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Sample records for awake freely behaving

  1. Age-Related Decrease in the Schaffer Collateral-Evoked EPSP in Awake, Freely, Behaving Rats

    PubMed Central

    Barnes, C. A.; Rao, G.; Orr, G.

    2000-01-01

    Synaptic response size in the CA1 region of the hippocampus in aged rats is reduced for a given stimulus intensity, compared with that elicited in young rats. Consistent with the in vitro findings of reduced Schaffer collateral-evoked CA1 EPSPs in old rats, the population currents evoked to iontophoretically applied AMPA are also smaller relative to the presynaptic fiber potential amplitude. On the other hand, the size of the presynaptic fiber potential and amplitude of unitary intra-cellularly recorded EPSP responses do not change across age in the CA1 region. These electrophysiological findings are consistent with the hypothesis that old rats have fewer functional synaptic contacts per Schaffer collateral axon than do young rats. The possibility that this age change arises as a result of a differential tissue recovery response to in vitro preparation was examined in the present study. CA1 presynaptic fiber potential and EPSP amplitudes evoked by the stimulation of Schaffer collateral afferents were studied in intact, freely behaving young and old rats. We confirmed in vivo the pattern of electrophysiophysiological results previously reported in vitro and found significant correlations between the synaptic response amplitudes and the accuracy of spatial behavior in the Morris swim task. The data suggest that changes in functional connectivity of old rats may be a significant contributor to cognitive changes during aging. PMID:11147459

  2. Stimulation of Perforant Path Fibers Induces LTP Concurrently in Amygdala and Hippocampus in Awake Freely Behaving Rats

    PubMed Central

    Blaise, J. Harry; Hartman, Rachel A.

    2013-01-01

    Long-term potentiation (LTP) which has long been considered a cellular model for learning and memory is defined as a lasting enhancement in synaptic transmission efficacy. This cellular mechanism has been demonstrated reliably in the hippocampus and the amygdala—two limbic structures implicated in learning and memory. Earlier studies reported on the ability of cortical stimulation of the entorhinal cortex to induce LTP simultaneously in the two sites. However, to retain a stable baseline of comparison with the majority of the LTP literature, it is important to investigate the ability of fiber stimulation such as perforant path activation to induce LTP concurrently in both structures. Therefore, in this paper we report on concurrent LTP in the basolateral amygdala (BLA) and the dentate gyrus (DG) subfield of the hippocampus induced by theta burst stimulation of perforant path fibers in freely behaving Sprague-Dawley rats. Our results indicate that while perforant path-evoked potentials in both sites exhibit similar triphasic waveforms, the latency and amplitude of BLA responses were significantly shorter and smaller than those of DG. In addition, we observed no significant differences in either the peak level or the duration of LTP between DG and BLA. PMID:23401801

  3. Wireless neural stimulation in freely behaving small animals.

    PubMed

    Arfin, Scott K; Long, Michael A; Fee, Michale S; Sarpeshkar, Rahul

    2009-07-01

    We introduce a novel wireless, low-power neural stimulation system for use in freely behaving animals. The system consists of an external transmitter and a miniature, implantable wireless receiver-stimulator. The implant uses a custom integrated chip to deliver biphasic current pulses to four addressable bipolar electrodes at 32 selectable current levels (10 microA to 1 mA). To achieve maximal battery life, the chip enters a sleep mode when not needed and can be awakened remotely when required. To test our device, we implanted bipolar stimulating electrodes into the songbird motor nucleus HVC (formerly called the high vocal center) of zebra finches. Single-neuron recordings revealed that wireless stimulation of HVC led to a strong increase of spiking activity in its downstream target, the robust nucleus of the arcopallium. When we used this device to deliver biphasic pulses of current randomly during singing, singing activity was prematurely terminated in all birds tested. Thus our device is highly effective for remotely modulating a neural circuit and its corresponding behavior in an untethered, freely behaving animal. PMID:19386759

  4. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans

    PubMed Central

    Nguyen, Jeffrey P.; Shipley, Frederick B.; Linder, Ashley N.; Plummer, George S.; Liu, Mochi; Setru, Sagar U.; Shaevitz, Joshua W.

    2016-01-01

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. We present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal’s position, posture, and locomotion. This instrument provides whole-brain imaging with cellular resolution in an unrestrained and behaving animal. We use spinning-disk confocal microscopy to capture 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s at 6 head-volumes/s. A suite of three cameras monitor neuronal fluorescence and the animal’s position and orientation. Custom software tracks the 3D position of the animal’s head in real time and two feedback loops adjust a motorized stage and objective to keep the animal’s head within the field of view as the animal roams freely. We observe calcium transients from up to 77 neurons for over 4 min and correlate this activity with the animal’s behavior. We characterize noise in the system due to animal motion and show that, across worms, multiple neurons show significant correlations with modes of behavior corresponding to forward, backward, and turning locomotion. PMID:26712014

  5. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans.

    PubMed

    Nguyen, Jeffrey P; Shipley, Frederick B; Linder, Ashley N; Plummer, George S; Liu, Mochi; Setru, Sagar U; Shaevitz, Joshua W; Leifer, Andrew M

    2016-02-23

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. We present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. This instrument provides whole-brain imaging with cellular resolution in an unrestrained and behaving animal. We use spinning-disk confocal microscopy to capture 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s at 6 head-volumes/s. A suite of three cameras monitor neuronal fluorescence and the animal's position and orientation. Custom software tracks the 3D position of the animal's head in real time and two feedback loops adjust a motorized stage and objective to keep the animal's head within the field of view as the animal roams freely. We observe calcium transients from up to 77 neurons for over 4 min and correlate this activity with the animal's behavior. We characterize noise in the system due to animal motion and show that, across worms, multiple neurons show significant correlations with modes of behavior corresponding to forward, backward, and turning locomotion. PMID:26712014

  6. Studying the freely-behaving brain with fMRI.

    PubMed

    Maguire, Eleanor A

    2012-08-15

    Given that the brain evolved to function in the real world then it seems reasonable to want to examine how it operates in that context. But of course the world is complex, as are the brain's responses to it, and MRI scanners are inherently restrictive environments. This combination of challenges makes the prospect of studying the freely-behaving brain with fMRI disconcerting to anyone sensible. When designing naturalistic fMRI experiments it is necessary to ensure that the thoughts or behaviours under scrutiny are not unduly perturbed or constrained by the imaging process, while still being amenable to experimental manipulation and control, and result in meaningful and interpretable data. This is difficult to achieve. Here, briefly, and in a highly subjective and selective manner, I consider: why we might want to deploy free-behaviour designs in an fMRI context, how to go about it, review some examples of it in action, and decide finally whether it is worth it (it is).

  7. Neuronal correlates of siphon withdrawal in freely behaving Aplysia.

    PubMed

    Kanz, J E; Eberly, L B; Cobbs, J S; Pinsker, H M

    1979-11-01

    1. Central neuronal mechanisms of siphon withdrawal in Aplysia were studied for the first time in intact, freely behaving animals by means of population recordings from implanted whole-nerve cuff electrodes. Intracellular follow-up studies were then conducted when the same animal was reduced to a semi-intact preparation. 2. Background spontaneous activity in the siphon nerve consisted of low-frequency firing of a population of efferent units containing identified siphon motoneurons. 3. Spontaneous patterned bursts of efferent activity occurred irregularly and were associated with all-or-nothing contractions of the parapodia, gill, and siphon. Spontaneous bursts were due to centrally generated activity in the interneuron II (INT II) network, an oscillatory network with endogenous pacemaker properties. 4. In intact animals, even weak tactile stimuli to the siphon typically triggered an INTII burst shortly after the stimulus-locked efferent activity. Thus, the stimulus can phase-advance the INT II oscillator. In semi-intact preparations, short-latency INT II bursts were triggered less less frequently and required more intense stimuli. 5. With weak to moderate-intensity stimuli in intact animals, the presence of short-latency triggered INT II bursts largely determined the duration of the siphon component and amplitude of the gill component of the withdrawal reflex. 6. When stimuli were repeated over a range of interstimulus intervals (from 60 to 1 min), the likelihood of triggering a short-latency INT II burst die not change systematically. Thus, the ability of the siphon stimulus to stably entrain the all-or-none INT II component over a wide range of intervals will interact behaviorally with the decrement of the monosynaptic component of the reflex with repetition.

  8. Imaging the Dynamics of Neocortical Population Activity in Behaving and Freely Moving Mammals.

    PubMed

    Grinvald, Amiram; Petersen, Carl C H

    2015-01-01

    The development of functional imaging techniques applicable to neuroscience and covering a wide range of spatial and temporal scales has greatly facilitated the exploration of the relationships between cognition, behaviour and electrical brain activity. For mammals, the neocortex plays a particularly profound role in generating sensory perception, controlling voluntary movement, higher cognitive functions and planning goal-directed behaviours. Since these remarkable functions of the neocortex cannot be explored in simple model preparations or in anesthetised animals, the neural basis of behaviour must be explored in awake behaving subjects. Because neocortical function is highly distributed across many rapidly interacting regions, it is essential to measure spatiotemporal dynamics of cortical activity in real-time. Extensive work in anesthetised mammals has shown that in vivo Voltage-Sensitive Dye Imaging (VSDI) reveals the neocortical population membrane potential dynamics at millisecond temporal resolution and subcolumnar spatial resolution. Here, we describe recent advances indicating that VSDI is also already well-developed for exploring cortical function in behaving monkeys and mice. The first animal model, the non-human primate, is well-suited for fundamental exploration of higher-level cognitive function and behavior. The second animal model, the mouse, benefits from a rich arsenal of molecular and genetic technologies. In the monkey, imaging from the same patch of cortex, repeatedly, is feasible for a long period of time, up to a year. In the rodent, VSDI is applicable to freely moving and awake head-restrained mice. Interactions between different cortical areas and different cortical columns can therefore now be dynamically mapped through VSDI and related to the corresponding behaviour. Thus by applying VSDI to mice and monkeys one can begin to explore how behaviour emerges from neuronal activity in neuronal networks residing in different cortical areas

  9. Chronic monitoring of cortical hemodynamics in behaving, freely-moving rats using a miniaturized head-mounted optical microscope

    NASA Astrophysics Data System (ADS)

    Sigal, Iliya; Gad, Raanan; Koletar, Margaret; Ringuette, Dene; Stefanovic, Bojana; Levi, Ofer

    2016-03-01

    Growing interest within the neurophysiology community in assessing healthy and pathological brain activity in animals that are awake and freely-behaving has triggered the need for optical systems that are suitable for such longitudinal studies. In this work we report label-free multi-modal imaging of cortical hemodynamics in the somatosensory cortex of awake, freely-behaving rats, using a novel head-mounted miniature optical microscope. The microscope employs vertical cavity surface emitting lasers (VCSELs) at three distinct wavelengths (680 nm, 795 nm, and 850 nm) to provide measurements of four hemodynamic markers: blood flow speeds, HbO, HbR, and total Hb concentration, across a > 2 mm field of view. Blood flow speeds are extracted using Laser Speckle Contrast Imaging (LSCI), while oxygenation measurements are performed using Intrinsic Optical Signal Imaging (IOSI). Longitudinal measurements on the same animal are made possible over the course of > 6 weeks using a chronic window that is surgically implanted into the skull. We use the device to examine changes in blood flow and blood oxygenation in superficial cortical blood vessels and tissue in response to drug-induced absence-like seizures, correlating motor behavior with changes in blood flow and blood oxygenation in the brain.

  10. Whole-brain calcium imaging with cellular resolution in freely behaving Caenorhabditis elegans

    NASA Astrophysics Data System (ADS)

    Nguyen, Jeffrey; Shipley, Frederick; Linder, Ashley; Plummer, George; Liu, Mochi; Setru, Sagar; Shaevitz, Joshua; Leifer, Andrew

    The ability to acquire large-scale recordings of neuronal activity in awake and unrestrained animals is needed to provide new insights into how populations of neurons generate animal behavior. Acquiring this data, however, is challenging because it is difficult to track and image individual neurons as an animal deforms its posture and moves many body lengths. Here, we present an instrument capable of recording intracellular calcium transients from the majority of neurons in the head of a freely behaving Caenorhabditis elegans with cellular resolution while simultaneously recording the animal's position, posture, and locomotion. 3D volumetric fluorescent images of neurons expressing the calcium indicator GCaMP6s are recorded at 6 head-volumes/s using spinning disk confocal microscopy. At the same time, we record low magnification images of the animal to measure the animals behavior and track its head as it moves. We develop a time independent neuronal matching algorithm that uses non-rigid point set registration and machine learning to correctly match neurons across time. Using this method, we are able to observe calcium transients from up to 90 neurons for over 4 min and correlate the neural activity with the animal's behavior.

  11. Photoacoustic detection of functional responses in the motor cortex of awake behaving monkey during forelimb movement

    NASA Astrophysics Data System (ADS)

    Jo, Janggun; Zhang, Hongyu; Cheney, Paul D.; Yang, Xinmai

    2012-11-01

    Photoacoustic (PA) imaging was applied to detect the neuronal activity in the motor cortex of an awake, behaving monkey during forelimb movement. An adult macaque monkey was trained to perform a reach-to-grasp task while PA images were acquired through a 30-mm diameter implanted cranial chamber. Increased PA signal amplitude results from an increase in regional blood volume and is interpreted as increased neuronal activity. Additionally, depth-resolved PA signals enabled the study of functional responses in deep cortical areas. The results demonstrate the feasibility of utilizing PA imaging for studies of functional activation of cerebral cortex in awake monkeys performing behavioral tasks.

  12. Sampling phasic dopamine signaling with fast-scan cyclic voltammetry in awake behaving rats

    PubMed Central

    Fortin, SM; Cone, JJ; Ng-Evans, S; McCutcheon, JE; Roitman, MF

    2015-01-01

    Fast-scan cyclic voltammetry (FSCV) is an electrochemical technique which permits the in vivo measurement of extracellular fluctuations in multiple chemical species. The technique is frequently utilized to sample sub-second (phasic) concentration changes of the neurotransmitter dopamine in awake and behaving rats. Phasic dopamine signaling is implicated in reinforcement, goal-directed behavior, and locomotion and FSCV has been used to investigate how rapid changes in striatal dopamine concentration contribute to these and other behaviors. This unit describes the instrumentation and construction, implantation, and use of necessary components required to sample and analyze dopamine concentration changes in awake rats with FSCV. PMID:25559005

  13. Evolving Models of Pavlovian Conditioning: Cerebellar Cortical Dynamics in Awake Behaving Mice

    PubMed Central

    ten Brinke, Michiel M.; Boele, Henk-Jan; Spanke, Jochen K.; Potters, Jan-Willem; Kornysheva, Katja; Wulff, Peer; IJpelaar, Anna C.H.G.; Koekkoek, Sebastiaan K.E.; De Zeeuw, Chris I.

    2015-01-01

    Summary Three decades of electrophysiological research on cerebellar cortical activity underlying Pavlovian conditioning have expanded our understanding of motor learning in the brain. Purkinje cell simple spike suppression is considered to be crucial in the expression of conditional blink responses (CRs). However, trial-by-trial quantification of this link in awake behaving animals is lacking, and current hypotheses regarding the underlying plasticity mechanisms have diverged from the classical parallel fiber one to the Purkinje cell synapse LTD hypothesis. Here, we establish that acquired simple spike suppression, acquired conditioned stimulus (CS)-related complex spike responses, and molecular layer interneuron (MLI) activity predict the expression of CRs on a trial-by-trial basis using awake behaving mice. Additionally, we show that two independent transgenic mouse mutants with impaired MLI function exhibit motor learning deficits. Our findings suggest multiple cerebellar cortical plasticity mechanisms underlying simple spike suppression, and they implicate the broader involvement of the olivocerebellar module within the interstimulus interval. PMID:26655909

  14. Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system

    PubMed Central

    Sigal, Iliya; Koletar, Margaret M.; Ringuette, Dene; Gad, Raanan; Jeffrey, Melanie; Carlen, Peter L.; Stefanovic, Bojana; Levi, Ofer

    2016-01-01

    We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 − 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy. PMID:27699123

  15. Imaging brain activity during seizures in freely behaving rats using a miniature multi-modal imaging system

    PubMed Central

    Sigal, Iliya; Koletar, Margaret M.; Ringuette, Dene; Gad, Raanan; Jeffrey, Melanie; Carlen, Peter L.; Stefanovic, Bojana; Levi, Ofer

    2016-01-01

    We report on a miniature label-free imaging system for monitoring brain blood flow and blood oxygenation changes in awake, freely behaving rats. The device, weighing 15 grams, enables imaging in a ∼ 2 × 2 mm field of view with 4.4 μm lateral resolution and 1 − 8 Hz temporal sampling rate. The imaging is performed through a chronically-implanted cranial window that remains optically clear between 2 to > 6 weeks after the craniotomy. This imaging method is well suited for longitudinal studies of chronic models of brain diseases and disorders. In this work, it is applied to monitoring neurovascular coupling during drug-induced absence-like seizures 6 weeks following the craniotomy.

  16. Miniature microscopes for large-scale imaging of neuronal activity in freely behaving rodents.

    PubMed

    Ziv, Yaniv; Ghosh, Kunal K

    2015-06-01

    Recording neuronal activity in behaving subjects has been instrumental in studying how information is represented and processed by the brain. Recent advances in optical imaging and bioengineering have converged to enable time-lapse, cell-type specific recordings of neuronal activities from large neuronal populations in deep-brain structures of freely behaving rodents. We will highlight these advancements, with an emphasis on miniaturized integrated microscopy for large-scale imaging in freely behaving mice. This technology potentially enables studies that were difficult to perform using previous generation imaging and current electrophysiological techniques. These studies include longitudinal and population-level analyses of neuronal representations associated with different types of naturalistic behaviors and cognitive or emotional processes. PMID:25951292

  17. Miniature microscopes for large-scale imaging of neuronal activity in freely behaving rodents.

    PubMed

    Ziv, Yaniv; Ghosh, Kunal K

    2015-06-01

    Recording neuronal activity in behaving subjects has been instrumental in studying how information is represented and processed by the brain. Recent advances in optical imaging and bioengineering have converged to enable time-lapse, cell-type specific recordings of neuronal activities from large neuronal populations in deep-brain structures of freely behaving rodents. We will highlight these advancements, with an emphasis on miniaturized integrated microscopy for large-scale imaging in freely behaving mice. This technology potentially enables studies that were difficult to perform using previous generation imaging and current electrophysiological techniques. These studies include longitudinal and population-level analyses of neuronal representations associated with different types of naturalistic behaviors and cognitive or emotional processes.

  18. Functional recordings from awake, behaving rodents through a microchannel based regenerative neural interface

    PubMed Central

    Gore, Russell K.; Choi, Yoonsu; Bellamkonda, Ravi; English, Arthur

    2015-01-01

    Objective Neural interface technologies could provide controlling connections between the nervous system and external technologies, such as limb prosthetics. The recording of efferent, motor potentials is a critical requirement for a peripheral neural interface, as these signals represent the user-generated neural output intended to drive external devices. Our objective was to evaluate structural and functional neural regeneration through a microchannel neural interface and to characterize potentials recorded from electrodes placed within the microchannels in awake and behaving animals. Approach Female rats were implanted with muscle EMG electrodes and, following unilateral sciatic nerve transection, the cut nerve was repaired either across a microchannel neural interface or with end-to-end surgical repair. During a 13-week recovery period, direct muscle responses to nerve stimulation proximal to the transection were monitored weekly. In two rats repaired with the neural interface, four wire electrodes were embedded in the microchannels and recordings were obtained within microchannels during proximal stimulation experiments and treadmill locomotion. Main results In these proof-of-principle experiments, we found that axons from cut nerves were capable of functional reinnervation of distal muscle targets, whether regenerating through a microchannel device or after direct end-to-end repair. Discrete stimulation-evoked and volitional potentials were recorded within interface microchannels in a small group of awake and behaving animals and their firing patterns correlated directly with intramuscular recordings during locomotion. Of 38 potentials extracted, 19 were identified as motor axons reinnervating tibialis anterior or soleus muscles using spike triggered averaging. Significance These results are evidence for motor axon regeneration through microchannels and are the first report of in vivo recordings from regenerated motor axons within microchannels in a small

  19. Functional recordings from awake, behaving rodents through a microchannel based regenerative neural interface

    NASA Astrophysics Data System (ADS)

    Gore, Russell K.; Choi, Yoonsu; Bellamkonda, Ravi; English, Arthur

    2015-02-01

    Objective. Neural interface technologies could provide controlling connections between the nervous system and external technologies, such as limb prosthetics. The recording of efferent, motor potentials is a critical requirement for a peripheral neural interface, as these signals represent the user-generated neural output intended to drive external devices. Our objective was to evaluate structural and functional neural regeneration through a microchannel neural interface and to characterize potentials recorded from electrodes placed within the microchannels in awake and behaving animals. Approach. Female rats were implanted with muscle EMG electrodes and, following unilateral sciatic nerve transection, the cut nerve was repaired either across a microchannel neural interface or with end-to-end surgical repair. During a 13 week recovery period, direct muscle responses to nerve stimulation proximal to the transection were monitored weekly. In two rats repaired with the neural interface, four wire electrodes were embedded in the microchannels and recordings were obtained within microchannels during proximal stimulation experiments and treadmill locomotion. Main results. In these proof-of-principle experiments, we found that axons from cut nerves were capable of functional reinnervation of distal muscle targets, whether regenerating through a microchannel device or after direct end-to-end repair. Discrete stimulation-evoked and volitional potentials were recorded within interface microchannels in a small group of awake and behaving animals and their firing patterns correlated directly with intramuscular recordings during locomotion. Of 38 potentials extracted, 19 were identified as motor axons reinnervating tibialis anterior or soleus muscles using spike triggered averaging. Significance. These results are evidence for motor axon regeneration through microchannels and are the first report of in vivo recordings from regenerated motor axons within microchannels in a small

  20. Long-term Potentiation of Perforant Pathway-dentate Gyrus Synapse in Freely Behaving Mice

    PubMed Central

    Blaise, J. Harry

    2013-01-01

    Studies of long-term potentiation of synaptic efficacy, an activity-dependent synaptic phenomenon having properties that make it attractive as a potential cellular mechanism underlying learning and information storage, have long been used to elucidate the physiology of various neuronal circuits in the hippocampus, amygdala, and other limbic and cortical structures. With this in mind, transgenic mouse models of neurological diseases represent useful platforms to conduct long-term potentiation (LTP) studies to develop a greater understanding of the role of genes in normal and abnormal synaptic communication in neuronal networks involved in learning, emotion and information processing. This article describes methodologies for reliably inducing LTP in the freely behaving mouse. These methodologies can be used in studies of transgenic and knockout freely behaving mouse models of neurodegenerative diseases. PMID:24327052

  1. Imaging large-scale cellular activity in spinal cord of freely behaving mice

    PubMed Central

    Sekiguchi, Kohei J.; Shekhtmeyster, Pavel; Merten, Katharina; Arena, Alexander; Cook, Daniela; Hoffman, Elizabeth; Ngo, Alexander; Nimmerjahn, Axel

    2016-01-01

    Sensory information from mechanoreceptors and nociceptors in the skin plays key roles in adaptive and protective motor behaviours. To date, very little is known about how this information is encoded by spinal cord cell types and their activity patterns, particularly under freely behaving conditions. To enable stable measurement of neuronal and glial cell activity in behaving mice, we have developed fluorescence imaging approaches based on two- and miniaturized one-photon microscopy. We show that distinct cutaneous stimuli activate overlapping ensembles of dorsal horn neurons, and that stimulus type and intensity is encoded at the single-cell level. In contrast, astrocytes show large-scale coordinated calcium responses to intense but not weak sensory inputs. Sensory-evoked activity is potently suppressed by anaesthesia. By revealing the cellular and computational logic of spinal cord networks under behaving conditions, our approach holds promise for better understanding of healthy and aberrant spinal cord processes. PMID:27121084

  2. MATLAB-based automated patch-clamp system for awake behaving mice

    PubMed Central

    Siegel, Jennifer J.; Taylor, William; Chitwood, Raymond A.; Johnston, Daniel

    2015-01-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585–587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8–9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice. PMID:26084901

  3. MATLAB-based automated patch-clamp system for awake behaving mice.

    PubMed

    Desai, Niraj S; Siegel, Jennifer J; Taylor, William; Chitwood, Raymond A; Johnston, Daniel

    2015-08-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585-587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8-9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice.

  4. α1-Adrenergic receptors mediate coordinated Ca2+ signaling of cortical astrocytes in awake, behaving mice.

    PubMed

    Ding, Fengfei; O'Donnell, John; Thrane, Alexander S; Zeppenfeld, Douglas; Kang, Hongyi; Xie, Lulu; Wang, Fushun; Nedergaard, Maiken

    2013-12-01

    Astrocyte Ca2+ signals in awake behaving mice are widespread, coordinated and differ fundamentally from the locally restricted Ca2+ transients observed ex vivo and in anesthetized animals. Here we show that the synchronized release of norepinephrine (NE) from locus coeruleus (LC) projections throughout the cerebral cortex mediate long-ranging Ca2+ signals by activation of astrocytic α1-adrenergic receptors. When LC output was triggered by either physiological sensory (whisker) stimulation or an air-puff startle response, astrocytes responded with fast Ca2+ transients that encompassed the entire imaged field (positioned over either frontal or parietal cortex). The application of adrenergic inhibitors, including α1-adrenergic antagonist prazosin, potently suppressed both evoked, as well as the frequently observed spontaneous astroglial Ca2+ signals. The LC-specific neurotoxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), which reduced cortical NE content by >90%, prevented nearly all astrocytic Ca2+ signals in awake mice. The observations indicate that in adult, unanesthetized mice, astrocytes do not respond directly to glutamatergic signaling evoked by sensory stimulation. Instead astrocytes appear to be the primary target for NE, with astrocytic Ca2+ signaling being triggered by the α1-adrenergic receptor. In turn, astrocytes may coordinate the broad effects of neuromodulators on neuronal activity.

  5. Action Potential Waveform Variability Limits Multi-Unit Separation in Freely Behaving Rats

    PubMed Central

    Stratton, Peter; Cheung, Allen; Wiles, Janet; Kiyatkin, Eugene; Sah, Pankaj; Windels, François

    2012-01-01

    Extracellular multi-unit recording is a widely used technique to study spontaneous and evoked neuronal activity in awake behaving animals. These recordings are done using either single-wire or mulitwire electrodes such as tetrodes. In this study we have tested the ability of single-wire electrodes to discriminate activity from multiple neurons under conditions of varying noise and neuronal cell density. Using extracellular single-unit recording, coupled with iontophoresis to drive cell activity across a wide dynamic range, we studied spike waveform variability, and explored systematic differences in single-unit spike waveform within and between brain regions as well as the influence of signal-to-noise ratio (SNR) on the similarity of spike waveforms. We also modelled spike misclassification for a range of cell densities based on neuronal recordings obtained at different SNRs. Modelling predictions were confirmed by classifying spike waveforms from multiple cells with various SNRs using a leading commercial spike-sorting system. Our results show that for single-wire recordings, multiple units can only be reliably distinguished under conditions of high recording SNR (≥4) and low neuronal density (≈20,000/ mm3). Physiological and behavioural changes, as well as technical limitations typical of awake animal preparations, reduce the accuracy of single-channel spike classification, resulting in serious classification errors. For SNR <4, the probability of misclassifying spikes approaches 100% in many cases. Our results suggest that in studies where the SNR is low or neuronal density is high, separation of distinct units needs to be evaluated with great caution. PMID:22719894

  6. Decoding of Intentional Actions from Scalp Electroencephalography (EEG) in Freely-behaving Infants

    PubMed Central

    Hernandez, Zachery R.; Cruz-Garza, Jesus; Tse, Teresa; Contreras-Vidal, Jose L.

    2015-01-01

    The mirror neuron system (MNS) in humans is thought to enable an individual’s understanding of the meaning of actions performed by others and the potential imitation and learning of those actions. In humans, electroencephalographic (EEG) changes in sensorimotor α-band at central electrodes, which desynchronizes both during execution and observation of goal-directed actions (i.e., μ suppression), have been considered an analog to MNS function. However, methodological and developmental issues, as well as the nature of generalized μ suppression to imagined, observed, and performed actions, have yet to provide a mechanistic relationship between EEG μ-rhythm and MNS function, and the extent to which EEG can be used to infer intent during MNS tasks remains unknown. In this study we present a novel methodology using active EEG and inertial sensors to record brain activity and behavioral actions from freely-behaving infants during exploration, imitation, attentive rest, pointing, reaching and grasping, and interaction with an actor. We used δ-band (1–4Hz) EEG as input to a dimensionality reduction algorithm (locality-preserving Fisher’s discriminant analysis, LFDA) followed by a neural classifier (Gaussian mixture models, GMMs) to decode the each MNS task performed by freely-behaving 6–24 month old infants during interaction with an adult actor. Here, we present results from a 20-month male infant to illustrate our approach and show the feasibility of EEG-based classification of freely occurring MNS behaviors displayed by an infant. These results, which provide an alternative to the μ-rhythm theory of MNS function, indicate the informative nature of EEG in relation to intentionality (goal) for MNS tasks which may support action-understanding and thus bear implications for advancing the understanding of MNS function. PMID:25570402

  7. Decoding of intentional actions from scalp electroencephalography (EEG) in freely-behaving infants.

    PubMed

    Hernandez, Zachery R; Cruz-Garza, Jesus; Tse, Teresa; Contreras-Vidal, Jose L

    2014-01-01

    The mirror neuron system (MNS) in humans is thought to enable an individual's understanding of the meaning of actions performed by others and the potential imitation and learning of those actions. In humans, electroencephalographic (EEG) changes in sensorimotor a-band at central electrodes, which desynchronizes both during execution and observation of goal-directed actions (i.e., μ suppression), have been considered an analog to MNS function. However, methodological and developmental issues, as well as the nature of generalized μ suppression to imagined, observed, and performed actions, have yet to provide a mechanistic relationship between EEG μ-rhythm and MNS function, and the extent to which EEG can be used to infer intent during MNS tasks remains unknown. In this study we present a novel methodology using active EEG and inertial sensors to record brain activity and behavioral actions from freely-behaving infants during exploration, imitation, attentive rest, pointing, reaching and grasping, and interaction with an actor. We used 5-band (1-4Hz) EEG as input to a dimensionality reduction algorithm (locality-preserving Fisher's discriminant analysis, LFDA) followed by a neural classifier (Gaussian mixture models, GMMs) to decode the each MNS task performed by freely-behaving 6-24 month old infants during interaction with an adult actor. Here, we present results from a 20-month male infant to illustrate our approach and show the feasibility of EEG-based classification of freely occurring MNS behaviors displayed by an infant. These results, which provide an alternative to the μ-rhythm theory of MNS function, indicate the informative nature of EEG in relation to intentionality (goal) for MNS tasks which may support action-understanding and thus bear implications for advancing the understanding of MNS function.

  8. Tactile responses in the granule cell layer of cerebellar folium crus IIa of freely behaving rats

    NASA Technical Reports Server (NTRS)

    Hartmann, M. J.; Bower, J. M.

    2001-01-01

    We recorded activity from the granule cell layer (GCL) of cerebellar folium Crus IIa as freely moving rats engaged in a variety of natural behaviors, including grooming, eating, and free tactile exploration. Multiunit responses in the 1000-4500 Hz range were found to be strongly correlated with tactile stimulation of lip and whisker (perioral) regions. These responses occurred regardless of whether the stimulus was externally or self-generated and during both active and passive touch. In contrast, perioral movements that did not tactually stimulate this region of the face (e.g., chewing) produced no detectable increases in GCL activity. In addition, GCL responses were not correlated with movement extremes. When rats used their lips actively for palpation and exploration, the tactile responses in the GCL were not detectably modulated by ongoing jaw movements. However, active palpation and exploratory behaviors did result in the largest and most continuous bursts of GCL activity: responses were on average 10% larger and 50% longer during palpation and exploration than during grooming or passive stimulation. Although activity levels differed between behaviors, the position and spatial extent of the peripheral receptive field was similar over all behaviors that resulted in tactile input. Overall, our data suggest that the 1000-4500 Hz multiunit responses in the Crus IIa GCL of awake rats are correlated with tactile input rather than with movement or any movement parameter and that these responses are likely to be of particular importance during the acquisition of sensory information by perioral structures.

  9. Evaluation of a closed loop inductive power transmission system on an awake behaving animal subject.

    PubMed

    Kiani, Mehdi; Kwon, Ki Yong; Zhang, Fei; Oweiss, Karim; Ghovanloo, Maysam

    2011-01-01

    This paper presents in vivo experimental results for a closed loop wireless power transmission system to implantable devices on an awake behaving animal subject. In this system, wireless power transmission takes place across an inductive link, controlled by a commercial off-the-shelf (COTS) radio frequency identification (RFID) transceiver (TRF7960) operating at 13.56 MHz. Induced voltage on the implantable secondary coil is rectified, digitized by a 10-bit analog to digital converter, and transmitted back to the primary via back telemetry. Transmitter (Tx) and receiver (Rx) circuitry were mounted on the back of an adult rat with a nominal distance of ~7 mm between their coils. Our experiments showed that the closed loop system was able to maintain the Rx supply voltage at the designated 3.8 V despite changes in the coils' relative distance and alignment due to animal movements. The Tx power consumption changed between 410 ~ 560 mW in order to deliver 27 mW to the receiver. The open loop system, on the other hand, showed undesired changes in the Rx supply voltage while the Tx power consumption was constant at 660 mW. PMID:22256112

  10. Rodent scope: a user-configurable digital wireless telemetry system for freely behaving animals.

    PubMed

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz-3 kHz) and low frequency field potentials (4 Hz-3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m.

  11. Rodent Scope: A User-Configurable Digital Wireless Telemetry System for Freely Behaving Animals

    PubMed Central

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz–3 kHz) and low frequency field potentials (4 Hz–3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m. PMID:24587144

  12. Rodent scope: a user-configurable digital wireless telemetry system for freely behaving animals.

    PubMed

    Ball, David; Kliese, Russell; Windels, Francois; Nolan, Christopher; Stratton, Peter; Sah, Pankaj; Wiles, Janet

    2014-01-01

    This paper describes the design and implementation of a wireless neural telemetry system that enables new experimental paradigms, such as neural recordings during rodent navigation in large outdoor environments. RoSco, short for Rodent Scope, is a small lightweight user-configurable module suitable for digital wireless recording from freely behaving small animals. Due to the digital transmission technology, RoSco has advantages over most other wireless modules of noise immunity and online user-configurable settings. RoSco digitally transmits entire neural waveforms for 14 of 16 channels at 20 kHz with 8-bit encoding which are streamed to the PC as standard USB audio packets. Up to 31 RoSco wireless modules can coexist in the same environment on non-overlapping independent channels. The design has spatial diversity reception via two antennas, which makes wireless communication resilient to fading and obstacles. In comparison with most existing wireless systems, this system has online user-selectable independent gain control of each channel in 8 factors from 500 to 32,000 times, two selectable ground references from a subset of channels, selectable channel grounding to disable noisy electrodes, and selectable bandwidth suitable for action potentials (300 Hz-3 kHz) and low frequency field potentials (4 Hz-3 kHz). Indoor and outdoor recordings taken from freely behaving rodents are shown to be comparable to a commercial wired system in sorting for neural populations. The module has low input referred noise, battery life of 1.5 hours and transmission losses of 0.1% up to a range of 10 m. PMID:24587144

  13. Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat.

    PubMed

    Alves, Joseph Andrews; Boerner, Barbara Ciralli; Laplagne, Diego Andrés

    2016-01-01

    Quadrupedal mammals typically synchronize their respiration with body movements during rhythmic locomotion. In the rat, fast respiration is coupled to head movements during sniffing behavior, but whether respiration is entrained by stride dynamics is not known. We recorded intranasal pressure, head acceleration, instantaneous speed, and ultrasonic vocalizations from male and female adult rats while freely behaving in a social environment. We used high-speed video recordings of stride to understand how head acceleration signals relate to locomotion and developed techniques to identify episodes of sniffing, walking, trotting, and galloping from the recorded variables. Quantitative analysis of synchrony between respiration and head acceleration rhythms revealed that respiration and locomotion movements were coordinated but with a weaker coupling than expected from previous work in other mammals. We have recently shown that rats behaving in social settings produce high rates of ultrasonic vocalizations during locomotion bouts. Accordingly, rats emitted vocalizations in over half of the respiratory cycles during fast displacements. We present evidence suggesting that emission of these calls disrupts the entrainment of respiration by stride. The coupling between these two variables is thus flexible, such that it can be overridden by other behavioral demands. PMID:27525126

  14. Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat.

    PubMed

    Alves, Joseph Andrews; Boerner, Barbara Ciralli; Laplagne, Diego Andrés

    2016-01-01

    Quadrupedal mammals typically synchronize their respiration with body movements during rhythmic locomotion. In the rat, fast respiration is coupled to head movements during sniffing behavior, but whether respiration is entrained by stride dynamics is not known. We recorded intranasal pressure, head acceleration, instantaneous speed, and ultrasonic vocalizations from male and female adult rats while freely behaving in a social environment. We used high-speed video recordings of stride to understand how head acceleration signals relate to locomotion and developed techniques to identify episodes of sniffing, walking, trotting, and galloping from the recorded variables. Quantitative analysis of synchrony between respiration and head acceleration rhythms revealed that respiration and locomotion movements were coordinated but with a weaker coupling than expected from previous work in other mammals. We have recently shown that rats behaving in social settings produce high rates of ultrasonic vocalizations during locomotion bouts. Accordingly, rats emitted vocalizations in over half of the respiratory cycles during fast displacements. We present evidence suggesting that emission of these calls disrupts the entrainment of respiration by stride. The coupling between these two variables is thus flexible, such that it can be overridden by other behavioral demands.

  15. Flexible Coupling of Respiration and Vocalizations with Locomotion and Head Movements in the Freely Behaving Rat

    PubMed Central

    Alves, Joseph Andrews; Boerner, Barbara Ciralli

    2016-01-01

    Quadrupedal mammals typically synchronize their respiration with body movements during rhythmic locomotion. In the rat, fast respiration is coupled to head movements during sniffing behavior, but whether respiration is entrained by stride dynamics is not known. We recorded intranasal pressure, head acceleration, instantaneous speed, and ultrasonic vocalizations from male and female adult rats while freely behaving in a social environment. We used high-speed video recordings of stride to understand how head acceleration signals relate to locomotion and developed techniques to identify episodes of sniffing, walking, trotting, and galloping from the recorded variables. Quantitative analysis of synchrony between respiration and head acceleration rhythms revealed that respiration and locomotion movements were coordinated but with a weaker coupling than expected from previous work in other mammals. We have recently shown that rats behaving in social settings produce high rates of ultrasonic vocalizations during locomotion bouts. Accordingly, rats emitted vocalizations in over half of the respiratory cycles during fast displacements. We present evidence suggesting that emission of these calls disrupts the entrainment of respiration by stride. The coupling between these two variables is thus flexible, such that it can be overridden by other behavioral demands. PMID:27525126

  16. Anesthetized- and awake-patched whole-cell recordings in freely moving rats using UV-cured collar-based electrode stabilization.

    PubMed

    Lee, Doyun; Shtengel, Gleb; Osborne, Jason E; Lee, Albert K

    2014-12-01

    Intracellular recording allows precise measurement and manipulation of individual neurons, but it requires stable mechanical contact between the electrode and the cell membrane, and thus it has remained challenging to perform in behaving animals. Whole-cell recordings in freely moving animals can be obtained by rigidly fixing ('anchoring') the pipette electrode to the head; however, previous anchoring procedures were slow and often caused substantial pipette movement, resulting in loss of the recording or of recording quality. We describe a UV-transparent collar and UV-cured adhesive technique that rapidly (within 15 s) anchors pipettes in place with virtually no movement, thus substantially improving the reliability, yield and quality of freely moving whole-cell recordings. Recordings are first obtained from anesthetized or awake head-fixed rats. UV light cures the thin adhesive layers linking pipette to collar to head. Then, the animals are rapidly and smoothly released for recording during unrestrained behavior. The anesthetized-patched version can be completed in ∼4-7 h (excluding histology) and the awake-patched version requires ∼1-4 h per day for ∼2 weeks. These advances should greatly facilitate studies of neuronal integration and plasticity in identified cells during natural behaviors. PMID:25375992

  17. A Wirelessly Powered and Controlled Device for Optical Neural Control of Freely-Behaving Animals

    PubMed Central

    Wentz, Christian T.; Bernstein, Jacob G.; Monahan, Patrick; Guerra, Alexander; Rodriguez, Alex; Boyden, Edward S.

    2011-01-01

    Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists’ capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted LED, tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the high-frequency pulse trains often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 grams capable of wirelessly receiving power using a resonant RF power link and storing the energy in an adaptive supercapacitor circuit, which can algorithmically control one or more headborne LEDs via a microcontroller. The device can deliver approximately 2W of power to the LEDs in steady state, and 4.3W in bursts. We also present an optional radio transceiver module (1 gram) which, when added to the base headborne device, enables real-time updating of light delivery protocols; dozens of devices can be simultaneously controlled from one computer. We demonstrate use of the technology to wirelessly drive cortical control of movement in mice. These devices may serve as prototypes for clinical ultra-precise neural prosthetics that use light as the modality of biological control. PMID:21701058

  18. A wirelessly powered and controlled device for optical neural control of freely-behaving animals

    NASA Astrophysics Data System (ADS)

    Wentz, Christian T.; Bernstein, Jacob G.; Monahan, Patrick; Guerra, Alexander; Rodriguez, Alex; Boyden, Edward S.

    2011-08-01

    Optogenetics, the ability to use light to activate and silence specific neuron types within neural networks in vivo and in vitro, is revolutionizing neuroscientists' capacity to understand how defined neural circuit elements contribute to normal and pathological brain functions. Typically, awake behaving experiments are conducted by inserting an optical fiber into the brain, tethered to a remote laser, or by utilizing an implanted light-emitting diode (LED), tethered to a remote power source. A fully wireless system would enable chronic or longitudinal experiments where long duration tethering is impractical, and would also support high-throughput experimentation. However, the high power requirements of light sources (LEDs, lasers), especially in the context of the extended illumination periods often desired in experiments, precludes battery-powered approaches from being widely applicable. We have developed a headborne device weighing 2 g capable of wirelessly receiving power using a resonant RF power link and storing the energy in an adaptive supercapacitor circuit, which can algorithmically control one or more headborne LEDs via a microcontroller. The device can deliver approximately 2 W of power to the LEDs in steady state, and 4.3 W in bursts. We also present an optional radio transceiver module (1 g) which, when added to the base headborne device, enables real-time updating of light delivery protocols; dozens of devices can be controlled simultaneously from one computer. We demonstrate use of the technology to wirelessly drive cortical control of movement in mice. These devices may serve as prototypes for clinical ultra-precise neural prosthetics that use light as the modality of biological control.

  19. 512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice

    PubMed Central

    Xie, Kun; Fox, Grace E.; Liu, Jun; Tsien, Joe Z.

    2016-01-01

    The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse’s small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages – namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli – such as an earthquake and fear-inducing foot-shock – trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors. PMID:27378865

  20. 512-Channel and 13-Region Simultaneous Recordings Coupled with Optogenetic Manipulation in Freely Behaving Mice.

    PubMed

    Xie, Kun; Fox, Grace E; Liu, Jun; Tsien, Joe Z

    2016-01-01

    The development of technologies capable of recording both single-unit activity and local field potentials (LFPs) over a wide range of brain circuits in freely behaving animals is the key to constructing brain activity maps. Although mice are the most popular mammalian genetic model, in vivo neural recording has been traditionally limited to smaller channel count and fewer brain structures because of the mouse's small size and thin skull. Here, we describe a 512-channel tetrode system that allows us to record simultaneously over a dozen cortical and subcortical structures in behaving mice. This new technique offers two major advantages - namely, the ultra-low cost and the do-it-yourself flexibility for targeting any combination of many brain areas. We show the successful recordings of both single units and LFPs from 13 distinct neural circuits of the mouse brain, including subregions of the anterior cingulate cortices, retrosplenial cortices, somatosensory cortices, secondary auditory cortex, hippocampal CA1, dentate gyrus, subiculum, lateral entorhinal cortex, perirhinal cortex, and prelimbic cortex. This 512-channel system can also be combined with Cre-lox neurogenetics and optogenetics to further examine interactions between genes, cell types, and circuit dynamics across a wide range of brain structures. Finally, we demonstrate that complex stimuli - such as an earthquake and fear-inducing foot-shock - trigger firing changes in all of the 13 brain regions recorded, supporting the notion that neural code is highly distributed. In addition, we show that localized optogenetic manipulation in any given brain region could disrupt network oscillations and caused changes in single-unit firing patterns in a brain-wide manner, thereby raising the cautionary note of the interpretation of optogenetically manipulated behaviors. PMID:27378865

  1. Construction of Microdrive Arrays for Chronic Neural Recordings in Awake Behaving Mice

    PubMed Central

    Chang, Eric H.; Frattini, Stephen A.; Robbiati, Sergio; Huerta, Patricio T.

    2013-01-01

    State-of-the-art electrophysiological recordings from the brains of freely behaving animals allow researchers to simultaneously examine local field potentials (LFPs) from populations of neurons and action potentials from individual cells, as the animal engages in experimentally relevant tasks. Chronically implanted microdrives allow for brain recordings to last over periods of several weeks. Miniaturized drives and lightweight components allow for these long-term recordings to occur in small mammals, such as mice. By using tetrodes, which consist of tightly braided bundles of four electrodes in which each wire has a diameter of 12.5 μm, it is possible to isolate physiologically active neurons in superficial brain regions such as the cerebral cortex, dorsal hippocampus, and subiculum, as well as deeper regions such as the striatum and the amygdala. Moreover, this technique insures stable, high-fidelity neural recordings as the animal is challenged with a variety of behavioral tasks. This manuscript describes several techniques that have been optimized to record from the mouse brain. First, we show how to fabricate tetrodes, load them into driveable tubes, and gold-plate their tips in order to reduce their impedance from MΩ to KΩ range. Second, we show how to construct a custom microdrive assembly for carrying and moving the tetrodes vertically, with the use of inexpensive materials. Third, we show the steps for assembling a commercially available microdrive (Neuralynx VersaDrive) that is designed to carry independently movable tetrodes. Finally, we present representative results of local field potentials and single-unit signals obtained in the dorsal subiculum of mice. These techniques can be easily modified to accommodate different types of electrode arrays and recording schemes in the mouse brain. PMID:23851569

  2. Feeding and diurnal related activity of lateral hypothalamic neurons in freely behaving rats.

    PubMed

    Ono, T; Sasaki, K; Nishino, H; Fukuda, M; Shibata, R

    1986-05-14

    Activity of 64 single neurons in the lateral hypothalamus (LHA) was recorded for 1-8 days in freely behaving rats. The activity of 26 (40.6%) neurons varied with circadian rhythm and in relation to feeding. Activity of 23 of these neurons decreased during consumption of each pellet, and that of one increased. The activity of two other neurons increased intermittently, at night, prior to and during eating and drinking episodes. All changed activity with sleep-wake changes; increasing in the dark or upon arousal, and decreasing in the light or during slow wave sleep, but the activity was independent of individual movement, except feeding. The activity of 29 (45.3%) neurons varied only diurnally. Of these, 26 neurons also had sleep-wake responses and activity changes that corresponded to behavior. The firing rate of the other 3 neurons was independent of sleep-wake condition or individual feeding activity, but gradually increased in the dark to a maximum in the early morning, then subsided rapidly in 1-2 h. Four (6.3%) neurons were related only to feeding and not to diurnal rhythm, and 5 (7.8%) neurons were not related to either. Of the 5 neurons that were unrelated to either diurnal rhythm or feeding acts, 3 increased activity at light on and decreased it at light off for 4-13 min. These data suggest LHA neuronal involvement in control of short term feeding or individual feeding episodes, and long term feeding or circadian feeding rhythm.

  3. Head-mounted LED for optogenetic experiments of freely-behaving animal

    NASA Astrophysics Data System (ADS)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  4. Imaging Circulating Tumor Cells in Freely Moving Awake Small Animals Using a Miniaturized Intravital Microscope

    PubMed Central

    Sasportas, Laura Sarah; Gambhir, Sanjiv Sam

    2014-01-01

    Metastasis, the cause for 90% of cancer mortality, is a complex and poorly understood process involving the invasion of circulating tumor cells (CTCs) into blood vessels. These cells have potential prognostic value as biomarkers for early metastatic risk. But their rarity and the lack of specificity and sensitivity in measuring them render their interrogation by current techniques very challenging. How and when these cells are circulating in the blood, on their way to potentially give rise to metastasis, is a question that remains largely unanswered. In order to provide an insight into this "black box" using non-invasive imaging, we developed a novel miniature intravital microscopy (mIVM) strategy capable of real-time long-term monitoring of CTCs in awake small animals. We established an experimental 4T1-GL mouse model of metastatic breast cancer, in which tumor cells express both fluorescent and bioluminescent reporter genes to enable both single cell and whole body tumor imaging. Using mIVM, we monitored blood vessels of different diameters in awake mice in an experimental model of metastasis. Using an in-house software algorithm we developed, we demonstrated in vivo CTC enumeration and computation of CTC trajectory and speed. These data represent the first reported use we know of for a miniature mountable intravital microscopy setup for in vivo imaging of CTCs in awake animals. PMID:24497977

  5. Coherent 25- to 35-Hz Oscillations in the Sensorimotor Cortex of Awake Behaving Monkeys

    NASA Astrophysics Data System (ADS)

    Murthy, Venkatesh N.; Fetz, Eberhard E.

    1992-06-01

    Synchronous 25- to 35-Hz oscillations were observed in local field potentials and unit activity in sensorimotor cortex of awake rhesus monkeys. The oscillatory episodes occurred often when the monkeys retrieved raisins from a Kluver board or from unseen locations using somatosensory feedback; they occurred less often during performance of repetitive wrist flexion and extension movements. The amplitude, duration, and frequency of oscillations were not directly related to movement parameters in behaviors studied so far. The occurrence of the oscillations was not consistently related to bursts of activity in forearm muscles, but cycle-triggered averages of electromyograms revealed synchronous modulation in flexor and extensor muscles. The phase of the oscillations changed continuously from the surface to the deeper layers of the cortex, reversing their polarity completely at depths exceeding 800 μm. The oscillations could become synchronized over a distance of 14 mm mediolaterally in precentral cortex. Coherent oscillations could also occur at pre- and postcentral sites separated by an estimated tangential intracortical distance of 20 mm. Activity of single units was commonly seen to burst in synchrony with field potential oscillations. These findings suggest that such oscillations may facilitate interactions between cells during exploratory and manipulative movements, requiring attention to sensorimotor integration.

  6. A wireless neural recording system with a precision motorized microdrive for freely behaving animals

    PubMed Central

    Hasegawa, Taku; Fujimoto, Hisataka; Tashiro, Koichiro; Nonomura, Mayu; Tsuchiya, Akira; Watanabe, Dai

    2015-01-01

    The brain is composed of many different types of neurons. Therefore, analysis of brain activity with single-cell resolution could provide fundamental insights into brain mechanisms. However, the electrical signal of an individual neuron is very small, and precise isolation of single neuronal activity from moving subjects is still challenging. To measure single-unit signals in actively behaving states, establishment of technologies that enable fine control of electrode positioning and strict spike sorting is essential. To further apply such a single-cell recording approach to small brain areas in naturally behaving animals in large spaces or during social interaction, we developed a compact wireless recording system with a motorized microdrive. Wireless control of electrode placement facilitates the exploration of single neuronal activity without affecting animal behaviors. Because the system is equipped with a newly developed data-encoding program, the recorded data are readily compressed almost to theoretical limits and securely transmitted to a host computer. Brain activity can thereby be stably monitored in real time and further analyzed using online or offline spike sorting. Our wireless recording approach using a precision motorized microdrive will become a powerful tool for studying brain mechanisms underlying natural or social behaviors. PMID:25597933

  7. A wireless neural recording system with a precision motorized microdrive for freely behaving animals.

    PubMed

    Hasegawa, Taku; Fujimoto, Hisataka; Tashiro, Koichiro; Nonomura, Mayu; Tsuchiya, Akira; Watanabe, Dai

    2015-01-01

    The brain is composed of many different types of neurons. Therefore, analysis of brain activity with single-cell resolution could provide fundamental insights into brain mechanisms. However, the electrical signal of an individual neuron is very small, and precise isolation of single neuronal activity from moving subjects is still challenging. To measure single-unit signals in actively behaving states, establishment of technologies that enable fine control of electrode positioning and strict spike sorting is essential. To further apply such a single-cell recording approach to small brain areas in naturally behaving animals in large spaces or during social interaction, we developed a compact wireless recording system with a motorized microdrive. Wireless control of electrode placement facilitates the exploration of single neuronal activity without affecting animal behaviors. Because the system is equipped with a newly developed data-encoding program, the recorded data are readily compressed almost to theoretical limits and securely transmitted to a host computer. Brain activity can thereby be stably monitored in real time and further analyzed using online or offline spike sorting. Our wireless recording approach using a precision motorized microdrive will become a powerful tool for studying brain mechanisms underlying natural or social behaviors. PMID:25597933

  8. A Wireless Multi-Channel Recording System for Freely Behaving Mice and Rats

    PubMed Central

    Holtzman, Tahl; Ruther, Patrick; Dalley, Jeffrey W.; Lopez, Alberto; Rossi, Mark A.; Barter, Joseph W.; Salas-Meza, Daniel; Herwik, Stanislav; Holzhammer, Tobias; Morizio, James; Yin, Henry H.

    2011-01-01

    To understand the neural basis of behavior, it is necessary to record brain activity in freely moving animals. Advances in implantable multi-electrode array technology have enabled researchers to record the activity of neuronal ensembles from multiple brain regions. The full potential of this approach is currently limited by reliance on cable tethers, with bundles of wires connecting the implanted electrodes to the data acquisition system while impeding the natural behavior of the animal. To overcome these limitations, here we introduce a multi-channel wireless headstage system designed for small animals such as rats and mice. A variety of single unit and local field potential signals were recorded from the dorsal striatum and substantia nigra in mice and the ventral striatum and prefrontal cortex simultaneously in rats. This wireless system could be interfaced with commercially available data acquisition systems, and the signals obtained were comparable in quality to those acquired using cable tethers. On account of its small size, light weight, and rechargeable battery, this wireless headstage system is suitable for studying the neural basis of natural behavior, eliminating the need for wires, commutators, and other limitations associated with traditional tethered recording systems. PMID:21765934

  9. An Arbitrary Waveform Wearable Neuro-stimulator System for Neurophysiology Research on Freely Behaving Animals.

    PubMed

    Samani, Mohsen Mosayebi; Mahnam, Amin; Hosseini, Nasrin

    2014-04-01

    Portable wireless neuro-stimulators have been developed to facilitate long-term cognitive and behavioral studies on the central nervous system in freely moving animals. These stimulators can provide precisely controllable input(s) to the nervous system, without distracting the animal attention with cables connected to its body. In this study, a low power backpack neuro-stimulator was developed for animal brain researches that can provides arbitrary stimulus waveforms for the stimulation, while it is small and light weight to be used for small animals including rats. The system consists of a controller that uses an RF link to program and activate a small and light microprocessor-based stimulator. A Howland current source was implemented to produce precise current controlled arbitrary waveform stimulations. The system was optimized for ultra-low power consumption and small size. The stimulator was first tested for its electrical specifications. Then its performance was evaluated in a rat experiment when electrical stimulation of medial longitudinal fasciculus induced circling behavior. The stimulator is capable of delivering programmed stimulations up to ± 2 mA with adjusting steps of 1 μA, accuracy of 0.7% and compliance of 6 V. The stimulator is 15 mm × 20 mm × 40 mm in size, weights 13.5 g without battery and consumes a total power of only 5.l mW. In the experiment, the rat could easily carry the stimulator and demonstrated the circling behavior for 0.1 ms current pulses of above 400 μA. The developed system has a competitive size and weight, whereas providing a wide range of operation and the flexibility of generating arbitrary stimulation patterns ideal for long-term experiments in the field of cognitive and neuroscience research.

  10. Awake behaving electrophysiological correlates of forelimb hyperreflexia, weakness and disrupted muscular synchronization following cervical spinal cord injury in the rat.

    PubMed

    Ganzer, Patrick Daniel; Meyers, Eric Christopher; Sloan, Andrew Michael; Maliakkal, Reshma; Ruiz, Andrea; Kilgard, Michael Paul; Robert, LeMoine Rennaker

    2016-07-01

    Spinal cord injury usually occurs at the level of the cervical spine and results in profound impairment of forelimb function. In this study, we recorded awake behaving intramuscular electromyography (EMG) from the biceps and triceps muscles of the impaired forelimb during volitional and reflexive forelimb movements before and after unilateral cervical spinal cord injury (cSCI) in rats. C5/C6 hemicontusion reduced volitional forelimb strength by more than 50% despite weekly rehabilitation for one month post-injury. Triceps EMG during volitional strength assessment was reduced by more than 60% following injury, indicating reduced descending drive. Biceps EMG during reflexive withdrawal from a thermal stimulus was increased by 500% following injury, indicating flexor withdrawal hyperreflexia. The reduction in volitional forelimb strength was significantly correlated with volitional and reflexive biceps EMG activity. Our results support the hypothesis that biceps hyperreflexia and descending volitional drive both significantly contribute to forelimb strength deficits after cSCI and provide new insight into dynamic muscular dysfunction after cSCI. The use of multiple automated quantitative measures of forelimb dysfunction in the rodent cSCI model will likely aid the search for effective regenerative, pharmacological, and neuroprosthetic treatments for spinal cord injury. PMID:27033345

  11. Awake behaving electrophysiological correlates of forelimb hyperreflexia, weakness and disrupted muscular synchronization following cervical spinal cord injury in the rat.

    PubMed

    Ganzer, Patrick Daniel; Meyers, Eric Christopher; Sloan, Andrew Michael; Maliakkal, Reshma; Ruiz, Andrea; Kilgard, Michael Paul; Robert, LeMoine Rennaker

    2016-07-01

    Spinal cord injury usually occurs at the level of the cervical spine and results in profound impairment of forelimb function. In this study, we recorded awake behaving intramuscular electromyography (EMG) from the biceps and triceps muscles of the impaired forelimb during volitional and reflexive forelimb movements before and after unilateral cervical spinal cord injury (cSCI) in rats. C5/C6 hemicontusion reduced volitional forelimb strength by more than 50% despite weekly rehabilitation for one month post-injury. Triceps EMG during volitional strength assessment was reduced by more than 60% following injury, indicating reduced descending drive. Biceps EMG during reflexive withdrawal from a thermal stimulus was increased by 500% following injury, indicating flexor withdrawal hyperreflexia. The reduction in volitional forelimb strength was significantly correlated with volitional and reflexive biceps EMG activity. Our results support the hypothesis that biceps hyperreflexia and descending volitional drive both significantly contribute to forelimb strength deficits after cSCI and provide new insight into dynamic muscular dysfunction after cSCI. The use of multiple automated quantitative measures of forelimb dysfunction in the rodent cSCI model will likely aid the search for effective regenerative, pharmacological, and neuroprosthetic treatments for spinal cord injury.

