4), and may be limited to relatively simple manifestations, such as sitting up, fumbling with objects or bedclothes, or mumbling.

Rare nocturnal headaches.

PubMed

Cohen, Anna S; Kaube, Holger

2004-06-01

This review describes rare headaches that can occur at night or during sleep, with a focus on cluster headaches, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing, hypnic headache and exploding head syndrome. It is known that cluster headaches and hypnic headache are associated with rapid eye movement sleep, as illustrated by recent polysomnographic studies. Functional imaging studies have documented hypothalamic activation that is likely to be of relevance to circadian rhythms. These headache syndromes have been shown to respond to melatonin and lithium therapy, both of which have an indirect impact on the sleep-wake cycle. There is growing evidence that cluster headache and hypnic headache are chronobiological disorders.

Effect of combined topical heparin and steroid on corneal neovascularization in children.

PubMed

Michels, Rike; Michels, Stephan; Kaminski, Stephan

2012-01-01

To demonstrate the effect of topical heparin combined with topical steroid on corneal neovascularization (CN) in children. Four children (5 eyes) with new-onset progressive CN in at least one eye received topical rimexolone or dexamethasone in combination with heparin until complete regression of CN was obtained. The regression of CN was documented by slit-lamp or anterior segment photography. All 5 eyes showed complete regression of CN within 5 months. An anti-angiogenic effect was found as early as 1 week after starting topical combination treatment. No ocular and systemic side effects were detected and treatment was well tolerated by all children. In the 3 eyes with involvement of the optical axis, symmetrical visual acuity was obtained by amblyopia treatment. Recurrence of the CN was detectable in 2 eyes at 1 and 6 months, respectively, after ending combination therapy. Both eyes responded favorably to re-treatment. Combination of topical heparin and steroid leads to rapid regression and complete inactivity of CN. This therapeutic approach is promising, especially in children with limited therapeutic alternatives and a high risk for amblyopia. Copyright 2012, SLACK Incorporated.

[The clinical investigation of peripheral retinal changes of anterior uveitis].

PubMed

Guo, Chunying; Qiao, Lijun; Yang, Liu

2015-10-01

To observe the peripheral retinal changes of anterior uveitis patients using ultra-wide field fluorescein angiography. Retrospective case series study. Thirty-three eyes of 20 patients diagnosed as anterior uveitis from September to November 2013 in the ophthalmic clinic of Peking University First Hospital was included. All the patients underwent routine ocular examination, followed by ultra-wide field Fluorescein. There were 13 male patients and 7 female patients, aged 23-66, an average of 46 years old. The anterior uveitis recurrent in both eyes in 13 patients and only one eye in 7 patients. Uveitis duration ranging from months to 30 years. Twenty eyes were at the active stage of the anterior uveitis while 13 eyes in the quiescent stage. Peripheral retinal vessels leakage was detected in 57.6% (19/33) of the eyes, among which in eyes with active disease the rate of peripheral retinal vessels leakage was 75% (15/20), and in eyes with quiescent disease the rate was 30.8% (4/13). Optic disk hyperfluorescence was found in 6 of 20 eyes with active disease. Cystoid macular edema was found in 4 eyes. In addition, peripheral retinal hyperfluorescence dot and zone were detected in 2 eyes. Peripheral retinal vessels were detected to have inflammative leakage in patients of anterior uveitis by ultra-wide field fluorescein agiography. Peripheral retinal inflammation may still exist even in the quiescent stage of the anterior uveitis.

Therapeutic Potential of Mesenchymal Stem Cell-Derived Exosomes in the Treatment of Eye Diseases.

PubMed

Harrell, C Randall; Simovic Markovic, Bojana; Fellabaum, Crissy; Arsenijevic, Aleksandar; Djonov, Valentin; Arsenijevic, Nebojsa; Volarevic, Vladislav

2018-05-18

Mesenchymal stem cells (MSCs) were, due to their immunomodulatory and pro-angiogenic characteristics, extensively explored as new therapeutic agents in cell-based therapy of uveitis, glaucoma, retinal and ocular surface diseases.Since it was recently revealed that exosomes play an important role in biological functions of MSCs, herewith we summarized current knowledge about the morphology, structure, phenotype and functional characteristics of MSC-derived exosomes emphasizing their therapeutic potential in the treatment of eye diseases.MSC-derived exosomes were as efficient as transplanted MSCs in limiting the extent of eye injury and inflammation. Immediately after intravitreal injection, MSC-derived exosomes, due to nano-dimension, diffused rapidly throughout the retina and significantly attenuated retinal damage and inflammation. MSC-derived exosomes successfully delivered trophic and immunomodulatory factors to the inner retina and efficiently promoted survival and neuritogenesis of injured retinal ganglion cells. MSC-derived exosomes efficiently suppressed migration of inflammatory cells, attenuated detrimental Th1 and Th17 cell-driven immune response and ameliorated experimental autoimmune uveitis. MSC-derived exosomes were able to fuse with the lysosomes within corneal cells, enabling delivering of MSC-derived active β-glucuronidase and consequent catabolism of accumulated glycosaminoglycans, indicating their therapeutic potential in the treatment of Mucopolysaccharidosis VII (Sly Syndrome). Importantly, beneficent effects were noticed only in animals that received MSC-derived exosomes and were not seen after therapy with fibroblasts-derived exosomes confirming specific therapeutic potential of MSCs and their products in the treatment of eye diseases.In conclusion, MSC-derived exosomes represent potentially new therapeutic agents in the therapy of degenerative and inflammatory ocular diseases.

Posttraining Increases in REM Sleep Intensity Implicate REM Sleep in Memory Processing and Provide a Biological Marker of Learning Potential

ERIC Educational Resources Information Center

Nader, Rebecca S.; Smith, Carlyle T.; Nixon, Margaret R.

2004-01-01

Posttraining rapid eye movement (REM) sleep has been reported to be important for efficient memory consolidation. The present results demonstrate increases in the intensity of REM sleep during the night of sleep following cognitive procedural/implicit task acquisition. These REM increases manifest as increases in total number of rapid eye…

Roles of ADAM13-regulated Wnt activity in early Xenopus eye development

PubMed Central

Wei, Shuo; Xu, Guofeng; Bridges, Lance C.; Williams, Phoebe; Nakayama, Takuya; Shah, Anoop; Grainger, Robert M.; White, Judith M.; DeSimone, Douglas W.

2012-01-01

Pericellular proteolysis by ADAM family metalloproteinases has been widely implicated in cell signaling and development. We recently found that Xenopus ADAM13, an ADAM metalloproteinase, is required for activation of canonical Wnt signaling during cranial neural crest (CNC) induction by regulating a novel crosstalk between Wnt and ephrin B (EfnB) signaling pathways (Wei et al., 2010b). In the present study we show that the metalloproteinase activity of ADAM13 also plays important roles in eye development in X. tropicalis. Knockdown of ADAM13 results in reduced expression of eye field markers pax6 and rx1, as well as that of the pan-neural marker sox2. Activation of canonical Wnt signaling or inhibition of forward EfnB signaling rescues the eye defects caused by loss of ADAM13, suggesting that ADAM13 functions through regulation of the EfnB-Wnt pathway interaction. Downstream of Wnt, the head inducer Cerberus was identified as an effector that mediates ADAM13 function in early eye field formation. Furthermore, ectopic expression of the Wnt target gene snail2 restores cerberus expression and rescues the eye defects caused by ADAM13 knockdown. Together these data suggest an important role of ADAM13-regulated Wnt activity in eye development in Xenopus. PMID:22227340

Optic neuritis and rapidly progressive necrotizing retinitis as the initial signs of subacute sclerosing panencephalitis: a case report with clinical and histopathologic findings.

PubMed

Oray, Merih; Tuncer, Samuray; Kir, Nur; Karacorlu, Murat; Tugal-Tutkun, Ilknur

2014-08-01

We report a case of subacute sclerosing panencephalitis (SSPE) presenting first with optic neuritis and rapidly progressive necrotizing retinitis at the posterior pole. We reviewed the clinical, laboratory, photographic, angiographic, and histopathologic records of a patient with SSPE. A 15-year-old girl was referred after rapid loss of vision due to optic neuritis and macular necrosis in the right eye. She had a history of cardiac valve surgery, but had no systemic symptoms and extensive work-up was unrewarding. Contralateral involvement with rapidly progressive optic neuritis and macular necrotizing retinitis prompted retinochoroidal biopsy of the right eye, which revealed necrosis of inner retinal layers and perivascular lymphoplasmocytic infiltration with intact choroid and outer retina without any findings of inclusion bodies, microorganisms, or atypical cells. The diagnosis was based on histopathologic findings consistent with SSPE, and detection of elevated measles antibody titers in cerebrospinal fluid and serum. It was further confirmed by development of typical electroencephalography pattern at 6 months and neurological symptoms at 4-year follow-up. Clinicians need to be aware that optic neuritis and necrotizing retinitis at the posterior pole may be the presenting features of SSPE.

The King-Devick (K-D) test of rapid eye movements: a bedside correlate of disability and quality of life in MS.

PubMed

Moster, Stephen; Wilson, James A; Galetta, Steven L; Balcer, Laura J

2014-08-15

We investigated the King-Devick (K-D) test of rapid number naming as a visual performance measure in a cohort of patients with multiple sclerosis (MS). In this cross-sectional study, 81 patients with MS and 20 disease-free controls from an ongoing study of visual outcomes underwent K-D testing. A test of rapid number naming, K-D requires saccadic eye movements as well as intact vision, attention and concentration. To perform the K-D test, participants are asked to read numbers aloud as quickly as possible from three test cards; the sum of the three test card times in seconds constitutes the summary score. High-contrast visual acuity (VA), low-contrast letter acuity (1.25% and 2.5% levels), retinal nerve fiber layer (RNFL) thickness by optical coherence tomography (OCT), MS Functional Composite (MSFC) and vision-specific quality of life (QOL) measures (25-Item NEI Visual Functioning Questionnaire [NEI-VFQ-25] and 10-Item Neuro-Ophthalmic Supplement) were also assessed. K-D time scores in the MS cohort (total time to read the three test cards) were significantly higher (worse) compared to those for disease-free controls (P=0.003, linear regression, accounting for age). Within the MS cohort, higher K-D scores were associated with worse scores for the NEI-VFQ-25 composite (P<0.001), 10-Item Neuro-Ophthalmic Supplement (P<0.001), binocular low-contrast acuity (2.5%, 1.25%, P<0.001, and high-contrast VA (P=0.003). Monocular low-contrast vision scores (P=0.001-0.009) and RNFL thickness (P=0.001) were also reduced in eyes of patients with worse K-D scores (GEE models accounting for age and within-patient, inter-eye correlations). Patients with a history of optic neuritis (ON) had increased (worse) K-D scores. Patients who classified their work disability status as disabled (receiving disability pension) did worse on K-D testing compared to those working full-time (P=0.001, accounting for age). The K-D test, a <2 minute bedside test of rapid number naming, is associated with visual dysfunction, neurologic impairment, and reduced vision-specific QOL in patients with MS. Scores reflect work disability as well as structural changes as measured by OCT imaging. History of ON and abnormal binocular acuities were associated with worse K-D scores, suggesting that abnormalities detected by K-D may go along with afferent dysfunction in MS patients. A brief test that requires saccadic eye movements, K-D should be considered for future MS trials as a rapid visual performance measure. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of eye rubbing on the levels of protease, protease activity and cytokines in tears: relevance in keratoconus.

PubMed

Balasubramanian, Sivaraman A; Pye, David C; Willcox, Mark D P

2013-03-01

Proteases, protease activity and inflammatory molecules in tears have been found to be relevant in the pathogenesis of keratoconus. We sought to determine the influence of eye rubbing on protease expression, protease activity and concentration of inflammatory molecules in tears. Basal tears were collected from normal volunteers before and after 60 seconds of experimental eye rubbing. The total amount of matrix metalloproteinase (MMP)-13 and inflammatory molecules interleukin (IL)-6 and tumour necrosis factor (TNF)-α in the tear samples were measured using specific enzyme-linked immunosorbent assays (ELISA). Tear collagenase activity was investigated using a specific activity assay. The concentrations of MMP-13 (51.9 ± 34.3 versus 63 ± 36.8 pg/ml, p = 0.006), IL-6 (1.24 ± 0.98 versus 2.02 ± 1.52 pg/ml, p = 0.004) and TNF-α (1.16 ± 0.74 versus 1.44 ± 0.66 pg/ml, p = 0.003) were significantly increased in normal subjects after eye rubbing. The experimental eye rub did not alter significantly the collagenase activity (5.02 ± 3 versus 7.50 ± 3.90 fluorescent intensity units, p = 0.14) of tears. Eye rubbing for 60 seconds increased the level of tear MMP-13, IL-6 and TNF-α in normal study subjects. This increase in protease, protease activity and inflammatory mediators in tears after eye rubbing may be exacerbated even further during persistent and forceful eye rubbing seen in people with keratoconus and this in turn may contribute to the progression of the disease. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

Rapid diagnosis of acanthamoeba keratitis using non-nutrient agar with a lawn of E. coli.

PubMed

Borin, Samuel; Feldman, Ilan; Ken-Dror, Shifra; Briscoe, Daniel

2013-02-27

A patient presented with a corneal foreign body in his only eye. He was treated with prophylactic antibiotics and sent home, but deteriorated. He returned to the hospital 5 days later, and on slit-lamp examination, there was ciliary injection, corneal oedema and a 1 mm × 1 mm corneal abscess with mild anterior uveitis. Corneal scrapings were taken for culture on a non-nutrient agar with a lawn of Escherichia coli, on chocolate agar and on blood agar. He was treated with fortified gentamicin and cefazolin drops. He improved and was discharged 4 days after admission. On day 5, the culture results showed acanthamoeba. He was brought back to the hospital and treated with hourly chlorhexidine drops, ofloxacin six times daily and neomycin/dexamethasone drops once daily. On day 7, he was discharged to continue treatment at home, at which time his visual acuity in that eye was 6/9, and slit-lamp examination showed punctate keratitis and a stromal opacity with mild peripheral infiltration. Culture on non-nutrient agar with a lawn of E. coli is a rapid, reliable and less invasive alternative to corneal biopsy for the diagnosis of acanthamoeba infection. We suggest using this method where acanthamoeba is suspected. Owing to the risk of corneal abscess, orthokeratology should be avoided in an amblyopic patient or an only eye. Acanthamoeba infection may be masked by other eye diseases.

Animal spotting in Alzheimer's disease: an eye tracking study of object categorization.

PubMed

Boucart, Muriel; Bubbico, Giovanna; Szaffarczyk, Sébastien; Pasquier, Florence

2014-01-01

We investigated rapid object categorization and, more specifically, the ability to detect a target object within a natural scene in people with mild Alzheimer's disease (AD) using a saccadic choice task. It has been suggested that the anatomical pathway likely used to initiate rapid oculomotor responses in the saccadic choice task could involve the Frontal Eye Field, a structure that is part of the dorsal attentional network, in which connectivity is disrupted in AD. Seventeen patients with mild AD and 23 healthy age-matched controls took part in the study. A group of 24 young healthy observers was included as it has been reported that normal aging affects eye movements. Participants were presented with pairs of colored photographs of natural scenes, one containing an animal (the target) and one containing various objects (distracter), displayed for 1 s left and right of fixation. They were asked to saccade to the scene containing an animal. Neither pathology nor age affected temporal (saccade latencies and durations) and spatial (saccade amplitude) parameters of eye movements. Patients with AD were significantly less accurate than age-matched controls, and older participants were less accurate than young observers. The results are interpreted in terms of noisier sensory information and increased uncertainty in relation to deficits in the magnocellular pathway. The results suggest that, even at a mild stage of the pathology, people exhibit difficulties in selecting relevant objects.

Sensitization of Depressive-like Behavior during Repeated Maternal Separation is Associated with More-Rapid Increase in Core Body Temperature and Reduced Plasma Cortisol Levels

PubMed Central

Yusko, Brittany; Hawk, Kiel; Schiml, Patricia A.; Deak, Terrence; Hennessy, Michael B.

2011-01-01

Infant guinea pigs exhibit a 2-stage response to maternal separation: an initial active stage, characterized by vocalizing, and a second passive stage marked by depressive-like behavior (hunched posture, prolonged eye-closure, extensive piloerection) that appears to be mediated by proinflammatory activity. Recently we found that pups showed an enhanced (i.e., sensitized) depressive-like behavioral response during repeated separation. Further, core body temperature was higher during the beginning of a second separation compared to the first, suggesting a more-rapid stress-induced febrile response to separation the second day, though the possibility that temperature was already elevated prior to the second separation could not be ruled out. Therefore, the present study examined temperature prior to, and during, 2 daily separations. We also examined the temperature response to a third separation conducted 3 days after the second, and assessed the effect of repeated separation on plasma cortisol levels. Core temperature did not differ just prior to the separations, but showed a more-rapid increase and then decline during both a second and third separation than during a first. Temperature responses were not associated with changes in motor activity. Depressive-like behavior was greater during the second and third separations. Pups separated a first time showed a larger plasma cortisol response at the conclusion of separation than did animals of the same age separated a third time. In all, the results indicate that the sensitization of depressive-like behavior during repeated separations over several days is accompanied by a more-rapid febrile response that may be related to a reduction of glucocorticoid suppression. PMID:22079581

Effect of prophylactic topical hypotensive medications in reducing the incidence of postoperative ocular hypertension after phacoemulsification in dogs.

PubMed

Dees, D Dustin; Spahn, Kate J; Wagner, Lynsey Smith; Greller, Andrew; Paglia, Danielle; Armour, Micki D; Madsen, Richard

2017-11-01

To determine whether topical hypotensive medications prevent postoperative ocular hypertension (POH) after phacoemulsification. 52 client-owned dogs (88 eyes). Diabetic and nondiabetic dogs having undergone phacoemulsification were included in this retrospective study. The control group received no ocular hypotensive medications. The treatment groups received latanoprost, dorzolamide, or dorzolamide/timolol, beginning immediately after surgery, for 2-week duration. IOPs were obtained at initial examination followed by 4 h, 24 h, 7 days, and 14 days postoperatively. POH was defined as an IOP above 20 mmHg (POH20) or 25 mmHg (POH25). POH20 occurred in 33 of 87 eyes (37.93%), including 11 of 21 eyes (52.38%) in the control group, three of 23 eyes (13.04%) in the latanoprost group, eight of 15 eyes (53.33%) in the dorzolamide group, and 11 of 28 eyes (39.29%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.11). POH25 occurred in 22 of 86 eyes (25.58%), including seven of 21 eyes (33.33%) in the control group, two of 23 eyes (8.70%) in the latanoprost group, five of 15 eyes (33.33%) in the dorzolamide group, and eight of 27 eyes (29.63%) in the dorzolamide/timolol group. Active treatment groups were compared to the control group, and the overall group effect was not significant (P = 0.31). Intraoperative use of intracameral tissue plasminogen activator significantly decreased the chances of POH25 (P = 0.0063). The latanoprost group had a substantially lower percentage of POH 20 and POH25 compared to the control and other active treatment groups, although statistical significance was not achieved. Intraoperative intracameral tissue plasminogen activator decreased the incidence of POH25. © 2017 American College of Veterinary Ophthalmologists.

Subretinal fluid in eyes with active ocular toxoplasmosis observed using spectral domain optical coherence tomography.

PubMed

Ouyang, Yanling; Li, Fuqiang; Shao, Qing; Heussen, Florian M; Keane, Pearse A; Stübiger, Nicole; Sadda, Srinivas R; Pleyer, Uwe

2015-01-01

To describe the clinical finding of subretinal fluid (SRF) in the posterior pole by spectral domain optical coherence tomography (SD-OCT) in eyes with active ocular toxoplasmosis (OT). Retrospective case series. Thirty-nine eyes from 38 patients with active OT [corrected].. Eyes with active OT which underwent SD-OCT were reviewed. SRFs in the posterior pole were further analyzed. Presence of SRF; its accompanying features, e.g. retinal necrosis, cystoid macular edema (CME), choroidal neovascularization (CNV); and longitudinal changes of SRF, including maximum height and total volume before and after treatment. SRF presented in 45.5% (or 15/33) of eyes with typical active OT and in 51.3% (or 20/39) of eyes with active OT. The mean maximum height and total volume of SRF were 161.0 (range: 23-478) µm and 0.47 (range: 0.005-4.12) mm3, respectively. For 12 eyes with SRF related to active retinal necrosis, SRF was observed with complete absorption after conventional anti-toxoplasmosis treatment. The mean duration for observation of SRF clearance was 33.8 (range: 7-84) days. The mean rate of SRF clearance was 0.0128 (range: 0.0002-0.0665) mm3/day. SRF (i.e., serous retinal detachment) is a common feature in patients with active OT when SD-OCT is performed. The majority of SRF was associated with retinal necrosis and reacted well to conventional therapy, regardless of total fluid volume. However, SRF accompanying with CME or CNV responded less favorably or remained refractory to conventional or combined intravitreal treatment, even when the SRF was small in size.

Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex

PubMed Central

Adams, Daniel L.; Economides, John R.

2015-01-01

To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns. PMID:25810480

Contrasting effects of strabismic amblyopia on metabolic activity in superficial and deep layers of striate cortex.

PubMed

Adams, Daniel L; Economides, John R; Horton, Jonathan C

2015-05-01

To probe the mechanism of visual suppression, we have raised macaques with strabismus by disinserting the medial rectus muscle in each eye at 1 mo of age. Typically, this operation produces a comitant, alternating exotropia with normal acuity in each eye. Here we describe an unusual occurrence: the development of severe amblyopia in one eye of a monkey after induction of exotropia. Shortly after surgery, the animal demonstrated a strong fixation preference for the left eye, with apparent suppression of the right eye. Later, behavioral testing showed inability to track or to saccade to targets with the right eye. With the left eye occluded, the animal demonstrated no visually guided behavior. Optokinetic nystagmus was absent in the right eye. Metabolic activity in striate cortex was assessed by processing the tissue for cytochrome oxidase (CO). Amblyopia caused loss of CO in one eye's rows of patches, presumably those serving the blind eye. Layers 4A and 4B showed columns of reduced CO, in register with pale rows of patches in layer 2/3. Layers 4C, 5, and 6 also showed columns of CO activity, but remarkably, comparison with more superficial layers showed a reversal in contrast. In other words, pale CO staining in layers 2/3, 4A, and 4B was aligned with dark CO staining in layers 4C, 5, and 6. No experimental intervention or deprivation paradigm has been reported previously to produce opposite effects on metabolic activity in layers 2/3, 4A, and 4B vs. layers 4C, 5, and 6 within a given eye's columns. Copyright © 2015 the American Physiological Society.

Effect of a single 3-hour exposure to bright light on core body temperature and sleep in humans.

PubMed

Dijk, D J; Cajochen, C; Borbély, A A

1991-01-02

Seven human subjects were exposed to bright light (BL, approx. 2500 lux) and dim light (DL, approx. 6 lux) during 3 h prior to nocturnal sleep, in a cross-over design. At the end of the BL exposure period core body temperature was significantly higher than at the end of the DL exposure period. The difference in core body temperature persisted during the first 4 h of sleep. The latency to sleep onset was increased after BL exposure. Rapid-eye movement sleep (REMS) and slow-wave sleep (SWS; stage 3 + 4 of non-REMS) were not significantly changed. Eight subjects were exposed to BL from 20.30 to 23.30 h while their eyes were covered or uncovered. During BL exposure with uncovered eyes, core body temperature decreased significantly less than during exposure with covered eyes. We conclude that bright light immediately affects core body temperature and that this effect is mediated via the eyes.

Acute shallowing of the anterior chamber.

PubMed Central

Mapstone, R

1981-01-01

In aging eyes phenylephrine drops have no significant effect on the depth of the anterior chamber, whereas pilocarpine drops produce a significant shallowing. If both drugs are instilled simultaneously, a significantly greater decrease in anterior chamber depth occurs. The effect is seen in normal, glaucomatous, and hypertensive eyes, and in eyes with shallow anterior chambers. It did not occur in eyes that had had an iridectomy. During the course of a positive provocative test an acute reduction in anterior depth occurs which is reversed when the angle opens and pressure returns to normal levels. It is concluded that the depth of the anterior chamber is not a static dimension but that changes can occur which are rapid and transient. The mechanism of shallowing and deepening depends on an increase or a decrease in the pupil block force. It is a necessary consequence too that eyes with nonshallow anterior chambers can get closed-angle glaucoma and that this possibility cannot be detected by a conventional gonioscopic approach. PMID:6455153

Effects of individual differences in verbal skills on eye-movement patterns during sentence reading

PubMed Central

Kuperman, Victor; Van Dyke, Julie A.

2011-01-01

This study is a large-scale exploration of the influence that individual reading skills exert on eye-movement behavior in sentence reading. Seventy one non-college-bound 16–24 year-old speakers of English completed a battery of 18 verbal and cognitive skill assessments, and read a series of sentences as their eye movements were monitored. Statistical analyses were performed to establish what tests of reading abilities were predictive of eye-movement patterns across this population and how strong the effects were. We found that individual scores in rapid automatized naming and word identification tests (i) were the only participant variables with reliable predictivity throughout the time-course of reading; (ii) elicited effects that superceded in magnitude the effects of established predictors like word length or frequency; and (iii) strongly modulated the influence of word length and frequency on fixation times. We discuss implications of our findings for testing reading ability, as well as for research of eye-movements in reading. PMID:21709808

Auditory Responses and Stimulus-Specific Adaptation in Rat Auditory Cortex are Preserved Across NREM and REM Sleep

PubMed Central

Nir, Yuval; Vyazovskiy, Vladyslav V.; Cirelli, Chiara; Banks, Matthew I.; Tononi, Giulio

2015-01-01

Sleep entails a disconnection from the external environment. By and large, sensory stimuli do not trigger behavioral responses and are not consciously perceived as they usually are in wakefulness. Traditionally, sleep disconnection was ascribed to a thalamic “gate,” which would prevent signal propagation along ascending sensory pathways to primary cortical areas. Here, we compared single-unit and LFP responses in core auditory cortex as freely moving rats spontaneously switched between wakefulness and sleep states. Despite robust differences in baseline neuronal activity, both the selectivity and the magnitude of auditory-evoked responses were comparable across wakefulness, Nonrapid eye movement (NREM) and rapid eye movement (REM) sleep (pairwise differences <8% between states). The processing of deviant tones was also compared in sleep and wakefulness using an oddball paradigm. Robust stimulus-specific adaptation (SSA) was observed following the onset of repetitive tones, and the strength of SSA effects (13–20%) was comparable across vigilance states. Thus, responses in core auditory cortex are preserved across sleep states, suggesting that evoked activity in primary sensory cortices is driven by external physical stimuli with little modulation by vigilance state. We suggest that sensory disconnection during sleep occurs at a stage later than primary sensory areas. PMID:24323498

The 120-S minute: using analysis of work activity to prevent psychological distress among elementary school teachers.