  12. A Chronic Implant to Record Electroretinogram, Visual Evoked Potentials and Oscillatory Potentials in Awake, Freely Moving Rats for Pharmacological Studies

    PubMed Central

    Guarino, Irene; Loizzo, Stefano; Lopez, Luisa; Fadda, Antonello; Loizzo, Alberto

    2004-01-01

    Electroretinogram (ERG), widely used to study the pharmacological effects of drugs in animal models (e.g., diabetic retinopathy), is usually recorded in anesthetized rats. We report here a novel simple method to obtain chronic implantation of electrodes for simultaneous recording at the retinal and cortical levels in freely moving, unanesthetized animals. We recorded cortical (VEPs) and retinal (ERGs) responses evoked by light (flash) stimuli in awake rats and compared the results in the same rats anesthetized with urethane (0.6 mg/kg) before and after the monocular administration of scopolamine methyl bromide (1‰solution). We also compared the retinal responses with those derived from a classic acute corneal electrode. Anesthesia induced consistent changes of several VEP and ERG parameters like an increase of both latency and amplitude. In particular, the analysis of the variation of latency, amplitude, and spectral content of rapid oscillatory potentials could be important for a functional evaluation of the visual system in unanesthetized versus anesthetized animals. PMID:15656271

  13. Prosthetic Avian Vocal Organ Controlled by a Freely Behaving Bird Based on a Low Dimensional Model of the Biomechanical Periphery

    PubMed Central

    Arneodo, Ezequiel M.; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B.

    2012-01-01

    Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform. PMID:22761555

  14. Prosthetic avian vocal organ controlled by a freely behaving bird based on a low dimensional model of the biomechanical periphery.

    PubMed

    Arneodo, Ezequiel M; Perl, Yonatan Sanz; Goller, Franz; Mindlin, Gabriel B

    2012-01-01

    Because of the parallels found with human language production and acquisition, birdsong is an ideal animal model to study general mechanisms underlying complex, learned motor behavior. The rich and diverse vocalizations of songbirds emerge as a result of the interaction between a pattern generator in the brain and a highly nontrivial nonlinear periphery. Much of the complexity of this vocal behavior has been understood by studying the physics of the avian vocal organ, particularly the syrinx. A mathematical model describing the complex periphery as a nonlinear dynamical system leads to the conclusion that nontrivial behavior emerges even when the organ is commanded by simple motor instructions: smooth paths in a low dimensional parameter space. An analysis of the model provides insight into which parameters are responsible for generating a rich variety of diverse vocalizations, and what the physiological meaning of these parameters is. By recording the physiological motor instructions elicited by a spontaneously singing muted bird and computing the model on a Digital Signal Processor in real-time, we produce realistic synthetic vocalizations that replace the bird's own auditory feedback. In this way, we build a bio-prosthetic avian vocal organ driven by a freely behaving bird via its physiologically coded motor commands. Since it is based on a low-dimensional nonlinear mathematical model of the peripheral effector, the emulation of the motor behavior requires light computation, in such a way that our bio-prosthetic device can be implemented on a portable platform. PMID:22761555

  15. Afferent Input Selects NMDA Receptor Subtype to Determine the Persistency of Hippocampal LTP in Freely Behaving Mice

    PubMed Central

    Ballesteros, Jesús J.; Buschler, Arne; Köhr, Georg; Manahan-Vaughan, Denise

    2016-01-01

    The glutamatergic N-methyl-D-aspartate receptor (NMDAR) is critically involved in many forms of hippocampus-dependent memory that may be enabled by synaptic plasticity. Behavioral studies with NMDAR antagonists and NMDAR subunit (GluN2) mutants revealed distinct contributions from GluN2A- and GluN2B-containing NMDARs to rapidly and slowly acquired memory performance. Furthermore, studies of synaptic plasticity, in genetically modified mice in vitro, suggest that GluN2A and GluN2B may contribute in different ways to the induction and longevity of synaptic plasticity. In contrast to the hippocampal slice preparation, in behaving mice, the afferent frequencies that induce synaptic plasticity are very restricted and specific. In fact, it is the stimulus pattern and not variations in afferent frequency that determine the longevity of long-term potentiation (LTP) in vivo. Here, we explored the contribution of GluN2A and GluN2B to LTP of differing magnitudes and persistence in freely behaving mice. We applied differing high-frequency stimulation (HFS) patterns at 100 Hz to the hippocampal CA1 region, to induce NMDAR-dependent LTP in wild-type (WT) mice, that endured for <1 h (early (E)-LTP), (LTP, 2–4 h) or >24 h (late (L)-LTP). In GluN2A-knockout (KO) mice, E-LTP (HFS, 50 pulses) was significantly reduced in magnitude and duration, whereas LTP (HFS, 2 × 50 pulses) and L-LTP (HFS, 4 × 50 pulses) were unaffected compared to responses in WT animals. By contrast, pharmacological antagonism of GluN2B in WT had no effect on E-LTP but significantly prevented LTP. E-LTP and LTP were significantly impaired by GluN2B antagonism in GluN2A-KO mice. These data indicate that the pattern of afferent stimulation is decisive for the recruitment of distinct GluN2A and GluN2B signaling pathways that in turn determine the persistency of hippocampal LTP. Whereas brief bursts of patterned stimulation preferentially recruit GluN2A and lead to weak and short-lived forms of LTP, prolonged

  16. Long-term expression of two interacting motor pattern-generating networks in the stomatogastric system of freely behaving lobster.

    PubMed

    Clemens, S; Combes, D; Meyrand, P; Simmers, J

    1998-03-01

    Rhythmic movements of the gastric mill and pyloric regions of the crustacean foregut are controlled by two stomatogastric neuronal networks that have been intensively studied in vitro. By using electromyographic recordings from the European lobster, Homarus gammarus, we have monitored simultaneously the motor activity of pyloric and gastric mill muscles for freely behaving animals. Both pyloric and gastric mill networks are almost continuously active in vivo regardless of the presence of food. In unfed resting animals kept under "natural-like" conditions, the pyloric network expresses the typical triphasic pattern seen in vitro but at considerably slower cycle periods (2. 5-3.5 s instead of 1-1.5 s). Gastric mill activity occurs at mean cycle periods of 20-50 s compared with 5-10 s in vitro but may suddenly stop for up to tens of minutes, then restart without any apparent behavioral reason. When conjointly active, the two networks express a strict coupling that involves certain but not all motor neurons of the pyloric network. The posterior pyloric constrictor muscles, innervated by a total of 8 pyloric (PY) motor neurons, are influenced by the onset of each gastric mill medial gastric/lateral gastric(MG/LG) neuron powerstroke burst, and for one cycle, PY neuron bursts may attain >300% of their mean duration. However, the duration of activity in the lateral pyloric constrictor muscle, innervated by the unique lateral pyloric (LP) motor neuron, remains unaffected by this perturbation. During this period after gastric perturbation, LP neuron and PY neurons thus express opposite burst-to-period relationships in that LP neuron burst duration is independent of the ongoing cycle period, whereas PY neuron burst duration changes with period length. In vitro the same type of gastro-pyloric interaction is observed, indicating that it is not dependent on sensory inputs. Moreover, this interaction is intrinsic to the stomatogastric ganglion itself because

  17. A movable microelectrode array for chronic basal ganglia single-unit electrocorticogram co-recording in freely behaving rats.

    PubMed

    Zheng, Xiaobin; Zeng, Jia; Chen, Ting; Lin, Yuanxiang; Yu, Lianghong; Li, Ying; Lin, Zhangya; Wu, Xiyue; Chen, Fuyong; Kang, Dezhi; Zhang, Shizhong

    2014-09-01

    The basal ganglia-cortical circuits are important for information process to brain function. However, chronic recording of single-unit activities in the basal ganglia nucleus has not yet been well established. We present a movable bundled microwire array for chronic subthalamic nucleus (STN) single-unit electrocorticogram co-recording. The electrode assembly contains a screw-advanced microdrive and a microwire array. The array consists of a steel guide tube, five recording wires and one referenced wire which form the shape of a guiding hand, and one screw electrode for cortico-recording. The electrode can acquire stable cortex oscillation-driven STN firing units in rats under different behaving conditions for 8 weeks. We achieved satisfying signal-to-noise ratio, portions of cells retaining viability, and spike waveform similarities across the recording sections. Using this method, we investigated neural correlations of the basal ganglia-cortical circuits in different behaving conditions. This method will become a powerful tool for multi-region recording to study normal statements or movement disorders.

  18. Mechanical characteristics of rat vibrissae: resonant frequencies and damping in isolated whiskers and in the awake behaving animal

    NASA Technical Reports Server (NTRS)

    Hartmann, Mitra J.; Johnson, Nicholas J.; Towal, R. Blythe; Assad, Christopher

    2003-01-01

    We investigated the natural resonance properties and damping characteristics of rat macrovibrissae (whiskers). Isolated whiskers rigidly fixed at the base showed first-mode resonance peaks between 27 and 260 Hz, principally depending on whisker length. These experimentally measured resonant frequencies were matched using a theoretical model of the whisker as a conical cantilever beam, with Young's modulus as the only free parameter. The best estimate for Young's modulus was approximately 3-4 GPa. Results of both vibration and impulse experiments showed that the whiskers are strongly damped, with damping ratios between 0.11 and 0.17. In the behaving animal, whiskers that deflected past an object were observed to resonate but were damped significantly more than isolated whiskers. The time course of damping varied depending on the individual whisker and the phase of the whisking cycle, which suggests that the rat may modulate biomechanical parameters that affect damping. No resonances were observed for whiskers that did not contact the object or during free whisking in air. Finally, whiskers on the same side of the face were sometimes observed to move in opposite directions over the full duration of a whisk. We discuss the potential roles of resonance during natural exploratory behavior and specifically suggest that resonant oscillations may be important in the rat's tactile detection of object boundaries.

  19. Zolpidem Reduces Hippocampal Neuronal Activity in Freely Behaving Mice: A Large Scale Calcium Imaging Study with Miniaturized Fluorescence Microscope

    PubMed Central

    Berdyyeva, Tamara; Otte, Stephani; Aluisio, Leah; Ziv, Yaniv; Burns, Laurie D.; Dugovic, Christine; Yun, Sujin; Ghosh, Kunal K.; Schnitzer, Mark J.; Lovenberg, Timothy; Bonaventure, Pascal

    2014-01-01

    Therapeutic drugs for cognitive and psychiatric disorders are often characterized by their molecular mechanism of action. Here we demonstrate a new approach to elucidate drug action on large-scale neuronal activity by tracking somatic calcium dynamics in hundreds of CA1 hippocampal neurons of pharmacologically manipulated behaving mice. We used an adeno-associated viral vector to express the calcium sensor GCaMP3 in CA1 pyramidal cells under control of the CaMKII promoter and a miniaturized microscope to observe cellular dynamics. We visualized these dynamics with and without a systemic administration of Zolpidem, a GABAA agonist that is the most commonly prescribed drug for the treatment of insomnia in the United States. Despite growing concerns about the potential adverse effects of Zolpidem on memory and cognition, it remained unclear whether Zolpidem alters neuronal activity in the hippocampus, a brain area critical for cognition and memory. Zolpidem, when delivered at a dose known to induce and prolong sleep, strongly suppressed CA1 calcium signaling. The rate of calcium transients after Zolpidem administration was significantly lower compared to vehicle treatment. To factor out the contribution of changes in locomotor or physiological conditions following Zolpidem treatment, we compared the cellular activity across comparable epochs matched by locomotor and physiological assessments. This analysis revealed significantly depressive effects of Zolpidem regardless of the animal’s state. Individual hippocampal CA1 pyramidal cells differed in their responses to Zolpidem with the majority (∼65%) significantly decreasing the rate of calcium transients, and a small subset (3%) showing an unexpected and significant increase. By linking molecular mechanisms with the dynamics of neural circuitry and behavioral states, this approach has the potential to contribute substantially to the development of new therapeutics for the treatment of CNS disorders. PMID:25372144

  20. A Novel Experimental and Analytical Approach to the Multimodal Neural Decoding of Intent During Social Interaction in Freely-behaving Human Infants

    PubMed Central

    Cruz-Garza, Jesus G.; Hernandez, Zachery R.; Tse, Teresa; Caducoy, Eunice; Abibullaev, Berdakh; Contreras-Vidal, Jose L.

    2015-01-01

    Understanding typical and atypical development remains one of the fundamental questions in developmental human neuroscience. Traditionally, experimental paradigms and analysis tools have been limited to constrained laboratory tasks and contexts due to technical limitations imposed by the available set of measuring and analysis techniques and the age of the subjects. These limitations severely limit the study of developmental neural dynamics and associated neural networks engaged in cognition, perception and action in infants performing “in action and in context”. This protocol presents a novel approach to study infants and young children as they freely organize their own behavior, and its consequences in a complex, partly unpredictable and highly dynamic environment. The proposed methodology integrates synchronized high-density active scalp electroencephalography (EEG), inertial measurement units (IMUs), video recording and behavioral analysis to capture brain activity and movement non-invasively in freely-behaving infants. This setup allows for the study of neural network dynamics in the developing brain, in action and context, as these networks are recruited during goal-oriented, exploration and social interaction tasks. PMID:26485409

  1. Integrated wireless fast-scan cyclic voltammetry recording and electrical stimulation for reward-predictive learning in awake, freely moving rats

    NASA Astrophysics Data System (ADS)

    Li, Yu-Ting; Wickens, Jeffery R.; Huang, Yi-Ling; Pan, Wynn H. T.; Chen, Fu-Yu Beverly; Chen, Jia-Jin Jason

    2013-08-01

    Objective. Fast-scan cyclic voltammetry (FSCV) is commonly used to monitor phasic dopamine release, which is usually performed using tethered recording and for limited types of animal behavior. It is necessary to design a wireless dopamine sensing system for animal behavior experiments. Approach. This study integrates a wireless FSCV system for monitoring the dopamine signal in the ventral striatum with an electrical stimulator that induces biphasic current to excite dopaminergic neurons in awake freely moving rats. The measured dopamine signals are unidirectionally transmitted from the wireless FSCV module to the host unit. To reduce electrical artifacts, an optocoupler and a separate power are applied to isolate the FSCV system and electrical stimulator, which can be activated by an infrared controller. Main results. In the validation test, the wireless backpack system has similar performance in comparison with a conventional wired system and it does not significantly affect the locomotor activity of the rat. In the cocaine administration test, the maximum electrically elicited dopamine signals increased to around 230% of the initial value 20 min after the injection of 10 mg kg-1 cocaine. In a classical conditioning test, the dopamine signal in response to a cue increased to around 60 nM over 50 successive trials while the electrically evoked dopamine concentration decreased from about 90 to 50 nM in the maintenance phase. In contrast, the cue-evoked dopamine concentration progressively decreased and the electrically evoked dopamine was eliminated during the extinction phase. In the histological evaluation, there was little damage to brain tissue after five months chronic implantation of the stimulating electrode. Significance. We have developed an integrated wireless voltammetry system for measuring dopamine concentration and providing electrical stimulation. The developed wireless FSCV system is proven to be a useful experimental tool for the continuous

  2. Taste coding of complex naturalistic taste stimuli and traditional taste stimuli in the parabrachial pons of the awake, freely licking rat.

    PubMed

    Sammons, Joshua D; Weiss, Michael S; Victor, Jonathan D; Di Lorenzo, Patricia M

    2016-07-01

    Several studies have shown that taste-responsive cells in the brainstem taste nuclei of rodents respond to sensory qualities other than gustation. Such data suggest that cells in the classical gustatory brainstem may be better tuned to respond to stimuli that engage multiple sensory modalities than to stimuli that are purely gustatory. Here, we test this idea by recording the electrophysiological responses to complex, naturalistic stimuli in single neurons in the parabrachial pons (PbN, the second neural relay in the central gustatory pathway) in awake, freely licking rats. Following electrode implantation and recovery, we presented both prototypical and naturalistic taste stimuli and recorded the responses in the PbN. Prototypical taste stimuli (NaCl, sucrose, citric acid, and caffeine) and naturalistic stimuli (clam juice, grape juice, lemon juice, and coffee) were matched for taste quality and intensity (concentration). Umami (monosodium glutamate + inosine monophosphate) and fat (diluted heavy cream) were also tested. PbN neurons responded to naturalistic stimuli as much or more than to prototypical taste stimuli. Furthermore, they convey more information about naturalistic stimuli than about prototypical ones. Moreover, multidimensional scaling analyses showed that across unit responses to naturalistic stimuli were more widely separated than responses to prototypical taste stimuli. Interestingly, cream evoked a robust and widespread response in PbN cells. Collectively, these data suggest that natural foods are more potent stimulators of PbN cells than purely gustatory stimuli. Probing PbN cells with pure taste stimuli may underestimate the response repertoire of these cells.

  3. Taste coding of complex naturalistic taste stimuli and traditional taste stimuli in the parabrachial pons of the awake, freely licking rat.

    PubMed

    Sammons, Joshua D; Weiss, Michael S; Victor, Jonathan D; Di Lorenzo, Patricia M

    2016-07-01

    Several studies have shown that taste-responsive cells in the brainstem taste nuclei of rodents respond to sensory qualities other than gustation. Such data suggest that cells in the classical gustatory brainstem may be better tuned to respond to stimuli that engage multiple sensory modalities than to stimuli that are purely gustatory. Here, we test this idea by recording the electrophysiological responses to complex, naturalistic stimuli in single neurons in the parabrachial pons (PbN, the second neural relay in the central gustatory pathway) in awake, freely licking rats. Following electrode implantation and recovery, we presented both prototypical and naturalistic taste stimuli and recorded the responses in the PbN. Prototypical taste stimuli (NaCl, sucrose, citric acid, and caffeine) and naturalistic stimuli (clam juice, grape juice, lemon juice, and coffee) were matched for taste quality and intensity (concentration). Umami (monosodium glutamate + inosine monophosphate) and fat (diluted heavy cream) were also tested. PbN neurons responded to naturalistic stimuli as much or more than to prototypical taste stimuli. Furthermore, they convey more information about naturalistic stimuli than about prototypical ones. Moreover, multidimensional scaling analyses showed that across unit responses to naturalistic stimuli were more widely separated than responses to prototypical taste stimuli. Interestingly, cream evoked a robust and widespread response in PbN cells. Collectively, these data suggest that natural foods are more potent stimulators of PbN cells than purely gustatory stimuli. Probing PbN cells with pure taste stimuli may underestimate the response repertoire of these cells. PMID:27121585

  4. Longitudinal testing of hippocampal plasticity reveals the onset and maintenance of endogenous human Aß-induced synaptic dysfunction in individual freely behaving pre-plaque transgenic rats: rapid reversal by anti-Aß agents.

    PubMed

    Qi, Yingjie; Klyubin, Igor; Harney, Sarah C; Hu, NengWei; Cullen, William K; Grant, Marianne K; Steffen, Julia; Wilson, Edward N; Do Carmo, Sonia; Remy, Stefan; Fuhrmann, Martin; Ashe, Karen H; Cuello, A Claudio; Rowan, Michael J

    2014-12-24

    Long before synaptic loss occurs in Alzheimer's disease significant harbingers of disease may be detected at the functional level. Here we examined if synaptic long-term potentiation is selectively disrupted prior to extracellular deposition of Aß in a very complete model of Alzheimer's disease amyloidosis, the McGill-R-Thy1-APP transgenic rat. Longitudinal studies in freely behaving animals revealed an age-dependent, relatively rapid-onset and persistent inhibition of long-term potentiation without a change in baseline synaptic transmission in the CA1 area of the hippocampus. Thus the ability of a standard 200 Hz conditioning protocol to induce significant NMDA receptor-dependent short- and long-term potentiation was lost at about 3.5 months of age and this deficit persisted for at least another 2-3 months, when plaques start to appear. Consistent with in vitro evidence for a causal role of a selective reduction in NMDA receptor-mediated synaptic currents, the deficit in synaptic plasticity in vivo was associated with a reduction in the synaptic burst response to the conditioning stimulation and was overcome using stronger 400 Hz stimulation. Moreover, intracerebroventricular treatment for 3 days with an N-terminally directed monoclonal anti- human Aß antibody, McSA1, transiently reversed the impairment of synaptic plasticity. Similar brief treatment with the BACE1 inhibitor LY2886721 or the γ-secretase inhibitor MRK-560 was found to have a comparable short-lived ameliorative effect when tracked in individual rats. These findings provide strong evidence that endogenously generated human Aß selectively disrupts the induction of long-term potentiation in a manner that enables potential therapeutic options to be assessed longitudinally at the pre-plaque stage of Alzheimer's disease amyloidosis.

  5. Imaging Neuronal Populations in Behaving Rodents: Paradigms for Studying Neural Circuits Underlying Behavior in the Mammalian Cortex

    PubMed Central

    Andermann, Mark L.; Keck, Tara; Xu, Ning-Long; Ziv, Yaniv

    2013-01-01

    Understanding the neural correlates of behavior in the mammalian cortex requires measurements of activity in awake, behaving animals. Rodents have emerged as a powerful model for dissecting the cortical circuits underlying behavior attributable to the convergence of several methods. Genetically encoded calcium indicators combined with viral-mediated or transgenic tools enable chronic monitoring of calcium signals in neuronal populations and subcellular structures of identified cell types. Stable one- and two-photon imaging of neuronal activity in awake, behaving animals is now possible using new behavioral paradigms in head-fixed animals, or using novel miniature head-mounted microscopes in freely moving animals. This mini-symposium will highlight recent applications of these methods for studying sensorimotor integration, decision making, learning, and memory in cortical and subcortical brain areas. We will outline future prospects and challenges for identifying the neural underpinnings of task-dependent behavior using cellular imaging in rodents. PMID:24198355

  6. Acute intracerebral treatment with amyloid-beta (1–42) alters the profile of neuronal oscillations that accompany LTP induction and results in impaired LTP in freely behaving rats

    PubMed Central

    Kalweit, Alexander Nikolai; Yang, Honghong; Colitti-Klausnitzer, Jens; Fülöp, Livia; Bozsó, Zsolt; Penke, Botond; Manahan-Vaughan, Denise

    2015-01-01

    Accumulation of amyloid plaques comprises one of the major hallmarks of Alzheimer’s disease (AD). In rodents, acute treatment with amyloid-beta (Aβ; 1–42) elicits immediate debilitating effects on hippocampal long-term potentiation (LTP). Whereas LTP contributes to synaptic information storage, information is transferred across neurons by means of neuronal oscillations. Furthermore, changes in theta-gamma oscillations, that appear during high-frequency stimulation (HFS) to induce LTP, predict whether successful LTP will occur. Here, we explored if intra-cerebral treatment with Aβ(1–42), that prevents LTP, also results in alterations of hippocampal oscillations that occur during HFS of the perforant path-dentate gyrus synapse in 6-month-old behaving rats. HFS resulted in LTP that lasted for over 24 h. In Aβ-treated animals, LTP was significantly prevented. During HFS, spectral power for oscillations below 100 Hz (δ, θ, α, β and γ) was significantly higher in Aβ-treated animals compared to controls. In addition, the trough-to-peak amplitudes of theta and gamma cycles were higher during HFS in Aβ-treated animals. We also observed a lower amount of envelope-to-signal correlations during HFS in Aβ-treated animals. Overall, the characteristic profile of theta-gamma oscillations that accompany successful LTP induction was disrupted. These data indicate that alterations in network oscillations accompany Aβ-effects on hippocampal LTP. This may comprise an underlying mechanism through which disturbances in synaptic information storage and hippocampus-dependent memory occurs in AD. PMID:25999827

  7. Electrophysiological correlates of sleep homeostasis in freely behaving rats

    PubMed Central

    Vyazovskiy, Vladyslav V.; Cirelli, Chiara; Tononi, Giulio

    2011-01-01

    The electrical activity of the brain does not only reflect the current level of arousal, ongoing behavior or involvement in a specific task, but is also influenced by what kind of activity, and how much sleep and waking occurred before. The best marker of sleep-wake history is the electroencephalogram (EEG) spectral power in slow frequencies (slow-wave activity, 0.5–4 Hz, SWA) during sleep, which is high after extended wakefulness and low after consolidated sleep. While sleep homeostasis has been well characterized in various species and experimental paradigms, the specific mechanisms underlying homeostatic changes in brain activity or their functional significance remain poorly understood. However, several recent studies in humans, rats and computer simulations shed light on the cortical mechanisms underlying sleep regulation. First, it was found that the homeostatic changes in SWA can be fully accounted for by the variations in amplitude and slope of EEG slow waves, which are in turn determined by the efficacy of cortico-cortical connectivity. Specifically, the slopes of sleep slow waves were steeper in early sleep compared to late sleep. Second, the slope of cortical evoked potentials, which is an established marker of synaptic strength, was steeper after waking and decreased after sleep. Furthermore, cortical long-term potentiation (LTP) was partially occluded if it was induced after a period of waking, but it could again be fully expressed after sleep. Finally, multiunit activity recordings during sleep revealed that cortical neurons fired more synchronously after waking, and less so after a period of consolidated sleep. The decline of all these electrophysiological measures - the slopes of slow waves and evoked potentials and neuronal synchrony – during sleep correlated with the decline of the traditional marker of sleep homeostasis, EEG SWA. Taken together, these data suggest that homeostatic changes in sleep EEG are the result of altered neuronal firing and synchrony, which in turn arise from changes in functional neuronal connectivity. PMID:21854953

  8. Chronic detachable headphones for acoustic stimulation in freely moving animals.

    PubMed

    Nodal, Fernando R; Keating, Peter; King, Andrew J

    2010-05-30

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets' performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals.

  9. Chronic detachable headphones for acoustic stimulation in freely moving animals

    PubMed Central

    Nodal, Fernando R.; Keating, Peter; King, Andrew J.

    2010-01-01

    A growing number of studies of auditory processing are being carried out in awake, behaving animals, creating a need for precisely controlled sound delivery without restricting head movements. We have designed a system for closed-field stimulus presentation in freely moving ferrets, which comprises lightweight, adjustable headphones that can be consistently positioned over the ears via a small, skull-mounted implant. The invasiveness of the implant was minimized by simplifying its construction and using dental adhesive only for attaching it to the skull, thereby reducing the surgery required and avoiding the use of screws or other anchoring devices. Attaching the headphones to a chronic implant also reduced the amount of contact they had with the head and ears, increasing the willingness of the animals to wear them. We validated sound stimulation via the headphones in ferrets trained previously in a free-field task to localize stimuli presented from one of two loudspeakers. Noise bursts were delivered binaurally over the headphones and interaural level differences (ILDs) were introduced to allow the sound to be lateralized. Animals rapidly transferred from the free-field task to indicate the perceived location of the stimulus presented over headphones. They showed near perfect lateralization with a 5 dB ILD, matching the scores achieved in the free-field task. As expected, the ferrets’ performance declined when the ILD was reduced in value. This closed-field system can easily be adapted for use in other species, and provides a reliable means of presenting closed-field stimuli whilst monitoring behavioral responses in freely moving animals. PMID:20346981

  10. Coding odor identity and odor value in awake rodents.

    PubMed

    Nunez-Parra, Alexia; Li, Anan; Restrepo, Diego

    2014-01-01

    In the last decade, drastic changes in the understanding of the role of the olfactory bulb and piriform cortex in odor detection have taken place through awake behaving recording in rodents. It is clear that odor responses in mitral and granule cells are strikingly different in the olfactory bulb of anesthetized versus awake animals. In addition, sniff recording has evidenced that mitral cell responses to odors during the sniff can convey information on the odor identity and sniff phase. Moreover, we review studies that show that the mitral cell conveys information on not only odor identity but also whether the odor is rewarded or not (odor value). Finally, we discuss how the substantial increase in awake behaving recording raises questions for future studies.

  11. A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents

    NASA Astrophysics Data System (ADS)

    Insanally, Michele; Trumpis, Michael; Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

    2016-04-01

    Objective. Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. Approach. Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. Main results. We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ∼10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance. This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision

  12. A low-cost, multiplexed μECoG system for high-density recordings in freely-moving rodents

    PubMed Central

    Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

    2016-01-01

    Objective Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely-behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely-moving rats. Approach Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely-moving awake animals. Main results We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ~10 seconds by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in

  13. Awake right hemisphere brain surgery.

    PubMed

    Hulou, M Maher; Cote, David J; Olubiyi, Olutayo I; Smith, Timothy R; Chiocca, E Antonio; Johnson, Mark D

    2015-12-01

    We report the indications and outcomes of awake right hemispheric brain surgery, as well as a rare patient with crossed aphasia. Awake craniotomies are often performed to protect eloquent cortex. We reviewed the medical records for 35 of 96 patients, in detail, who had awake right hemisphere brain operations. Intraoperative cortical mapping of motor and/or language function was performed in 29 of the 35 patients. A preoperative speech impairment and left hand dominance were the main indicators for awake right-sided craniotomies in patients with right hemisphere lesions. Four patients with lesion proximity to eloquent areas underwent awake craniotomies without cortical mapping. In addition, one patient had a broncho-pulmonary fistula, and another had a recent major cardiac procedure that precluded awake surgery. An eloquent cortex representation was identified in 14 patients (48.3%). Postoperatively, seven of 17 patients (41.1%) who presented with weakness, experienced improvements in their motor functions, 11 of 16 (68.7%) with seizures became seizure-free, and seven of nine (77.7%) with moderate to severe headaches and one of two with a visual field deficit improved significantly. There were also improvements in speech and language functions in all patients who presented with speech difficulties. A right sided awake craniotomy is an excellent option for left handed patients, or those with right sided cortical lesions that result in preoperative speech impairments. When combined with intraoperative cortical mapping, both speech and motor function can be well preserved.

  14. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments. PMID:24692347

  15. Freely floating smectic films.

    PubMed

    May, Kathrin; Harth, Kirsten; Trittel, Torsten; Stannarius, Ralf

    2014-05-19

    We have investigated the dynamics of freely floating smectic bubbles using high-speed optical imaging. Bubbles in the size range from a few hundred micrometers to several centimeters were prepared from collapsing catenoids. They represent ideal model systems for the study of thin-film fluid dynamics under well-controlled conditions. Owing to the internal smectic layer structure, the bubbles combine features of both soap films and vesicles in their unique shape dynamics. From a strongly elongated initial shape after pinch-off, they relax towards the spherical equilibrium, first by a slow redistribution of the smectic layers, and finally by weak, damped shape oscillations. In addition, we describe the rupture of freely floating smectic bubbles, and the formation and stability of smectic filaments.

  16. Real-time dopamine measurement in awake monkeys.

    PubMed

    Schluter, Erik W; Mitz, Andrew R; Cheer, Joseph F; Averbeck, Bruno B

    2014-01-01

    Fast-scan cyclic voltammetry (FSCV) is often used to measure real-time dopamine (DA) concentrations in awake, behaving rodents. Extending this technique to work in monkeys would provide a platform for advanced behavioral studies and a primate model for preclinical research. The present study demonstrates the feasibility of DA recordings in two awake monkeys (Macaca mulatta) using a mixture of techniques adapted from rodent, primate and brain slice work. We developed a long carbon fiber electrode to operate in the larger primate brain. This electrode was lowered into the striatum each day using a recording chamber and a detachable micromanipulator system. A manipulator also moved one or more tungsten stimulating electrodes into either the nearby striatum or the ventral tegmental area/substantia nigra pars compacta (VTA/SNc). We developed an electrical stimulation controller to reduce artifacts during electrical stimulation. We also introduce a stimulation-based methodology for estimating distances between electrodes in the brain. Dopamine responses within the striatum were evoked by either stimulation of the striatum near the FSCV electrode, or stimulation within the VTA/SNc. Unexpected juice rewards also evoked dopamine responses in the ventral striatum. Thus, we demonstrate that robust dopamine responses can be recorded from awake, behaving primates with FSCV. In addition, we describe how a stimulation technique borrowed from the neuroprosthetics field can activate the distributed monkey midbrain dopamine system in a way that mimics rodent VTA stimulation. PMID:24921937

  17. Real-Time Dopamine Measurement in Awake Monkeys

    PubMed Central

    Schluter, Erik W.; Mitz, Andrew R.; Cheer, Joseph F.; Averbeck, Bruno B.

    2014-01-01

    Fast-scan cyclic voltammetry (FSCV) is often used to measure real-time dopamine (DA) concentrations in awake, behaving rodents. Extending this technique to work in monkeys would provide a platform for advanced behavioral studies and a primate model for preclinical research. The present study demonstrates the feasibility of DA recordings in two awake monkeys (Macaca mulatta) using a mixture of techniques adapted from rodent, primate and brain slice work. We developed a long carbon fiber electrode to operate in the larger primate brain. This electrode was lowered into the striatum each day using a recording chamber and a detachable micromanipulator system. A manipulator also moved one or more tungsten stimulating electrodes into either the nearby striatum or the ventral tegmental area/substantia nigra pars compacta (VTA/SNc). We developed an electrical stimulation controller to reduce artifacts during electrical stimulation. We also introduce a stimulation-based methodology for estimating distances between electrodes in the brain. Dopamine responses within the striatum were evoked by either stimulation of the striatum near the FSCV electrode, or stimulation within the VTA/SNc. Unexpected juice rewards also evoked dopamine responses in the ventral striatum. Thus, we demonstrate that robust dopamine responses can be recorded from awake, behaving primates with FSCV. In addition, we describe how a stimulation technique borrowed from the neuroprosthetics field can activate the distributed monkey midbrain dopamine system in a way that mimics rodent VTA stimulation. PMID:24921937

  18. Long-term imaging in awake mice using removable cranial windows

    PubMed Central

    Glickfeld, Lindsey L.; Kerlin, Aaron M.; Reid, R. Clay; Bonin, Vincent; Schafer, Dorothy P.; Andermann, Mark L.

    2015-01-01

    Cranial window implants in head-fixed rodents are becoming a preparation of choice for stable optical access to large areas of cortex over extended periods of time. Here, we provide a highly detailed and reliable surgical protocol for a cranial window implantation procedure for chronic widefield and cellular imaging in awake, head-fixed mice, which enables subsequent window removal and replacement in the weeks and months following the initial craniotomy. This protocol has facilitated awake, chronic imaging in adolescent as well as adult mice over several months from a large number of cortical brain regions; targeted virus and tracer injections from data obtained using prior awake functional mapping; and functionally-targeted two-photon imaging across all cortical layers in awake mice using a microprism attachment to the cranial window. Collectively, these procedures extend the reach of chronic imaging of cortical function and dysfunction in behaving animals. PMID:25275789

  19. Visually evoked activity in cortical cells imaged in freely moving animals

    PubMed Central

    Sawinski, Juergen; Wallace, Damian J.; Greenberg, David S.; Grossmann, Silvie; Denk, Winfried; Kerr, Jason N. D.

    2009-01-01

    We describe a miniaturized head-mounted multiphoton microscope and its use for recording Ca2+ transients from the somata of layer 2/3 neurons in the visual cortex of awake, freely moving rats. Images contained up to 20 neurons and were stable enough to record continuously for >5 min per trial and 20 trials per imaging session, even as the animal was running at velocities of up to 0.6 m/s. Neuronal Ca2+ transients were readily detected, and responses to various static visual stimuli were observed during free movement on a running track. Neuronal activity was sparse and increased when the animal swept its gaze across a visual stimulus. Neurons showing preferential activation by specific stimuli were observed in freely moving animals. These results demonstrate that the multiphoton fiberscope is suitable for functional imaging in awake and freely moving animals. PMID:19889973

  20. Swept confocally-aligned planar excitation (SCAPE) microscopy for high-speed volumetric imaging of behaving organisms

    NASA Astrophysics Data System (ADS)

    Bouchard, Matthew B.; Voleti, Venkatakaushik; Mendes, César S.; Lacefield, Clay; Grueber, Wesley B.; Mann, Richard S.; Bruno, Randy M.; Hillman, Elizabeth M. C.

    2015-02-01

    We report a three-dimensional microscopy technique—swept, confocally-aligned planar excitation (SCAPE) microscopy—that allows volumetric imaging of living samples at ultrahigh speeds. Although confocal and two-photon microscopy have revolutionized biomedical research, current implementations are costly, complex and limited in their ability to image three-dimensional volumes at high speeds. Light-sheet microscopy techniques using two-objective, orthogonal illumination and detection require a highly constrained sample geometry and either physical sample translation or complex synchronization of illumination and detection planes. In contrast, SCAPE microscopy acquires images using an angled, swept light sheet in a single-objective, en face geometry. Unique confocal descanning and image rotation optics map this moving plane onto a stationary high-speed camera, permitting completely translationless three-dimensional imaging of intact samples at rates exceeding 20 volumes per second. We demonstrate SCAPE microscopy by imaging spontaneous neuronal firing in the intact brain of awake behaving mice, as well as freely moving transgenic Drosophila larvae.

  1. Awake transapical aortic valve implantation.

    PubMed

    Petridis, Francesco Dimitri; Savini, Carlo; Castelli, Andrea; Di Bartolomeo, Roberto

    2012-05-01

    Transapical aortic valve implantation is being employed as a less invasive alternative to open heart surgery in high-risk patients with severe aortic stenosis. Here we report the case of an awake transapical aortic valve implantation in a patient with severe chronic obstructive pulmonary disease.

  2. Optical methods and integrated systems for brain imaging in awake, untethered animals

    NASA Astrophysics Data System (ADS)

    Murari, Kartikeya

    Imaging is a powerful tool for biomedical research offering non-contact and minimally or non-invasive means of investigating at multiple scales---from single molecules to large populations of cells. Imaging in awake, behaving animals is an emerging field that offers the additional advantage of being able to study physiological processes and structures in a more natural state than what is possible in tissue slices or even in anesthetized animals. To date, most imaging in awake animals has used optical fiber bundles or electrical cables to transfer signals to traditional imaging-system components. However, the fibers or cables tether the animal and greatly limit the kind and duration of animal behavior that can be studied using imaging methods. This work involves three distinct yet related approaches to fulfill the goal of imaging in unanesthetized, unrestrained animals---optical techniques for functional and structural imaging, development of novel photodetectors and the design of miniaturized imaging systems. I hypothesized that the flow within vessels might act as a contrast-enhancing agent and improve the visualization of vascular architecture using laser speckle imaging. When imaging rodent cerebral vasculature I saw a two to four fold increase in the contrast-to-noise ratios and was able to visualize 10--30% more vascular features over reflectance techniques. I designed a complementary metal oxide semiconductor (CMOS) photodetector array that was comparable in sensitivity and noise performance to cooled CCD sensors, able to image fluorescence from a single cell, while running at faster frame rates. Next, I designed an imaging system weighing under 6 grams and occupying less than 4 cm3. The system incorporated multispectral illumination, adjustable focusing optics and the high-sensitivity CMOS imager. I was able to implement a variety of optical modalities with the system and performed reflectance, fluorescence, spectroscopic and laser speckle imaging with my

  3. Effects of a ketogenic diet on hippocampal plasticity in freely moving juvenile rats

    PubMed Central

    Blaise, J Harry; Ruskin, David N; Koranda, Jessica L; Masino, Susan A

    2015-01-01

    Ketogenic diets are low-carbohydrate, sufficient protein, high-fat diets with anticonvulsant activity used primarily as a treatment for pediatric epilepsy. The anticonvulsant mechanism is thought to involve elevating inhibition and/or otherwise limiting excitability in the brain. Such a mechanism, however, might also significantly affect normal brain activity and limit synaptic plasticity, effects that would be important to consider in the developing brain. To assess ketogenic diet effects on synaptic transmission and plasticity, electrophysiological recordings were performed at the perforant path/dentate gyrus synapse in awake, freely-behaving juvenile male rats. Electrodes were implanted 1 week prior to recording. Animals were fed regular chow or a ketogenic diet ad libitum for 3 weeks before recording. Although the ketogenic diet did not significantly alter baseline excitability (assessed by input–output curves) or short-term plasticity (using the paired-pulse ratio), it did reduce the magnitude of long-term potentiation at all poststimulation timepoints out to the last time measured (48 h). The results suggest an effect of ketogenic diet-feeding on the induction magnitude but not the maintenance of long-term potentiation. The lack of effect of the diet on baseline transmission and the paired-pulse ratio suggests a mechanism that limits excitation preferentially in conditions of strong stimulation, consonant with clinical reports in which the ketogenic diet alleviates seizures without a major impact on normal brain activity. Limiting plasticity in a seizure-susceptible network may limit seizure-induced epileptogenesis which may subserve the ongoing benefit of the ketogenic diet in epilepsy. PMID:26009636

  4. GABAB receptor blockade enhances theta and gamma rhythms in the hippocampus of behaving rats.

    PubMed

    Leung, L Stan; Shen, Bixia

    2007-01-01

    The participation of GABA(B) receptors in hippocampal EEG generation was studied by intracerebroventricular (icv) and intracerebral infusions of GABA(B) receptor antagonist p-(3-aminopropyl)-p-diethoxymethyl-phosphinic acid (CGP35348) in freely behaving rats. During awake-immobility, icv CGP35348 induced a theta rhythm and increased gamma waves (30-100 Hz) in the hippocampus. The immobility theta peaked at 6-7 Hz and had a theta phase in CA1 stratum radiatum of approximately 160 degrees with reference to the theta at the alveus, when compared with approximately 130 degrees during walking. Immobility theta power peaks at 6-7 Hz was also found in normal rats, and it was detected in 27% of the EEG segments during immobility. Incidence of immobility theta increased to 87.5% after 480 nmol of CGP35348 icv. Muscarinic antagonist scopolamine (5 mg/kg, ip) suppressed the induction of immobility theta and the gamma power increase after icv CGP35348. CGP35348 icv did not significantly change the hippocampal theta power at 7-8 Hz during walking (theta fundamental), but it increased power at 12-15 Hz, at the second harmonic of theta. CGP35348 icv also increased 30-50 Hz gamma power during walking. Medial septal infusion of CGP35348 (12 nmol in 0.4 microl) increased the power and the frequency of the hippocampal theta second harmonic during walking, but did not increase gamma activity. Infusion of CGP35348 (8 nmol in 0.4 microl) in the hippocampus increased the local gamma activity at 30-100 Hz, but did not induce immobility theta or affect the walking theta rhythm. In conclusion, icv GABA(B) receptor blockade increased an atropine-sensitive input that generated an immobility theta rhythm, while GABA(B) receptor blockade of the medial septum increased atropine-resistant theta harmonics possibly generated by apical dendritic spikes. GABA(B) receptor blockade may enhance cognitive task performance by activating hippocampal theta and gamma rhythms in behaving rats.

  5. Awake operative videothoracoscopic pulmonary resections.

    PubMed

    Pompeo, Eugenio; Mineo, Tommaso C

    2008-08-01

    The authors' initial experience with awake videothoracoscopic lung resection suggests that these procedures can be easily and safely performed under sole thoracic epidural anesthesia with no mortality and negligible morbidity. One major concern was that operating on a ventilating lung would render surgical maneuvers more difficult because of the lung movements and lack of a sufficient operating space. Instead, the open pneumothorax created after trocar insertion produces a satisfactory lung collapse that does not hamper surgical maneuvers. These results contradict the accepted assumption that the main prerequisite for allowing successful thoracoscopic lung surgery is general anesthesia with one-lung ventilation. No particular training is necessary to accomplish an awake pulmonary resection for teams experienced in thoracoscopic surgery, and conversions to general anesthesia are mainly caused by the presence of extensive fibrous pleural adhesions or the development of intractable panic attacks. Overall, awake pulmonary resection is easily accepted and well tolerated by patients, as confirmed by the high anesthesia satisfaction score, which was better than in nonawake control patients. Nonetheless, thoracic epidural anesthesia has potential complications, including epidural hematoma, spinal cord injury, and phrenic nerve palsy caused by inadvertently high anesthetic level, but these never occurred in the authors' experience. Further concerns relate to patient participation in operating room conversations or risk for development of perioperative panic attacks. However, the authors have found that reassuring the patient during the procedure, explaining step-by-step what is being performed, and even showing the ongoing procedure on the operating video can greatly improve the perioperative wellness and expectations of patients, particularly if the procedure is performed for oncologic diseases. Panic attacks occurred in few patients and could be usually managed through

  6. Extracellular Wire Tetrode Recording in Brain of Freely Walking Insects

    PubMed Central

    Guo, Peiyuan; Pollack, Alan J.; Varga, Adrienn G.; Martin, Joshua P.; Ritzmann, Roy E.

    2014-01-01

    Increasing interest in the role of brain activity in insect motor control requires that we be able to monitor neural activity while insects perform natural behavior. We previously developed a technique for implanting tetrode wires into the central complex of cockroach brains that allowed us to record activity from multiple neurons simultaneously while a tethered cockroach turned or altered walking speed. While a major advance, tethered preparations provide access to limited behaviors and often lack feedback processes that occur in freely moving animals. We now present a modified version of that technique that allows us to record from the central complex of freely moving cockroaches as they walk in an arena and deal with barriers by turning, climbing or tunneling. Coupled with high speed video and cluster cutting, we can now relate brain activity to various parameters of the movement of freely behaving insects. PMID:24747699

  7. Sweet and bitter taste in the brain of awake behaving animals.

    PubMed

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J P; Zuker, Charles S

    2015-11-26

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviours, preventing the ingestion of toxic substances, and helping to ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste allows the identification of energy-rich nutrients whereas bitter warns against the intake of potentially noxious chemicals. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map, with each taste quality encoded by distinct cortical fields. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal's internal representation, sensory perception, and behavioural actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviours in the absence of sensory input.

  8. Oscillations in the premotor cortex: single-unit activity from awake, behaving monkeys.

    PubMed

    Lebedev, M A; Wise, S P

    2000-01-01

    We examined single-unit activity in the dorsal premotor cortex for evidence of fast neuronal oscillations. Four rhesus monkeys performed a task in which visuospatial instruction stimuli indicated the direction of forelimb movement to be executed on each trial. After an instructed delay period of 1.5-3 s, movements to either the right or left of a central origin were triggered by a second visuospatial stimulus. From a database of 579 single units, 78 units (13%) contained periodic peaks in their autocorrelation histograms (ACHs), with oscillation frequencies typically 20-30 Hz (mean 27 Hz). An additional 26 units (5%) had oscillatory features that were identified in joint interspike-interval (ISI) plots. Three observations, taken together, suggest entrainment by rhythmic drive extrinsic to these neurons: shuffling ISIs attenuated ACH peaks, indicating a dependency on serial-order effects; oscillation frequency did not change during either increases or decreases in firing rate; and joint ISI plots contained features consistent with a rhythmicity interrupted by intervening discharges. In some cells, oscillations occurred for only one of the two directions of movement. During the delay period, such directional selectivity was observed in 37 units (60% of delay-period oscillators). For at least 17 of these units, we could exclude the possibility that oscillatory directional selectivity resulted from the difficulty in detecting oscillations due to low discharge rates (for one of the two movement directions). Directional selectivity in fast oscillations shows that they can reflect specific aspects of an intended action. PMID:10672473

  9. Stimulation of the nucleus accumbens as behavioral reward in awake behaving monkeys.

    PubMed

    Bichot, Narcisse P; Heard, Matthew T; Desimone, Robert

    2011-08-15

    It has been known that monkeys will repeatedly press a bar for electrical stimulation in several different brain structures. We explored the possibility of using electrical stimulation in one such structure, the nucleus accumbens, as a substitute for liquid reward in animals performing a complex task, namely visual search. The animals had full access to water in the cage at all times on days when stimulation was used to motivate them. Electrical stimulation was delivered bilaterally at mirror locations in and around the accumbens, and the animals' motivation to work for electrical stimulation was quantified by the number of trials they performed correctly per unit of time. Acute mapping revealed that stimulation over a large area successfully supported behavioral performance during the task. Performance improved with increasing currents until it reached an asymptotic, theoretically maximal level. Moreover, stimulation with chronically implanted electrodes showed that an animal's motivation to work for electrical stimulation was at least equivalent to, and often better than, when it worked for liquid reward while on water control. These results suggest that electrical stimulation in the accumbens is a viable method of reward in complex tasks. Because this method of reward does not necessitate control over water or food intake, it may offer an alternative to the traditional liquid or food rewards in monkeys, depending on the goals and requirements of the particular research project. PMID:21704383

  10. Stimulation of the nucleus accumbens as behavioral reward in awake behaving monkeys.

    PubMed

    Bichot, Narcisse P; Heard, Matthew T; Desimone, Robert

    2011-08-15

    It has been known that monkeys will repeatedly press a bar for electrical stimulation in several different brain structures. We explored the possibility of using electrical stimulation in one such structure, the nucleus accumbens, as a substitute for liquid reward in animals performing a complex task, namely visual search. The animals had full access to water in the cage at all times on days when stimulation was used to motivate them. Electrical stimulation was delivered bilaterally at mirror locations in and around the accumbens, and the animals' motivation to work for electrical stimulation was quantified by the number of trials they performed correctly per unit of time. Acute mapping revealed that stimulation over a large area successfully supported behavioral performance during the task. Performance improved with increasing currents until it reached an asymptotic, theoretically maximal level. Moreover, stimulation with chronically implanted electrodes showed that an animal's motivation to work for electrical stimulation was at least equivalent to, and often better than, when it worked for liquid reward while on water control. These results suggest that electrical stimulation in the accumbens is a viable method of reward in complex tasks. Because this method of reward does not necessitate control over water or food intake, it may offer an alternative to the traditional liquid or food rewards in monkeys, depending on the goals and requirements of the particular research project.

  11. Sweet and bitter taste in the brain of awake behaving animals

    PubMed Central

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J. P.; Zuker, Charles S.

    2015-01-01

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviors, preventing the ingestion of toxic substances, and helping ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste permits the identification of energy-rich nutrients while bitter warns against the intake of potentially noxious chemicals1. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain2. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map3,4, with each taste quality encoded by distinct cortical fields4. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal’s internal representation, sensory perception, and behavioral actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviors in the absence of sensory input. PMID:26580015

  12. Sweet and bitter taste in the brain of awake behaving animals.

    PubMed

    Peng, Yueqing; Gillis-Smith, Sarah; Jin, Hao; Tränkner, Dimitri; Ryba, Nicholas J P; Zuker, Charles S

    2015-11-26

    Taste is responsible for evaluating the nutritious content of food, guiding essential appetitive behaviours, preventing the ingestion of toxic substances, and helping to ensure the maintenance of a healthy diet. Sweet and bitter are two of the most salient sensory percepts for humans and other animals; sweet taste allows the identification of energy-rich nutrients whereas bitter warns against the intake of potentially noxious chemicals. In mammals, information from taste receptor cells in the tongue is transmitted through multiple neural stations to the primary gustatory cortex in the brain. Recent imaging studies have shown that sweet and bitter are represented in the primary gustatory cortex by neurons organized in a spatial map, with each taste quality encoded by distinct cortical fields. Here we demonstrate that by manipulating the brain fields representing sweet and bitter taste we directly control an animal's internal representation, sensory perception, and behavioural actions. These results substantiate the segregation of taste qualities in the cortex, expose the innate nature of appetitive and aversive taste responses, and illustrate the ability of gustatory cortex to recapitulate complex behaviours in the absence of sensory input. PMID:26580015

  13. Are Girls Behaving like Boys?

    ERIC Educational Resources Information Center

    Arnott, Rosie

    2008-01-01

    This article explores some of the issues that have given rise to the perception of an increase in aggressive behaviour by females. It asserts that merely comparing girls' behaviour with that of boys, especially the claim that "girls are behaving like boys", trivialises the very real issues associated with females and aggression. This paper will…

  14. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure.

    PubMed

    Claussen, Catherine M; Dafny, Nachum

    2015-09-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long-term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization was also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals were observed for the 2.5 and 10.0mg/kg MPD exposed groups. For 2.5mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0mg/kg MPD and the behaviorally sensitized 10.0mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and then to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure.

  15. Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure

    PubMed Central

    Claussen, Catherine M; Dafny, Nachum

    2016-01-01

    The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0 mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization were also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals was observed for the 2.5 and 10.0 mg/kg MPD exposed groups. For 2.5 mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0 mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0 mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0 mg/kg MPD and the behaviorally sensitized 10.0 mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and than to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure. PMID:26101057

  16. Freely oriented portable superconducting magnet

    SciTech Connect

    Schmierer, Eric N.; Prenger, F. Coyne; Hill, Dallas D.

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  17. Noninvasive high-speed photoacoustic tomography of cerebral hemodynamics in awake-moving rats

    PubMed Central

    Tang, Jianbo; Xi, Lei; Zhou, Junli; Huang, Hua; Zhang, Tao; Carney, Paul R; Jiang, Huabei

    2015-01-01

    We present a noninvasive method of photoacoustic tomography (PAT) for imaging cerebral hemodynamics in awake-moving rats. The wearable PAT (wPAT) system has a size of 15 mm in height and 33 mm in diameter, and a weight of ~8 g (excluding cabling). The wPAT achieved an imaging rate of 3.33 frames/s with a lateral resolution of 243 μm. Animal experiments were designed to show wPAT feasibility for imaging cerebral hemodynamics on awake-moving animals. Results showed that the cerebral oxy-hemoglobin and deoxy-hemoglobin changed significantly in response to hyperoxia; and, after the injection of pentylenetetrazol (PTZ), cerebral blood volume changed faster over time and larger in amplitude for rats in awake-moving state compared with rats under anesthesia. By providing a light-weight, high-resolution technology for in vivo monitoring of cerebral hemodynamics in awake-behaving animals, it will be possible to develop a comprehensive understanding on how activity alters hemodynamics in normal and diseased states. PMID:26082016

  18. Evaluation of Language Function under Awake Craniotomy

    PubMed Central

    KANNO, Aya; MIKUNI, Nobuhiro

    2015-01-01

    Awake craniotomy is the only established way to assess patients’ language functions intraoperatively and to contribute to their preservation, if necessary. Recent guidelines have enabled the approach to be used widely, effectively, and safely. Non-invasive brain functional imaging techniques, including functional magnetic resonance imaging and diffusion tensor imaging, have been used preoperatively to identify brain functional regions corresponding to language, and their accuracy has increased year by year. In addition, the use of neuronavigation that incorporates this preoperative information has made it possible to identify the positional relationships between the lesion and functional regions involved in language, conduct functional brain mapping in the awake state with electrical stimulation, and intraoperatively assess nerve function in real time when resecting the lesion. This article outlines the history of awake craniotomy, the current state of pre- and intraoperative evaluation of language function, and the clinical usefulness of such functional evaluation. When evaluating patients’ language functions during awake craniotomy, given the various intraoperative stresses involved, it is necessary to carefully select the tasks to be undertaken, quickly perform all examinations, and promptly evaluate the results. As language functions involve both input and output, they are strongly affected by patients’ preoperative cognitive function, degree of intraoperative wakefulness and fatigue, the ability to produce verbal articulations and utterances, as well as perform synergic movement. Therefore, it is essential to appropriately assess the reproducibility of language function evaluation using awake craniotomy techniques. PMID:25925758

  19. Awake Craniotomy: A New Airway Approach.

    PubMed

    Sivasankar, Chitra; Schlichter, Rolf A; Baranov, Dimitry; Kofke, W Andrew

    2016-02-01

    Awake craniotomies have been performed regularly at the University of Pennsylvania since 2004. Varying approaches to airway management are described for this procedure, including intubation with an endotracheal tube and use of a laryngeal mask airway, simple facemask, or nasal cannula. In this case series, we describe the successful use (i.e., no need for endotracheal intubation related to inadequate gas exchange) of bilateral nasopharyngeal airways in 90 patients undergoing awake craniotomies. The use of nasopharyngeal airways can ease the transition between the asleep and awake phases of the craniotomy without the need to stimulate the airway. Our purpose was to describe our experience and report adverse events related to this technique. PMID:26579845

  20. Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit.

    PubMed

    Kenkel, W M; Yee, J R; Moore, K; Madularu, D; Kulkarni, P; Gamber, K; Nedelman, M; Ferris, C F

    2016-01-01

    Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were 'odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology. PMID:27003189

  1. Functional magnetic resonance imaging in awake transgenic fragile X rats: evidence of dysregulation in reward processing in the mesolimbic/habenular neural circuit

    PubMed Central

    Kenkel, W M; Yee, J R; Moore, K; Madularu, D; Kulkarni, P; Gamber, K; Nedelman, M; Ferris, C F

    2016-01-01

    Anxiety and social deficits, often involving communication impairment, are fundamental clinical features of fragile X syndrome. There is growing evidence that dysregulation in reward processing is a contributing factor to the social deficits observed in many psychiatric disorders. Hence, we hypothesized that transgenic fragile X mental retardation 1 gene (fmr1) KO (FX) rats would display alterations in reward processing. To this end, awake control and FX rats were imaged for changes in blood oxygen level dependent (BOLD) signal intensity in response to the odor of almond, a stimulus to elicit the innate reward response. Subjects were ‘odor naive' to this evolutionarily conserved stimulus. The resulting changes in brain activity were registered to a three-dimensional segmented, annotated rat atlas delineating 171 brain regions. Both wild-type (WT) and FX rats showed robust brain activation to a rewarding almond odor, though FX rats showed an altered temporal pattern and tended to have a higher number of voxels with negative BOLD signal change from baseline. This pattern of greater negative BOLD was especially apparent in the Papez circuit, critical to emotional processing and the mesolimbic/habenular reward circuit. WT rats showed greater positive BOLD response in the supramammillary area, whereas FX rats showed greater positive BOLD response in the dorsal lateral striatum, and greater negative BOLD response in the retrosplenial cortices, the core of the accumbens and the lateral preoptic area. When tested in a freely behaving odor-investigation paradigm, FX rats failed to show the preference for almond odor which typifies WT rats. However, FX rats showed investigation profiles similar to WT when presented with social odors. These data speak to an altered processing of this highly salient novel odor in the FX phenotype and lend further support to the notion that altered reward systems in the brain may contribute to fragile X syndrome symptomology. PMID:27003189

  2. Path to AWAKE: Evolution of the concept

    DOE PAGESBeta

    Caldwell, A.; Adli, E.; Amorim, L.; Apsimon, R.; Argyropoulos, T.; Assmann, R.; Bachmann, A. -M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; et al

    2016-01-02

    This study describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability – a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of themore » AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1] .« less

  3. Path to AWAKE: Evolution of the concept

    NASA Astrophysics Data System (ADS)

    Caldwell, A.; Adli, E.; Amorim, L.; Apsimon, R.; Argyropoulos, T.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Cascella, M.; Chattopadhyay, S.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Elsen, E.; Farmer, J.; Fartoukh, S.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Geschonke, G.; Goddard, B.; Gorn, A. A.; Grulke, O.; Gschwendtner, E.; Hansen, J.; Hessler, C.; Hillenbrand, S.; Hofle, W.; Holloway, J.; Huang, C.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Kersevan, R.; Kumar, N.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Lu, W.; Machacek, J.; Mandry, S.; Martin, I.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Meddahi, M.; Merminga, L.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Müller, A.-S.; Najmudin, Z.; Noakes, T. C. Q.; Norreys, P.; Osterhoff, J.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pozimski, J.; Pukhov, A.; Reimann, O.; Rieger, K.; Roesler, S.; Ruhl, H.; Rusnak, T.; Salveter, F.; Savard, N.; Schmidt, J.; von der Schmitt, H.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Simon, F.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Tajima, T.; Tarkeshian, R.; Timko, H.; Trines, R.; Tückmantel, T.; Tuev, P. V.; Turner, M.; Velotti, F.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Yakimenko, V.; Zhang, H.; Zimmermann, F.