PubMed

Messing, K; Seifert, A M; Escalona, E

1997-01-01

Primary school teachers in Québec suffer psychological distress, as shown by the Québec Health Survey (M. Gervais, 1993; Santè Québec, 1995). The authors applied and extended the French model (F. Guérin, A. Laville, F. Daniellou, J. Duraffourg, & A. Kerguelen, 1991) of analysis of work activity to observing classroom teaching (14 women in 10 classrooms for a total of 48 hr 24 min) to identify stressful elements. The authors observed a rapid sequence of actions, eye fixations of short duration, little physical or mental relaxation, multiple simultaneous activities, and uncomfortable temperature and humidity levels. Teachers use many strategies to teach, to create a learning environment, and to maintain attention in classrooms under adverse conditions. Examination of these strategies led to recommendations to improve relations between the teachers and their supervisors and to make the classroom an easier place to teach.

Cognitive and emotional processes during dreaming: a neuroimaging view.

PubMed

Desseilles, Martin; Dang-Vu, Thien Thanh; Sterpenich, Virginie; Schwartz, Sophie

2011-12-01

Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation. Copyright © 2010 Elsevier Inc. All rights reserved.

Estimation of Mangrove Forest Aboveground Biomass Using Multispectral Bands, Vegetation Indices and Biophysical Variables Derived from Optical Satellite Imageries: Rapideye, Planetscope and SENTINEL-2

NASA Astrophysics Data System (ADS)

Balidoy Baloloy, Alvin; Conferido Blanco, Ariel; Gumbao Candido, Christian; Labadisos Argamosa, Reginal Jay; Lovern Caboboy Dumalag, John Bart; Carandang Dimapilis, Lee, , Lady; Camero Paringit, Enrico

2018-04-01

Aboveground biomass estimation (AGB) is essential in determining the environmental and economic values of mangrove forests. Biomass prediction models can be developed through integration of remote sensing, field data and statistical models. This study aims to assess and compare the biomass predictor potential of multispectral bands, vegetation indices and biophysical variables that can be derived from three optical satellite systems: the Sentinel-2 with 10 m, 20 m and 60 m resolution; RapidEye with 5m resolution and PlanetScope with 3m ground resolution. Field data for biomass were collected from a Rhizophoraceae-dominated mangrove forest in Masinloc, Zambales, Philippines where 30 test plots (1.2 ha) and 5 validation plots (0.2 ha) were established. Prior to the generation of indices, images from the three satellite systems were pre-processed using atmospheric correction tools in SNAP (Sentinel-2), ENVI (RapidEye) and python (PlanetScope). The major predictor bands tested are Blue, Green and Red, which are present in the three systems; and Red-edge band from Sentinel-2 and Rapideye. The tested vegetation index predictors are Normalized Differenced Vegetation Index (NDVI), Soil-adjusted Vegetation Index (SAVI), Green-NDVI (GNDVI), Simple Ratio (SR), and Red-edge Simple Ratio (SRre). The study generated prediction models through conventional linear regression and multivariate regression. Higher coefficient of determination (r2) values were obtained using multispectral band predictors for Sentinel-2 (r2 = 0.89) and Planetscope (r2 = 0.80); and vegetation indices for RapidEye (r2 = 0.92). Multivariate Adaptive Regression Spline (MARS) models performed better than the linear regression models with r2 ranging from 0.62 to 0.92. Based on the r2 and root-mean-square errors (RMSE's), the best biomass prediction model per satellite were chosen and maps were generated. The accuracy of predicted biomass maps were high for both Sentinel-2 (r2 = 0.92) and RapidEye data (r2 = 0.91).

Small reduction of neurokinin-1 receptor-expressing neurons in the pre-Bötzinger complex area induces abnormal breathing periods in awake goats.

PubMed

Wenninger, J M; Pan, L G; Klum, L; Leekley, T; Bastastic, J; Hodges, M R; Feroah, T; Davis, S; Forster, H V

2004-11-01

In awake rats, >80% bilateral reduction of neurokinin-1 receptor (NK1R)-expressing neurons in the pre-Bötzinger complex (pre-BötzC) resulted in hypoventilation and an "ataxic" breathing pattern (Gray PA, Rekling JC, Bocchiaro CM, Feldman JL, Science 286: 1566-1568, 1999). Accordingly, the present study was designed to gain further insight into the role of the pre-BötzC area NK1R-expressing neurons in the control of breathing during physiological conditions. Microtubules were chronically implanted bilaterally into the medulla of adult goats. After recovery from surgery, the neurotoxin saporin conjugated to substance P, specific for NK1R-expressing neurons, was bilaterally injected (50 pM in 10 microl) into the pre-BötzC area during the awake state (n = 8). In unoperated goats, 34 +/- 0.01% of the pre-BötzC area neurons are immunoreactive for the NK1R, but, in goats after bilateral injection of SP-SAP into the pre-BötzC area, NK1R immunoreactivity was reduced to 22.5 +/- 2.5% (29% decrease, P < 0.01). Ten to fourteen days after the injection, the frequency of abnormal breathing periods was sixfold greater than before injection (107.8 +/- 21.8/h, P < 0.001). Fifty-six percent of these periods were breaths of varying duration and volume with an altered respiratory muscle activation pattern, whereas the remaining were rapid, complete breaths with coordinated inspiratory-expiratory cycles. The rate of occurrence and characteristics of abnormal breathing periods were not altered during a CO2 inhalation-induced hyperpnea. Pathological breathing patterns were eliminated during non-rapid eye movement sleep in seven of eight goats, but they frequently occurred on arousal from non-rapid eye movement sleep. We conclude that a moderate reduction in pre-BötzC NK1R-expressing neurons results in state-dependent transient changes in respiratory rhythm and/or eupneic respiratory muscle activation patterns.

Dry Eye as a Mucosal Autoimmune Disease

PubMed Central

Stern, Michael E.; Schaumburg, Chris S.; Pflugfelder, Stephen C.

2013-01-01

Dry eye is a common ocular surface inflammatory disease that significantly affects quality of life. Dysfunction of the lacrimal function unit (LFU) alters tear composition and breaks ocular surface homeostasis, facilitating chronic inflammation and tissue damage. Accordingly, the most effective treatments to date are geared towards reducing inflammation and restoring normal tear film. The pathogenic role of CD4+ T cells is well known, and the field is rapidly realizing the complexity of other innate and adaptive immune factors involved in the development and progression of disease. The data support the hypothesis that dry eye is a localized autoimmune disease originating from an imbalance in the protective immunoregulatory and proinflammatory pathways of the ocular surface. PMID:23360156

Vision in our three-dimensional world

PubMed Central

2016-01-01

Many aspects of our perceptual experience are dominated by the fact that our two eyes point forward. Whilst the location of our eyes leaves the environment behind our head inaccessible to vision, co-ordinated use of our two eyes gives us direct access to the three-dimensional structure of the scene in front of us, through the mechanism of stereoscopic vision. Scientific understanding of the different brain regions involved in stereoscopic vision and three-dimensional spatial cognition is changing rapidly, with consequent influences on fields as diverse as clinical practice in ophthalmology and the technology of virtual reality devices. This article is part of the themed issue ‘Vision in our three-dimensional world’. PMID:27269595

The relationship between the lizard eye and associated bony features: a cautionary note for interpreting fossil activity patterns.

PubMed

Hall, Margaret I

2009-06-01

Activity pattern, the time of day when an animal is active, is associated with ecology. There are two major activity patterns: diurnal (awake during the day in a photopic environment) and nocturnal (awake at night in a scotopic environment). Lizards exhibit characteristic eye shapes associated with activity pattern, with scotopic-adapted lizard eyes optimized for visual sensitivity with large corneal diameters relative to their eye axial lengths, and photopic-adapted lizards optimized for visual acuity, with larger axial lengths of the eye relative to their corneal diameters. This study: (1) quantifies the relationship between the lizard eye and its associated bony anatomy (the orbit, sclerotic ring, and associated skull widths); (2) investigates how activity pattern is reflected in that bony anatomy; and (3) determines if it is possible to reliably interpret activity pattern for a lizard that does not have the soft tissue available for study, specifically, for a fossil. Knowledge of extinct lizards' activity patterns would be useful in making paleoecological interpretations. Here, 96 scotopic- and photopic-adapted lizard species are analyzed in a phylogenetic context. Although there is a close relationship between the lepidosaur eye and associated bony anatomy, based on these data activity pattern cannot be reliably interpreted for bony-only specimens, such as a fossil, possibly because of the limited ossification of the lepidosaur skull. Caution should be exercised when utilizing lizard bony anatomy to interpret light-level adaptation, either for a fossil lizard or as part of an extant phylogenetic bracket to interpret other extinct animals with sclerotic rings, such as dinosaurs. (c) 2009 Wiley-Liss, Inc.

Sleep alterations in mammals: did aquatic conditions inhibit rapid eye movement sleep?

PubMed

Madan, Vibha; Jha, Sushil K

2012-12-01

Sleep has been studied widely in mammals and to some extent in other vertebrates. Higher vertebrates such as birds and mammals have evolved an inimitable rapid eye movement (REM) sleep state. During REM sleep, postural muscles become atonic and the temperature regulating machinery remains suspended. Although REM sleep is present in almost all the terrestrial mammals, the aquatic mammals have either radically reduced or completely eliminated REM sleep. Further, we found a significant negative correlation between REM sleep and the adaptation of the organism to live on land or in water. The amount of REM sleep is highest in terrestrial mammals, significantly reduced in semi-aquatic mammals and completely absent or negligible in aquatic mammals. The aquatic mammals are obligate swimmers and have to surface at regular intervals for air. Also, these animals live in thermally challenging environments, where the conductive heat loss is approximately ~90 times greater than air. Therefore, they have to be moving most of the time. As an adaptation, they have evolved unihemispheric sleep, during which they can rove as well as rest. A condition that immobilizes muscle activity and suspends the thermoregulatory machinery, as happens during REM sleep, is not suitable for these animals. It is possible that, in accord with Darwin's theory, aquatic mammals might have abolished REM sleep with time. In this review, we discuss the possibility of the intrinsic role of aquatic conditions in the elimination of REM sleep in the aquatic mammals.

Sleep-Disordered Breathing in Neuromuscular Disease: Diagnostic and Therapeutic Challenges.

PubMed

Aboussouan, Loutfi S; Mireles-Cabodevila, Eduardo

2017-10-01

Normal sleep-related rapid eye movement sleep atonia, reduced lung volumes, reduced chemosensitivity, and impaired airway dilator activity become significant vulnerabilities in the setting of neuromuscular disease. In that context, the compounding effects of respiratory muscle weakness and disease-specific features that promote upper airway collapse or cause dilated cardiomyopathy contribute to various sleep-disordered breathing events. The reduction in lung volumes with neuromuscular disease is further compromised by sleep and the supine position, exaggerating the tendency for upper airway collapse and desaturation with sleep-disordered breathing events. The most commonly identified events are diaphragmatic/pseudo-central, due to a decrease in the rib cage contribution to the tidal volume during phasic rapid eye movement sleep. Obstructive and central sleep apneas are also common. Noninvasive ventilation can improve survival and quality of sleep but should be used with caution in the context of dilated cardiomyopathy or significant bulbar symptoms. Noninvasive ventilation can also trigger sleep-disordered breathing events, including ineffective triggering, autotriggering, central sleep apnea, and glottic closure, which compromise the potential benefits of the intervention by increasing arousals, reducing adherence, and impairing sleep architecture. Polysomnography plays an important diagnostic and therapeutic role by correctly categorizing sleep-disordered events, identifying sleep-disordered breathing triggered by noninvasive ventilation, and improving noninvasive ventilation settings. Optimal management may require dedicated hypoventilation protocols and a technical staff well versed in the identification and troubleshooting of respiratory events. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

[Eye contact in adult patients with Asperger syndrome].

PubMed

Roy, M; Wolfgang, D

2015-05-01

It is unclear if individuals with autism spectrum disorders rarely hold direct eye contact because eyes are unimportant for them, or if it is actively avoided. The aim of the current investigation was to gain a better understanding for their views on direct eye contact by exploring adult patients with Asperger syndrome. 63 adult patients with Asperger syndrome (28 females, 35 males, 21 - 62 years old) were explored about using and sensing direct eye contact by means of a standardised questionnaire. 87 % of investigated patients depict direct eye contact as being disagreeable. They describe it as arduous and distracting. Therefore they mostly actively avoid direct eye contact. The here gained knowledge about aversion towards direct eye contact in individuals with autism should lead to a stronger understanding and acceptance of this problem in the non-autistic population. © Georg Thieme Verlag KG Stuttgart · New York.

Prediction of muscle activation for an eye movement with finite element modeling.

PubMed

Karami, Abbas; Eghtesad, Mohammad; Haghpanah, Seyyed Arash

2017-10-01

In this paper, a 3D finite element (FE) modeling is employed in order to predict extraocular muscles' activation and investigate force coordination in various motions of the eye orbit. A continuum constitutive hyperelastic model is employed for material description in dynamic modeling of the extraocular muscles (EOMs). Two significant features of this model are accurate mass modeling with FE method and stimulating EOMs for motion through muscle activation parameter. In order to validate the eye model, a forward dynamics simulation of the eye motion is carried out by variation of the muscle activation. Furthermore, to realize muscle activation prediction in various eye motions, two different tracking-based inverse controllers are proposed. The performance of these two inverse controllers is investigated according to their resulted muscle force magnitude and muscle force coordination. The simulation results are compared with the available experimental data and the well-known existing neurological laws. The comparison authenticates both the validation and the prediction results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Eye-specific retinogeniculate segregation proceeds normally following disruption of patterned spontaneous retinal activity.

PubMed

Speer, Colenso M; Sun, Chao; Liets, Lauren C; Stafford, Ben K; Chapman, Barbara; Cheng, Hwai-Jong

2014-11-07

Spontaneous retinal activity (SRA) is important during eye-specific segregation within the dorsal lateral geniculate nucleus (dLGN), but the feature(s) of activity critical for retinogeniculate refinement are controversial. Pharmacologically or genetically manipulating cholinergic signaling during SRA perturbs correlated retinal ganglion cell (RGC) spiking and disrupts eye-specific retinofugal refinement in vivo, consistent with an instructive role for SRA during visual system development. Paradoxically, ablating the starburst amacrine cells (SACs) that generate cholinergic spontaneous activity disrupts correlated RGC firing without impacting retinal activity levels or eye-specific segregation in the dLGN. Such experiments suggest that patterned SRA during retinal waves is not critical for eye-specific refinement and instead, normal activity levels are permissive for retinogeniculate development. Here we revisit the effects of ablating the cholinergic network during eye-specific segregation and show that SAC ablation disrupts, but does not eliminate, retinal waves with no concomitant impact on normal eye-specific segregation in the dLGN. We induced SAC ablation in postnatal ferret pups beginning at birth by intraocular injection of a novel immunotoxin selective for the ferret vesicular acetylcholine transporter (Ferret VAChT-Sap). Through dual-patch whole-cell and multi-electrode array recording we found that SAC ablation altered SRA patterns and led to significantly smaller retinal waves compared with controls. Despite these defects, eye-specific segregation was normal. Further, interocular competition for target territory in the dLGN proceeded in cases where SAC ablation was asymmetric in the two eyes. Our data demonstrate normal eye-specific retinogeniculate development despite significant abnormalities in patterned SRA. Comparing our current results with earlier studies suggests that defects in retinal wave size, absolute levels of SRA, correlations between RGC pairs, RGC burst frequency, high frequency RGC firing during bursts, and the number of spikes per RGC burst are each uncorrelated with abnormalities in eye-specific segregation in the dLGN. An increase in the fraction of asynchronous spikes occurring outside of bursts and waves correlates with eye-specific segregation defects in studies reported to date. These findings highlight the relative importance of different features of SRA while providing additional constraints for computational models of Hebbian plasticity mechanisms in the developing visual system.

Fundus autofluorescence patterns in primary intraocular lymphoma.

PubMed

Casady, Megan; Faia, Lisa; Nazemzadeh, Maryam; Nussenblatt, Robert; Chan, Chi-Chao; Sen, H Nida

2014-02-01

To evaluate fundus autofluorescence (FAF) patterns in patients with primary intraocular (vitreoretinal) lymphoma. Records of all patients with primary intraocular lymphoma who underwent FAF imaging at the National Eye Institute were reviewed. Fundus autofluorescence patterns were evaluated with respect to clinical disease status and the findings on fluorescein angiography and spectral-domain optical coherence tomography. There were 18 eyes (10 patients) with primary intraocular lymphoma that underwent FAF imaging. Abnormal autofluorescence in the form of granular hyperautofluorescence and hypoautofluorescence was seen in 11 eyes (61%), and blockage by mass lesion was seen in 2 eyes (11%). All eyes with granular pattern on FAF had active primary intraocular lymphoma at the time of imaging, but there were 5 eyes with unremarkable FAF, which were found to have active lymphoma. The most common pattern on fluorescein angiography was hypofluorescent round spots with a "leopard spot" appearance (43%). These hypofluorescent spots on fluorescein angiography correlated with hyperautofluorescent spots on FAF in 5 eyes (36%) (inversion of FAF). Nodular hyperreflective spots at the level of retinal pigment epithelium on optical coherence tomography were noted in 43% of eyes. The hyperautofluorescent spots on FAF correlated with nodular hyperreflective spots on optical coherence tomography in 6 eyes (43%). Granularity on FAF was associated with active lymphoma in majority of the cases. An inversion of FAF (hyperautofluorescent spots on FAF corresponding to hypofluorescent spots on fluorescein angiography) was observed in less than half of the eyes.

MAPK Target Sites of Eyes Absent Are Not Required for Eye Development or Survival in Drosophila

PubMed Central

Jusiak, Barbara; Abulimiti, Abuduaini; Haelterman, Nele; Chen, Rui; Mardon, Graeme

2012-01-01

Eyes absent (Eya) is a highly conserved transcription cofactor and protein phosphatase that plays an essential role in eye development and survival in Drosophila. Ectopic eye induction assays using cDNA transgenes have suggested that mitogen activated protein kinase (MAPK) activates Eya by phosphorylating it on two consensus target sites, S402 and S407, and that this activation potentiates the ability of Eya to drive eye formation. However, this mechanism has never been tested in normal eye development. In the current study, we generated a series of genomic rescue transgenes to investigate how loss- and gain-of-function mutations at these two MAPK target sites within Eya affect Drosophila survival and normal eye formation: eya+GR, the wild-type control; eyaSAGR, which lacks phosphorylation at the two target residues; and eyaSDEGR, which contains phosphomimetic amino acids at the same two residues. Contrary to the previous studies in ectopic eye development, all eya genomic transgenes tested rescue both eye formation and survival equally effectively. We conclude that, in contrast to ectopic eye formation, MAPK-mediated phosphorylation of Eya on S402 and S407 does not play a role in normal development. This is the first study in Drosophila to evaluate the difference in outcomes between genomic rescue and ectopic cDNA-based overexpression of the same gene. These findings indicate similar genomic rescue strategies may prove useful for re-evaluating other long-standing Drosophila developmental models. PMID:23251383

Development of Methods for the Real-Time and Rapid Identification and Detection of TSE in Living Animals Using Fluorescence Spectroscopy of the Eye

DTIC Science & Technology

2007-07-01

retina . Our experiments have so far been limited to sheep. Our experiments have been designed to address the following questions: 1. Can ocular spectra...components and reports that the cornea, lens, retina , and optic nerve show promise. Of these, the optic nerve showed the most potential for changes in...investigations so far suggest that the most promising part of the eye for revealing spectroscopic signatures of neurological disease is the retina . Our

Safety Harness For Work Under Suspended Load

NASA Technical Reports Server (NTRS)

Sunoo, Su Young

1994-01-01

Safety device protects worker under suspended engine or other heavy load. Mechanically linked with load so if load should fall, worker yanked safely away. Worker wears chest-plate vest with straps crossing eye on back. Lower safety cable connected to eye extends horizontally away from worker to nearby wall, wrapped on pulley and extends upward to motion amplifier or reducer. Safety cables transform any sudden downward motion of overhanging load into rapid sideways motion of worker. Net catches worker, preventing worker from bumping against wall.

C-H oxidation and chelation of a dipyrromethane mediated rapid colorimetric naked-eye Cu(ii) chemosensor.

PubMed

Rajmohan, Rajamani; Ayaz Ahmed, Khan Behlol; Sangeetha, Sampathkumar; Anbazhagan, Veerappan; Vairaprakash, Pothiappan

2017-09-08

Copper(ii) ion mediated C-H oxidation of dipyrromethanes (DPMs) to the corresponding dipyrrins followed by complexation invoked the selective sensing of copper(ii) ions in aqueous solutions. On the addition of copper, the colour of the DPM solution instantaneously changes from yellow to pink with the detection limit of 0.104 μM measured by absorption spectroscopy, whereas visible colour changes could be observed by the naked eye for concentrations as low as 3 μM.

Vertical eye position-dependence of the human vestibuloocular reflex during passive and active yaw head rotations.

PubMed

Thurtell, M J; Black, R A; Halmagyi, G M; Curthoys, I S; Aw, S T

1999-05-01

Vertical eye position-dependence of the human vestibuloocular reflex during passive and active yaw head rotations. The effect of vertical eye-in-head position on the compensatory eye rotation response to passive and active high acceleration yaw head rotations was examined in eight normal human subjects. The stimuli consisted of brief, low amplitude (15-25 degrees ), high acceleration (4,000-6,000 degrees /s2) yaw head rotations with respect to the trunk (peak velocity was 150-350 degrees /s). Eye and head rotations were recorded in three-dimensional space using the magnetic search coil technique. The input-output kinematics of the three-dimensional vestibuloocular reflex (VOR) were assessed by finding the difference between the inverted eye velocity vector and the head velocity vector (both referenced to a head-fixed coordinate system) as a time series. During passive head impulses, the head and eye velocity axes aligned well with each other for the first 47 ms after the onset of the stimulus, regardless of vertical eye-in-head position. After the initial 47-ms period, the degree of alignment of the eye and head velocity axes was modulated by vertical eye-in-head position. When fixation was on a target 20 degrees up, the eye and head velocity axes remained well aligned with each other. However, when fixation was on targets at 0 and 20 degrees down, the eye velocity axis tilted forward relative to the head velocity axis. During active head impulses, the axis tilt became apparent within 5 ms of the onset of the stimulus. When fixation was on a target at 0 degrees, the velocity axes remained well aligned with each other. When fixation was on a target 20 degrees up, the eye velocity axis tilted backward, when fixation was on a target 20 degrees down, the eye velocity axis tilted forward. The findings show that the VOR compensates very well for head motion in the early part of the response to unpredictable high acceleration stimuli-the eye position- dependence of the VOR does not become apparent until 47 ms after the onset of the stimulus. In contrast, the response to active high acceleration stimuli shows eye position-dependence from within 5 ms of the onset of the stimulus. A model using a VOR-Listing's law compromise strategy did not accurately predict the patterns observed in the data, raising questions about how the eye position-dependence of the VOR is generated. We suggest, in view of recent findings, that the phenomenon could arise due to the effects of fibromuscular pulleys on the functional pulling directions of the rectus muscles.

Hyperthyroid vs hypothyroid eye disease: the same severity and activity

PubMed Central

Kashkouli, M B; Pakdel, F; Kiavash, V; Heidari, I; Heirati, A; Jam, S

2011-01-01

Purpose To compare demographics, severity, and activity of thyroid eye disease (TED) in patients with hyperthyroidism (Hr-TED) vs primary hypothyroidism (Ho-TED). Patients and Methods In a cross-sectional study, demographics, complete eye examination, severity score (NOSPECS, total hundred eye score), clinical activity score, and Rundle grading were recorded for patients with TED and different thyroid disorders referred from an endocrinology clinic from 2003 to 2006. Results TED was clinically found in 303 patients (303/851, 35.6%). The majority of them (280/303, 92.4%) had Graves' hyperthyroidism and 23 (23/303, 7.5%) had primary hypothyroidism. Mean age, gender, mean severity score, mean activity score, Rundle grade, unilateral presentation of TED, smoking habit, mean duration of eye disease, and mean interval time of thyroid to TED were not significantly different between the two groups (0.06

Impacts of SST Patterns on Rapid Intensification of Typhoon Megi (2010)

NASA Astrophysics Data System (ADS)

Kanada, Sachie; Tsujino, Satoki; Aiki, Hidenori; Yoshioka, Mayumi K.; Miyazawa, Yasumasa; Tsuboki, Kazuhisa; Takayabu, Izuru

2017-12-01

Typhoon Megi (2010), a very intense tropical cyclone with a minimum central pressure of 885 hPa, was characterized by especially rapid intensification. We investigated this intensification process by a simulation experiment using a high-resolution (0.02° × 0.02°) three-dimensional atmosphere-ocean coupled regional model. We also performed a sensitivity experiment with a time-fixed sea surface temperature (SST). The coupled model successfully simulated the minimum central pressure of Typhoon Megi, whereas the fixed SST experiment simulated an excessively low minimum central pressure of 839 hPa. The simulation results also showed a close relationship between the radial SST profiles and the rapid intensification process. Because the warm sea increased near-surface water vapor and hence the convective available potential energy, the high SST in the eye region facilitated tall and intense updrafts inside the radius of maximum wind speed and led to the start of rapid intensification. In contrast, high SST outside this radius induced local secondary updrafts that inhibited rapid intensification even if the mean SST in the core region exceeded 29.0°C. These secondary updrafts moved inward and eventually merged with the primary eyewall updrafts. Then the storm intensified rapidly when the high SST appeared in the eye region. Thus, the changes in the local SST pattern around the storm center strongly affected the rapid intensification process by modulating the radial structure of core convection. Our results also show that the use of a high-resolution three-dimensional atmosphere-ocean coupled model offers promise for improving intensity forecasts of tropical cyclones.

No short-term effects of digital mobile radio telephone on the awake human electroencephalogram

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roeschke, J.; Mann, K.

1997-05-01

A recent study reported the results of an exploratory study of alterations of the quantitative sleep profile due to the effects of a digital mobile radio telephone. Rapid eye movement (REM) was suppressed, and the spectral power density in the 8--13 Hz frequency range during REM sleep was altered. The aim of the present study was to illuminate the influence of digital mobile radio telephone on the awake electroencephalogram (EEG) of healthy subjects. For this purpose, the authors investigated 34 male subjects in a single-blind cross-over design experiment by measuring spontaneous EEGs under closed-eyes condition from scalp positions C{sub 3}more » and C{sub 4} and comparing the effects of an active and an inactive digital mobile radio telephone (GSM) system. During exposure of nearly 3.5 min to the 900 MHz electromagnetic field pulsed at a frequency of 217 Hz and with a pulse width of 580 {micro}s, the authors could not detect any difference in the awake EEGs in terms of spectral power density measures.« less

Maize Cropping Systems Mapping Using RapidEye Observations in Agro-Ecological Landscapes in Kenya.

PubMed

Richard, Kyalo; Abdel-Rahman, Elfatih M; Subramanian, Sevgan; Nyasani, Johnson O; Thiel, Michael; Jozani, Hosein; Borgemeister, Christian; Landmann, Tobias

2017-11-03

Cropping systems information on explicit scales is an important but rarely available variable in many crops modeling routines and of utmost importance for understanding pests and disease propagation mechanisms in agro-ecological landscapes. In this study, high spatial and temporal resolution RapidEye bio-temporal data were utilized within a novel 2-step hierarchical random forest (RF) classification approach to map areas of mono- and mixed maize cropping systems. A small-scale maize farming site in Machakos County, Kenya was used as a study site. Within the study site, field data was collected during the satellite acquisition period on general land use/land cover (LULC) and the two cropping systems. Firstly, non-cropland areas were masked out from other land use/land cover using the LULC mapping result. Subsequently an optimized RF model was applied to the cropland layer to map the two cropping systems (2nd classification step). An overall accuracy of 93% was attained for the LULC classification, while the class accuracies (PA: producer's accuracy and UA: user's accuracy) for the two cropping systems were consistently above 85%. We concluded that explicit mapping of different cropping systems is feasible in complex and highly fragmented agro-ecological landscapes if high resolution and multi-temporal satellite data such as 5 m RapidEye data is employed. Further research is needed on the feasibility of using freely available 10-20 m Sentinel-2 data for wide-area assessment of cropping systems as an important variable in numerous crop productivity models.