    2016-09-01

    This paper describes the conceptual steps in reaching the design of the AWAKE experiment currently under construction at CERN. We start with an introduction to plasma wakefield acceleration and the motivation for using proton drivers. We then describe the self-modulation instability - a key to an early realization of the concept. This is then followed by the historical development of the experimental design, where the critical issues that arose and their solutions are described. We conclude with the design of the experiment as it is being realized at CERN and some words on the future outlook. A summary of the AWAKE design and construction status as presented in this conference is given in Gschwendtner et al. [1].

  4. Awake, Offline Processing during Associative Learning

    PubMed Central

    Nestor, Adrian; Tarr, Michael J.; Creswell, J. David

    2016-01-01

    Offline processing has been shown to strengthen memory traces and enhance learning in the absence of conscious rehearsal or awareness. Here we evaluate whether a brief, two-minute offline processing period can boost associative learning and test a memory reactivation account for these offline processing effects. After encoding paired associates, subjects either completed a distractor task for two minutes or were immediately tested for memory of the pairs in a counterbalanced, within-subjects functional magnetic resonance imaging study. Results showed that brief, awake, offline processing improves memory for associate pairs. Moreover, multi-voxel pattern analysis of the neuroimaging data suggested reactivation of encoded memory representations in dorsolateral prefrontal cortex during offline processing. These results signify the first demonstration of awake, active, offline enhancement of associative memory and suggest that such enhancement is accompanied by the offline reactivation of encoded memory representations. PMID:27119345

  5. Human Cortical Excitability Increases with Time Awake

    PubMed Central

    Huber, Reto; Mäki, Hanna; Rosanova, Mario; Casarotto, Silvia; Canali, Paola; Casali, Adenauer G.; Tononi, Giulio

    2013-01-01

    Prolonged wakefulness is associated not only with obvious changes in the way we feel and perform but also with well-known clinical effects, such as increased susceptibility to seizures, to hallucinations, and relief of depressive symptoms. These clinical effects suggest that prolonged wakefulness may be associated with significant changes in the state of cortical circuits. While recent animal experiments have reported a progressive increase of cortical excitability with time awake, no conclusive evidence could be gathered in humans. In this study, we combine transcranial magnetic stimulation (TMS) and electroencephalography (EEG) to monitor cortical excitability in healthy individuals as a function of time awake. We observed that the excitability of the human frontal cortex, measured as the immediate (0–20 ms) EEG reaction to TMS, progressively increases with time awake, from morning to evening and after one night of total sleep deprivation, and that it decreases after recovery sleep. By continuously monitoring vigilance, we also found that this modulation in cortical responsiveness is tonic and not attributable to transient fluctuations of the level of arousal. The present results provide noninvasive electrophysiological evidence that wakefulness is associated with a steady increase in the excitability of human cortical circuits that is rebalanced during sleep. PMID:22314045

  6. A Pressure Injection System for Investigating the Neuropharmacology of Information Processing in Awake Behaving Macaque Monkey Cortex

    PubMed Central

    Veith, Vera K.; Quigley, Cliodhna; Treue, Stefan

    2016-01-01

    The top-down modulation of feed-forward cortical information processing is functionally important for many cognitive processes, including the modulation of sensory information processing by attention. However, little is known about which neurotransmitter systems are involved in such modulations. A practical way to address this question is to combine single-cell recording with local and temporary neuropharmacological manipulation in a suitable animal model. Here we demonstrate a technique combining acute single-cell recordings with the injection of neuropharmacological agents in the direct vicinity of the recording electrode. The video shows the preparation of the pressure injection/recording system, including preparation of the substance to be injected. We show a rhesus monkey performing a visual attention task and the procedure of single-unit recording with block-wise pharmacological manipulations. PMID:27023110

  7. The relationship between gamma frequency and running speed differs for slow and fast gamma rhythms in freely behaving rats.

    PubMed

    Zheng, Chenguang; Bieri, Kevin Wood; Trettel, Sean Gregory; Colgin, Laura Lee

    2015-08-01

    In hippocampal area CA1 of rats, the frequency of gamma activity has been shown to increase with running speed (Ahmed and Mehta, 2012). This finding suggests that different gamma frequencies simply allow for different timings of transitions across cell assemblies at varying running speeds, rather than serving unique functions. However, accumulating evidence supports the conclusion that slow (∼25-55 Hz) and fast (∼60-100 Hz) gamma are distinct network states with different functions. If slow and fast gamma constitute distinct network states, then it is possible that slow and fast gamma frequencies are differentially affected by running speed. In this study, we tested this hypothesis and found that slow and fast gamma frequencies change differently as a function of running speed in hippocampal areas CA1 and CA3, and in the superficial layers of the medial entorhinal cortex (MEC). Fast gamma frequencies increased with increasing running speed in all three areas. Slow gamma frequencies changed significantly less across different speeds. Furthermore, at high running speeds, CA3 firing rates were low, and MEC firing rates were high, suggesting that CA1 transitions from CA3 inputs to MEC inputs as running speed increases. These results support the hypothesis that slow and fast gamma reflect functionally distinct states in the hippocampal network, with fast gamma driven by MEC at high running speeds and slow gamma driven by CA3 at low running speeds.

  8. Awake craniotomy and multilingualism: language testing during anaesthesia for awake craniotomy in a bilingual patient.

    PubMed

    Costello, T G

    2014-08-01

    An awake craniotomy for epilepsy surgery is presented where a bilingual patient post-operatively reported temporary aphasia of his first language (Spanish). This case report discusses the potential causes for this clinical presentation and methods to prevent the occurrence of this in future patients undergoing this form of surgery.

  9. Calcium neuroimaging in behaving zebrafish larvae using a turn-key light field camera

    NASA Astrophysics Data System (ADS)

    Cruz Perez, Carlos; Lauri, Antonella; Symvoulidis, Panagiotis; Cappetta, Michele; Erdmann, Arne; Westmeyer, Gil Gregor

    2015-09-01

    Reconstructing a three-dimensional scene from multiple simultaneously acquired perspectives (the light field) is an elegant scanless imaging concept that can exceed the temporal resolution of currently available scanning-based imaging methods for capturing fast cellular processes. We tested the performance of commercially available light field cameras on a fluorescent microscopy setup for monitoring calcium activity in the brain of awake and behaving reporter zebrafish larvae. The plenoptic imaging system could volumetrically resolve diverse neuronal response profiles throughout the zebrafish brain upon stimulation with an aversive odorant. Behavioral responses of the reporter fish could be captured simultaneously together with depth-resolved neuronal activity. Overall, our assessment showed that with some optimizations for fluorescence microscopy applications, commercial light field cameras have the potential of becoming an attractive alternative to custom-built systems to accelerate molecular imaging research on cellular dynamics.

  10. State of awakeness during visual fixation in preterm infants.

    PubMed

    Hack, M; Muszynski, S Y; Miranda, S B

    1981-07-01

    To demonstrate the presence of discriminable awake states in preterm infants, facial behaviors and visual fixation to a single patterned stimulus were recorded. Five healthy preterm infants born at a mean of 29 weeks' gestation were followed from 30 to 35 weeks' postmenstrual age. Behaviors (eye openness, movements, mouthing, and vocalizations) were recorded simultaneously with visual fixation measured by the corneal reflection technique. Test time was determined by the duration of time the infant remained awake before crying or closing eyes. The presence of both quiet awakeness and drowsiness was demonstrated. Younger infants spent more time in drowsiness, whereas older infants had more quiet awakeness. Visual pattern fixation was observed as early as 30 weeks. Fixation time increased with increasing postmenstrual age. More fixation was observed during quiet awakeness than during drowsiness.

  11. Functional imaging in freely moving animals.

    PubMed

    Kerr, Jason N D; Nimmerjahn, Axel

    2012-02-01

    Uncovering the relationships between animal behavior and cellular activity in the brain has been one of the key aims of neuroscience research for decades, and still remains so. Electrophysiological approaches have enabled sparse sampling from electrically excitable cells in freely moving animals that has led to the identification of important phenomena such as place, grid and head-direction cells. Optical imaging in combination with newly developed labeling approaches now allows minimally invasive and comprehensive sampling from dense networks of electrically and chemically excitable cells such as neurons and glia during self-determined behavior. To achieve this two main imaging avenues have been followed: Optical recordings in head-restrained, mobile animals and miniature microscope-bearing freely moving animals. Here we review progress made toward functional cellular imaging in freely moving rodents, focusing on developments over the past few years. We discuss related challenges and biological applications.

  12. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

    NASA Astrophysics Data System (ADS)

    Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

    2014-08-01

    A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays.

  13. A programmable closed-loop recording and stimulating wireless system for behaving small laboratory animals

    PubMed Central

    Angotzi, Gian Nicola; Boi, Fabio; Zordan, Stefano; Bonfanti, Andrea; Vato, Alessandro

    2014-01-01

    A portable 16-channels microcontroller-based wireless system for a bi-directional interaction with the central nervous system is presented in this work. The device is designed to be used with freely behaving small laboratory animals and allows recording of spontaneous and evoked neural activity wirelessly transmitted and stored on a personal computer. Biphasic current stimuli with programmable duration, frequency and amplitude may be triggered in real-time on the basis of the recorded neural activity as well as by the animal behavior within a specifically designed experimental setup. An intuitive graphical user interface was developed to configure and to monitor the whole system. The system was successfully tested through bench tests and in vivo measurements on behaving rats chronically implanted with multi-channels microwire arrays. PMID:25096831

  14. Astrocyte and microvascular imaging in awake animals using two-photon microscopy.

    PubMed

    Tran, Cam Ha T; Gordon, Grant R

    2015-04-01

    Neurovascular coupling is an important control mechanism in CBF regulation. New insights into the integrated relationship between synaptic activity, astrocytes Ca(2+) , and cerebral blood vessels using two-photon fluorescence imaging are slowly emerging. Here, we provide a brief overview of the current understandings and controversies regarding astrocytes in activity-dependent vasodilation. We highlight the key advantages and disadvantages of the in vitro and in vivo methodologies used to study this topic. In particular, we emphasize some of the drawbacks of acute brain slices as well as the confounding effects of anesthesia in in vivo preparations. To overcome these limitations, we discuss an emerging and important trend in imaging cell Ca(2+) and blood flow control in awake and behaving animals. This new approach may help resolve existing controversies on astrocyte control of arteriole diameter by providing a more physiologically relevant preparation to study CBF regulation.

  15. Imaging large-scale neural activity with cellular resolution in awake, mobile mice.

    PubMed

    Dombeck, Daniel A; Khabbaz, Anton N; Collman, Forrest; Adelman, Thomas L; Tank, David W

    2007-10-01

    We report a technique for two-photon fluorescence imaging with cellular resolution in awake, behaving mice with minimal motion artifact. The apparatus combines an upright, table-mounted two-photon microscope with a spherical treadmill consisting of a large, air-supported Styrofoam ball. Mice, with implanted cranial windows, are head restrained under the objective while their limbs rest on the ball's upper surface. Following adaptation to head restraint, mice maneuver on the spherical treadmill as their heads remain motionless. Image sequences demonstrate that running-associated brain motion is limited to approximately 2-5 microm. In addition, motion is predominantly in the focal plane, with little out-of-plane motion, making the application of a custom-designed Hidden-Markov-Model-based motion correction algorithm useful for postprocessing. Behaviorally correlated calcium transients from large neuronal and astrocytic populations were routinely measured, with an estimated motion-induced false positive error rate of <5%.

  16. [Long-term potentiation and unit evoked responses in the cingulate cortex of freely moving rats].

    PubMed

    Gorkin, A G; Reymann, K G; Aleksandrov, Iu I

    2002-01-01

    Long-term potentiation (LTP) of synaptic efficacy is considered to be the most probable physiological mechanism of long-term memory. However, lack of understanding of cellular and subcellular mechanisms of LTP induction in freely behaving animals does not correspond to the importance of the problem. It was tested whether the characteristics of potentiation in the cingulate cortex after tetanization of the subiculocingulate tract (SCT) meet the criteria of true LTP (that passes all known stages in its development and lasts for more than a day in freely-behaving animals). Additionally, characteristics of spike responses to SCT stimulation and the effects of application of different glutamate receptor blockers were studied. Without application of GABA receptor blockers, the LTP lasted for more than 24 hours. Application of NMDA glutamate receptor blockers significantly inhibited field potentials evoke by testing stimulation. Short-latency spike responses to SCT stimulation were recorded with low probability that increased with stimulation intensity. The obtained data reveal the possibility to compare the involvement of cingulate neurons in acquisition of adaptive behavior and changes in their spike responses during the LTP development in freely-moving rats. PMID:12528373

  17. A freely-moving monkey treadmill model

    NASA Astrophysics Data System (ADS)

    Foster, Justin D.; Nuyujukian, Paul; Freifeld, Oren; Gao, Hua; Walker, Ross; Ryu, Stephen I.; Meng, Teresa H.; Murmann, Boris; Black, Michael J.; Shenoy, Krishna V.

    2014-08-01

    Objective. Motor neuroscience and brain-machine interface (BMI) design is based on examining how the brain controls voluntary movement, typically by recording neural activity and behavior from animal models. Recording technologies used with these animal models have traditionally limited the range of behaviors that can be studied, and thus the generality of science and engineering research. We aim to design a freely-moving animal model using neural and behavioral recording technologies that do not constrain movement. Approach. We have established a freely-moving rhesus monkey model employing technology that transmits neural activity from an intracortical array using a head-mounted device and records behavior through computer vision using markerless motion capture. We demonstrate the flexibility and utility of this new monkey model, including the first recordings from motor cortex while rhesus monkeys walk quadrupedally on a treadmill. Main results. Using this monkey model, we show that multi-unit threshold-crossing neural activity encodes the phase of walking and that the average firing rate of the threshold crossings covaries with the speed of individual steps. On a population level, we find that neural state-space trajectories of walking at different speeds have similar rotational dynamics in some dimensions that evolve at the step rate of walking, yet robustly separate by speed in other state-space dimensions. Significance. Freely-moving animal models may allow neuroscientists to examine a wider range of behaviors and can provide a flexible experimental paradigm for examining the neural mechanisms that underlie movement generation across behaviors and environments. For BMIs, freely-moving animal models have the potential to aid prosthetic design by examining how neural encoding changes with posture, environment and other real-world context changes. Understanding this new realm of behavior in more naturalistic settings is essential for overall progress of basic

  18. Awake tracheal intubation using the Airtraq laryngoscope: a case series.

    PubMed

    Dimitriou, V K; Zogogiannis, I D; Liotiri, D G

    2009-08-01

    The Airtraq laryngoscope (AL) is a new single use indirect laryngoscope designed to facilitate tracheal intubation in anaesthetised patients either with normal or difficult airway anatomy. It is designed to provide a view of the glottis without alignment of the oral, pharyngeal and tracheal axes. We report four cases of successful awake tracheal intubation using the AL. The first case is a patient with severe ankylosing spondylitis and the other three cases with anticipated difficult airway. An awake intubation under sedation and topical airway anaesthesia was chosen. We consider that the AL can be used effectively to accomplish an awake intubation in patients with a suspected or known difficult airway and may be a useful alternative where other methods for awake intubation have failed or are not available.

  19. Freely Suspended Smectic Films in Aqueous Environment

    NASA Astrophysics Data System (ADS)

    Peddireddy, Karthik; Bahr, Christian

    2012-02-01

    Smectic liquid crystals easily form thin films which are freely suspended on a solid frame in air. These systems have been thoroughly studied for various purposes such as structural studies of smectic phases, investigating phase transitions in two-dimensional systems, and studying various physical properties of liquid crystals. In the present study, we explore the preparation of freely suspended smectic films in water. A prerequisite is the presence of a surfactant which accumulates at the liquid-crystal/water interface and induces a homeotropic anchoring of the director, so that the smectic layers align parallel to the two film surfaces. The presence of the surfactant might also serve as a handle to tune properties such as the surface tension of the films (which is hardly possible for freely suspended films in air). We study the formation of films in water using different frames and different surfactants, and we focus especially on the thinning behaviour which occurs when the temperature is increased towards the smectic - nematic or smectic - isotropic transition.

  20. Auditory Properties in the Parabelt Regions of the Superior Temporal Gyrus in the Awake Macaque Monkey: An Initial Survey

    PubMed Central

    Frey, Stephen; Ross, Deborah; Falchier, Arnaud; Hackett, Troy A.; Schroeder, Charles E.

    2015-01-01

    The superior temporal gyrus (STG) is on the inferior–lateral brain surface near the external ear. In macaques, 2/3 of the STG is occupied by an auditory cortical region, the “parabelt,” which is part of a network of inferior temporal areas subserving communication and social cognition as well as object recognition and other functions. However, due to its location beneath the squamous temporal bone and temporalis muscle, the STG, like other inferior temporal regions, has been a challenging target for physiological studies in awake-behaving macaques. We designed a new procedure for implanting recording chambers to provide direct access to the STG, allowing us to evaluate neuronal properties and their topography across the full extent of the STG in awake-behaving macaques. Initial surveys of the STG have yielded several new findings. Unexpectedly, STG sites in monkeys that were listening passively responded to tones with magnitudes comparable to those of responses to 1/3 octave band-pass noise. Mapping results showed longer response latencies in more rostral sites and possible tonotopic patterns parallel to core and belt areas, suggesting the reversal of gradients between caudal and rostral parabelt areas. These results will help further exploration of parabelt areas. PMID:25762661

  1. A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats

    PubMed Central

    Limnuson, Kanokwan; Narayan, Raj K.; Chiluwal, Amrit; Golanov, Eugene V.; Bouton, Chad E.; Li, Chunyan

    2016-01-01

    Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury. PMID:27594826

  2. A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats

    PubMed Central

    Limnuson, Kanokwan; Narayan, Raj K.; Chiluwal, Amrit; Golanov, Eugene V.; Bouton, Chad E.; Li, Chunyan

    2016-01-01

    Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury.

  3. A User-Configurable Headstage for Multimodality Neuromonitoring in Freely Moving Rats.

    PubMed

    Limnuson, Kanokwan; Narayan, Raj K; Chiluwal, Amrit; Golanov, Eugene V; Bouton, Chad E; Li, Chunyan

    2016-01-01

    Multimodal monitoring of brain activity, physiology, and neurochemistry is an important approach to gain insight into brain function, modulation, and pathology. With recent progress in micro- and nanotechnology, micro-nano-implants have become important catalysts in advancing brain research. However, to date, only a limited number of brain parameters have been measured simultaneously in awake animals in spite of significant recent progress in sensor technology. Here we have provided a cost and time effective approach to designing a headstage to conduct a multimodality brain monitoring in freely moving animals. To demonstrate this method, we have designed a user-configurable headstage for our micromachined multimodal neural probe. The headstage can reliably record direct-current electrocorticography (DC-ECoG), brain oxygen tension (PbrO2), cortical temperature, and regional cerebral blood flow (rCBF) simultaneously without significant signal crosstalk or movement artifacts for 72 h. Even in a noisy environment, it can record low-level neural signals with high quality. Moreover, it can easily interface with signal conditioning circuits that have high power consumption and are difficult to miniaturize. To the best of our knowledge, this is the first time where multiple physiological, biochemical, and electrophysiological cerebral variables have been simultaneously recorded from freely moving rats. We anticipate that the developed system will aid in gaining further insight into not only normal cerebral functioning but also pathophysiology of conditions such as epilepsy, stroke, and traumatic brain injury. PMID:27594826

  4. Anaesthesia for awake craniotomy: A retrospective study of 54 cases

    PubMed Central

    Sokhal, Navdeep; Rath, Girija Prasad; Chaturvedi, Arvind; Dash, Hari Hara; Bithal, Parmod Kumar; Chandra, P Sarat

    2015-01-01

    Background and Aims: The anaesthetic challenge of awake craniotomy is to maintain adequate sedation, analgesia, respiratory and haemodynamic stability in an awake patient who should be able to co-operate during intraoperative neurological assessment. The current literature, sharing the experience on awake craniotomy, in Indian context, is minimal. Hence, we carried out a retrospective study with the aim to review and analyse the anaesthetic management and perioperative complications in patients undergoing awake craniotomy, at our centre. Methods: Medical records of 54 patients who underwent awake craniotomy for intracranial lesions over a period of 10 years were reviewed, retrospectively. Data regarding anaesthetic management, intraoperative complications and post-operative course were recorded. Results: Propofol (81.5%) and dexmedetomidine (18.5%) were the main agents used for providing conscious sedation to facilitate awake craniotomy. Hypertension (16.7%) was the most commonly encountered complication during intraoperative period, followed by seizures (9.3%), desaturation (7.4%), tight brain (7.4%), and shivering (5.6%). The procedure had to be converted to general anaesthesia in one of patients owing to refractory brain bulge. The incidence of respiratory and haemodynamic complications were comparable in the both groups (P > 0.05). There was less incidence of intraoperative seizures in patients who received propofol (P = 0.03). In post-operative period, 20% of patients developed new motor deficit. Mean intensive care unit stay was 2.8 ± 1.9 day (1–14 days) and mean hospital stay was 7.0 ± 5.0 day (3–30 days). Conclusions: ‘Conscious sedation’ was the technique of choice for awake craniotomy, at our institute. Fentanyl, propofol, and dexmedetomidine were the main agents used for this purpose. Patients receiving propofol had less incidence of intraoperative seizure. Appropriate selection of patients, understanding the procedure of surgery, and judicious

  5. Awake craniotomy: A qualitative review and future challenges

    PubMed Central

    Ghazanwy, Mahmood; Chakrabarti, Rajkalyan; Tewari, Anurag; Sinha, Ashish

    2014-01-01

    Neurosurgery in awake patients incorporates newer technologies that require the anesthesiologists to update their skills and evolve their methodologies. They need effective communication skills and knowledge of selecting the right anesthetic drugs to ensure adequate analgesia, akinesia, along with patient satisfaction with the anesthetic conduct throughout the procedure. The challenge of providing adequate anesthetic care to an awake patient for intracranial surgery requires more than routine vigilance about anesthetic management. PMID:25422613

  6. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S.; Endres, Christopher J.; Foss, Catherine A.; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard, James S.; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander V.; Weisenberger, Andrew G.; Pomper, Martin G.

    2013-06-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a ^99mTc-pertechnetate phantom, ^99mTc-methylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand ^123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of ^123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  7. Molecular Imaging of Conscious, Unrestrained Mice with AwakeSPECT

    SciTech Connect

    Baba, Justin S; Endres, Christopher; Foss, Catherine; Nimmagadda, Sridhar; Jung, Hyeyun; Goddard Jr, James Samuel; Lee, Seung Joon; McKisson, John; Smith, Mark F.; Stolin, Alexander; Weisenberger, Andrew G.; Pomper, Martin

    2013-01-01

    We have developed a SPECT imaging system, AwakeSPECT, to enable molecular brain imaging of untrained mice that are conscious, unanesthetized, and unrestrained. We accomplished this with head tracking and motion correction techniques. Methods: The capability of the system for motion-corrected imaging was demonstrated with a 99mTc-pertechnetate phantom, 99mTcmethylene diphosphonate bone imaging, and measurement of the binding potential of the dopamine transporter radioligand 123I-ioflupane in mouse brain in the awake and anesthetized (isoflurane) states. Stress induced by imaging in the awake state was assessed through measurement of plasma corticosterone levels. Results: AwakeSPECT provided high-resolution bone images reminiscent of those obtained from CT. The binding potential of 123I-ioflupane in the awake state was on the order of 50% of that obtained with the animal under anesthesia, consistent with previous studies in nonhuman primates. Levels of stress induced were on the order of those seen in other behavioral tasks and imaging studies of awake animals. Conclusion: These results demonstrate the feasibility of SPECT molecular brain imaging of mice in the conscious, unrestrained state and demonstrate the effects of isoflurane anesthesia on radiotracer uptake.

  8. Mapping brain function in freely moving subjects

    PubMed Central

    Holschneider, Daniel P.; Maarek, Jean-Michel I.

    2014-01-01

    Expression of many fundamental mammalian behaviors such as, for example, aggression, mating, foraging or social behaviors, depend on locomotor activity. A central dilemma in the functional neuroimaging of these behaviors has been the fact that conventional neuroimaging techniques generally rely on immobilization of the subject, which extinguishes all but the simplest activity. Ideally, imaging could occur in freely moving subjects, while presenting minimal interference with the subject’s natural behavior. Here we provide an overview of several approaches that have been undertaken in the past to achieve this aim in both tethered and freely moving animals, as well as in nonrestrained human subjects. Applications of specific radiotracers to single photon emission computed tomography and positron emission tomography are discussed in which brain activation is imaged after completion of the behavioral task and capture of the tracer. Potential applications to clinical neuropsychiatry are discussed, as well as challenges inherent to constraint-free functional neuroimaging. Future applications of these methods promise to increase our understanding of the neural circuits underlying mammalian behavior in health and disease. PMID:15465134

  9. Implantable electrode for recording nerve signals in awake animals

    NASA Technical Reports Server (NTRS)

    Ninomiya, I.; Yonezawa, Y.; Wilson, M. F.

    1976-01-01

    An implantable electrode assembly consisting of collagen and metallic electrodes was constructed to measure simultaneously neural signals from the intact nerve and bioelectrical noises in awake animals. Mechanical artifacts, due to bodily movement, were negligibly small. The impedance of the collagen electrodes, measured in awake cats 6-7 days after implantation surgery, ranged from 39.8-11.5 k ohms at a frequency range of 20-5 kHz. Aortic nerve activity and renal nerve activity, measured in awake conditions using the collagen electrode, showed grouped activity synchronous with the cardiac cycle. Results indicate that most of the renal nerve activity was from postganglionic sympathetic fibers and was inhibited by the baroceptor reflex in the same cardiac cycle.

  10. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    S. Lee, B. Kross, D. Weisenberger, J. McKisson, J.S. Goddard, J.S. Baba, M.S. Smith

    2012-02-01

    Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  11. Dual-headed SPECT for awake animal brain imaging

    SciTech Connect

    Lee, Seung Joon; Weisenberger, A G; McKisson, J; Goddard Jr, James Samuel; Baba, Justin S; Smith, M F

    2011-01-01

    Abstract- Motion-corrected awake animal imaging is needed for normal-state investigations of models of neurological disease and brain activity. The awake animal brain SPECT/CT system, AwakeSPECT at Johns Hopkins University has in the past used a single gamma camera for imaging. Enhancements have been made by adding a pinhole collimator to the second gamma camera at the opposite side which has been previously equipped parallel hole collimator. Geometry calibration was performed using a custom built quality control phantom containing three Co-57 point sources and applied to the tomographic reconstruction code. Hot-rod phantom scans with Tc-99m were performed to test sensitivity and resolution improvements. The reconstruction results show significant resolution and sensitivity improvements.

  12. Virtual help for real surgery: the case of awake surgery.

    PubMed

    Albani, Giovanni; Cipresso, Pietro; Gaggioli, Andrea; Serino, Silvia; Vigna, Cinzia; Priano, Lorenzo; Mauro, Alessandro; Franzini, Angelo; Riva, Giuseppe

    2012-01-01

    Awake surgery can be highly stressful for patients. In fact, being awake, patients could perceive that the environmental demands are taxing or exceed their adaptive abilities. We proposed the use of Virtual Reality as a functional and effective tool for a new class of clinical applications aimed at helping patients to cope with these specific stressful situations. Using coping skills that have been learnt during the virtual experience, patients can reduce their psychological stress and improve their collaboration and - in general - the outcome of the intervention.

  13. A method for closed-loop presentation of sensory stimuli conditional on the internal brain-state of awake animals

    PubMed Central

    Rutishauser, Ueli; Kotowicz, Andreas; Laurent, Gilles

    2013-01-01

    Brain activity often consists of interactions between internal—or on-going—and external—or sensory—activity streams, resulting in complex, distributed patterns of neural activity. Investigation of such interactions could benefit from closed-loop experimental protocols in which one stream can be controlled depending on the state of the other. We describe here methods to present rapid and precisely timed visual stimuli to awake animals, conditional on features of the animal’s on-going brain state; those features are the presence, power and phase of oscillations in local field potentials (LFP). The system can process up to 64 channels in real time. We quantified its performance using simulations, synthetic data and animal experiments (chronic recordings in the dorsal cortex of awake turtles). The delay from detection of an oscillation to the onset of a visual stimulus on an LCD screen was 47.5 ms and visual-stimulus onset could be locked to the phase of ongoing oscillations at any frequency ≤40 Hz. Our software’s architecture is flexible, allowing on-the-fly modifications by experimenters and the addition of new closed-loop control and analysis components through plugins. The source code of our system “StimOMatic” is available freely as open-source. PMID:23473800

  14. An Experimental Model of Vasovagal Syncope Induces Cerebral Hypoperfusion and Fainting-Like Behavior in Awake Rats

    PubMed Central

    McBride, Devin W.; Reis, Cesar; Frank, Ethan; Klebe, Damon W.; Zhang, John H.; Applegate, Richard

    2016-01-01

    Vasovagal syncope, a contributing factor to elderly falls, is the transient loss of consciousness caused by decreased cerebral perfusion. Vasovagal syncope is characterized by hypotension, bradycardia, and reduced cerebral blood flow, resulting in fatigue, altered coordination, and fainting. The purpose of this study is to develop an animal model which is similar to human vasovagal syncope and establish an awake animal model of vasovagal syncope. Male Sprague-Dawley rats were subjected to sinusoidal galvanic vestibular stimulation (sGVS). Blood pressure, heart rate, and cerebral blood flow were monitored before, during, and post-stimulation. sGVS resulted in hypotension, bradycardia, and decreased cerebral blood flow. One cohort of animals was subjected to sGVS while freely moving. sGVS in awake animals produced vasovagal syncope-like symptoms, including fatigue and uncoordinated movements; two animals experienced spontaneous falling. Another cohort of animals was preconditioned with isoflurane for several days before being subjected to sGVS. Isoflurane preconditioning before sGVS did not prevent sGVS-induced hypotension or bradycardia, yet isoflurane preconditioning attenuated sGVS-induced cerebral blood flow reduction. The sGVS rat model mimics elements of human vasovagal syncope pathophysiology (hypotension, bradycardia, and decreased cerebral perfusion), including behavioral symptoms such as fatigue and altered balance. This study indicates that the sGVS rat model is similar to human vasovagal syncope and that therapies directed at preventing cerebral hypoperfusion may decrease syncopal episodes and reduce injuries from syncopal falls. PMID:27658057

  15. Reverse Translation of Clinical Electrophysiological Biomarkers in Behaving Rodents under Acute and Chronic NMDA Receptor Antagonism

    PubMed Central

    Sullivan, Elyse M; Timi, Patricia; Hong, L Elliot; O'Donnell, Patricio

    2015-01-01

    Electroencephalogram (EEG) stands out as a highly translational tool for psychiatric research, yet rodent and human EEG are not typically obtained in the same way. In this study we developed a tool to record skull EEG in awake-behaving rats in a similar manner to how human EEG are obtained and then used this technique to test whether acute NMDA receptor antagonism alters rodent EEG signals in a similar manner as in humans. Acute MK-801 treatment elevated gamma power and reduced beta band power, which closely mirrored EEG data from healthy volunteers receiving acute ketamine. To explore the mechanisms behind these oscillatory changes, we examined the effects of GABA-A receptor blockade, finding that picrotoxin (PTX) recapitulated the decrease in sound-evoked beta oscillations observed with acute MK-801, but did not produce changes in gamma band power. Chronic treatment with either PTX or MK-801 did not affect frequency-specific oscillatory activity when tested 24 h after the last drug injection, but decreased total broadband oscillatory power. Overall, this study validated a novel platform for recording rodent EEG and demonstrated similar oscillatory changes after acute NMDA receptor antagonism in both humans and rodents, suggesting that skull EEG may be a powerful tool for further translational studies. PMID:25176166

  16. Measurement of Electroretinograms and Visually Evoked Potentials in Awake Moving Mice

    PubMed Central

    Tokashiki, Naoyuki; Daigaku, Reiko; Tabata, Kitako; Sugano, Eriko; Tomita, Hiroshi; Nakazawa, Toru

    2016-01-01

    The development of new treatments for intractable retinal diseases requires reliable functional assessment tools for animal models. In vivo measurements of neural activity within visual pathways, including electroretinogram (ERG) and visually evoked potential (VEP) recordings, are commonly used for such purposes. In mice, the ERG and VEPs are usually recorded under general anesthesia, a state that may alter sensory transduction and neurotransmission, but seldom in awake freely moving mice. Therefore, it remains unknown whether the electrophysiological assessment of anesthetized mice accurately reflects the physiological function of the visual pathway. Herein, we describe a novel method to record the ERG and VEPs simultaneously in freely moving mice by immobilizing the head using a custom-built restraining device and placing a rotatable cylinder underneath to allow free running or walking during recording. Injection of the commonly used anesthetic mixture xylazine plus ketamine increased and delayed ERG oscillatory potentials by an average of 67.5% and 36.3%, respectively, compared to unanesthetized mice, while having minimal effects on the a-wave and b-wave. Similarly, components of the VEP were enhanced and delayed by up to 300.2% and 39.3%, respectively, in anesthetized mice. Our method for electrophysiological recording in conscious mice is a sensitive and robust means to assess visual function. It uses a conventional electrophysiological recording system and a simple platform that can be built in any laboratory at low cost. Measurements using this method provide objective indices of mouse visual function with high precision and stability, unaffected by anesthetics. PMID:27257864

  17. Closing capacity in awake and anesthetized-paralyzed man.

    PubMed

    Juno, J; Marsh, H M; Knopp, T J; Rehder, K

    1978-02-01

    Functional residual capacity (FRC), closing capacity (CC), and (FRC--CC) were determined in 61 supine patients using the 133Xe bolus test. In 28 of the 61 patients measurements were made both while the patients were awake and during anesthesia-paralysis. Both FRC and CC decreased significantly after induction of anesthesia-paralysis. The magnitude of the reduction in CC, but not of FRC, was dependent on the relationship between FRC and CC in the awake state. Patients whose FRC was larger than their CC while awake (group I) showed less decrease in CC than FRC, i.e., (FRC--CC) decreased. By contrast, those patients whose CC was larger than their FRC while awake (group II) showed a greater decrease in CC than in FRC, i.e., (FRC--CC) became less negative. The reduction in CC after induction of anesthesia-paralysis may result from an increased elastic recoil of the lung. The larger reduction in CC in group II patients may have been due to a larger increase in elastic recoil, possibly due to the development of atelactasis.

  18. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    PubMed

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery.

  19. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    PubMed

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery. PMID:26249245

  20. Measuring and tracking eye movements of a behaving archer fish by real-time stereo vision.

    PubMed

    Ben-Simon, Avi; Ben-Shahar, Ohad; Segev, Ronen

    2009-11-15

    The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. This behavior also raises many important questions, such as the fish's ability to compensate for air-water refraction and the neural mechanisms underlying target acquisition. While many such questions remain open, significant insights towards solving them can be obtained by tracking the eye and body movements of freely behaving fish. Unfortunately, existing tracking methods suffer from either a high level of invasiveness or low resolution. Here, we present a video-based eye tracking method for accurately and remotely measuring the eye and body movements of a freely moving behaving fish. Based on a stereo vision system and a unique triangulation method that corrects for air-glass-water refraction, we are able to measure a full three-dimensional pose of the fish eye and body with high temporal and spatial resolution. Our method, being generic, can be applied to studying the behavior of marine animals in general. We demonstrate how data collected by our method may be used to show that the hunting behavior of the archer fish is composed of surfacing concomitant with rotating the body around the direction of the fish's fixed gaze towards the target, until the snout reaches in the correct shooting position at water level.

  1. Measuring and tracking eye movements of a behaving archer fish by real-time stereo vision.

    PubMed

    Ben-Simon, Avi; Ben-Shahar, Ohad; Segev, Ronen

    2009-11-15

    The archer fish (Toxotes chatareus) exhibits unique visual behavior in that it is able to aim at and shoot down with a squirt of water insects resting on the foliage above water level and then feed on them. This extreme behavior requires excellent visual acuity, learning, and tight synchronization between the visual system and body motion. This behavior also raises many important questions, such as the fish's ability to compensate for air-water refraction and the neural mechanisms underlying target acquisition. While many such questions remain open, significant insights towards solving them can be obtained by tracking the eye and body movements of freely behaving fish. Unfortunately, existing tracking methods suffer from either a high level of invasiveness or low resolution. Here, we present a video-based eye tracking method for accurately and remotely measuring the eye and body movements of a freely moving behaving fish. Based on a stereo vision system and a unique triangulation method that corrects for air-glass-water refraction, we are able to measure a full three-dimensional pose of the fish eye and body with high temporal and spatial resolution. Our method, being generic, can be applied to studying the behavior of marine animals in general. We demonstrate how data collected by our method may be used to show that the hunting behavior of the archer fish is composed of surfacing concomitant with rotating the body around the direction of the fish's fixed gaze towards the target, until the snout reaches in the correct shooting position at water level. PMID:19698749

  2. Oxytocin and vasopressin modulation of the neural correlates of motivation and emotion: results from functional MRI studies in awake rats.

    PubMed

    Febo, Marcelo; Ferris, Craig F

    2014-09-11

    Oxytocin and vasopressin modulate a range of species typical behavioral functions that include social recognition, maternal-infant attachment, and modulation of memory, offensive aggression, defensive fear reactions, and reward seeking. We have employed novel functional magnetic resonance mapping techniques in awake rats to explore the roles of these neuropeptides in the maternal and non-maternal brain. Results from the functional neuroimaging studies that are summarized here have directly and indirectly confirmed and supported previous findings. Oxytocin is released within the lactating rat brain during suckling stimulation and activates specific subcortical networks in the maternal brain. Both vasopressin and oxytocin modulate brain regions involved unconditioned fear, processing of social stimuli and the expression of agonistic behaviors. Across studies there are relatively consistent brain networks associated with internal motivational drives and emotional states that are modulated by oxytocin and vasopressin. This article is part of a Special Issue entitled Oxytocin and Social Behav.

  3. Awake dynamics and brain-wide direct inputs of hypothalamic MCH and orexin networks

    PubMed Central

    González, J. Antonio; Iordanidou, Panagiota; Strom, Molly; Adamantidis, Antoine; Burdakov, Denis

    2016-01-01

    The lateral hypothalamus (LH) controls energy balance. LH melanin-concentrating-hormone (MCH) and orexin/hypocretin (OH) neurons mediate energy accumulation and expenditure, respectively. MCH cells promote memory and appropriate stimulus-reward associations; their inactivation disrupts energy-optimal behaviour and causes weight loss. However, MCH cell dynamics during wakefulness are unknown, leaving it unclear if they differentially participate in brain activity during sensory processing. By fiberoptic recordings from molecularly defined populations of LH neurons in awake freely moving mice, we show that MCH neurons generate conditional population bursts. This MCH cell activity correlates with novelty exploration, is inhibited by stress and is inversely predicted by OH cell activity. Furthermore, we obtain brain-wide maps of monosynaptic inputs to MCH and OH cells, and demonstrate optogenetically that VGAT neurons in the amygdala and bed nucleus of stria terminalis inhibit MCH cells. These data reveal cell-type-specific LH dynamics during sensory integration, and identify direct neural controllers of MCH neurons. PMID:27102565

  4. Awake dynamics and brain-wide direct inputs of hypothalamic MCH and orexin networks.

    PubMed

    González, J Antonio; Iordanidou, Panagiota; Strom, Molly; Adamantidis, Antoine; Burdakov, Denis

    2016-01-01

    The lateral hypothalamus (LH) controls energy balance. LH melanin-concentrating-hormone (MCH) and orexin/hypocretin (OH) neurons mediate energy accumulation and expenditure, respectively. MCH cells promote memory and appropriate stimulus-reward associations; their inactivation disrupts energy-optimal behaviour and causes weight loss. However, MCH cell dynamics during wakefulness are unknown, leaving it unclear if they differentially participate in brain activity during sensory processing. By fiberoptic recordings from molecularly defined populations of LH neurons in awake freely moving mice, we show that MCH neurons generate conditional population bursts. This MCH cell activity correlates with novelty exploration, is inhibited by stress and is inversely predicted by OH cell activity. Furthermore, we obtain brain-wide maps of monosynaptic inputs to MCH and OH cells, and demonstrate optogenetically that VGAT neurons in the amygdala and bed nucleus of stria terminalis inhibit MCH cells. These data reveal cell-type-specific LH dynamics during sensory integration, and identify direct neural controllers of MCH neurons.

  5. Turrialba volcano: awaking indications of possible unrest

    NASA Astrophysics Data System (ADS)

    González, G.; Ramirez, C. J.; Mora-Amador, R.; Rouwet, D.; Mora, R.; Alpizar, Y.; Picado, C.

    2012-12-01

    Based on historical descriptions and reports, Turrialba volcano has presented events like incandescence, SO2 combustion, phreatic eruptions, that preceded the only historical magmatic eruption (1864-1866), this VEI value 2 eruption covered a surface area of 3400 km2, successively the volcano enter in a period of calm. During most of the 80's and 90's the volcano was under low seismic activity and low temperature fumaroles (<100°C). At the end of the 90's and the firsts years of 00's there was a small changes on fumarole fields sizes and small increase on temperature and microquakes, but it was after 2005 that the volcano increased the seismicity from 10 to 100 diary microquakes, accompained by a higher degassing, acid rain and fumaroles over ≈250°C. On January 5th, 2010 the volcano had a serial of phreatic eruptions, which formed an elongated intracrateric vent named "Boquete 2010", at the NW crater, which reached maximum temperatures of 560°C, also incandescence at night with sporadically emission of non-juvenile ashes. Later on June 2011, "Boquete 2010" temperature decreased to ≈300°C, but some new fumaroles appeared in the NW intracrater with a maximum temperature of 531°C, also with incandescence and SO2 blue combustion gases. Finally on January 11, 2012 during a fieldwork caused by thermal images showing the increase on temperature of fumaroles (≈250°C to ≈450°C), a couple of active sulphur flows of at least 100m long appeared, that flows behaved like a newtonian liquid with similar setting of a pahoehoe lava. Next day on January 12, the volcano had a serial of phreatic eruptions with emission of non-juvenile ashes and formed a new vent ("Boquete 2012") in outer eastern wall of the NW crater, that reach temperatures of 780°C also with incandescence and SO2 combustion gases.

  6. Novelty and anxiolytic drugs dissociate two components of hippocampal theta in behaving rats.

    PubMed

    Wells, Christine E; Amos, Doran P; Jeewajee, Ali; Douchamps, Vincent; Rodgers, John; O'Keefe, John; Burgess, Neil; Lever, Colin

    2013-05-15

    Hippocampal processing is strongly implicated in both spatial cognition and anxiety and is temporally organized by the theta rhythm. However, there has been little attempt to understand how each type of processing relates to the other in behaving animals, despite their common substrate. In freely moving rats, there is a broadly linear relationship between hippocampal theta frequency and running speed over the normal range of speeds used during foraging. A recent model predicts that spatial-translation-related and arousal/anxiety-related mechanisms of hippocampal theta generation underlie dissociable aspects of the theta frequency-running speed relationship (the slope and intercept, respectively). Here we provide the first confirmatory evidence: environmental novelty decreases slope, whereas anxiolytic drugs reduce intercept. Variation in slope predicted changes in spatial representation by CA1 place cells and novelty-responsive behavior. Variation in intercept predicted anxiety-like behavior. Our findings isolate and doubly dissociate two components of theta generation that operate in parallel in behaving animals and link them to anxiolytic drug action, novelty, and the metric for self-motion. PMID:23678110

  7. Novelty and anxiolytic drugs dissociate two components of hippocampal theta in behaving rats.

    PubMed

    Wells, Christine E; Amos, Doran P; Jeewajee, Ali; Douchamps, Vincent; Rodgers, John; O'Keefe, John; Burgess, Neil; Lever, Colin

    2013-05-15

    Hippocampal processing is strongly implicated in both spatial cognition and anxiety and is temporally organized by the theta rhythm. However, there has been little attempt to understand how each type of processing relates to the other in behaving animals, despite their common substrate. In freely moving rats, there is a broadly linear relationship between hippocampal theta frequency and running speed over the normal range of speeds used during foraging. A recent model predicts that spatial-translation-related and arousal/anxiety-related mechanisms of hippocampal theta generation underlie dissociable aspects of the theta frequency-running speed relationship (the slope and intercept, respectively). Here we provide the first confirmatory evidence: environmental novelty decreases slope, whereas anxiolytic drugs reduce intercept. Variation in slope predicted changes in spatial representation by CA1 place cells and novelty-responsive behavior. Variation in intercept predicted anxiety-like behavior. Our findings isolate and doubly dissociate two components of theta generation that operate in parallel in behaving animals and link them to anxiolytic drug action, novelty, and the metric for self-motion.

  8. Novelty and Anxiolytic Drugs Dissociate Two Components of Hippocampal Theta in Behaving Rats

    PubMed Central

    Wells, Christine E.; Amos, Doran P.; Jeewajee, Ali; Douchamps, Vincent; Rodgers, John; O’Keefe, John; Burgess, Neil; Lever, Colin

    2013-01-01

    Hippocampal processing is strongly implicated in both spatial cognition and anxiety and is temporally organized by the theta rhythm. However, there has been little attempt to understand how each type of processing relates to the other in behaving animals, despite their common substrate. In freely moving rats, there is a broadly linear relationship between hippocampal theta frequency and running speed over the normal range of speeds used during foraging. A recent model predicts that spatial-translation-related and arousal/anxiety-related mechanisms of hippocampal theta generation underlie dissociable aspects of the theta frequency–running speed relationship (the slope and intercept, respectively). Here we provide the first confirmatory evidence: environmental novelty decreases slope, whereas anxiolytic drugs reduce intercept. Variation in slope predicted changes in spatial representation by CA1 place cells and novelty-responsive behavior. Variation in intercept predicted anxiety-like behavior. Our findings isolate and doubly dissociate two components of theta generation that operate in parallel in behaving animals and link them to anxiolytic drug action, novelty, and the metric for self-motion. PMID:23678110

  9. High-throughput mapping of brain-wide activity in awake and drug-responsive vertebrates.

    PubMed

    Lin, Xudong; Wang, Shiqi; Yu, Xudong; Liu, Zhuguo; Wang, Fei; Li, Wai Tsun; Cheng, Shuk Han; Dai, Qiuyun; Shi, Peng

    2015-02-01

    The reconstruction of neural activity across complete neural circuits, or brain activity mapping, has great potential in both fundamental and translational neuroscience research. Larval zebrafish, a vertebrate model, has recently been demonstrated to be amenable to whole brain activity mapping in behaving animals. Here we demonstrate a microfluidic array system ("Fish-Trap") that enables high-throughput mapping of brain-wide activity in awake larval zebrafish. Unlike the commonly practiced larva-processing methods using a rigid gel or a capillary tube, which are laborious and time-consuming, the hydrodynamic design of our microfluidic chip allows automatic, gel-free, and anesthetic-free processing of tens of larvae for microscopic imaging with single-cell resolution. Notably, this system provides the capability to directly couple pharmaceutical stimuli with real-time recording of neural activity in a large number of animals, and the local and global effects of pharmacoactive drugs on the nervous system can be directly visualized and evaluated by analyzing drug-induced functional perturbation within or across different brain regions. Using this technology, we tested a set of neurotoxin peptides and obtained new insights into how to exploit neurotoxin derivatives as therapeutic agents. The novel and versatile "Fish-Trap" technology can be readily unitized to study other stimulus (optical, acoustic, or physical) associated functional brain circuits using similar experimental strategies.

  10. Integration of silicon-based neural probes and micro-drive arrays for chronic recording of large populations of neurons in behaving animals

    NASA Astrophysics Data System (ADS)

    Michon, Frédéric; Aarts, Arno; Holzhammer, Tobias; Ruther, Patrick; Borghs, Gustaaf; McNaughton, Bruce; Kloosterman, Fabian

    2016-08-01

    Objective. Understanding how neuronal assemblies underlie cognitive function is a fundamental question in system neuroscience. It poses the technical challenge to monitor the activity of populations of neurons, potentially widely separated, in relation to behaviour. In this paper, we present a new system which aims at simultaneously recording from a large population of neurons from multiple separated brain regions in freely behaving animals. Approach. The concept of the new device is to combine the benefits of two existing electrophysiological techniques, i.e. the flexibility and modularity of micro-drive arrays and the high sampling ability of electrode-dense silicon probes. Main results. Newly engineered long bendable silicon probes were integrated into a micro-drive array. The resulting device can carry up to 16 independently movable silicon probes, each carrying 16 recording sites. Populations of neurons were recorded simultaneously in multiple cortical and/or hippocampal sites in two freely behaving implanted rats. Significance. Current approaches to monitor neuronal activity either allow to flexibly record from multiple widely separated brain regions (micro-drive arrays) but with a limited sampling density or to provide denser sampling at the expense of a flexible placement in multiple brain regions (neural probes). By combining these two approaches and their benefits, we present an alternative solution for flexible and simultaneous recordings from widely distributed populations of neurons in freely behaving rats.

  11. Implantable fiber-optic interface for parallel multisite long-term optical dynamic brain interrogation in freely moving mice

    NASA Astrophysics Data System (ADS)

    Doronina-Amitonova, L. V.; Fedotov, I. V.; Ivashkina, O. I.; Zots, M. A.; Fedotov, A. B.; Anokhin, K. V.; Zheltikov, A. M.

    2013-11-01

    Seeing the big picture of functional responses within large neural networks in a freely functioning brain is crucial for understanding the cellular mechanisms behind the higher nervous activity, including the most complex brain functions, such as cognition and memory. As a breakthrough toward meeting this challenge, implantable fiber-optic interfaces integrating advanced optogenetic technologies and cutting-edge fiber-optic solutions have been demonstrated, enabling a long-term optogenetic manipulation of neural circuits in freely moving mice. Here, we show that a specifically designed implantable fiber-optic interface provides a powerful tool for parallel long-term optical interrogation of distinctly separate, functionally different sites in the brain of freely moving mice. This interface allows the same groups of neurons lying deeply in the brain of a freely behaving mouse to be reproducibly accessed and optically interrogated over many weeks, providing a long-term dynamic detection of genome activity in response to a broad variety of pharmacological and physiological stimuli.

  12. Enclosure for small animals during awake animal imaging

    DOEpatents

    Goddard, Jr., James S

    2013-11-26

    An enclosure or burrow restrains an awake animal during an imaging procedure. A tubular body, made from a radiolucent material that does not attenuate x-rays or gamma rays, accepts an awake animal. A proximal end of the body includes an attachment surface that corresponds to an attachment surface of an optically transparent and optically uniform window. An anti-reflective coating may be applied to an inner surface, an outer surface, or both surfaces of the window. Since the window is a separate element of the enclosure and it is not integrally formed as part of the body, it can be made with optically uniform thickness properties for improved motion tracking of markers on the animal with a camera during the imaging procedure. The motion tracking information is then used to compensate for animal movement in the image.

  13. Methylphenidate-induced awake bruxism: a case report.

    PubMed

    Sivri, Rukiye Çolak; Bilgiç, Ayhan

    2015-01-01

    Methylphenidate (MPH) is a stimulant that is commonly used in the treatment of attention-deficit/hyperactivity disorder in children and adults. Several reports are available regarding the relationship of MPH use and sleep bruxism. We report the case of a 9-year-old boy who presented with severe awake bruxism after his second dose of sustained release form of MPH treatment, which was confirmed on rechallenge. This is the first report of its kind showing such relationship in the literature.

  14. [A Case of Psychogenic Tremor during Awake Craniotomy].

    PubMed

    Kujirai, Kazumasa; Kamata, Kotoe; Uno, Toshihiro; Hamada, Keiko; Ozaki, Makoto

    2016-01-01

    A 31-year-old woman with a left frontal and parietal brain tumor underwent awake craniotomy. Propofol/remifentanil general anesthesia was induced. Following craniotomy, anesthetic administrations ceased. The level of consciousness was sufficient and she was not agitated. However, the patient complained of nausea 70 minutes into the awake phase. Considering the adverse effects of antiemetics and the upcoming surgical strategy, we did not give any medications. Nausea disappeared spontaneously while the operation was suspended. When surgical intervention extended to the left caudate nucleus, involuntary movement, classified as a tremor, with 5-6 Hz frequency, abruptly occurred on her left forearm. The patient showed emotional distress. Tremor appeared on her right forearm and subsequently spread to her lower extremities. Intravenous midazolam and fentanyl could not reduce her psychological stress. Since the tremor disturbed microscopic observation, general anesthesia was induced. Consequently, the tremor disappeared and did not recur. Based on the anatomical ground and the medication status, her involuntary movement was diagnosed as psychogenic tremor. Various factors can induce involuntary movements. In fact, intraoperative management of nausea and vomiting takes priority during awake craniotomy, but we should be reminded that some antiemetics potentially induce involuntary movement that could be caused by surgery around basal ganglia. PMID:27004392

  15. Presurgical Rehearsals for Patients Considering "Awake" Deep Brain Stimulation.

    PubMed

    Falconer, Ramsey A; Rogers, Sean L; Brewer, Cristie M; Piscitani, Franco; Shenai, Mahesh B

    2016-01-01

    Simulated surgical environments are rapidly gaining adoption in training students, residents, and members of specialized surgical teams. However, minimal attention has been given to the use of simulated surgical environments to educate patients on surgical processes, particularly procedures that require the active participation of the patient. "Awake" neurosurgery provides a unique situation in which patients openly participate in their operation. We describe a case report, in which a 62-year-old male was referred for "awake" deep brain stimulation implantation, in relation to medically refractory Parkinson's disease. The patient had significant concerns regarding anxiety and claustrophobia, and toleration of the "awake" procedure. Consequently, we designed a simulated OR environment and process, to recreate the physical experience of the procedure, with minimal cost or risk. This experience was crucial in determining the care plan, as after this experience, the patient opted for an "asleep" alternative. Thus, in certain settings, presurgical rehearsals may have a dramatic impact in the overall course of care. PMID:27532036

  16. Hour-long adaptation in the awake early visual system

    PubMed Central

    Stoelzel, Carl R.; Huff, Joseph M.; Bereshpolova, Yulia; Zhuang (庄骏), Jun; Hei (黑晓娟), Xiaojuan; Alonso, Jose-Manuel

    2015-01-01

    Sensory adaptation serves to adjust awake brains to changing environments on different time scales. However, adaptation has been studied traditionally under anesthesia and for short time periods. Here, we demonstrate in awake rabbits a novel type of sensory adaptation that persists for >1 h and acts on visual thalamocortical neurons and their synapses in the input layers of the visual cortex. Following prolonged visual stimulation (10–30 min), cells in the dorsal lateral geniculate nucleus (LGN) show a severe and prolonged reduction in spontaneous firing rate. This effect is bidirectional, and prolonged visually induced response suppression is followed by a prolonged increase in spontaneous activity. The reduction in thalamic spontaneous activity following prolonged visual activation is accompanied by increases in 1) response reliability, 2) signal detectability, and 3) the ratio of visual signal/spontaneous activity. In addition, following such prolonged activation of an LGN neuron, the monosynaptic currents generated by thalamic impulses in layer 4 of the primary visual cortex are enhanced. These results demonstrate that in awake brains, prolonged sensory stimulation can have a profound, long-lasting effect on the information conveyed by thalamocortical inputs to the visual cortex. PMID:26108950

  17. The evolution of brain surgery on awake patients.

    PubMed

    Surbeck, Werner; Hildebrandt, Gerhard; Duffau, Hugues

    2015-01-01

    In the early days of modern neurological surgery, the inconveniences and potential dangers of general anesthesia by chloroform and ether using the so-called "open-drop technique" led to the quest for alternative methods of anesthesia. Besides preventing the feared side effects, the introduction of regional anesthesia revealed another decisive advantage over general anesthesia in neurosurgery: While intraoperative direct cortical stimulation under general anesthesia could only delineate the motor area (by evocation of contralateral muscular contraction), now, the awake patients were able to report sensations elicited by this method. These properties advanced regional anesthesia to the regimen of choice for cranial surgeries in the first half of the 20th century. While technical advances and new drugs led to a progressive return to general anesthesia for neurosurgical procedures, the use of regional anesthesia for epilepsy surgery has only decreased in recent decades. Meanwhile, awake craniotomies regained popularity in oncologically motivated surgeries, especially in craniotomies for diffuse low-grade gliomas. Intraoperative mapping of brain functions using electrical stimulation in awake patients enables not only for increased tumor removal while preserving the functional status of the patients but also opens a window to cognitive neuroscience. Observations during such interventions and their correlation with both pre - and postoperative neuropsychological examinations and functional neuroimaging is progressively leading to new insights into the complex functional anatomy of the human brain. Furthermore, it broadens our knowledge on cerebral network reorganization in the presence of disease-with implications for all disciplines of clinical neuroscience.

  18. Measuring Whole-Brain Neural Dynamics and Behavior of Freely-Moving C. elegans

    NASA Astrophysics Data System (ADS)

    Shipley, Frederick; Nguyen, Jeffrey; Plummer, George; Shaevitz, Joshua; Leifer, Andrew

    2015-03-01

    Bridging the gap between an organism's neural dynamics and its ultimate behavior is the fundamental goal of neuroscience. Previously, to probe neural dynamics, we have been limited to measuring from a limited number of neurons, whether by electrode or optogenetic measurements. Here we present an instrument to simultaneously monitor neural activity from every neuron in a freely moving Caenorhabditis elegans' head, while recording behavior at the same time. Previously, whole-brain imaging has been demonstrated in C. elegans, but only in restrained and anesthetized animals (1). For studying neural coding of behavior it is crucial to study neural activity in freely behaving animals. Neural activity is recorded optically from cells expressing a calcium indicator, GCaMP6. Real time computer vision tracks the worm's position in x-y, while a piezo stage sweeps through the brain in z, yielding five brain-volumes per second. Behavior is recorded under infrared, dark-field imaging. This tool will allow us to directly correlate neural activity with behavior and we will present progress toward this goal. Thank you to the Simons Foundation and Princeton University for supporting this research.

  19. Long-term behavioral tracking of freely swimming weakly electric fish.

    PubMed

    Jun, James J; Longtin, André; Maler, Leonard

    2014-03-06

    Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals' access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal's body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal's body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors.