Sleep-wake patterns, non-rapid eye movement, and rapid eye movement sleep cycles in teenage narcolepsy.

PubMed

Xu, Xing; Wu, Huijuan; Zhuang, Jianhua; Chen, Kun; Huang, Bei; Zhao, Zhengqing; Zhao, Zhongxin

2017-05-01

To further characterize sleep disorders associated with narcolepsy, we assessed the sleep-wake patterns, rapid eye movement (REM), and non-REM (NREM) sleep cycles in Chinese teenagers with narcolepsy. A total of 14 Chinese type 1 narcoleptic patients (13.4 ± 2.6 years of age) and 14 healthy age- and sex-matched control subjects (13.6 ± 1.8 years of age) were recruited. Ambulatory 24-h polysomnography was recorded for two days, with test subjects adapting to the instruments on day one and the study data collection performed on day two. Compared with the controls, the narcoleptic patients showed a 1.5-fold increase in total sleep time over 24 h, characterized by enhanced slow-wave sleep and REM sleep. Frequent sleep-wake transitions were identified in nocturnal sleep with all sleep stages switching to wakefulness, with more awakenings and time spent in wakefulness after sleep onset. Despite eight cases of narcolepsy with sleep onset REM periods at night, the mean duration of NREM-REM sleep cycle episode and the ratio of REM/NREM sleep between patients and controls were not significantly different. Our study identified hypersomnia in teenage narcolepsy despite excessive daytime sleepiness. Sleep fragmentation extended to all sleep stages, indicating impaired sleep-wake cycles and instability of sleep stages. The limited effects on NREM-REM sleep cycles suggest the relative conservation of ultradian regulation of sleep. Copyright © 2016 Elsevier B.V. All rights reserved.

Decreased cortical activation in response to a motion stimulus in anisometropic amblyopic eyes using functional magnetic resonance imaging.

PubMed

Bonhomme, Gabrielle R; Liu, Grant T; Miki, Atsushi; Francis, Ellie; Dobre, M-C; Modestino, Edward J; Aleman, David O; Haselgrove, John C

2006-12-01

Motion perception abnormalities and extrastriate abnormalities have been suggested in amblyopia. Functional MRI (fMRI) and motion stimuli were used to study whether interocular differences in activation are detectable in motion-sensitive cortical areas in patients with anisometropic amblyopia. We performed fMRI at 1.5 T 4 control subjects (20/20 OU), 1 with monocular suppression (20/25), and 2 with anisometropic amblyopia (20/60, 20/800). Monocular suppression was thought to be form fruste of amblyopia. The experimental stimulus consisted of expanding and contracting concentric rings, whereas the control condition consisted of stationary concentric rings. Activation was determined by contrasting the 2 conditions for each eye. Significant fMRI activation and comparable right and left eye activation was found in V3a and V5 in all control subjects (Average z-values in L vs R contrast 0.42, 0.43) and in the subject with monocular suppression (z = 0.19). The anisometropes exhibited decreased extrastriate activation in their amblyopic eyes compared with the fellow eyes (zs = 2.12, 2.76). Our data suggest motion-sensitive cortical structures may be less active when anisometropic amblyopic eyes are stimulated with moving rings. These results support the hypothesis that extrastriate cortex is affected in anisometropic amblyopia. Although suggestive of a magnocellular defect, the exact mechanism is unclear.

Bumetanide for autism: more eye contact, less amygdala activation.

PubMed

Hadjikhani, Nouchine; Åsberg Johnels, Jakob; Lassalle, Amandine; Zürcher, Nicole R; Hippolyte, Loyse; Gillberg, Christopher; Lemonnier, Eric; Ben-Ari, Yehezkel

2018-02-26

We recently showed that constraining eye contact leads to exaggerated increase of amygdala activation in autism. Here, in a proof of concept pilot study, we demonstrate that administration of bumetanide (a NKCC1 chloride importer antagonist that restores GABAergic inhibition) normalizes the level of amygdala activation during constrained eye contact with dynamic emotional face stimuli in autism. In addition, eye-tracking data reveal that bumetanide administration increases the time spent in spontaneous eye gaze during in a free-viewing mode of the same face stimuli. In keeping with clinical trials, our data support the Excitatory/Inhibitory dysfunction hypothesis in autism, and indicate that bumetanide may improve specific aspects of social processing in autism. Future double-blind placebo controlled studies with larger cohorts of participants will help clarify the mechanisms of bumetanide action in autism.

Eye movement training is most effective when it involves a task-relevant sensorimotor decision.

PubMed

Fooken, Jolande; Lalonde, Kathryn M; Mann, Gurkiran K; Spering, Miriam

2018-04-01

Eye and hand movements are closely linked when performing everyday actions. We conducted a perceptual-motor training study to investigate mutually beneficial effects of eye and hand movements, asking whether training in one modality benefits performance in the other. Observers had to predict the future trajectory of a briefly presented moving object, and intercept it at its assumed location as accurately as possible with their finger. Eye and hand movements were recorded simultaneously. Different training protocols either included eye movements or a combination of eye and hand movements with or without external performance feedback. Eye movement training did not transfer across modalities: Irrespective of feedback, finger interception accuracy and precision improved after training that involved the hand, but not after isolated eye movement training. Conversely, eye movements benefited from hand movement training or when external performance feedback was given, thus improving only when an active interceptive task component was involved. These findings indicate only limited transfer across modalities. However, they reveal the importance of creating a training task with an active sensorimotor decision to improve the accuracy and precision of eye and hand movements.

Truly simultaneous SS-OCT of the anterior and posterior human eye with full anterior chamber and 50° retinal field of views (Conference Presentation)

NASA Astrophysics Data System (ADS)

McNabb, Ryan P.; Viehland, Christian; Keller, Brenton; Vann, Robin R.; Izatt, Joseph A.; Kuo, Anthony N.

2017-02-01

Optical coherence tomography (OCT) has revolutionized clinical observation of the eye and is an indispensable part of the modern ophthalmic practice. Unlike many other ophthalmic imaging techniques, OCT provides three-dimensional information about the imaged eye. However, conventional clinical OCT systems image only the anterior or the posterior eye during a single acquisition. Newer OCT systems have begun to image both during the same acquisition but with compromises such as limited field of view in the posterior eye or requiring rapid switching between the anterior and posterior eye during the scan. We describe here the development and demonstration of an OCT system with truly simultaneous imaging of both the anterior and posterior eye capable of imaging the full anterior chamber width and 50° on the retina (macula, optic nerve, and arcades). The whole eye OCT system was developed using custom optics and optomechanics. Polarization was utilized to separate the imaging channels. We utilized a 200kHz swept-source laser (Axsun Technologies) centered at 1040±50nm of bandwidth. The clock signal generated by the laser was interpolated 4x to generate 5504 samples per laser sweep. With the whole eye OCT system, we simultaneously acquired anterior and posterior segments with repeated B-scans as well as three-dimensional volumes from seven healthy volunteers (other than refractive error). On three of these volunteers, whole eye OCT and partial coherence interferometry (LenStar PCI, Haag-Streit) were used to measure axial eye length. We measured a mean repeatability of ±47µm with whole eye OCT and a mean difference from PCI of -68µm.

Eye position modulates the electromyographic responses of neck muscles to electrical stimulation of the superior colliculus in the alert cat.

PubMed

Hadjidimitrakis, K; Moschovakis, A K; Dalezios, Y; Grantyn, A

2007-05-01

Rapid gaze shifts are often accomplished with coordinated movements of the eyes and head, the relative amplitude of which depends on the starting position of the eyes. The size of gaze shifts is determined by the superior colliculus (SC) but additional processing in the lower brain stem is needed to determine the relative contributions of eye and head components. Models of eye-head coordination often assume that the strength of the command sent to the head controllers is modified by a signal indicative of the eye position. Evidence in favor of this hypothesis has been recently obtained in a study of phasic electromyographic (EMG) responses to stimulation of the SC in head-restrained monkeys (Corneil et al. in J Neurophysiol 88:2000-2018, 2002b). Bearing in mind that the patterns of eye-head coordination are not the same in all species and because the eye position sensitivity of phasic EMG responses has not been systematically investigated in cats, in the present study we used cats to address this issue. We stimulated electrically the intermediate and deep layers of the caudal SC in alert cats and recorded the EMG responses of neck muscles with horizontal and vertical pulling directions. Our data demonstrate that phasic, short latency EMG responses can be modulated by the eye position such that they increase as the eye occupies more and more eccentric positions in the pulling direction of the muscle tested. However, the influence of the eye position is rather modest, typically accounting for only 10-50% of the variance of EMG response amplitude. Responses evoked from several SC sites were not modulated by the eye position.

Partial preservation of rod and cone ERG function following subretinal injection of ARPE-19 cells in RCS rats.

PubMed

Sauvé, Y; Pinilla, I; Lund, R D

2006-04-01

We quantified rod- and cone-related electroretinogram (ERG) responses following subretinal injections of the human-derived retinal pigment epithelial (hRPE) cell line ARPE-19 at age P23 to prevent progressive photoreceptor loss in the Royal College of Surgeons (RCS) rat. Culture medium-injected eyes served as sham controls. At P60, in comparison with sham-injected eyes, all recordings from hRPE-injected eyes showed preserved scotopic a- and b-waves, oscillatory potentials, double-flash-derived rod b-waves and photopic cone b-waves, and flicker critical fusion frequencies and amplitudes. Although the actual preservation did not exceed 10% of a-wave and 20% of b-wave amplitude values in non-dystrophic RCS and deteriorated rapidly by P90, rod- and cone-related ERG parameters were still recordable up to P120 unlike the virtually unresponsive sham-injected eyes.

Intersegmental Eye-Head-Body Interactions during Complex Whole Body Movements

PubMed Central

von Laßberg, Christoph; Beykirch, Karl A.; Mohler, Betty J.; Bülthoff, Heinrich H.

2014-01-01

Using state-of-the-art technology, interactions of eye, head and intersegmental body movements were analyzed for the first time during multiple twisting somersaults of high-level gymnasts. With this aim, we used a unique combination of a 16-channel infrared kinemetric system; a three-dimensional video kinemetric system; wireless electromyography; and a specialized wireless sport-video-oculography system, which was able to capture and calculate precise oculomotor data under conditions of rapid multiaxial acceleration. All data were synchronized and integrated in a multimodal software tool for three-dimensional analysis. During specific phases of the recorded movements, a previously unknown eye-head-body interaction was observed. The phenomenon was marked by a prolonged and complete suppression of gaze-stabilizing eye movements, in favor of a tight coupling with the head, spine and joint movements of the gymnasts. Potential reasons for these observations are discussed with regard to earlier findings and integrated within a functional model. PMID:24763143

Radiation retinopathy: case report and review.

PubMed

Gupta, Abha; Dhawahir-Scala, Felipe; Smith, Amy; Young, Lorna; Charles, Steve

2007-04-05

Ocular damage from radiation treatment is a well established phenomenon. Many factors are now known to influence the incidence of radiation retinopathy, including total dosage and daily fraction size. Patients who are diabetic, hypertensive or received previous chemotherapy are more susceptible to radiation retinopathy. A 55 year old male was referred from the oncology department with epiphora. His medical history included Type 2 Insulin treated Diabetes Mellitus and hypertension. One year prior to presentation he had undergone a total rhinectomy with a 4 week course of post-operative radiotherapy for an aggressive sqaumous cell carcinoma of the nose. On examination the visual acuity was noted to be 6/36 left eye and 6/9 right eye. Posterior segment examination revealed marked retinal ischaemia present in the posterior pole and macular region of both eyes. The appearance was not thought to be typical of diabetic changes, radiation retinopathy being the more likely diagnosis especially in view of his history. Over the next four months the vision in both eyes rapidly deteriorated to 3/60 left eye and 1/60 right eye. Bilateral pan retinal photocoagulation was thought to be appropriate treatment at this point. This case highlights the importance for ophthalmologists and oncologists to be aware of the close relationship between diabetes and radiation treatment and the profound rapid impact this combination of factors may have on visual function. Radiation is being used with increasing frequency for ocular and orbital disease, because of this more cases of radiation retinopathy may become prevalent. Factors which may potentiate radiation retinopathy should be well known including, increased radiation dosage, increased fraction size, concomitant systemic vascular disease and use of chemotherapy. Counselling should be offered in all cases at risk of visual loss. As no effective treatment currently exists to restore visual function, monitoring of visual acuity in all cases and early referral to the ophthalmologist as appropriate is warranted.

Where’s Waldo? How perceptual, cognitive, and emotional brain processes cooperate during learning to categorize and find desired objects in a cluttered scene

PubMed Central

Chang, Hung-Cheng; Grossberg, Stephen; Cao, Yongqiang

2014-01-01

The Where’s Waldo problem concerns how individuals can rapidly learn to search a scene to detect, attend, recognize, and look at a valued target object in it. This article develops the ARTSCAN Search neural model to clarify how brain mechanisms across the What and Where cortical streams are coordinated to solve the Where’s Waldo problem. The What stream learns positionally-invariant object representations, whereas the Where stream controls positionally-selective spatial and action representations. The model overcomes deficiencies of these computationally complementary properties through What and Where stream interactions. Where stream processes of spatial attention and predictive eye movement control modulate What stream processes whereby multiple view- and positionally-specific object categories are learned and associatively linked to view- and positionally-invariant object categories through bottom-up and attentive top-down interactions. Gain fields control the coordinate transformations that enable spatial attention and predictive eye movements to carry out this role. What stream cognitive-emotional learning processes enable the focusing of motivated attention upon the invariant object categories of desired objects. What stream cognitive names or motivational drives can prime a view- and positionally-invariant object category of a desired target object. A volitional signal can convert these primes into top-down activations that can, in turn, prime What stream view- and positionally-specific categories. When it also receives bottom-up activation from a target, such a positionally-specific category can cause an attentional shift in the Where stream to the positional representation of the target, and an eye movement can then be elicited to foveate it. These processes describe interactions among brain regions that include visual cortex, parietal cortex, inferotemporal cortex, prefrontal cortex (PFC), amygdala, basal ganglia (BG), and superior colliculus (SC). PMID:24987339

The Clinical Phenotype of Idiopathic Rapid Eye Movement Sleep Behavior Disorder at Presentation: A Study in 203 Consecutive Patients

PubMed Central

Fernández-Arcos, Ana; Iranzo, Alex; Serradell, Mónica; Gaig, Carles; Santamaria, Joan

2016-01-01

Objective: To describe the clinical phenotype of idiopathic rapid eye movement (REM) sleep behavior disorder (IRBD) at presentation in a sleep center. Methods: Clinical history review of 203 consecutive patients with IRBD identified between 1990 and 2014. IRBD was diagnosed by clinical history plus video-polysomnographic demonstration of REM sleep with increased electromyographic activity linked to abnormal behaviors. Results: Patients were 80% men with median age at IRBD diagnosis of 68 y (range, 50–85 y). In addition to the already known clinical picture of IRBD, other important features were apparent: 44% of the patients were not aware of their dream-enactment behaviors and 70% reported good sleep quality. In most of these cases bed partners were essential to convince patients to seek medical help. In 11% IRBD was elicited only after specific questioning when patients consulted for other reasons. Seven percent did not recall unpleasant dreams. Leaving the bed occurred occasionally in 24% of subjects in whom dementia with Lewy bodies often developed eventually. For the correct diagnosis of IRBD, video-polysomnography had to be repeated in 16% because of insufficient REM sleep or electromyographic artifacts from coexistent apneas. Some subjects with comorbid obstructive sleep apnea reported partial improvement of RBD symptoms following continuous positive airway pressure therapy. Lack of therapy with clonazepam resulted in an increased risk of sleep related injuries. Synucleinopathy was frequently diagnosed, even in patients with mild severity or uncommon IRBD presentations (e.g., patients who reported sleeping well, onset triggered by a life event, nocturnal ambulation) indicating that the development of a neurodegenerative disease is independent of the clinical presentation of IRBD. Conclusions: We report the largest IRBD cohort observed in a single center to date and highlight frequent features that were not reported or not sufficiently emphasized in previous publications. Physicians should be aware of the full clinical expression of IRBD, a sleep disturbance that represents a neurodegenerative disease. Commentary: A commentary on this article appears in this issue on page 7. Citation: Fernández-Arcos A, Iranzo A, Serradell M, Gaig C, Santamaria J. The clinical phenotype of idiopathic rapid eye movement sleep behavior disorder at presentation: a study in 203 consecutive patients. SLEEP 2016;39(1):121–132. PMID:26940460

Chronic escitalopram treatment attenuated the accelerated rapid eye movement sleep transitions after selective rapid eye movement sleep deprivation: a model-based analysis using Markov chains.

PubMed

Kostyalik, Diána; Vas, Szilvia; Kátai, Zita; Kitka, Tamás; Gyertyán, István; Bagdy, Gyorgy; Tóthfalusi, László

2014-11-19

Shortened rapid eye movement (REM) sleep latency and increased REM sleep amount are presumed biological markers of depression. These sleep alterations are also observable in several animal models of depression as well as during the rebound sleep after selective REM sleep deprivation (RD). Furthermore, REM sleep fragmentation is typically associated with stress procedures and anxiety. The selective serotonin reuptake inhibitor (SSRI) antidepressants reduce REM sleep time and increase REM latency after acute dosing in normal condition and even during REM rebound following RD. However, their therapeutic outcome evolves only after weeks of treatment, and the effects of chronic treatment in REM-deprived animals have not been studied yet. Chronic escitalopram- (10 mg/kg/day, osmotic minipump for 24 days) or vehicle-treated rats were subjected to a 3-day-long RD on day 21 using the flower pot procedure or kept in home cage. On day 24, fronto-parietal electroencephalogram, electromyogram and motility were recorded in the first 2 h of the passive phase. The observed sleep patterns were characterized applying standard sleep metrics, by modelling the transitions between sleep phases using Markov chains and by spectral analysis. Based on Markov chain analysis, chronic escitalopram treatment attenuated the REM sleep fragmentation [accelerated transition rates between REM and non-REM (NREM) stages, decreased REM sleep residence time between two transitions] during the rebound sleep. Additionally, the antidepressant avoided the frequent awakenings during the first 30 min of recovery period. The spectral analysis showed that the SSRI prevented the RD-caused elevation in theta (5-9 Hz) power during slow-wave sleep. Conversely, based on the aggregate sleep metrics, escitalopram had only moderate effects and it did not significantly attenuate the REM rebound after RD. In conclusion, chronic SSRI treatment is capable of reducing several effects on sleep which might be the consequence of the sub-chronic stress caused by the flower pot method. These data might support the antidepressant activity of SSRIs, and may allude that investigating the rebound period following the flower pot protocol could be useful to detect antidepressant drug response. Markov analysis is a suitable method to study the sleep pattern.

Effects of preincubation of eggs and activation medium on the percentage of eyed embryos in ide (Leuciscus idus), an externally fertilizing fish.

PubMed

Siddique, Mohammad Abdul Momin; Linhart, Otomar; Krejszeff, Sławomir; Żarski, Daniel; Król, Jarosław; Butts, Ian Anthony Ernest

2016-03-15

Standardization of fertilization protocols is crucial for improving reproductive techniques for externally fertilizing fish in captive breeding. Therefore, the objectives of this study were to determine the effects of preincubation of eggs and activation medium on the percentage of eyed embryos for ide (Leuciscus idus). Pooled eggs from five females were preincubated in three different activating media for 0, 30, 60, 90, and 120 seconds and then fertilized by pooled sperm from five males. At the eyed-egg stage, the percentage of viable embryos was later calculated. Results showed that preincubation time was significant for the freshwater activation medium (P < 0.001), such that the percentage of eyed embryos declined across the preincubation time gradient. Additionally, there was an effect on the percentage of eyed embryos when eggs were incubated with Woynarovich solution (P < 0.001), such that a decline was detected at 90 seconds, whereas no effect was detected for the saline water medium. Activating medium had a significant effect on the percentage of eyed embryos for each preincubation time (P < 0.05). More precisely, freshwater produced the lowest percentage of eyed embryos at all preincubation times (ranged from 1.9% at 120 seconds to 43.6% at 0 seconds), whereas saline water and Woynarovich solution produced the highest percentage of eyed embryos at 0 seconds and 30 seconds before incubation. Woynarovich solution produced the highest percentage of eyed embryos at 60 seconds (65.26%), whereas saline water produced the highest percentage at 90 seconds (68.37%). No difference was detected between saline water and Woynarovich solution at 120 seconds. Examination of sperm traits showed no impact of activating medium on computer assisted sperm analysis parameters. Together, these results suggest that saline water or Woynarovich solution improve fertilization rate in ide during IVF; thus, these media are useful for standardizing fertilization protocols and controlled reproduction for this species. Copyright © 2016 Elsevier Inc. All rights reserved.

The Dorsal Visual System Predicts Future and Remembers Past Eye Position

PubMed Central

Morris, Adam P.; Bremmer, Frank; Krekelberg, Bart

2016-01-01

Eye movements are essential to primate vision but introduce potentially disruptive displacements of the retinal image. To maintain stable vision, the brain is thought to rely on neurons that carry both visual signals and information about the current direction of gaze in their firing rates. We have shown previously that these neurons provide an accurate representation of eye position during fixation, but whether they are updated fast enough during saccadic eye movements to support real-time vision remains controversial. Here we show that not only do these neurons carry a fast and accurate eye-position signal, but also that they support in parallel a range of time-lagged variants, including predictive and post dictive signals. We recorded extracellular activity in four areas of the macaque dorsal visual cortex during a saccade task, including the lateral and ventral intraparietal areas (LIP, VIP), and the middle temporal (MT) and medial superior temporal (MST) areas. As reported previously, neurons showed tonic eye-position-related activity during fixation. In addition, they showed a variety of transient changes in activity around the time of saccades, including relative suppression, enhancement, and pre-saccadic bursts for one saccade direction over another. We show that a hypothetical neuron that pools this rich population activity through a weighted sum can produce an output that mimics the true spatiotemporal dynamics of the eye. Further, with different pooling weights, this downstream eye position signal (EPS) could be updated long before (<100 ms) or after (<200 ms) an eye movement. The results suggest a flexible coding scheme in which downstream computations have access to past, current, and future eye positions simultaneously, providing a basis for visual stability and delay-free visually-guided behavior. PMID:26941617

Changes in shape and astigmatism of total, anterior, and posterior cornea after long versus short clear corneal incision cataract surgery.

PubMed

Hayashi, Ken; Yoshida, Motoaki; Hirata, Akira; Yoshimura, Koichi

2018-01-01

To compare changes in the shape and astigmatism of the total, anterior, and posterior cornea between eyes with long-length clear corneal incisions (CCIs) and eyes with short-length CCIs in cataract surgery. Hayashi Eye Hospital, Fukuoka, Japan. Prospective case series. Both eyes of patients having phacoemulsification with temporal CCIs were randomized to have a long-length (≥1.75 mm) or short-length (<1.75 mm) CCI. Corneal astigmatic changes were decomposed to vertical/horizontal (Jackson cross-cylinder, axes at 180 degrees and 90 degrees [J0]) and oblique changes (Jackson cross-cylinder, axes at 45 degrees and 135 degrees [J45]) using power vector analysis. Corneal shape changes were assessed using the average of the difference map on videokeratography 2 days and 2, 4, and 8 weeks postoperatively. The mean J0 and J45 values of the total cornea in the 120 eyes evaluated were significantly greater in the long CCI group than in the short CCI group at all follow-ups (P ≤ .0290). The videokeratography showed a wedge-shaped flattening in the total and anterior cornea and a steepening in the posterior cornea around the CCI 2 days postoperatively in both groups. This wound-related flattening of the total and anterior cornea rapidly reduced but persisted until 8 weeks, whereas the steepening of the posterior cornea disappeared within 4 weeks. These changes extended closer to the central cornea in the long CCI group than in the short CCI group. Corneal astigmatic changes were significantly greater after long CCI than after short CCI. The wound-related shape changes occurred immediately postoperatively but rapidly diminished. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Design of "Eye Closure" system for the stealth of photo-electric equipments

NASA Astrophysics Data System (ADS)

Zhang, Y.; Hua, W. S.; Li, G.

2012-10-01

Based on the optical activity of liquid crystal, a new approach for the stealth of "cat's eye" targets is proposed in this paper. It imitates the physiological close reaction of human eyes when strong light irradiates eyes. With this approach, the "cat's eye" effect will vanish, which is applied in restricting photo-electric equipments being detected and located by active laser detection system. The structure and working principle of the design are presented. The drive circuit is given to control the optical switch automatically. Feasibility of this design is demonstrated by experimental method. The measured data illustrate that the proposed approach is effective to eliminate the "cat's eye" effect, so as to enhancing the viability of photo-electric equipments on the battlefield.

The anatomical relationships between the avian eye, orbit and sclerotic ring: implications for inferring activity patterns in extinct birds

PubMed Central

Hall, Margaret I

2008-01-01

Activity pattern, or the time of day when an animal is awake and active, is highly associated with that animal's ecology. There are two principal activity patterns: diurnal, or awake during the day in a photopic, or high light level, environment; and nocturnal, awake at night in scotopic, or low light level, conditions. Nocturnal and diurnal birds exhibit characteristic eye shapes associated with their activity pattern, with nocturnal bird eyes optimized for visual sensitivity with large corneal diameters relative to their eye axial lengths, and diurnal birds optimized for visual acuity, with larger axial lengths of the eye relative to their corneal diameters. The current study had three aims: (1) to quantify the nature of the relationship between the avian eye and its associated bony anatomy, the orbit and the sclerotic ring; (2) to investigate how activity pattern is reflected in that bony anatomy; and (3) to identify how much bony anatomy is required to interpret activity pattern reliably for a bird that does not have the soft tissue available for study, specifically, for a fossil. Knowledge of extinct avian activity patterns would be useful in making palaeoecological interpretations. Here eye, orbit and sclerotic ring morphologies of 140 nocturnal and diurnal bird species are analysed in a phylogenetic context. Although there is a close relationship between the avian eye and orbit, activity pattern can only be reliably interpreted for bony-only specimens, such as a fossil, that include both measurements of the sclerotic ring and orbit depth. Any missing data render the fossil analysis inaccurate, including fossil specimens that are flat and therefore do not have an orbit depth available. For example, activity pattern cannot be determined with confidence for Archaeopteryx lithographica, which has a complete sclerotic ring but no orbit depth measurement. Many of the bird fossils currently available that retain a good sclerotic ring tend to be flat specimens, while three-dimensionally preserved bird fossils tend not to have a well-preserved sclerotic ring or a well-defined optic foramen, necessary for delimiting the orbit depth. PMID:18510506

Choroidal and scleral mechanisms of compensation for spectacle lenses in chicks.