  20. Long-term Behavioral Tracking of Freely Swimming Weakly Electric Fish

    PubMed Central

    Jun, James J.; Longtin, André; Maler, Leonard

    2014-01-01

    Long-term behavioral tracking can capture and quantify natural animal behaviors, including those occurring infrequently. Behaviors such as exploration and social interactions can be best studied by observing unrestrained, freely behaving animals. Weakly electric fish (WEF) display readily observable exploratory and social behaviors by emitting electric organ discharge (EOD). Here, we describe three effective techniques to synchronously measure the EOD, body position, and posture of a free-swimming WEF for an extended period of time. First, we describe the construction of an experimental tank inside of an isolation chamber designed to block external sources of sensory stimuli such as light, sound, and vibration. The aquarium was partitioned to accommodate four test specimens, and automated gates remotely control the animals' access to the central arena. Second, we describe a precise and reliable real-time EOD timing measurement method from freely swimming WEF. Signal distortions caused by the animal's body movements are corrected by spatial averaging and temporal processing stages. Third, we describe an underwater near-infrared imaging setup to observe unperturbed nocturnal animal behaviors. Infrared light pulses were used to synchronize the timing between the video and the physiological signal over a long recording duration. Our automated tracking software measures the animal's body position and posture reliably in an aquatic scene. In combination, these techniques enable long term observation of spontaneous behavior of freely swimming weakly electric fish in a reliable and precise manner. We believe our method can be similarly applied to the study of other aquatic animals by relating their physiological signals with exploratory or social behaviors. PMID:24637642

  1. Fuel model selection for BEHAVE in midwestern oak savannas

    USGS Publications Warehouse

    Grabner, K.W.; Dwyer, J.P.; Cutter, B.E.

    2001-01-01

    BEHAVE, a fire behavior prediction system, can be a useful tool for managing areas with prescribed fire. However, the proper choice of fuel models can be critical in developing management scenarios. BEHAVE predictions were evaluated using four standardized fuel models that partially described oak savanna fuel conditions: Fuel Model 1 (Short Grass), 2 (Timber and Grass), 3 (Tall Grass), and 9 (Hardwood Litter). Although all four models yielded regressions with R2 in excess of 0.8, Fuel Model 2 produced the most reliable fire behavior predictions.

  2. Differential changes of metabolic brain activity and interregional functional coupling in prefronto-limbic pathways during different stress conditions: functional imaging in freely behaving rodent pups.

    PubMed

    Bock, Jörg; Riedel, Anett; Braun, Katharina

    2012-01-01

    The trumpet-tailed rat or degu (Octodon degus) is an established model to investigate the consequences of early stress on the development of emotional brain circuits and behavior. The aim of this study was to identify brain circuits, that respond to different stress conditions and to test if acute stress alters functional coupling of brain activity among prefrontal and limbic regions. Using functional imaging (2-Fluoro-deoxyglucose method) in 8-day-old male degu pups the following stress conditions were compared: (A) pups together with parents and siblings (control), (B) separation of the litter from the parents, (C) individual separation from parents and siblings, and (D) individual separation and presentation of maternal calls. Condition (B) significantly downregulated brain activity in the prefrontal cortex, hippocampus, nucleus accumbens (NAcc), and sensory areas compared to controls. Activity decrease was even more pronounced during condition (C), where, in contrast to all other regions, activity in the PAG was increased. Interestingly, brain activity in stress-associated brain regions such as the amygdala and habenula was not affected. In condition (D) maternal vocalizations "reactivated" brain activity in the cingulate and precentral medial cortex, NAcc, and striatum and in sensory areas. In contrast, reduced activity was measured in the prelimbic and infralimbic cortex (IL) and in the hippocampus and amygdala. Correlation analysis revealed complex, region- and situation-specific changes of interregional functional coupling among prefrontal and limbic brain regions during stress exposure. We show here for the first time that early life stress results in a widespread reduction of brain activity in the infant brain and changes interregional functional coupling. Moreover, maternal vocalizations can partly buffer stress-induced decrease in brain activity in some regions and evoked very different functional coupling patterns compared to the three other conditions.

  3. Crank inertial load affects freely chosen pedal rate during cycling.

    PubMed

    Hansen, Ernst Albin; Jørgensen, Lars Vincents; Jensen, Kurt; Fregly, Benjamin Jon; Sjøgaard, Gisela

    2002-02-01

    Cyclists seek to maximize performance during competition, and gross efficiency is an important factor affecting performance. Gross efficiency is itself affected by pedal rate. Thus, it is important to understand factors that affect freely chosen pedal rate. Crank inertial load varies greatly during road cycling based on the selected gear ratio. Nevertheless, the possible influence of crank inertial load on freely chosen pedal rate and gross efficiency has never been investigated. This study tested the hypotheses that during cycling with sub-maximal work rates, a considerable increase in crank inertial load would cause (1) freely chosen pedal rate to increase, and as a consequence, (2) gross efficiency to decrease. Furthermore, that it would cause (3) peak crank torque to increase if a constant pedal rate was maintained. Subjects cycled on a treadmill at 150 and 250W, with low and high crank inertial load, and with preset and freely chosen pedal rate. Freely chosen pedal rate was higher at high compared with low crank inertial load. Notably, the change in crank inertial load affected the freely chosen pedal rate as much as did the 100W increase in work rate. Along with freely chosen pedal rate being higher, gross efficiency at 250W was lower during cycling with high compared with low crank inertial load. Peak crank torque was higher during cycling at 90rpm with high compared with low crank inertial load. Possibly, the subjects increased the pedal rate to compensate for the higher peak crank torque accompanying cycling with high compared with low crank inertial load. PMID:11784546

  4. Methylphenidate-induced awake bruxism: a case report.

    PubMed

    Sivri, Rukiye Çolak; Bilgiç, Ayhan

    2015-01-01

    Methylphenidate (MPH) is a stimulant that is commonly used in the treatment of attention-deficit/hyperactivity disorder in children and adults. Several reports are available regarding the relationship of MPH use and sleep bruxism. We report the case of a 9-year-old boy who presented with severe awake bruxism after his second dose of sustained release form of MPH treatment, which was confirmed on rechallenge. This is the first report of its kind showing such relationship in the literature. PMID:25768854

  5. Self-Enhancing in Perceptions of Behaving Unethically.

    ERIC Educational Resources Information Center

    Manley, Gregory G.; Russell, Craig J.; Buckley, M. Ronald

    2001-01-01

    Presented with ethics scenarios, the majority of 43 accounting and 43 marketing majors perceived themselves less likely to behave unethically than others would. Marketing majors showed significantly higher levels of self-enhancement bias, a difference that decreased as perceived risk increased. (SK)

  6. UPPER AIRWAY BLOCKS FOR AWAKE DIFFICULT AIRWAY MANAGEMENT.

    PubMed

    Pintaric, Tatjana Stopar

    2016-03-01

    Airway anesthesia is pivotal for successful awake intubation provided either topically or by blocks. Airway blocks are considered technically more difficult to perform and carry a higher risk of complications. However, in experienced hands, they can be useful as they provide excellent intubating conditions. For complete upper airway anesthesia, bilateral glossopharyngeal and superior laryngeal nerve blocks with translaryngeal injection are required. Superior laryngeal nerve block and translaryngeal injection can be performed easily, safely and with a high success rate in patients with normal anatomy. In those with difficult landmarks, ultrasound can be of assistance. For the superior laryngeal nerve block, other targets than the nerve itself must be established to make the technique consistently successful, easy to teach, learn and perform. The same applies to the translaryngeal injection, where the use of ultrasound is necessary for correct midline identification. Intraoral glossopharyngeal nerve block is also safe and easy to perform, but associated with long lasting discomfort. Bilateral extraoral peristyloid approach should be discouraged since inadvertent blocks of the closely adjacent vagus nerve cannot be prevented in this location. A safe and easy method of blocking the distal portions of the glossopharyngeal nerve for awake intubation is therefore required. PMID:27276778

  7. Realignment strategies for awake-monkey fMRI data.

    PubMed

    Stoewer, Steffen; Goense, Jozien; Keliris, Georgios A; Bartels, Andreas; Logothetis, Nikos K; Duncan, John; Sigala, Natasha

    2011-12-01

    Functional magnetic resonance imaging (fMRI) experiments with awake nonhuman primates (NHPs) have recently seen a surge of applications. However, the standard fMRI analysis tools designed for human experiments are not optimal for NHP data collected at high fields. One major difference is the experimental setup. Although real head movement is impossible for NHPs, MRI image series often contain visible motion artifacts. Animal body movement results in image position changes and geometric distortions. Since conventional realignment methods are not appropriate to address such differences, algorithms tailored specifically for animal scanning become essential. We have implemented a series of high-field NHP specific methods in a software toolbox, fMRI Sandbox (http://kyb.tuebingen.mpg.de/~stoewer/), which allows us to use different realignment strategies. Here we demonstrate the effect of different realignment strategies on the analysis of awake-monkey fMRI data acquired at high field (7 T). We show that the advantage of using a nonstandard realignment algorithm depends on the amount of distortion in the dataset. While the benefits for less distorted datasets are minor, the improvement of statistical maps for heavily distorted datasets is significant.

  8. Intrinsic Feature Pose Measurement for Awake Animal SPECT Imaging

    SciTech Connect

    Goddard Jr, James Samuel; Baba, Justin S; Lee, Seung Joon; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    New developments have been made in optical motion tracking for awake animal imaging that measures 3D position and orientation (pose) for a single photon emission computed tomography (SPECT) imaging system. Ongoing SPECT imaging research has been directed towards head motion measurement for brain studies in awake, unrestrained mice. In contrast to previous results using external markers, this work extracts and tracks intrinsic features from multiple camera images and computes relative pose from the tracked features over time. Motion tracking thus far has been limited to measuring extrinsic features such as retro-reflective markers applied to the mouse s head. While this approach has been proven to be accurate, the additional animal handling required to attach the markers is undesirable. A significant improvement in the procedure is achieved by measuring the pose of the head without extrinsic markers using only the external surface appearance. This approach is currently being developed with initial results presented here. The intrinsic features measurement extracts discrete, sparse natural features from 2D images such as eyes, nose, mouth and other visible structures. Stereo correspondence between features for a camera pair is determined for calculation of 3D positions. These features are also tracked over time to provide continuity for surface model fitting. Experimental results from live images are presented.

  9. Ventilation and respiratory pattern and timing in resting awake cats.

    PubMed

    Jennings, D B; Szlyk, P C

    1985-02-01

    The purpose of this study was to characterize the variability and patterns of spontaneous respiratory behaviour in awake cats. Respiration was measured in six cats over 80 or 90 min by the plethysmographic technique. In three cats, arterial blood gases were measured. Breath frequency (f) and tidal volume (VT) varied considerably breath-to-breath, although on average, these measurements as well as average ventilation remained relatively constant. The incidence of breath ventilation (VT X 60/TTOT) and VT were distributed unimodally but the incidence of breath f had a bimodal distribution. In the low f range, average f was 22.5 breaths/min, and in the high f range, average f was 41.6 breaths/min. The latter range appeared to be associated with purring. Inspiratory duration (TI) was less than expiratory duration (TE) at low f but exceeded TE at high f. For a given breath ventilation there was a predictable f and VT. At shorter TI (higher f) mean inspiratory flow, an index of central respiratory drive, increased but VT decreased. This study indicates that "normal" control respiratory behaviour in awake cats is better described by the range and pattern of breathing than by average values.

  10. Mapping oxygen concentration in the awake mouse brain

    PubMed Central

    Lyons, Declan G; Parpaleix, Alexandre; Roche, Morgane; Charpak, Serge

    2016-01-01

    Although critical for brain function, the physiological values of cerebral oxygen concentration have remained elusive because high-resolution measurements have only been performed during anesthesia, which affects two major parameters modulating tissue oxygenation: neuronal activity and blood flow. Using measurements of capillary erythrocyte-associated transients, fluctuations of oxygen partial pressure (Po2) associated with individual erythrocytes, to infer Po2 in the nearby neuropil, we report the first non-invasive micron-scale mapping of cerebral Po2 in awake, resting mice. Interstitial Po2 has similar values in the olfactory bulb glomerular layer and the somatosensory cortex, whereas there are large capillary hematocrit and erythrocyte flux differences. Awake tissue Po2 is about half that under isoflurane anesthesia, and within the cortex, vascular and interstitial Po2 values display layer-specific differences which dramatically contrast with those recorded under anesthesia. Our findings emphasize the importance of measuring energy parameters non-invasively in physiological conditions to precisely quantify and model brain metabolism. DOI: http://dx.doi.org/10.7554/eLife.12024.001 PMID:26836304

  11. Energy Decay in Three-Dimensional Freely Cooling Granular Gas

    NASA Astrophysics Data System (ADS)

    Pathak, Sudhir N.; Jabeen, Zahera; Das, Dibyendu; Rajesh, R.

    2014-01-01

    The kinetic energy of a freely cooling granular gas decreases as a power law t-θ at large times t. Two theoretical conjectures exist for the exponent θ. One based on ballistic aggregation of compact spherical aggregates predicts θ =2d/(d+2) in d dimensions. The other based on Burgers equation describing anisotropic, extended clusters predicts θ =d/2 when 2≤d≤4. We do extensive simulations in three dimensions to find that while θ is as predicted by ballistic aggregation, the cluster statistics and velocity distribution differ from it. Thus, the freely cooling granular gas fits to neither the ballistic aggregation or a Burgers equation description.

  12. Single-molecule diffusion in freely suspended smectic films.

    PubMed

    Schulz, Benjamin; Mazza, Marco G; Bahr, Christian

    2014-10-01

    We present a study of the molecular diffusion in freely suspended smectic-A liquid crystal films with thicknesses ranging from 20 down to only two molecular layers. The molecular mobility is directly probed by determining the trajectories of single, fluorescent tracer molecules. We demonstrate, using several different smectic compounds, that a monotonic increase of the diffusion coefficient with decreasing film thickness is a general phenomenon. In two-layer films, the diffusion is enhanced by a factor of 3 to 5 compared to the corresponding bulk smectic phase. Molecular dynamics simulations of freely suspended smectic films are presented which support the experimental results.

  13. Anticipating and Resisting the Temptation to Behave Unethically.

    PubMed

    Sheldon, Oliver J; Fishbach, Ayelet

    2015-07-01

    Ethical dilemmas pose a self-control conflict between pursuing immediate benefits through behaving dishonestly and pursuing long-term benefits through acts of honesty. Therefore, factors that facilitate self-control for other types of goals (e.g., health and financial) should also promote ethical behavior. Across four studies, we find support for this possibility. Specifically, we find that only under conditions that facilitate conflict identification--including the consideration of several decisions simultaneously (i.e., a broad decision frame) and perceived high connectedness to the future self--does anticipating a temptation to behave dishonestly in advance promote honesty. We demonstrate these interaction patterns between conflict identification and temptation anticipation in negotiation situations (Study 1), lab tasks (Study 2), and ethical dilemmas in the workplace (Studies 3-4). We conclude that identifying a self-control conflict and anticipating a temptation are two necessary preconditions for ethical decision making. PMID:26001580

  14. Wearable scanning photoacoustic brain imaging in behaving rats.

    PubMed

    Tang, Jianbo; Dai, Xianjin; Jiang, Huabei

    2016-06-01

    A wearable scanning photoacoustic imaging (wPAI) system is presented for noninvasive brain study in behaving rats. This miniaturized wPAI system consists of four pico linear servos and a single transducer-based PAI probe. It has a dimension of 50 mm × 35 mm × 40 mm, and a weight of 26 g excluding cablings. Phantom evaluation shows that wPAI achieves a lateral resolution of ∼0.5 mm and an axial resolution of ∼0.1 mm at a depth of up to 11 mm. Its imaging ability is also tested in a behaving rat, and the results indicate that wPAI is able to image blood vessels at a depth of up to 5 mm with intact scalp and skull. With its noninvasive, deep penetration, and functional imaging ability in behaving animals, wPAI can be used for behavior, cognition, and preclinical brain disease studies. PMID:26777064

  15. Wireless multi-channel single unit recording in freely moving and vocalizing primates.

    PubMed

    Roy, Sabyasachi; Wang, Xiaoqin

    2012-01-15

    The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates.

  16. Wireless multi-channel single unit recording in freely moving and vocalizing primates

    PubMed Central

    Roy, Sabyasachi; Wang, Xiaoqin

    2011-01-01

    The ability to record well-isolated action potentials from individual neurons in naturally behaving animals is crucial for understanding neural mechanisms underlying natural behaviors. Traditional neurophysiology techniques, however, require the animal to be restrained which often restricts natural behavior. An example is the common marmoset (Callithrix jacchus), a highly vocal New World primate species, used in our laboratory to study the neural correlates of vocal production and sensory feedback. When restrained by traditional neurophysiological techniques marmoset vocal behavior is severely inhibited. Tethered recording systems, while proven effective in rodents pose limitations in arboreal animals such as the marmoset that typically roam in a three-dimensional environment. To overcome these obstacles, we have developed a wireless neural recording technique that is capable of collecting single-unit data from chronically implanted multi-electrodes in freely moving marmosets. A lightweight, low power and low noise wireless transmitter (headstage) is attached to a multi-electrode array placed in the premotor cortex of the marmoset. The wireless headstage is capable of transmitting 15 channels of neural data with signal-to-noise ratio (SNR) comparable to a tethered system. To minimize radio-frequency (RF) and electro-magnetic interference (EMI), the experiments were conducted within a custom designed RF/EMI and acoustically shielded chamber. The individual electrodes of the multi-electrode array were periodically advanced to densely sample the cortical layers. We recorded single-unit data over a period of several months from the frontal cortex of two marmosets. These recordings demonstrate the feasibility of using our wireless recording method to study single neuron activity in freely roaming primates. PMID:21933683

  17. Spike timing and synaptic dynamics at the awake thalamocortical synapse.

    PubMed

    Swadlow, Harvey A; Bezdudnaya, Tatiana; Gusev, Alexander G

    2005-01-01

    Thalamocortical (TC) neurons form only a small percentage of the synapses onto neurons of cortical layer 4, but the response properties of these cortical neurons are arguably dominated by thalamic input. This discrepancy is explained, in part, by studies showing that TC synapses are of high efficacy. However, TC synapses display activity-dependent depression. Because of this, in vitro measures of synaptic efficacy will not reflect the situation in vivo, where different neuronal populations have widely varying levels of "spontaneous" activity. Indeed, TC neurons of awake subjects generate high rates of spontaneous activity that would be expected, in a depressing synapse, to result in a chronic state of synaptic depression. Here, we review recent work in the somatosensory thalamocortical system of awake rabbits in which the relationship between TC spike timing and TC synaptic efficacy was examined during both thalamic "relay mode" (alert state) and "burst mode" (drowsy state). Two largely independent methodological approaches were used. First, we employed cross-correlation methods to examine the synaptic impact of single TC "barreloid" neurons on a single neuronal subtype in the topographically aligned layer 4 "barrel" - putative fast-spike inhibitory interneurons. We found that the initial spike of a TC burst, as well as isolated TC spikes with long preceding interspike intervals (ISIs) elicited postsynaptic action potentials far more effectively than did TC impulses with short ISIs. Our second approach took a broader view of the postsynaptic impact of TC impulses. In these experiments we examined spike-triggered extracellular field potentials and synaptic currents (using current source-density analysis) generated through the depths of a cortical barrel column by the impulses of single topographically aligned TC neurons. We found that (a) closely neighboring TC neurons may elicit very different patterns of monosynaptic activation within layers 4 and 6 of the aligned

  18. Long-term Potentiation at Temporoammonic Path-CA1 Synapses in Freely Moving Rats

    PubMed Central

    Gonzalez, Jossina; Villarreal, Desiree M.; Morales, Isaiah S.; Derrick, Brian E.

    2016-01-01

    Hippocampal area CA1 receives direct entorhinal layer III input via the temporoammonic path (TAP) and recent studies implicate TAP-CA1 synapses are important for some aspects of hippocampal memory function. Nonetheless, as few studies have examined TAP-CA1 synaptic plasticity in vivo, the induction and longevity of TAP-CA1 long-term potentiation (LTP) has not been fully characterized. We analyzed CA1 responses following stimulation of the medial aspect of the angular bundle and investigated LTP at medial temporoammonic path (mTAP)-CA1 synapses in freely moving rats. We demonstrate monosynaptic mTAP-CA1 responses can be isolated in vivo as evidenced by observations of independent current sinks in the stratum lacunosum moleculare of both areas CA1 and CA3 following angular bundle stimulation. Contrasting prior indications that TAP input rarely elicits CA1 discharge, we observed mTAP-CA1 responses that appeared to contain putative population spikes in 40% of our behaving animals. Theta burst high frequency stimulation of mTAP afferents resulted in an input specific and N-methyl-D-aspartate (NMDA) receptor-dependent LTP of mTAP-CA1 responses in behaving animals. LTP of mTAP-CA1 responses decayed as a function of two exponential decay curves with time constants (τ) of 2.7 and 148 days to decay 63.2% of maximal LTP. In contrast, mTAP-CA1 population spike potentiation longevity demonstrated a τ of 9.6 days. To our knowledge, these studies provide the first description of mTAP-CA1 LTP longevity in vivo. These data indicate TAP input to area CA1 is a physiologically relevant afferent system that displays robust synaptic plasticity. PMID:26903815

  19. Sleep bruxism, awake bruxism and sleep quality among Brazilian dental students: a cross-sectional study.

    PubMed

    Serra-Negra, Júnia Maria; Scarpelli, Ana Carolina; Tirsa-Costa, Débora; Guimarães, Flávia Helena; Pordeus, Isabela Almeida; Paiva, Saul Martins

    2014-01-01

    The aim of the study was to evaluate the association of sleep bruxism, awake bruxism and sleep quality among dental students of the Federal University of Minas Gerais, Belo Horizonte, Brazil. A cross-sectional study was performed including 183 Brazilian dental students aged from 17 to 46 years old. The complete course curriculum consists of 9 semesters. Students enrolled in the first semester, the middle semester and the final semester of the course participated in the survey. The PSQI-BR (the Brazilian version of the Pittsburgh Sleep Questionnaire Index) was used for data collection. The PSQI-BR was distributed during lecture classes. Sleep bruxism and awake bruxism diagnosis was based on self-reported data. Descriptive analysis, Kruskal-Wallis, Mann-Whitney and Poisson regression with robust estimator were the statistical tests used. Sleep bruxism prevalence was 21.5% and awake bruxism prevalence was 36.5%. Sleep duration components were associated with sleep bruxism (PR=1.540; 95% CI: 1.00-2.37) and awake bruxism (PR=1.344; 95% CI: 1,008-1,790). There was an association between awake bruxism and habitual sleep efficiency component (PR=1.323; 95% CI: 1.03-1.70). Sleep disturbance component and awake bruxism were associated (PR=1.533; 95% CI: 1.03-2.27). Poor sleep quality was an important factor among dental students, who reported sleep bruxism as well as among those who presented awake bruxism.

  20. The electron accelerator for the AWAKE experiment at CERN

    NASA Astrophysics Data System (ADS)

    Pepitone, K.; Doebert, S.; Burt, G.; Chevallay, E.; Chritin, N.; Delory, C.; Fedosseev, V.; Hessler, Ch.; McMonagle, G.; Mete, O.; Verzilov, V.; Apsimon, R.

    2016-09-01

    The AWAKE collaboration prepares a proton driven plasma wakefield acceleration experiment using the SPS beam at CERN. A long proton bunch extracted from the SPS interacts with a high power laser and a 10 m long rubidium vapour plasma cell to create strong wakefields allowing sustained electron acceleration. The electron bunch to probe these wakefields is supplied by a 20 MeV electron accelerator. The electron accelerator consists of an RF-gun and a short booster structure. This electron source should provide beams with intensities between 0.1 and 1 nC, bunch lengths between 0.3 and 3 ps and an emittance of the order of 2 mm mrad. The wide range of parameters should cope with the uncertainties and future prospects of the planned experiments. The layout of the electron accelerator, its instrumentation and beam dynamics simulations are presented.

  1. Awake hippocampal reactivations project onto orthogonal neuronal assemblies.

    PubMed

    Malvache, Arnaud; Reichinnek, Susanne; Villette, Vincent; Haimerl, Caroline; Cossart, Rosa

    2016-09-16

    The chained activation of neuronal assemblies is thought to support major cognitive processes, including memory. In the hippocampus, this is observed during population bursts often associated with sharp-wave ripples, in the form of an ordered reactivation of neurons. However, the organization and lifetime of these assemblies remain unknown. We used calcium imaging to map patterns of synchronous neuronal activation in the CA1 region of awake mice during runs on a treadmill. The patterns were composed of the recurring activation of anatomically intermingled, but functionally orthogonal, assemblies. These assemblies reactivated discrete temporal segments of neuronal sequences observed during runs and could be stable across consecutive days. A binding of these assemblies into longer chains revealed temporally ordered replay. These modules may represent the default building blocks for encoding or retrieving experience. PMID:27634534

  2. Awake hippocampal reactivations project onto orthogonal neuronal assemblies.

    PubMed

    Malvache, Arnaud; Reichinnek, Susanne; Villette, Vincent; Haimerl, Caroline; Cossart, Rosa

    2016-09-16

    The chained activation of neuronal assemblies is thought to support major cognitive processes, including memory. In the hippocampus, this is observed during population bursts often associated with sharp-wave ripples, in the form of an ordered reactivation of neurons. However, the organization and lifetime of these assemblies remain unknown. We used calcium imaging to map patterns of synchronous neuronal activation in the CA1 region of awake mice during runs on a treadmill. The patterns were composed of the recurring activation of anatomically intermingled, but functionally orthogonal, assemblies. These assemblies reactivated discrete temporal segments of neuronal sequences observed during runs and could be stable across consecutive days. A binding of these assemblies into longer chains revealed temporally ordered replay. These modules may represent the default building blocks for encoding or retrieving experience.

  3. Default-mode-like network activation in awake rodents.

    PubMed

    Upadhyay, Jaymin; Baker, Scott J; Chandran, Prasant; Miller, Loan; Lee, Younglim; Marek, Gerard J; Sakoglu, Unal; Chin, Chih-Liang; Luo, Feng; Fox, Gerard B; Day, Mark

    2011-01-01

    During wakefulness and in absence of performing tasks or sensory processing, the default-mode network (DMN), an intrinsic central nervous system (CNS) network, is in an active state. Non-human primate and human CNS imaging studies have identified the DMN in these two species. Clinical imaging studies have shown that the pattern of activity within the DMN is often modulated in various disease states (e.g., Alzheimer's, schizophrenia or chronic pain). However, whether the DMN exists in awake rodents has not been characterized. The current data provides evidence that awake rodents also possess 'DMN-like' functional connectivity, but only subsequent to habituation to what is initially a novel magnetic resonance imaging (MRI) environment as well as physical restraint. Specifically, the habituation process spanned across four separate scanning sessions (Day 2, 4, 6 and 8). At Day 8, significant (p<0.05) functional connectivity was observed amongst structures such as the anterior cingulate (seed region), retrosplenial, parietal, and hippocampal cortices. Prior to habituation (Day 2), functional connectivity was only detected (p<0.05) amongst CNS structures known to mediate anxiety (i.e., anterior cingulate (seed region), posterior hypothalamic area, amygdala and parabracial nucleus). In relating functional connectivity between cingulate-default-mode and cingulate-anxiety structures across Days 2-8, a significant inverse relationship (r = -0.65, p = 0.0004) was observed between these two functional interactions such that increased cingulate-DMN connectivity corresponded to decreased cingulate anxiety network connectivity. This investigation demonstrates that the cingulate is an important component of both the rodent DMN-like and anxiety networks.

  4. Effects of memantine on hippocampal long-term potentiation, gamma activity, and sensorimotor gating in freely moving rats.

    PubMed

    Ma, Jingyi; Mufti, Asfandyar; Stan Leung, L

    2015-09-01

    Memantine, an uncompetitive N-methyl-D-aspartate receptor antagonist, is used for treatment of patients with Alzheimer's disease. The mechanisms of memantine in relieving cognitive and behavioral symptoms are unclear, and this study attempts to elucidate its action on network and synaptic functions of the hippocampus. The effects of memantine on electrographic activity and hippocampal long-term potentiation (LTP) were investigated in freely moving rats. Basal dendritic excitation on hippocampal CA1 pyramidal cells showed a robust LTP after theta-frequency primed bursts, and the LTP was higher after 5-10 mg/kg intraperitoneal (ip) memantine pretreatment, as compared with saline pretreatment. Injection of scopolamine (5 mg/kg ip) before memantine failed to block the LTP-enhancing effect of memantine. Memantine as compared with saline pretreatment did not affect the LTP after an afterdischarge induced by high-frequency (200-Hz) train stimulation. Memantine (5 or 10 mg/kg ip) significantly enhanced gamma oscillations in the hippocampal local field potentials of 40-100 Hz during walking and awake immobility. Memantine at 10 mg/kg ip, but not at 5 mg/kg ip, increased prepulse inhibition of the acoustic startle response, while both 5 and 10 mg/kg ip memantine enhanced the acoustic startle response as compared with saline-injected rats. These electrophysiological and behavioral effects of memantine are unique among N-methyl-D-aspartate receptor antagonists but are consistent with memantine's effects in improving cognitive and sensorimotor functions of Alzheimer's patients.

  5. The effects of systemically administered taurine and N-pivaloyltaurine on striatal extracellular dopamine and taurine in freely moving rats.

    PubMed

    Salimäki, J; Scriba, G; Piepponen, T P; Rautolahti, N; Ahtee, L

    2003-08-01

    The second most abundant cerebral amino acid, taurine, is widely consumed in the so-called "energy drinks". Therefore, its possible actions on the brain are of great interest. In the present experiments taurine was given intraperitoneally to rats in order to study if it can be administered systemically in large enough amounts to alter cerebral dopaminergic transmission or to induce hypothermia. In addition, the effects of subcutaneously administered lipophilic taurine analogue, N-pivaloyltaurine, were studied. The extracellular striatal taurine and dopamine concentrations were estimated using in vivo microdialysis in awake and freely moving rats, and the rectal temperatures were measured. Taurine at the total dose of 45 mmol/kg i.p. led to a maximally 8-fold increased striatal extracellular taurine concentration, induced a long-lasting hypothermia, and significantly reduced the striatal extracellular dopamine concentration. The latter effect was strengthened by co-treatment with reuptake inhibitor nomifensine. N-pivaloyltaurine (15 mmol/kg in total, s.c.) only slightly elevated the striatal extracellular taurine concentration, failed to alter the rectal temperature, and in contrast to taurine somewhat elevated the striatal extracellular dopamine concentration suggesting a different mechanism or locus of action from that of taurine. Finally, our experiments using brain microdialysis confirmed the earlier findings that taurine is slowly eliminated from the brain. The results clearly indicate that systemically given taurine enters the brain in concentrations that induce pharmacological effects. PMID:12898127

  6. Mini-coil for magnetic stimulation in the behaving primate.

    PubMed

    Tischler, Hadass; Wolfus, Shuki; Friedman, Alexander; Perel, Eli; Pashut, Tamar; Lavidor, Michal; Korngreen, Alon; Yeshurun, Yosef; Bar-Gad, Izhar

    2011-01-15

    Transcranial magnetic stimulation (TMS) is rapidly becoming a leading method in both cognitive neuroscience and clinical neurology. However, the cellular and network level effects of stimulation are still unclear and their study relies heavily on indirect physiological measurements in humans. Direct electrophysiological studies of the effect of magnetic stimulation on neuronal activity in behaving animals are severely limited by both the size of the stimulating coils, which affect large regions of the animal brain, and the large artifacts generated on the recording electrodes. We present a novel mini-coil which is specifically aimed at studying the neurophysiological mechanism of magnetic stimulation in behaving primates. The mini-coil fits into a chronic recording chamber and provides focal activation of brain areas while enabling simultaneous extracellular multi-electrode recordings. We present a comparison of this coil to a commercial coil based on the theoretical and recorded magnetic fields and induced electric fields they generate. Subsequently, we present the signal recorded in the behaving primate during stimulation and demonstrate the ability to extract the spike trains of multiple single units from each of the electrodes with minimal periods affected by the stimulus artifact (median period <2.5 ms). The directly recorded effect of the magnetic stimulation on cortical neurons is in line with peripheral recordings obtained in humans. This novel mini-coil is a key part of the infrastructure for studying the neurophysiological basis of magnetic stimulation, thereby enabling the development and testing of better magnetic stimulation tools and protocols for both neuroscientists and clinicians. PMID:20974177

  7. Neutral atoms behave much like classical spherical capacitors

    SciTech Connect

    Ellenbogen, James C.

    2006-09-15

    The scaling of the capacitance with radius is explored in detail for neutral atoms, and it is found that they behave much like macroscopic spherical capacitors. The quantum capacitances of atoms scale as a linear function of the mean radii of their highest occupied orbitals. The slopes of the linear scaling lines include a dimensionless constant of proportionality {kappa} that is somewhat analogous to a dielectric constant, but for individual atoms. The slope and {kappa} assume discrete values characteristic of elements in different regions of the periodic table. These observations provide a different, electrostatics-based way of understanding the periodic behavior of the elements.

  8. A Magnetic Rotary Optical Fiber Connector for Optogenetic Experiments in Freely Moving Animals

    PubMed Central

    Klorig, David C; Godwin, Dwayne W

    2014-01-01

    Background Performing optogenetic experiments in a behaving animal presents a unique technical challenge. In order to provide an optical path between a fixed light source and a chronically implanted fiber in a freely moving animal, a typical experimental set-up includes a detachable connection between the light source and the head of the animal, as well as a rotary joint to relieve torsional stress during movement. New Method We have combined the functionality of the head mounted connector and the rotary joint into a single integrated device that is inexpensive, simple to build and easy to use. Results A typical rotary connector has a transmission efficiency of 80% with a rotational variability of 4%, but can be configured to have a rotational variability of 2% at the expense of lower transmission efficiency. Depending on configuration, rotational torque ranges from 14 - 180 μN*m, making the rotary connector suitable for use with small animals such as mice. Comparison with Existing Methods Benchmark tests demonstrate that our connectors perform similarly to commercially available solutions in terms of transmission efficiency, rotational variability, and torque but at a fraction of the cost. Unlike currently available solutions, our unique design requires a single optical junction which significantly reduces overall light loss. In addition, magnets allow the connectors and caps to “snap into place” for quick yet reliable connection and disconnection. Conclusions Our rotary connector system offers superior performance, reduced cost, and is easily incorporated into existing optogenetic set-ups. PMID:24613796

  9. Flyception: imaging brain activity in freely walking fruit flies.

    PubMed

    Grover, Dhruv; Katsuki, Takeo; Greenspan, Ralph J

    2016-07-01

    Genetically encoded calcium sensors have enabled monitoring of neural activity in vivo using optical imaging techniques. Linking neural activity to complex behavior remains challenging, however, as most imaging systems require tethering the animal, which can impact the animal's behavioral repertoire. Here, we report a method for monitoring the brain activity of untethered, freely walking Drosophila melanogaster during sensorially and socially evoked behaviors to facilitate the study of neural mechanisms that underlie naturalistic behaviors. PMID:27183441

  10. Calcium imaging with genetically encoded indicators in behaving primates

    PubMed Central

    Seidemann, Eyal; Chen, Yuzhi; Bai, Yoon; Chen, Spencer C; Mehta, Preeti; Kajs, Bridget L; Geisler, Wilson S; Zemelman, Boris V

    2016-01-01

    Understanding the neural basis of behaviour requires studying brain activity in behaving subjects using complementary techniques that measure neural responses at multiple spatial scales, and developing computational tools for understanding the mapping between these measurements. Here we report the first results of widefield imaging of genetically encoded calcium indicator (GCaMP6f) signals from V1 of behaving macaques. This technique provides a robust readout of visual population responses at the columnar scale over multiple mm2 and over several months. To determine the quantitative relation between the widefield GCaMP signals and the locally pooled spiking activity, we developed a computational model that sums the responses of V1 neurons characterized by prior single unit measurements. The measured tuning properties of the GCaMP signals to stimulus contrast, orientation and spatial position closely match the predictions of the model, suggesting that widefield GCaMP signals are linearly related to the summed local spiking activity. DOI: http://dx.doi.org/10.7554/eLife.16178.001 PMID:27441501

  11. Soot Formation in Freely-Propagating Laminar Premixed Flames

    NASA Technical Reports Server (NTRS)

    Lin, K.-C.; Hassan, M. I.; Faeth, G. M.

    1997-01-01

    Soot formation within hydrocarbon-fueled flames is an important unresolved problem of combustion science. Thus, the present study is considering soot formation in freely-propagating laminar premixed flames, exploiting the microgravity environment to simplify measurements at the high-pressure conditions of interest for many practical applications. The findings of the investigation are relevant to reducing emissions of soot and continuum radiation from combustion processes, to improving terrestrial and spacecraft fire safety, and to developing methods of computational combustion, among others. Laminar premixed flames are attractive for studying soot formation because they are simple one-dimensional flows that are computationally tractable for detailed numerical simulations. Nevertheless, studying soot-containing burner-stabilized laminar premixed flames is problematical: spatial resolution and residence times are limited at the pressures of interest for practical applications, flame structure is sensitive to minor burner construction details so that experimental reproducibility is not very good, consistent burner behavior over the lengthy test programs needed to measure soot formation properties is hard to achieve, and burners have poor durability. Fortunately, many of these problems are mitigated for soot-containing, freely-propagating laminar premixed flames. The present investigation seeks to extend work in this laboratory for various soot processes in flames by observing soot formation in freely-propagating laminar premixed flames. Measurements are being made at both Normal Gravity (NG) and MicroGravity (MG), using a short-drop free-fall facility to provide MG conditions.

  12. Pediatric awake craniotomy for seizure focus resection with dexmedetomidine sedation-a case report.

    PubMed

    Sheshadri, Veena; Chandramouli, B A

    2016-08-01

    Resection of lesions near the eloquent cortex of brain necessitates awake craniotomy to reduce the risk of permanent neurologic deficits during surgery. There are limited reports of anesthetic management of awake craniotomy in pediatric patients. This report is on use of dexmedetomidine sedation for awake craniotomy in a 11-year-old child, without any airway adjuncts throughout the procedure. Dexmedetomidine infusion administered at a dosage of 0.2 to 0.7μg kg(-1) h(-1) provided adequate sedation for the entire procedure. There were no untoward incidents or any interference with electrocorticography, intraoperative stimulation, and functional mapping. Adequate preoperative visits and counseling of patient and parents regarding course and nature of events along with well-planned intraoperative management are of utmost importance in a pediatric age group for successful intraoperative awake craniotomy. PMID:27290976

  13. Pediatric awake craniotomy for seizure focus resection with dexmedetomidine sedation-a case report.

    PubMed

    Sheshadri, Veena; Chandramouli, B A

    2016-08-01

    Resection of lesions near the eloquent cortex of brain necessitates awake craniotomy to reduce the risk of permanent neurologic deficits during surgery. There are limited reports of anesthetic management of awake craniotomy in pediatric patients. This report is on use of dexmedetomidine sedation for awake craniotomy in a 11-year-old child, without any airway adjuncts throughout the procedure. Dexmedetomidine infusion administered at a dosage of 0.2 to 0.7μg kg(-1) h(-1) provided adequate sedation for the entire procedure. There were no untoward incidents or any interference with electrocorticography, intraoperative stimulation, and functional mapping. Adequate preoperative visits and counseling of patient and parents regarding course and nature of events along with well-planned intraoperative management are of utmost importance in a pediatric age group for successful intraoperative awake craniotomy.

  14. Chronic multiscale imaging of neuronal activity in the awake common marmoset

    PubMed Central

    Yamada, Yoshiyuki; Matsumoto, Yoshifumi; Okahara, Norio; Mikoshiba, Katsuhiko

    2016-01-01

    We report a methodology to chronically record in vivo brain activity in the awake common marmoset. Over a month, stable imaging revealed macroscopic sensory maps in the somatosensory cortex and their underlying cellular activity with a high signal-to-noise ratio in the awake but not anesthetized state. This methodology is applicable to other brain regions, and will be useful for studying cortical activity and plasticity in marmosets during learning, development, and in neurological disorders. PMID:27786241

  15. Language testing during awake "anesthesia" in a bilingual patient with brain lesion adjacent to Wernicke's area.

    PubMed

    Bilotta, Federico; Stazi, Elisabetta; Delfini, Roberto; Rosa, Giovanni

    2011-04-01

    Awake "anesthesia" is the preferable anesthetic approach for neurosurgical procedures that require intraoperative localization of eloquent brain areas. We describe intraoperative inducible selective English aphasia in a bilingual (English and Italian) patient undergoing awake anesthesia for excision of a brain lesion adjacent to Wernicke's area with no postoperative neurological sequelae. We discuss the importance of intraoperative brain mapping and intraoperative language testing in bilingual patients to prevent iatrogenic-related morbidity.

  16. The efficacy of combined regional nerve blocks in awake orotracheal fiberoptic intubation

    PubMed Central

    Chatrath, Veena; Sharan, Radhe; Jain, Payal; Bala, Anju; Ranjana; Sudha

    2016-01-01

    Aims of Study: To evaluate the efficacy, hemodynamic changes, and patient comfort during awake fiberoptic intubation done under combined regional blocks. Materials and Methods: In the present observational study, 50 patients of American Society of Anesthesiologists ( ASA) Grade I–II, Mallampati Grade I–IV were given nerve blocks - bilateral glossopharyngeal nerve block, bilateral superior laryngeal nerve block, and recurrent laryngeal nerve block before awake fiberoptic intubation using 2% lidocaine. Results: Procedure was associated with minimal increases in hemodynamic parameters during the procedure and until 3 min after it. Most of the intubations were being carried out within 3 min. Patient comfort was satisfactory with 90% of patients having favorable grades. Discussion: The most common cause of mortality and serious morbidity due to anesthesia is from airway problems. One-third of all anesthetic deaths are due to failure to intubate and ventilate. Awake flexible fiberoptic intubation under local anesthesia is now an accepted technique for managing such situations. In awake patient's anatomy, muscle tone, airway protection, and ventilation are preserved, but it is essential to sufficiently anesthetize the upper airway before the performance of awake fiberoptic bronchoscope-guided intubation to ensure patient comfort and cooperation for which in our study we used the nerve block technique. Conclusion: A properly performed technique of awake fiberoptic intubation done under combined regional nerve blocks provides good intubating conditions, patient comfort and safety and results in minimal hemodynamic changes. PMID:27212757

  17. Intranasal Administration of CNS Therapeutics to Awake Mice

    PubMed Central

    Hanson, Leah R.; Fine, Jared M.; Svitak, Aleta L.; Faltesek, Katherine A.

    2013-01-01

    Intranasal administration is a method of delivering therapeutic agents to the central nervous system (CNS). It is non-invasive and allows large molecules that do not cross the blood-brain barrier access to the CNS. Drugs are directly targeted to the CNS with intranasal delivery, reducing systemic exposure and thus unwanted systemic side effects1. Delivery from the nose to the CNS occurs within minutes along both the olfactory and trigeminal neural pathways via an extracellular route and does not require drug to bind to any receptor or axonal transport2. Intranasal delivery is a widely publicized method and is currently being used in human clinical trials3. Intranasal delivery of drugs in animal models allows for initial evaluation of pharmacokinetic distribution and efficacy. With mice, it is possible to administer drugs to awake (non-anesthetized) animals on a regular basis using a specialized intranasal grip. Awake delivery is beneficial because it allows for long-term chronic dosing without anesthesia, it takes less time than with anesthesia, and can be learned and done by many people so that teams of technicians can dose large numbers of mice in short periods. Efficacy of therapeutics administered intranasally in this way to mice has been demonstrated in a number of studies including insulin in diabetic mouse models 4-6 and deferoxamine in Alzheimer's mouse models. 7,8 The intranasal grip for mice can be learned, but is not easy and requires practice, skill, and a precise grip to effectively deliver drug to the brain and avoid drainage to the lung and stomach. Mice are restrained by hand using a modified scruff in the non-dominant hand with the neck held parallel to the floor, while drug is delivered with a pipettor using the dominant hand. It usually takes 3-4 weeks of acclimating to handling before mice can be held with this grip without a stress response. We have prepared this JoVE video to make this intranasal delivery technique more accessible. PMID

  18. Behaving as or behaving as if? Children's conceptions of personified robots and the emergence of a new ontological category.

    PubMed

    Severson, Rachel L; Carlson, Stephanie M

    2010-01-01

    Imagining another's perspective is an achievement in social cognition and underlies empathic concern and moral regard. Imagination is also within the realm of fantasy, and may take the form of imaginary play in children and imaginative production in adults. Yet, an interesting and provocative question emerges in the case of personified robots: How do people conceive of life-like robots? Do people imagine about robots' experiences? If so, do these imaginings reflect their actual or pretend beliefs about robots? The answers to these questions bear on the possibility that personified robots represent the emergence of a new ontological category. We draw on simulation theory as a framework for imagining others' internal states as well as a means for imaginative play. We then turn to the literature on people's and, in particular, children's conceptions of personified technologies and raise the question of the veracity of children's beliefs about personified robots (i.e., are they behaving as or behaving as if?). Finally, we consider the suggestion that such personified technologies represent the emergence of a new ontological category and offer some suggestions for future research in this important emerging area of social cognition.

  19. Well behaved anisotropic compact star models in general relativity

    NASA Astrophysics Data System (ADS)

    Jasim, M. K.; Maurya, S. K.; Gupta, Y. K.; Dayanandan, B.

    2016-11-01

    Anisotropic compact star models have been constructed by assuming a particular form of a metric function e^{λ}. We solved the Einstein field equations for determining the metric function e^{ν}. For this purpose we have assumed a physically valid expression of radial pressure (pr). The obtained anisotropic compact star model is representing the realistic compact objects such as PSR 1937 +21. We have done an extensive study about physical parameters for anisotropic models and found that these parameters are well behaved throughout inside the star. Along with these we have also determined the equation of state for compact star which gives the radial pressure is purely the function of density i.e. pr=f(ρ).

  20. Optogenetic manipulation of neural circuits in awake marmosets.

    PubMed

    MacDougall, Matthew; Nummela, Samuel U; Coop, Shanna; Disney, Anita; Mitchell, Jude F; Miller, Cory T

    2016-09-01

    Optogenetics has revolutionized the study of functional neuronal circuitry (Boyden ES, Zhang F, Bamberg E, Nagel G, Deisseroth K. Nat Neurosci 8: 1263-1268, 2005; Deisseroth K. Nat Methods 8: 26-29, 2011). Although these techniques have been most successfully implemented in rodent models, they have the potential to be similarly impactful in studies of nonhuman primate brains. Common marmosets (Callithrix jacchus) have recently emerged as a candidate primate model for gene editing, providing a potentially powerful model for studies of neural circuitry and disease in primates. The application of viral transduction methods in marmosets for identifying and manipulating neuronal circuitry is a crucial step in developing this species for neuroscience research. In the present study we developed a novel, chronic method to successfully induce rapid photostimulation in individual cortical neurons transduced by adeno-associated virus to express channelrhodopsin (ChR2) in awake marmosets. We found that large proportions of neurons could be effectively photoactivated following viral transduction and that this procedure could be repeated for several months. These data suggest that techniques for viral transduction and optical manipulation of neuronal populations are suitable for marmosets and can be combined with existing behavioral preparations in the species to elucidate the functional neural circuitry underlying perceptual and cognitive processes. PMID:27334951

  1. Brainstem areas activated by intermittent apnea in awake unrestrained rats.

    PubMed

    Ferreira, C B; Schoorlemmer, G H; Rossi, M V; Takakura, A C; Barna, B F; Moreira, T S; Cravo, S L

    2015-06-25

    We investigated the role of the autonomic nervous system to cardiovascular responses to obstructive apnea in awake, unrestrained rats, and measured expression of Fos induced by apnea in the brainstem. We implanted a tracheal balloon contained in a rigid tube to allow the induction of apnea without inducing pain in the trachea. During bouts of 15s of apnea, heart rate fell from 371±8 to 161±11bpm (mean±SEM, n=15, p<0.01) and arterial pressure increased from 115±2 to 131±4mmHg (p<0.01). Bradycardia was due to parasympathetic activity because it was blocked by the muscarinic antagonist, methylatropine. The pressor response was due to vasoconstriction caused by sympathetic activation because it was blocked by the α1 antagonist, prazosin. Apnea induced Fos expression in several brainstem areas involved in cardiorespiratory control such as the nucleus of the solitary tract (NTS), ventrolateral medulla (VLM), and pons. Ligation of the carotid body artery reduced apnea-induced bradycardia, blocked heart rate responses to i.v. injection of cyanide, reduced Fos expression in the caudal NTS, and increased Fos expression in the rostral VLM. In conclusion, apnea activates neurons in regions that process signals from baroreceptors, chemoreceptors, pulmonary receptors, and regions responsible for autonomic and respiratory activity both in the presence and absence of carotid chemoreceptors.

  2. Functional Connectivity Hubs and Networks in the Awake Marmoset Brain

    PubMed Central

    Belcher, Annabelle M.; Yen, Cecil Chern-Chyi; Notardonato, Lucia; Ross, Thomas J.; Volkow, Nora D.; Yang, Yihong; Stein, Elliot A.; Silva, Afonso C.; Tomasi, Dardo

    2016-01-01

    In combination with advances in analytical methods, resting-state fMRI is allowing unprecedented access to a better understanding of the network organization of the brain. Increasing evidence suggests that this architecture may incorporate highly functionally connected nodes, or “hubs”, and we have recently proposed local functional connectivity density (lFCD) mapping to identify highly-connected nodes in the human brain. Here, we imaged awake nonhuman primates to test whether, like the human brain, the marmoset brain contains FC hubs. Ten adult common marmosets (Callithrix jacchus) were acclimated to mild, comfortable restraint using individualized helmets. Following restraint training, resting BOLD data were acquired during eight consecutive 10 min scans for each subject. lFCD revealed prominent cortical and subcortical hubs of connectivity across the marmoset brain; specifically, in primary and secondary visual cortices (V1/V2), higher-order visual association areas (A19M/V6[DM]), posterior parietal and posterior cingulate areas (PGM and A23b/A31), thalamus, dorsal and ventral striatal areas (caudate, putamen, lateral septal nucleus, and anterior cingulate cortex (A24a). lFCD hubs were highly connected to widespread areas of the brain, and further revealed significant network-network interactions. These data provide a baseline platform for future investigations in a nonhuman primate model of the brain’s network topology. PMID:26973476

  3. Spontaneous cortical activity in awake monkeys composed of neuronal avalanches.

    PubMed

    Petermann, Thomas; Thiagarajan, Tara C; Lebedev, Mikhail A; Nicolelis, Miguel A L; Chialvo, Dante R; Plenz, Dietmar

    2009-09-15

    Spontaneous neuronal activity is an important property of the cerebral cortex but its spatiotemporal organization and dynamical framework remain poorly understood. Studies in reduced systems--tissue cultures, acute slices, and anesthetized rats--show that spontaneous activity forms characteristic clusters in space and time, called neuronal avalanches. Modeling studies suggest that networks with this property are poised at a critical state that optimizes input processing, information storage, and transfer, but the relevance of avalanches for fully functional cerebral systems has been controversial. Here we show that ongoing cortical synchronization in awake rhesus monkeys carries the signature of neuronal avalanches. Negative LFP deflections (nLFPs) correlate with neuronal spiking and increase in amplitude with increases in local population spike rate and synchrony. These nLFPs form neuronal avalanches that are scale-invariant in space and time and with respect to the threshold of nLFP detection. This dimension, threshold invariance, describes a fractal organization: smaller nLFPs are embedded in clusters of larger ones without destroying the spatial and temporal scale-invariance of the dynamics. These findings suggest an organization of ongoing cortical synchronization that is scale-invariant in its three fundamental dimensions--time, space, and local neuronal group size. Such scale-invariance has ontogenetic and phylogenetic implications because it allows large increases in network capacity without a fundamental reorganization of the system.

  4. Fiber optic based multisensor to brain neurons in awake animals

    NASA Astrophysics Data System (ADS)

    Shen, Zheng; Lin, Shuzhi

    1995-02-01

    The fibeated broptic-based multisensor was made of quartz optic fiber capillary with an outer diameter of 250 micrometers and an inner diameter of 10 micrometers through two methods: a capillary and the parallel capillary with another piece of optic fiber. There was a thin layer of tungsten membrane (thickness 1 micrometers ) around the outer surface of the optic fiber or capillary. The metal membrane worked as a micro electrode or an electro-osmosis electrode. Nitrogen laser beam and laser-fluorescent pulses were guided in two ways through optic fiber or the wall of the capillary. The advantage of one capillary was its small tip and measurement of different physiological indices in the same site, but the intensity of laser-fluorescent pulses was diminished by electro-osmosis flow; the parallel optic fiber and capillary avoided the shortage, but the device tip was bigger than a capillary. The multisensor was used to inquire into cognitive brain mechanism in awake animals by simultaneous recording of neuron activities (neuron firing), neuron metabolism rate (laser-fluorescent pulses), and biochemical events through microelectrophore in vivo and field effect electro-osmosis analysis at situ. The effects of nitric oxide biosynthesis-related compounds on neuron efficiency of the cortex were investigated by the multisensor.

  5. Cognitive outcome after awake surgery for tumors in language areas.

    PubMed

    Santini, B; Talacchi, A; Squintani, G; Casagrande, F; Capasso, R; Miceli, G

    2012-06-01

    In surgery for tumors of the dominant hemisphere, the attention devoted to quality of resection and preservation of language function has not been accompanied by comparable interest in preservation of cognitive abilities which may affect quality of life. We studied 22 patients undergoing awake surgery for glioma removal in the language areas of the brain. Besides monitoring tumor variables (size, location, histology, edema), we used a multifaceted battery of tests to investigate mood, cognition, and language in an attempt to assess the burden of disease and treatment, and the relationships between these three dimensions. Baseline assessment showed that 45% of the patients were depressed and 23% anxious; some cognitive and language impairment was noted for 59 and 50%, respectively. A general decline in postoperative cognitive performance (significant for memory and attention only) and language function (significant for picture naming) was observed, whereas depression was unchanged and anxiety decreased. Tumor histology, but not demographic variables or extent of resection, correlated with postoperative cognitive changes: patients undergoing surgery for high-grade tumors were more likely to improve. No correlation was observed between scores for mood, cognition, and language function. A subset of patients with low-grade glioma was followed up for 3-6 months; although some improvement was observed they did not always regain their preoperative performance. In conclusion, we believe that cognitive assessment performed in conjunction with language testing is a necessary step in the global evaluation of brain tumor patients both before and after surgery.

  6. Perfusion Imaging with a Freely Diffusible Hyperpolarized Contrast Agent

    PubMed Central

    Grant, Aaron K.; Vinogradov, Elena; Wang, Xiaoen; Lenkinski, Robert E.; Alsop, David C.

    2011-01-01

    Contrast agents that can diffuse freely into or within tissue have numerous attractive features for perfusion imaging. Here we present preliminary data illustrating the suitability of hyperpolarized 13C labeled 2-methylpropan-2-ol (also known as dimethylethanol, tertiary butyl alcohol and tert-butanol) as a freely diffusible contrast agent for magnetic resonance perfusion imaging. Dynamic 13C images acquired in rat brain with a balanced steady-state free precession (bSSFP) sequence following administration of hyperpolarized 2-methylpropan-2-ol show that this agent can be imaged with 2–4s temporal resolution, 2mm slice thickness, and 700 micron in-plane resolution while retaining adequate signal-to-noise ratio. 13C relaxation measurements on 2-methylpropan-2-ol in blood at 9.4T yield T1=46±4s and T2=0.55±0.03s. In the rat brain at 4.7T, analysis of the temporal dynamics of the bSSFP image intensity in tissue and venous blood indicate that 2-methylpropan-2-ol has a T2 of roughly 2–4s and a T1 of 43±24s. In addition, the images indicate that 2-methylpropan-2-ol is freely diffusible in brain and hence has a long residence time in tissue; this in turn makes it possible to image the agent continuously for tens of seconds. These characteristics show that 2-methylpropan-2-ol is a promising agent for robust and quantitative perfusion imaging in the brain and body. PMID:21432901

  7. Flagellar waveform dynamics of freely swimming algal cells

    NASA Astrophysics Data System (ADS)

    Kurtuldu, H.; Tam, D.; Hosoi, A. E.; Johnson, K. A.; Gollub, J. P.

    2013-07-01

    We present quantitative measurements of time-dependent flagellar waveforms for freely swimming biflagellated algal cells, for both synchronous and asynchronous beating. We use the waveforms in conjunction with resistive force theory as well as a singularity method to predict a cell's time-dependent velocity for comparison with experiments. While net propulsion is thought to arise from asymmetry between the power and recovery strokes, we show that hydrodynamic interactions between the flagella and cell body on the return stroke make an important contribution to enhance net forward motion.

  8. Velocity measurements around a freely swimming fish using PIV

    NASA Astrophysics Data System (ADS)

    Kamran Siddiqui, M. H.

    2007-01-01

    Two-dimensional velocity fields around a freely swimming goldfish in a vertical plane have been measured using the particle image velocimetry (PIV) technique. A novel scheme has been developed to detect the fish body in each PIV image. The scheme is capable of detecting the bodies of fish and other aquatic animals with multicolour skin and different patterns. In this scheme, the body portions brighter and darker than the background are extracted separately and then combined together to construct the entire body. The velocity fields show that the fins and tail produce jets. Vortices are also observed in the wake region.

  9. Local domains of motor cortical activity revealed by fiber-optic calcium recordings in behaving nonhuman primates.

    PubMed

    Adelsberger, Helmuth; Zainos, Antonio; Alvarez, Manuel; Romo, Ranulfo; Konnerth, Arthur

    2014-01-01

    Brain mapping experiments involving electrical microstimulation indicate that the primary motor cortex (M1) directly regulates muscle contraction and thereby controls specific movements. Possibly, M1 contains a small circuit "map" of the body that is formed by discrete local networks that code for specific movements. Alternatively, movements may be controlled by distributed, larger-scale overlapping circuits. Because of technical limitations, it remained unclear how movement-determining circuits are organized in M1. Here we introduce a method that allows the functional mapping of small local neuronal circuits in awake behaving nonhuman primates. For this purpose, we combined optic-fiber-based calcium recordings of neuronal activity and cortical microstimulation. The method requires targeted bulk loading of synthetic calcium indicators (e.g., OGB-1 AM) for the staining of neuronal microdomains. The tip of a thin (200 µm) optical fiber can detect the coherent activity of a small cluster of neurons, but is insensitive to the asynchronous activity of individual cells. By combining such optical recordings with microstimulation at two well-separated sites of M1, we demonstrate that local cortical activity was tightly associated with distinct and stereotypical simple movements. Increasing stimulation intensity increased both the amplitude of the movements and the level of neuronal activity. Importantly, the activity remained local, without invading the recording domain of the second optical fiber. Furthermore, there was clear response specificity at the two recording sites in a trained behavioral task. Thus, the results provide support for movement control in M1 by local neuronal clusters that are organized in discrete cortical domains. PMID:24344287

  10. Nonlinear fluctuation effects in dynamics of freely suspended films

    NASA Astrophysics Data System (ADS)

    Kats, E. I.; Lebedev, V. V.

    2015-03-01

    Long-scale dynamic fluctuation phenomena in freely suspended films is analyzed. We consider isotropic films that, say, can be pulled from bulk smectic-A liquid crystals. The key feature of such objects is possibility of bending deformations of the film. The bending (also known as flexular) mode turns out to be anomalously weakly attenuated. In the harmonic approximation there is no viscous-like damping of the bending mode, proportional to q2 (q is the wave vector of the mode), since it is forbidden by the rotational symmetry. Therefore, the bending mode is strongly affected by nonlinear dynamic fluctuation effects. We calculate the dominant fluctuation contributions to the damping of the bending mode due to its coupling to the inplane viscous mode, which restores the viscous-like q2 damping of the bending mode. Our calculations are performed in the framework of the perturbation theory where the coupling of the modes is assumed to be small, then the bending mode damping is relatively weak. We discuss our results in the context of existing experiments and numeric simulations of the freely suspended films and propose possible experimental observations of our predictions.

  11. A freely falling magneto-optical trap drop tower experiment

    NASA Astrophysics Data System (ADS)

    Könemann, T.; Brinkmann, W.; Göklü, E.; Lämmerzahl, C.; Dittus, H.; van Zoest, T.; Rasel, E. M.; Ertmer, W.; Lewoczko-Adamczyk, W.; Schiemangk, M.; Peters, A.; Vogel, A.; Johannsen, G.; Wildfang, S.; Bongs, K.; Sengstock, K.; Kajari, E.; Nandi, G.; Walser, R.; Schleich, W. P.

    2007-12-01

    We experimentally demonstrate the possibility of preparing ultracold atoms in the environment of weightlessness at the earth-bound short-term microgravity laboratory Drop Tower Bremen, a facility of ZARM - University of Bremen. Our approach is based on a freely falling magneto-optical trap (MOT) drop tower experiment performed within the ATKAT collaboration (“Atom-Catapult”) as a preliminary part of the QUANTUS pilot project (“Quantum Systems in Weightlessness”) pursuing a Bose-Einstein condensate (BEC) in microgravity at the drop tower [1, 2]. Furthermore we give a complete account of the specific drop tower requirements to realize a compact and robust setup for trapping and cooling neutral rubidium 87Rb atoms in microgravity conditions. We also present the results of the first realized freely falling MOT and further accomplished experiments during several drops. The goal of the preliminary ATKAT pilot project is to initiate a basis for extended atom-optical experiments which aim at realizing, observing and investigating ultracold quantum matter in microgravity.

  12. Freely-tunable broadband polarization rotator for terahertz waves

    NASA Astrophysics Data System (ADS)

    Peng, Ru-Wen; Fan, Ren-Hao; Zhou, Yu; Jiang, Shang-Chi; Xiong, Xiang; Huang, Xian-Rong; Wang, Mu

    It is known that commercially-available terahertz (THz) emitters usually generate linearly polarized waves only along certain directions, but in practice, a polarization rotator that is capable of rotating the polarization of THz waves to any direction is particularly desirable and it will have various important applications. In this work, we demonstrate a freely tunable polarization rotator for broadband THz waves using a three-rotating-layer metallic grating structure, which can conveniently rotate the polarization of a linearly polarized THz wave to any desired direction with nearly perfect conversion efficiency. The device performance has been experimentally demonstrated by both THz transmission spectra and direct imaging. The polarization rotation originates from multi wave interference in the three-layer grating structure based on the scattering-matrix analysis. We can expect that this active broadband polarization rotator has wide applications in analytical chemistry, biology, communication technology, imaging, etc.. Reference: R. H. Fan, Y. Zhou, X. P. Ren, R. W. Peng, S. C. Jiang, D. H. Xu, X. Xiong, X. R. Huang, and Mu Wang, Advanced Materials 27,1201(2015). Freely-tunable broadband polarization rotator for terahertz waves.

  13. Structure and Dynamics of Freely Suspended Liquid Crystals

    NASA Technical Reports Server (NTRS)

    Clark, Noel A.

    2004-01-01

    Smectic liquid crystals are phases of rod shaped molecules organized into one dimensionally (1 D) periodic arrays of layers, each layer being between one and two molecular lengths thick. In the least ordered smectic phases, the smectics A and C, each layer is a two dimensional (2D) liquid. Additionally there are a variety of more ordered smectic phases having hexatic short range translational order or 2D crystalline or quasi long range translational order within the layers. The inherent fluid-layer structure and low vapor pressure of smectic liquid crystals enables the long term stabilization of freely suspended, single component, layered fluid films as thin as 30A, a single molecular layer. The layering forces the films to be an integral number of smectic layers thick, quantizing their thickness in layer units and forcing a film of a particular number of layers to be physically homogeneous with respect to its layer structure over its entire area. Optical reflectivity enables the precise determination of the number of layers. These ultrathin freely suspended liquid crystal films are structures of fundamental interest in condensed matter and fluid physics. They are the thinnest known stable fluid structures and have the largest surface-to-volume ratio of any stable fluid preparation, making them ideal for the study of the effects of reduced dimensionality on phase behavior and on fluctuation and interface phenomena. Their low vapor pressure and quantized thickness enable the effective use of microgravity to extend the study of basic capillary phenomena to ultrathin fluid films. Freely suspended films have been a wellspring of new LC physics. They have been used to provide unique experimental conditions for the study of condensed phase transitions in two dimensions. They are the only system in which the hexatic has been unambiguously identified as a phase of matter, and the only physical system in which fluctuations of a 2D XY system and Kosterlitz Thouless phase

  14. Spectral analysis of ventilation in elderly subjects awake and asleep.

    PubMed

    Pack, A I; Silage, D A; Millman, R P; Knight, H; Shore, E T; Chung, D C

    1988-03-01

    We studied the periodicities of ventilation in elderly subjects using digital comb filtering. Two groups of subjects were studied, those with and without sleep apnea. Measurements were made in wakefulness, stage 1-2 sleep, and where possible in stage 3-4 sleep. For each of the digital filters we calculated the average power of the oscillatory output. To compare subject groups we first specifically determined the average power in the filter with the maximum output. The mean of this measurement was greater in elderly subjects with apnea compared with those without apnea, both during wakefulness and stage 1-2 sleep. In both groups of subjects the cycle time of the major ventilatory oscillations was on the order of 40-60 s. There was no difference in this cycle time between the two groups of subjects in wakefulness or stage 1-2 sleep. Thus, whereas similar oscillatory processes occur in subjects with and without apnea, it is the magnitude of the oscillation that differs between the two groups. These conclusions are supported by analysis of the output of individual filters of the digital comb filter. In both groups, stage 1-2 sleep produced significantly increased oscillations in ventilation. Both in wakefulness and stage 1-2 sleep, significantly greater periodicities occurred in the apneic compared with the nonapneic group. In the few subjects who had sufficient data in stage 3-4 sleep for spectral analysis, ventilatory oscillations were virtually absent in this state. Our data suggest that subjects who develop apnea during sleep have an increased propensity for periodic breathing even while awake.

  15. Stability of thalamocortical synaptic transmission across awake brain states.

    PubMed

    Stoelzel, Carl R; Bereshpolova, Yulia; Swadlow, Harvey A

    2009-05-27

    Sensory cortical neurons are highly sensitive to brain state, with many neurons showing changes in spatial and/or temporal response properties and some neurons becoming virtually unresponsive when subjects are not alert. Although some of these changes are undoubtedly attributable to state-related filtering at the thalamic level, another likely source of such effects is the thalamocortical (TC) synapse, where activation of nicotinic receptors on TC terminals have been shown to enhance synaptic transmission in vitro. However, monosynaptic TC synaptic transmission has not been directly examined during different states of alertness. Here, in awake rabbits that shifted between alert and non-alert EEG states, we examined the monosynaptic TC responses and short-term synaptic dynamics generated by spontaneous impulses of single visual and somatosensory TC neurons. We did this using spike-triggered current source-density analysis, an approach that enables assessment of monosynaptic extracellular currents generated in different cortical layers by impulses of single TC afferents. Spontaneous firing rates of TC neurons were higher, and burst rates were much lower in the alert state. However, we found no state-related changes in the amplitude of monosynaptic TC responses when TC spikes with similar preceding interspike interval were compared. Moreover, the relationship between the preceding interspike interval of the TC spike and postsynaptic response amplitude was not influenced by state. These data indicate that TC synaptic transmission and dynamics are highly conserved across different states of alertness and that observed state-related changes in receptive field properties that occur at the cortical level result from other mechanisms.

  16. Psychophysical measurement of contrast sensitivity in the behaving mouse

    PubMed Central

    Carvalho, Lauren A.; Maunsell, John H. R.

    2012-01-01

    To understand how activity in mammalian neural circuits controls behavior, the mouse is a promising model system due to the convergence of genetic, optical, and physiological methods. The ability to control and quantify behavior precisely is also essential for these studies. We developed an operant visual detection paradigm to make visual psychophysical measurements: head-fixed mice make responses by pressing a lever. We designed this task to permit neurophysiological studies of behavior in cerebral cortex, where activity is variable from trial to trial and neurons encode many types of information simultaneously. To study neural responses in the face of this complexity, we trained mice to do a task where they perform hundreds of trials daily and perceptual thresholds can be measured. We used this task to measure both visual acuity and the minimum detectable contrast in behaving mice. We found that the mouse contrast response function is similar in shape to other species. They can detect low-contrast stimuli, with a peak contrast threshold of 2%, equivalent to ∼15° eccentric in human vision. Mouse acuity is modest, with an upper limit near 0.5 cycles/°, consistent with prior data. PMID:22049334

  17. Awake Measures of Nasal Resistance and Upper Airway Resistance on CPAP during Sleep

    PubMed Central

    Masdeu, Maria J.; Seelall, Vijay; Patel, Amit V.; Ayappa, Indu; Rapoport, David M.

    2011-01-01

    Study Objectives: Since on CPAP, the nose is the primary determinant of upper airway resistance, we assess utility of noninvasive measures of nasal resistance during wakefulness as a predictor of directly assessed upper airway resistance on CPAP during sleep in patients with obstructive sleep apnea/hypopnea syndrome. Methods: Patients with complaints of snoring and excessive daytime sleepiness were recruited. 14 subjects underwent daytime evaluations including clinical assessment, subjective questionnaires to assess nasal symptoms and evaluation of nasal resistance with acoustic rhinometry (AR) and active anterior rhinomanometry (RM) in the sitting and supine positions. Patients underwent nocturnal polysomnography on optimal CPAP with measurements of supraglottic pressure to evaluate upper airway resistance. Comparisons were made between nasal resistance using AR and RM during wakefulness, and between AR and RM awake and upper airway resistance during sleep. Results: Our study shows that measures of awake nasal resistance using AR and RM had little or no correlation to each other in the sitting position, whereas there was significant but weak correlation in the supine position. Upper airway resistance measured while on CPAP during sleep did not show significant relationships to any of the awake measures of nasal resistance (AR or RM). Conclusion: Awake measurements of nasal resistance do not seem to be predictive of upper airway resistance during sleep on CPAP. Citation: Masdeu MJ; Seelall V; Patel AV; Ayappa I; Rapoport DM. Awake Measures of Nasal Resistance and Upper Airway Resistance on CPAP during Sleep. J Clin Sleep Med 2011;7(1):31-40. PMID:21344056

  18. Awake brain tumor resection during pregnancy: Decision making and technical nuances.

    PubMed

    Meng, Lingzhong; Han, Seunggu J; Rollins, Mark D; Gelb, Adrian W; Chang, Edward F

    2016-02-01

    The co-occurrence of primary brain tumor and pregnancy poses unique challenges to the treating physician. If a rapidly growing lesion causes life-threatening mass effect, craniotomy for tumor debulking becomes urgent. The choice between awake craniotomy versus general anesthesia becomes complicated if the tumor is encroaching on eloquent brain because considerations pertinent to both patient safety and oncological outcome, in addition to fetal wellbeing, are involved. A 31-year-old female at 30 weeks gestation with twins presented to our hospital seeking awake craniotomy to resect a 7 × 6 × 5 cm left frontoparietal brain tumor with 7 mm left-to-right subfalcine herniation on imaging that led to word finding difficulty, dysfluency, right upper extremity paralysis, and right lower extremity weakness. She had twice undergone tumor debulking under general anesthesia during the same pregnancy at an outside hospital at 16 weeks and 28 weeks gestation. There were considerations both for and against awake brain tumor resection over surgery under general anesthesia. The decision-making process and the technical nuances related to awake brain tumor resection in this neurologically impaired patient are discussed. Awake craniotomy benefits the patient who harbors a tumor that encroaches on the eloquent brain by allowing a greater extent of resection while preserving the language and sensorimotor function. It can be successfully done in pregnant patients who are neurologically impaired. The patient should be motivated and well informed of the details of the process. A multidisciplinary and collaborative effort is also crucial.

  19. Awake brain tumor resection during pregnancy: Decision making and technical nuances.

    PubMed

    Meng, Lingzhong; Han, Seunggu J; Rollins, Mark D; Gelb, Adrian W; Chang, Edward F

    2016-02-01

    The co-occurrence of primary brain tumor and pregnancy poses unique challenges to the treating physician. If a rapidly growing lesion causes life-threatening mass effect, craniotomy for tumor debulking becomes urgent. The choice between awake craniotomy versus general anesthesia becomes complicated if the tumor is encroaching on eloquent brain because considerations pertinent to both patient safety and oncological outcome, in addition to fetal wellbeing, are involved. A 31-year-old female at 30 weeks gestation with twins presented to our hospital seeking awake craniotomy to resect a 7 × 6 × 5 cm left frontoparietal brain tumor with 7 mm left-to-right subfalcine herniation on imaging that led to word finding difficulty, dysfluency, right upper extremity paralysis, and right lower extremity weakness. She had twice undergone tumor debulking under general anesthesia during the same pregnancy at an outside hospital at 16 weeks and 28 weeks gestation. There were considerations both for and against awake brain tumor resection over surgery under general anesthesia. The decision-making process and the technical nuances related to awake brain tumor resection in this neurologically impaired patient are discussed. Awake craniotomy benefits the patient who harbors a tumor that encroaches on the eloquent brain by allowing a greater extent of resection while preserving the language and sensorimotor function. It can be successfully done in pregnant patients who are neurologically impaired. The patient should be motivated and well informed of the details of the process. A multidisciplinary and collaborative effort is also crucial. PMID:26498092

  20. Associations of Sleep Quality and Awake Physical Activity with Fluctuations in Nocturnal Blood Pressure in Patients with Cardiovascular Risk Factors

    PubMed Central

    Kadoya, Manabu; Koyama, Hidenori; Kurajoh, Masafumi; Naka, Mariko; Miyoshi, Akio; Kanzaki, Akinori; Kakutani, Miki; Shoji, Takuhito; Moriwaki, Yuji; Yamamoto, Tetsuya; Inaba, Masaaki; Namba, Mitsuyoshi

    2016-01-01

    Background Sleep quality and awake physical activity are important behavioral factors involved in the occurrence of cardiovascular diseases, potentially through nocturnal blood pressure (BP) changes. However, the impacts of quantitatively measured sleep quality and awake physical activity on BP fluctuation, and their relationships with several candidate causal factors for nocturnal hypertension are not well elucidated. Methods This cross-sectional study included 303 patients registered in the HSCAA study. Measurements included quantitatively determined sleep quality parameters and awake physical activity obtained by actigraph, nocturnal systolic BP (SBP) fall [100 × (1- sleep SBP/awake SBP ratio)], apnea hypopnea index, urinary sodium and cortisol secretion, plasma aldosterone concentration and renin activity, insulin resistance index, parameters of heart rate variability (HRV), and plasma brain-derived neurotrophic factor (BDNF). Results Simple regression analysis showed that time awake after sleep onset (r = -0.150), a parameter of sleep quality, and awake physical activity (r = 0.164) were significantly correlated with nocturnal SBP fall. Among those, time awake after sleep onset (β = -0.179) and awake physical activity (β = 0.190) were significantly and independently associated with nocturnal SBP fall in multiple regression analysis. In a subgroup of patients without taking anti-hypertensive medications, both time awake after sleep onset (β = -0.336) and awake physical activity (β = 0.489) were more strongly and independently associated with nocturnal SBP falls. Conclusion Sleep quality and awake physical activity were found to be significantly associated with nocturnal SBP fall, and that relationship was not necessarily confounded by candidate causal factors for nocturnal hypertension. PMID:27166822

  1. From viscous to elastic sheets: Dynamics of smectic freely floating films

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; Harth, Kirsten; May, Kathrin; Trittel, Torsten

    The dynamics of droplets and bubbles, particularly on microscopic scales, are of considerable importance in biological, environmental, and technical contexts. Soap bubbles, vesicles and components of biological cells are well known examples where the dynamic behavior is significantly influenced by the properties of thin membranes enclosed by fluids. Two-dimensional membrane motions couple to 3D shape transformations. Smectic liquid crystal mesogens form phases with internal molecular layer order. Free-standing films are easily prepared from this class of materials. They represent simple model systems for membrane dynamics and pattern formation in a quasi two-dimensional fluid. These films are usually spanned over a frame, and they can be inflated to bubbles on a support. Recently, closed microscopic shells of liquid-crystalline materials suspended in an outer fluid without contact to a solid support have been introduced and studied. With a special technique, we prepare millimetre to centimetre sized smectic bubbles in air (similar to soap bubbles). Their distinct feature is the fact that any change of surface area is coupled to a restructuring of the layers in the membrane. High-speed cameras are used to observe the shape transformations of freely floating bubbles from a distorted initial shape to a sphere. Bursting dynamics are recorded and compared to models. Most strikingly, an unpreceded cross-over from inviscid to viscous and elastic behaviour with increasing thickness of the membrane is found: Whereas thin bubbles behave almost like inviscid fluids, the relaxation dynamics slows down considerably for larger film thicknesses. Surface wrinkling and formation of extrusions are observed. We will present a characterization and an expalantion for the above phenomena.

  2. Intersegmental coupling and recovery from perturbations in freely running cockroaches.

    PubMed

    Couzin-Fuchs, Einat; Kiemel, Tim; Gal, Omer; Ayali, Amir; Holmes, Philip

    2015-01-15

    Cockroaches are remarkably stable runners, exhibiting rapid recovery from external perturbations. To uncover the mechanisms behind this important behavioral trait, we recorded leg kinematics of freely running animals in both undisturbed and perturbed trials. Functional coupling underlying inter-leg coordination was monitored before and during localized perturbations, which were applied to single legs via magnetic impulses. The resulting transient effects on all legs and the recovery times to normal pre-perturbation kinematics were studied. We estimated coupling architecture and strength by fitting experimental data to a six-leg-unit phase oscillator model. Using maximum-likelihood techniques, we found that a network with nearest-neighbor inter-leg coupling best fitted the data and that, although coupling strengths vary among preparations, the overall inputs entering each leg are approximately balanced and consistent. Simulations of models with different coupling strengths encountering perturbations suggest that the coupling schemes estimated from our experiments allow animals relatively fast and uniform recoveries from perturbations.

  3. Optogenetic manipulation of neural activity in freely moving Caenorhabditis elegans

    PubMed Central

    Leifer, Andrew M; Fang-Yen, Christopher; Gershow, Marc; Alkema, Mark J; Samuel, Aravinthan D T

    2011-01-01

    We present an optogenetic illumination system capable of real-time light delivery with high spatial resolution to specified targets in freely moving Caenorhabditis elegans. A tracking microscope records the motion of an unrestrained worm expressing Channelrhodopsin-2 or Halorhodopsin/NpHR in specific cell types. Image processing software analyzes the worm’s position within each video frame, rapidly estimates the locations of targeted cells, and instructs a digital micromirror device to illuminate targeted cells with laser light of the appropriate wavelengths to stimulate or inhibit activity. Since each cell in an unrestrained worm is a rapidly moving target, our system operates at high speed (~50 frames per second) to provide high spatial resolution (~30 µm). To demonstrate the accuracy, flexibility, and utility of our system, we present optogenetic analyses of the worm motor circuit, egg-laying circuit, and mechanosensory circuits that were not possible with previous methods. PMID:21240279

  4. Flagellar Waveform Dynamics of Freely Swimming Algal Cells

    NASA Astrophysics Data System (ADS)

    Gollub, Jerry; Kurtuldu, Huseyin; Johnson, Karl

    2012-02-01

    We study the time-dependent conformation patterns of flagella driving freely swimming algal cells, and use this information to determine the time-dependent forces acting on the cells, the induced cell velocities, and the power injected into the surrounding fluid. Conformational waves are evident along the flagella, as are synchronization transitions. The observed dynamics relate directly to the behavior of the dynein molecular motors ``walking'' along the microtubules of the flagella. We find that the irreversibility giving rise to net propulsion is due to the hydrodynamic interactions between the flagella and cell body. We determine the time-dependent power injected into the fluid by the cell body and flagella, and show that the propulsion efficiency is only about 3%.

  5. Numerical simulation of the dynamics of freely falling discs

    NASA Astrophysics Data System (ADS)

    Chrust, Marcin; Bouchet, Gilles; Dušek, Jan

    2013-04-01

    We present a comprehensive parametric study of the transition scenario of freely falling discs. The motion of the discs is investigated by a direct numerical simulation of the solid-fluid interaction. The discs are assumed to be homogeneous and infinitely thin. The problem is shown to depend on two independent parameters, the Galileo number expressing the ratio between effects of gravity and viscosity and the non-dimensionalized mass characterizing the inertia of the disc. The obtained results are in agreement with known experimental and numerical data and provide both detailed and comprehensive picture of the transition scenario in the two-parameter plane defined by the Galileo number and the non-dimensionalized mass.

  6. Structure, Hydrodynamics, and Phase Transition of Freely Suspended Liquid Crystals

    NASA Technical Reports Server (NTRS)

    Clark, Noel A.

    2000-01-01

    Smectic liquid crystals are phases of rod shaped molecules organized into one dimensionally (1D) periodic arrays of layers, each layer being between one and two molecular lengths thick. In the least ordered smectic phases, the smectics A and C, each layer is a two dimensional (2D) liquid. Additionally there are a variety of more ordered smectic phases having hexatic short range translational order or 2D crystalline quasi long range translational order within the layers. The inherent fluid-layer structure and low vapor pressure of smectic liquid crystals enable the long term stabilization of freely suspended, single component, layered fluid films as thin as 30A, a single molecular layer. The layering forces the films to be an integral number of smectic layers thick, quantizing their thickness in layer units and forcing a film of a particular number of layers to be physically homogeneous with respect to its layer structure over its entire area. Optical reflectivity enables the precise determination of the number of layers. These ultrathin freely suspended liquid crystal films are structures of fundamental interest in condensed matter and fluid physics. They are the thinnest known stable condensed phase fluid structures and have the largest surface-to-volume ratio of any stable fluid preparation, making them ideal for the study of the effects of reduced dimensionality on phase behavior and on fluctuation and interface phenomena. Their low vapor pressure and quantized thickness enable the effective use of microgravity to extend the study of basic capillary phenomena to ultrathin fluid films. Freely suspended films have been a wellspring of new liquid crystal physics. They have been used to provide unique experimental conditions for the study of condensed phase transitions in two dimensions. They are the only system in which the hexatic has been unambiguously identified as a phase of matter, and the only physical system in which fluctuations of a 2D XY system and

  7. [Successful airway management using i-gel in 7 patients undergoing awake craniotomy].

    PubMed

    Matsunami, Katsuaki; Sanuki, Michiyoshi; Yasuuji, Masakazu; Nakanuno, Ryuichi; Kato, Takahiro; Kawamoto, Masashi

    2014-07-01

    In order to secure airway during awake craniotomy, we used i-gel to perform positive-pressure ventilation in 7 patients for their anesthetic management. During removal of a tumor around the motor speech center, anesthetic management including asleep-awake-asleep technique was applied for speech testing. The technique, insertion and re-insertion of i-gel, was needed and it was easy in all the patients. During positive-pressure ventilation, peak pressure, tidal volume both for inspiration and expiration, and endtidal-CO2 were not markedly altered. Leakage around i-gel, and its differences between inspiration and expiration were negligible, while the tidal volume was adequate. We conclude that i-gel is useful for anesthetic management for awake craniotomy procedure for both securing airway and ventilation.

  8. AWAKE, The Advanced Proton Driven Plasma Wakefield Acceleration Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Gschwendtner, E.; Adli, E.; Amorim, L.; Apsimon, R.; Assmann, R.; Bachmann, A.-M.; Batsch, F.; Bauche, J.; Berglyd Olsen, V. K.; Bernardini, M.; Bingham, R.; Biskup, B.; Bohl, T.; Bracco, C.; Burrows, P. N.; Burt, G.; Buttenschön, B.; Butterworth, A.; Caldwell, A.; Cascella, M.; Chevallay, E.; Cipiccia, S.; Damerau, H.; Deacon, L.; Dirksen, P.; Doebert, S.; Dorda, U.; Farmer, J.; Fedosseev, V.; Feldbaumer, E.; Fiorito, R.; Fonseca, R.; Friebel, F.; Gorn, A. A.; Grulke, O.; Hansen, J.; Hessler, C.; Hofle, W.; Holloway, J.; Hüther, M.; Jaroszynski, D.; Jensen, L.; Jolly, S.; Joulaei, A.; Kasim, M.; Keeble, F.; Li, Y.; Liu, S.; Lopes, N.; Lotov, K. V.; Mandry, S.; Martorelli, R.; Martyanov, M.; Mazzoni, S.; Mete, O.; Minakov, V. A.; Mitchell, J.; Moody, J.; Muggli, P.; Najmudin, Z.; Norreys, P.; Öz, E.; Pardons, A.; Pepitone, K.; Petrenko, A.; Plyushchev, G.; Pukhov, A.; Rieger, K.; Ruhl, H.; Salveter, F.; Savard, N.; Schmidt, J.; Seryi, A.; Shaposhnikova, E.; Sheng, Z. M.; Sherwood, P.; Silva, L.; Soby, L.; Sosedkin, A. P.; Spitsyn, R. I.; Trines, R.; Tuev, P. V.; Turner, M.; Verzilov, V.; Vieira, J.; Vincke, H.; Wei, Y.; Welsch, C. P.; Wing, M.; Xia, G.; Zhang, H.

    2016-09-01

    The Advanced Proton Driven Plasma Wakefield Acceleration Experiment (AWAKE) aims at studying plasma wakefield generation and electron acceleration driven by proton bunches. It is a proof-of-principle R&D experiment at CERN and the world's first proton driven plasma wakefield acceleration experiment. The AWAKE experiment will be installed in the former CNGS facility and uses the 400 GeV/c proton beam bunches from the SPS. The first experiments will focus on the self-modulation instability of the long (rms ~12 cm) proton bunch in the plasma. These experiments are planned for the end of 2016. Later, in 2017/2018, low energy (~15 MeV) electrons will be externally injected into the sample wakefields and be accelerated beyond 1 GeV. The main goals of the experiment will be summarized. A summary of the AWAKE design and construction status will be presented.

  9. The development of one-stop wide-awake dupuytren's fasciectomy service: a retrospective review

    PubMed Central

    Bismil, QMK; Bismil, MSK; Bismil, Annamma; Neathey, Julia; Gadd, Judith; Roberts, Sue; Brewster, Jennifer

    2012-01-01

    Objectives To detail the transition to a totally one-stop wide-awake (OSWA) Dupuytren's contracture surgical service. Design Retrospective review of Dupuytren's component of last 1000 OSWA cases. Setting The UK's first totally one-stop wide-awake orthopaedic service. Participants 270 patients with Dupuytren's contracture out of the last 1000 OSWA cases. Main outcome measures Surgical outcomes, patient satisfaction and cost-effectiveness and efficiency. Results The OSWA Dupuytren's model is safe, efficient and effective; with a low complication rate, extremely high patient satisfaction; and cost-savings to the nhs of £2500 per case treated. The service saved the NHS approximately £675,000 for the 270 cases presented. Conclusions A totally one-stop wide-awake Dupuytren's Contracture service is practicable and feasible alternative to the conventional treatment pathway, with benefits in terms of efficiency and cost-effectiveness. PMID:22908029

  10. [Awake Nasotracheal Intubation for a 4-Year-old Boy with an Oral Penetrating Toothbrush Injury].

    PubMed

    Kobayashi, Naoya; Ando, Kokichi; Saito, Kazutomo; Toyama, Hiroaki; Fudeta, Hiroto; Yamauchi, Masanori

    2015-09-01

    We report a case of an oral penetrating injury caused by a toothbrush in a 4-year-old 17-kg boy. The toothbrush was lodged in the right cervical region through the oral cavity, and emergency surgery for removal was planned under general anesthesia. Although mask ventilation was not possible because of the protruding toothbrush handle, awake nasotracheal intubation was successfully performed with a fiber-scope and intravenous fentanyl 25 μg. We conclude that appropriate analgesics could facilitate awake intubation in pediatric patients.

  11. The biology of habitat dominance; can microbes behave as weeds?

    PubMed Central

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-01-01

    Summary Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These ‘microbial weeds’ are able to dominate the communities that develop in fertile but uncolonized – or at least partially vacant – habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi

  12. The biology of habitat dominance; can microbes behave as weeds?

    PubMed

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-09-01

    Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These 'microbial weeds' are able to dominate the communities that develop in fertile but uncolonized--or at least partially vacant--habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi. Some microbes

  13. The biology of habitat dominance; can microbes behave as weeds?

    PubMed

    Cray, Jonathan A; Bell, Andrew N W; Bhaganna, Prashanth; Mswaka, Allen Y; Timson, David J; Hallsworth, John E

    2013-09-01

    Competition between microbial species is a product of, yet can lead to a reduction in, the microbial diversity of specific habitats. Microbial habitats can resemble ecological battlefields where microbial cells struggle to dominate and/or annihilate each other and we explore the hypothesis that (like plant weeds) some microbes are genetically hard-wired to behave in a vigorous and ecologically aggressive manner. These 'microbial weeds' are able to dominate the communities that develop in fertile but uncolonized--or at least partially vacant--habitats via traits enabling them to out-grow competitors; robust tolerances to habitat-relevant stress parameters and highly efficient energy-generation systems; avoidance of or resistance to viral infection, predation and grazers; potent antimicrobial systems; and exceptional abilities to sequester and store resources. In addition, those associated with nutritionally complex habitats are extraordinarily versatile in their utilization of diverse substrates. Weed species typically deploy multiple types of antimicrobial including toxins; volatile organic compounds that act as either hydrophobic or highly chaotropic stressors; biosurfactants; organic acids; and moderately chaotropic solutes that are produced in bulk quantities (e.g. acetone, ethanol). Whereas ability to dominate communities is habitat-specific we suggest that some microbial species are archetypal weeds including generalists such as: Pichia anomala, Acinetobacter spp. and Pseudomonas putida; specialists such as Dunaliella salina, Saccharomyces cerevisiae, Lactobacillus spp. and other lactic acid bacteria; freshwater autotrophs Gonyostomum semen and Microcystis aeruginosa; obligate anaerobes such as Clostridium acetobutylicum; facultative pathogens such as Rhodotorula mucilaginosa, Pantoea ananatis and Pseudomonas aeruginosa; and other extremotolerant and extremophilic microbes such as Aspergillus spp., Salinibacter ruber and Haloquadratum walsbyi. Some microbes

  14. The Sleep Elaboration-Awake Pruning (SEAP) theory of memory: long term memories grow in complexity during sleep and undergo selection while awake. Clinical, psychopharmacological and creative implications.

    PubMed

    Charlton, Bruce G; Andras, Peter

    2009-07-01

    Long term memory (LTM) systems need to be adaptive such that they enhance an organism's reproductive fitness and self-reproducing in order to maintain their complexity of communications over time in the face of entropic loss of information. Traditional 'representation-consolidation' accounts conceptualize memory adaptiveness as due to memories being 'representations' of the environment, and the longevity of memories as due to 'consolidation' processes. The assumption is that memory representations are formed while an animal is awake and interacting with the environment, and these memories are consolidated mainly while the animal is asleep. So the traditional view of memory is 'instructionist' and assumes that information is transferred from the environment into the brain. By contrast, we see memories as arising endogenously within the brain's LTM system mainly during sleep, to create complex but probably maladaptive memories which are then simplified ('pruned') and selected during the awake period. When awake the LTM system is brought into a more intense interaction with past and present experience. Ours is therefore a 'selectionist' account of memory, and could be termed the Sleep Elaboration-Awake Pruning (or SEAP) theory. The SEAP theory explains the longevity of memories in the face of entropy by the tendency for memories to grow in complexity during sleep; and explains the adaptiveness of memory by selection for consistency with perceptions and previous memories during the awake state. Sleep is therefore that behavioural state during which most of the internal processing of the system of LTM occurs; and the reason sleep remains poorly understood is that its primary activity is the expansion of long term memories. By re-conceptualizing the relationship between memory, sleep and the environment; SEAP provides a radically new framework for memory research, with implications for the measurement of memory and the design of empirical investigations in clinical

  15. Visualizing Nanoscopic Topography and Patterns in Freely Standing Thin Films

    NASA Astrophysics Data System (ADS)

    Sharma, Vivek; Zhang, Yiran; Yilixiati, Subinuer

    Thin liquid films containing micelles, nanoparticles, polyelectrolyte-surfactant complexes and smectic liquid crystals undergo thinning in a discontinuous, step-wise fashion. The discontinuous jumps in thickness are often characterized by quantifying changes in the intensity of reflected monochromatic light, modulated by thin film interference from a region of interest. Stratifying thin films exhibit a mosaic pattern in reflected white light microscopy, attributed to the coexistence of domains with various thicknesses, separated by steps. Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed in the course of this study, we spatially resolve for the first time, the landscape of stratifying freely standing thin films. We distinguish nanoscopic rims, mesas and craters, and follow their emergence and growth. In particular, for thin films containing micelles of sodium dodecyl sulfate (SDS), these topological features involve discontinuous, thickness transitions with concentration-dependent steps of 5-25 nm. These non-flat features result from oscillatory, periodic, supramolecular structural forces that arise in confined fluids, and arise due to complex coupling of hydrodynamic and thermodynamic effects at the nanoscale.

  16. Hydrodynamics of Inclusions in Freely Suspended Liquid Crystal Films

    NASA Astrophysics Data System (ADS)

    Qi, Zhiyuan

    Hydrodynamic interaction of pairs of circular inclusions in two-dimensional (2D), fluid smectic membranes suspended in air has been studied systematically. By analyzing their Brownian motion, it is found that the radial mutual mobilities of identical inclusions are independent of their size but that the angular coupling becomes strongly size-dependent when their radius exceeds a characteristic hydrodynamic length. These observations are described well for arbitrary inclusion separations by a model that generalizes the Levine/MacKintosh theory of point-force response functions and uses a boundary-element approach to calculate the mobility matrix for inclusions of finite extent. Beyond that, 2D flow fields generated by a rigid, oscillating post inserted in the film have been measured by analyzing the motion of tracer particles and provide a detailed understanding of the hydrodynamic behavior in the film/gas system. The Brownian diffusion of micron-scale inclusions in freely suspended smectic A liquid crystal films a few nanometers thick and several millimeters in diameter depends strongly on the air surrounding the film. Near atmospheric pressure, the three-dimensionally coupled film/gas system is well described by Hughes/Pailthorpe/White hydrodynamic theory but at lower pressure, the diffusion coefficient increases substantially, tending in high vacuum toward the two-dimensional limit where it is determined by film size. In the absence of air, the films are found to be a nearly ideal physical realization of a two-dimensional, incompressible Newtonian fluid.

  17. Freely propagating open premixed turbulent flames stabilized by swirl

    SciTech Connect

    Chan, C.K.; Lau, K.S.; Chin, W.K.; Cheng, R.K.

    1991-12-01

    A novel means has been developed for using weak swirl to stabilize freely propagating open premixed turbulent flames (swirl numbers between 0.05 to 0.3). By injecting a small amount of air tangentially into the co-flow of a concentric burner, stationary flames can be maintained above the burner exit for a large range of mixture, turbulence and flow conditions. The absence of physical surfaces in the vicinity of the flame provides free access to laser diagnostics. Laser Doppler anemometry and laser Mie scattering measurements of four flames with and without incident turbulence show that their features are typical of wrinkled laminar flames. The most distinct characteristics is that flame stabilization does not rely on flow recirculation. Centrifugal force induced by swirl causes flow divergence, and the flame is maintained at where the local mass flux balances the burning rate. The flame speeds can be estimated based on the centerline velocity vector, which is locally normal to the flame brush. This flame geometry is the closest approximation to the 1-D planar flame for determining fundamental properties to advance turbulent combustion theories. 18 refs.

  18. Freely Decaying Turbulence in Force-free Electrodynamics

    NASA Astrophysics Data System (ADS)

    Zrake, Jonathan; East, William E.

    2016-02-01

    Freely decaying, relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two- and three-dimensional periodic domains in both helical and nonhelical settings. Force-free turbulent relaxation is found to exhibit an inverse cascade in all settings and in three dimensions to have a magnetic energy spectrum consistent with the Kolmogorov 5/3 power law. Three-dimensional relaxations also obey the Taylor hypothesis; they settle promptly into the lowest-energy configuration allowed by conservation of the total magnetic helicity. However, in two dimensions, the relaxed state is a force-free equilibrium whose energy greatly exceeds the Taylor minimum and that contains persistent force-free current layers and isolated flux tubes. We explain this behavior in terms of additional topological invariants that exist only in two dimensions, namely the helicity enclosed within each level surface of the magnetic potential function. The speed and completeness of turbulent magnetic free-energy discharge could help account for rapidly variable gamma-ray emission from the Crab Nebula, gamma-ray bursts, blazars, and radio galaxies.

  19. Freely decaying turbulence in two-dimensional electrostatic gyrokinetics

    SciTech Connect

    Tatsuno, T.; Plunk, G. G.; Barnes, M.; Dorland, W.; Howes, G. G.; Numata, R.

    2012-12-15

    In magnetized plasmas, a turbulent cascade occurs in phase space at scales smaller than the thermal Larmor radius ('sub-Larmor scales') [Tatsuno et al., Phys. Rev. Lett. 103, 015003 (2009)]. When the turbulence is restricted to two spatial dimensions perpendicular to the background magnetic field, two independent cascades may take place simultaneously because of the presence of two collisionless invariants. In the present work, freely decaying turbulence of two-dimensional electrostatic gyrokinetics is investigated by means of phenomenological theory and direct numerical simulations. A dual cascade (forward and inverse cascades) is observed in velocity space as well as in position space, which we diagnose by means of nonlinear transfer functions for the collisionless invariants. We find that the turbulence tends to a time-asymptotic state, dominated by a single scale that grows in time. A theory of this asymptotic state is derived in the form of decay laws. Each case that we study falls into one of three regimes (weakly collisional, marginal, and strongly collisional), determined by a dimensionless number D{sub *}, a quantity analogous to the Reynolds number. The marginal state is marked by a critical number D{sub *}=D{sub 0} that is preserved in time. Turbulence initialized above this value become increasingly inertial in time, evolving toward larger and larger D{sub *}; turbulence initialized below D{sub 0} become more and more collisional, decaying to progressively smaller D{sub *}.

  20. Intersegmental coupling and recovery from perturbations in freely running cockroaches

    PubMed Central

    Couzin-Fuchs, Einat; Kiemel, Tim; Gal, Omer; Ayali, Amir; Holmes, Philip

    2015-01-01

    Cockroaches are remarkably stable runners, exhibiting rapid recovery from external perturbations. To uncover the mechanisms behind this important behavioral trait, we recorded leg kinematics of freely running animals in both undisturbed and perturbed trials. Functional coupling underlying inter-leg coordination was monitored before and during localized perturbations, which were applied to single legs via magnetic impulses. The resulting transient effects on all legs and the recovery times to normal pre-perturbation kinematics were studied. We estimated coupling architecture and strength by fitting experimental data to a six-leg-unit phase oscillator model. Using maximum-likelihood techniques, we found that a network with nearest-neighbor inter-leg coupling best fitted the data and that, although coupling strengths vary among preparations, the overall inputs entering each leg are approximately balanced and consistent. Simulations of models with different coupling strengths encountering perturbations suggest that the coupling schemes estimated from our experiments allow animals relatively fast and uniform recoveries from perturbations. PMID:25609786

  1. Near and far wake structures behind freely flying bats

    NASA Astrophysics Data System (ADS)

    Schunk, Cosima; Swartz, Sharon M.; Breuer, Kenneth S.

    2014-11-01

    While pseudo-volumetric reconstructions of the wakes of flying animals, based on transverse (Trefftz) wake measurements, have become a well-established tool in the study of animal aerodynamics in recent years, there are a number of concerns that persist regarding their use in estimating drag and flight efficiency. Here we report on stereo particle image velocimetry (PIV) measurements behind freely flying bats (Eptesicus fuscus) in both the transverse and streamwise planes. The streamwise plane measurements are taken on the wing as well as in the near and far wake region up to eight chord lengths behind the bat. By organizing the data according to the flight speed, wingbeat phase and the spanwise position of the laser sheet on the wing we are able to connect specific features of the wing and body geometry with observed wake structures and thereby construct a detailed time-space map of the wake. Furthermore, we can quantitatively assess wake distortion and assess the validity of lift and drag estimates based on transverse wake measurements. Supported by AFOSR.

  2. Microdroplets Impinging on Freely Suspended Smectic Films: Three Impact Regimes.

    PubMed

    Dölle, Sarah; Stannarius, Ralf

    2015-06-16

    We employ high-speed video imaging to study microdroplets of a few picoliters volume impacting freely suspended smectic liquid-crystal films. Depending on the impact parameters, in particular, droplet velocity and mass, three different regimes are observed such as trapping, rebounding, and tunneling. Fast droplets penetrate the films completely. After they have passed the film, they are coated with a layer of film material while the original smectic film remains intact. Droplets in a certain intermediate velocity range bounce back from the film. After impact, the film deforms and hurls the droplet back, depleting a substantial share of the initial kinetic energy. Slow droplets are caught and embedded in the film. During impact and tunneling, an appreciable amount of kinetic energy is lost. The energy is partially dissipated during droplet impact and during subsequent mechanical vibrations and oscillations of the film and the droplet. The tunneling process of high-speed droplets can be exploited to prepare smectic shells of well-defined sizes that enclose picoliters of an immiscible liquid.

  3. Differential Effects of Cocaine on Dopamine Neuron Firing in Awake and Anesthetized Rats

    PubMed Central

    Koulchitsky, Stanislav; De Backer, Benjamin; Quertemont, Etienne; Charlier, Corinne; Seutin, Vincent

    2012-01-01

    Cocaine (benzoylmethylecgonine), a natural alkaloid, is a powerful psychostimulant and a highly addictive drug. Unfortunately, the relationships between its behavioral and electrophysiological effects are not clear. We investigated the effects of cocaine on the firing of midbrain dopaminergic (DA) neurons, both in anesthetized and awake rats, using pre-implanted multielectrode arrays and a recently developed telemetric recording system. In anesthetized animals, cocaine (10 mg/kg, intraperitoneally) produced a general decrease of the firing rate and bursting of DA neurons, sometimes preceded by a transient increase in both parameters, as previously reported by others. In awake rats, however, injection of cocaine led to a very different pattern of changes in firing. A decrease in firing rate and bursting was observed in only 14% of DA neurons. Most of the other DA neurons underwent increases in firing rate and bursting: these changes were correlated with locomotor activity in 52% of the neurons, but were uncorrelated in 29% of them. Drug concentration measurements indicated that the observed differences between the two conditions did not have a pharmacokinetic origin. Taken together, our results demonstrate that cocaine injection differentially affects the electrical activity of DA neurons in awake and anesthetized states. The observed increases in neuronal activity may in part reflect the cocaine-induced synaptic potentiation found ex vivo in these neurons. Our observations also show that electrophysiological recordings in awake animals can uncover drug effects, which are masked by general anesthesia. PMID:22298123

  4. Awake nasotracheal fiberoptic intubation and self-positioning followed by anesthesia induction in prone patients

    PubMed Central

    Heng, Lei; Wang, Ming-Yu; Sun, Hou-Liang; Zhu, Shan-Shan

    2016-01-01

    Abstract Anesthesia followed by placement in the prone position takes time and may result in complications. This study aimed to evaluate the feasibility of awake nasotracheal fiberoptic intubation and self-positioning followed by anesthesia induction in prone-positioned patients under general anesthesia. Sixty-two patients (ASA physical status I–II) scheduled for awake nasotracheal fiberoptic intubation and prone self-positioning before surgery under general anesthesia were selected. Patient preparation began with detailed preoperative counseling regarding the procedure. Premedication with sedative and antisialagogue was followed by airway anesthesia with topical lidocaine; then, awake nasotracheal fiberoptic intubation was carried out. The patients then positioned themselves comfortably before induction of general anesthesia. The changes in systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), incidence of coughing or gagging, and rate pressure product (RPP) were assessed. Statistical analysis was performed with repeated-measures one-way analysis of variance. Fifty-eight of the 62 patients completed prone self-positioning smoothly. Compared with values before intubation, SBP, DBP, HR, and RPP were slightly increased after intubation, although the difference was not statistically significant (P > 0.05). One patient had moderate coughing and 1 patient had gagging during prone self-positioning, which were tolerable. These findings indicated that awake nasotracheal fiberoptic intubation and self-positioning followed by induction of anesthesia is safe and feasible alternative to routine prone positioning after induction of general anesthesia. PMID:27512858

  5. Evaluation of Gastrointestinal Motility in Awake Rats: A Learning Exercise for Undergraduate Biomedical Students

    ERIC Educational Resources Information Center

    Souza, M. A. N.; Souza, M. H. L. P.; Palheta, R. C., Jr.; Cruz, P. R. M.; Medeiros, B. A.; Rola, F. H.; Magalhaes, P. J. C.; Troncon, L. E. A.; Santos, A. A.

    2009-01-01

    Current medical curricula devote scarce time for practical activities on digestive physiology, despite frequent misconceptions about dyspepsia and dysmotility phenomena. Thus, we designed a hands-on activity followed by a small-group discussion on gut motility. Male awake rats were randomly submitted to insulin, control, or hypertonic protocols.…

  6. a-Band Oscillations in Intracellular Membrane Potentials of Dentate Gyrus Neurons in Awake Rodents

    ERIC Educational Resources Information Center

    Anderson, Ross W.; Strowbridge, Ben W.

    2014-01-01

    The hippocampus and dentate gyrus play critical roles in processing declarative memories and spatial information. Dentate granule cells, the first relay in the trisynaptic circuit through the hippocampus, exhibit low spontaneous firing rates even during locomotion. Using intracellular recordings from dentate neurons in awake mice operating a…

  7. Awake craniotomy in a patient with ejection fraction of 10%: considerations of cerebrovascular and cardiovascular physiology.

    PubMed

    Meng, Lingzhong; Weston, Stephen D; Chang, Edward F; Gelb, Adrian W

    2015-05-01

    A 37-year-old man with nonischemic 4-chamber dilated cardiomyopathy and low-output cardiac failure (estimated ejection fraction of 10%) underwent awake craniotomy for a low-grade oligodendroglioma resection under monitored anesthesia care. The cerebrovascular and cardiovascular physiologic challenges and our management of this patient are discussed.

  8. Characterization of Scale-Free Properties of Human Electrocorticography in Awake and Slow Wave Sleep States

    PubMed Central

    Zempel, John M.; Politte, David G.; Kelsey, Matthew; Verner, Ryan; Nolan, Tracy S.; Babajani-Feremi, Abbas; Prior, Fred; Larson-Prior, Linda J.

    2012-01-01

    Like many complex dynamic systems, the brain exhibits scale-free dynamics that follow power-law scaling. Broadband power spectral density (PSD) of brain electrical activity exhibits state-dependent power-law scaling with a log frequency exponent that varies across frequency ranges. Widely divergent naturally occurring neural states, awake and slow wave sleep (SWS), were used to evaluate the nature of changes in scale-free indices of brain electrical activity. We demonstrate two analytic approaches to characterizing electrocorticographic (ECoG) data obtained during awake and SWS states. A data-driven approach was used, characterizing all available frequency ranges. Using an equal error state discriminator (EESD), a single frequency range did not best characterize state across data from all six subjects, though the ability to distinguish awake and SWS ECoG data in individual subjects was excellent. Multi-segment piecewise linear fits were used to characterize scale-free slopes across the entire frequency range (0.2–200 Hz). These scale-free slopes differed between awake and SWS states across subjects, particularly at frequencies below 10 Hz and showed little difference at frequencies above 70 Hz. A multivariate maximum likelihood analysis (MMLA) method using the multi-segment slope indices successfully categorized ECoG data in most subjects, though individual variation was seen. In exploring the differences between awake and SWS ECoG data, these analytic techniques show that no change in a single frequency range best characterizes differences between these two divergent biological states. With increasing computational tractability, the use of scale-free slope values to characterize ECoG and EEG data will have practical value in clinical and research studies. PMID:22701446

  9. Do Friends and Nonfriends Behave Differently? A Social Relations Analysis of Children's Behavior.

    ERIC Educational Resources Information Center

    Simpkins, Sandra D.; Parke, Ross D.

    2002-01-01

    Examined how children behave differently with friends and non-friends. Engaged 123 triads of target children, friends, and unacquainted peers in free-play and planning tasks. Found that children behaved more positively but also exhibited more negative behavior with friends than with non-friends. (KK)

  10. Satellite Meteorology Education Resources Freely Available from COMET°

    NASA Astrophysics Data System (ADS)

    Abshire, W. E.; Dills, P. N.

    2011-12-01

    The COMET° Program (www.comet.ucar.edu) receives funding from NOAA NESDIS, EUMETSAT, and the Meteorological Service of Canada to support education and training efforts in satellite meteorology. These partnerships enable COMET to create educational materials of global interest on the application of products from geostationary and polar-orbiting remote sensing platforms. Recently, COMET's satellite education programs have focused on both current and next generation satellites and their relevance to operational forecasters and other communities. By partnering with experts from the Naval Research Laboratory, NOAA-NESDIS and its Cooperative Institutes, MSC, and other user communities, COMET stimulates greater utilization of satellite data and products. COMET also continues to broaden the scope of its training to include materials on the EUMETSAT Polar-orbiting System (EPS) and Meteosat geostationary satellites. EPS represents an important contribution to the Initial Joint Polar System between NOAA and EUMETSAT, while Meteosat Second Generation imaging capabilities provide an authentic proving ground for the next-generation GOES-R imager. This presentation provides an overview of COMET's recent satellite education efforts including courses and publications that focus on topics like multispectral RGB products, detecting atmospheric dust, and climate monitoring from satellites. Over 50 satellite-focused self-paced online materials are freely available via the Satellite Topic area of the MetEd Web site (www.meted.ucar.edu/topics/modules/satellite) and COMET's Environmental Satellite Resource Center (ESRC)(www.meted.ucar.edu/esrc). The ESRC, another important resource developed for use by the geosciences and education communities, is a searchable, database driven Web site that provides easy access to a wide range of useful information and training materials on Earth-observing satellites. Simple free online registration is required to access all training materials and the

  11. Three-dimensional spatial representation in freely swimming fish.

    PubMed

    Burt de Perera, Theresa; Holbrook, Robert I

    2012-08-01

    Research on spatial cognition has focused on how animals encode the horizontal component of space. However, most animals travel vertically within their environments, particularly those that fly or swim. Pelagic fish move with six degrees of freedom and must integrate these components to navigate accurately--how do they do this? Using an assay based on associative learning of the vertical and horizontal components of space within a rotating Y-maze, we found that fish (Astyanax fasciatus) learned and remembered information from both horizontal and vertical axes when they were presented either separately or as an integrated three-dimensional unit. When information from the two components conflicted, the fish used the previously learned vertical information in preference to the horizontal. This not only demonstrates that the horizontal and vertical components are stored separately in the fishes' representation of space (simplifying the problem of 3D navigation), but also suggests that the vertical axis contains particularly salient spatial cues--presumably including hydrostatic pressure. To explore this latter possibility, we developed a physical theoretical model that shows how fish could determine their absolute depth using pressure. We next considered full volumetric spatial cognition. Astyanax were trained to swim towards a reward in a Y-maze that could be rotated, before the arms were removed during probe trials. The subjects were tracked in three dimensions as they swam freely through the surrounding cubic tank. The results revealed that fish are able to accurately encode metric information in a volume, and that the error accrued in the horizontal and vertical axes whilst swimming in probe trials was similar. Together, these experiments demonstrate that unlike in surface-bound rats, the vertical component of the representation of space is vitally important to fishes. We hypothesise that the representation of space in the brain of vertebrates could ultimately be

  12. Autonomic control of bronchial circulation in awake sheep during rest and behaviour.

    PubMed

    McIlveen, S; White, S; Parsons, G

    1997-12-01

    1. We tested the hypothesis that the pattern and the intensity of autonomic mechanisms causing vasoconstriction in the resting bronchial circulation of awake dogs also exists in awake sheep. It was also postulated that sighing behaviour and the associated bronchovascular dilatation induced by non-adrenergic, non-cholinergic (NANC) mechanisms observed in the dog exist in sheep. 2. Bronchial arterial blood flow to lower airways of both lungs of awake sheep was measured continuously using pulsed Doppler flow probes mounted on the bronchial artery at prior thoracotomy. 3. Cumulative and factorial analysis of responses to randomized combinations of autonomic alpha 1-, alpha 2-, beta 1- and beta 2-adrenoceptors and cholinoceptor autonomic blockade suggests that resting vasoconstrictor activity is less in sheep than in dogs. At normal aortic pressure, the autonomic activity of these receptor groups in the sheep lowers bronchial blood flow and conductance by 30%, whereas in the awake dog, the corresponding autonomic effect is 50%. 4. Tonic autonomic control of bronchial conductance can be partitioned in sheep to show significant and separate alpha- and beta-adrenoceptor vasoconstrictor activity at a ratio of 1.8:1, an effect normally offset by a weaker vasodilator alpha-/beta-adrenoceptor interaction. In contrast to the situation in awake dogs, cholinoceptors do not play a role in awake sheep. 5. Nitric oxide (NO) synthase inhibition in sheep using NG-nitro-L-arginine following blockade of alpha- and beta-adrenoceptors and cholinoceptors causes hypertension, but minor changes, if any, in pulmonary pressures or heart rate. Bronchial flow and conductance, however, fall from a higher resting conductance by approximately 50%, suggesting that, normally, resting bronchial flow conductance is dominated by strong tonic NO vasodilator effects that interact with weaker tonic autonomic vasoconstrictor effects. 6. Superimposed (respiratory) behaviours of sighing, sneezing and coughing

  13. Combination of Continuous Dexmedetomidine Infusion with Titrated Ultra-Low-Dose Propofol-Fentanyl for an Awake Craniotomy.

    PubMed

    Das, Samaresh; Al-Mashani, Ali; Suri, Neelam; Salhotra, Neeraj; Chatterjee, Nilay

    2016-08-01

    An awake craniotomy is a continuously evolving technique used for the resection of brain tumours from the eloquent cortex. We report a 29-year-old male patient who presented to the Khoula Hospital, Muscat, Oman, in 2016 with a two month history of headaches and convulsions due to a space-occupying brain lesion in close proximity with the left motor cortex. An awake craniotomy was conducted using a scalp block, continuous dexmedetomidine infusion and a titrated ultra-low-dose of propofolfentanyl. The patient remained comfortable throughout the procedure and the intraoperative neuropsychological tests, brain mapping and tumour resection were successful. This case report suggests that dexmedetomidine in combination with titrated ultra-low-dose propofolfentanyl are effective options during an awake craniotomy, ensuring optimum sedation, minimal disinhibition and a rapid recovery. To the best of the authors' knowledge, this is the first awake craniotomy conducted successfully in Oman. PMID:27606116

  14. Combination of Continuous Dexmedetomidine Infusion with Titrated Ultra-Low-Dose Propofol-Fentanyl for an Awake Craniotomy

    PubMed Central

    Das, Samaresh; Al-Mashani, Ali; Suri, Neelam; Salhotra, Neeraj; Chatterjee, Nilay

    2016-01-01

    An awake craniotomy is a continuously evolving technique used for the resection of brain tumours from the eloquent cortex. We report a 29-year-old male patient who presented to the Khoula Hospital, Muscat, Oman, in 2016 with a two month history of headaches and convulsions due to a space-occupying brain lesion in close proximity with the left motor cortex. An awake craniotomy was conducted using a scalp block, continuous dexmedetomidine infusion and a titrated ultra-low-dose of propofolfentanyl. The patient remained comfortable throughout the procedure and the intraoperative neuropsychological tests, brain mapping and tumour resection were successful. This case report suggests that dexmedetomidine in combination with titrated ultra-low-dose propofolfentanyl are effective options during an awake craniotomy, ensuring optimum sedation, minimal disinhibition and a rapid recovery. To the best of the authors’ knowledge, this is the first awake craniotomy conducted successfully in Oman. PMID:27606116

  15. 5-aminolevulinic acid guidance during awake craniotomy to maximise extent of safe resection of glioblastoma multiforme.

    PubMed

    Corns, Robert; Mukherjee, Soumya; Johansen, Anja; Sivakumar, Gnanamurthy

    2015-01-01

    Overall survival for patients with glioblastoma multiforme (GBM) has been consistently shown to improve when the surgeon achieves a gross total resection of the tumour. It has also been demonstrated that surgical adjuncts such as 5-aminolevulinic acid (5-ALA) fluorescence--which delineates malignant tumour tissue--normal brain tissue margin seen using violet-blue excitation under an operating microscope--helps achieve this. We describe the case of a patient with recurrent left frontal GBM encroaching on Broca's area (eloquent brain). Gross total resection of the tumour was achieved by combining two techniques, awake resection to prevent damage to eloquent brain and 5-ALA fluorescence guidance to maximise the extent of tumour resection.This technique led to gross total resection of all T1-enhancing tumour with the avoidance of neurological deficit. The authors recommend this technique in patients when awake surgery can be tolerated and gross total resection is the aim of surgery. PMID:26177997

  16. Behavioral effects of acclimatization to restraint protocol used for awake animal imaging.

    PubMed

    Reed, Michael D; Pira, Ashley S; Febo, Marcelo

    2013-07-15

    Functional MRI in awake rats involves acclimatization to restraint to minimize motion. We designed a study to examine the effects of an acclimatization protocol (5 days of restraint, 60 min per day) on the emission of 22-kHz ultrasonic vocalizations and performance in a forced swim test (FST). Our results showed that USV calls are reduced significantly by days 3, 4 and 5 of acclimatization. Although the rats showed less climbing activity (and more immobility) in FST on day 5 compared to the 1st day of restraint acclimatization, the difference was not detected once the animals were given a 2-week hiatus. Overall, we showed that animals adapt to the restraint over a five-day period; however, restraint may introduce confounding behavioral outcomes that may hinder the interpretation of results derived from awake rat imaging. The present data warrants further testing of the effects of MRI restraint on behavior.

  17. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences.

    PubMed

    Takahashi, Susumu

    2015-01-01

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as 'what' information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only 'where and when' but also 'what' information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process. PMID:26481131

  18. [Single-port video-assisted thoracic surgery in an awake patient].

    PubMed

    Alonso-García, F J; Navarro-Martínez, J; Gálvez, C; Rivera-Cogollos, M J; Sgattoni, C; Tarí-Bas, I M

    2016-03-01

    Video-assisted thoracic surgery is traditionally carried out with general anaesthesia and endotracheal intubation with double lumen tube. However, in the last few years procedures, such as lobectomies, are being performed with loco-regional anaesthesia, with and without sedation, maintaining the patient awake and with spontaneous breathing, in order to avoid the inherent risks of general anaesthesia, double lumen tube intubation and mechanical ventilation. This surgical approach has also shown to be effective in that it allows a good level of analgesia, maintaining a correct oxygenation and providing a better post-operative recovery. Two case reports are presented in which video-assisted thoracic surgery was used, a lung biopsy and a lung resection, both with epidural anaesthesia and maintaining the patient awake and with spontaneous ventilation, as part of a preliminary evaluation of the anaesthetic technique in this type of surgery.