PubMed

Wildsoet, C; Wallman, J

1995-05-01

It is known that when hyperopic or myopic defocus is imposed on chick eyes by spectacle lenses, they rapidly compensate, becoming myopic or hyperopic respectively, by altering the depth of their vitreous chamber. Changes in two components--ocular length and choroidal thickness--underlie this rapid compensation. With monocular lens treatment, hyperopic defocus imposed by negative lenses resulted in substantially increased ocular elongation and a slight thinning of the choroid, both changes resulting in myopia; myopic defocus imposed by positive lenses resulted a dramatic increase in choroidal thickness, which pushed the retina forward toward the image plane, and a slight decrease in ocular elongation, both changes resulting in hyperopia. The refractive error after 5 days of lens wear correlated well with vitreous chamber depth, which reflected the changes in both choroidal thickness and ocular length. The degree of compensation for lenses was not affected by whether the fellow eye was covered or open. Both form-deprivation myopia and lens-induced myopia declined with age in parallel, but wearing a -15 D lens produced more myopia than did form deprivation. The spectacle lenses affected the refractive error not only of the lens-wearing eye, but also, to a much lesser degree, of the untreated fellow eye. At lens removal refractive errors were opposite in sign to the lense worn, and the subsequent changes in choroidal thickness and ocular length were also opposite to those that occurred when the lenses were in place. In this situation as well, effects of the spectacle lenses on the fellow eyes were observed. Eyes with no functional afferent connection to the brain because of either prior optic nerve section or intraocular tetrodotoxin injections showed compensatory changes to imposed defocus, but these were limited to compensation for imposed myopic defocus, at least for the eyes with optic nerve section. In addition, optic nerve section, but not tetrodotoxin treatment, moved the set-point of the visual compensatory mechanism toward hyperopia. Optic nerve section prevents myopia in response to negative lenses but not to diffusers, suggesting that compensation for hyperopia requires the central nervous system.

Food Catches the Eye but Not for Everyone: A BMI–Contingent Attentional Bias in Rapid Detection of Nutriments

PubMed Central

Nummenmaa, Lauri; Hietanen, Jari K.; Calvo, Manuel G.; Hyönä, Jukka

2011-01-01

An organism's survival depends crucially on its ability to detect and acquire nutriment. Attention circuits interact with cognitive and motivational systems to facilitate detection of salient sensory events in the environment. Here we show that the human attentional system is tuned to detect food targets among nonfood items. In two visual search experiments participants searched for discrepant food targets embedded in an array of nonfood distracters or vice versa. Detection times were faster when targets were food rather than nonfood items, and the detection advantage for food items showed a significant negative correlation with Body Mass Index (BMI). Also, eye tracking during searching within arrays of visually homogenous food and nonfood targets demonstrated that the BMI-contingent attentional bias was due to rapid capturing of the eyes by food items in individuals with low BMI. However, BMI was not associated with decision times after the discrepant food item was fixated. The results suggest that visual attention is biased towards foods, and that individual differences in energy consumption - as indexed by BMI - are associated with differential attentional effects related to foods. We speculate that such differences may constitute an important risk factor for gaining weight. PMID:21603657

Diquafosol ophthalmic solution for dry eye treatment.

PubMed

Nakamura, Masatsugu; Imanaka, Takahiro; Sakamoto, Asuka

2012-07-01

There has been rapid progress in our understanding of dry eye pathogenesis, as well as the development of improved diagnostic clinical tests. Various types of dry eye treatment drugs have been developed. This review summarizes the basic and clinical research carried out in the development of diquafosol for ophthalmic use. Diquafosol is a dinucleotide, purinoreceptor P2Y(2) receptor agonist. Basic pharmacological studies have shown that it acts on P2Y(2) receptors at the ocular surface, to promote tear and mucin secretion via elevated intracellular Ca(2+) concentrations. Diquafosol also improves tear and mucin secretion in experimental dry eye models. Based on the results of laboratory experiments, the authors conducted a series of clinical studies in patients with dry eye disease. Diquafosol was effective in the treatment of dry eye disease at an optimal dose of 3% six times a day. In comparison to commercially available 0.1% sodium hyaluronate ophthalmic solution, 3% diquafosol ophthalmic solution showed non-inferiority in improving corneal fluorescein staining scores and superiority in improving keratoconjunctival Rose Bengal staining scores. Diquafosol ophthalmic solution has a novel mechanism of action that is characterized by its stimulatory effects on tear and mucin secretion. This drug has the potential to be effective in patients with tear film instability and short break-up time type of dry eye, which are essential factors in dry eye pathogenesis.

High-speed adaptive optics line scan confocal retinal imaging for human eye.

PubMed

Lu, Jing; Gu, Boyu; Wang, Xiaolin; Zhang, Yuhua

2017-01-01

Continuous and rapid eye movement causes significant intraframe distortion in adaptive optics high resolution retinal imaging. To minimize this artifact, we developed a high speed adaptive optics line scan confocal retinal imaging system. A high speed line camera was employed to acquire retinal image and custom adaptive optics was developed to compensate the wave aberration of the human eye's optics. The spatial resolution and signal to noise ratio were assessed in model eye and in living human eye. The improvement of imaging fidelity was estimated by reduction of intra-frame distortion of retinal images acquired in the living human eyes with frame rates at 30 frames/second (FPS), 100 FPS, and 200 FPS. The device produced retinal image with cellular level resolution at 200 FPS with a digitization of 512×512 pixels/frame in the living human eye. Cone photoreceptors in the central fovea and rod photoreceptors near the fovea were resolved in three human subjects in normal chorioretinal health. Compared with retinal images acquired at 30 FPS, the intra-frame distortion in images taken at 200 FPS was reduced by 50.9% to 79.7%. We demonstrated the feasibility of acquiring high resolution retinal images in the living human eye at a speed that minimizes retinal motion artifact. This device may facilitate research involving subjects with nystagmus or unsteady fixation due to central vision loss.

Efficacy of an Amblyopia Treatment Program with Both Eyes Open: A Functional Near-Infrared Spectroscopy Study.

PubMed

Iwata, Yo; Handa, Tomoya; Ishikawa, Hitoshi; Shoji, Nobuyuki; Shimizu, Kimiya

2016-01-01

To investigate the efficacy of an amblyopia treatment program with both eyes open. Ten subjects (mean age 20.5 ± 1.5 years) were enrolled. All subjects had un-remarkable ophthalmic examinations, but several subjects had minor refractive errors. Vision function was evaluated using the 3-D visual function trainer-ORTe. Brain measurements were made using functional near-infrared spectroscopy (fNIRS) to examine the oxygenated hemoglobin (HbO 2 ) concentration change upon visual stimulus presentation. The three conditions were as follows: both eyes open and both eyes stimulated, both eyes open and only one eye stimulated, and one eye open and one eye stimulated. Changes in HbO2 between the rest and stimulation phases were not statistically different between the unilateral and bilateral stimulation conditions with both eyes open. However, HbO 2 change was significantly higher in subjects with both eyes open than in subjects with one eye closed (P < 0.001, all comparisons). Greater activation of the visual cortex is achieved when subjects are treated with both eyes open as compared to subjects with one eye occluded. From a perspective of functional brain activation, amblyopia treatment administered without occluding the healthy eye may provide the greatest therapeutic benefit. © 2016 Board of regents of the University of Wisconsin System, American Orthoptic Journal, Volume 66, 2016, ISSN 0065-955X, E-ISSN 1553-4448.

Tranexamic acid suppresses ultraviolet B eye irradiation-induced melanocyte activation by decreasing the levels of prohormone convertase 2 and alpha-melanocyte-stimulating hormone.

PubMed

Hiramoto, Keiichi; Yamate, Yurika; Sugiyama, Daijiro; Takahashi, Yumi; Mafune, Eiichi

2014-12-01

Tranexamic acid (trans-4-aminomethylcyclohexanecarboxylic acid) is a medicinal amino acid used in skin whitening care. This study examined the effects of tranexamic acid on the melanocyte activation of the skin induced by an ultraviolet (UV) B eye irradiation. The eye or ear was locally exposed to UVB at a dose of 1.0 kJ/m(2) using a 20SE sunlamp after covering the remaining body surface with aluminum foil. UVB eye irradiation induced melanocyte activation of the skin, similar to that observed following UVB ear irradiation, which was suppressed by the administration of tranexamic acid treatment. The plasma α-melanocyte-stimulating hormone (α-MSH) content was increased by UVB irradiation of the eye; however, the increase in α-MSH was suppressed by tranexamic acid treatment. In addition, UVB eye irradiation induced the up-regulation of prohormone convertase (PC) 2 in the pituitary gland. Meanwhile, the increase in PC2 induced by UVB eye irradiation was suppressed by tranexamic acid treatment. These results clearly indicate that tranexamic acid decreases the expression of PC2, which cleavages from proopiomelanocortin to α-MSH in the pituitary gland, thereby suppressing melanocyte activation. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Repeated intraocular crystallization of ganciclovir in one eye after bilateral intravitreal injections: a case report.

PubMed

Iu, Lawrence P L; Fan, Michelle C Y; Lam, Wai-Ching; Wong, Ian Y H

2018-02-09

Cytomegalovirus (CMV) retinitis is an opportunistic infection that primarily affects immunocompromised individuals. Intravitreal ganciclovir injection monotherapy or in combination with systemic anti-CMV therapy are effective treatments for CMV retinitis. Crystallization of ganciclovir after intravitreal injection is extremely rare. Only two cases had been reported in literature. Crystallization in only one eye after bilateral injections had not been reported before. We hereby report a case of intraocular ganciclovir crystallization in one eye after bilateral intravitreal injections, and repeated crystallization in the same eye after repeated injections. A 79-year-old patient had bilateral cytomegalovirus retinitis and received bilateral intravitreal ganciclovir injections of 2.5 mg in 0.05 ml sterile water. Fundus examination after injection showed formation of needle-shaped, golden-yellow crystals in the vitreous of right eye but not in left eye. The crystals dissolved spontaneously. Repeated bilateral intravitreal ganciclovir injections 4 days later resulted in repeated crystallization of ganciclovir in right eye but not in left eye. The crystals dissolved spontaneously and completely after 5 minutes. Visual acuity remained unchanged and intraocular pressure was normal. Intraocular ganciclovir crystallization could occur after intravitreal injections. It is important to perform fundus examination after injection. The crystals may dissolve rapidly and vitrectomy may not be necessary. Our case suggested intraocular ganciclovir crystallization is an idiosyncratic phenomenon, subjects to distinctive intraocular environment which could be different between two eyes of the same patient. The susceptible intraocular environment could be persistent leading to repeated crystallization.

Us Navy Active Duty Eye Injury Summary Calendar Year 2017

DTIC Science & Technology

This document reports eye injuries within active duty members of the United States Navy for calendar year 2017. Ocular injuries are defined by...specific medical diagnostic codes (International Classification of Diseases). Injuries are categories by type, cause, and occupation. These categories are ...stratified between ambulatory and inpatient. Additionally, data on deployment associated eye injuries are included.

REM sleep and emotional face memory in typically-developing children and children with autism.

PubMed

Tessier, Sophie; Lambert, Andréane; Scherzer, Peter; Jemel, Boutheina; Godbout, Roger

2015-09-01

Relationship between REM sleep and memory was assessed in 13 neurotypical and 13 children with Autistic Spectrum Disorder (ASD). A neutral/positive/negative face recognition task was administered the evening before (learning and immediate recognition) and the morning after (delayed recognition) sleep. The number of rapid eye movements (REMs), beta and theta EEG activity over the visual areas were measured during REM sleep. Compared to neurotypical children, children with ASD showed more theta activity and longer reaction time (RT) for correct responses in delayed recognition of neutral faces. Both groups showed a positive correlation between sleep and performance but different patterns emerged: in neurotypical children, accuracy for recalling neutral faces and overall RT improvement overnight was correlated with EEG activity and REMs; in children with ASD, overnight RT improvement for positive and negative faces correlated with theta and beta activity, respectively. These results suggest that neurotypical and children with ASD use different sleep-related brain networks to process faces. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery.

PubMed

Dang, Yalong; Waxman, Susannah; Wang, Chao; Parikh, Hardik A; Bussel, Igor I; Loewen, Ralitsa T; Xia, Xiaobo; Lathrop, Kira L; Bilonick, Richard A; Loewen, Nils A

2017-05-09

Increasing prevalence and cost of glaucoma have increased the demand for surgeons well trained in newer, microincisional surgery. These procedures occur in a highly confined space, making them difficult to learn by observation or assistance alone as is currently done. We hypothesized that our ex vivo outflow model is sensitive enough to allow computing individual learning curves to quantify progress and refine techniques. Seven trainees performed nine trabectome-mediated ab interno trabeculectomies in pig eyes (n = 63). An expert surgeon rated the procedure using an Operating Room Score (ORS). The extent of outflow beds accessed was measured with canalograms. Data was fitted using mixed effect models. ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 1.4 minutes per eye in a linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. Canalograms revealed that this progress did not correlate well with improvement in outflow, suggesting instead that about 30 eyes are needed for true mastery. This inexpensive pig eye model provides a safe and effective microsurgical training model and allows objective quantification of outcomes for the first time.

Feasibility of utilizing a commercial eye tracker to assess electronic health record use during patient simulation.

PubMed

Gold, Jeffrey Allen; Stephenson, Laurel E; Gorsuch, Adriel; Parthasarathy, Keshav; Mohan, Vishnu

2016-09-01

Numerous reports describe unintended consequences of electronic health record implementation. Having previously described physicians' failures to recognize patient safety issues within our electronic health record simulation environment, we now report on our use of eye and screen-tracking technology to understand factors associated with poor error recognition during an intensive care unit-based electronic health record simulation. We linked performance on the simulation to standard eye and screen-tracking readouts including number of fixations, saccades, mouse clicks and screens visited. In addition, we developed an overall Composite Eye Tracking score which measured when, where and how often each safety item was viewed. For 39 participants, the Composite Eye Tracking score correlated with performance on the simulation (p = 0.004). Overall, the improved performance was associated with a pattern of rapid scanning of data manifested by increased number of screens visited (p = 0.001), mouse clicks (p = 0.03) and saccades (p = 0.004). Eye tracking can be successfully integrated into electronic health record-based simulation and provides a surrogate measure of cognitive decision making and electronic health record usability. © The Author(s) 2015.

Common Sleep Problems (For Teens)

MedlinePlus

... rapid eye movement) sleep make up a sleep cycle . One complete sleep cycle lasts about 90 to 100 minutes. So during ... a person will experience about four or five cycles of sleep. Stages 1 and 2 are periods ...

One-year real-world outcomes in patients receiving fixed-dosing aflibercept for neovascular age-related macular degeneration.

PubMed

Almuhtaseb, H; Kanavati, S; Rufai, S R; Lotery, A J

2017-06-01

PurposeTo investigate 1-year visual and anatomic outcomes of intravitreal aflibercept for neovascular age-related macular degeneration (nAMD) given at a fixed 8-weekly interval.MethodsRetrospective, single-practice data analysis from an electronic medical record system of 255 eyes (223 patients) with treatment-naïve nAMD receiving 8-weekly aflibercept.ResultsMean logarithm of the minimum angle of resolution best-corrected visual acuity (BCVA) improved from 0.66 at baseline to 0.50 at month 11 (P<0.0001). Mean central retinal thickness (CRT) decreased from 311 μm at baseline to 211 μm at month 11 (P<0.0001). Our mean VA gain of eight ETDRS letters was comparable to the VIEW 1 and VIEW 2 Trials' results at the end of year 1. After loading at month 5, mean BCVA was 0.48 (P<0.0001), and mean CRT was 235 μm. At month 5, 143 eyes (56%) were inactive defined by the absence of macular haemorrhage and intraretinal fluid (IRF) and subretinal fluid (SRF) on optical coherence tomography, and 112 eyes (44%) remained active. At month 11, 136 eyes (53%) were inactive, and 119 eyes (47%) remained active. At month 11, 77% of inactive eyes after loading remained inactive, and 77% of the active eyes after loading remained active. At month 11, mean BCVA of the inactive group was 0.51, and mean BCVA of the active group was 0.48 (P=0.54).ConclusionsAflibercept administered by fixed dosing over 1 year improved VA and macular morphology in treatment-naïve eyes. Active lesions at month 11 do not have worse VA outcomes compared with inactive lesions. The macular status after loading is a reliable indicator of disease activity at the end of year 1.

Acute thyroid eye disease (TED): principles of medical and surgical management.

PubMed

Verity, D H; Rose, G E

2013-03-01

The active inflammatory phase of thyroid eye disease (TED) is mediated by the innate immune system, and management is aimed at aborting this self-limited period of autoimmune activity. In most patients with TED, ocular and adnexal changes are mild and management involves controlling thyroid dysfunction, cessation of smoking, and addressing ocular surface inflammation and exposure. In patients with acute moderate disease, this being sufficient to impair orbital functions, immunosuppression reduces the long-term sequelae of acute inflammation, and adjunctive fractionated low-dose orbital radiotherapy is used as a steroid-sparing measure. Elective surgery is often required following moderate TED, be it for proptosis, diplopia, lid retraction, or to debulk the eyelid, and this should be delayed until the disease is quiescent, with the patient stable and weaned off all immunosuppression. Thus, surgical intervention during the active phase of moderate disease is rarely indicated, although clinical experience suggests that, where there is significant orbital congestion, early orbital decompression can limit progression to more severe disease. Acute severe TED poses a major risk of irreversible loss of vision due to marked exposure keratopathy, 'hydraulic' orbital congestion, or compressive optic neuropathy. If performed promptly, retractor recession with or without a suture tarsorrhaphy protects the ocular surface from severe exposure and, in patients not responding to high-dose corticosteroid treatment, decompression of the deep medial orbital wall and floor can rapidly relieve compressive optic neuropathy, as well as alleviate the inflammatory and congestive features of raised orbital pressure.

Acute thyroid eye disease (TED): Principles of medical and surgical management

PubMed Central

Verity, D H; Rose, G E

2013-01-01

The active inflammatory phase of thyroid eye disease (TED) is mediated by the innate immune system, and management is aimed at aborting this self-limited period of autoimmune activity. In most patients with TED, ocular and adnexal changes are mild and management involves controlling thyroid dysfunction, cessation of smoking, and addressing ocular surface inflammation and exposure. In patients with acute moderate disease, this being sufficient to impair orbital functions, immunosuppression reduces the long-term sequelae of acute inflammation, and adjunctive fractionated low-dose orbital radiotherapy is used as a steroid-sparing measure. Elective surgery is often required following moderate TED, be it for proptosis, diplopia, lid retraction, or to debulk the eyelid, and this should be delayed until the disease is quiescent, with the patient stable and weaned off all immunosuppression. Thus, surgical intervention during the active phase of moderate disease is rarely indicated, although clinical experience suggests that, where there is significant orbital congestion, early orbital decompression can limit progression to more severe disease. Acute severe TED poses a major risk of irreversible loss of vision due to marked exposure keratopathy, ‘hydraulic' orbital congestion, or compressive optic neuropathy. If performed promptly, retractor recession with or without a suture tarsorrhaphy protects the ocular surface from severe exposure and, in patients not responding to high-dose corticosteroid treatment, decompression of the deep medial orbital wall and floor can rapidly relieve compressive optic neuropathy, as well as alleviate the inflammatory and congestive features of raised orbital pressure. PMID:23412559

Basal Ganglia Neuronal Activity during Scanning Eye Movements in Parkinson’s Disease

PubMed Central

Sieger, Tomáš; Bonnet, Cecilia; Serranová, Tereza; Wild, Jiří; Novák, Daniel; Růžička, Filip; Urgošík, Dušan; Růžička, Evžen; Gaymard, Bertrand; Jech, Robert

2013-01-01

The oculomotor role of the basal ganglia has been supported by extensive evidence, although their role in scanning eye movements is poorly understood. Nineteen Parkinsońs disease patients, which underwent implantation of deep brain stimulation electrodes, were investigated with simultaneous intraoperative microelectrode recordings and single channel electrooculography in a scanning eye movement task by viewing a series of colored pictures selected from the International Affective Picture System. Four patients additionally underwent a visually guided saccade task. Microelectrode recordings were analyzed selectively from the subthalamic nucleus, substantia nigra pars reticulata and from the globus pallidus by the WaveClus program which allowed for detection and sorting of individual neurons. The relationship between neuronal firing rate and eye movements was studied by crosscorrelation analysis. Out of 183 neurons that were detected, 130 were found in the subthalamic nucleus, 30 in the substantia nigra and 23 in the globus pallidus. Twenty percent of the neurons in each of these structures showed eye movement-related activity. Neurons related to scanning eye movements were mostly unrelated to the visually guided saccades. We conclude that a relatively large number of basal ganglia neurons are involved in eye motion control. Surprisingly, neurons related to scanning eye movements differed from neurons activated during saccades suggesting functional specialization and segregation of both systems for eye movement control. PMID:24223158

The Rate of Visual Field Change in the Ocular Hypertension Treatment Study

PubMed Central

De Moraes, Carlos Gustavo V.; Gardiner, Stuart K.; Liebmann, Jeffrey M.; Cioffi, George A.; Ritch, Robert; Gordon, Mae O.; Kass, Michael A.

2012-01-01

Purpose. To assess the rate of change of visual field (VF) mean deviation (MD) in the Ocular Hypertension Treatment Study (OHTS). Methods. OHTS data were filtered to exclude eyes that had fewer than 10 reliable VFs or less than 5 years of follow-up or that reached a nonglaucomatous endpoint. The rate of change of MD (MDR) was calculated for each eye. Differences were sought between groups of eyes differing in primary open angle glaucoma (POAG) outcome, how POAG was determined, and original randomization. Results. In total, 2609 eyes (1379 participants) met the selection criteria. The mean MDR was −0.08 ± 0.20 dB/y (±SD). POAG eyes (n = 359) had significantly worse MDRs (−0.26 ± 0.36 dB/y) than non-POAG eyes (n = 2250; −0.05 ± 0.14 dB/y; P < 0.001). Eyes that reached POAG endpoints based on only VF change (n = 74; −0.29 ± 0.31 dB/y) or only optic disc change (n = 158; −0.12 ± 0.19 dB/y) had significantly worse MDRs than non-POAG eyes (both P < 0.001). Eyes that reached POAG endpoints for both VF and optic disc change (n = 127) deteriorated more rapidly (−0.42 ± 0.46 dB/y) than eyes showing only VF change (P = 0.017) or only optic disc change (P < 0.001). There was not a significant association between MDR and original OHTS randomization (observe vs. treat, P = 0.168). Conclusions. Eyes that develop POAG have significantly worse MDRs than eyes that do not. Eyes that reached endpoints due to both VF and optic disc change had worse MDRs than eyes displaying change in only one of these. MDR was not significantly associated with randomization, suggesting that MDR may not be the best measure of VF change in early-stage POAG. (ClinicalTrials.gov number, NCT00000125.) PMID:22159015

Rapidly progressive idiopathic lenticular astigmatism.

PubMed

Tint, Naing L; Jayaswal, Rakesh; Masood, Imran; Maharajan, V Senthil

2007-02-01

A myopic 43-year-old woman with early nuclear sclerotic cataract developed more than 11.0 diopters (D) of astigmatism over a 6-month period. This was found to be lenticular in origin. Phacoemulsification with intraocular lens implantation was performed, resulting in residual astigmatism of 0.75 D. To our knowledge, this is the first case of rapidly progressive lenticular astigmatism in an otherwise healthy eye with early nuclear sclerotic cataract.

Measuring eye movements during locomotion: filtering techniques for obtaining velocity signals from a video-based eye monitor

NASA Technical Reports Server (NTRS)

Das, V. E.; Thomas, C. W.; Zivotofsky, A. Z.; Leigh, R. J.

1996-01-01

Video-based eye-tracking systems are especially suited to studying eye movements during naturally occurring activities such as locomotion, but eye velocity records suffer from broad band noise that is not amenable to conventional filtering methods. We evaluated the effectiveness of combined median and moving-average filters by comparing prefiltered and postfiltered records made synchronously with a video eye-tracker and the magnetic search coil technique, which is relatively noise free. Root-mean-square noise was reduced by half, without distorting the eye velocity signal. To illustrate the practical use of this technique, we studied normal subjects and patients with deficient labyrinthine function and compared their ability to hold gaze on a visual target that moved with their heads (cancellation of the vestibulo-ocular reflex). Patients and normal subjects performed similarly during active head rotation but, during locomotion, patients held their eyes more steadily on the visual target than did subjects.

Visibility graph analysis of very short-term heart rate variability during sleep

NASA Astrophysics Data System (ADS)

Hou, F. Z.; Li, F. W.; Wang, J.; Yan, F. R.

2016-09-01

Based on a visibility-graph algorithm, complex networks were constructed from very short-term heart rate variability (HRV) during different sleep stages. Network measurements progressively changed from rapid eye movement (REM) sleep to light sleep and then deep sleep, exhibiting promising ability for sleep assessment. Abnormal activation of the cardiovascular controls with enhanced 'small-world' couplings and altered fractal organization during REM sleep indicates that REM could be a potential risk factor for adverse cardiovascular event, especially in males, older individuals, and people who are overweight. Additionally, an apparent influence of gender, aging, and obesity on sleep was demonstrated in healthy adults, which may be helpful for establishing expected sleep-HRV patterns in different populations.

Update of sleep alterations in depression

PubMed Central

Medina, Andrés Barrera; Lechuga, DeboraYoaly Arana; Escandón, Oscar Sánchez; Moctezuma, Javier Velázquez

2014-01-01

Sleep disturbances in depression are up to 70%. Patients frequently have difficulty in falling asleep, frequent awakenings during the night and non-restorative sleep. Sleep abnormalities in depression are mainly characterized by increased rapid eye movement (REM) sleep and reduced slow wave sleep. Among the mechanisms of sleep disturbances in depression are hyperactivation of the hypothalamic-pituitary-adrenal axis, CLOCK gene polymorphism and primary sleep disorders. The habenula is a structure regulating the activities of monoaminergic neurons in the brain. The hyperactivation of the habenula has also been implicated, together with sleep disturbances, in depression. The presence of depression in primary sleep disorders is common. Sleep disturbances treatment include pharmacotherapy or Cognitive Behavioral Therapy. PMID:26483922

Debate over NAFTA's effect on health care a sign medicare will be dominant election issue

PubMed Central

Gray, Charlotte

1996-01-01

Does the North American Free Trade Agreement (NAFTA) pose a threat to Canada's medicare system? There was a flurry of political activity in March over concerns that US health care companies were eagerly eyeing the Canadian market because NAFTA had opened it to them. The issue disappeared almost as quickly as it arrived, but it caught the attention of federal politicians, who hastened to negotiate to protect all existing health and social services. The rapidity with which the question grabbed the headlines was another reminder that health care remains one of the key political issues in Canada, and politicians will ignore it at their peril.

Spatial transformations between superior colliculus visual and motor response fields during head-unrestrained gaze shifts.

PubMed

Sadeh, Morteza; Sajad, Amirsaman; Wang, Hongying; Yan, Xiaogang; Crawford, John Douglas

2015-12-01

We previously reported that visuomotor activity in the superior colliculus (SC)--a key midbrain structure for the generation of rapid eye movements--preferentially encodes target position relative to the eye (Te) during low-latency head-unrestrained gaze shifts (DeSouza et al., 2011). Here, we trained two monkeys to perform head-unrestrained gaze shifts after a variable post-stimulus delay (400-700 ms), to test whether temporally separated SC visual and motor responses show different spatial codes. Target positions, final gaze positions and various frames of reference (eye, head, and space) were dissociated through natural (untrained) trial-to-trial variations in behaviour. 3D eye and head orientations were recorded, and 2D response field data were fitted against multiple models by use of a statistical method reported previously (Keith et al., 2009). Of 60 neurons, 17 showed a visual response, 12 showed a motor response, and 31 showed both visual and motor responses. The combined visual response field population (n = 48) showed a significant preference for Te, which was also preferred in each visual subpopulation. In contrast, the motor response field population (n = 43) showed a preference for final (relative to initial) gaze position models, and the Te model was statistically eliminated in the motor-only population. There was also a significant shift of coding from the visual to motor response within visuomotor neurons. These data confirm that SC response fields are gaze-centred, and show a target-to-gaze transformation between visual and motor responses. Thus, visuomotor transformations can occur between, and even within, neurons within a single frame of reference and brain structure. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Efficacy and safety of two new formulations of artificial tears in subjects with dry eye disease: a 3-month, multicenter, active-controlled, randomized trial

PubMed Central

Simmons, Peter A; Liu, Haixia; Carlisle-Wilcox, Cindy; Vehige, Joseph G

2015-01-01

Purpose To evaluate and compare the efficacy and safety of two investigational artificial tear formulations (CHO-1 and CHO-2) containing carmellose sodium, hyaluronic acid at different concentrations, and osmoprotectants, with a standard carmellose sodium-containing formulation (Refresh Tears [RT]) in the treatment of dry eye disease. Subjects and methods In this 3-month, double-masked, multicenter study, subjects (n=305) were randomized 1:1:1 to receive CHO-1, CHO-2, or RT, used as needed but at least twice daily. The primary endpoint was change in ocular surface disease index (OSDI) score from baseline to day 90. Other key outcomes included symptoms evaluated on a visual analog scale, corneal and conjunctival staining, and adverse events. Results OSDI scores and dry eye symptoms showed a rapid and sustained reduction from baseline in each group. Both CHO-1 and CHO-2 met the primary efficacy endpoint of noninferiority to RT in day 90 OSDI score change from baseline. OSDI ocular symptoms subscale improved more with CHO-1 than CHO-2 (P=0.048). In subjects with clinically relevant baseline ocular surface staining (>14 total score of a maximum of 55), day 90 improvements were greater with CHO-1 and CHO-2 than RT (P≤0.044). Day 90 improvements in OSDI ocular symptoms subscale scores were also greater with CHO-1 than RT (P<0.007) in subjects with clinically relevant ocular staining. All treatments were well tolerated. Conclusion Both combination artificial tear formulations were efficacious and well tolerated in subjects with dry eye. CHO-1 demonstrated the best performance in improving ocular symptoms and reducing ocular staining in this heterogeneous study population. PMID:25931807

An EEG-Based Person Authentication System with Open-Set Capability Combining Eye Blinking Signals

PubMed Central

Wu, Qunjian; Zeng, Ying; Zhang, Chi; Tong, Li; Yan, Bin

2018-01-01

The electroencephalogram (EEG) signal represents a subject’s specific brain activity patterns and is considered as an ideal biometric given its superior forgery prevention. However, the accuracy and stability of the current EEG-based person authentication systems are still unsatisfactory in practical application. In this paper, a multi-task EEG-based person authentication system combining eye blinking is proposed, which can achieve high precision and robustness. Firstly, we design a novel EEG-based biometric evoked paradigm using self- or non-self-face rapid serial visual presentation (RSVP). The designed paradigm could obtain a distinct and stable biometric trait from EEG with a lower time cost. Secondly, the event-related potential (ERP) features and morphological features are extracted from EEG signals and eye blinking signals, respectively. Thirdly, convolutional neural network and back propagation neural network are severally designed to gain the score estimation of EEG features and eye blinking features. Finally, a score fusion technology based on least square method is proposed to get the final estimation score. The performance of multi-task authentication system is improved significantly compared to the system using EEG only, with an increasing average accuracy from 92.4% to 97.6%. Moreover, open-set authentication tests for additional imposters and permanence tests for users are conducted to simulate the practical scenarios, which have never been employed in previous EEG-based person authentication systems. A mean false accepted rate (FAR) of 3.90% and a mean false rejected rate (FRR) of 3.87% are accomplished in open-set authentication tests and permanence tests, respectively, which illustrate the open-set authentication and permanence capability of our systems. PMID:29364848

An EEG-Based Person Authentication System with Open-Set Capability Combining Eye Blinking Signals.

PubMed

Wu, Qunjian; Zeng, Ying; Zhang, Chi; Tong, Li; Yan, Bin

2018-01-24

The electroencephalogram (EEG) signal represents a subject's specific brain activity patterns and is considered as an ideal biometric given its superior forgery prevention. However, the accuracy and stability of the current EEG-based person authentication systems are still unsatisfactory in practical application. In this paper, a multi-task EEG-based person authentication system combining eye blinking is proposed, which can achieve high precision and robustness. Firstly, we design a novel EEG-based biometric evoked paradigm using self- or non-self-face rapid serial visual presentation (RSVP). The designed paradigm could obtain a distinct and stable biometric trait from EEG with a lower time cost. Secondly, the event-related potential (ERP) features and morphological features are extracted from EEG signals and eye blinking signals, respectively. Thirdly, convolutional neural network and back propagation neural network are severally designed to gain the score estimation of EEG features and eye blinking features. Finally, a score fusion technology based on least square method is proposed to get the final estimation score. The performance of multi-task authentication system is improved significantly compared to the system using EEG only, with an increasing average accuracy from 92.4% to 97.6%. Moreover, open-set authentication tests for additional imposters and permanence tests for users are conducted to simulate the practical scenarios, which have never been employed in previous EEG-based person authentication systems. A mean false accepted rate (FAR) of 3.90% and a mean false rejected rate (FRR) of 3.87% are accomplished in open-set authentication tests and permanence tests, respectively, which illustrate the open-set authentication and permanence capability of our systems.

Effects of combat training on visuomotor performance in children aged 9 to 12 years - an eye-tracking study.

PubMed

Ju, Yan-Ying; Liu, Yen-Hsiu; Cheng, Chih-Hsiu; Lee, Yu-Lung; Chang, Shih-Tsung; Sun, Chi-Chin; Cheng, Hsin-Yi Kathy

2018-02-07

Data on visuomotor performance in combat training and the effects of combat training on visuomotor performance are limited. This study aimed to investigate the effects of a specially designed combat sports (CS) training program on the visuomotor performance levels of children. A pre-post comparative design was implemented. A total of 26 students aged 9-12 years underwent 40-min CS training sessions twice a week for 8 weeks during their physical education classes. The CS training program was designed by a karate coach and a motor control specialist. The other 30 students continued their regular activities and were considered as a control group. Each student's eye movement was monitored using an eye tracker, whereas the motor performance was measured using a target hitting system with a program-controlled microprocessor. The measurements were taken 8 weeks before (baseline), 1 day before (pretest), and 1 week after (posttest) the designated training program. The task used for evaluating these students was hitting or tracking random illuminated targets as rapidly as possible. A two-way analysis of variance [group(2) × time(3)] with repeated measures of time was performed for statistical analysis. For the children who received combat training, although the eye response improvement was not significant, both the primary and secondary saccade onset latencies were significantly earlier compared to the children without combat training. Both groups of students exhibited improvement in their hit response times during the target hitting tasks. The current finding supported the notion that sports training efforts essentially enhance visuomotor function in children aged 9-12 years, and combat training facilitates an earlier secondary saccade onset.

Human agency beliefs influence behaviour during virtual social interactions.

PubMed

Caruana, Nathan; Spirou, Dean; Brock, Jon

2017-01-01

In recent years, with the emergence of relatively inexpensive and accessible virtual reality technologies, it is now possible to deliver compelling and realistic simulations of human-to-human interaction. Neuroimaging studies have shown that, when participants believe they are interacting via a virtual interface with another human agent, they show different patterns of brain activity compared to when they know that their virtual partner is computer-controlled. The suggestion is that users adopt an "intentional stance" by attributing mental states to their virtual partner. However, it remains unclear how beliefs in the agency of a virtual partner influence participants' behaviour and subjective experience of the interaction. We investigated this issue in the context of a cooperative "joint attention" game in which participants interacted via an eye tracker with a virtual onscreen partner, directing each other's eye gaze to different screen locations. Half of the participants were correctly informed that their partner was controlled by a computer algorithm ("Computer" condition). The other half were misled into believing that the virtual character was controlled by a second participant in another room ("Human" condition). Those in the "Human" condition were slower to make eye contact with their partner and more likely to try and guide their partner before they had established mutual eye contact than participants in the "Computer" condition. They also responded more rapidly when their partner was guiding them, although the same effect was also found for a control condition in which they responded to an arrow cue. Results confirm the influence of human agency beliefs on behaviour in this virtual social interaction context. They further suggest that researchers and developers attempting to simulate social interactions should consider the impact of agency beliefs on user experience in other social contexts, and their effect on the achievement of the application's goals.

Ethical Issues in Transnational Eye Banking.

PubMed

Martin, Dominique E; Kelly, Richard; Jones, Gary L A; Machin, Heather; Pollock, Graeme A

2017-02-01

To review ethical issues that may arise in the setting of transnational eye banking activities, such as when exporting or importing corneal tissue for transplantation. A principle-based normative analysis of potential common dilemmas in transnational eye banking activities was performed. Transnational activities in eye banking, like those in other fields involving procurement and use of medical products of human origin, may present a number of ethical issues for policy makers and professionals. Key ethical concerns include the potential impact of export or import activities on self-sufficiency of corneal tissue supply within exporting and importing countries; potential disclosure requirements when obtaining consent or authorization for ocular tissue donation when donations may be exported; and difficulties inherent in assuring equity in the allocation of tissues available for export and in establishing and respecting standards of safety and quality across different jurisdictions. Further analysis of specific ethical issues in eye banking is necessary to inform development of guidelines and other governance tools that will assist policy makers and professionals to support ethical practice.

System identification of perilymphatic fistula in an animal model

NASA Technical Reports Server (NTRS)

Wall, C. 3rd; Casselbrant, M. L.

1992-01-01

An acute animal model has been developed in the chinchilla for the study of perilymphatic fistulas. Micropunctures were made in three sites to simulate bony, round window, and oval window fistulas. The eye movements in response to pressure applied to the external auditory canal were recorded after micropuncture induction and in preoperative controls. The main pressure stimulus was a pseudorandom binary sequence (PRBS) that rapidly changed between plus and minus 200 mm of water. The PRBS stimulus, with its wide frequency bandwidth, produced responses clearly above the preoperative baseline in 78 percent of the runs. The response was better between 0.5 and 3.3 Hz than it was below 0.5 Hz. The direction of horizontal eye movement was toward the side of the fistula with positive pressure applied in 92 percent of the runs. Vertical eye movements were also observed. The ratio of vertical eye displacement to horizontal eye displacement depended upon the site of the micropuncture induction. Thus, such a ratio measurement may be clinically useful in the noninvasive localization of perilymphatic fistulas in humans.

One night of sleep is insufficient to achieve sleep-to-forget emotional decontextualisation processes.

PubMed

Deliens, Gaétane; Peigneux, Philippe

2014-01-01

Neutral memories unbind from their emotional acquisition context when sleep is allowed the night after learning and testing takes place after two additional nights of sleep. However, mood-dependent memory (MDM) effects are not abolished after a restricted sleep episode mostly featuring non rapid-eye-movement (NREM) or rapid-eye-movement (REM) sleep. Here, we tested whether (1) one night of sleep featuring several NREM-REM sleep cycles is sufficient to suppress MDM effects and (2) a neutral mood is a sufficiently contrasting state to induce MDM effects, i.e. interfere with the recall of information learned in happy or sad states. Results disclosed MDM effects both in the post-learning sleep and wake conditions, with better recall in congruent than incongruent emotional contexts. Our findings suggest that the emotional unbinding needs several consecutive nights of sleep to be complete, and that even subtle mood changes are sufficient to produce MDM effects.

Sleep Disturbances Associated with Parkinson's Disease

PubMed Central

Suzuki, Keisuke; Miyamoto, Masayuki; Miyamoto, Tomoyuki; Iwanami, Masaoki; Hirata, Koichi

2011-01-01

Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD) patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD. PMID:21876839

A rapid, naked-eye detection of hypochlorite and bisulfite using a robust and highly-photostable indicator dye Quinaldine Red in aqueous medium

NASA Astrophysics Data System (ADS)

Dutta, Tanoy; Chandra, Falguni; Koner, Apurba L.

2018-02-01

A ;naked-eye; detection of health hazardous bisulfite (HSO3-) and hypochlorite (ClO-) using an indicator dye (Quinaldine Red, QR) in a wide range of pH is demonstrated. The molecule contains a quinoline moiety linked to an N,N-dimethylaniline moiety with a conjugated double bond. Treatment of QR with HSO3- and ClO-, in aqueous solution at near-neutral pH, resulted in a colorless product with high selectivity and sensitivity. The detection limit was 47.8 μM and 0.2 μM for HSO3- and ClO- respectively. However, ClO- was 50 times more sensitive and with 2 times faster response compared to HSO3-. The detail characterization and related analysis demonstrate the potential of QR for a rapid, robust and highly efficient colorimetric sensor for the practical applications to detect hypochlorite in water samples.

Rapid detection of HSO4- in water: Novel immobilized azo-azomethine colorimetric anion receptors on solid supports

NASA Astrophysics Data System (ADS)

Hezaveh, Saba Mahdavi; Khanmohammadi, Hamid; Zendehdel, Mojgan

2018-06-01

The immobilized azo-azomethine receptors on amorphous SiO2, S-B, SiO2 nanoparticles, S-NPs, and NaY zeolite, S-ZY, have been prepared and applied as solid phase sensors for detection of HSO4-, over other interfering anions, in 100% aqueous media. Remarkably, S-B and S-ZY show unique and rapid sensitivity towards HSO4-, which could it easily visualized through naked eye detection even at 5 × 10-4 mol L-1 and 4 × 10-4 mol L-1, respectively. The fabricated solid phase sensors were characterized using powder XRD diffraction, TGA-DTA, FE-SEM and also FT-IR techniques. Moreover, the related molecular anion receptor, HL, has been prepared and used for naked eye detection of F- and AcO-, in dry DMSO. The anions recognition ability of HL was also evaluated using UV-Vis and 1H NMR spectroscopic methods.

Automated analysis of connected speech reveals early biomarkers of Parkinson's disease in patients with rapid eye movement sleep behaviour disorder.

PubMed

Hlavnička, Jan; Čmejla, Roman; Tykalová, Tereza; Šonka, Karel; Růžička, Evžen; Rusz, Jan

2017-02-02

For generations, the evaluation of speech abnormalities in neurodegenerative disorders such as Parkinson's disease (PD) has been limited to perceptual tests or user-controlled laboratory analysis based upon rather small samples of human vocalizations. Our study introduces a fully automated method that yields significant features related to respiratory deficits, dysphonia, imprecise articulation and dysrhythmia from acoustic microphone data of natural connected speech for predicting early and distinctive patterns of neurodegeneration. We compared speech recordings of 50 subjects with rapid eye movement sleep behaviour disorder (RBD), 30 newly diagnosed, untreated PD patients and 50 healthy controls, and showed that subliminal parkinsonian speech deficits can be reliably captured even in RBD patients, which are at high risk of developing PD or other synucleinopathies. Thus, automated vocal analysis should soon be able to contribute to screening and diagnostic procedures for prodromal parkinsonian neurodegeneration in natural environments.

Dynamics of sleep/wake determination--Normal and abnormal

NASA Astrophysics Data System (ADS)

Mahowald, Mark W.; Schenck, Carlos H.; O'Connor, Kevin A.

1991-10-01

Virtually all members of the animal kingdom experience a relentless and powerful cycling of states of being: wakefulness, rapid eye movement sleep, and nonrapid eye movement sleep. Each of these states is composed of a number of physiologic variables generated in a variety of neural structures. The predictable oscillations of these states are driven by presumed neural pacemakers which are entrained to the 24 h geophysical environment by the light/dark cycle. Experiments in nature have indicated that wake/sleep rhythm perturbations may occur either involving desynchronization of the basic 24 h wake/sleep cycle within the geophysical 24 h cycle (circadian rhythm disturbances) or involving the rapid oscillation or incomplete declaration of state (such as narcolepsy). The use of phase spaces to describe states of being may be of interest in the description of state determination in both illness and health. Some fascinating clinical and experimental phenomena may represent bifurcations in the sleep/wake control system.

The role of pili in Bacillus cereus intraocular infection.

PubMed

Callegan, Michelle C; Parkunan, Salai Madhumathi; Randall, C Blake; Coburn, Phillip S; Miller, Frederick C; LaGrow, Austin L; Astley, Roger A; Land, Craig; Oh, So-Young; Schneewind, Olaf

2017-06-01

Bacterial endophthalmitis is a potentially blinding intraocular infection. The bacterium Bacillus cereus causes a devastating form of this disease which progresses rapidly, resulting in significant inflammation and loss of vision within a few days. The outer surface of B. cereus incites the intraocular inflammatory response, likely through interactions with innate immune receptors such as TLRs. This study analyzed the role of B. cereus pili, adhesion appendages located on the bacterial surface, in experimental endophthalmitis. To test the hypothesis that the presence of pili contributed to intraocular inflammation and virulence, we analyzed the progress of experimental endophthalmitis in mouse eyes infected with wild type B. cereus (ATCC 14579) or its isogenic pilus-deficient mutant (ΔbcpA-srtD-bcpB or ΔPil). One hundred CFU were injected into the mid-vitreous of one eye of each mouse. Infections were analyzed by quantifying intraocular bacilli and retinal function loss, and by histology from 0 to 12 h postinfection. In vitro growth and hemolytic phenotypes of the infecting strains were also compared. There was no difference in hemolytic activity (1:8 titer), motility, or in vitro growth (p > 0.05, every 2 h, 0-18 h) between wild type B. cereus and the ΔPil mutant. However, infected eyes contained greater numbers of wild type B. cereus than ΔPil during the infection course (p ≤ 0.05, 3-12 h). Eyes infected with wild type B. cereus experienced greater losses in retinal function than eyes infected with the ΔPil mutant, but the differences were not always significant. Eyes infected with ΔPil or wild type B. cereus achieved similar degrees of severe inflammation. The results indicated that the intraocular growth of pilus-deficient B. cereus may have been better controlled, leading to a trend of greater retinal function in eyes infected with the pilus-deficient strain. Although this difference was not enough to significantly alter the severity of the inflammatory response, these results suggest a potential role for pili in protecting B. cereus from clearance during the early stages of endophthalmitis, which is a newly described virulence mechanism for this organism and this infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

Smooth pursuitlike eye movements evoked by microstimulation in macaque nucleus reticularis tegmenti pontis.

PubMed

Yamada, T; Suzuki, D A; Yee, R D

1996-11-01

1. Smooth pursuitlike eye movements were evoked with low current microstimulation delivered to rostral portions of the nucleus reticularis tegmenti pontis (rNRTP) in alert macaques. Microstimulation sites were selected by the observation of modulations in single-cell firing rates that were correlated with periodic smoothpursuit eye movements. Current intensities ranged from 10 to 120 microA and were routinely < 40 microA. Microstimulation was delivered either in the dark with no fixation, 100 ms after a fixation target was extinguished, or during maintained fixation of a stationary or moving target. Evoked eye movements also were studied under open-loop conditions with the target image stabilized on the retina. 2. Eye movements evoked in the absence of a target rapidly accelerated to a constant velocity that was maintained for the duration of the microstimulation. Evoked eye speeds ranged from 3.7 to 23 deg/s and averaged 11 deg/s. Evoked eye speed appeared to be linearly related to initial eye position with a sensitivity to initial eye position that averaged 0.23 deg.s-1.deg-1. While some horizontal and oblique smooth eye movements were elicited, microstimulation resulted in upward eye movements in 89% of the sites. 3. Evoked eye speed was found to be dependent on microstimulation pulse frequency and current intensity. Within limits, evoked eye speed increased with increases in stimulation frequency or current intensity. For stimulation frequencies < 300-400 Hz, only smooth pursuit-like eye movements were evoked. At higher stimulation frequencies, accompanying saccades consistently were elicited. 4. Feedback of retinal image motion interacted with the evoked eye movements to decrease eye speed if the visual motion was in the opposite direction as the evoked, pursuit-like eye movements. 5. The results implicate rNRTP as part of the neuronal substrate that controls smooth-pursuit eye movements. NRTP appears to be divided functionally into a rostral, pursuit-related portion and a caudal, saccade-related area. rNRTP is a component of a corticopontocerebellar circuit that presumably involves the pursuit area of the frontal eye field and that parallels the middle and medial superior temporal cerebral cortical/dorsalateral pontine nucleus (MT/MST-DLPN-cerebellum) pathway known to be involved also with regulating smooth-pursuit eye movements.

Characterization of Retinal Disease Progression in a 1-Year Longitudinal Study of Eyes With Mild Nonproliferative Retinopathy in Diabetes Type 2.

PubMed

Ribeiro, Luisa; Bandello, Francesco; Tejerina, Amparo Navea; Vujosevic, Stela; Varano, Monica; Egan, Catherine; Sivaprasad, Sobha; Menon, Geeta; Massin, Pascale; Verbraak, Frank D; Lund-Andersen, Henrik; Martinez, Jose P; Jürgens, Ignasi; Smets, Erica; Coriat, Caroline; Wiedemann, Peter; Ágoas, Victor; Querques, Giuseppe; Holz, Frank G; Nunes, Sandrina; Neves, Catarina; Cunha-Vaz, José

2015-08-01

To identify eyes of patients with diabetes type 2 that show progression of retinal disease within a 1-year period using noninvasive techniques. Three hundred seventy-four type 2 diabetic patients with mild nonproliferative diabetic retinopathy (Early Treatment Diabetic Retinopathy Study [ETDRS] level 20 or 35) were included in a 12-month prospective observational study to identify retinopathy progression. Four visits were scheduled at 0, 3, 6, and 12 months. Microaneurysm (MA) activity using the RetmarkerDR and retinal thickness using spectral-domain optical coherence tomography (SD-OCT) were assessed by a central reading center at all visits and ETDRS severity level in the first and last visits. Three hundred thirty-one eyes/patients completed the study. Microaneurysm formation rate greater than or equal to 2 was present in 68.1% of the eyes and MA turnover greater than or equal to 6 in 54.0% at month 6. Higher MA turnover values were registered in eyes that showed progression in ETDRS severity level (P < 0.03). There were also significant correlations between increased microaneurysm activity and increases in retinal thickness. Spectral-domain OCT identified clinical macular edema in 24 eyes/patients (6.7%) and subclinical macular edema in 104 eyes/patients (28.9%) at baseline. Progression of retinal thickening was registered in eyes that had either subclinical or clinical macular edema at baseline. Changes in MA activity measured with RetmarkerDR and in central retinal thickness in eyes with mild nonproliferative diabetic retinopathy and diabetes type 2 are able to identify eyes at risk of progression. These eyes/patients should be selected for inclusion in future clinical trials of drugs targeted to prevent diabetic retinopathy progression to vision-threatening complications. (ClinicalTrials.gov number, NCT01145599.)

Treatment with galectin-1 eye drops regulates mast cell degranulation and attenuates the severity of conjunctivitis.

PubMed

Mello-Bosnic, Claudia; Gimenes, Alexandre Dantas; Oliani, Sonia Maria; Gil, Cristiane Damas

2018-05-31

Galectin-1 (Gal-1) is a β-galactoside-binding protein with diverse biological activities in the pathogenesis of inflammation, however the mechanisms by which Gal-1 modulates cellular responses in allergic inflammatory processes have not been fully determined. In this study, we evaluated the therapeutic potential of Gal-1 eye drops in an experimental model of conjunctivitis. Wistar rats received a topical application of compound (C)48/80 (100 mg/ml) into right eyes and a drop of vehicle into the contralateral eye. Another group of rats received Gal-1 (0.3 or 3 μg/eye) or sodium cromoglycate (SCG; 40 mg/ml) in both eyes and, after 15 min, right eye was challenged with C48/80. Conjunctivitis-induced by C48/80 was characterized by severe eyelid oedema and tearing, but clinical signs were ameliorated by eye drop doses of both Gal-1 (0.3/3 μg) and SCG. As expected, an increased proportion of degranulated mast cells (62%, P < 0.01) and lower histamine levels were observed after 6 h of C48/80 challenge, compared to control (32%). This effect was abrogated by Gal-1 and SCG, which reduced mast cell degranulation (31-36%), eosinophil migration and eosinophil peroxidase levels in the eyes. Gal-1 (3 μg) and SCG treatments also decreased IL-4 levels, as well as activation of mitogen activated protein kinases compared to untreated C48/80 eyes. Our findings suggest that Gal-1 eye drops represent a new therapeutic strategy for ocular allergic inflammation. Copyright © 2018 Elsevier B.V. All rights reserved.

Contribution of the frontal eye field to gaze shifts in the head-unrestrained rhesus monkey: neuronal activity.

PubMed

Knight, T A

2012-12-06

The frontal eye field (FEF) has a strong influence on saccadic eye movements with the head restrained. With the head unrestrained, eye saccades combine with head movements to produce large gaze shifts, and microstimulation of the FEF evokes both eye and head movements. To test whether the dorsomedial FEF provides commands for the entire gaze shift or its separate eye and head components, we recorded extracellular single-unit activity in monkeys trained to make large head-unrestrained gaze shifts. We recorded 80 units active during gaze shifts, and closely examined 26 of these that discharged a burst of action potentials that preceded horizontal gaze movements. These units were movement or visuomovement related and most exhibited open movement fields with respect to amplitude. To reveal the relations of burst parameters to gaze, eye, and/or head movement metrics, we used behavioral dissociations of gaze, eye, and head movements and linear regression analyses. The burst number of spikes (NOS) was strongly correlated with movement amplitude and burst temporal parameters were strongly correlated with movement temporal metrics for eight gaze-related burst neurons and five saccade-related burst neurons. For the remaining 13 neurons, the NOS was strongly correlated with the head movement amplitude, but burst temporal parameters were most strongly correlated with eye movement temporal metrics (head-eye-related burst neurons, HEBNs). These results suggest that FEF units do not encode a command for the unified gaze shift only; instead, different units may carry signals related to the overall gaze shift or its eye and/or head components. Moreover, the HEBNs exhibit bursts whose magnitude and timing may encode a head displacement signal and a signal that influences the timing of the eye saccade, thereby serving as a mechanism for coordinating the eye and head movements of a gaze shift. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

Combined central retinal artery and vein occlusion with optic perineuritis following herpes zoster dermatitis in an immunocompetent child.