  19. Hemispheric specialization in the primary auditory area of awake and anesthetized starlings (Sturnus vulgaris).

    PubMed

    George, Isabella; Vernier, Baptiste; Richard, Jean-Pierre; Hausberger, Martine; Cousillas, Hugo

    2004-06-01

    Although evidence exists for a lateralization of song production, few studies have focused on the perceptual aspect of lateralization in songbirds. In the present study, the authors recorded neuronal responses to a variety of species-specific and artificial, nonspecific stimuli in both hemispheres of awake and anesthetized male starlings (Sturnus vulgaris). Recordings were made in the primary auditory area of the songbird brain, the Field L complex. The right hemisphere exhibited significantly more responsive units than the left hemisphere in awake birds, and this difference was significantly reduced in anesthetized birds. Furthermore, clear hemispheric specialization toward categories of behaviorally relevant stimuli and precise parameters of these stimuli were found. The main auditory area of the starling's brain thus appears to show some degree of lateralization. PMID:15174938

  20. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences.

    PubMed

    Takahashi, Susumu

    2015-01-01

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as 'what' information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only 'where and when' but also 'what' information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process.

  1. Retrospective evaluation of airway management with blind awake intubation in temporomandibular joint ankylosis patients: A review of 48 cases

    PubMed Central

    Sankar, Duraiswamy; Krishnan, Radhika; Veerabahu, Muthusubramanian; Vikraman, Bhaskara Pandian; Nathan, J. A.

    2016-01-01

    Aim: The aim was to determine the morbidity or mortality associated with the blind awake intubation technique in temporomandibular ankylosis patients. Settings and Design: A total of 48 cases with radiographically and clinically confirmed cases of temporomandibular joint (TMJ) ankylosis were included in the study for evaluation of anesthetic management and its complications. Materials and Methods: Airway assessment was done with standard proforma including Look externally, evaluate 3-3-2 rule, Mallampati classification, Obstruction, Neck mobility (LEMON) score assessment in all TMJ ankylosis patients. The intubation was carried out with the standard departmental anesthetic protocol in all the patients. The preoperative difficulty assessment and postoperative outcome were recorded. Results: Blind awake intubation was done in 92% of cases, 6% of cases were intubated by fiberoptic awake intubation, and 2% patient required surgical airway. Ninety-eight percent of the patients were cooperative during the awake intubation. The frequent complications encountered during the blind awake intubation were epistaxis and sore throat. Conclusion: In an anesthetic setup, where fiberoptic intubation is not available, blind awake intubation could be considered in the anesthetic management algorithm. PMID:27563608

  2. Development of a simultaneous optical/PET imaging system for awake mice.

    PubMed

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [(11)C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [(11)C]raclopride radioactivity concentration simultaneously. Accumulation of [(11)C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models. PMID:27514436

  3. Development of a simultaneous optical/PET imaging system for awake mice

    NASA Astrophysics Data System (ADS)

    Takuwa, Hiroyuki; Ikoma, Yoko; Yoshida, Eiji; Tashima, Hideaki; Wakizaka, Hidekatsu; Shinaji, Tetsuya; Yamaya, Taiga

    2016-09-01

    Simultaneous measurements of multiple physiological parameters are essential for the study of brain disease mechanisms and the development of suitable therapies to treat them. In this study, we developed a measurement system for simultaneous optical imaging and PET for awake mice. The key elements of this system are the OpenPET, optical imaging and fixation apparatus for an awake mouse. The OpenPET is our original open-type PET geometry, which can be used in combination with another device because of the easily accessible open space of the former. A small prototype of the axial shift single-ring OpenPET was used. The objective lens for optical imaging with a mounted charge-coupled device camera was placed inside the open space of the AS-SROP. Our original fixation apparatus to hold an awake mouse was also applied. As a first application of this system, simultaneous measurements of cerebral blood flow (CBF) by laser speckle imaging (LSI) and [11C]raclopride-PET were performed under control and 5% CO2 inhalation (hypercapnia) conditions. Our system successfully obtained the CBF and [11C]raclopride radioactivity concentration simultaneously. Accumulation of [11C]raclopride was observed in the striatum where the density of dopamine D2 receptors is high. LSI measurements could be stably performed for more than 60 minutes. Increased CBF induced by hypercapnia was observed while CBF under the control condition was stable. We concluded that our imaging system should be useful for investigating the mechanisms of brain diseases in awake animal models.

  4. The kinematic architecture of the Active Headframe: A new head support for awake brain surgery.

    PubMed

    Malosio, Matteo; Negri, Simone Pio; Pedrocchi, Nicola; Vicentini, Federico; Cardinale, Francesco; Tosatti, Lorenzo Molinari

    2012-01-01

    This paper presents the novel hybrid kinematic structure of the Active Headframe, a robotic head support to be employed in brain surgery operations for an active and dynamic control of the patient's head position and orientation, particularly addressing awake surgery requirements. The topology has been conceived in order to satisfy all the installation, functional and dynamic requirements. A kinetostatic optimization has been performed to obtain the actual geometric dimensions of the prototype currently being developed. PMID:23366166

  5. "Awake Veno-arterial Extracorporeal Membrane Oxygenation" in Pediatric Cardiogenic Shock: A Single-Center Experience.

    PubMed

    Schmidt, F; Jack, T; Sasse, M; Kaussen, T; Bertram, H; Horke, A; Seidemann, K; Beerbaum, P; Koeditz, H

    2015-12-01

    In pediatric patients with acute refractory cardiogenic shock (CS), extracorporeal membrane oxygenation (ECMO) remains an established procedure to maintain adequate organ perfusion. In this context, ECMO can be used as a bridging procedure to recovery, VAD or transplantation. While being supported by ECMO, most centers tend to keep their patients well sedated and supported by invasive ventilation. This may be associated with an increased risk of therapy-related morbidity and mortality. In order to optimize clinical management in pediatric patients with ECMO therapy, we report our strategy of veno-arterial ECMO (VA-ECMO) in extubated awake and conscious patients. We therefore present data of six of our patients with CS, who were treated by ECMO being awake without continuous analgosedation and invasive ventilation. Of these six patients, four were <1 year and two >14 years of age. Median time on ECMO was 17.4 days (range 6.9-94.2 days). Median time extubated, while receiving ECMO support was 9.5 days. Mean time extubated was 78 % of the total time on ECMO. Three patients reached full recovery of cardiac function on "Awake-VA-ECMO," whereas the other three were successfully bridged to destination therapy (VAD, heart transplantation, withdrawal). Four out of our six patients are still alive. Complications related to ECMO therapy (i.e., severe bleeding, site infection or dislocation of cannulas) were not observed. We conclude that "Awake-VA-ECMO" in extubated, spontaneously breathing conscious pediatric patients is feasible and safe for the treatment of acute CS and can be used as a "bridging therapy" to recovery, VAD implantation or transplantation.

  6. A chronic cannula for obtaining CSF from the cisterna magna of awake dogs.

    PubMed

    Jennings, D B; Tobin, P

    1979-01-01

    We have designed a cannula system that can be chronically implanted to end above the dura of the cisterna magna of the dog. During experiments in the awake dog, a screw cap with stylet is removed from the cannula and a spinal needle inserted for the withdrawal of samples of cisternal cerebrospinal fluid (CSF) or for making continuous measurements of pressure. The system can be used for repeated experiments extending over several weeks.

  7. The kinematic architecture of the Active Headframe: A new head support for awake brain surgery.

    PubMed

    Malosio, Matteo; Negri, Simone Pio; Pedrocchi, Nicola; Vicentini, Federico; Cardinale, Francesco; Tosatti, Lorenzo Molinari

    2012-01-01

    This paper presents the novel hybrid kinematic structure of the Active Headframe, a robotic head support to be employed in brain surgery operations for an active and dynamic control of the patient's head position and orientation, particularly addressing awake surgery requirements. The topology has been conceived in order to satisfy all the installation, functional and dynamic requirements. A kinetostatic optimization has been performed to obtain the actual geometric dimensions of the prototype currently being developed.

  8. Information flow and coherence of EEG during awake, meditation and drowsiness.

    PubMed

    Dissanayaka, Chamila; Ben-Simon, Eti; Gruberger, Michal; Maron-Katz, Adi; Hendler, Talma; Chaparro-Vargas, Ramiro; Cvetkovic, Dean

    2014-01-01

    A comparison of coupling (information flow) and coherence (connectedness) of the brain regions between human awake, meditation and drowsiness states was carried out in this study. The Directed Transfer Function (DTF) method was used to estimate the coupling or brain's flow of information between different regions during each condition. Welch and Minimum Variance Distortionless Response (MVDR) methods were utilised to estimate the coherence between brain areas. Analysis was conducted using the EEG data of 30 subjects (10 awake, 10 drowsiness and 10 meditating) with 6 EEG electrodes. The EEG data was recorded for each subject during 5 minutes baseline and 15 minutes of three specific conditions (awake, meditation or drowsiness). Statistical analysis was carried out which consisted of the Kruskal-Wallis (KW) non-parametric analysis of variance followed by post-hoc tests with Bonferroni alpha-correction. The results of this study revealed that a change in external awareness led to substantial differences in the spectral profile of the brain's information flow as well as it's connectedness.

  9. Some effects of vagal blockade on abdominal muscle activation and shortening in awake dogs.

    PubMed Central

    Leevers, A M; Road, J D

    1995-01-01

    1. The mechanisms of abdominal muscle activation are thought to be different during expiratory threshold loading (ETL) compared with hypercapnia. Our objectives in the present study were to determine the effects of removing excitatory vagal feedback on abdominal muscle activation, shortening and pattern of recruitment during ETL and hypercapnia. Six tracheotomized dogs were chronically implanted with sonomicrometer transducers and fine wire EMG electrodes in each of the four abdominal muscles. Muscle length changes and EMG activity were studied in the awake dog during ETL (6 dogs) and CO2 rebreathing (3 dogs), before and after vagal blockade. 2. Following vagal blockade, the change in volume (increase in functional residual capacity, FRC) during ETL was greater and active phasic shortening of all the abdominal muscles was reduced, when shortening was compared with a similar change in lung volume. Similarly, at comparable minute ventilation, abdominal muscle active shortening was also reduced during hypercapnia. The internal muscle layer was recruited preferentially in both control and vagally blocked dogs during both ETL and hypercapnia. 3. The degree of recruitment of the abdominal muscles during ETL and hypercapnia in awake dogs is influenced by vagal feedback, but less so than in anaesthetized dogs. These results illustrate the importance of the vagi and abdominal muscle activation in load compensation. However, vagal reflexes are apparently not contributing to the preferential recruitment of the internal muscle layer. In awake dogs during vagal blockade abdominal muscle recruitment still occurs by extravagal mechanisms. PMID:8568685

  10. Anaesthesia Management for Awake Craniotomy: Systematic Review and Meta-Analysis

    PubMed Central

    Rossaint, Rolf; Veldeman, Michael

    2016-01-01

    Background Awake craniotomy (AC) renders an expanded role in functional neurosurgery. Yet, evidence for optimal anaesthesia management remains limited. We aimed to summarise the latest clinical evidence of AC anaesthesia management and explore the relationship of AC failures on the used anaesthesia techniques. Methods Two authors performed independently a systematic search of English articles in PubMed and EMBASE database 1/2007-12/2015. Search included randomised controlled trials (RCTs), observational trials, and case reports (n>4 cases), which reported anaesthetic approach for AC and at least one of our pre-specified outcomes: intraoperative seizures, hypoxia, arterial hypertension, nausea and vomiting, neurological dysfunction, conversion into general anaesthesia and failure of AC. Random effects meta-analysis was used to estimate event rates for four outcomes. Relationship with anaesthesia technique was explored using logistic meta-regression, calculating the odds ratios (OR) and 95% confidence intervals [95%CI]. Results We have included forty-seven studies. Eighteen reported asleep-awake-asleep technique (SAS), twenty-seven monitored anaesthesia care (MAC), one reported both and one used the awake-awake-awake technique (AAA). Proportions of AC failures, intraoperative seizures, new neurological dysfunction and conversion into general anaesthesia (GA) were 2% [95%CI:1–3], 8% [95%CI:6–11], 17% [95%CI:12–23] and 2% [95%CI:2–3], respectively. Meta-regression of SAS and MAC technique did not reveal any relevant differences between outcomes explained by the technique, except for conversion into GA. Estimated OR comparing SAS to MAC for AC failures was 0.98 [95%CI:0.36–2.69], 1.01 [95%CI:0.52–1.88] for seizures, 1.66 [95%CI:1.35–3.70] for new neurological dysfunction and 2.17 [95%CI:1.22–3.85] for conversion into GA. The latter result has to be interpreted cautiously. It is based on one retrospective high-risk of bias study and significance was

  11. View of a stone age adze cutting tool floating freely in the flight deck.

    NASA Technical Reports Server (NTRS)

    1992-01-01

    View of a stone age adze cutting tool floating freely in the forward flight deck and framed by the forward and side windows. On the Earth below, the big island of Hawaii can be seen through the window.

  12. Mapping the Functional Network of Medial Prefrontal Cortex by Combining Optogenetics and fMRI in Awake Rats

    PubMed Central

    Liang, Zhifeng; Watson, Glenn D.R.; Alloway, Kevin D.; Lee, Gangchea; Neuberger, Thomas; Zhang, Nanyin

    2015-01-01

    The medial prefrontal cortex (mPFC) plays a critical role in multiple cognitive and limbic functions. Given its vital importance, investigating the function of individual mPFC circuits in animal models has provided critical insight into the neural basis underlying different behaviors and psychiatric conditions. However, our knowledge regarding the mPFC whole-brain network stays largely at the anatomical level, while the functional network of mPFC, which can be dynamic in different conditions or following manipulations, remains elusive especially in awake rodents. Here we combined optogenetic stimulation and functional magnetic resonance imaging (opto-fMRI) to reveal the network of brain regions functionally activated by mPFC outputs in awake rodents. Our data showed significant increases in blood-oxygenation-level dependent (BOLD) signals in prefrontal, striatal and limbic regions when mPFC was optically stimulated. This activation pattern was robust, reproducible, and did not depend on the stimulation period in awake rats. BOLD signals, however, were substantially reduced when animals were anesthetized. In addition, regional brain activation showing increased BOLD signals during mPFC stimulation was corroborated by electrophysiological recordings. These results expand the applicability of the opto-fMRI approach from sensorimotor processing to cognition-related networks in awake rodents. Importantly, it may help elucidate the circuit mechanisms underlying numerous mPFC-related functions and behaviors that need to be assessed in the awake state. PMID:26002727

  13. Mapping the functional network of medial prefrontal cortex by combining optogenetics and fMRI in awake rats.

    PubMed

    Liang, Zhifeng; Watson, Glenn D R; Alloway, Kevin D; Lee, Gangchea; Neuberger, Thomas; Zhang, Nanyin

    2015-08-15

    The medial prefrontal cortex (mPFC) plays a critical role in multiple cognitive and limbic functions. Given its vital importance, investigating the function of individual mPFC circuits in animal models has provided critical insight into the neural basis underlying different behaviors and psychiatric conditions. However, our knowledge regarding the mPFC whole-brain network stays largely at the anatomical level, while the functional network of mPFC, which can be dynamic in different conditions or following manipulations, remains elusive especially in awake rodents. Here we combined optogenetic stimulation and functional magnetic resonance imaging (opto-fMRI) to reveal the network of brain regions functionally activated by mPFC outputs in awake rodents. Our data showed significant increases in blood-oxygenation-level dependent (BOLD) signals in prefrontal, striatal and limbic regions when mPFC was optically stimulated. This activation pattern was robust, reproducible, and did not depend on the stimulation period in awake rats. BOLD signals, however, were substantially reduced when animals were anesthetized. In addition, regional brain activation showing increased BOLD signals during mPFC stimulation was corroborated by electrophysiological recordings. These results expand the applicability of the opto-fMRI approach from sensorimotor processing to cognition-related networks in awake rodents. Importantly, it may help elucidate the circuit mechanisms underlying numerous mPFC-related functions and behaviors that need to be assessed in the awake state.

  14. Age differences in how consumers behave following exposure to DTC advertising.

    PubMed

    DeLorme, Denise E; Huh, Jisu; Reid, Leonard N

    2006-01-01

    This study was conducted to provide additional evidence on how consumers behave following direct-to-consumer (DTC) advertising exposure and to determine if there are differences in ad-prompted acts (drug inquiry and drug requests) between different age groups (i.e., older, mature, and younger adults). The results suggest that younger, mature, and older consumers are all moved to act by DTC drug ads, but that each age group behaves in different ways. Somewhat surprisingly, age was not predictive of ad-prompted behavior. DTC advertising was no more effective at moving older consumers to behave than their younger counterparts. These results suggest that age does not matter that much when it comes to the "moving power" of prescription drug advertising, even though research indicates that older consumers are more vulnerable to the persuasive effects of communication.

  15. Fear of guilt from behaving irresponsibly in obsessive-compulsive disorder.

    PubMed

    Mancini, Francesco; Gangemi, Amelia

    2004-06-01

    Previous cognitive models of obsessive-compulsive disorder (OCD) propose that inflated responsibility plays a key role in the maintenance of symptoms (Behav.Res.Ther. 28 (1985) 571). In this manuscript, we propose that this thesis may be improved by emphasizing that instead, OCD may be characterized by a fear of guilt that would result from behaving irresponsibly and/or from not behaving responsibly. We believe that this concept provides a better explanation for the anxious and fearful nature of OCD than do more traditional conceptualizations of inflated responsibility. We support this idea with empirical evidence and propose that OCD symptoms are consistent with patients acting in a prudential mode because of their fears of guilt. PMID:15210373

  16. In Vivo Tumour Mapping Using Electrocorticography Alterations During Awake Brain Surgery: A Pilot Study.

    PubMed

    Boussen, Salah; Velly, Lionel; Benar, Christian; Metellus, Philippe; Bruder, Nicolas; Trébuchon, Agnès

    2016-09-01

    During awake brain surgery for tumour resection, in situ EEG recording (ECoG) is used to identify eloquent areas surrounding the tumour. We used the ECoG setup to record the electrical activity of cortical and subcortical tumours and then performed frequency and connectivity analyses in order to identify ECoG impairments and map tumours. We selected 16 patients with cortical (8) and subcortical (8) tumours undergoing awake brain surgery. For each patient, we computed the spectral content of tumoural and healthy areas in each frequency band. We computed connectivity of each electrode using connectivity markers (linear and non-linear correlations, phase-locking and coherence). We performed comparisons between healthy and tumour electrodes. The ECoG alterations were used to implement automated classification of the electrodes using clustering or neural network algorithms. ECoG alterations were used to image cortical tumours.Cortical tumours were found to profoundly alter all frequency contents (normalized and absolute power), with an increase in the δ activity and a decreases for the other bands (P < 0.05). Cortical tumour electrodes showed high level of connectivity compared to surrounding electrodes (all markers, P < 0.05). For subcortical tumours, a relative decrease in the γ1 band and in the alpha band in absolute amplitude (P < 0.05) were the only abnormalities. The neural network algorithm classification had a good performance: 93.6 % of the electrodes were classified adequately on a test subject. We found significant spectral and connectivity ECoG changes for cortical tumours, which allowed tumour recognition. Artificial neural algorithm pattern recognition seems promising for electrode classification in awake tumour surgery. PMID:27324381

  17. In Vivo Tumour Mapping Using Electrocorticography Alterations During Awake Brain Surgery: A Pilot Study.

    PubMed

    Boussen, Salah; Velly, Lionel; Benar, Christian; Metellus, Philippe; Bruder, Nicolas; Trébuchon, Agnès

    2016-09-01

    During awake brain surgery for tumour resection, in situ EEG recording (ECoG) is used to identify eloquent areas surrounding the tumour. We used the ECoG setup to record the electrical activity of cortical and subcortical tumours and then performed frequency and connectivity analyses in order to identify ECoG impairments and map tumours. We selected 16 patients with cortical (8) and subcortical (8) tumours undergoing awake brain surgery. For each patient, we computed the spectral content of tumoural and healthy areas in each frequency band. We computed connectivity of each electrode using connectivity markers (linear and non-linear correlations, phase-locking and coherence). We performed comparisons between healthy and tumour electrodes. The ECoG alterations were used to implement automated classification of the electrodes using clustering or neural network algorithms. ECoG alterations were used to image cortical tumours.Cortical tumours were found to profoundly alter all frequency contents (normalized and absolute power), with an increase in the δ activity and a decreases for the other bands (P < 0.05). Cortical tumour electrodes showed high level of connectivity compared to surrounding electrodes (all markers, P < 0.05). For subcortical tumours, a relative decrease in the γ1 band and in the alpha band in absolute amplitude (P < 0.05) were the only abnormalities. The neural network algorithm classification had a good performance: 93.6 % of the electrodes were classified adequately on a test subject. We found significant spectral and connectivity ECoG changes for cortical tumours, which allowed tumour recognition. Artificial neural algorithm pattern recognition seems promising for electrode classification in awake tumour surgery.

  18. BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience.

    PubMed

    Yee, J R; Kenkel, W M; Kulkarni, P; Moore, K; Perkeybile, A M; Toddes, S; Amacker, J A; Carter, C S; Ferris, C F

    2016-09-01

    The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological

  19. Electrical stimulation of the midbrain increases heart rate and arterial blood pressure in awake humans

    PubMed Central

    Thornton, Judith M; Aziz, Tipu; Schlugman, David; Paterson, David J

    2002-01-01

    Electrical stimulation of the hypothalamus, basal ganglia or pedunculopontine nucleus in decorticate animals results in locomotion and a cardiorespiratory response resembling that seen during exercise. This has led to the hypothesis that parallel activation of cardiorespiratory and locomotor systems from the midbrain could form part of the ‘central command’ mechanism of exercise. However, the degree to which subcortical structures play a role in cardiovascular activation in awake humans has not been established. We studied the effects on heart rate (HR) and mean arterial blood pressure (MAP) of electrically stimulating the thalamus and basal ganglia in awake humans undergoing neurosurgery for movement disorders (n = 13 Parkinson's disease, n = 1 myoclonic dystonia, n = 1 spasmodic torticollis). HR and MAP increased during high frequency (> 90 Hz) electrical stimulation of the thalamus (HR 5 ± 3 beats min−1, P = 0.002, MAP 4 ± 3 mmHg, P = 0.05, n = 9), subthalamic nucleus (HR 5 ± 3 beats min−1, P = 0.002, MAP 5 ± 3 mmHg, P = 0.006, n = 8) or substantia nigra (HR 6 ± 3 beats min−1, P = 0.001, MAP 5 ± 2 mmHg, P = 0.005, n = 8). This was accompanied by the facilitation of movement, but without the movement itself. Stimulation of the internal globus pallidus did not increase cardiovascular variables but did facilitate movement. Low frequency (< 20 Hz) stimulation of any site did not affect cardiovascular variables or movement. Electrical stimulation of the midbrain in awake humans can cause a modest increase in cardiovascular variables that is not dependent on movement feedback from exercising muscles. The relationship between this type of response and that occurring during actual exercise is unclear, but it indicates that subcortical command could be involved in ‘parallel activation’ of the locomotor and cardiovascular systems and thus contribute to the neurocircuitry of ‘central command’. PMID:11882692

  20. Algorithmic complexity as an index of cortical function in awake and pentobarbital-anesthetized rats.

    PubMed

    Shaw, F Z; Chen, R F; Tsao, H W; Yen, C T

    1999-11-15

    This study introduces algorithmic complexity to measure characteristics of brain functions. The EEG of the rat was recorded with implanted electrodes. The normalized complexity value was relatively independent of data length, and it showed a simpler and easier calculation characteristic than other non-linear indexes. The complexity index revealed significant differences among awake, asleep, and anesthetized states. It may be useful in tracking short-term and long-term changes in brain functions, such as anesthetized depth, drug effects, or sleep-wakefulness.

  1. Awake GlideScope intubation in a critically ill pediatric patient.

    PubMed

    Fraser-Harris, Eva; Patel, Yash

    2012-04-01

    We report a challenging case of a 10-year-old boy with history of biventricular heart failure, pulmonary hypertension, severe asthma, and obesity with a BMI of 37. He presented to our hospital in acute decompensated heart failure. Our anesthesia team was consulted by the pediatric intensivist for urgent airway management in this rapidly deteriorating, premorbid patient. We describe here the use of the GlideScope(®) in an awake pediatric patient of ASA 4E status with a potentially difficult airway who required to remain in the seated position and thus necessitating a face-to-face approach. PMID:22268524

  2. Classification of awake, REM, and NREM from EEG via singular spectrum analysis.

    PubMed

    Mohammadi, Sara Mahvash; Enshaeifar, Shirin; Ghavami, Mohammad; Sanei, Saeid

    2015-01-01

    In this study, a single-channel electroencephalography (EEG) analysis method has been proposed for automated 3-state-sleep classification to discriminate Awake, NREM (non-rapid eye movement) and REM (rapid eye movement). For this purpose, singular spectrum analysis (SSA) is applied to automatically extract four brain rhythms: delta, theta, alpha, and beta. These subbands are then used to generate the appropriate features for sleep classification using a multi class support vector machine (M-SVM). The proposed method provided 0.79 agreement between the manual and automatic scores.

  3. Laser pulse propagation in a meter scale rubidium vapor/plasma cell in AWAKE experiment

    NASA Astrophysics Data System (ADS)

    Joulaei, A.; Moody, J.; Berti, N.; Kasparian, J.; Mirzanejhad, S.; Muggli, P.

    2016-09-01

    We present the results of numerical studies of laser pulse propagating in a 3.5 cm Rb vapor cell in the linear dispersion regime by using a 1D model and a 2D code that has been modified for our special case. The 2D simulation finally aimed at finding laser beam parameters suitable to make the Rb vapor fully ionized to obtain a uniform, 10 m-long, at least 1 mm in radius plasma in the next step for the AWAKE experiment.

  4. Acute functional reactivation of the language network during awake intraoperative brain mapping.

    PubMed

    Spena, Giannantonio; Costi, Emanuele; Panciani, Pier Paolo; Roca, Elena; Migliorati, Karol; Fontanella, Marco Maria

    2015-01-01

    Acute brain plasticity during resection of central lesions has been recently described. In the cases reported, perilesional latent networks, useful to preserve the neurological functions, were detected in asymptomatic patients. In this paper, we presented a case of acute functional reactivation (AFR) of the language network in a symptomatic patient. Tumor resection allowed to acutely restore the neurological deficit. Intraoperative direct cortical stimulation (DCS) and functional neuroimaging showed new epicentres of activation of the language network after tumor excision. DCS in awake surgery is mandatory to reveal AFR needful to improve the extent of resection preserving the quality of life.

  5. Resting state functional connectivity magnetic resonance imaging integrated with intraoperative neuronavigation for functional mapping after aborted awake craniotomy

    PubMed Central

    Batra, Prag; Bandt, S. Kathleen; Leuthardt, Eric C.

    2016-01-01

    Background: Awake craniotomy is currently the gold standard for aggressive tumor resections in eloquent cortex. However, a significant subset of patients is unable to tolerate this procedure, particularly the very young or old or those with psychiatric comorbidities, cardiopulmonary comorbidities, or obesity, among other conditions. In these cases, typical alternative procedures include biopsy alone or subtotal resection, both of which are associated with diminished surgical outcomes. Case Description: Here, we report the successful use of a preoperatively obtained resting state functional connectivity magnetic resonance imaging (MRI) integrated with intraoperative neuronavigation software in order to perform functional cortical mapping in the setting of an aborted awake craniotomy due to loss of airway. Conclusion: Resting state functional connectivity MRI integrated with intraoperative neuronavigation software can provide an alternative option for functional cortical mapping in the setting of an aborted awake craniotomy. PMID:26958419

  6. Preoperative saline-filled computed tomography thoracography for awake video-assisted thoracic surgery: report of three cases.

    PubMed

    Watanabe, Tatsuaki; Noda, Masafumi; Okazaki, Toshimasa; Tsukidate, Hisakatsu; Sato, Kota; Notsuda, Hirotsugu; Niikawa, Hiromichi; Okada, Yoshinori; Matsumura, Yuji; Kondo, Takashi

    2015-12-01

    Awake video-assisted thoracic surgery (VATS) is a therapeutic option for patients with intractable secondary spontaneous pneumothorax (SSP) complicated by impaired pulmonary function. The preoperative identification of air leak points is one of the keys to the success of this procedure. We describe how we performed saline-filled computed tomography (CT) thoracography to detect pleural fistulae in three patients with intractable SSP. Saline-filled CT thoracography showed bubble signs in two patients and an air-water level in bulla in one patient. The preoperative identification of air leak points resulted in successful awake VATS for all three patients. Our experience demonstrates that saline-filled CT thoracography is a useful diagnostic tool for SSP, especially when used in preparation for awake VATS when minimally invasive procedures are desirable. PMID:26070908

  7. Respiratory and hemodynamic outcomes following exchange extubation with laryngeal mask airway as compared to traditional awake extubation

    PubMed Central

    Suppiah, Ramanathan Kannan; Rajan, Sunil; Paul, Jerry; Kumar, Lakshmi

    2016-01-01

    Background: Traditional awake extubation leads to respiratory complications and hemodynamic response which are detrimental in neurosurgery, ENT surgery and patients with comorbidities. Aims: The primary objective was to compare the respiratory complications and hemodynamic stress response between traditional awake extubation of a endotracheal tube (ETT) and that following exchange extubation of ETT by using a laryngeal mask airway (LMA). Settings and Design: This prospective randomized study was conducted in a Tertiary Care Centre in 60 American Society of Anesthesiologists I and II patients coming for general surgery. Materials and Methods: Patients were randomized by permuted blocks into traditional awake extubation group and exchange extubation group. At the end of surgery in traditional group, awake extubation of ETT was done. In exchange group, 0.3 mg/kg propofol was administered, and the ETT was exchanged for a LMA. Awake extubation of LMA was then performed. Respiratory complications such as bucking, coughing, desaturation and the need for airway maneuvers and hemodynamic response were noted in both groups. Analysis Tools: Chi-square test, independent sample t- and paired t-tests were used as applicable. Results: Incidence of respiratory complication was 93.3% in traditional extubation while it was only 36.7% in exchange extubation group (P < 0.001). Hemodynamic response measured immediately at extubation in terms of heart rate, systolic blood pressure (BP), diastolic BP, mean arterial pressure, and rate pressure product were all significantly lesser in exchange group when compared to traditional extubation. Conclusion: Exchange extubation with LMA decreases respiratory complications and hemodynamic stress response when compared to traditional awake extubation. PMID:27212749

  8. A family of well-behaved Karmarkar spacetimes describing interior of relativistic stars

    NASA Astrophysics Data System (ADS)

    Singh, Ksh. Newton; Pant, Neeraj

    2016-10-01

    We present a family of new exact solutions for relativistic anisotropic stellar objects by considering a four-dimensional spacetime embedded in a five-dimensional pseudo Euclidean space, known as Class I solutions. These solutions are well behaved in all respects, satisfy all energy conditions, and the resulting compactness parameter is also within Buchdahl limit. The well-behaved nature of the solutions for a particular star solely depends on the index n. We have discussed the solutions in detail for the neutron star XTE J1739-285 (M=1.51M_⊙, ~R=10.9 km). For this particular star, the solution is well behaved in all respects for 8 ≤ n ≤ 20. However, the solutions with n<8 possess an increasing trend of the sound speed and the solutions belonging to n>20 disobey the causality condition. Further, the well-behaved nature of the solutions for PSR J0348+0432 (2.01M_⊙, ~11 km), EXO 1785-248 (1.3M_⊙, 8.85 km), and Her X-1 (0.85M_⊙, 8.1 km) are specified by the index n with limits 24 ≤ n ≤ 54, 1.5 ≤ n ≤ 4, and 0.8 ≤ n ≤ 2.7, respectively.

  9. Wearable 3-D Photoacoustic Tomography for Functional Brain Imaging in Behaving Rats

    PubMed Central

    Tang, Jianbo; Coleman, Jason E.; Dai, Xianjin; Jiang, Huabei

    2016-01-01

    Understanding the relationship between brain function and behavior remains a major challenge in neuroscience. Photoacoustic tomography (PAT) is an emerging technique that allows for noninvasive in vivo brain imaging at micrometer-millisecond spatiotemporal resolution. In this article, a novel, miniaturized 3D wearable PAT (3D-wPAT) technique is described for brain imaging in behaving rats. 3D-wPAT has three layers of fully functional acoustic transducer arrays. Phantom imaging experiments revealed that the in-plane X-Y spatial resolutions were ~200 μm for each acoustic detection layer. The functional imaging capacity of 3D-wPAT was demonstrated by mapping the cerebral oxygen saturation via multi-wavelength irradiation in behaving hyperoxic rats. In addition, we demonstrated that 3D-wPAT could be used for monitoring sensory stimulus-evoked responses in behaving rats by measuring hemodynamic responses in the primary visual cortex during visual stimulation. Together, these results show the potential of 3D-wPAT for brain study in behaving rodents. PMID:27146026

  10. Collaborating with Parents for Early School Success: The Achieving-Behaving-Caring Program

    ERIC Educational Resources Information Center

    McConaughy, Stephanie H.; Kay, Pam; Welkowitz, Julie A.; Hewitt, Kim; Fitzgerald, Martha D.

    2007-01-01

    The Achieving-Behaving-Caring (ABC) Program is an evidence-based approach to addressing the needs of elementary students at risk for emotional and behavioral difficulties and promoting successful home-school collaboration. This practical guide demonstrates how classroom teachers and parents can work together to boost individual children's…

  11. Awake and unable to move: what can perioperative practitioners do to avoid accidental awareness under general anaesthesia?

    PubMed

    Almeida, D

    2015-12-01

    I thought the last thing I would remember about my surgery was counting up to 10 ... but that didn't happen... I could hear people talking, instruments banging, the sound of my heart beat coming from the anaesthetic machine and all of a sudden, that horrible pain digging inside my body. Oh my God! I thought. I'm awake! I tried to tell someone but no sound came out of my mouth. I tried to kick my legs, shake my arms, blink, breathe... Nothing!! I couldn't move a muscle. I was paralysed and awake during my operation... I thought I was going to die!!!

  12. [Perioperative management of an obese patient complicated with sleep apnea syndrome (SAS) undergoing awake craniotomy].

    PubMed

    Komayama, Noriaki; Kamata, Kotoe; Maruyama, Takashi; Nitta, Masayuki; Muragaki, Yoshihiro; Ozaki, Makoto

    2014-10-01

    Both obesity (BMI over 30) and SAS are risks for Supper airway maintenance. We report an obese patient (BMI 33.5) with SAS who underwent awake craniotomy. Weight reduction was instructed 1 month before the operation, and the patient lost enough weight to use intraoperative MRI. Under general anesthesia, surgical pads containing 2% lidocaine with adrenaline were inserted into the nasal cavities. The patient's airway S was secured by i-gel® until dura was opened. A nasal airway was then inserted to confirm the upper airway patency and anesthetics were terminated The patient regained consciousness and started respiration. The i-gel® was removed. The nasal airway was changed to an RAE tracheal tube ; the tube was fixed above the vocal cords under bronchofiberscopic observation. Continuous positive airway pressure (CPAP) via RAE tube was started. Neither coughing nor epistaxis was observed.The RAE tube prevented glossoptosis and did not disturb speech mapping. Emergent endotracheal intubation was easily managed because the tube was close to the glottis. The RAE tube was removed and nasal CP AP was applied overnight Carefully prepared CP AP support via nasal RAE tube was practical in keeping upper airway patency for an obese patient complicated with SAS undergoing awake craniotomy.

  13. The discriminatory value of cardiorespiratory interactions in distinguishing awake from anaesthetised states: a randomised observational study.

    PubMed

    Kenwright, D A; Bernjak, A; Draegni, T; Dzeroski, S; Entwistle, M; Horvat, M; Kvandal, P; Landsverk, S A; McClintock, P V E; Musizza, B; Petrovčič, J; Raeder, J; Sheppard, L W; Smith, A F; Stankovski, T; Stefanovska, A

    2015-12-01

    Depth of anaesthesia monitors usually analyse cerebral function with or without other physiological signals; non-invasive monitoring of the measured cardiorespiratory signals alone would offer a simple, practical alternative. We aimed to investigate whether such signals, analysed with novel, non-linear dynamic methods, would distinguish between the awake and anaesthetised states. We recorded ECG, respiration, skin temperature, pulse and skin conductivity before and during general anaesthesia in 27 subjects in good cardiovascular health, randomly allocated to receive propofol or sevoflurane. Mean values, variability and dynamic interactions were determined. Respiratory rate (p = 0.0002), skin conductivity (p = 0.03) and skin temperature (p = 0.00006) changed with sevoflurane, and skin temperature (p = 0.0005) with propofol. Pulse transit time increased by 17% with sevoflurane (p = 0.02) and 11% with propofol (p = 0.007). Sevoflurane reduced the wavelet energy of heart (p = 0.0004) and respiratory (p = 0.02) rate variability at all frequencies, whereas propofol decreased only the heart rate variability below 0.021 Hz (p < 0.05). The phase coherence was reduced by both agents at frequencies below 0.145 Hz (p < 0.05), whereas the cardiorespiratory synchronisation time was increased (p < 0.05). A classification analysis based on an optimal set of discriminatory parameters distinguished with 95% success between the awake and anaesthetised states. We suggest that these results can contribute to the design of new monitors of anaesthetic depth based on cardiovascular signals alone. PMID:26350998

  14. Prolonged wakefulness alters neuronal responsiveness to local electrical stimulation of the neocortex in awake rats

    PubMed Central

    Vyazovskiy, Vladyslav V.; Olcese, Umberto; Cirelli, Chiara; Tononi, Giulio

    2012-01-01

    Summary Prolonged wakefulness or a lack of sleep lead to cognitive deficits, but little is known about the underlying cellular mechanisms. We recently found that sleep deprivation affects spontaneous neuronal activity in the neocortex of sleeping and awake rats. While it is well known that synaptic responses are modulated by ongoing cortical activity, it remains unclear whether prolonged waking affects responsiveness of cortical neurons to incoming stimuli. By applying local electrical microstimulation to the frontal area of the neocortex, we found that after a 4-hour period of waking the initial neuronal response in the contralateral frontal cortex was stronger and more synchronous, and was followed by a more profound inhibition of neuronal spiking as compared to the control condition. These changes in evoked activity suggest increased neuronal excitability and indicate that after staying awake cortical neurons become transiently bistable. We propose that some of the detrimental effects of sleep deprivation may be a result of altered neuronal responsiveness to incoming intrinsic and extrinsic inputs. PMID:23607417

  15. Detergent inhibits 70-90% of responses to intravenous endotoxin in awake sheep.

    PubMed

    Staub, N C; Longworth, K E; Serikov, V; Jerome, E H; Elsasser, T

    2001-05-01

    Sheep have reactive pulmonary intravascular macrophages, which are essential for the marked pulmonary vascular response to infusions of small quantities of endotoxin. In another species with reactive pulmonary intravascular macrophages, horses, our laboratory found that an intravenous biosafe detergent, tyloxapol, inhibited some systemic and pulmonary responses to endotoxin (Longworth KE, Smith BL, Staub NC, Steffey EP, and Serikov V. Am J Vet Res 57: 1063-1066, 1996). We determined whether the same detergent would inhibit endotoxin responses in awake sheep. In 10 awake, instrumented sheep with chronic lung lymph fistulas, we did a control experiment by intravenously infusing 1 microg/kg Escherichia coli endotoxin. One week later, we gave 40 micromol/kg tyloxapol intravenously 1-4 h before infusing the same dose of endotoxin. In these paired studies, we compared pulmonary hemodynamics, lung lymph dynamics, body temperature, circulating leukocyte concentrations, and circulating tumor necrosis factor for 6 h. In all 10 sheep, tyloxapol blocked 80-90% of the pulmonary responses and 70-90% of the systemic responses. Tyloxapol is safe, inexpensive, easy to use, and effective immediately. It may be a clinically useful approach to contravening many of the effects of endotoxemia, in humans as well as animals.

  16. Technical and Conceptual Considerations for Performing and Interpreting Functional MRI Studies in Awake Rats

    PubMed Central

    Febo, Marcelo

    2011-01-01

    Functional neuroimaging studies in rodents have the potential to provide insight into neurodevelopmental and psychiatric conditions. The strength of the technique lies in its non-invasive nature that can permit longitudinal functional studies in the same animal over its adult life. The relatively good spatial and temporal resolution and the ever-growing database on the biological and biophysical basis of the blood oxygen level dependent (BOLD) signal make it a unique technique in preclinical neuroscience research. Our laboratory has used imaging to investigate brain activation in awake rats following cocaine administration and during the presentation of lactation-associated sensory stimuli. Factors that deserve attention when planning functional magnetic resonance imaging studies in rats include technical issues, animal physiology and interpretability of the resulting data. The present review discusses the pros and cons of animal imaging with a particular focus on the technical aspects of studies with awake rats. Overall, the benefits of the technique outweigh its limitations and the rapidly evolving methods will open the way for more laboratories to employ the technique in neuroscience research. PMID:21808625

  17. Indirect self-modulation instability measurement concept for the AWAKE proton beam

    NASA Astrophysics Data System (ADS)

    Turner, M.; Petrenko, A.; Biskup, B.; Burger, S.; Gschwendtner, E.; Lotov, K. V.; Mazzoni, S.; Vincke, H.

    2016-09-01

    AWAKE, the Advanced Proton-Driven Plasma Wakefield Acceleration Experiment, is a proof-of-principle R&D experiment at CERN using a 400 GeV / c proton beam from the CERN SPS (longitudinal beam size σz = 12 cm) which will be sent into a 10 m long plasma section with a nominal density of ≈ 7 ×1014 atoms /cm3 (plasma wavelength λp = 1.2 mm). In this paper we show that by measuring the time integrated transverse profile of the proton bunch at two locations downstream of the AWAKE plasma, information about the occurrence of the self-modulation instability (SMI) can be inferred. In particular we show that measuring defocused protons with an angle of 1 mrad corresponds to having electric fields in the order of GV/m and fully developed self-modulation of the proton bunch. Additionally, by measuring the defocused beam edge of the self-modulated bunch, information about the growth rate of the instability can be extracted. If hosing instability occurs, it could be detected by measuring a non-uniform defocused beam shape with changing radius. Using a 1 mm thick Chromox scintillation screen for imaging of the self-modulated proton bunch, an edge resolution of 0.6 mm and hence an SMI saturation point resolution of 1.2 m can be achieved.

  18. Status of the proton and electron transfer lines for the AWAKE Experiment at CERN

    NASA Astrophysics Data System (ADS)

    Schmidt, J. S.; Bauche, J.; Biskup, B.; Bracco, C.; Doebert, S.; Goddard, B.; Gschwendtner, E.; Jensen, L. K.; Jones, O. R.; Mazzoni, S.; Meddahi, M.; Pepitone, K.; Petrenko, A.; Velotti, F. M.; Vorozhtsov, A.

    2016-09-01

    The AWAKE project at CERN is planned to study proton driven plasma wakefield acceleration with an externally injected electron beam. Therefore two transfer lines are being designed in order to provide the proton beam from the SPS and the electron beam from an RF gun to the plasma cell. The commissioning of the proton line will take place in 2016 for the first phase of the experiment, which is focused on the self-modulation of a 12 cm long proton bunch in the plasma. The electron line will be added for the second phase of AWAKE in 2017, when the wakefield will be probed with an electron beam of 10-20 MeV/c. The challenge for these transfer lines lies in the parallel operation of the proton, electron and laser beam used to ionize the plasma and seed the self-modulation. These beams, of different characteristics, need to be synchronized and positioned for optimized injection conditions into the wakefield. This task requires great flexibility in the transfer line optics. The status of these designs will be presented in this paper.

  19. The stimulus-evoked population response in visual cortex of awake monkey is a propagating wave.

    PubMed

    Muller, Lyle; Reynaud, Alexandre; Chavane, Frédéric; Destexhe, Alain

    2014-04-28

    Propagating waves occur in many excitable media and were recently found in neural systems from retina to neocortex. While propagating waves are clearly present under anaesthesia, whether they also appear during awake and conscious states remains unclear. One possibility is that these waves are systematically missed in trial-averaged data, due to variability. Here we present a method for detecting propagating waves in noisy multichannel recordings. Applying this method to single-trial voltage-sensitive dye imaging data, we show that the stimulus-evoked population response in primary visual cortex of the awake monkey propagates as a travelling wave, with consistent dynamics across trials. A network model suggests that this reliability is the hallmark of the horizontal fibre network of superficial cortical layers. Propagating waves with similar properties occur independently in secondary visual cortex, but maintain precise phase relations with the waves in primary visual cortex. These results show that, in response to a visual stimulus, propagating waves are systematically evoked in several visual areas, generating a consistent spatiotemporal frame for further neuronal interactions.

  20. Language mapping with verbs and sentences in awake surgery: a review.

    PubMed

    Rofes, Adrià; Miceli, Gabriele

    2014-06-01

    Intraoperative language mapping in awake surgery is typically conducted by asking the patient to produce automatic speech and to name objects. These tasks might not map language with sufficient accuracy, as some linguistic processes can only be triggered by tasks that use verbs and sentences. Verb and sentence processing tasks are currently used during surgery, albeit sparsely. Medline, PubMed, and Web of Science records were searched to retrieve studies focused on language mapping with verbs/sentences in awake surgery. We review the tasks reported in the published literature, spell out the language processes assessed by each task, list the cortical and subcortical regions whose stimulation inhibited language processing, and consider the types of errors elicited by stimulation in each region. We argue that using verb tasks allows a more thorough evaluation of language functions. We also argue that verb tasks are preferable to object naming tasks in the case of frontal lesions, as lesion and neuroimaging data demonstrate that these regions play a critical role in verb and sentence processing. We discuss the clinical value of these tasks and the current limitations of the procedure, and provide some guidelines for their development. Future research should aim toward a differentiated approach to language mapping - one that includes the administration of standardized and customizable tests and the use of longitudinal neurocognitive follow-up studies. Further work will allow researchers and clinicians to understand brain and language correlates and to improve the current surgical practice.

  1. Membrane Potential Dynamics of Spontaneous and Visually Evoked Gamma Activity in V1 of Awake Mice

    PubMed Central

    Perrenoud, Quentin; Pennartz, Cyriel M. A.; Gentet, Luc J.

    2016-01-01

    Cortical gamma activity (30–80 Hz) is believed to play important functions in neural computation and arises from the interplay of parvalbumin-expressing interneurons (PV) and pyramidal cells (PYRs). However, the subthreshold dynamics underlying its emergence in the cortex of awake animals remain unclear. Here, we characterized the intracellular dynamics of PVs and PYRs during spontaneous and visually evoked gamma activity in layers 2/3 of V1 of awake mice using targeted patch-clamp recordings and synchronous local field potentials (LFPs). Strong gamma activity patterned in short bouts (one to three cycles), occurred when PVs and PYRs were depolarizing and entrained their membrane potential dynamics regardless of the presence of visual stimulation. PV firing phase locked unconditionally to gamma activity. However, PYRs only phase locked to visually evoked gamma bouts. Taken together, our results indicate that gamma activity corresponds to short pulses of correlated background synaptic activity synchronizing the output of cortical neurons depending on external sensory drive. PMID:26890123

  2. No short-term effects of digital mobile radio telephone on the awake human electroencephalogram

    SciTech Connect

    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} 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.

  3. Disrupting neural activity related to awake-state sharp wave-ripple complexes prevents hippocampal learning

    PubMed Central

    Nokia, Miriam S.; Mikkonen, Jarno E.; Penttonen, Markku; Wikgren, Jan

    2012-01-01

    Oscillations in hippocampal local-field potentials (LFPs) reflect the crucial involvement of the hippocampus in memory trace formation: theta (4–8 Hz) oscillations and ripples (~200 Hz) occurring during sharp waves are thought to mediate encoding and consolidation, respectively. During sharp wave-ripple complexes (SPW-Rs), hippocampal cell firing closely follows the pattern that took place during the initial experience, most likely reflecting replay of that event. Disrupting hippocampal ripples using electrical stimulation either during training in awake animals or during sleep after training retards spatial learning. Here, adult rabbits were trained in trace eyeblink conditioning, a hippocampus-dependent associative learning task. A bright light was presented to the animals during the inter-trial interval (ITI), when awake, either during SPW-Rs or irrespective of their neural state. Learning was particularly poor when the light was presented following SPW-Rs. While the light did not disrupt the ripple itself, it elicited a theta-band oscillation, a state that does not usually coincide with SPW-Rs. Thus, it seems that consolidation depends on neuronal activity within and beyond the hippocampus taking place immediately after, but by no means limited to, hippocampal SPW-Rs. PMID:23316148

  4. Novel method for functional brain imaging in awake minimally restrained rats.

    PubMed

    Chang, Pei-Ching; Procissi, Daniel; Bao, Qiyuan; Centeno, Maria Virginia; Baria, Alex; Apkarian, A Vania

    2016-07-01

    Functional magnetic resonance imaging (fMRI) in rodents holds great promise for advancing our knowledge about human brain function. However, the use of anesthetics to immobilize rodents during fMRI experiments has restricted the type of questions that can be addressed using this technique. Here we describe an innovative procedure to train rats to be constrained without the need of any anesthesia during the whole procedure. We show that with 8-10 days of acclimation rats can be conscious and remain still during fMRI experiments under minimal stress. In addition, we provide fMRI results of conscious rodents in a variety of commonly used fMRI experimental paradigms, and we demonstrate the improved quality of these scans by comparing results when the same rodents were scanned under anesthesia. We confirm that the awake scanning procedure permits an improved evaluation of brain networks and brain response to external stimuli with minimal movement artifact. The present study further advances the field of fMRI in awake rodents, which provide more direct, forward and reverse, translational opportunities regarding brain functional correspondences between human and rodent research.

  5. A novel tablet computer platform for advanced language mapping during awake craniotomy procedures.

    PubMed

    Morrison, Melanie A; Tam, Fred; Garavaglia, Marco M; Golestanirad, Laleh; Hare, Gregory M T; Cusimano, Michael D; Schweizer, Tom A; Das, Sunit; Graham, Simon J

    2016-04-01

    A computerized platform has been developed to enhance behavioral testing during intraoperative language mapping in awake craniotomy procedures. The system is uniquely compatible with the environmental demands of both the operating room and preoperative functional MRI (fMRI), thus providing standardized testing toward improving spatial agreement between the 2 brain mapping techniques. Details of the platform architecture, its advantages over traditional testing methods, and its use for language mapping are described. Four illustrative cases demonstrate the efficacy of using the testing platform to administer sophisticated language paradigms, and the spatial agreement between intraoperative mapping and preoperative fMRI results. The testing platform substantially improved the ability of the surgeon to detect and characterize language deficits. Use of a written word generation task to assess language production helped confirm areas of speech apraxia and speech arrest that were inadequately characterized or missed with the use of traditional paradigms, respectively. Preoperative fMRI of the analogous writing task was also assistive, displaying excellent spatial agreement with intraoperative mapping in all 4 cases. Sole use of traditional testing paradigms can be limiting during awake craniotomy procedures. Comprehensive assessment of language function will require additional use of more sophisticated and ecologically valid testing paradigms. The platform presented here provides a means to do so.

  6. Intact skull chronic windows for mesoscopic wide-field imaging in awake mice

    PubMed Central

    Silasi, Gergely; Xiao, Dongsheng; Vanni, Matthieu P.; Chen, Andrew C. N.; Murphy, Timothy H.

    2016-01-01

    Background Craniotomy-based window implants are commonly used for microscopic imaging, in head-fixed rodents, however their field of view is typically small and incompatible with mesoscopic functional mapping of cortex. New Method We describe a reproducible and simple procedure for chronic through-bone wide-field imaging in awake head-fixed mice providing stable optical access for chronic imaging over large areas of the cortex for months. Results The preparation is produced by applying clear-drying dental cement to the intact mouse skull, followed by a glass coverslip to create a partially transparent imaging surface. Surgery time takes about 30 minutes. A single set-screw provides a stable means of attachment for mesoscale assessment without obscuring the cortical field of view. Comparison with Existing Methods We demonstrate the utility of this method by showing seed-pixel functional connectivity maps generated from spontaneous cortical activity of GCAMP6 signals in both awake and anesthetized mice. Conclusions We propose that the intact skull preparation described here may be used for most longitudinal studies that do not require micron scale resolution and where cortical neural or vascular signals are recorded with intrinsic sensors. PMID:27102043

  7. Episodic-like memory trace in awake replay of hippocampal place cell activity sequences

    PubMed Central

    Takahashi, Susumu

    2015-01-01

    Episodic memory retrieval of events at a specific place and time is effective for future planning. Sequential reactivation of the hippocampal place cells along familiar paths while the animal pauses is well suited to such a memory retrieval process. It is, however, unknown whether this awake replay represents events occurring along the path. Using a subtask switching protocol in which the animal experienced three subtasks as ‘what’ information in a maze, I here show that the replay represents a trial type, consisting of path and subtask, in terms of neuronal firing timings and rates. The actual trial type to be rewarded could only be reliably predicted from replays that occurred at the decision point. This trial-type representation implies that not only ‘where and when’ but also ‘what’ information is contained in the replay. This result supports the view that awake replay is an episodic-like memory retrieval process. DOI: http://dx.doi.org/10.7554/eLife.08105.001 PMID:26481131

  8. The linearity and selectivity of neuronal responses in awake visual cortex

    PubMed Central

    Chen, Yao; Anand, Sanjiv; Martinez-Conde, Susana; Macknik, Stephen L.; Bereshpolova, Yulia; Swadlow, Harvey A.; Alonso, Jose-Manuel

    2011-01-01

    Neurons in primary visual cortex (V1) are frequently classified based on their response linearity: the extent in which their visual responses to drifting gratings resemble a linear replica of the stimulus. This classification is supported by the finding that response linearity is bimodally distributed across neurons in area V1 of anesthetized animals. However, recent studies suggest that such bimodal distribution may not reflect two neuronal types but a nonlinear relationship between the membrane potential and the spike output. A main limitation of these previous studies is that they measured response linearity in anesthetized animals, where the distance between the neuronal membrane potential and spike threshold is artificially increased by anesthesia. Here, we measured V1 response linearity in the awake brain and its correlation with the neuronal spontaneous firing rate, which is related to the distance between membrane potential and threshold. Our results demonstrate that response linearity is bimodally distributed in awake V1 but that it is poorly correlated with spontaneous firing rate. In contrast, the spontaneous firing rate is best correlated to the response selectivity and response latency to stimuli. PMID:19761345

  9. The stimulus-evoked population response in visual cortex of awake monkey is a propagating wave

    PubMed Central

    Muller, Lyle; Reynaud, Alexandre; Chavane, Frédéric; Destexhe, Alain

    2014-01-01

    Propagating waves occur in many excitable media and were recently found in neural systems from retina to neocortex. While propagating waves are clearly present under anaesthesia, whether they also appear during awake and conscious states remains unclear. One possibility is that these waves are systematically missed in trial-averaged data, due to variability. Here we present a method for detecting propagating waves in noisy multichannel recordings. Applying this method to single-trial voltage-sensitive dye imaging data, we show that the stimulus-evoked population response in primary visual cortex of the awake monkey propagates as a travelling wave, with consistent dynamics across trials. A network model suggests that this reliability is the hallmark of the horizontal fibre network of superficial cortical layers. Propagating waves with similar properties occur independently in secondary visual cortex, but maintain precise phase relations with the waves in primary visual cortex. These results show that, in response to a visual stimulus, propagating waves are systematically evoked in several visual areas, generating a consistent spatiotemporal frame for further neuronal interactions. PMID:24770473

  10. Influence of hemorrhage on adrenal secretion, blood glucose and serum insulin in the awake pig.

    PubMed Central

    Carey, L C; Curtin, R; Sapira, J D

    1976-01-01

    A study was performed to quantitate the adrenal medullary and cortical response to hemorrhage in awake animals bled at different rates and to relate these responses to simultaneous changes in blood glucose and serum insulin. A series of awake pigs were bled either slowly or rapidly of 30% of their calculated blood volume. Infusions of exogenous epinephrine were performed in an additional series of unbled animals and infusions of epinephrine plus hydrocortisone were similarly performed in an additonal series. Increase in blood glucose and epinephrine secretion rate following hemorrhage were found to be significantly dependent upon the rate of initial hemorrhage. Cortisol secretion was found to rise significantly during and following hemorrhage in both rapidly and slowly bled animals. Serum insulin levels remained at baseline levels during shock, despite the presence of significant hyperglycemia. In unbled animals infused with epinephrine at rates comparable to those measured in shock, elevations in blood glucose were markedly lower, shifting to the right of the dose-response curve during hemorrhage. Simultaneous infusions of cortisol and epinephrine resulted in a dose-response curve which did not differ significantly from that following infusion of epinephrine alone. Images Fig. 2. PMID:1247317

  11. A novel tablet computer platform for advanced language mapping during awake craniotomy procedures.

    PubMed

    Morrison, Melanie A; Tam, Fred; Garavaglia, Marco M; Golestanirad, Laleh; Hare, Gregory M T; Cusimano, Michael D; Schweizer, Tom A; Das, Sunit; Graham, Simon J

    2016-04-01

    A computerized platform has been developed to enhance behavioral testing during intraoperative language mapping in awake craniotomy procedures. The system is uniquely compatible with the environmental demands of both the operating room and preoperative functional MRI (fMRI), thus providing standardized testing toward improving spatial agreement between the 2 brain mapping techniques. Details of the platform architecture, its advantages over traditional testing methods, and its use for language mapping are described. Four illustrative cases demonstrate the efficacy of using the testing platform to administer sophisticated language paradigms, and the spatial agreement between intraoperative mapping and preoperative fMRI results. The testing platform substantially improved the ability of the surgeon to detect and characterize language deficits. Use of a written word generation task to assess language production helped confirm areas of speech apraxia and speech arrest that were inadequately characterized or missed with the use of traditional paradigms, respectively. Preoperative fMRI of the analogous writing task was also assistive, displaying excellent spatial agreement with intraoperative mapping in all 4 cases. Sole use of traditional testing paradigms can be limiting during awake craniotomy procedures. Comprehensive assessment of language function will require additional use of more sophisticated and ecologically valid testing paradigms. The platform presented here provides a means to do so. PMID:26473779

  12. Distinct spatiotemporal activity in principal neurons of the mouse olfactory bulb in anesthetized and awake states

    PubMed Central

    Blauvelt, David G.; Sato, Tomokazu F.; Wienisch, Martin; Murthy, Venkatesh N.