PubMed

Bansal, Reema; Singh, Ramandeep; Takkar, Aastha; Lal, Vivek

2017-11-01

A 15-year-old healthy boy developed acute, rapidly progressing visual loss in left eye following herpes zoster dermatitis, with a combined central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO), along with optic perineuritis. Laboratory tests were negative. Despite an empirical, intensive antiviral treatment with systemic corticosteroids, and vision could not be restored in the affected eye. Herpes zoster dermatitis, in an immunocompetent individual, may be associated with a combined CRAO and CRVO along with optic perineuritis, leading to profound visual loss.

Back to basics: naked-eye astronomical observation

NASA Astrophysics Data System (ADS)

Barclay, Charles

2003-09-01

For pupils of both sexes and all ages from about six upwards, the subject of Astronomy holds many fascinations - the rapid changes in knowledge, the large resource of available IT packages and above all the beautiful pictures from Hubble and the large Earth-based telescopes. This article, however, stresses the excitement and importance of naked-eye (unaided) first-hand observation, where light pollution allows, and suggests some techniques that may be used to enthuse and introduce youngsters to the glory of the night sky without recourse to computer screens.

CHANGE: Anthropogenic change through the eyes of a child

NASA Astrophysics Data System (ADS)

Kerlow, Isaac

2017-04-01

Constant change is a natural part of Earth's life, and its interconnected systems can easily adapt to slow change. But life is at risk when the natural balance gets disrupted by rapid change. This presentation focuses on the interdisciplinary development and production of CHANGE, a short animated film that shows how human growth and prosperity have changed Planet Earth. The film presents the essence of anthropogenic climate change as seen through the eyes of a pre-teen child. Watch the official trailer here: https://vimeo.com/187618128

Network-dependent modulation of brain activity during sleep.

PubMed

Watanabe, Takamitsu; Kan, Shigeyuki; Koike, Takahiko; Misaki, Masaya; Konishi, Seiki; Miyauchi, Satoru; Miyahsita, Yasushi; Masuda, Naoki

2014-09-01

Brain activity dynamically changes even during sleep. A line of neuroimaging studies has reported changes in functional connectivity and regional activity across different sleep stages such as slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep. However, it remains unclear whether and how the large-scale network activity of human brains changes within a given sleep stage. Here, we investigated modulation of network activity within sleep stages by applying the pairwise maximum entropy model to brain activity obtained by functional magnetic resonance imaging from sleeping healthy subjects. We found that the brain activity of individual brain regions and functional interactions between pairs of regions significantly increased in the default-mode network during SWS and decreased during REM sleep. In contrast, the network activity of the fronto-parietal and sensory-motor networks showed the opposite pattern. Furthermore, in the three networks, the amount of the activity changes throughout REM sleep was negatively correlated with that throughout SWS. The present findings suggest that the brain activity is dynamically modulated even in a sleep stage and that the pattern of modulation depends on the type of the large-scale brain networks. Copyright © 2014 Elsevier Inc. All rights reserved.

fMRI evidence for sensorimotor transformations in human cortex during smooth pursuit eye movements.

PubMed

Kimmig, H; Ohlendorf, S; Speck, O; Sprenger, A; Rutschmann, R M; Haller, S; Greenlee, M W

2008-01-01

Smooth pursuit eye movements (SP) are driven by moving objects. The pursuit system processes the visual input signals and transforms this information into an oculomotor output signal. Despite the object's movement on the retina and the eyes' movement in the head, we are able to locate the object in space implying coordinate transformations from retinal to head and space coordinates. To test for the visual and oculomotor components of SP and the possible transformation sites, we investigated three experimental conditions: (I) fixation of a stationary target with a second target moving across the retina (visual), (II) pursuit of the moving target with the second target moving in phase (oculomotor), (III) pursuit of the moving target with the second target remaining stationary (visuo-oculomotor). Precise eye movement data were simultaneously measured with the fMRI data. Visual components of activation during SP were located in the motion-sensitive, temporo-parieto-occipital region MT+ and the right posterior parietal cortex (PPC). Motor components comprised more widespread activation in these regions and additional activations in the frontal and supplementary eye fields (FEF, SEF), the cingulate gyrus and precuneus. The combined visuo-oculomotor stimulus revealed additional activation in the putamen. Possible transformation sites were found in MT+ and PPC. The MT+ activation evoked by the motion of a single visual dot was very localized, while the activation of the same single dot motion driving the eye was rather extended across MT+. The eye movement information appeared to be dispersed across the visual map of MT+. This could be interpreted as a transfer of the one-dimensional eye movement information into the two-dimensional visual map. Potentially, the dispersed information could be used to remap MT+ to space coordinates rather than retinal coordinates and to provide the basis for a motor output control. A similar interpretation holds for our results in the PPC region.

Rapid target foraging with reach or gaze: The hand looks further ahead than the eye

PubMed Central

2017-01-01

Real-world tasks typically consist of a series of target-directed actions and often require choices about which targets to act on and in what order. Such choice behavior can be assessed from an optimal foraging perspective whereby target selection is shaped by a balance between rewards and costs. Here we evaluated such decision-making in a rapid movement foraging task. On a given trial, participants were presented with 15 targets of varying size and value and were instructed to harvest as much reward as possible by either moving a handle to the targets (hand task) or by briefly fixating them (eye task). The short trial duration enabled participants to harvest about half the targets, ensuring that total reward was due to choice behavior. We developed a probabilistic model to predict target-by-target harvesting choices that considered the rewards and movement-related costs (i.e., target distance and size) associated with the current target as well as future targets. In the hand task, in comparison to the eye task, target choice was more strongly influenced by movement-related costs and took into account a greater number of future targets, consistent with the greater costs associated with arm movement. In both tasks, participants exhibited near-optimal behaviour and in a constrained version of the hand task in which choices could only be based on target positions, participants consistently chose among the shortest movement paths. Our results demonstrate that people can rapidly and effectively integrate values and movement-related costs associated with current and future targets when sequentially harvesting targets. PMID:28683138

Sleep Architecture Relates to Daytime Affect and Somatic Complaints in Clinically Anxious but Not Healthy Children.

PubMed

Palmer, Cara A; Alfano, Candice A

2017-01-01

It is increasingly clear that seminal sleep-affective relationships begin to take root in childhood, yet studies exploring how nighttime sleep characteristics relate to daytime affective symptoms, both in clinical and healthy populations of children, are lacking. The current study sought to explore these relationships by investigating whether trait-like and/or daily reports of affective and somatic symptoms of children with generalized anxiety disorder and matched controls relate to sleep architecture. Sixty-six children (ages 7-11; 54.4% female; 56.1% Caucasian; 18.2% biracial; 6.1% African American; 3% Asian; 16.7% Hispanic) participated including 29 with primary generalized anxiety disorder (without comorbid depression) and 37 healthy controls matched on age and race/ethnicity. Participants underwent structured diagnostic assessments including child-report measures and subsequently reported on their negative affect and somatic symptoms over the course of 1 week. Children also completed 1 night of polysomnography. Among children with generalized anxiety disorder only, greater amounts of slow wave sleep corresponded with less negative affect, and greater amounts of rapid eye movement sleep was related to more somatic complaints across the week. Similarly, for trait-like measures, more rapid eye movement sleep and shorter latency to rapid eye movement sleep were related to greater depressive symptoms in the anxious group only. The current findings suggest that physiologic sleep characteristics may contribute in direct ways to the symptom profiles of clinically anxious children. The functional relevance of such findings (e.g., how specific sleep characteristics serve to either increase or reduce long-term risk) is a vital direction for future research.

Extending a prototype knowledge- and object-based image analysis model to coarser spatial resolution imagery: an example from the Missouri River

USGS Publications Warehouse

Strong, Laurence L.

2012-01-01

A prototype knowledge- and object-based image analysis model was developed to inventory and map least tern and piping plover habitat on the Missouri River, USA. The model has been used to inventory the state of sandbars annually for 4 segments of the Missouri River since 2006 using QuickBird imagery. Interpretation of the state of sandbars is difficult when images for the segment are acquired at different river stages and different states of vegetation phenology and canopy cover. Concurrent QuickBird and RapidEye images were classified using the model and the spatial correspondence of classes in the land cover and sandbar maps were analysed for the spatial extent of the images and at nest locations for both bird species. Omission and commission errors were low for unvegetated land cover classes used for nesting by both bird species and for land cover types with continuous vegetation cover and water. Errors were larger for land cover classes characterized by a mixture of sand and vegetation. Sandbar classification decisions are made using information on land cover class proportions and disagreement between sandbar classes was resolved using fuzzy membership possibilities. Regression analysis of area for a paired sample of 47 sandbars indicated an average positive bias, 1.15 ha, for RapidEye that did not vary with sandbar size. RapidEye has potential to reduce temporal uncertainty about least tern and piping plover habitat but would not be suitable for mapping sandbar erosion, and characterization of sandbar shapes or vegetation patches at fine spatial resolution.

Extending a prototype knowledge and object based image analysis model to coarser spatial resolution imagery: an example from the Missouri River

USGS Publications Warehouse

Strong, Laurence L.

2012-01-01

A prototype knowledge- and object-based image analysis model was developed to inventory and map least tern and piping plover habitat on the Missouri River, USA. The model has been used to inventory the state of sandbars annually for 4 segments of the Missouri River since 2006 using QuickBird imagery. Interpretation of the state of sandbars is difficult when images for the segment are acquired at different river stages and different states of vegetation phenology and canopy cover. Concurrent QuickBird and RapidEye images were classified using the model and the spatial correspondence of classes in the land cover and sandbar maps were analysed for the spatial extent of the images and at nest locations for both bird species. Omission and commission errors were low for unvegetated land cover classes used for nesting by both bird species and for land cover types with continuous vegetation cover and water. Errors were larger for land cover classes characterized by a mixture of sand and vegetation. Sandbar classification decisions are made using information on land cover class proportions and disagreement between sandbar classes was resolved using fuzzy membership possibilities. Regression analysis of area for a paired sample of 47 sandbars indicated an average positive bias, 1.15 ha, for RapidEye that did not vary with sandbar size. RapidEye has potential to reduce temporal uncertainty about least tern and piping plover habitat but would not be suitable for mapping sandbar erosion, and characterization of sandbar shapes or vegetation patches at fine spatial resolution.

Features of the Retinotopic Representation in the Visual Wulst of a Laterally Eyed Bird, the Zebra Finch (Taeniopygia guttata)

PubMed Central

Michael, Neethu; Löwel, Siegrid; Bischof, Hans-Joachim

2015-01-01

The visual wulst of the zebra finch comprises at least two retinotopic maps of the contralateral eye. As yet, it is not known how much of the visual field is represented in the wulst neuronal maps, how the organization of the maps is related to the retinal architecture, and how information from the ipsilateral eye is involved in the activation of the wulst. Here, we have used autofluorescent flavoprotein imaging and classical anatomical methods to investigate such characteristics of the most posterior map of the multiple retinotopic representations. We found that the visual wulst can be activated by visual stimuli from a large part of the visual field of the contralateral eye. Horizontally, the visual field representation extended from -5° beyond the beak tip up to +125° laterally. Vertically, a small strip from -10° below to about +25° above the horizon activated the visual wulst. Although retinal ganglion cells had a much higher density around the fovea and along a strip extending from the fovea towards the beak tip, these areas were not overrepresented in the wulst map. The wulst area activated from the foveal region of the ipsilateral eye, overlapped substantially with the middle of the three contralaterally activated regions in the visual wulst, and partially with the other two. Visual wulst activity evoked by stimulation of the frontal visual field was stronger with contralateral than with binocular stimulation. This confirms earlier electrophysiological studies indicating an inhibitory influence of the activation of the ipsilateral eye on wulst activity elicited by stimulating the contralateral eye. The lack of a foveal overrepresentation suggests that identification of objects may not be the primary task of the zebra finch visual wulst. Instead, this brain area may be involved in the processing of visual information necessary for spatial orientation. PMID:25853253

Validation of mobile eye-tracking as novel and efficient means for differentiating progressive supranuclear palsy from Parkinson's disease

PubMed Central

Marx, Svenja; Respondek, Gesine; Stamelou, Maria; Dowiasch, Stefan; Stoll, Josef; Bremmer, Frank; Oertel, Wolfgang H.; Höglinger, Günter U.; Einhäuser, Wolfgang

2012-01-01

Background: The decreased ability to carry out vertical saccades is a key symptom of Progressive Supranuclear Palsy (PSP). Objective measurement devices can help to reliably detect subtle eye movement disturbances to improve sensitivity and specificity of the clinical diagnosis. The present study aims at transferring findings from restricted stationary video-oculography (VOG) to a wearable head-mounted device, which can be readily applied in clinical practice. Methods: We investigated the eye movements in 10 possible or probable PSP patients, 11 Parkinson's disease (PD) patients, and 10 age-matched healthy controls (HCs) using a mobile, gaze-driven video camera setup (EyeSeeCam). Ocular movements were analyzed during a standardized fixation protocol and in an unrestricted real-life scenario while walking along a corridor. Results: The EyeSeeCam detected prominent impairment of both saccade velocity and amplitude in PSP patients, differentiating them from PD and HCs. Differences were particularly evident for saccades in the vertical plane, and stronger for saccades than for other eye movements. Differences were more pronounced during the standardized protocol than in the real-life scenario. Conclusions: Combined analysis of saccade velocity and saccade amplitude during the fixation protocol with the EyeSeeCam provides a simple, rapid (<20 s), and reliable tool to differentiate clinically established PSP patients from PD and HCs. As such, our findings prepare the ground for using wearable eye-tracking in patients with uncertain diagnoses. PMID:23248593

Decoding of intended saccade direction in an oculomotor brain-computer interface

NASA Astrophysics Data System (ADS)

Jia, Nan; Brincat, Scott L.; Salazar-Gómez, Andrés F.; Panko, Mikhail; Guenther, Frank H.; Miller, Earl K.

2017-08-01

Objective. To date, invasive brain-computer interface (BCI) research has largely focused on replacing lost limb functions using signals from the hand/arm areas of motor cortex. However, the oculomotor system may be better suited to BCI applications involving rapid serial selection from spatial targets, such as choosing from a set of possible words displayed on a computer screen in an augmentative and alternative communication (AAC) application. Here we aimed to demonstrate the feasibility of a BCI utilizing the oculomotor system. Approach. We developed a chronic intracortical BCI in monkeys to decode intended saccadic eye movement direction using activity from multiple frontal cortical areas. Main results. Intended saccade direction could be decoded in real time with high accuracy, particularly at contralateral locations. Accurate decoding was evident even at the beginning of the BCI session; no extensive BCI experience was necessary. High-frequency (80-500 Hz) local field potential magnitude provided the best performance, even over spiking activity, thus simplifying future BCI applications. Most of the information came from the frontal and supplementary eye fields, with relatively little contribution from dorsolateral prefrontal cortex. Significance. Our results support the feasibility of high-accuracy intracortical oculomotor BCIs that require little or no practice to operate and may be ideally suited for ‘point and click’ computer operation as used in most current AAC systems.

Orienting Auditory Spatial Attention Engages Frontal Eye Fields and Medial Occipital Cortex in Congenitally Blind Humans

PubMed Central

Garg, Arun; Schwartz, Daniel; Stevens, Alexander A.

2007-01-01

What happens in vision related cortical areas when congenitally blind (CB) individuals orient attention to spatial locations? Previous neuroimaging of sighted individuals has found overlapping activation in a network of frontoparietal areas including frontal eye-fields (FEF), during both overt (with eye movement) and covert (without eye movement) shifts of spatial attention. Since voluntary eye movement planning seems irrelevant in CB, their FEF neurons should be recruited for alternative functions if their attentional role in sighted individuals is only due to eye movement planning. Recent neuroimaging of the blind has also reported activation in medial occipital areas, normally associated with visual processing, during a diverse set of non-visual tasks, but their response to attentional shifts remains poorly understood. Here, we used event-related fMRI to explore FEF and medial occipital areas in CB individuals and sighted controls with eyes closed (SC) performing a covert attention orienting task, using endogenous verbal cues and spatialized auditory targets. We found robust stimulus-locked FEF activation of all CB subjects, similar but stronger than in SC, suggesting that FEF plays a role in endogenous orienting of covert spatial attention even in individuals in whom voluntary eye movements are irrelevant. We also found robust activation in bilateral medial occipital cortex in CB but not in SC subjects. The response decreased below baseline following endogenous verbal cues but increased following auditory targets, suggesting that the medial occipital area in CB does not directly engage during cued orienting of attention but may be recruited for processing of spatialized auditory targets. PMID:17397882

Preservation of Biological Activity of Plasma and Platelet-Derived Eye Drops After Their Different Time and Temperature Conditions of Storage.

PubMed

Anitua, Eduardo; de la Fuente, María; Riestra, Ana; Merayo-Lloves, Jesús; Muruzábal, Francisco; Orive, Gorka

2015-09-01

To analyze whether plasma rich in growth factors (PRGF) eye drops preserve their biological characteristics and activity after storage for 3 and 6 months at -20°C, at 4°C, and at room temperature for 72 hours, compared with fresh samples (t0). Blood from 6 healthy donors was harvested and centrifuged to obtain PRGF free of leukocytes. Resulting PRGF eye drops were stored for 3 and 6 months at -20°C. At each time, 2 aliquots were maintained at room temperature or at 4°C for 72 hours. Platelet-derived growth factor-AB, transforming growth factor-β1, vascular endothelial growth factor, epidermal growth factor, insulin-like growth factor-1, angiopoietin-1, and thrombospondin-1 were quantified at each time and temperature of storage. Also, the effect of PRGF eye drops on proliferation of primary human keratocytes was evaluated. All the analyzed growth factor levels remained constant at each time and storage condition. No differences were observed in the proliferative activity of keratocytes after treatment with PRGF eye drops at any studied time or temperature. Finally, there was no microbial contamination in any of the PRGF eye drops. The preservation of the PRGF eye drops at -20°C for up to 3 and 6 months does not mean reduction of the main growth factors and proteins implicated in ocular surface wound healing. Eye drop characteristics and in vitro biological activity were not affected by their usage and conservation for 72 hours at 4°C or at room temperature.

Sleep and Wakefulness Handbook for Flight Medical Officers,

DTIC Science & Technology

1982-01-01

hours, but routine monotonous tasks show a rapid and severe decrement after 24 hours without sleep. Motivation may counteract some of the sequelae of...repeated partial sleep loss will lead to impaired performance. IRREGULARITY OF WORK AND REST Irregularity of work and rest over several days is also...movements, each of several seconds duration, which are usually most prominent during the early part of the stage. Rapid eye movements are absent, and the

A phenolic acid based colourimetric 'naked-eye' chemosensor for the rapid detection of Cu(II) ions

NASA Astrophysics Data System (ADS)

Sengupta, Priti; Ganguly, Aniruddha; Bose, Adity

2018-06-01

The crucial role of chemosensor for the immediate recognition of environment pollutant motivates the researchers to develop variety of sensing protocols. Of various chemosensory protocols, the colour change observed by the naked eye is considered to be a conceivable and on-site way to indicate the presence of an analyte. We herein report a colourimetric and commercially available absorption probe, sinapic acid (SA) that is completely ready to use for "on-site" visual determination of copper ions. The molecule, SA is well-known phenolic acid, often utilized for its antibacterial activity. In this work, for the first time, we are exploring its ability to work as an efficient Cu2+ sensor. This sensor molecule selectively detected Cu2+ ions by changing its colour from colourless to pink within detection limit of 64.5 nM, which is much lower than other reported sensor molecules and the suggested limit by World Health Organization (WHO) and U. S. Environmental Protection Agency (EPA) guidelines. The sensing mechanism was investigated through UV-vis and 1H NMR titration along with ESI-MS spectroscopy and further confirmed by DFT computational studies. Studies revealed the participation of hydroxyl group (sbnd OH) and methoxy group (sbnd OMe) of SA in complexation with Cu2+. The binding stoichiometry of SA to Cu2+ was found to be 1:2 through Job's plot and ESI-MS analysis. Importantly, paper strips of SA were prepared which could be used for a rapid "on-site" determination of Cu2+ containing samples.

Re-presentation of Olfactory Exposure Therapy Success Cues during Non-Rapid Eye Movement Sleep did not Increase Therapy Outcome but Increased Sleep Spindles

PubMed Central

Rihm, Julia S.; Sollberger, Silja B.; Soravia, Leila M.; Rasch, Björn

2016-01-01

Exposure therapy induces extinction learning and is an effective treatment for specific phobias. Sleep after learning promotes extinction memory and benefits therapy success. As sleep-dependent memory-enhancing effects are based on memory reactivations during sleep, here we aimed at applying the beneficial effect of sleep on therapy success by cueing memories of subjective therapy success during non-rapid eye movement sleep after in vivo exposure-based group therapy for spider phobia. In addition, oscillatory correlates of re-presentation during sleep (i.e., sleep spindles and slow oscillations) were investigated. After exposure therapy, spider-phobic patients verbalized their subjectively experienced therapy success under presence of a contextual odor. Then, patients napped for 90 min recorded by polysomnography. Half of the sleep group received the odor during sleep while the other half was presented an odorless vehicle as control. A third group served as a wake control group without odor presentation. While exposure therapy significantly reduced spider-phobic symptoms in all subjects, these symptoms could not be further reduced by re-presenting the odor associated with therapy success, probably due to a ceiling effect of the highly effective exposure therapy. However, odor re-exposure during sleep increased left-lateralized frontal slow spindle (11.0–13.0 Hz) and right-lateralized parietal fast spindle (13.0–15.0 Hz) activity, suggesting the possibility of a successful re-presentation of therapy-related memories during sleep. Future studies need to further examine the possibility to enhance therapy success by targeted memory reactivation (TMR) during sleep. PMID:27445775

Sleep/Wake Physiology and Quantitative Electroencephalogram Analysis of the Neuroligin-3 Knockout Rat Model of Autism Spectrum Disorder.

PubMed

Thomas, Alexia M; Schwartz, Michael D; Saxe, Michael D; Kilduff, Thomas S

2017-10-01

Neuroligin-3 (NLGN3) is one of the many genes associated with autism spectrum disorder (ASD). Sleep dysfunction is highly prevalent in ASD, but has not been rigorously examined in ASD models. Here, we evaluated sleep/wake physiology and behavioral phenotypes of rats with genetic ablation of Nlgn3. Male Nlgn3 knockout (KO) and wild-type (WT) rats were assessed using a test battery for ASD-related behaviors and also implanted with telemeters to record the electroencephalogram (EEG), electromyogram, body temperature, and locomotor activity. 24-h EEG recordings were analyzed for sleep/wake states and spectral composition. Nlgn3 KO rats were hyperactive, exhibited excessive chewing behavior, and had impaired prepulse inhibition to an auditory startle stimulus. KO rats also spent less time in non-rapid eye movement (NREM) sleep, more time in rapid eye movement (REM) sleep, exhibited elevated theta power (4-9 Hz) during wakefulness and REM, and elevated delta power (0.5-4 Hz) during NREM. Beta (12-30 Hz) power and gamma (30-50 Hz) power were suppressed across all vigilance states. The sleep disruptions in Nlgn3 KO rats are consistent with observations of sleep disturbances in ASD patients. The EEG provides objective measures of brain function to complement rodent behavioral analyses and therefore may be a useful tool to study ASD. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Quantitative EEG of Rapid-Eye-Movement Sleep: A Marker of Amnestic Mild Cognitive Impairment.

PubMed

Brayet, Pauline; Petit, Dominique; Frauscher, Birgit; Gagnon, Jean-François; Gosselin, Nadia; Gagnon, Katia; Rouleau, Isabelle; Montplaisir, Jacques

2016-04-01

The basal forebrain cholinergic system, which is impaired in early Alzheimer's disease, is more crucial for the activation of rapid-eye-movement (REM) sleep electroencephalogram (EEG) than it is for wakefulness. Quantitative EEG from REM sleep might thus provide an earlier and more accurate marker of the development of Alzheimer's disease in subjects with mild cognitive impairment (MCI) subjects than that from wakefulness. To assess the superiority of the REM sleep EEG as a screening tool for preclinical Alzheimer's disease, 22 subjects with amnestic MCI (a-MCI; 63.9±7.7 years), 10 subjects with nonamnestic MCI (na-MCI; 64.1±4.5 years) and 32 controls (63.7±6.6 years) participated in the study. Spectral analyses of the waking EEG and REM sleep EEG were performed and the [(delta+theta)/(alpha+beta)] ratio was used to assess between-group differences in EEG slowing. The a-MCI subgroup showed EEG slowing in frontal lateral regions compared to both na-MCI and control groups. This EEG slowing was present in wakefulness (compared to controls) but was much more prominent in REM sleep. Moreover, the comparison between amnestic and nonamnestic subjects was found significant only for the REM sleep EEG. There was no difference in EEG power ratio between na-MCI and controls for any of the 7 cortical regions studied. These findings demonstrate the superiority of the REM sleep EEG in the discrimination between a-MCI and both na-MCI and control subjects. © EEG and Clinical Neuroscience Society (ECNS) 2015.

Different Simultaneous Sleep States in the Hippocampus and Neocortex.

PubMed

Emrick, Joshua J; Gross, Brooks A; Riley, Brett T; Poe, Gina R

2016-12-01

Investigators assign sleep-waking states using brain activity collected from a single site, with the assumption that states occur at the same time throughout the brain. We sought to determine if sleep-waking states differ between two separate structures: the hippocampus and neocortex. We measured electrical signals (electroencephalograms and electromyograms) during sleep from the hippocampus and neocortex of five freely behaving adult male rats. We assigned sleep-waking states in 10-sec epochs based on standard scoring criteria across a 4-h recording, then analyzed and compared states and signals from simultaneous epochs between sites. We found that the total amount of each state, assigned independently using the hippocampal and neocortical signals, was similar between the hippocampus and neocortex. However, states at simultaneous epochs were different as often as they were the same (P = 0.82). Furthermore, we found that the progression of states often flowed through asynchronous state-pairs led by the hippocampus. For example, the hippocampus progressed from transition-to-rapid eye movement sleep to rapid eye movement sleep before the neocortex more often than in synchrony with the neocortex (38.7 ± 16.2% versus 15.8 ± 5.6% mean ± standard error of the mean). We demonstrate that hippocampal and neocortical sleep-waking states often differ in the same epoch. Consequently, electrode location affects estimates of sleep architecture, state transition timing, and perhaps even percentage of time in sleep states. Therefore, under normal conditions, models assuming brain state homogeneity should not be applied to the sleeping or waking brain. © 2016 Associated Professional Sleep Societies, LLC.

Sleep Spindles and Intellectual Ability: Epiphenomenon or Directly Related?

PubMed

Fang, Zhuo; Sergeeva, Valya; Ray, Laura B; Viczko, Jeremy; Owen, Adrian M; Fogel, Stuart M

2017-01-01

Sleep spindles-short, phasic, oscillatory bursts of activity that characterize non-rapid eye movement sleep-are one of the only electrophysiological oscillations identified as a biological marker of human intelligence (e.g., cognitive abilities commonly assessed using intelligence quotient tests). However, spindles are also important for sleep maintenance and are modulated by circadian factors. Thus, the possibility remains that the relationship between spindles and intelligence quotient may be an epiphenomenon of a putative relationship between good quality sleep and cognitive ability or perhaps modulated by circadian factors such as morningness-eveningness tendencies. We sought to ascertain whether spindles are directly or indirectly related to cognitive abilities using mediation analysis. Here, we show that fast (13.5-16 Hz) parietal but not slow (11-13.5 Hz) frontal spindles in both non-rapid eye movement stage 2 sleep and slow wave sleep are directly related to reasoning abilities (i.e., cognitive abilities that support "fluid intelligence," such as the capacity to identify complex patterns and relationships and the use of logic to solve novel problems) but not verbal abilities (i.e., cognitive abilities that support "crystalized intelligence"; accumulated knowledge and experience) or cognitive abilities that support STM (i.e., the capacity to briefly maintain information in an available state). The relationship between fast spindles and reasoning abilities is independent of the indicators of sleep maintenance and circadian chronotype, thus suggesting that spindles are indeed a biological marker of cognitive abilities and can serve as a window to further explore the physiological and biological substrates that give rise to human intelligence.

Automatic characterization of sleep need dissipation dynamics using a single EEG signal.

PubMed

Garcia-Molina, Gary; Bellesi, Michele; Riedner, Brady; Pastoor, Sander; Pfundtner, Stefan; Tononi, Giulio

2015-01-01

In the two-process model of sleep regulation, slow-wave activity (SWA, i.e. the EEG power in the 0.5-4 Hz frequency band) is considered a direct indicator of sleep need. SWA builds up during non-rapid eye movement (NREM) sleep, declines before the onset of rapid-eye-movement (REM) sleep, remains low during REM and the level of increase in successive NREM episodes gets progressively lower. Sleep need dissipates with a speed that is proportional to SWA and can be characterized in terms of the initial sleep need, and the decay rate. The goal in this paper is to automatically characterize sleep need from a single EEG signal acquired at a frontal location. To achieve this, a highly specific and reasonably sensitive NREM detection algorithm is proposed that leverages the concept of a single-class Kernel-based classifier. Using automatic NREM detection, we propose a method to estimate the decay rate and the initial sleep need. This method was tested on experimental data from 8 subjects who recorded EEG during three nights at home. We found that on average the estimates of the decay rate and the initial sleep need have higher values when automatic NREM detection was used as compared to manual NREM annotation. However, the average variability of these estimates across multiple nights of the same subject was lower when the automatic NREM detection classifier was used. While this method slightly over estimates the sleep need parameters, the reduced variability across subjects makes it more effective for within subject statistical comparisons of a given sleep intervention.

Sleep and behavior during vesicular stomatitis virus induced encephalitis in BALB/cJ and C57BL/6J mice

PubMed Central

Machida, Mayumi; Ambrozewicz, Marta A.; Breving, Kimberly; Wellman, Laurie L.; Yang, Linghui; Ciavarra, Richard P.; Sanford, Larry D.

2013-01-01

Intranasal application of vesicular stomatitis virus (VSV) produces a well-characterized model of viral encephalitis in mice. Within one day post-infection (PI), VSV travels to the olfactory bulb and, over the course of 7 days, it infects regions and tracts extending into the brainstem followed by clearance and recovery in most mice by PI day 14 (PI 14). Infectious diseases are commonly accompanied by excessive sleepiness; thus, sleep is considered a component of the acute phase response to infection. In this project, we studied the relationship between sleep and VSV infection using C57BL/6 (B6) and BALB/c mice. Mice were implanted with transmitters for recording EEG, activity and temperature by telemetry. After uninterrupted baseline recordings were collected for 2 days, each animal was infected intranasally with a single low dose of VSV (5 × 104 PFU). Sleep was recorded for 15 consecutive days and analyzed on PI 0, 1, 3, 5, 7, 10, and 14. Compared to baseline, amounts of non-rapid eye movement sleep (NREM) were increased in B6 mice during the dark period of PI 1–5, whereas rapid eye movement sleep (REM) was significantly reduced during the light periods of PI 0–14. In contrast, BALB/c mice showed significantly fewer changes in NREM and REM. These data demonstrate sleep architecture is differentially altered in these mouse strains and suggests that, in B6 mice, VSV can alter sleep before virus progresses into brain regions that control sleep. PMID:24055862

A phenolic acid based colourimetric 'naked-eye' chemosensor for the rapid detection of Cu(II) ions.

PubMed

Sengupta, Priti; Ganguly, Aniruddha; Bose, Adity

2018-06-05

The crucial role of chemosensor for the immediate recognition of environment pollutant motivates the researchers to develop variety of sensing protocols. Of various chemosensory protocols, the colour change observed by the naked eye is considered to be a conceivable and on-site way to indicate the presence of an analyte. We herein report a colourimetric and commercially available absorption probe, sinapic acid (SA) that is completely ready to use for "on-site" visual determination of copper ions. The molecule, SA is well-known phenolic acid, often utilized for its antibacterial activity. In this work, for the first time, we are exploring its ability to work as an efficient Cu 2+ sensor. This sensor molecule selectively detected Cu 2+ ions by changing its colour from colourless to pink within detection limit of 64.5nM, which is much lower than other reported sensor molecules and the suggested limit by World Health Organization (WHO) and U. S. Environmental Protection Agency (EPA) guidelines. The sensing mechanism was investigated through UV-vis and 1 H NMR titration along with ESI-MS spectroscopy and further confirmed by DFT computational studies. Studies revealed the participation of hydroxyl group (OH) and methoxy group (OMe) of SA in complexation with Cu 2+ . The binding stoichiometry of SA to Cu 2+ was found to be 1:2 through Job's plot and ESI-MS analysis. Importantly, paper strips of SA were prepared which could be used for a rapid "on-site" determination of Cu 2+ containing samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Antioxidant and inflammatory cytokine in tears of patients with dry eye syndrome treated with preservative-free versus preserved eye drops.

PubMed

Jee, Donghyun; Park, Sang Hee; Kim, Man Soo; Kim, Eun Chul

2014-07-03

To compare the antioxidant and inflammatory cytokine activities in tears of patients with dry eye syndrome treated with preservative-free versus preserved eye drops. A total of 100 patients with moderate to severe dry eye syndrome were randomly divided into two groups. Fifty patients (group 1) were treated four times with preservative-free 0.1% sodium hyaluronate and 0.1% fluorometholone eye drops in the first month and with preservative-free 0.1% sodium hyaluronate and 0.05% cyclosporine eye drops in the second and third months. Another 50 patients (group 2) were treated with preserved eye drops on the same schedule. Ocular Surface Disease Index, corneal fluorescein staining, Schirmer I test, tear film breakup time, impression cytology, and antioxidant and inflammatory cytokine activities in tears were evaluated. Treatment with preservative-free eye drops led to significant improvements in symptoms, tear film breakup time, Schirmer I score, and impression cytologic findings compared to treatment with preserved eye drops (P < 0.05) in patients with dry eye syndrome. There was a statistically significant decrease in the IL-1β, IL-6, IL-12, and TNF-α concentrations and a statistically significant increase in the catalase, peroxiredoxin 2, superoxide dismutase 2 (SOD 2), and thioredoxin mean fluorescence intensity (MFI) of tears in the preservative-free group at 1, 2, and 3 months compared to initial values, respectively (P < 0.05). Treatment with preservative-free eye drops is effective against the dry eye syndrome. Preservative-free eye drops seem to be more effective than preserved eye drops in decreasing ocular inflammation and in increasing antioxidant contents in tears of patients with dry eye syndrome. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Ponto-geniculo-occipital-wave suppression amplifies lateral geniculate nucleus cell-size changes in monocularly deprived kittens.

PubMed

Shaffery, J P; Roffwarg, H P; Speciale, S G; Marks, G A

1999-04-12

We have previously shown that during the post-natal critical period of development of the cat visual system, 1 week of instrumental rapid eye movement (REM) sleep deprivation (IRSD) during 2 weeks of monocular deprivation (MD) results in significant amplification of the effects of solely the 2-week MD on cell-size in the binocular segment of the lateral geniculate nucleus (LGN) [36,40]. In this study, we examined whether elimination of ponto-geniculo-occipital (PGO)-wave phasic activity in the LGN during REM sleep (REMS), rather than suppression of all REMS state-related activity, would similarly yield enhanced plasticity effects on cell-size in LGN. PGO-activity was eliminated in LGN by bilateral pontomesencephalic lesions [8,32]. This method of removing phasic activation at the level of the LGN preserved sleep and wake proportions as well as the tonic activities (low voltage, fast frequency ECoG and low amplitude EMG) that characterize REM sleep. The lesions were performed in kittens on post-natal day 42, at the end of the first week of the 2-week period of MD, the same age when IRSD was started in the earlier study. LGN interlaminar cell-size disparity increased in the PGO-wave-suppressed animals as it had in behaviorally REM sleep-deprived animals. Smaller A1/A-interlaminar ratios reflect the increased disparity effect in both the REM sleep- and PGO-suppressed groups compared to animals subjected to MD-alone. With IRSD, the effect was achieved because the occluded eye-related, LGN A1-lamina cells tended to be smaller relative to their size after MD-alone, whereas after PGO-suppressing lesions, the A1-lamina cells retained their size and the non-occluded eye-related, A-lamina cells tended to be larger than after MD-alone. Despite this difference, for which several possible explanations are offered, these A1/A-interlaminar ratio data indicate that in conjunction either with suppression of the whole of the REMS state or selective removal of REM sleep phasic activity at the LGN, altered visual input evokes more LGN cell plasticity during the developmental period than it would otherwise. These data further support involvement of the REM sleep state in reducing susceptibility to plasticity changes and undesirable variability in the course of normative CNS growth and maturation. Copyright 1999 Elsevier Science B.V.

Co-activated yet disconnected-Neural correlates of eye closures when trying to stay awake.

PubMed

Ong, Ju Lynn; Kong, Danyang; Chia, Tiffany T Y; Tandi, Jesisca; Thomas Yeo, B T; Chee, Michael W L

2015-09-01

Spontaneous eye-closures that herald sleep onset become more frequent when we are sleep deprived. Although these are typically associated with decreased responsiveness to external stimuli, it is less clear what occurs in the brain at these transitions to drowsiness and light sleep. To investigate this, task-free fMRI of sleep-deprived participants was acquired. BOLD activity associated with periods of spontaneously occurring eye closures were marked and analyzed. We observed concurrent and extensive hypnagogic co-activation of the extrastriate visual, auditory, and somatosensory cortices as well as the default mode network, consistent with internal sensory activity without external stimulation. Co-activation of fronto-parietal areas known to mediate attentional control could correspond with participants resisting sleep or additional engagement of mental imagery. This constellation of signal changes differed from those elicited by cued eye closures of similar duration and distribution in the same, rested participants. They also differ from signal changes associated with mind-wandering and consolidated light sleep. Concurrent with the observed event-related changes, eye closures elicited additional reduction in functional connectivity within nodes of the DMN and DAN, superposed on already reduced connectivity associated with sleep deprivation. There was concurrent deactivation of the thalamus during eye-closure during the sleep-deprived state but almost similar changes occurred in the well-rested state that may also be relevant. These findings highlight the dynamic shifts in brain activity and connectivity at border between wakefulness and sleep. Copyright © 2015. Published by Elsevier Inc.

Relations between age, weight, refractive error and eye shape by computerized tomography in children.

PubMed

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung; Moon, Yeon Sung

2007-09-01

To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths/axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years.

Relations between Age, Weight, Refractive Error and Eye Shape by Computerized Tomography in Children

PubMed Central

Song, Ha Tae; Kim, Young Jun; Lee, Soo Jung

2007-01-01

Purpose To investigate relationships between age, weight, refractive error, and morphologic changes in children's eyes by computerized tomography (CT). Methods Of the 772 eyes of 386 patients under the age of 20 years, who visited our Department of Ophthalmology between January 2005 to August 2006 and underwent CT of the orbit, 406 eyes of 354 patients with clear CT images and normal eyeball contour were enrolled in the present retrospective study. The axial lengths, widths, horizontal and vertical lengths, refractive errors, and body weight of eyes were measured, and relationship between these parameters were investigated. Results Axial length was found to correlate significantly with eye width (r=0.914), and in emmetropic eyes and myopic eyes, axial lengths and widths were found to increase as age and body weight increased. Axial lengths increased rapidly until age 10, and then increased slowly. In emmetropic eyes, widths / axial lengths increased with age, but in myopic eyes these decreased as age or severity of myopia increased. Moreover, as age increased, the myopic population and severity also increased. Conclusions The axial length was longer in case of myopia compared to emmetropia in all age groups and there was almost no difference in the increase rate of axial length by the age of myopia and emmetropia. However, the width was wider in case of myopia compared to emmetropia in all age groups and the increase rate of width in myopia by age was smaller than that of emmetropia. Myopia showed decreasing rate of width/axial length with increase of age, from 1.004 in 5 years to 0.971 in 20 years. However, emmetropia showed increasing rate of width/axial length with increase of age, from 0.990 in 5 years to 1.006 in 20 years. PMID:17804923

21 CFR 500.65 - Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of...

Code of Federal Regulations, 2011 CFR

2011-04-01

... symptoms of anaphylactoid shock including glassy eyes, increased salivation, grinding of the teeth, rapid... treating anaphylactoid shock. Usual Dosage: Cattle, horses, sheep, and swine—1 cubic centimeter per 100...

21 CFR 500.65 - Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of...

Code of Federal Regulations, 2010 CFR

2010-04-01

... symptoms of anaphylactoid shock including glassy eyes, increased salivation, grinding of the teeth, rapid... treating anaphylactoid shock. Usual Dosage: Cattle, horses, sheep, and swine—1 cubic centimeter per 100...

High-speed adaptive optics line scan confocal retinal imaging for human eye

PubMed Central

Wang, Xiaolin; Zhang, Yuhua

2017-01-01

Purpose Continuous and rapid eye movement causes significant intraframe distortion in adaptive optics high resolution retinal imaging. To minimize this artifact, we developed a high speed adaptive optics line scan confocal retinal imaging system. Methods A high speed line camera was employed to acquire retinal image and custom adaptive optics was developed to compensate the wave aberration of the human eye’s optics. The spatial resolution and signal to noise ratio were assessed in model eye and in living human eye. The improvement of imaging fidelity was estimated by reduction of intra-frame distortion of retinal images acquired in the living human eyes with frame rates at 30 frames/second (FPS), 100 FPS, and 200 FPS. Results The device produced retinal image with cellular level resolution at 200 FPS with a digitization of 512×512 pixels/frame in the living human eye. Cone photoreceptors in the central fovea and rod photoreceptors near the fovea were resolved in three human subjects in normal chorioretinal health. Compared with retinal images acquired at 30 FPS, the intra-frame distortion in images taken at 200 FPS was reduced by 50.9% to 79.7%. Conclusions We demonstrated the feasibility of acquiring high resolution retinal images in the living human eye at a speed that minimizes retinal motion artifact. This device may facilitate research involving subjects with nystagmus or unsteady fixation due to central vision loss. PMID:28257458

Efficacy of Eye Movement Desensitization in the treatment of cognitive intrusions related to a past stressful event.

PubMed

Lytle, Richard A; Hazlett-Stevens, Holly; Borkovec, T D

2002-01-01

Much of the Eye Movement Desensitization and Reprocessing (EMDR) efficacy research has been widely criticized, limiting scientific understanding of its therapeutic components. The present investigation of Eye Movement Desensitization (EMD) effectiveness included undergraduate students reporting current intrusive cognitions conceming a traumatic event. Forty-five participants received a single treatment session of either: (a) EMD, as described by Shapiro [J. Behav. Ther. Exp. Psychiatry 20 (1989b) 211], (b) an identical procedure which employed eye fixation on a stationary target, or (c) non-directive counseling. Standardized self-report, subjective rating, Daily Diary, and intrusive thought sampling measures were collected before and after treatment. Results indicated that participants in the eye fixation group reported marginally (p < .052) fewer cognitive intrusions than the non-directive group 1 week following treatment. No significant differences between the EMD and non-directive conditions or between the EMD and eye fixation conditions on this measure were found. During the treatment session, both desensitization groups were superior to the non-directive group in reducing reported vividness of the mental image of the original event. However, the non-directive group improved to the level of the two other groups by the following week. Rapid saccadic eye movements were therefore unrelated to immediate treatment effects for this sub-clinical sample, and non-directive treatment largely yielded eventual outcomes equivalent to the two desensitization conditions.

Design and synthesis of target-responsive hydrogel for portable visual quantitative detection of uranium with a microfluidic distance-based readout device.

PubMed

Huang, Yishun; Fang, Luting; Zhu, Zhi; Ma, Yanli; Zhou, Leiji; Chen, Xi; Xu, Dunming; Yang, Chaoyong

2016-11-15

Due to uranium's increasing exploitation in nuclear energy and its toxicity to human health, it is of great significance to detect uranium contamination. In particular, development of a rapid, sensitive and portable method is important for personal health care for those who frequently come into contact with uranium ore mining or who investigate leaks at nuclear power plants. The most stable form of uranium in water is uranyl ion (UO2(2+)). In this work, a UO2(2+) responsive smart hydrogel was designed and synthesized for rapid, portable, sensitive detection of UO2(2+). A UO2(2+) dependent DNAzyme complex composed of substrate strand and enzyme strand was utilized to crosslink DNA-grafted polyacrylamide chains to form a DNA hydrogel. Colorimetric analysis was achieved by encapsulating gold nanoparticles (AuNPs) in the DNAzyme-crosslinked hydrogel to indicate the concentration of UO2(2+). Without UO2(2+), the enzyme strand is not active. The presence of UO2(2+) in the sample activates the enzyme strand and triggers the cleavage of the substrate strand from the enzyme strand, thereby decreasing the density of crosslinkers and destabilizing the hydrogel, which then releases the encapsulated AuNPs. As low as 100nM UO2(2+) was visually detected by the naked eye. The target-responsive hydrogel was also demonstrated to be applicable in natural water spiked with UO2(2+). Furthermore, to avoid the visual errors caused by naked eye observation, a previously developed volumetric bar-chart chip (V-Chip) was used to quantitatively detect UO2(2+) concentrations in water by encapsulating Au-Pt nanoparticles in the hydrogel. The UO2(2+) concentrations were visually quantified from the travelling distance of ink-bar on the V-Chip. The method can be used for portable and quantitative detection of uranium in field applications without skilled operators and sophisticated instruments. Copyright © 2016 Elsevier B.V. All rights reserved.

Genetic Evidence for a Role for Protein Kinase A in the Maintenance of Sleep and Thalamocortical Oscillations

PubMed Central

Hellman, Kevin; Hernandez, Pepe; Park, Alice; Abel, Ted

2010-01-01

Study Objectives: Genetic manipulation of cAMP-dependent protein kinase A (PKA) in Drosophila has implicated an important role for PKA in sleep/wake state regulation. Here, we characterize the role of this signaling pathway in the regulation of sleep using electroencephalographic (EEG) and electromyographic (EMG) recordings in R(AB) transgenic mice that express a dominant negative form of the regulatory subunit of PKA in neurons within cortex and hippocampus. Previous studies have revealed that these mutant mice have reduced PKA activity that results in the impairment of hippocampus-dependent long-term memory and long-lasting forms of hippocampal synaptic plasticity. Design: PKA assays, in situ hybridization, immunoblots, and sleep studies were performed in R(AB) transgenic mice and wild-type control mice. Measurements and Results: We have found that R(AB) transgenic mice have reduced PKA activity within cortex and reduced Ser845 phosphorylation of the glutamate receptor subunit GluR1. R(AB) transgenic mice exhibit non-rapid eye movement (NREM) sleep fragmentation and increased amounts of rapid eye movement (REM) sleep relative to wild-type mice. Further, R(AB) transgenic mice have more delta power but less sigma power during NREM sleep relative to wild-type mice. After sleep deprivation, the amounts of NREM and REM sleep were comparable between wild-type and R(AB) transgenic mice. However, the homeostatic rebound of sigma power in R(AB) transgenic mice was reduced. Conclusions: Alterations in cortical synaptic receptors, impairments in sleep continuity, and alterations in sleep oscillations in R(AB) mice imply that PKA is involved not only in synaptic plasticity and memory storage but also in the regulation of sleep/wake states. Citation: Hellman K; Hernandez P; Park A; Abel T. Genetic evidence for a role for protein kinase a in the maintenance of sleep and thalamocortical oscillations. SLEEP 2010;33(1):19-28. PMID:20120617

Narcolepsy type 1 and hypersomnia associated with a psychiatric disorder show different slow wave activity dynamics.

PubMed

Walacik-Ufnal, Ewa; Piotrowska, Anna Justyna; Wołyńczyk-Gmaj, Dorota; Januszko, Piotr; Gmaj, Bartłomiej; Ufnal, Marcin; Kabat, Marek; Wojnar, Marcin

2017-01-01

The aim of the study was to compare electrophysiological parameters of night sleep in narcolepsy type 1 and hypersomnia associated with a psychiatric disorder. Fortyfour patients: 15 with narcolepsy type 1, 14 with hypersomnia associated with a psychiatric disorder and 15 age- and sex-matched controls participated in the study. The study subjects filled in the Athens Insomnia Scale (AIS) and the Beck Depression Inventory (BDI). The severity of daytime sleepiness was quantified subjectively using the Epworth Sleepiness Scale (ESS) and the Stanford Sleepiness Scale (SSS), and objectively using the Multiple Sleep Latency Test (MSLT). All subjects underwent polysomnography (PSG) on the two consecutive nights. The data from the second night was analysed. The slow wave activity (SWA, 1-4 Hz) was calculated for the three consecutive sleep cycles, and topographic delta power maps were plotted. In contrast to narcoleptics, psychiatric hypersomniacs had undisturbed nocturnal sleep, high sleep efficiency, normal non-rapid eye movement (NREM) and rapid eye movement (REM) sleep proportions, normal REM latency and sleep latencies on MSLT and PSG. The subjective and objective sleepiness was significantly higher in narcolepsy group than in psychiatric hypersomnia group. In all the study groups SWA was the most prominent in frontal areas, while the greatest between-group differences were found in the central areas. There were significant differences between the groups in SWA in the second NREM episode. The highest SWA was observed in the hypersomnia group, while the lowest in the narcolepsy group. Psychiatric hypersomniacs and controls did not differ in the SWA exponential decline over consecutive NREM episodes, whereas narcoleptics exhibited a steeper dissipation of sleep pressure from the first to the second NREM episode. In conclusion, narcolepsy type1 and hypersomnia associated with psychiatric disorder differ in the SWA dynamics. Narcoleptics presented with the altered dynamics of sleep homeostasis, whereas psychiatric hypersomniacs showed normal nocturnal sleep and normal sleep homeostasis.

Hornets can fly at night without obvious adaptations of eyes and ocelli.

PubMed

Kelber, Almut; Jonsson, Fredrik; Wallén, Rita; Warrant, Eric; Kornfeldt, Torill; Baird, Emily

2011-01-01

Hornets, the largest social wasps, have a reputation of being facultatively nocturnal. Here we confirm flight activity of hornet workers in dim twilight. We studied the eyes and ocelli of European hornets (Vespa crabro) and common wasps (Vespula vulgaris) with the goal to find the optical and anatomical adaptations that enable them to fly in dim light. Adaptations described for obligately nocturnal hymenoptera such as the bees Xylocopa tranquebarica and Megalopta genalis and the wasp Apoica pallens include large ocelli and compound eyes with wide rhabdoms and large facet lenses. Interestingly, we did not find any such adaptations in hornet eyes or ocelli. On the contrary, their eyes are even less sensitive than those of the obligately diurnal common wasps. Therefore we conclude that hornets, like several facultatively nocturnal bee species such as Apis mellifera adansonii, A. dorsata and X. tenuiscapa are capable of seeing in dim light simply due to the large body and thus eye size. We propose that neural pooling strategies and behavioural adaptations precede anatomical adaptations in the eyes and ocelli when insects with apposition compound eyes turn to dim light activity.

Environmental enrichment accelerates ocular dominance plasticity in mouse visual cortex whereas transfer to standard cages resulted in a rapid loss of increased plasticity.

PubMed

Kalogeraki, Evgenia; Pielecka-Fortuna, Justyna; Löwel, Siegrid

2017-01-01

In standard cage (SC) raised mice, experience-dependent ocular dominance (OD) plasticity in the primary visual cortex (V1) rapidly declines with age: in postnatal day 25-35 (critical period) mice, 4 days of monocular deprivation (MD) are sufficient to induce OD-shifts towards the open eye; thereafter, 7 days of MD are needed. Beyond postnatal day 110, even 14 days of MD failed to induce OD-plasticity in mouse V1. In contrast, mice raised in a so-called "enriched environment" (EE), exhibit lifelong OD-plasticity. EE-mice have more voluntary physical exercise (running wheels), and experience more social interactions (bigger housing groups) and more cognitive stimulation (regularly changed labyrinths or toys). Whether experience-dependent shifts of V1-activation happen faster in EE-mice and how long the plasticity promoting effect would persist after transferring EE-mice back to SCs has not yet been investigated. To this end, we used intrinsic signal optical imaging to visualize V1-activation i) before and after MD in EE-mice of different age groups (from 1-9 months), and ii) after transferring mice back to SCs after postnatal day 130. Already after 2 days of MD, and thus much faster than in SC-mice, EE-mice of all tested age groups displayed a significant OD-shift towards the open eye. Transfer of EE-mice to SCs immediately abolished OD-plasticity: already after 1 week of SC-housing and MD, OD-shifts could no longer be visualized. In an attempt to rescue abolished OD-plasticity of these mice, we either administered the anti-depressant fluoxetine (in drinking water) or supplied a running wheel in the SCs. OD-plasticity was only rescued for the running wheel- mice. Altogether our results show that raising mice in less deprived environments like large EE-cages strongly accelerates experience-dependent changes in V1-activation compared to the impoverished SC-raising. Furthermore, preventing voluntary physical exercise of EE-mice in adulthood immediately precludes OD-shifts in V1.

Environmental enrichment accelerates ocular dominance plasticity in mouse visual cortex whereas transfer to standard cages resulted in a rapid loss of increased plasticity

PubMed Central

Pielecka-Fortuna, Justyna; Löwel, Siegrid

2017-01-01

In standard cage (SC) raised mice, experience-dependent ocular dominance (OD) plasticity in the primary visual cortex (V1) rapidly declines with age: in postnatal day 25–35 (critical period) mice, 4 days of monocular deprivation (MD) are sufficient to induce OD-shifts towards the open eye; thereafter, 7 days of MD are needed. Beyond postnatal day 110, even 14 days of MD failed to induce OD-plasticity in mouse V1. In contrast, mice raised in a so-called “enriched environment” (EE), exhibit lifelong OD-plasticity. EE-mice have more voluntary physical exercise (running wheels), and experience more social interactions (bigger housing groups) and more cognitive stimulation (regularly changed labyrinths or toys). Whether experience-dependent shifts of V1-activation happen faster in EE-mice and how long the plasticity promoting effect would persist after transferring EE-mice back to SCs has not yet been investigated. To this end, we used intrinsic signal optical imaging to visualize V1-activation i) before and after MD in EE-mice of different age groups (from 1–9 months), and ii) after transferring mice back to SCs after postnatal day 130. Already after 2 days of MD, and thus much faster than in SC-mice, EE-mice of all tested age groups displayed a significant OD-shift towards the open eye. Transfer of EE-mice to SCs immediately abolished OD-plasticity: already after 1 week of SC-housing and MD, OD-shifts could no longer be visualized. In an attempt to rescue abolished OD-plasticity of these mice, we either administered the anti-depressant fluoxetine (in drinking water) or supplied a running wheel in the SCs. OD-plasticity was only rescued for the running wheel- mice. Altogether our results show that raising mice in less deprived environments like large EE-cages strongly accelerates experience-dependent changes in V1-activation compared to the impoverished SC-raising. Furthermore, preventing voluntary physical exercise of EE-mice in adulthood immediately precludes OD-shifts in V1. PMID:29073219

Role of Somatostatin-Positive Cortical Interneurons in the Generation of Sleep Slow Waves.