    2013-01-01

    The acquisition of olfactory information and its early processing in mammals are modulated by brain states through sniffing behavior and neural feedback. We imaged the spatiotemporal pattern of odor-evoked activity in a population of output neurons (mitral/tufted cells, MTCs) in the olfactory bulb (OB) of head-restrained mice expressing a genetically-encoded calcium indicator. The temporal dynamics of MTC population activity were relatively simple in anesthetized animals, but were highly variable in awake animals. However, the apparently irregular activity in awake animals could be predicted well using sniff timing measured externally, or inferred through fluctuations in the global responses of MTC population even without explicit knowledge of sniff times. The overall spatial pattern of activity was conserved across states, but odor responses had a diffuse spatial component in anesthetized mice that was less prominent during wakefulness. Multi-photon microscopy indicated that MTC lateral dendrites were the likely source of spatially disperse responses in the anesthetized animal. Our data demonstrate that the temporal and spatial dynamics of MTCs can be significantly modulated by behavioral state, and that the ensemble activity of MTCs can provide information about sniff timing to downstream circuits to help decode odor responses. PMID:23543674

  13. Ultra-minimally invasive cardiac surgery: robotic surgery and awake CABG.

    PubMed

    Ishikawa, Norihiko; Watanabe, Go

    2015-01-01

    The recognition of the significant advantages of minimizing surgical trauma has resulted in the development of minimally invasive surgical procedures. Endoscopic surgery confers the benefits of minimally invasive surgery upon patients, and surgical robots have enhanced the ability and precision of surgeons. Consequently, technological advances have facilitated totally endoscopic robotic cardiac surgery, which has allowed surgeons to operate endoscopically, rather than through a median sternotomy, during cardiac surgery. Thus, repairs for structural heart conditions, including mitral valve plasty, atrial septal defect closure, multivessel minimally invasive direct coronary artery bypass grafting and totally endoscopic coronary artery bypass graft surgery (CABG), can be totally endoscopic. On the other hand, general anesthesia remains a risk in patients who have severe carotid artery stenosis before surgery, as well as in those with a history of severe cerebral infarction or respiratory failure. In this study, the potential of a new awake CABG protocol using only epidural anesthesia was investigated for realizing day surgery and was found to be a promising modality for ultra-minimally invasive cardiac surgery. We herein review robot-assisted cardiac surgery and awake off-pump coronary artery bypass grafting as ultra-minimally invasive cardiac surgeries. PMID:25274467

  14. [(11)C]Raclopride binding in the striatum of minimally restrained and free-walking awake mice in a positron emission tomography study.

    PubMed

    Takuwa, Hiroyuki; Maeda, Jun; Ikoma, Yoko; Tokunaga, Masaki; Wakizaka, Hidekatsu; Uchida, Shouko; Kanno, Iwao; Taniguchi, Junko; Ito, Hiroshi; Higuchi, Makoto

    2015-12-01

    Anesthesia and restraint stress have profound impacts on brain functions, including neural activity and cerebrovascular function, possibly influencing functional and neurochemical positron emission tomography (PET) imaging data. For circumventing this effect, we developed an experimental system enabling PET imaging of free-walking awake mice with minimal restraints by fixing the head to a holder. The applicability of this system was investigated by performing PET imaging of D2 dopamine receptors with [(11)C]raclopride under the following three different conditions: (1) free-walking awake state; (2) 1.5% isoflurane anesthesia; and (3) whole-body restraint without anesthesia. [(11)C]raclopride binding potential (BP(ND)) values under isoflurane anesthesia and restrained awake state were significantly lower than under free-walking awake state (P < 0.01). Heart rates in restrained awake mice were significantly higher than those in free-walking awake mice (P < 0.01), suggesting that free-walking awake state minimized restraint stress during the PET scan. [(11)C] raclopride-PET with methamphetamine (METH) injection was also performed in awake and anesthetized mice. METH-induced reduction of [(11)C]raclopride BP(ND) in anesthetized mice showed a trend to be less than that in free-walking awake mice, implying that pharmacological modulation of dopaminergic transmissions could be sensitively captured by PET imaging of free-walking awake mice. We concluded that our system is of utility as an in vivo assaying platform for studies of brain functions and neurotransmission elements in small animals, such as those modeling neuropsychiatric disorders.

  15. Speaking Freely

    ERIC Educational Resources Information Center

    Watson, Jamal Eric

    2012-01-01

    Ask Princeton University's Dr. Cornel West about his views on Black History Month, and somehow the conversation ends up with a sharp critique of the Obama administration. This article profiles West who pulls no punches when it comes to his advocacy for impoverished Americans. For more than three decades, the 58-year-old philosopher has combined…

  16. Simultaneous recording of the field-EPSP as well as the population spike in the CA1 region in freely moving rats by using a fixed "double"-recording electrode.

    PubMed

    Scherf, Thomas; Frey, Julietta U; Frey, Sabine

    2010-04-30

    The recording of field potentials in freely moving rats is a very appropriate and commonly used method to describe changes in cellular mechanisms underlying synaptic plasticity. Recently, we introduced a method for the simultaneous recording of both the field-EPSP as well as the population spike in the dentate gyrus of freely moving rats. We used self-made "double"-recording electrodes, consisting of two wires straighten together with a constant distance between both tips. This method was now further developed to obtain stable long-term recordings of CA1 field potentials. Rats were chronically implanted with a bipolar recording electrode; one tip of which reached the stratum radiatum to record the field-EPSP, the other tip was lowered into the stratum pyramidale of the same neuron population to record the population spike by stimulation of the contralateral CA3 (cCA3). In such prepared rats, simultaneously recorded field-EPSP as well as the population spike where thus obtained from their places of generation in a very reliable manner. This kind of preparation allowed a better standardization of stimulation intensities between different animals and stable electrophysiological recordings of both CA1-potentials over a time period of at least 24h in freely behaving animals. Furthermore, primed burst stimulation of the cCA3 (a single biphasic priming pulse was followed by a burst of 10 pulses (frequency of 100 Hz) 190 ms later; pulse duration per half-wave: 0.1 ms) resulted in an early-LTP of both measured parameters, the field-EPSP and the population spike in the CA1 region of freely moving rats.

  17. REAL-TIME MEASUREMENT OF AIRWAY RESPONSES TO SULOFUR DIOXIDE (SO2) IN AN INTACT, AWAKE GUINEA PIG MODEL

    EPA Science Inventory

    Real-time measurment of airway responses to Sulfur Dioxide (SO2) in an intact, awake guinea pig model. J Stanek1,2, Q Krantz2, J Nolan2, D Winsett2, W Watkinson2, and D Costa2. 1College of Veterinary Medicine, NCSU, Raleigh, NC, USA; 2Pulmonary Toxicology Branch, ETD, NHEERL, US...

  18. Coding of Electric Pulse Trains Presented through Cochlear Implants in the Auditory Midbrain of Awake Rabbit: Comparison with Anesthetized Preparations

    PubMed Central

    Hancock, Kenneth E.; Nam, Sung-Il; Delgutte, Bertrand

    2014-01-01

    Cochlear implant (CI) listeners show limits at high frequencies in tasks involving temporal processing such as rate pitch and interaural time difference discrimination. Similar limits have been observed in neural responses to electric stimulation in animals with CI; however, the upper limit of temporal coding of electric pulse train stimuli in the inferior colliculus (IC) of anesthetized animals is lower than the perceptual limit. We hypothesize that the upper limit of temporal neural coding has been underestimated in previous studies due to the confound of anesthesia. To test this hypothesis, we developed a chronic, awake rabbit preparation for single-unit studies of IC neurons with electric stimulation through CI. Stimuli were periodic trains of biphasic pulses with rates varying from 20 to 1280 pulses per second. We found that IC neurons in awake rabbits showed higher spontaneous activity and greater sustained responses, both excitatory and suppressive, at high pulse rates. Maximum pulse rates that elicited synchronized responses were approximately two times higher in awake rabbits than in earlier studies with anesthetized animals. Here, we demonstrate directly that anesthesia is a major factor underlying these differences by monitoring the responses of single units in one rabbit before and after injection of an ultra-short-acting barbiturate. In general, the physiological rate limits of IC neurons in the awake rabbit are more consistent with the psychophysical limits in human CI subjects compared with limits from anesthetized animals. PMID:24381283

  19. Concentration of frequencies of trapped waves in problems on freely floating bodies

    SciTech Connect

    Nazarov, Sergei A

    2012-09-30

    It is shown that by choosing the shape of two identical bodies floating freely in a channel with symmetric cross-section it is possible to form any pre-assigned number of linearly independent trapped waves (localized solutions). Bibliography: 27 titles.

  20. 34 CFR 300.701 - Outlying areas, freely associated States, and the Secretary of the Interior.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... States—(1) Funds reserved. From the amount appropriated for any fiscal year under section 611(i) of the... State received for fiscal year 2003 under Part B of the Act, but only if the freely associated State— (A... Public Law 95-134, permitting the consolidation of grants by the outlying areas, do not apply to...

  1. Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

    PubMed

    Waaramaa, Teija; Palo, Pertti; Kankare, Elina

    2015-12-01

    Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions.

  2. Emotions in freely varying and mono-pitched vowels, acoustic and EGG analyses.

    PubMed

    Waaramaa, Teija; Palo, Pertti; Kankare, Elina

    2015-12-01

    Vocal emotions are expressed either by speech or singing. The difference is that in singing the pitch is predetermined while in speech it may vary freely. It was of interest to study whether there were voice quality differences between freely varying and mono-pitched vowels expressed by professional actors. Given their profession, actors have to be able to express emotions both by speech and singing. Electroglottogram and acoustic analyses of emotional utterances embedded in expressions of freely varying vowels [a:], [i:], [u:] (96 samples) and mono-pitched protracted vowels (96 samples) were studied. Contact quotient (CQEGG) was calculated using 35%, 55%, and 80% threshold levels. Three different threshold levels were used in order to evaluate their effects on emotions. Genders were studied separately. The results suggested significant gender differences for CQEGG 80% threshold level. SPL, CQEGG, and F4 were used to convey emotions, but to a lesser degree, when F0 was predetermined. Moreover, females showed fewer significant variations than males. Both genders used more hypofunctional phonation type in mono-pitched utterances than in the expressions with freely varying pitch. The present material warrants further study of the interplay between CQEGG threshold levels and formant frequencies, and listening tests to investigate the perceptual value of the mono-pitched vowels in the communication of emotions. PMID:24998780

  3. Spontaneous and repetitive cardiac slowdown in the freely moving spiny lobster, Panulirus japonicus.

    PubMed

    Yazawa, T; Katsuyama, T

    2001-12-01

    The fluctuation of heartbeat interval was investigated to assess cardio-regulatory nervous function in freely moving spiny lobsters. This was performed by time series analysis of the heartbeat interval recorded from restrained animals, freely moving animals, and isolated hearts. The heart rate of freely moving animals exhibited on/off switching: i.e., an elevated and maintained rate was repetitively interrupted by periods of decreased rate. Each period was initiated by a sudden decrease in rate and was terminated by an exponential return to normal activity. In order to explain this characteristic change in heart rate, we have constructed a neurotransmitter release-reuptake model for such bi-stable activity of cardio-regulatory nerves. The model was successful in reproducing the characteristic observed fluctuation. In freely moving animals, the brain seems to regulate the heart through the inhibitory nerve in an "on/off" manner. In the hearts of restrained animals and isolated hearts, the heart rate exhibited white-noise like fluctuation. This implies that stress impairs the normal bi-stable regulatory mode. PMID:11800038

  4. Motion quantification during multi-photon functional imaging in behaving animals

    PubMed Central

    Kong, Lingjie; Little, Justin P.; Cui, Meng

    2016-01-01

    Functional imaging in behaving animals is essential to understanding brain function. However, artifacts resulting from animal motion, including locomotion, can severely corrupt functional measurements. To dampen tissue motion, we designed a new optical window with minimal optical aberrations. Using the newly developed high-speed continuous volumetric imaging system based on an optical phase-locked ultrasound lens, we quantified motion of the cerebral cortex and hippocampal surface during two-photon functional imaging in behaving mice. We find that the out-of-plane motion is generally greater than the axial dimension of the point-spread-function during mouse locomotion, which indicates that high-speed continuous volumetric imaging is necessary to minimize motion artifacts.

  5. Motion quantification during multi-photon functional imaging in behaving animals

    PubMed Central

    Kong, Lingjie; Little, Justin P.; Cui, Meng

    2016-01-01

    Functional imaging in behaving animals is essential to understanding brain function. However, artifacts resulting from animal motion, including locomotion, can severely corrupt functional measurements. To dampen tissue motion, we designed a new optical window with minimal optical aberrations. Using the newly developed high-speed continuous volumetric imaging system based on an optical phase-locked ultrasound lens, we quantified motion of the cerebral cortex and hippocampal surface during two-photon functional imaging in behaving mice. We find that the out-of-plane motion is generally greater than the axial dimension of the point-spread-function during mouse locomotion, which indicates that high-speed continuous volumetric imaging is necessary to minimize motion artifacts. PMID:27699129

  6. Epidural anaesthesia through caudal catheters for inguinal herniotomies in awake ex-premature babies.

    PubMed

    Peutrell, J M; Hughes, D G

    1993-02-01

    Ex-premature babies are at risk of apnoea after surgery. Regional anaesthesia has been used as an alternative to general anaesthesia for some surgical procedures in the belief that it may be safer. However, single dose caudal epidural and subarachnoid anaesthetics have a duration of action which may be insufficient for some operations. The level and duration of anaesthesia can be extended if local anaesthetic is given through an epidural catheter. In addition, the dose needed to provide adequate anaesthesia may be lower because the local anaesthetic is given at an appropriate segmental level. We report our experience of caudal epidural anaesthesia in nine, awake ex-premature babies who were having inguinal herniotomies. The anaesthesia was excellent in six babies. Two babies cried briefly with peritoneal or spermatic cord traction. One other baby needed supplementation with nitrous oxide in oxygen in order to complete the surgery. The majority of babies slept throughout surgery. There were no reported postoperative complications.

  7. Neurons Differentiated from Transplanted Stem Cells Respond Functionally to Acoustic Stimuli in the Awake Monkey Brain.

    PubMed

    Wei, Jing-Kuan; Wang, Wen-Chao; Zhai, Rong-Wei; Zhang, Yu-Hua; Yang, Shang-Chuan; Rizak, Joshua; Li, Ling; Xu, Li-Qi; Liu, Li; Pan, Ming-Ke; Hu, Ying-Zhou; Ghanemi, Abdelaziz; Wu, Jing; Yang, Li-Chuan; Li, Hao; Lv, Long-Bao; Li, Jia-Li; Yao, Yong-Gang; Xu, Lin; Feng, Xiao-Li; Yin, Yong; Qin, Dong-Dong; Hu, Xin-Tian; Wang, Zheng-Bo

    2016-07-26

    Here, we examine whether neurons differentiated from transplanted stem cells can integrate into the host neural network and function in awake animals, a goal of transplanted stem cell therapy in the brain. We have developed a technique in which a small "hole" is created in the inferior colliculus (IC) of rhesus monkeys, then stem cells are transplanted in situ to allow for investigation of their integration into the auditory neural network. We found that some transplanted cells differentiated into mature neurons and formed synaptic input/output connections with the host neurons. In addition, c-Fos expression increased significantly in the cells after acoustic stimulation, and multichannel recordings indicated IC specific tuning activities in response to auditory stimulation. These results suggest that the transplanted cells have the potential to functionally integrate into the host neural network.

  8. Statistical Modeling and Analysis of Laser-Evoked Potentials of Electrocorticogram Recordings from Awake Humans

    PubMed Central

    Chen, Zhe; Ohara, Shinji; Cao, Jianting; Vialatte, François; Lenz, Fred A.; Cichocki, Andrzej

    2007-01-01

    This article is devoted to statistical modeling and analysis of electrocorticogram (ECoG) signals induced by painful cutaneous laser stimuli, which were recorded from implanted electrodes in awake humans. Specifically, with statistical tools of factor analysis and independent component analysis, the pain-induced laser-evoked potentials (LEPs) were extracted and investigated under different controlled conditions. With the help of wavelet analysis, quantitative and qualitative analyses were conducted regarding the LEPs' attributes of power, amplitude, and latency, in both averaging and single-trial experiments. Statistical hypothesis tests were also applied in various experimental setups. Experimental results reported herein also confirm previous findings in the neurophysiology literature. In addition, single-trial analysis has also revealed many new observations that might be interesting to the neuroscientists or clinical neurophysiologists. These promising results show convincing validation that advanced signal processing and statistical analysis may open new avenues for future studies of such ECoG or other relevant biomedical recordings. PMID:18369410

  9. Endocytic structures and synaptic vesicle recycling at a central synapse in awake rats.

    PubMed

    Körber, Christoph; Horstmann, Heinz; Sätzler, Kurt; Kuner, Thomas

    2012-12-01

    The synaptic vesicle (SV) cycle has been studied extensively in cultured cells and slice preparations, but not much is known about the roles and relative contributions of endocytic pathways and mechanisms of SV recycling in vivo, under physiological patterns of activity. We employed horseradish peroxidase (HRP) as an in vivo marker of endocytosis at the calyx of Held synapse in the awake rat. Ex vivo serial section scanning electron microscopy and 3D reconstructions revealed two categories of labelled structures: HRP-filled SVs and large cisternal endosomes. Inhibition of adaptor protein complexes 1 and 3 (AP-1, AP-3) by in vivo application of Brefeldin A (BFA) disrupted endosomal SV budding while SV recycling via clathrin-mediated endocytosis (CME) remained unaffected. In conclusion, our study establishes cisternal endosomes as an intermediate of the SV cycle and reveals CME and endosomal budding as the predominant mechanisms of SV recycling in a tonically active central synapse in vivo.

  10. The Dutch Linguistic Intraoperative Protocol: a valid linguistic approach to awake brain surgery.

    PubMed

    De Witte, E; Satoer, D; Robert, E; Colle, H; Verheyen, S; Visch-Brink, E; Mariën, P

    2015-01-01

    Intraoperative direct electrical stimulation (DES) is increasingly used in patients operated on for tumours in eloquent areas. Although a positive impact of DES on postoperative linguistic outcome is generally advocated, information about the neurolinguistic methods applied in awake surgery is scarce. We developed for the first time a standardised Dutch linguistic test battery (measuring phonology, semantics, syntax) to reliably identify the critical language zones in detail. A normative study was carried out in a control group of 250 native Dutch-speaking healthy adults. In addition, the clinical application of the Dutch Linguistic Intraoperative Protocol (DuLIP) was demonstrated by means of anatomo-functional models and five case studies. A set of DuLIP tests was selected for each patient depending on the tumour location and degree of linguistic impairment. DuLIP is a valid test battery for pre-, intraoperative and postoperative language testing and facilitates intraoperative mapping of eloquent language regions that are variably located.

  11. The Dutch Linguistic Intraoperative Protocol: a valid linguistic approach to awake brain surgery.

    PubMed

    De Witte, E; Satoer, D; Robert, E; Colle, H; Verheyen, S; Visch-Brink, E; Mariën, P

    2015-01-01

    Intraoperative direct electrical stimulation (DES) is increasingly used in patients operated on for tumours in eloquent areas. Although a positive impact of DES on postoperative linguistic outcome is generally advocated, information about the neurolinguistic methods applied in awake surgery is scarce. We developed for the first time a standardised Dutch linguistic test battery (measuring phonology, semantics, syntax) to reliably identify the critical language zones in detail. A normative study was carried out in a control group of 250 native Dutch-speaking healthy adults. In addition, the clinical application of the Dutch Linguistic Intraoperative Protocol (DuLIP) was demonstrated by means of anatomo-functional models and five case studies. A set of DuLIP tests was selected for each patient depending on the tumour location and degree of linguistic impairment. DuLIP is a valid test battery for pre-, intraoperative and postoperative language testing and facilitates intraoperative mapping of eloquent language regions that are variably located. PMID:25526520

  12. Neurons Differentiated from Transplanted Stem Cells Respond Functionally to Acoustic Stimuli in the Awake Monkey Brain.

    PubMed

    Wei, Jing-Kuan; Wang, Wen-Chao; Zhai, Rong-Wei; Zhang, Yu-Hua; Yang, Shang-Chuan; Rizak, Joshua; Li, Ling; Xu, Li-Qi; Liu, Li; Pan, Ming-Ke; Hu, Ying-Zhou; Ghanemi, Abdelaziz; Wu, Jing; Yang, Li-Chuan; Li, Hao; Lv, Long-Bao; Li, Jia-Li; Yao, Yong-Gang; Xu, Lin; Feng, Xiao-Li; Yin, Yong; Qin, Dong-Dong; Hu, Xin-Tian; Wang, Zheng-Bo

    2016-07-26

    Here, we examine whether neurons differentiated from transplanted stem cells can integrate into the host neural network and function in awake animals, a goal of transplanted stem cell therapy in the brain. We have developed a technique in which a small "hole" is created in the inferior colliculus (IC) of rhesus monkeys, then stem cells are transplanted in situ to allow for investigation of their integration into the auditory neural network. We found that some transplanted cells differentiated into mature neurons and formed synaptic input/output connections with the host neurons. In addition, c-Fos expression increased significantly in the cells after acoustic stimulation, and multichannel recordings indicated IC specific tuning activities in response to auditory stimulation. These results suggest that the transplanted cells have the potential to functionally integrate into the host neural network. PMID:27425612

  13. Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state.

    PubMed

    Bellay, Timothy; Klaus, Andreas; Seshadri, Saurav; Plenz, Dietmar

    2015-07-07

    Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output. Here, we study spontaneous firing in pyramidal neurons (PNs) from rat superficial cortical layers in vivo and in vitro using 2-photon imaging. As the animal transitions from the anesthetized to awake state, spontaneous single neuron firing increases in irregularity and assembles into scale-invariant avalanches at the group level. In vitro spike avalanches emerged naturally yet required balanced excitation and inhibition. This demonstrates that neuronal avalanches are linked to the global physiological state of wakefulness and that cortical resting activity organizes as avalanches from firing of local PN groups to global population activity.

  14. Epidural anaesthesia through caudal catheters for inguinal herniotomies in awake ex-premature babies.

    PubMed

    Peutrell, J M; Hughes, D G

    1993-02-01

    Ex-premature babies are at risk of apnoea after surgery. Regional anaesthesia has been used as an alternative to general anaesthesia for some surgical procedures in the belief that it may be safer. However, single dose caudal epidural and subarachnoid anaesthetics have a duration of action which may be insufficient for some operations. The level and duration of anaesthesia can be extended if local anaesthetic is given through an epidural catheter. In addition, the dose needed to provide adequate anaesthesia may be lower because the local anaesthetic is given at an appropriate segmental level. We report our experience of caudal epidural anaesthesia in nine, awake ex-premature babies who were having inguinal herniotomies. The anaesthesia was excellent in six babies. Two babies cried briefly with peritoneal or spermatic cord traction. One other baby needed supplementation with nitrous oxide in oxygen in order to complete the surgery. The majority of babies slept throughout surgery. There were no reported postoperative complications. PMID:8460759

  15. Long-term optical imaging of intrinsic signals in anesthetized and awake monkeys

    NASA Astrophysics Data System (ADS)

    Roe, Anna W.

    2007-04-01

    Some exciting new efforts to use intrinsic signal optical imaging methods for long-term studies in anesthetized and awake monkeys are reviewed. The development of such methodologies opens the door for studying behavioral states such as attention, motivation, memory, emotion, and other higher-order cognitive functions. Long-term imaging is also ideal for studying changes in the brain that accompany development, plasticity, and learning. Although intrinsic imaging lacks the temporal resolution offered by dyes, it is a high spatial resolution imaging method that does not require application of any external agents to the brain. The bulk of procedures described here have been developed in the monkey but can be applied to the study of surface structures in any in vivo preparation.

  16. Pleural liquid clearance rate measured in awake sheep by the volume of dilution method

    SciTech Connect

    Broaddus, V.C.; Wiener-Kronish, J.P.; Berthiaume, Y.; Staub, N.C.

    1986-03-01

    The authors reported 24h clearance of mock pleural effusions measured terminally in sheep. To measure effusion volume at different times in the same sheep, they injected /sup 111/In-transferrin and measured its dilution. In 5 sheep with effusions of known sizes, the method was accurate to +/-10%. In 5 awake sheep, the authors injected 10 ml/kg of a 1% protein solution via a non-penetrating rib capsule. At 6h, the authors measured the volume by the dilution method and at 24h by direct recovery. The clearance rate in each animal was constant at 2.9-6.0%/h (average 4.8 +/- 1.3%/h). This new method gives a reliable two point clearance rate and requires fewer animals.

  17. Replicability and Heterogeneity of Awake Unrestrained Canine fMRI Responses

    PubMed Central

    Berns, Gregory S.; Brooks, Andrew; Spivak, Mark

    2013-01-01

    Previously, we demonstrated the possibility of fMRI in two awake and unrestrained dogs. Here, we determined the replicability and heterogeneity of these results in an additional 11 dogs for a total of 13 subjects. Based on an anatomically placed region-of-interest, we compared the caudate response to a hand signal indicating the imminent availability of a food reward to a hand signal indicating no reward. 8 of 13 dogs had a positive differential caudate response to the signal indicating reward. The mean differential caudate response was 0.09%, which was similar to a comparable human study. These results show that canine fMRI is reliable and can be done with minimal stress to the dogs. PMID:24324719

  18. Millisecond Coupling of Local Field Potentials to Synaptic Currents in the Awake Visual Cortex.

    PubMed

    Haider, Bilal; Schulz, David P A; Häusser, Michael; Carandini, Matteo

    2016-04-01

    The cortical local field potential (LFP) is a common measure of population activity, but its relationship to synaptic activity in individual neurons is not fully established. This relationship has been typically studied during anesthesia and is obscured by shared slow fluctuations. Here, we used patch-clamp recordings in visual cortex of anesthetized and awake mice to measure intracellular activity; we then applied a simple method to reveal its coupling to the simultaneously recorded LFP. LFP predicted membrane potential as accurately as synaptic currents, indicating a major role for synaptic currents in the relationship between cortical LFP and intracellular activity. During anesthesia, cortical LFP predicted excitation far better than inhibition; during wakefulness, it predicted them equally well, and visual stimulation further enhanced predictions of inhibition. These findings reveal a central role for synaptic currents, and especially inhibition, in the relationship between the subthreshold activity of individual neurons and the cortical LFP during wakefulness. PMID:27021173

  19. Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state.

    PubMed

    Bellay, Timothy; Klaus, Andreas; Seshadri, Saurav; Plenz, Dietmar

    2015-01-01

    Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output. Here, we study spontaneous firing in pyramidal neurons (PNs) from rat superficial cortical layers in vivo and in vitro using 2-photon imaging. As the animal transitions from the anesthetized to awake state, spontaneous single neuron firing increases in irregularity and assembles into scale-invariant avalanches at the group level. In vitro spike avalanches emerged naturally yet required balanced excitation and inhibition. This demonstrates that neuronal avalanches are linked to the global physiological state of wakefulness and that cortical resting activity organizes as avalanches from firing of local PN groups to global population activity. PMID:26151674

  20. Neural oscillation, network, eloquent cortex and epileptogenic zone revealed by magnetoencephalography and awake craniotomy

    PubMed Central

    Idris, Zamzuri; Kandasamy, Regunath; Reza, Faruque; Abdullah, Jafri M.

    2014-01-01

    Background: Magnetoencephalography (MEG) is a method of functional neuroimaging. The concomitant use of MEG and electrocorticography has been found to be useful in elucidating neural oscillation and network, and to localize epileptogenic zone and functional cortex. We describe our early experience using MEG in neurosurgical patients, emphasizing on its impact on patient management as well as the enrichment of our knowledge in neurosciences. Materials and Methods: A total of 10 subjects were included; five patients had intraaxial tumors, one with an extraaxial tumor and brain compression, two with arteriovenous malformations, one with cerebral peduncle hemorrhage and one with sensorimotor cortical dysplasia. All patients underwent evoked and spontaneous MEG recordings. MEG data was processed at band-pass filtering frequency of between 0.1 and 300 Hz with a sampling rate of 1 kHz. MEG source localization was performed using either overdetermined equivalent current dipoles or underdetermined inversed solution. Neuromag collection of events software was used to study brain network and epileptogenic zone. The studied data were analyzed for neural oscillation in three patients; brain network and clinical manifestation in five patients; and for the location of epileptogenic zone and eloquent cortex in two patients. Results: We elucidated neural oscillation in three patients. One demonstrated oscillatory phenomenon on stimulation of the motor-cortex during awake surgery, and two had improvement in neural oscillatory parameters after surgery. Brain networks corresponding to clinico-anatomical relationships were depicted in five patients, and two networks were illustrated here. Finally, we demonstrated epilepsy cases in which MEG data was found to be useful in localizing the epileptogenic zones and functional cortices. Conclusion: The application of MEG while enhancing our knowledge in neurosciences also has a useful role in epilepsy and awake surgery. PMID:25685205

  1. Long-term facilitation of ventilation following repeated hypoxic episodes in awake goats.

    PubMed Central

    Turner, D L; Mitchell, G S

    1997-01-01

    1. This study tested two hypotheses: (1) that episodic hypoxia elicits long-term facilitation (LTF) in respiratory neurons that is manifest as an increase in ventilation in awake goats; and (2) that LTF causes complex changes in respiratory pattern which are responsible for the increase in ventilation. 2. Each goat participated in two protocols. In the first, inspired gas mixtures were alternated between isocapnic normoxia and hypoxia (arterial partial pressure of oxygen, Pa,O2 = 47 mmHg) for ten cycles. Each hypoxic episode lasted 3 min and normoxic intervals were 5 min. Ventilatory variables were measured during the last minute of each episode and periodically for up to 1 h following the last hypoxic episode. The second, sham protocol was undertaken at least 2 weeks later and was identical to the first, except that isocapnic hypoxia was replaced with normoxia. 3. Inspired ventilation (VI) increased during the first isocapnic hypoxic episode and reached progressively higher levels in subsequent hypoxic episodes. VI also increased progressively among normoxic intervals, such that by the tenth normoxic interval, it had increased 68% relative to the comparable sham value (P < 0.05). Respiratory frequency (FR), tidal volume and mean inspiratory flow all contributed to the augmented VI during both isocapnic normoxia and hypoxia. The increase in VI lasted up to 40 min after the final hypoxic episode, with an increased FR making the greatest contribution. The persistent increase in VI strongly suggests that episodic hypoxia elicits LTF in respiratory neurons in the awake goat. Complex changes in respiratory pattern underpin the ventilatory manifestation of LTF. PMID:9080380

  2. Activity patterns of the diaphragm during voluntary movements in awake cats.

    PubMed

    Uga, Minako; Niwa, Masatoshi; Ochiai, Naoyuki; Sasaki, Sei-Ichi

    2010-05-01

    The diaphragm is an important inspiratory muscle, and is also known to participate in the postural function. However, the activity of the diaphragm during voluntary movements has not been fully investigated in awake animals. In order to investigate the diaphragmatic activity during voluntary movements such as extending or rotating their body, we analyzed the electromyogram (EMG) of the diaphragm and trunk muscles in the cat using a technique for simultaneous recordings of EMG signals and video images. Periodic respiratory discharges occurred in the left and right costal diaphragm when the cat kept still. However, once the cat moved, their periodicity and/or synchrony were sometimes buried by non-respiratory activity. Such non-periodic diaphragmatic activities during voluntary movements are considered as the combination of respiratory activity and non-respiratory activity. Most of the diaphragmatic activities started shortly after the initiation of standing-up movements and occurred after the onset of trunk muscle activities. Those activities were more active compared to the normal respiratory activity. During rotation movements, left and right diaphragmatic activities showed asymmetrical discharge patterns and higher discharges than those during the resting situation. This asymmetrical activity may be caused by taking different lengths of each side of the diaphragm and trunk muscles. During reaching movements, the diaphragmatic activity occurred prior to or with the onset of trunk muscle activities. It is likely that diaphragmatic activities during reaching movements and standing-up movements may have been controlled by some different control mechanisms of the central nervous system. This study will suggest that the diaphragmatic activity is regulated not only by the respiratory center but also by inputs from the center for voluntary movements and/or sensory reflex pathways under the awake condition.

  3. Continuous thoracic epidural anesthesia induces segmental sympathetic block in the awake rat.

    PubMed

    Freise, Hendrik; Anthonsen, Sören; Fischer, Lars G; Van Aken, Hugo K; Sielenkämper, Andreas W

    2005-01-01

    Thoracic epidural anesthesia (TEA) is used increasingly in critical care, especially for cardiac and intestinal sympathetic block. In this study we evaluated cardiorespiratory function and sympathetic activity in a new model of continuous TEA in awake rats. Thirteen rats received epidural saline control (CON) or bupivacaine 0.5% epidural infusion (EPI) at 15 microl/h for 2 h on day 1 and day 3. Mean arterial blood pressure, heart rate, respiration rate, arterial PCO2, and motor score were recorded at baseline and after 30, 60, 90, and 120 min. Skin temperature was measured at front paws, high-thoracic, mid-thoracic, and low-thoracic, hind paws, and the proximal and distal tail. Changes in sympathetic activity were assessed by skin temperature changes from baseline (DeltaT). In the EPI group, hemodynamics and respiration remained unchanged and only mild motor deficits occurred. DeltaT in thoracic segments was higher in the EPI than in the CON group (P <0.001 at all times at high-thoracic, mid-thoracic, and low-thoracic segments). Skin temperature decreased in the distal tail in the EPI group, e.g., after 90 min DeltaT=-0.86 +/- 0.25 degrees C (EPI) versus 0.4 +/- 0.12 degrees C (CON) (P <0.05 at 60, 90, and 120 min). DeltaT on day 3 was comparable to day 1. TEA induced stable segmental sympathetic block without cardiorespiratory and motor side effects in awake rats. This new technique may be applied in prolonged models of critical illness. PMID:15616087

  4. A watertight acrylic-free titanium recording chamber for electrophysiology in behaving monkeys

    PubMed Central

    Economides, John R.; Jocson, Cristina M.; Parker, John M.; Horton, Jonathan C.

    2011-01-01

    Neurophysiological recording in alert monkeys requires the creation of a permanent aperture in the skull for repeated insertion of microelectrodes. Most laboratories use polymethyl methacrylate to attach a recording chamber over the skull opening. Here, we describe a titanium chamber that fastens to the skull with screws, using no polymethyl methacrylate. The gap between the base of the chamber and the skull is filled with hydroxyapatite, forming a watertight gasket. As the chamber base osseointegates with the skull, the hydroxyapatite is replaced with bone. Rather than having a finite lifetime, the recording chamber becomes more firmly anchored the longer it is in place. It has a small footprint, low profile, and needs little maintenance to control infection. Toilette consists of occasional application of betadine to clean the scalp margin, followed by application of neomycin, polymyxin, and bacitracin ointment. Antibiotic is also placed inside the chamber to suppress bacterial proliferation. Thickening of the dura within the chamber can be prevented by regular application of mitocycin C and/or bevacizumab, an antibody against vascular endothelial growth factor. By conducting an e-mail survey, this protocol for chamber maintenance was compared with procedures used in 37 other vision research laboratories. Refinement of appliances and techniques used for recordings in awake monkeys promises to increase the pace of scientific discovery and to benefit animal welfare. PMID:21676928

  5. Characterization of motor units in behaving adult mice shows a wide primary range.

    PubMed

    Ritter, Laura K; Tresch, Matthew C; Heckman, C J; Manuel, Marin; Tysseling, Vicki M

    2014-08-01

    The mouse is essential for genetic studies of motor function in both normal and pathological states. Thus it is important to consider whether the structure of motor output from the mouse is in fact analogous to that recorded in other animals. There is a striking difference in the basic electrical properties of mouse motoneurons compared with those in rats, cats, and humans. The firing evoked by injected currents produces a unique frequency-current (F-I) function that emphasizes recruitment of motor units at their maximum force. These F-I functions, however, were measured in anesthetized preparations that lacked two key components of normal synaptic input: high levels of synaptic noise and neuromodulatory inputs. Recent studies suggest that the alterations in the F-I function due to these two components are essential for recreating firing behavior of motor units in human subjects. In this study we provide the first data on firing patterns of motor units in the awake mouse, focusing on steady output in quiet stance. The resulting firing patterns did not match the predictions from the mouse F-I behaviors but instead revealed rate modulation across a remarkably wide range (10-60 Hz). The low end of the firing range may be due to changes in the F-I relation induced by synaptic noise and neuromodulatory inputs. The high end of the range may indicate that, unlike other species, quiet standing in the mouse involves recruitment of relatively fast-twitch motor units. PMID:24805075

  6. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage. PMID:24110073

  7. Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas.

    PubMed

    Kolvin, Itamar; Livne, Eli; Meerson, Baruch

    2010-08-01

    We show that, in dimension higher than one, heat diffusion and viscosity cannot arrest thermal collapse in a freely evolving dilute granular gas, even in the absence of gravity. Thermal collapse involves a finite-time blowup of the gas density. It was predicted earlier in ideal, Euler hydrodynamics of dilute granular gases in the absence of gravity, and in nonideal, Navier-Stokes granular hydrodynamics in the presence of gravity. We determine, analytically and numerically, the dynamic scaling laws that characterize the gas flow close to collapse. We also investigate bifurcations of a freely evolving dilute granular gas in circular and wedge-shaped containers. Our results imply that, in general, thermal collapse can only be arrested when the gas density becomes comparable with the close-packing density of grains. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows.

  8. Between soap bubbles and vesicles: The dynamics of freely floating smectic bubbles

    NASA Astrophysics Data System (ADS)

    Stannarius, Ralf; May, Kathrin; Harth, Kirsten; Trittel, Torsten

    2013-03-01

    The dynamics of droplets and bubbles, particularly on microscopic scales, are of considerable importance in biological, environmental, and technical contexts. We introduce freely floating bubbles of smectic liquid crystals and report their unique dynamic properties. Smectic bubbles can be used as simple models for dynamic studies of fluid membranes. In equilibrium, they form minimal surfaces like soap films. However, shape transformations of closed smectic membranes that change the surface area involve the formation and motion of molecular layer dislocations. These processes are slow compared to the capillary wave dynamics, therefore the effective surface tension is zero like in vesicles. Freely floating smectic bubbles are prepared from collapsing catenoid films and their dynamics is studied with optical high-speed imaging. Experiments are performed under normal gravity and in microgravity during parabolic flights. Supported by DLR within grant OASIS-Co.

  9. Multiple leading edge vortices of unexpected strength in freely flying hawkmoth

    PubMed Central

    Johansson, L. Christoffer; Engel, Sophia; Kelber, Almut; Heerenbrink, Marco Klein; Hedenström, Anders

    2013-01-01

    The Leading Edge Vortex (LEV) is a universal mechanism enhancing lift in flying organisms. LEVs, generally illustrated as a single vortex attached to the wing throughout the downstroke, have not been studied quantitatively in freely flying insects. Previous findings are either qualitative or from flappers and tethered insects. We measure the flow above the wing of freely flying hawkmoths and find multiple simultaneous LEVs of varying strength and structure along the wingspan. At the inner wing there is a single, attached LEV, while at mid wing there are multiple LEVs, and towards the wingtip flow separates. At mid wing the LEV circulation is ~40% higher than in the wake, implying that the circulation unrelated to the LEV may reduce lift. The strong and complex LEV suggests relatively high flight power in hawmoths. The variable LEV structure may result in variable force production, influencing flight control in the animals. PMID:24253180

  10. Dual-modal (OIS/LSCI) imager of cerebral cortex in freely moving animals

    NASA Astrophysics Data System (ADS)

    Lu, Hongyang; Miao, Peng; Liu, Qi; Li, Yao; Tong, Shanbao

    2012-03-01

    Optical intrinsic signals (OIS) and laser speckle contrast imaging (LSCI) have been used for years in the study of the cerebral blood flow (CBF) and hemodynamic responses to the neural activity under functional stimulation. So far, most in vivo rodent experiments are based on the anesthesia model when the animals are in unconscious and restrained conditions. The influences of anesthesia on the neural activity have been documented in literature. In this study, we designed a miniature head-mounted dual-modal imager in freely moving animals that could monitor in real time the coupling of local oxygen consumption and blood perfusion of CBF by integrating different imaging modalities of OIS and LSCI. The system facilitates the study the cortical hemodynamics and neural-hemodynamic coupling in real time in freely moving animals.

  11. Dual-modal (OIS/LSCI) imager of cerebral cortex in freely moving animals

    NASA Astrophysics Data System (ADS)

    Lu, Hongyang; Miao, Peng; Liu, Qi; Li, Yao; Tong, Shanbao

    2011-11-01

    Optical intrinsic signals (OIS) and laser speckle contrast imaging (LSCI) have been used for years in the study of the cerebral blood flow (CBF) and hemodynamic responses to the neural activity under functional stimulation. So far, most in vivo rodent experiments are based on the anesthesia model when the animals are in unconscious and restrained conditions. The influences of anesthesia on the neural activity have been documented in literature. In this study, we designed a miniature head-mounted dual-modal imager in freely moving animals that could monitor in real time the coupling of local oxygen consumption and blood perfusion of CBF by integrating different imaging modalities of OIS and LSCI. The system facilitates the study the cortical hemodynamics and neural-hemodynamic coupling in real time in freely moving animals.

  12. Development of implantable optoelectronic module for optical brain tissue stimulation in freely moving mice

    NASA Astrophysics Data System (ADS)

    Rusakov, Konstantin; Czajkowski, Rafał; Kaźmierczak, Andrzej

    2015-09-01

    The research aims to design and manufacture of wireless optogenetics devices for freely moving animals in cages IntelliCage system. The purpose of the device is to stimulate specific brain regions using light. The constructed device consists of a light source and optical fibre structure responsible for delivering light into the corresponding region of the brain of the animal. The size of the animal (mouse) and the fact that it is freely moving imposes substantial limitations with respect to the size and weight of the optoelectronic device. The present paper describes research on optical fibre structure fabrication, assembling it to the small size (less than 500 × 500 μm2 top surface) LED chip and experimental validation of the optoelectronic stimulator.

  13. Navier-Stokes hydrodynamics of thermal collapse in a freely cooling granular gas.

    PubMed

    Kolvin, Itamar; Livne, Eli; Meerson, Baruch

    2010-08-01

    We show that, in dimension higher than one, heat diffusion and viscosity cannot arrest thermal collapse in a freely evolving dilute granular gas, even in the absence of gravity. Thermal collapse involves a finite-time blowup of the gas density. It was predicted earlier in ideal, Euler hydrodynamics of dilute granular gases in the absence of gravity, and in nonideal, Navier-Stokes granular hydrodynamics in the presence of gravity. We determine, analytically and numerically, the dynamic scaling laws that characterize the gas flow close to collapse. We also investigate bifurcations of a freely evolving dilute granular gas in circular and wedge-shaped containers. Our results imply that, in general, thermal collapse can only be arrested when the gas density becomes comparable with the close-packing density of grains. This provides a natural explanation to the formation of densely packed clusters of particles in a variety of initially dilute granular flows. PMID:20866801

  14. Experimental measurement of the flow field around a freely swimming microorganism

    NASA Astrophysics Data System (ADS)

    Polin, Marco; Drescher, Knut; Goldstein, Raymond; Michel, Nicolas; Tuval, Idan

    2010-03-01

    Despite their small size, the fluid flows produced by billions of microscopic swimmers in nature can have dramatic macroscopic effects (e.g. biogenic mixing in the ocean). Understanding the flow structure of a single swimming microorganism is essential to explain and model these macroscopic phenomena. Here we report the first detailed measurement of the flow field around an isolated, freely swimming microorganism, the spherical alga Volvox, and discuss the implications of this measurement for other species.

  15. Hybrid Metameterials Enable Fast Electrical Modulation Of Freely Propagating Terahertz Waves

    SciTech Connect

    Chen, Hou-tong; O' Hara, John F; Taylor, Antoinette J

    2008-01-01

    We demonstrate fast electrical modulation of freely propagating THz waves at room temperature using hybrid metamaterial devices. the devices are planar metamaterials fabricated on doped semiconducor epitaxial layers, which form hybrid metamaterial - Schottky diode structures. With an applied ac voltage bias, we show modulation of THz radiation at inferred frequencies over 2 MHz. The modulation speed is limited by the device depletion capacitance which may be reduced for even faster operation.

  16. A novel synthetic route to freely adjust the crystal structures of Ni-P compounds

    NASA Astrophysics Data System (ADS)

    Xu, Hanghui; Lu, Shaoxiang; Ren, Lili

    2016-10-01

    Crystal-structure-controllable Ni-P compounds were synthesized using nickel chloride, nontoxic red phosphorus and polyethylene glycol. The hexagonal Ni2P and tetragonal Ni12P5 could be freely transformed via adjusting the amount of polyethylene glycol, and the mechanism of phase transformation was discussed. The catalytic performances of Ni-P compounds were promoted markedly with moderate quantity of PEG. However, excessive PEG will cover the active sites of catalysts and decrease the catalytic activity.

  17. Labyrinthine instability in freely suspended films of a polarization-modulated smectic phase

    NASA Astrophysics Data System (ADS)

    Eremin, Alexey; Kornek, Ulrike; Stannarius, Ralf; Weissflog, Wolfgang; Nádasi, Hajnalka; Araoka, Fumito; Takezoe, Hideo

    2013-12-01

    We report on fingering and labyrinthine instabilities of the layer dislocation lines in freely suspended polar liquid-crystalline films. These polar fingerlike and labyrinth structures reversibly form upon a transition into a modulated phase. External electric fields of several kV/m applied in the film plane can reversibly influence the formation of the finger textures. We show that the labyrinthine pattern is intrinsically related to regular splay deformations of the polarization.

  18. Using dislocations to probe surface reconstruction in thick freely suspended liquid crystalline films

    NASA Astrophysics Data System (ADS)

    Collett, J. A.; Martinez Zambrano, Daniel

    2015-10-01

    Surface interactions can cause freely suspended thin liquid crystalline films to form phases different from the bulk material, but it is not known what happens at the surface of thick films. Edge dislocations can be used as a marker for the boundary between the bulk center and the reconstructed surface. We use noncontact mode atomic force microscopy to determine the depth of edge dislocations below the surface of freely suspended thick films of 4-n -heptyloxybenzylidene-4-n -heptylaniline (7O.7) in the crystalline B phase. Here, 3.0 ±0.1 nm high steps are found with a width that varies with temperature between 56 and 59 ∘C. Using a strain model for the profile of liquid crystalline layers above an edge dislocation to estimate the depth of the dislocation, we find that the number of reconstructed surface layers increases from 4 to 50 layers as the temperature decreases from 59 to 56 ∘C . This trend tracks the behavior of the phase boundary in the thickness dependent phase diagram of freely suspended films of 7O.7, suggesting that the surface may be reconstructed into a smectic F region.

  19. Nanoscopic Terraces, Mesas, and Ridges in Freely Standing Thin Films Sculpted by Supramolecular Oscillatory Surface Forces.

    PubMed

    Zhang, Yiran; Yilixiati, Subinuer; Pearsall, Collin; Sharma, Vivek

    2016-04-26

    Freely standing thin liquid films containing supramolecular structures including micelles, nanoparticles, polyelectrolyte-surfactant complexes, and smectic liquid crystals undergo drainage via stratification. The layer-by-layer removal of these supramolecular structures manifests as stepwise thinning over time and a coexistence of domains and nanostructures of discretely different thickness. The layering of supramolecular structures in confined thin films contributes additional non-DLVO, supramolecular oscillatory surface forces to disjoining pressure, thus influencing both drainage kinetics and stability of thin films. Understanding and characterizing the spontaneous creation and evolution of nanoscopic topography of stratifying, freely standing thin liquid films have been long-standing challenges due to the absence of experimental techniques with the requisite spatial (thickness <10 nm) and temporal resolution (<1 ms). Using Interferometry Digital Imaging Optical Microscopy (IDIOM) protocols developed herein, we visualize and characterize size, shape, and evolution kinetics of nanoscopic mesas, terraces, and ridges. The exquisite thickness maps created using IDIOM protocols provide much needed and unprecedented insights into the role of supramolecular oscillatory surface forces in driving growth of such nanostructures as well as in controlling properties and stability of freely standing thin films and, more generally, of colloidal dispersions like foams.

  20. Gamma (40-100 Hz) oscillation in the hippocampus of the behaving rat.

    PubMed

    Bragin, A; Jandó, G; Nádasdy, Z; Hetke, J; Wise, K; Buzsáki, G

    1995-01-01

    The cellular generation and spatial distribution of gamma frequency (40-100 Hz) activity was examined in the hippocampus of the awake rat. Field potentials and unit activity were recorded by multiple site silicon probes (5- and 16-site shanks) and wire electrode arrays. Gamma waves were highly coherent along the long axis of the dentate hilus, but average coherence decreased rapidly in the CA3 and CA1 directions. Analysis of short epochs revealed large fluctuations in coherence values between the dentate and CA1 gamma waves. Current source density analysis revealed large sinks and sources in the dentate gyrus with spatial distribution similar to the dipoles evoked by stimulation of the perforant path. The frequency changes of gamma and theta waves positively correlated (40-100 Hz and 5-10 Hz, respectively). Putative interneurons in the dentate gyrus discharged at gamma frequency and were phase-locked to the ascending part of the gamma waves recorded from the hilus. Following bilateral lesion of the entorhinal cortex the power and frequency of hilar gamma activity significantly decreased or disappeared. Instead, a large amplitude but slower gamma pattern (25-50 Hz) emerged in the CA3-CA1 network. We suggest that gamma oscillation emerges from an interaction between intrinsic oscillatory properties of interneurons and the network properties of the dentate gyrus. We also hypothesize that under physiological conditions the hilar gamma oscillation may be entrained by the entorhinal rhythm and that gamma oscillation in the CA3-CA1 circuitry is suppressed by either the hilar region or the entorhinal cortex.

  1. Use of extracorporeal membrane oxygenation in an awake patient after a major trauma with an incidental finding of tuberculosis.

    PubMed

    Haneke, F; Schildhauer, T A; Strauch, J; Swol, J

    2016-05-01

    We report the use of extracorporeal membrane oxygenation (ECMO) in a trauma patient with an incidental finding of open tuberculosis (TB). Sedation was reduced during extracorporeal support and awake veno-venous ECMO was successfully performed. Subsequently, accidental cannula removal caused major blood loss which required the administration of cardiopulmonary resuscitation (CPR). Our case report demonstrates that the incidental finding of open TB is an important hint for differential diagnosis and that it should still be considered in high-income countries. In addition, awake ECMO appears to be a feasible therapeutic option in non-transplant patients, although the described case demonstrates that patient compliance and nursing care are important for therapeutic success to avoid complications, for example, inadvertent decannulation. PMID:26498750

  2. Large-scale Recording of Neurons by Movable Silicon Probes in Behaving Rodents

    PubMed Central

    Vandecasteele, Marie; M., S.; Royer, Sébastien; Belluscio, Mariano; Berényi, Antal; Diba, Kamran; Fujisawa, Shigeyoshi; Grosmark, Andres; Mao, Dun; Mizuseki, Kenji; Patel, Jagdish; Stark, Eran; Sullivan, David; Watson, Brendon; Buzsáki, György

    2012-01-01

    A major challenge in neuroscience is linking behavior to the collective activity of neural assemblies. Understanding of input-output relationships of neurons and circuits requires methods with the spatial selectivity and temporal resolution appropriate for mechanistic analysis of neural ensembles in the behaving animal, i.e. recording of representatively large samples of isolated single neurons. Ensemble monitoring of neuronal activity has progressed remarkably in the past decade in both small and large-brained animals, including human subjects1-11. Multiple-site recording with silicon-based devices are particularly effective because of their scalability, small volume and geometric design. Here, we describe methods for recording multiple single neurons and local field potential in behaving rodents, using commercially available micro-machined silicon probes with custom-made accessory components. There are two basic options for interfacing silicon probes to preamplifiers: printed circuit boards and flexible cables. Probe supplying companies (http://www.neuronexustech.com/; http://www.sbmicrosystems.com/; http://www.acreo.se/) usually provide the bonding service and deliver probes bonded to printed circuit boards or flexible cables. Here, we describe the implantation of a 4-shank, 32-site probe attached to flexible polyimide cable, and mounted on a movable microdrive. Each step of the probe preparation, microdrive construction and surgery is illustrated so that the end user can easily replicate the process. PMID:22415550

  3. An Improved Quantum-Behaved Particle Swarm Optimization Algorithm with Elitist Breeding for Unconstrained Optimization

    PubMed Central

    Yang, Zhen-Lun; Wu, Angus; Min, Hua-Qing

    2015-01-01

    An improved quantum-behaved particle swarm optimization with elitist breeding (EB-QPSO) for unconstrained optimization is presented and empirically studied in this paper. In EB-QPSO, the novel elitist breeding strategy acts on the elitists of the swarm to escape from the likely local optima and guide the swarm to perform more efficient search. During the iterative optimization process of EB-QPSO, when criteria met, the personal best of each particle and the global best of the swarm are used to generate new diverse individuals through the transposon operators. The new generated individuals with better fitness are selected to be the new personal best particles and global best particle to guide the swarm for further solution exploration. A comprehensive simulation study is conducted on a set of twelve benchmark functions. Compared with five state-of-the-art quantum-behaved particle swarm optimization algorithms, the proposed EB-QPSO performs more competitively in all of the benchmark functions in terms of better global search capability and faster convergence rate. PMID:26064085

  4. A Novel Quantum-Behaved Bat Algorithm with Mean Best Position Directed for Numerical Optimization.

    PubMed

    Zhu, Binglian; Zhu, Wenyong; Liu, Zijuan; Duan, Qingyan; Cao, Long

    2016-01-01

    This paper proposes a novel quantum-behaved bat algorithm with the direction of mean best position (QMBA). In QMBA, the position of each bat is mainly updated by the current optimal solution in the early stage of searching and in the late search it also depends on the mean best position which can enhance the convergence speed of the algorithm. During the process of searching, quantum behavior of bats is introduced which is beneficial to jump out of local optimal solution and make the quantum-behaved bats not easily fall into local optimal solution, and it has better ability to adapt complex environment. Meanwhile, QMBA makes good use of statistical information of best position which bats had experienced to generate better quality solutions. This approach not only inherits the characteristic of quick convergence, simplicity, and easy implementation of original bat algorithm, but also increases the diversity of population and improves the accuracy of solution. Twenty-four benchmark test functions are tested and compared with other variant bat algorithms for numerical optimization the simulation results show that this approach is simple and efficient and can achieve a more accurate solution. PMID:27293424

  5. A Novel Quantum-Behaved Bat Algorithm with Mean Best Position Directed for Numerical Optimization

    PubMed Central

    Zhu, Wenyong; Liu, Zijuan; Duan, Qingyan; Cao, Long

    2016-01-01

    This paper proposes a novel quantum-behaved bat algorithm with the direction of mean best position (QMBA). In QMBA, the position of each bat is mainly updated by the current optimal solution in the early stage of searching and in the late search it also depends on the mean best position which can enhance the convergence speed of the algorithm. During the process of searching, quantum behavior of bats is introduced which is beneficial to jump out of local optimal solution and make the quantum-behaved bats not easily fall into local optimal solution, and it has better ability to adapt complex environment. Meanwhile, QMBA makes good use of statistical information of best position which bats had experienced to generate better quality solutions. This approach not only inherits the characteristic of quick convergence, simplicity, and easy implementation of original bat algorithm, but also increases the diversity of population and improves the accuracy of solution. Twenty-four benchmark test functions are tested and compared with other variant bat algorithms for numerical optimization the simulation results show that this approach is simple and efficient and can achieve a more accurate solution. PMID:27293424

  6. Effects of Optogenetic Activation of Corticothalamic Terminals in the Motor Thalamus of Awake Monkeys

    PubMed Central

    Hu, Xing; Smith, Yoland; Wichmann, Thomas

    2016-01-01

    The role of the corticothalamic projection in the ventral motor thalamus remains poorly understood. Therefore, we studied the electrophysiological responses of neurons in the basal ganglia and cerebellar receiving-territories of the motor thalamus (BGMT and CbMT, respectively) using optogenetic activation of corticothalamic projections in awake rhesus macaques. After injections of viral vectors carrying the excitatory opsins ChR2 or C1V1 into the primary motor and premotor cortices of two monkeys, we used optrodes to light activate opsin-expressing neurons in cortex or their terminals in the thalamus while simultaneously recording the extracellular activity of neurons in the vicinity of the stimulation sites. As expected, light activation of opsins in the cerebral cortex evoked robust, short-latency increases in firing of cortical neurons. In contrast, light stimulation of corticothalamic terminals induced small-amplitude, long-latency increases and/or decreases of activity in thalamic neurons. In postmortem material, opsins were found to be expressed in cell bodies and dendrites of cortical neurons and along their corticothalamic projections. At the electron microscopic level, opsin labeling was confined to unmyelinated preterminal axons and small terminals that formed asymmetric synapses with dendrites of projection neurons or GABAergic interneurons in BGMT and CbMT and with neurons in the reticular thalamic nucleus. The morphological features of the transfected terminals, along with the long latency and complex physiological responses of thalamic neurons to their activation, suggest a modulatory role of corticothalamic afferents upon the primate ventral motor thalamus. SIGNIFICANCE STATEMENT This study provides the first analysis of the physiological effects of cortical inputs on the activity of neurons in the primate ventral motor thalamus using light activation of opsin-containing corticothalamic terminals in awake monkeys. We found that selective light

  7. Biofeedback for treatment of awake and sleep bruxism in adults: systematic review protocol

    PubMed Central

    2014-01-01

    Background Bruxism is a disorder of jaw-muscle activity characterised by repetitive clenching or grinding of the teeth which results in discomfort and damage to dentition. The two clinical manifestations of the condition (sleep and awake bruxism) are thought to have unrelated aetiologies but are palliated using similar techniques. The lack of a definitive treatment has prompted renewed interest in biofeedback, a behaviour change method that uses electronic detection to provide a stimulus whenever bruxism occurs. This systematic review aims to provide a comprehensive overview of the state of research into biofeedback for bruxism; to assess the efficacy and acceptability of biofeedback therapy in management of awake bruxism and, separately, sleep bruxism in adults; and to compare findings between the two variants. Methods A systematic review of published literature examining biofeedback as an intervention directed at controlling primary bruxism in adults. We will search electronic databases and the grey literature using a predefined search strategy to identify randomised and non-randomised studies, technical reports and patents. Searches will not be restricted by language or date and will be expanded through contact with authors and experts, and by following up reference lists and citations. Two authors, working independently, will conduct screening of search results, study selection, data extraction and quality assessment and a third will resolve any disagreements. The primary outcomes of acceptability and effectiveness will be assessed using only randomised studies, segregated by bruxism subtype. A meta-analysis of these data will be conducted only if pre-defined conditions for quality and heterogeneity are met, otherwise the data will be summarized in narrative form. Data from non-randomised studies will be used to augment a narrative synthesis of the state of technical developments and any safety-related issues. PROSPERO registration number: CRD42013006880

  8. Significance of time awake for predicting pilots' fatigue on short-haul flights: implications for flight duty time regulations.