PubMed

Funk, Chadd M; Peelman, Kayla; Bellesi, Michele; Marshall, William; Cirelli, Chiara; Tononi, Giulio

2017-09-20

During non-rapid eye-movement (NREM) sleep, cortical and thalamic neurons oscillate every second or so between ON periods, characterized by membrane depolarization and wake-like tonic firing, and OFF periods, characterized by membrane hyperpolarization and neuronal silence. Cortical slow waves, the hallmark of NREM sleep, reflect near-synchronous OFF periods in cortical neurons. However, the mechanisms triggering such OFF periods are unclear, as there is little evidence for somatic inhibition. We studied cortical inhibitory interneurons that express somatostatin (SOM), because ∼70% of them are Martinotti cells that target diffusely layer I and can block excitatory transmission presynaptically, at glutamatergic terminals, and postsynaptically, at apical dendrites, without inhibiting the soma. In freely moving male mice, we show that SOM+ cells can fire immediately before slow waves and their optogenetic stimulation during ON periods of NREM sleep triggers long OFF periods. Next, we show that chemogenetic activation of SOM+ cells increases slow-wave activity (SWA), slope of individual slow waves, and NREM sleep duration; whereas their chemogenetic inhibition decreases SWA and slow-wave incidence without changing time spent in NREM sleep. By contrast, activation of parvalbumin+ (PV+) cells, the most numerous population of cortical inhibitory neurons, greatly decreases SWA and cortical firing, triggers short OFF periods in NREM sleep, and increases NREM sleep duration. Thus SOM+ cells, but not PV+ cells, are involved in the generation of sleep slow waves. Whether Martinotti cells are solely responsible for this effect, or are complemented by other classes of inhibitory neurons, remains to be investigated. SIGNIFICANCE STATEMENT Cortical slow waves are a defining feature of non-rapid eye-movement (NREM) sleep and are thought to be important for many of its restorative benefits. Yet, the mechanism by which cortical neurons abruptly and synchronously cease firing, the neuronal basis of the slow wave, remains unknown. Using chemogenetic and optogenetic approaches, we provide the first evidence that links a specific class of inhibitory interneurons-somatostatin-positive cells-to the generation of slow waves during NREM sleep in freely moving mice. Copyright © 2017 the authors 0270-6474/17/379132-17$15.00/0.

Botulinum toxin-induced acute anterior uveitis in a patient with Behçet's disease under infliximab treatment: a case report.

PubMed

Sasajima, Hirofumi; Yagi, Syunsuke; Osada, Hiromu; Zako, Masahiro

2017-05-04

Injections of lipopolysaccharide in animal models generate acute anterior uveitis (also known as endotoxin-induced uveitis), but the effects of lipopolysaccharide injection are unknown in humans. We describe an unusual case in which acute anterior uveitis was dramatically activated subsequent to botulinum toxin injection in a patient with Behçet's disease but the acute anterior uveitis was satisfactorily attenuated by infliximab. A 53-year-old Japanese man had normal ocular findings at his regularly scheduled appointment. He had been diagnosed as having incomplete-type Behçet's disease 11 years before. Three years after the diagnosis he was given systemic infusions of 5 mg/kg infliximab every 8 weeks and he had not experienced a uveitis attack for 8 years with no treatment other than infliximab. Two days after the eye examination, he received intracutaneous botulinum toxin injections to treat axillary hyperhidrosis on both sides. Three hours after the injections, he noted rapidly increasing floaters in his right eye. Four days after the injections, his right eye showed severe acute anterior uveitis with deteriorated aqueous flare and anterior vitreous opacity. He received his scheduled infliximab injection, and the right acute anterior uveitis immediately attenuated. Botulinum toxin may have clinical effects similar to those of lipopolysaccharide in endotoxin-induced uveitis models. To the best of our knowledge, this is the first report to suggest that botulinum toxin may trigger acute anterior uveitis, although the precise mechanism is still unclear.

Combined micro and macro additive manufacturing of a swirling flow coaxial phacoemulsifier sleeve with internal micro-vanes.

PubMed

Choi, Jae-Won; Yamashita, Masaki; Sakakibara, Jun; Kaji, Yuichi; Oshika, Tetsuro; Wicker, Ryan B

2010-10-01

Microstereolithography (microSL) technology can fabricate complex, three-dimensional (3D) microstructures, although microSL has difficulty producing macrostructures with micro-scale features. There are potentially many applications where 3D micro-features can benefit the overall function of the macrostructure. One such application involves a medical device called a coaxial phacoemulsifier where the tip of the phacoemulsifier is inserted into the eye through a relatively small incision and used to break the lens apart while removing the lens pieces and associated fluid from the eye through a small tube. In order to maintain the eye at a constant pressure, the phacoemulsifier also includes an irrigation solution that is injected into the eye during the procedure through a coaxial sleeve. It has been reported, however, that the impinging flow from the irrigation solution on the corneal endothelial cells in the inner eye can damage these cells during the procedure. As a result, a method for reducing the impinging flow velocities and the resulting shear stresses on the endothelial cells during this procedure was explored, including the design and development of a complex, 3D micro-vane within the sleeve. The micro-vane introduces swirl into the irrigation solution, producing a flow with rapidly dissipating flow velocities. Fabrication of the sleeve and fitting could not be accomplished using microSL alone, and thus, a two-part design was accomplished where a sleeve with the micro-vane was fabricated with microSL and a threaded fitting used to attach the sleeve to the phacoemulsifier was fabricated using an Objet Eden 333 rapid prototyping machine. The new combined device was tested within a water container using particle image velocimetry, and the results showed successful swirling flow with an ejection of the irrigation fluid through the micro-vane in three different radial directions corresponding to the three micro-vanes. As expected, the sleeve produced a swirling flow with rapidly dissipating streamwise flow velocities where the maximum measured streamwise flow velocities using the micro-vane were lower than those without the micro-vane by 2 mm from the tip where they remained at approximately 70% of those produced by the conventional sleeve as the flow continued to develop. It is believed that this new device will reduce damage to endothelial cells during cataract surgery and significantly improve patient outcomes from this procedure. This unique application demonstrates the utility of combining microSL with a macro rapid prototyping technology for fabricating a real macro-scale device with functional, 3D micro-scale features that would be difficult and costly to fabricate using alternative manufacturing methods.

Viewing condition dependence of the gaze-evoked nystagmus in Arnold Chiari type 1 malformation.

PubMed

Ghasia, Fatema F; Gulati, Deepak; Westbrook, Edward L; Shaikh, Aasef G

2014-04-15

Saccadic eye movements rapidly shift gaze to the target of interest. Once the eyes reach a given target, the brainstem ocular motor integrator utilizes feedback from various sources to assure steady gaze. One of such sources is cerebellum whose lesion can impair neural integration leading to gaze-evoked nystagmus. The gaze evoked nystagmus is characterized by drifts moving the eyes away from the target and a null position where the drifts are absent. The extent of impairment in the neural integration for two opposite eccentricities might determine the location of the null position. Eye in the orbit position might also determine the location of the null. We report this phenomenon in a patient with Arnold Chiari type 1 malformation who had intermittent esotropia and horizontal gaze-evoked nystagmus with a shift in the null position. During binocular viewing, the null was shifted to the right. During monocular viewing, when the eye under cover drifted nasally (secondary to the esotropia), the null of the gaze-evoked nystagmus reorganized toward the center. We speculate that the output of the neural integrator is altered from the bilateral conflicting eye in the orbit position secondary to the strabismus. This could possibly explain the reorganization of the location of the null position. Copyright © 2014 Elsevier B.V. All rights reserved.

A Compact Fiber Optic Eye Diagnostic System

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Suh, Kwang I.; Dubin, Stephen; Dellavecchia, Michael A.

1995-01-01

A new fiber optic probe developed for determining transport properties of sub-micron particles in fluid experiments in a microgravity environment has been applied to study different parts of an eye. The probe positioned in front of an eye, delivers a low power (approximately few microW) light from a laser diode into the eye and guides the light which is back scattered by different components (aqueous humor, lens, and vitreous humor) of the eye through a receiving optical fiber to a photo detector. The probe provides rapid determination of macromolecular diffusivities and their respective size distributions in the eye lens and the gel-like materials in the vitreous humor. In a clinical setting, the probe can be mounted on a standard slit-lamp apparatus simply using a Hruby lens holder. The capability of detecting cataracts, both nuclear and cortical, in their early stages of formation, in a non invasive and quantitative fashion, has the potential in patient monitoring and in developing and testing new drugs or diet therapies to 'dissolve' or slow down the cataract formation before the surgery becomes necessary. The ability to detect biochemical and macromolecular changes in the vitreous structure can be very useful in identifying certain diseases of the posterior chamber and their complications, e.g., posterior vitreous detachment and diabetic retinopathy.

A Compact Fiber Optic Eye Diagnostics System

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Suh, Kwang I.; DellaVecchia, Michael A.; Dubin, Stephen; Zigler, J. Samuel, Jr.

1995-01-01

A new fiber optic probe development for determining transport properties of sub-micron particles in fluids experiments in a microgravity environment has been applied to study different parts of the eye. The probe positioned in front of an eye, delivers a low power (approximately a few mu W) light from a laser diode into the eye and guides the light which is back scattered by different components (aqueous humor, lens, and vitreous humor) of the eye through a receiving optical fiber to a photo detector. The probe provides rapid determination of macromolecular diffusivities and their respective size distributions in the eye lens and the gel-like material in the vitreous humor. For a clinical use, the probe is mounted on a standard slit-lamp apparatus simply using Hruby lens holder. The capability of detecting cataracts, both nuclear and cortical, in their early stages of formation, in a non invasive and quantitative fashion, has the potential in patient monitoring and in developing and testing new drugs or diet therapies to 'dissolve' or slow down the cataract formation before the surgery becomes necessary. The ability to detect biochemical and macromolecular changes in the vitreous structure can be very useful in identifying certain diseases of the posterior chamber and their complications, e.g., posterior vitreous detachment and diabetic retinopathy.

Stimulus-response incompatibility activates cortex proximate to three eye fields

NASA Technical Reports Server (NTRS)

Merriam, E. P.; Colby, C. L.; Thulborn, K. R.; Luna, B.; Olson, C. R.; Sweeney, J. A.

2001-01-01

We used functional magnetic resonance imaging (fMRI) to investigate cortical activation during the performance of three oculomotor tasks that impose increasing levels of cognitive demand. (1) In a visually guided saccade (VGS) task, subjects made saccades to flashed targets. (2) In a compatible task, subjects made leftward and rightward saccades in response to foveal presentation of the uppercase words "LEFT" or "RIGHT." (3) In a mixed task, subjects made rightward saccades in response to the lowercase word "left" and leftward saccades in response to the lowercase word "right" on incompatible trials (60%). The remaining 40% of trials required compatible responses to uppercase words. The VGS and compatible tasks, when compared to fixation, activated the three cortical eye fields: the supplementary eye field (SEF), the frontal eye field (FEF), and the parietal eye field (PEF). The mixed task, when compared to the compatible task, activated three additional cortical regions proximate to the three eye fields: (1) rostral to the SEF in medial frontal cortex; (2) rostral to the FEF in dorsolateral prefrontal cortex (DLPFC); (3) rostral and lateral to the PEF in posterior parietal cortex. These areas may contribute to the suppression of prepotent responses and in holding novel visuomotor associations in working memory. Copyright 2001 Academic Press.

Ras promotes cell survival by antagonizing both JNK and Hid signals in the Drosophila eye.

PubMed

Wu, Yue; Zhuang, Yuan; Han, Min; Xu, Tian; Deng, Kejing

2009-10-20

Programmed cell death, or apoptosis, is a fundamental physiological process during normal development or in pathological conditions. The activation of apoptosis can be elicited by numerous signalling pathways. Ras is known to mediate anti-apoptotic signals by inhibiting Hid activity in the Drosophila eye. Here we report the isolation of a new loss-of-function ras allele, rasKP, which causes excessive apoptosis in the Drosophila eye. This new function is likely to be mediated through the JNK pathway since the inhibition of JNK signalling can significantly suppress rasKP-induced apoptosis, whereas the removal of hid only weakly suppresses the phenotype. Furthermore, the reduction of JNK signalling together with the expression of the baculovirus caspase inhibitor p35, which blocks Hid activity, strongly suppresses the rasKP cell death. In addition, we find a strong correlation between rasKP-induced apoptosis in the eye disc and the activation of JNK signalling. In the Drosophila eye, Ras may protect cells from apoptosis by inhibiting both JNK and Hid activities. Surprisingly, reducing Ras activity in the wing, however, does not cause apoptosis but rather affects cell and organ size. Thus, in addition to its requirement for cell viability, Ras appears to mediate different biological roles depending on the developmental context and on the level of its expression.

A Fiber Optic Probe for the Detection of Cataracts

NASA Technical Reports Server (NTRS)

Ansari, Rafat R.; Dhadwal, Harbans S.

1993-01-01

A compact fiber optic probe developed for on-orbit science experiments was used to detect the onset of cataracts, a capability that could eliminate physicians' guesswork and result in new drugs to 'dissolve' or slow down the cataract formation before surgery is necessary. The probe is based upon dynamic light scattering (DLS) principles. It has no moving parts, no apertures, and requires no optical alignment. It is flexible and easy to use. Results are presented for excised but intact human eye lenses. In a clinical setting, the device can be easily incorporated into a slit-lamp apparatus (ophthalmoscope) for complete eye diagnostics. In this set-up, the integrated fiber optic probe, the size of a pencil, delivers a low power cone of laser light into the eye of a patient and guides the light which is backscattered by the protein molecules of the lens through a receiving optical fiber to a photo detector. The non-invasive DLS measurements provide rapid determination of protein crystalline size and its size distribution in the eye lens.

[Ocular graft-versus-host disease: An often misdiagnosed etiology of dry eye syndrome].

PubMed

Moyal, L; Adam, R; Akesbi, J; Rodallec, F T; Nordmann, J-P

2017-02-01

To report a case of severe ocular graft-versus-host disease (GVHD) after cataract surgery. Observational case report. We describe the case of a 59-year-old man with postoperative corneal ulcer on his only functional eye. His past history reported allogenic bone marrow transplant. His visual acuity (VA) was limited to hand motions. Slit lamp examination revealed diffuse conjunctival hyperemia, severe blepharitis, Meibomian dysfunction, total corneal opacification with epithelial and stromal keratitis and neovascular invasion. Because of the severe dry eye symptoms and history of allogenic hematological stem cell transplantation, ocular GVHD was diagnosed. Functional and anatomical improvement occurred rapidly with topical cyclosporine 2%, with improved VA after treatment. With any severe dry eye syndrome in the context of allogenic bone marrow transplant, ocular GVHD must be considered. For planned ocular surgery, we recommend adding cyclosporine 0.1% treatment before and after surgery to prevent severe ocular GVHD. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Eye Carduino: A Car Control System using Eye Movements

NASA Astrophysics Data System (ADS)

Kumar, Arjun; Nagaraj, Disha; Louzardo, Joel; Hegde, Rajeshwari

2011-12-01

Modern automotive systems are rapidly becoming highly of transportation, but can be a web integrated media centre. This paper explains the implementation of a vehicle control defined and characterized by embedded electronics and software. With new technologies, the vehicle industry is facing new opportunities and also new challenges. Electronics have improved the performance of vehicles and at the same time, new more complex applications are introduced. Examples of high level applications include adaptive cruise control and electronic stability programs (ESP). Further, a modern vehicle does not have to be merely a means using only eye movements. The EyeWriter's native hardware and software work to return the co-ordinates of where the user is looking. These co-ordinates are then used to control the car. A centre-point is defined on the screen. The higher on the screen the user's gaze is, the faster the car will accelerate. Braking is done by looking below centre. Steering is done by looking left and right on the screen.

The real-time prediction and inhibition of linguistic outcomes: Effects of language and literacy skill.

PubMed

Kukona, Anuenue; Braze, David; Johns, Clinton L; Mencl, W Einar; Van Dyke, Julie A; Magnuson, James S; Pugh, Kenneth R; Shankweiler, Donald P; Tabor, Whitney

2016-11-01

Recent studies have found considerable individual variation in language comprehenders' predictive behaviors, as revealed by their anticipatory eye movements during language comprehension. The current study investigated the relationship between these predictive behaviors and the language and literacy skills of a diverse, community-based sample of young adults. We found that rapid automatized naming (RAN) was a key determinant of comprehenders' prediction ability (e.g., as reflected in predictive eye movements to a white cake on hearing "The boy will eat the white…"). Simultaneously, comprehension-based measures predicted participants' ability to inhibit eye movements to objects that shared features with predictable referents but were implausible completions (e.g., as reflected in eye movements to a white but inedible white car). These findings suggest that the excitatory and inhibitory mechanisms that support prediction during language processing are closely linked with specific cognitive abilities that support literacy. We show that a self-organizing cognitive architecture captures this pattern of results. Copyright © 2016 Elsevier B.V. All rights reserved.

Orexin and Epilepsy: Potential Role of REM Sleep.

PubMed

Ng, Marcus C

2017-03-01

Interest in orexin receptor antagonism as a novel mechanism of action against seizures and epilepsy has increased in recent years. Loss of orexinergic activity is associated with rapid eye movement (REM) sleep onset, and REM sleep is generally protective against seizures. This paper discusses the dynamic modulation of seizure threshold by orexin through a postulated "orexi-cortical" axis in which the specific type of orexinergic activity exquisitely regulates sleep-wake states to modify ascending subcortical influences on cortical synchronization with profound subsequent consequences on seizure threshold. This paper also explores the current state of research into experimental orexinergic modulation of seizure threshold and suggests possible future research directions to fully understand the promise and peril of orexinergic manipulation in seizures and epilepsy. © Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Neuronal plasticity and thalamocortical sleep and waking oscillations

PubMed Central

Timofeev, Igor

2011-01-01

Throughout life, thalamocortical (TC) network alternates between activated states (wake or rapid eye movement sleep) and slow oscillatory state dominating slow-wave sleep. The patterns of neuronal firing are different during these distinct states. I propose that due to relatively regular firing, the activated states preset some steady state synaptic plasticity and that the silent periods of slow-wave sleep contribute to a release from this steady state synaptic plasticity. In this respect, I discuss how states of vigilance affect short-, mid-, and long-term synaptic plasticity, intrinsic neuronal plasticity, as well as homeostatic plasticity. Finally, I suggest that slow oscillation is intrinsic property of cortical network and brain homeostatic mechanisms are tuned to use all forms of plasticity to bring cortical network to the state of slow oscillation. However, prolonged and profound shift from this homeostatic balance could lead to development of paroxysmal hyperexcitability and seizures as in the case of brain trauma. PMID:21854960

A Hypothalamic Switch for REM and Non-REM Sleep.

PubMed

Chen, Kai-Siang; Xu, Min; Zhang, Zhe; Chang, Wei-Cheng; Gaj, Thomas; Schaffer, David V; Dan, Yang

2018-03-07

Rapid eye movement (REM) and non-REM (NREM) sleep are controlled by specific neuronal circuits. Here we show that galanin-expressing GABAergic neurons in the dorsomedial hypothalamus (DMH) comprise separate subpopulations with opposing effects on REM versus NREM sleep. Microendoscopic calcium imaging revealed diverse sleep-wake activity of DMH GABAergic neurons, but the galanin-expressing subset falls into two distinct groups, either selectively activated (REM-on) or suppressed (REM-off) during REM sleep. Retrogradely labeled, preoptic area (POA)-projecting galaninergic neurons are REM-off, whereas the raphe pallidus (RPA)-projecting neurons are primarily REM-on. Bidirectional optogenetic manipulations showed that the POA-projecting neurons promote NREM sleep and suppress REM sleep, while the RPA-projecting neurons have the opposite effects. Thus, REM/NREM switch is regulated antagonistically by DMH galaninergic neurons with intermingled cell bodies but distinct axon projections. Copyright © 2018 Elsevier Inc. All rights reserved.

Sedative Effect of Sophora flavescens and Matrine

PubMed Central

Lee, Hyun-ju; Lee, Sun-young; Jang, Daehyuk; Chung, Sun-Yong; Shim, Insop

2017-01-01

The present study investigated the sedative effects of Sophora flavescens (SF) and its bioactive compound, matrine through performing locomotor activity test and the electroencephalography (EEG) analysis in the rat. The underlying neural mechanism of their beneficial effects was determined by assessing c-Fos immunoreactivity and serotonin (5-HT) in the brain utilizing immunohistochemical method and enzyme-linked immunosorbent assay. The results showed that SF and matrine administration had an effect on normalization of caffeine-induced hyperactivity and promoting a shift toward non-rapid eye movement (NREM) sleep. c-Fos-immunoreactivity and 5-HT level in the ventrolateral preoptic nucleus (VLPO), a sleep promoting region, were increased in the both SF and matrine-injected groups. In conclusion, SF and its bioactive compound, matrine alleviated caffeine-induced hyperactivity and promoted NREM sleep by activating VLPO neurons and modulating serotonergic transmission. It is suggested that SF might be a useful natural alternatives for hypnotic medicine. PMID:28190318

Sedative Effect of Sophora flavescens and Matrine.

PubMed

Lee, Hyun-Ju; Lee, Sun-Young; Jang, Daehyuk; Chung, Sun-Yong; Shim, Insop

2017-07-01

The present study investigated the sedative effects of Sophora flavescens (SF) and its bioactive compound, matrine through performing locomotor activity test and the electroencephalography (EEG) analysis in the rat. The underlying neural mechanism of their beneficial effects was determined by assessing c-Fos immunoreactivity and serotonin (5-HT) in the brain utilizing immunohistochemical method and enzyme-linked immunosorbent assay. The results showed that SF and matrine administration had an effect on normalization of caffeine-induced hyperactivity and promoting a shift toward non-rapid eye movement (NREM) sleep. c-Fos-immunoreactivity and 5-HT level in the ventrolateral preoptic nucleus (VLPO), a sleep promoting region, were increased in the both SF and matrine-injected groups. In conclusion, SF and its bioactive compound, matrine alleviated caffeine-induced hyperactivity and promoted NREM sleep by activating VLPO neurons and modulating serotonergic transmission. It is suggested that SF might be a useful natural alternatives for hypnotic medicine.

Real-time lexical comprehension in young children learning American Sign Language.

PubMed

MacDonald, Kyle; LaMarr, Todd; Corina, David; Marchman, Virginia A; Fernald, Anne

2018-04-16

When children interpret spoken language in real time, linguistic information drives rapid shifts in visual attention to objects in the visual world. This language-vision interaction can provide insights into children's developing efficiency in language comprehension. But how does language influence visual attention when the linguistic signal and the visual world are both processed via the visual channel? Here, we measured eye movements during real-time comprehension of a visual-manual language, American Sign Language (ASL), by 29 native ASL-learning children (16-53 mos, 16 deaf, 13 hearing) and 16 fluent deaf adult signers. All signers showed evidence of rapid, incremental language comprehension, tending to initiate an eye movement before sign offset. Deaf and hearing ASL-learners showed similar gaze patterns, suggesting that the in-the-moment dynamics of eye movements during ASL processing are shaped by the constraints of processing a visual language in real time and not by differential access to auditory information in day-to-day life. Finally, variation in children's ASL processing was positively correlated with age and vocabulary size. Thus, despite competition for attention within a single modality, the timing and accuracy of visual fixations during ASL comprehension reflect information processing skills that are important for language acquisition regardless of language modality. © 2018 John Wiley & Sons Ltd.

Creutzfeldt-Jakob Disease Presenting With Dizziness and Gaze-Evoked Nystagmus: A Case Report.

PubMed

Choi, Yun-Ju; Kang, Kyung-Wook; Lee, Sae-Young; Kang, Seung-Ho; Lee, Seung-Han; Kim, Byeong C

2016-02-01

Sporadic Creutzfeldt-Jakob disease (CJD) is clinically characterized by rapidly progressive dementia combined with other cardinal symptoms, such as myoclonus, visual or cerebellar disturbances, extrapyramidal or pyramidal disturbance, and akinetic mutism. However, as an initial manifestation, focal neurologic deficits other than the aforementioned or nonspecific generalized symptoms may lead to a misdiagnosis or a delayed diagnosis. The authors report a case of 66-year-old male patient with sporadic CJD who had dizziness, gaze-evoked nystagmus (GEN), and other central eye signs (impaired smooth pursuit, saccadic dysmetria) as an initial manifestation without dementia. The central eye signs led us to perform brain magnetic resonance images, which showed abnormal cortical high-signal intensity in both the cerebral and cerebellar hemispheres including the vestibulocerebellum. We reached a presumptive diagnosis of CJD, but the findings did not meet diagnostic criteria for probable CJD at that time. Three weeks after the initial work-ups, the patient presented with typical neurological findings of CJD: rapidly progressive dementia, akinetic mutism, and myoclonus of the left arm. Cerebrospinal fluid was positive for 14-3-3 protein, and electroencephalography showed periodic sharp wave complexes. In this patient, GEN and other central eye signs provided diagnostic clues for CJD. These unusual neurological manifestations may help physicians have a thorough knowledge of early deficits of CJD.

The Rapid Intensification of Hurricane Karl (2010): New Remote Sensing Observations of Convective Bursts from the Global Hawk Platform

NASA Technical Reports Server (NTRS)

Guimond, Stephen R.; Heymsfield, Gerald M.; Reasor, Paul; Didlake, Anthony C., Jr.

2016-01-01

The evolution of rapidly intensifying Hurricane Karl (2010) is examined from a suite of remote sensing observations during the NASA Genesis and Rapid Intensification Processes (GRIP) field experiment. The novelties of this study are in the analysis of data from the airborne Doppler radar HIWRAP and the new Global Hawk airborne platform that allows long endurance sampling of hurricanes. Supporting data from the HAMSR microwave sounder coincident with HIWRAP and coordinated flights with the NOAA WP-3D aircraft help to provide a comprehensive understanding of the storm. The focus of the analysis is on documenting and understanding the structure, evolution and role of small scale, deep convective forcing in the storm intensification process. Deep convective bursts are sporadically initiated in the downshear quadrants of the storm and rotate into the upshear quadrants for a period of 12 h during the rapid intensification. The aircraft data analysis indicates that the bursts are being formed and maintained through a combination of two main processes: (1) convergence generated from counter-rotating mesovortex circulations and the larger vortex-scale flow and (2) the turbulent (scales of 25 km) transport of anomalously warm, buoyant air from the eye to the eyewall at low levels. The turbulent mixing across the eyewall interface and forced convective descent adjacent to the bursts assists in carving out the eye of Karl, which leads to an asymmetric enhancement of the warm core. The mesovortices play a key role in the evolution of the features described above.The Global Hawk aircraft allowed an examination of the vortex response and axisymmetrization period in addition to the burst pulsing phase. A pronounced axisymmetric development of the vortex is observed following the pulsing phase that includes a sloped eyewall structure and formation of a clear, wide eye.