    PubMed

    Vejvoda, Martin; Elmenhorst, Eva-Maria; Pennig, Sibylle; Plath, Gernot; Maass, Hartmut; Tritschler, Kristjof; Basner, Mathias; Aeschbach, Daniel

    2014-10-01

    European regulations restrict the duration of the maximum daily flight duty period for pilots as a function of the duty start time and the number of scheduled flights. However, late duty end times that may include long times awake are not specifically regulated. In this study, fatigue levels in pilots finishing their duty late at night (00:00-01:59 hour) were analysed and compared with pilots starting their duty early (05:00-06:59 hour). Fatigue levels of 40 commercial short-haul pilots were studied during a total of 188 flight duty periods, of which 87 started early and 22 finished late. Pilots used a small handheld computer to maintain a duty and sleep log, and to indicate fatigue levels immediately after each flight. Sleep logs were checked with actigraphy. Pilots on late-finishing flight duty periods were more fatigued at the end of their duty than pilots on early-starting flight duty periods, despite the fact that preceding sleep duration was longer by 1.1 h. Linear mixed-model regression identified time awake as a preeminent factor predicting fatigue. Workload had a minor effect. Pilots on late-finishing flight duty periods were awake longer by an average of 5.5 h (6.6 versus 1.1 h) before commencing their duty than pilots who started early in the morning. Late-finishing flights were associated with long times awake at a time when the circadian system stops promoting alertness, and an increased, previously underestimated fatigue risk. Based on these findings, flight duty limitations should consider not only duty start time, but also the time of the final landing. PMID:25040665

  9. Significance of time awake for predicting pilots' fatigue on short-haul flights: implications for flight duty time regulations.

    PubMed

    Vejvoda, Martin; Elmenhorst, Eva-Maria; Pennig, Sibylle; Plath, Gernot; Maass, Hartmut; Tritschler, Kristjof; Basner, Mathias; Aeschbach, Daniel

    2014-10-01

    European regulations restrict the duration of the maximum daily flight duty period for pilots as a function of the duty start time and the number of scheduled flights. However, late duty end times that may include long times awake are not specifically regulated. In this study, fatigue levels in pilots finishing their duty late at night (00:00-01:59 hour) were analysed and compared with pilots starting their duty early (05:00-06:59 hour). Fatigue levels of 40 commercial short-haul pilots were studied during a total of 188 flight duty periods, of which 87 started early and 22 finished late. Pilots used a small handheld computer to maintain a duty and sleep log, and to indicate fatigue levels immediately after each flight. Sleep logs were checked with actigraphy. Pilots on late-finishing flight duty periods were more fatigued at the end of their duty than pilots on early-starting flight duty periods, despite the fact that preceding sleep duration was longer by 1.1 h. Linear mixed-model regression identified time awake as a preeminent factor predicting fatigue. Workload had a minor effect. Pilots on late-finishing flight duty periods were awake longer by an average of 5.5 h (6.6 versus 1.1 h) before commencing their duty than pilots who started early in the morning. Late-finishing flights were associated with long times awake at a time when the circadian system stops promoting alertness, and an increased, previously underestimated fatigue risk. Based on these findings, flight duty limitations should consider not only duty start time, but also the time of the final landing.

  10. Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses.

    PubMed

    Low, Lucie A; Bauer, Lucy C; Pitcher, Mark H; Bushnell, M Catherine

    2016-08-01

    With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the "nociceptive" central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli.

  11. [Incidence and causes of early end in awake surgery for language mapping not directly related to eloquence].

    PubMed

    Villalba, Gloria; Pacreu, Susana; Fernández-Candil, Juan Luis; León, Alba; Serrano, Laura; Conesa, Gerardo

    2016-01-01

    The incidence and causes that may lead to an early end (unfinished cortical/subcortical mapping) of awake surgery for language mapping are little known. A study was conducted on 41 patients with brain glioma located in the language area that had awake surgery under conscious sedation. Surgery was ended early in 6 patients. The causes were: tonic-clonic seizure (1), lack of cooperation due to fatigue/sleep (4), whether or not word articulation was involved, a decreased level of consciousness for ammonia encephalopathy that required endotracheal intubation (1). There are causes that could be expected and in some cases avoided. Tumour size, preoperative aphasia, valproate treatment, and type of anaesthesia used are variables to consider to avoid failure in awake surgery for language mapping. With these results, the following measures are proposed: l) If the tumour is large, perform surgery in two times to avoid fatigue, 2) if patient has a preoperative aphasia, do not use sedation during surgery to ensure that sleepiness does not cause worse word articulation, 3) if the patient is on valproate treatment, it is necessary to rule out the pre-operative symptoms that are not due to ammonia encephalopathy.

  12. Noradrenergic inhibitory modulation in the caudal commissural NTS of the pressor response to chemoreflex activation in awake rats.

    PubMed

    Silva de Oliveira, Luciana C; Bonagamba, Leni G H; Machado, Benedito H

    2007-10-30

    In the present study we evaluated the possible modulatory role of noradrenaline on the neurotransmission of the peripheral chemoreflex afferents in the caudal commissural NTS of awake rats. To reach this goal we performed a dose-response curve to microinjection of increasing dose of noradrenaline into the caudal commissural NTS of awake rats and then the threshold dose, which produces minor changes in the baseline mean arterial pressure, was selected to be used in the chemoreflex experiment. The peripheral chemoreflex was activated with KCN before and after bilateral microinjections of noradrenaline (5 nMol/50 nL, threshold dose) into the NTS. The data show that microinjection of noradrenaline into the caudal NTS produced a significant reduction in the pressor response to the chemoreflex 30 s after the injection when compared to the control response (30+/-6 vs. 49+/-3 mm Hg) but no significant changes in the bradycardic response. The data indicate that noradrenaline in the caudal commissural NTS of awake rats may play an important inhibitory neuromodulatory role on the processing of the pressor/sympathoexcitatory component of the chemoreflex.

  13. Interhemispheric transfalcine approach and awake cortical mapping for resection of peri-atrial gliomas associated with the central lobule.

    PubMed

    Malekpour, Mahdi; Cohen-Gadol, Aaron A

    2015-02-01

    Medial posterior frontal and parietal gliomas extending to the peri-atrial region are difficult to reach surgically because of the working angle required to expose the lateral aspect of the tumor and the proximity of the tumor to the sensorimotor lobule; retraction of the sensorimotor cortex may lead to morbidity. The interhemispheric transfalcine approach is favorable and safe for resection of medial hemispheric tumors adjacent to the falx cerebri, but the literature on this approach is scarce. Awake cortical mapping using this operative route for tumors associated with the sensorimotor cortex has not been previously reported to our knowledge. We present the first case of a right medial posterior frontoparietal oligoastrocytoma that was resected through the interhemispheric transfalcine approach using awake cortical and subcortical mapping. Through a contralateral frontoparietal craniotomy, we excised a section of the falx and exposed the contralateral medial hemisphere. Cortical stimulation allowed localization of the supplementary motor cortex, and suprathreshold stimulation mapping excluded the primary motor cortex corresponding to the leg area. Gross total tumor resection was accomplished without any intraoperative or postoperative deficits. Awake cortical mapping using the contralateral transfalcine approach allows a "cross-court" operative route to map functional cortices and resect peri-atrial low-grade gliomas. This technique can minimize the otherwise necessary retraction on the ipsilateral hemisphere through an ipsilateral craniotomy.

  14. Restraint training for awake functional brain scanning of rodents can cause long-lasting changes in pain and stress responses

    PubMed Central

    Low, Lucie A.; Bauer, Lucy C.; Pitcher, Mark H.; Bushnell, M. Catherine

    2016-01-01

    Abstract With the increased interest in longitudinal brain imaging of awake rodents, it is important to understand both the short-term and long-term effects of restraint on sensory and emotional processing in the brain. To understand the effects of repeated restraint on pain behaviors and stress responses, we modeled a restraint protocol similar to those used to habituate rodents for magnetic resonance imaging scanning, and studied sensory sensitivity and stress hormone responses over 5 days. To uncover lasting effects of training, we also looked at responses to the formalin pain test 2 weeks later. We found that while restraint causes acute increases in the stress hormone corticosterone, it can also cause lasting reductions in nociceptive behavior in the formalin test, coupled with heightened corticosterone levels and increased activation of the “nociceptive” central nucleus of the amygdala, as seen by Fos protein expression. These results suggest that short-term repeated restraint, similar to that used to habituate rats for awake functional brain scanning, could potentially cause long-lasting changes in physiological and brain responses to pain stimuli that are stress-related, and therefore could potentially confound the functional activation patterns seen in awake rodents in response to pain stimuli. PMID:27058679

  15. [Incidence and causes of early end in awake surgery for language mapping not directly related to eloquence].

    PubMed

    Villalba, Gloria; Pacreu, Susana; Fernández-Candil, Juan Luis; León, Alba; Serrano, Laura; Conesa, Gerardo

    2016-01-01

    The incidence and causes that may lead to an early end (unfinished cortical/subcortical mapping) of awake surgery for language mapping are little known. A study was conducted on 41 patients with brain glioma located in the language area that had awake surgery under conscious sedation. Surgery was ended early in 6 patients. The causes were: tonic-clonic seizure (1), lack of cooperation due to fatigue/sleep (4), whether or not word articulation was involved, a decreased level of consciousness for ammonia encephalopathy that required endotracheal intubation (1). There are causes that could be expected and in some cases avoided. Tumour size, preoperative aphasia, valproate treatment, and type of anaesthesia used are variables to consider to avoid failure in awake surgery for language mapping. With these results, the following measures are proposed: l) If the tumour is large, perform surgery in two times to avoid fatigue, 2) if patient has a preoperative aphasia, do not use sedation during surgery to ensure that sleepiness does not cause worse word articulation, 3) if the patient is on valproate treatment, it is necessary to rule out the pre-operative symptoms that are not due to ammonia encephalopathy. PMID:26260205

  16. Sex-specific 24-h acetylcholine release profile in the medial prefrontal cortex: simultaneous measurement of spontaneous locomotor activity in behaving rats.

    PubMed

    Takase, K; Kimura, F; Yagami, T; Mitsushima, D

    2009-03-01

    The difference in visual object recognition by males and females suggests a sex-specific function in the medial prefrontal cortex (mPFC). In the present study, we performed an in vivo microdialysis study in three groups of rats (males, diestrous females, and proestrous females) to examine the potential sex difference in acetylcholine (ACh) release in the mPFC. The dialysate was automatically collected from the mPFC every 20 min for 24 h under freely moving conditions and the spontaneous locomotor activity was simultaneously monitored. Although ACh release in the mPFC during the dark phase was significantly greater than during the light phase in both sexes, the female rats consistently exhibited a significantly greater mean ACh release than the males. Spontaneous locomotor activity during the dark phase was also significantly greater than during the light phase in both sexes, but the females exhibited significantly greater spontaneous locomotor activity than the males. In addition, both sexes of rats were found to have significant positive correlations between ACh release and spontaneous locomotor activity, but females were found to have significantly greater correlation coefficients than males. Stereological methods were used to examine the number of choline acetyltransferase immunoreactive cells in the nucleus basalis magnocellularis and the horizontal diagonal band of Broca. The number of choline acetyltransferase immunoreactive cells in the nucleus basalis magnocellularis was also greater in females than males, suggesting a contribution to the higher ACh release in females. In contrast, no sex difference in the choline acetyltransferase immunoreactive cells was observed in the horizontal diagonal band of Broca. This is the first report to show a sex difference in the 24-h ACh release profile in the mPFC of behaving rats.

  17. Sex-specific 24-h acetylcholine release profile in the medial prefrontal cortex: simultaneous measurement of spontaneous locomotor activity in behaving rats.

    PubMed

    Takase, K; Kimura, F; Yagami, T; Mitsushima, D

    2009-03-01

    The difference in visual object recognition by males and females suggests a sex-specific function in the medial prefrontal cortex (mPFC). In the present study, we performed an in vivo microdialysis study in three groups of rats (males, diestrous females, and proestrous females) to examine the potential sex difference in acetylcholine (ACh) release in the mPFC. The dialysate was automatically collected from the mPFC every 20 min for 24 h under freely moving conditions and the spontaneous locomotor activity was simultaneously monitored. Although ACh release in the mPFC during the dark phase was significantly greater than during the light phase in both sexes, the female rats consistently exhibited a significantly greater mean ACh release than the males. Spontaneous locomotor activity during the dark phase was also significantly greater than during the light phase in both sexes, but the females exhibited significantly greater spontaneous locomotor activity than the males. In addition, both sexes of rats were found to have significant positive correlations between ACh release and spontaneous locomotor activity, but females were found to have significantly greater correlation coefficients than males. Stereological methods were used to examine the number of choline acetyltransferase immunoreactive cells in the nucleus basalis magnocellularis and the horizontal diagonal band of Broca. The number of choline acetyltransferase immunoreactive cells in the nucleus basalis magnocellularis was also greater in females than males, suggesting a contribution to the higher ACh release in females. In contrast, no sex difference in the choline acetyltransferase immunoreactive cells was observed in the horizontal diagonal band of Broca. This is the first report to show a sex difference in the 24-h ACh release profile in the mPFC of behaving rats. PMID:19162130

  18. PET measured evoked cerebral blood flow responses in an awake monkey

    SciTech Connect

    Perlmutter, J.S.; Lich, L.L.; Margenau, W.; Buchholz, S. )

    1991-03-01

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments.

  19. Neurobehavioral evidence for individual differences in canine cognitive control: an awake fMRI study.

    PubMed

    Cook, Peter F; Spivak, Mark; Berns, Gregory

    2016-09-01

    Based on behavioral evidence, the domestic dog has emerged as a promising comparative model of human self-control. However, while research on human inhibition has probed heterogeneity and neuropathology through an integration of neural and behavioral evidence, there are no parallel data exploring the brain mechanisms involved in canine inhibition. Here, using a combination of cognitive testing and awake neuroimaging in domestic dogs, we provide evidence precisely localizing frontal brain regions underpinning response inhibition in this species and demonstrate the dynamic relationship between these regions and behavioral measures of control. Thirteen dogs took part in an in-scanner go/no-go task and an out-of-scanner A-not-B test. A frontal brain region was identified showing elevated neural activity for all subjects during successful inhibition in the scanner, and dogs showing greater mean brain activation in this region produced fewer false alarms. Better performance in the go/no-go task was also correlated with fewer errors in the out-of-scanner A-not-B test, suggesting that dogs show consistent neurobehavioral individual differences in cognitive control, as is seen in humans. These findings help establish parity between human and canine mechanisms of self-control and pave the way for future comparative studies examining their function and dysfunction. PMID:27062134

  20. Sodium bicarbonate treatment prevents gastric emptying delay caused by acute exercise in awake rats.

    PubMed

    Silva, Moisés T B; Palheta-Junior, Raimundo C; Sousa, Daniel F; Fonseca-Magalhães, Patrícia A; Okoba, Willy; Campos, Caio P S; Oliveira, Ricardo B; Magalhães, Pedro J C; Santos, Armenio A

    2014-05-01

    Physical exercise, mainly after vigorous activity, may induce gastrointestinal dysmotility whose mechanisms are still unknown. We hypothesized that physical exercise and ensuing lactate-related acidemia alter gastrointestinal motor behavior. In the present study, we evaluated the effects of short-term exercise on gastric emptying rate in awake rats subjected to 15-min swimming sessions against a load equivalent to 5% of their body weight. After 0, 10, or 20 min of exercise testing, the rats were gavage fed with 1.5 ml of a liquid test meal (0.5 mg/ml of phenol red in 5% glucose solution) and euthanized 10 min postprandially to measure fractional gastric dye recovery. In addition to inducing acidemia and increasing blood lactate levels, acute exercise increased (P < 0.05) gastric retention. Such a phenomenon presented a positive correlation (P < 0.001) between blood lactate levels and fractional gastric dye recovery. Gastric retention and other acidbase-related changes were all prevented by NaHCO3 pretreatment. Additionally, exercise enhanced (P < 0.05) the marker's progression through the small intestine. In anesthetized rats, exercise increased (P < 0.05) gastric volume, measured by a balloon catheter in a barostat system. Compared with sedentary control rats, acute exercise also inhibited (P < 0.05) the contractility of gastric fundus strips in vitro. In conclusion, acute exercise delayed the gastric emptying of a liquid test meal by interfering with the acid-base balance. PMID:24557800

  1. Areas of the brain concerned with ventilatory load compensation in awake man

    PubMed Central

    Isaev, Gennadi; Murphy, Kevin; Guz, Abraham; Adams, Lewis

    2002-01-01

    There is broad agreement that the awake human ventilatory response to a moderate inspiratory load consists of a prolongation of inspiratory time (TI) with a maintenance of tidal volume (VT) and end-tidal PCO2 (PET,CO2), the response being severely blunted in sleep. There is no agreement on the mechanisms underlying this ventilatory response. Six naive healthy males (aged 39–44) were studied supine with their heads in a positron emission tomography (PET) scanner to allow relative regional cerebral blood flow (rCBF) to be measured with H215O given intravenously. A linearised resistive load (24 cmH2O (l s−1)−1) could be added to the inspiratory limb of a breathing valve inserted into a tightly fitting facemask; inspiratory flow was measured with a pneumotachograph. The load was applied, without alerting the subject, when the radioactivity first reached the head. Six scans were performed with and without the load, in each subject. Relative rCBF contrasts between the loaded and unloaded breathing states showed significant activations in inferior parietal cortex, prefrontal cortex, midbrain, basal ganglia and multiple cerebellar sites. No activations were found in the primary sensorimotor cortex. The findings suggest that there is a pattern of motor behavioural response to the uncomfortable sensation that inspiration is impeded. This results in a prolongation of TI, the maintenance of VT and a reduction in the degree of discomfort, presumably because of the reduction of mean negative pressure in the airways. PMID:11897862

  2. Automated working distance adjustment enables optical coherence tomography of the human larynx in awake patients

    PubMed Central

    Donner, Sabine; Bleeker, Sebastian; Ripken, Tammo; Ptok, Martin; Jungheim, Michael; Krueger, Alexander

    2015-01-01

    Abstract. Optical coherence tomography (OCT) provides structural information of laryngeal tissue which is comparable to histopathological analysis of biopsies taken under general anesthesia. In awake patients, movements impede clinically useful OCT acquisition. Therefore, an automatic compensation of movements was implemented into a swept source OCT-laryngoscope. Video and OCT beam path were combined in one tube of 10-mm diameter. Segmented OCT images served as distance sensor and a feedback control adjusted the working distance between 33 and 70 mm by synchronously translating the reference mirror and focusing lens. With this motion compensation, the tissue was properly visible in up to 88% of the acquisition time. During quiet respiration, OCT contrasted epithelium and lamina propria. Mean epithelial thickness was measured to be 109 and 135  μm in female and male, respectively. Furthermore, OCT of mucosal wave movements during phonation enabled estimation of the oscillation frequency and amplitude. Regarding clinical issues, the OCT-laryngoscope with automated working distance adjustment may support the estimation of the depth extent of epithelial lesions and contribute to establish an indication for a biopsy. Moreover, OCT of the vibrating vocal folds provides functional information, possibly giving further insight into mucosal behavior during the vibratory cycle. PMID:26158116

  3. Neural correlates of sensorimotor gating: a metabolic positron emission tomography study in awake rats.

    PubMed

    Rohleder, Cathrin; Jung, Fabienne; Mertgens, Hanna; Wiedermann, Dirk; Sué, Michael; Neumaier, Bernd; Graf, Rudolf; Leweke, F Markus; Endepols, Heike

    2014-01-01

    Impaired sensorimotor gating occurs in neuropsychiatric disorders such as schizophrenia and can be measured using the prepulse inhibition (PPI) paradigm of the acoustic startle response. This assay is frequently used to validate animal models of neuropsychiatric disorders and to explore the therapeutic potential of new drugs. The underlying neural network of PPI has been extensively studied with invasive methods and genetic modifications. However, its relevance for healthy untreated animals and the functional interplay between startle- and PPI-related areas during a PPI session is so far unknown. Therefore, we studied awake rats in a PPI paradigm, startle control and background noise control, combined with behavioral [(18)F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Subtractive analyses between conditions were used to identify brain regions involved in startle and PPI processing in well-hearing Black hooded rats. For correlative analysis with regard to the amount of PPI we also included hearing-impaired Lister hooded rats that startled more often, because their hearing threshold was just below the lowest prepulses. Metabolic imaging showed that the brain areas proposed for startle and PPI mediation are active during PPI paradigms in healthy untreated rats. More importantly, we show for the first time that the whole PPI modulation network is active during "passive" PPI sessions, where no selective attention to prepulse or startle stimulus is required. We conclude that this reflects ongoing monitoring of stimulus significance and constant adjustment of sensorimotor gating.

  4. Salicylate induced tinnitus: behavioral measures and neural activity in auditory cortex of awake rats.

    PubMed

    Yang, Guang; Lobarinas, Edward; Zhang, Liyan; Turner, Jeremy; Stolzberg, Daniel; Salvi, Richard; Sun, Wei

    2007-04-01

    Neurophysiological studies of salicylate-induced tinnitus have generally been carried out under anesthesia, a condition that abolishes the perception of tinnitus and depresses neural activity. To overcome these limitations, measurement of salicylate induced tinnitus were obtained from rats using schedule induced polydipsia avoidance conditioning (SIPAC) and gap pre-pulse inhibition of acoustic startle (GPIAS). Both behavioral measures indicated that tinnitus was present after treatment with 150 and 250 mg/kg of salicylate; measurements with GPIAS indicated that the pitch of the tinnitus was near 16 kHz. Chronically implanted microwire electrode arrays were used to monitor the local field potentials and spontaneous discharge rate from multiunit clusters in the auditory cortex of awake rats before and after treatment with 150 mg/kg of salicylate. The amplitude of the local field potential elicited with 60 dB SPL tone bursts increased significantly 2h after salicylate treatment particularly at 16-20 kHz; frequencies associated with the tinnitus pitch. Field potential amplitudes had largely recovered 1-2 days post-salicylate when behavioral results showed that tinnitus was absent. The mean spontaneous spike recorded from the same multiunit cluster pre- and post-salicylate decreased from 22 spikes/s before treatment to 14 spikes/s 2h post-salicylate and recovered 1 day post-treatment. These preliminary physiology data suggest that salicylate induced tinnitus is associated with sound evoked hyperactivity in auditory cortex and spontaneous hypoactivity.

  5. Irregular spiking of pyramidal neurons organizes as scale-invariant neuronal avalanches in the awake state

    PubMed Central

    Bellay, Timothy; Klaus, Andreas; Seshadri, Saurav; Plenz, Dietmar

    2015-01-01

    Spontaneous fluctuations in neuronal activity emerge at many spatial and temporal scales in cortex. Population measures found these fluctuations to organize as scale-invariant neuronal avalanches, suggesting cortical dynamics to be critical. Macroscopic dynamics, though, depend on physiological states and are ambiguous as to their cellular composition, spatiotemporal origin, and contributions from synaptic input or action potential (AP) output. Here, we study spontaneous firing in pyramidal neurons (PNs) from rat superficial cortical layers in vivo and in vitro using 2-photon imaging. As the animal transitions from the anesthetized to awake state, spontaneous single neuron firing increases in irregularity and assembles into scale-invariant avalanches at the group level. In vitro spike avalanches emerged naturally yet required balanced excitation and inhibition. This demonstrates that neuronal avalanches are linked to the global physiological state of wakefulness and that cortical resting activity organizes as avalanches from firing of local PN groups to global population activity. DOI: http://dx.doi.org/10.7554/eLife.07224.001 PMID:26151674

  6. Effects of lesions of the caudal cerebellar vermis on cardiovascular regulation in awake cats

    NASA Technical Reports Server (NTRS)

    Holmes, M. J.; Cotter, L. A.; Arendt, H. E.; Cass, S. P.; Yates, B. J.

    2002-01-01

    The vestibular system is known to participate in cardiovascular regulation during movement and postural alterations. The present study considered whether lesions of two regions of the posterior cerebellar vermis (the nodulus and uvula) that provide inputs to vestibular nucleus regions that affect control of blood pressure would alter cardiovascular responses during changes in posture. Blood pressure and heart rate were monitored in awake cats during nose-up tilts up to 60 degrees in amplitude before and following aspiration lesions of the nodulus or uvula; in most animals, cardiovascular responses were also recorded following the subsequent removal of vestibular inputs. Lesions of the nodulus or uvula did not affect baseline blood pressure or heart rate, although cardiovascular responses during nose-up tilts were altered. Increases in heart rate that typically occurred during 60 degrees nose-up tilt were attenuated in all three animals with lesions affecting both dorsal and ventral portions of the uvula; in contrast, the heart rate responses were augmented in the two animals with lesions mainly confined to the nodulus. Furthermore, following subsequent removal of vestibular inputs, uvulectomized animals, but not those with nodulus lesions, experienced more severe orthostatic hypotension than has previously been reported in cerebellum-intact animals with bilateral labyrinthectomies. These data suggest that the cerebellar nodulus and uvula modulate vestibulo-cardiovascular responses, although the two regions play different roles in cardiovascular regulation.

  7. Effect of geometric and motion tracking errors on awake small animal SPECT

    SciTech Connect

    Lee, Seung Joon; Baba, Justin S; Goddard Jr, James Samuel; Weisenberger, A G; Stolin, A; McKisson, J; Smith, M F

    2009-01-01

    A series of simulation studies were performed to evaluate the effects of geometric and motion tracking errors on reconstruction image quality for a single pinhole collimator awake animal imaging SPECT system. List-mode SPECT data generated using a custom Monte Carlo program that incorporated experimental mouse motion data were reconstructed by MLEM with Siddon's ray tracing. To better understand the impact of motion tracking and system geometric parameter errors on reconstructed system data, an offset of up to 1 mm or degree was separately applied to each for evaluation. In the absence of motion tracking or system geometric error, the applied motion compensation algorithm successfully reconstructed volumes without any degradation or distortion. Presented results reveal that motion tracking errors propagate through the SPECT reconstruction process. However, it is confirmed that the impact of tracking errors in the currently employed motion tracking system, is minimal because of their accuracy. The results also reveal the direct and indirect impact of geometric errors to motion compensated reconstruction quality and that a wrong assumption of pinhole transaxial position produces the most amount of distortion of all the investigated errors. Finally, system geometric errors are shown to have a greater impact on reconstruction quality than equivalent tracking errors.

  8. Effects of hypercapnia on variability of normal respiratory behavior in awake cats.

    PubMed

    Szlyk, P C; Jennings, D B

    1987-03-01

    Resting quiet awake cats breathing air in a steady state have a range of respiratory behavior, and this encompasses nonpurring and purring (D. B. Jennings and P. C. Szlyk, Can. J. Physiol. Pharmacol. 63: 148-154, 1985). On a given study day, individual cats usually breathed in a limited part of their potential respiratory range. Respiratory pattern, such as average breath frequency (f) and average tidal volume (VT) utilized for a given level of ventilation (V), could be predicted when cats breathed air; as well, inspiratory (TI) and expiratory (TE) times were specific for a given breath f. Inhalation of 2% and 4% CO2 in air caused an average increase in ventilation of 16 and 100%, respectively but breath-to-breath variability of V, f, and VT persisted at each fractional concentration of inspired CO2 (FICO2). The range of different V utilized breath to breath when breathing 2% CO2 overlapped with V during air control studies. Substantial overlap with control V also occurred in three of six cats when breathing 4% CO2. The most consistent effect of progressive hypercapnia was to increase VT and decrease f at a given level of V; increase in V during hypercapnia was accounted for by an increase in mean inspiratory flow (VT/TI). Hypercapnia also caused the fraction of breathing cycle devoted to inspiration (TI/TT) to increase at low f but not at high f.

  9. The role of awake craniotomy in reducing intraoperative visual field deficits during tumor surgery

    PubMed Central

    Wolfson, Racheal; Soni, Neil; Shah, Ashish H.; Hosein, Khadil; Sastry, Ananth; Bregy, Amade; Komotar, Ricardo J.

    2015-01-01

    Objective: Homonymous hemianopia due to damage to the optic radiations or visual cortex is a possible consequence of tumor resection involving the temporal or occipital lobes. The purpose of this review is to present and analyze a series of studies regarding the use of awake craniotomy (AC) to decrease visual field deficits following neurosurgery. Materials and Methods: A literature search was performed using the Medline and PubMed databases from 1970 and 2014 that compared various uses of AC other than intraoperative motor/somatosensory/language mapping with a focus on visual field mapping. Results: For the 17 patients analyzed in this study, 14 surgeries resulted in quadrantanopia, 1 in hemianopia, and 2 without visual deficits. Overall, patient satisfaction with AC was high, and AC was a means to reduce surgery-related complications and cost related with the procedure. Conclusion AC is a safe and tolerable procedure that can be used effectively to map optic radiations and the visual cortices in order to preserve visual function during resection of tumors infiltrating the temporal and occipital lobes. In the majority of cases, a homonymous hemianopia was prevented and patients were left with a quadrantanopia that did not interfere with daily function. PMID:26396597

  10. Neural correlates of sensorimotor gating: a metabolic positron emission tomography study in awake rats

    PubMed Central

    Rohleder, Cathrin; Jung, Fabienne; Mertgens, Hanna; Wiedermann, Dirk; Sué, Michael; Neumaier, Bernd; Graf, Rudolf; Leweke, F. Markus; Endepols, Heike

    2014-01-01

    Impaired sensorimotor gating occurs in neuropsychiatric disorders such as schizophrenia and can be measured using the prepulse inhibition (PPI) paradigm of the acoustic startle response. This assay is frequently used to validate animal models of neuropsychiatric disorders and to explore the therapeutic potential of new drugs. The underlying neural network of PPI has been extensively studied with invasive methods and genetic modifications. However, its relevance for healthy untreated animals and the functional interplay between startle- and PPI-related areas during a PPI session is so far unknown. Therefore, we studied awake rats in a PPI paradigm, startle control and background noise control, combined with behavioral [18F]fluoro-2-deoxyglucose positron emission tomography (FDG-PET). Subtractive analyses between conditions were used to identify brain regions involved in startle and PPI processing in well-hearing Black hooded rats. For correlative analysis with regard to the amount of PPI we also included hearing-impaired Lister hooded rats that startled more often, because their hearing threshold was just below the lowest prepulses. Metabolic imaging showed that the brain areas proposed for startle and PPI mediation are active during PPI paradigms in healthy untreated rats. More importantly, we show for the first time that the whole PPI modulation network is active during “passive” PPI sessions, where no selective attention to prepulse or startle stimulus is required. We conclude that this reflects ongoing monitoring of stimulus significance and constant adjustment of sensorimotor gating. PMID:24904330

  11. Effect of geometric and motion tracking error for awake small animal SPECT

    SciTech Connect

    S.J. Lee, J.S. Baba, J. S. Goddard, A. Stolin, J. McKisson, A.G. Weisenberger, M.F. Smith

    2010-01-01

    A series of simulation studies were performed to evaluate the effects of geometric and motion tracking errors on reconstruction image quality for a single pinhole collimator awake animal imaging SPECT system. List-mode SPECT data generated using a custom Monte Carlo program that incorporated experimental mouse motion data were reconstructed by MLEM with Siddon's ray tracing. To better understand the impact of motion tracking and system geometric parameter errors on reconstructed system data, an offset of up to 1 mm or degree was separately applied to each for evaluation. In the absence of motion tracking or system geometric error, the applied motion compensation algorithm successfully reconstructed volumes without any degradation or distortion. Presented results reveal that motion tracking errors propagate through the SPECT reconstruction process. However, it is confirmed that the impact of tracking errors in the currently employed motion tracking system, is minimal because of their accuracy. The results also reveal the direct and indirect impact of geometric errors to motion compensated reconstruction quality and that a wrong assumption of pinhole transaxial position produces the most amount of distortion of all the investigated errors. Finally, system geometric errors are shown to have a greater impact on reconstruction quality than equivalent tracking errors.

  12. Evaluation of gastrointestinal motility in awake rats: a learning exercise for undergraduate biomedical students.

    PubMed

    Souza, M A N; Souza, M H L P; Palheta, R C; Cruz, P R M; Medeiros, B A; Rola, F H; Magalhães, P J C; Troncon, L E A; Santos, A A

    2009-12-01

    Current medical curricula devote scarce time for practical activities on digestive physiology, despite frequent misconceptions about dyspepsia and dysmotility phenomena. Thus, we designed a hands-on activity followed by a small-group discussion on gut motility. Male awake rats were randomly submitted to insulin, control, or hypertonic protocols. Insulin and control rats were gavage fed with 5% glucose solution, whereas hypertonic-fed rats were gavage fed with 50% glucose solution. Insulin treatment was performed 30 min before a meal. All meals (1.5 ml) contained an equal mass of phenol red dye. After 10, 15, or 20 min of meal gavage, rats were euthanized. Each subset consisted of six to eight rats. Dye recovery in the stomach and proximal, middle, and distal small intestine was measured by spectrophotometry, a safe and reliable method that can be performed by minimally trained students. In a separate group of rats, we used the same protocols except that the test meal contained (99m)Tc as a marker. Compared with control, the hypertonic meal delayed gastric emptying and gastrointestinal transit, whereas insulinic hypoglycemia accelerated them. The session helped engage our undergraduate students in observing and analyzing gut motor behavior. In conclusion, the fractional dye retention test can be used as a teaching tool to strengthen the understanding of basic physiopathological features of gastrointestinal motility.

  13. Validation of a Modified Algometer to Measure Mechanical Nociceptive Thresholds in Awake Dogs

    PubMed Central

    Chen, Hui Cheng; Goh, Yong Meng; Abubakar, Adamu Abdul; Fakurazi, Sharida

    2015-01-01

    This study was conducted to validate the use of a modified algometer device to measure mechanical nociceptive thresholds in six dogs. Dogs were administered morphine intravenously (IV) at 1 mg/kg or saline at equivolume in a crossover design with one-week washout period. Mechanical nociceptive thresholds were determined before, after the administration of treatments at 5 minutes, and hourly for 8 hours. Thresholds were recorded at the carpal pad, metacarpal foot pad, tibia, femur, and abdomen. Heart rates, body temperature, and respiration were recorded at similar time points. Thresholds increased significantly (P < 0.05) from baseline values for up to 3 hours at tibia and abdomen, 4 hours at metacarpal pad, and 5 hours at the carpal pad and femur. Hypothermia, bradycardia, and change in respiration were observed in all dogs after morphine injection. Saline did not alter any threshold levels during the eight-hour study period, indicating no evidence of tolerance, learned avoidance, or local hyperaesthesia. The device and methods of testing were well tolerated by all the dogs. Results suggest that the modified algometer and method of application are useful to measure nociceptive mechanical thresholds in awake dogs. PMID:26075236

  14. RESPONSE PROPERTIES OF LOCAL FIELD POTENTIALS AND NEIGHBORING SINGLE NEURONS IN AWAKE PRIMARY VISUAL CORTEX

    PubMed Central

    Lashgari, Reza; Li, Xiaobing; Chen, Yao; Kremkow, Jens; Bereshpolova, Yulia; Swadlow, Harvey A.; Alonso, Jose M.

    2012-01-01

    Recordings from local field potentials (LFPs) are becoming increasingly common in research and clinical applications, however, we still have a poor understanding of how LFP stimulus selectivity originates from the combined activity of single neurons. Here, we systematically compared the stimulus selectivity of LFP and neighboring single unit activity (SUA) recorded in area V1 of awake primates. We demonstrate that LFP and SUA have similar stimulus preferences for orientation, direction of motion, contrast, size, temporal frequency and even spatial phase. However, the average SUA had 50 times better signal to noise, 20% higher contrast sensitivity, 45% higher direction selectivity and 15% more tuning depth than the average LFP. Low LFP frequencies (< 30 Hz) were most strongly correlated with the spiking frequencies of neurons with non-linear spatial summation and poor orientation/direction selectivity that were located near cortical current sinks (negative LFPs). In contrast, LFP gamma frequencies (> 30 Hz) were correlated with a more diverse group of neurons located near cortical sources (positive LFPs). In summary, our results indicate that low- and high-frequency LFP pools signals from V1 neurons with similar stimulus preferences but different response properties and cortical depths. PMID:22895722

  15. PET measured evoked cerebral blood flow responses in an awake monkey.

    PubMed

    Perlmutter, J S; Lich, L L; Margenau, W; Buchholz, S

    1991-03-01

    We have developed a method to measure task-related regional cerebral blood flow (BF) responses in an awake, trained monkey using positron emission tomography (PET) and H215O. We trained an animal with operant conditioning using only positive reinforcement to climb unassisted into a modified primate chair that was then positioned in the PET scanner. A special headholder and acrylic skull cap permitted precise placement and accurate repositioning. We measured BF qualitatively with bolus injection of H215O and 40-s scan. Each session included scans at rest interposed with scans during vibration of a forepaw. Regional responses were identified using subtraction image analysis. After global normalization, a resting image was subtracted on a pixel-by-pixel basis from a comparable image collected during vibration. The region of peak response occurred in contralateral sensorimotor cortex with a mean magnitude of 11.6% (+/- 3.2%) of the global mean value for 10 separate experiments, significantly greater than the mean qualitative BF change (0.4 +/- 3.6%; p less than 0.00001) in the same region for seven rest-rest pairs. This newly developed technique forms the basis for a wide variety of experiments.

  16. Inhibition shapes selectivity to vocalizations in the inferior colliculus of awake mice

    PubMed Central

    Mayko, Zachary M.; Roberts, Patrick D.; Portfors, Christine V.

    2012-01-01

    The inferior colliculus (IC) is a major center for integration of auditory information as it receives ascending projections from a variety of brainstem nuclei as well as descending projections from the thalamus and auditory cortex. The ascending projections are both excitatory and inhibitory and their convergence at the IC results in a microcircuitry that is important for shaping responses to simple, binaural, and modulated sounds in the IC. Here, we examined the role inhibition plays in shaping selectivity to vocalizations in the IC of awake, normal-hearing adult mice (CBA/CaJ strain). Neurons in the IC of mice show selectivity in their responses to vocalizations, and we hypothesized that this selectivity is created by inhibitory microcircuitry in the IC. We compared single unit responses in the IC to pure tones and a variety of ultrasonic mouse vocalizations before and after iontophoretic application of GABAA receptor (GABAAR) and glycine receptor (GlyR) antagonists. The most pronounced effects of blocking GABAAR and GlyR on IC neurons were to increase spike rates and broaden excitatory frequency tuning curves in response to pure tone stimuli, and to decrease selectivity to vocalizations. Thus, inhibition plays an important role in creating selectivity to vocalizations in the IC. PMID:23087616

  17. Long-term potentiation and evoked spike responses in the cingulate cortex of freely mobile rats.

    PubMed

    Gorkin, A G; Reymann, K G; Aleksandrov, Yu I

    2003-10-01

    Long-term potentiation of synaptic efficiency is regarded as a major candidate for the role of the physiological mechanism of long-term memory. However, the limited development of concepts of the cellular and subcellular characteristics of the induction of long-term potentiation in animals in conditions of free behavior does not correspond to the importance of this question. The present study was undertaken to determine whether the characteristics of potentiation in the cingulate cortex in response to stimulation of fibers of the subiculo-cingulate tract are truly long-term, i.e., develop through all known phases and last at least 24 h, in freely moving animals. In addition, the study aims included identification of the effects of application of blockers of different types of glutamate receptors on the development of long-term potentiation and identification of the characteristics of spike responses of single cingulate cortex neurons to stimulation of the subiculo-cingulate tract. Long-term potentiation, lasting more than 24 h, was obtained in freely moving adult rats not treated with GABA blockers. Injection of glutamate NMDA synapse blockers led to significant decreases in evoked cingulate cortex potentials in response to test stimulation. Activatory short-latency spike responses were characterized by a low probability of spike generation, and this increased with increases in the stimulation current. These data demonstrated that it is methodologically possible to compare, in freely moving rats, the involvement of individual neurons in the mechanisms involved in learning one or another type of adaptive behavior and the dynamics of their evoked spike activity during the formation of long-term potentiation. PMID:14635990

  18. Preliminary research on abnormal brain detection by wavelet-energy and quantum- behaved PSO.

    PubMed

    Zhang, Yudong; Ji, Genlin; Yang, Jiquan; Wang, Shuihua; Dong, Zhengchao; Phillips, Preetha; Sun, Ping

    2016-04-29

    It is important to detect abnormal brains accurately and early. The wavelet-energy (WE) was a successful feature descriptor that achieved excellent performance in various applications; hence, we proposed a WE based new approach for automated abnormal detection, and reported its preliminary results in this study. The kernel support vector machine (KSVM) was used as the classifier, and quantum-behaved particle swarm optimization (QPSO) was introduced to optimize the weights of the SVM. The results based on a 5 × 5-fold cross validation showed the performance of the proposed WE + QPSO-KSVM was superior to ``DWT + PCA + BP-NN'', ``DWT + PCA + RBF-NN'', ``DWT + PCA + PSO-KSVM'', ``WE + BPNN'', ``WE +$ KSVM'', and ``DWT $+$ PCA $+$ GA-KSVM'' w.r.t. sensitivity, specificity, and accuracy. The work provides a novel means to detect abnormal brains with excellent performance. PMID:27163327

  19. Preliminary research on abnormal brain detection by wavelet-energy and quantum- behaved PSO.

    PubMed

    Zhang, Yudong; Ji, Genlin; Yang, Jiquan; Wang, Shuihua; Dong, Zhengchao; Phillips, Preetha; Sun, Ping

    2016-04-29

    It is important to detect abnormal brains accurately and early. The wavelet-energy (WE) was a successful feature descriptor that achieved excellent performance in various applications; hence, we proposed a WE based new approach for automated abnormal detection, and reported its preliminary results in this study. The kernel support vector machine (KSVM) was used as the classifier, and quantum-behaved particle swarm optimization (QPSO) was introduced to optimize the weights of the SVM. The results based on a 5 × 5-fold cross validation showed the performance of the proposed WE + QPSO-KSVM was superior to ``DWT + PCA + BP-NN'', ``DWT + PCA + RBF-NN'', ``DWT + PCA + PSO-KSVM'', ``WE + BPNN'', ``WE +$ KSVM'', and ``DWT $+$ PCA $+$ GA-KSVM'' w.r.t. sensitivity, specificity, and accuracy. The work provides a novel means to detect abnormal brains with excellent performance.

  20. Precise rhythmicity in activity of neocortical, thalamic and brain stem neurons in behaving cats and rabbits.

    PubMed

    Dunin-Barkowski, Witali L; Sirota, Mikhail G; Lovering, Andrew T; Orem, John M; Vidruk, Edward H; Beloozerova, Irina N

    2006-11-25

    Rhythmic discharges of neurons are believed to be involved in information processing in both sensory and motor systems. However their fine structure and functional role need further elucidation. We employed a pattern-based approach to search for episodes of precisely rhythmic activity of single neurons recorded in different brain structures in behaving cats and rabbits. We defined discharge patterns using an algorithmic description, which is different from the previously suggested template methods. We detected episodes of precisely rhythmic discharges, specifically, triads of constant (precision +/-2.5%) inter-spike intervals in the 10-70 ms range. In 54% (67/125) of neurons tested, these patterns could not be explained by random occurrences or by steady or slowly changing input. Rhythmic patterns occurred at a wide range of inter-spike intervals, and were imbedded in non-rhythmic activity. In many neurons, timing of these precisely rhythmic patterns was related to different locomotion tasks or to respiration.

  1. Relativistic electron scattering from a freely movable proton in a strong laser field

    NASA Astrophysics Data System (ADS)

    Liu, Ai-Hua; Li, Shu-Min

    2014-11-01

    We study the electron scattering from the freely movable spin-1/2 proton in the presence of a linearly polarized laser field in the first Born approximation. The dressed state of the electron is described by a time-dependent wave function derived from a perturbation treatment (in a laser field). With the aid of numerical results we explore the dependencies of the differential cross section (DCS) on the electron-impact energy. Due to the mobility of the target, the DCS of this process is modified compared to the Mott scattering, especially in large scattering angles.

  2. Humidity distribution affected by freely exposed water surfaces: Simulations and experimental verification

    NASA Astrophysics Data System (ADS)

    Hygum, M. A.; Popok, V. N.

    2014-07-01

    Accurate models for the water vapor flux at a water-air interface are required in various scientific, reliability and civil engineering aspects. Here, a study of humidity distribution in a container with air and freely exposed water is presented. A model predicting a spatial distribution and time evolution of relative humidity based on statistical rate theory and computational fluid dynamics is developed. In our approach we use short-term steady-state steps to simulate the slowly evolving evaporation in the system. Experiments demonstrate considerably good agreement with the computer modeling and allow one to distinguish the most important parameters for the model.

  3. [Freely moving circular shadows in the abdominal cavity--the exudative enteropathy syndrome?].

    PubMed

    Majorová, E; Böör, A; Beno, P; Drahovský, P; Krajcár, R

    1993-12-01

    The authors describe a 14-year-old gypsy girl with the clinical picture of exudative enteropathy where they observed on X-ray examination of the abdominal cavity circular formations which changed position. On laparotomy they found on the serous membrane of the entire enlarged and inflamed ileum numerous pseudo-polypous formations the majority of which were released and floated freely in the chylous ascites. The description of similar globular lesions of the lymphatic system was found in the literature only in accounts on post-mortem findings. PMID:8137446

  4. Trapped modes around freely floating bodies in a two-layer fluid channel

    PubMed Central

    Cal, Filipe S.; Dias, Gonçalo A. S.; Videman, Juha H.

    2014-01-01

    Unlike the trapping of time-harmonic water waves by fixed obstacles, the oscillation of freely floating structures gives rise to a complex nonlinear spectral problem. Still, through a convenient elimination scheme the system simplifies to a linear spectral problem for a self-adjoint operator in a Hilbert space. Under symmetry assumptions on the geometry of the fluid domain, we present conditions guaranteeing the existence of trapped modes in a two-layer fluid channel. Numerous examples of floating bodies supporting trapped modes are given. PMID:25294970

  5. Trapped modes around freely floating bodies in a two-layer fluid channel.

    PubMed

    Cal, Filipe S; Dias, Gonçalo A S; Videman, Juha H

    2014-10-01

    Unlike the trapping of time-harmonic water waves by fixed obstacles, the oscillation of freely floating structures gives rise to a complex nonlinear spectral problem. Still, through a convenient elimination scheme the system simplifies to a linear spectral problem for a self-adjoint operator in a Hilbert space. Under symmetry assumptions on the geometry of the fluid domain, we present conditions guaranteeing the existence of trapped modes in a two-layer fluid channel. Numerous examples of floating bodies supporting trapped modes are given.

  6. PROGRAM DROP: A computer program for prediction of evaporation from freely falling multicomponent drops

    SciTech Connect

    Gavin, P.M.

    1996-12-01

    PROGRAM DROP consists of a series of FORTRAN routine which together are used to model the evaporation of a freely falling, multicomponent drop composed of an arbitrary number of volatile species and a single nonvolatile, inert component. The physics underlying the model are clearly identified, and the model`s relationship to previous work in the literature is described. Test cases are used to illustrate the viability of the model and to highlight its potential usefulness in the accurate prediction of multicomponent droplet vaporization in a variety of applications.

  7. Theta phase classification of interneurons in the hippocampal formation of freely moving rats.

    PubMed

    Czurkó, András; Huxter, John; Li, Yu; Hangya, Balázs; Muller, Robert U

    2011-02-23

    Earlier work on freely moving rats classified neurons in Ammon's horn as pyramidal cells (including place cells) or interneurons (previously called "theta cells") based on temporal discharge correlates and waveform configurations, but the anatomical and biochemical diversity of interneurons suggests they may have other distinguishing characteristics. To explore this possibility, we made extracellular recordings as rats foraged for food in an open space, used accepted criteria to identify interneurons, and found two additional categorization methods. First, interneurons were separated into theta-modulated and theta-independent groups using spike autocorrelograms. Second, theta-modulated interneurons were further separated into four groups by the phase of the ∼8 Hz theta rhythm at which firing was most rapid. These phase groups resemble the four phase peak groups of five anatomically identified interneuron types (two with the same preferred phase) recorded during the slow (∼4 Hz) theta rhythm in urethane-anesthetized rats. We suggest that the similar number of peak phase groups in walking rats and urethane-anesthetized rats and the partial agreement between peak phase values reflect a similar organization of theta rhythm in both states, so that the discharge properties of anatomically identified interneurons can be described in freely moving rats. Interestingly, the average spatial firing precision of the interneuron classes does not differ significantly, suggesting that the strong location-specific firing of place cells may be due to segregated high- and low-precision interneuron ensembles rather than to one or more dedicated high-precision classes.

  8. Single-molecule-sensitive fluorescence resonance energy transfer in freely-diffusing attoliter droplets

    SciTech Connect

    Rahmanseresht, Sheema; Ramos, Kieran P.; Gamari, Ben D.; Goldner, Lori S.; Milas, Peker

    2015-05-11

    Fluorescence resonance energy transfer (FRET) from individual, dye-labeled RNA molecules confined in freely-diffusing attoliter-volume aqueous droplets is carefully compared to FRET from unconfined RNA in solution. The use of freely-diffusing droplets is a remarkably simple and high-throughput technique that facilitates a substantial increase in signal-to-noise for single-molecular-pair FRET measurements. We show that there can be dramatic differences between FRET in solution and in droplets, which we attribute primarily to an altered pH in the confining environment. We also demonstrate that a sufficient concentration of a non-ionic surfactant mitigates this effect and restores FRET to its neutral-pH solution value. At low surfactant levels, even accounting for pH, we observe differences between the distribution of FRET values in solution and in droplets which remain unexplained. Our results will facilitate the use of nanoemulsion droplets as attoliter volume reactors for use in biophysical and biochemical assays, and also in applications such as protein crystallization or nanoparticle synthesis, where careful attention to the pH of the confined phase is required.

  9. Continuous Force Decoding from Local Field Potentials of the Primary Motor Cortex in Freely Moving Rats

    PubMed Central

    Khorasani, Abed; Heydari Beni, Nargess; Shalchyan, Vahid; Daliri, Mohammad Reza

    2016-01-01

    Local field potential (LFP) signals recorded by intracortical microelectrodes implanted in primary motor cortex can be used as a high informative input for decoding of motor functions. Recent studies show that different kinematic parameters such as position and velocity can be inferred from multiple LFP signals as precisely as spiking activities, however, continuous decoding of the force magnitude from the LFP signals in freely moving animals has remained an open problem. Here, we trained three rats to press a force sensor for getting a drop of water as a reward. A 16-channel micro-wire array was implanted in the primary motor cortex of each trained rat, and obtained LFP signals were used for decoding of the continuous values recorded by the force sensor. Average coefficient of correlation and the coefficient of determination between decoded and actual force signals were r = 0.66 and R2 = 0.42, respectively. We found that LFP signal on gamma frequency bands (30–120 Hz) had the most contribution in the trained decoding model. This study suggests the feasibility of using low number of LFP channels for the continuous force decoding in freely moving animals resembling BMI systems in real life applications. PMID:27767063

  10. Virally mediated optogenetic excitation and inhibition of pain in freely moving non-transgenic mice

    PubMed Central

    Iyer, Shrivats Mohan; Montgomery, Kate L.; Towne, Chris; Lee, Soo Yeun; Ramakrishnan, Charu; Deisseroth, Karl; Delp, Scott L.

    2014-01-01

    Primary nociceptors are the first neurons involved in the complex processing system that regulates normal and pathological pain1. Our ability to excite and inhibit these neurons has been limited by pharmacological and electrical stimulation constraints; non-invasive excitation and inhibition of these neurons in freely moving non-transgenic animals has not been possible. Here we use an optogenetic2 strategy to bidirectionally control nociceptors of non-transgenic mice. Intra-sciatic nerve injection of adeno-associated viruses encoding an excitatory opsin enabled light-inducible stimulation of acute pain, place aversion, and optogenetically mediated reductions in withdrawal thresholds to mechanical and thermal stimuli. In contrast, viral delivery of an inhibitory opsin enabled light-inducible inhibition of acute pain perception, and reversed mechanical allodynia and thermal hyperalgesia in a model of neuropathic pain. Light was delivered transdermally enabling these behaviors to be induced in freely moving animals. This approach may have utility in basic and translational pain research, and enable rapid drug screening and testing of newly engineered opsins. PMID:24531797

  11. HermesC: low-power wireless neural recording system for freely moving primates.

    PubMed

    Chestek, Cynthia A; Gilja, Vikash; Nuyujukian, Paul; Kier, Ryan J; Solzbacher, Florian; Ryu, Stephen I; Harrison, Reid R; Shenoy, Krishna V

    2009-08-01

    Neural prosthetic systems have the potential to restore lost functionality to amputees or patients suffering from neurological injury or disease. Current systems have primarily been designed for immobile patients, such as tetraplegics functioning in a rather static, carefully tailored environment. However, an active patient such as amputee in a normal dynamic, everyday environment may be quite different in terms of the neural control of movement. In order to study motor control in a more unconstrained natural setting, we seek to develop an animal model of freely moving humans. Therefore, we have developed and tested HermesC-INI3, a system for recording and wirelessly transmitting neural data from electrode arrays implanted in rhesus macaques who are freely moving. This system is based on the integrated neural interface (INI3) microchip which amplifies, digitizes, and transmits neural data across a approximately 900 MHz wireless channel. The wireless transmission has a range of approximately 4 m in free space. All together this device consumes 15.8 mA and 63.2 mW. On a single 2 A-hr battery pack, this device runs contiguously for approximately six days. The smaller size and power consumption of the custom IC allows for a smaller package (51 x 38 x 38 mm (3)) than previous primate systems. The HermesC-INI3 system was used to record and telemeter one channel of broadband neural data at 15.7 kSps from a monkey performing routine daily activities in the home cage.

  12. The total and freely dissolved polycyclic aromatic hydrocarbons content in residues from biogas production.

    PubMed

    Stefaniuk, Magdalena; Oleszczuk, Patryk

    2016-01-01

    In the situation of increasing agricultural utilization of residues from biogas production (RBP) it is important to determine the concentration of contaminants, which could occur in these materials. The group of contaminants that requires special attention are polycyclic aromatic hydrocarbons (PAH). The objective of the study was to determine the total and freely dissolved (Cfree) of PAHs in RBP from 6 different biogas plants operating under various temperature conditions and without or with the separation into the solid and liquid fractions. The freely dissolved PAHs were determined using polyoxymethylene (POM method). The total content of the Σ16 PAHs in RBP varied from 449 to 6147 μg/kgdw, while that of Cfree PAHs was at the level from 57 to 653 ng/L. No significant differences were noted in the content of the Σ16 PAHs (total) between the solid and the liquid fractions. This indicates that in the course of the separation, the PAHs are distributed proportionally between the fractions. However in the case of Cfree, PAHs content in the solid fraction was over twice as high as in the liquid fraction. This was probably due to the greater affinity of the particles present in the liquid fraction to the analysed PAHs than to the particles of the solid fraction. Higher affinity to liquid fraction was also confirmed by the distribution coefficients KTOC determined on the basis of Cfree.

  13. Wireless inertial measurement of head kinematics in freely-moving rats

    PubMed Central

    Pasquet, Matthieu O.; Tihy, Matthieu; Gourgeon, Aurélie; Pompili, Marco N.; Godsil, Bill P.; Léna, Clément; Dugué, Guillaume P.

    2016-01-01

    While miniature inertial sensors offer a promising means for precisely detecting, quantifying and classifying animal behaviors, versatile inertial sensing devices adapted for small, freely-moving laboratory animals are still lacking. We developed a standalone and cost-effective platform for performing high-rate wireless inertial measurements of head movements in rats. Our system is designed to enable real-time bidirectional communication between the headborne inertial sensing device and third party systems, which can be used for precise data timestamping and low-latency motion-triggered applications. We illustrate the usefulness of our system in diverse experimental situations. We show that our system can be used for precisely quantifying motor responses evoked by external stimuli, for characterizing head kinematics during normal behavior and for monitoring head posture under normal and pathological conditions obtained using unilateral vestibular lesions. We also introduce and validate a novel method for automatically quantifying behavioral freezing during Pavlovian fear conditioning experiments, which offers superior performance in terms of precision, temporal resolution and efficiency. Thus, this system precisely acquires movement information in freely-moving animals, and can enable objective and quantitative behavioral scoring methods in a wide variety of experimental situations. PMID:27767085

  14. Freely chosen stride frequencies during walking and running are not correlated with freely chosen pedalling frequency and are insensitive to strength training.

    PubMed

    Sardroodian, Mahta; Madeleine, Pascal; Voigt, Michael; Hansen, Ernst A

    2015-06-01

    Despite biomechanical differences between walking, running, and cycling, these types of movement are supposedly generated by shared neural networks. According to this hypothesis, we investigated relationships between movement frequencies in these tasks as well as effects of strength training on locomotion behaviour. The movement frequencies during walking, running, and cycling were 58.1±2.6 strides min(-1), 81.3±4.4 strides min(-1), and 77.2±11.5 revolutions min(-1), respectively (n=27). Stride frequencies in walking and running correlated positively (r=0.72, p<0.001) while no significant correlations were found between stride frequencies during walking and running, respectively, and pedalling frequency (r=0.16, p=0.219 and r=0.04, p=0.424). Potential changes in the freely chosen stride frequencies and stride phase characteristics were also investigated during walking and running through 4 weeks of (i) hip extension strength training (n=9), (ii) hip flexion strength training (n=9), and (iii) no intervention (n=9). Results showed that stride characteristics were unaffected by strength training. That is in contrast to previous observations of decreased pedalling frequency following strength training. In total, these results are proposed to indicate that walking and running movements are robustly generated due to an evolutionary consolidation of the interaction between the musculoskeletal system and neural networks. Further, based on the present results, and the fact that cycling is a postnatally developed task that likely results in a different pattern of descending and afferent input to rhythm generating neural networks than walking and running, we propose pedalling to be generated by neural networks mainly consolidated for locomotion.

  15. Excitation and Inhibition Compete to Control Spiking during Hippocampal Ripples: Intracellular Study in Behaving Mice

    PubMed Central

    English, Daniel F.; Peyrache, Adrien; Stark, Eran; Roux, Lisa; Vallentin, Daniela; Long, Michael A.

    2014-01-01

    High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation of the rhythm and the recruitment of spikes from pyramidal neurons are still poorly understood. Using intracellular, sharp electrode recordings in freely moving, drug-free mice, we observed consistent large depolarizations in CA1 pyramidal cells during sharp wave ripples, which are associated with ripple frequency fluctuation of the membrane potential (“intracellular ripple”). Despite consistent depolarization, often exceeding pre-ripple spike threshold values, current pulse-induced spikes were strongly suppressed, indicating that spiking was under the control of concurrent shunting inhibition. Ripple events were followed by a prominent afterhyperpolarization and spike suppression. Action potentials during and outside ripples were orthodromic, arguing against ectopic spike generation, which has been postulated by computational models of ripple generation. These findings indicate that dendritic excitation of pyramidal neurons during ripples is countered by shunting of the membrane and postripple silence is mediated by hyperpolarizing inhibition. PMID:25471587

  16. Deep brain optical measurements of cell type–specific neural activity in behaving mice

    PubMed Central

    Cui, Guohong; Jun, Sang Beom; Jin, Xin; Luo, Guoxiang; Pham, Michael D; Lovinger, David M; Vogel, Steven S; Costa, Rui M

    2014-01-01

    Recent advances in genetically encoded fluorescent sensors enable the monitoring of cellular events from genetically defined groups of neurons in vivo. In this protocol, we describe how to use a time-correlated single-photon counting (tcspc)–based fiber optics system to measure the intensity, emission spectra and lifetime of fluorescent biosensors expressed in deep brain structures in freely moving mice. When combined with cre-dependent selective expression of genetically encoded ca2+ indicators (GecIs), this system can be used to measure the average neural activity from a specific population of cells in mice performing complex behavioral tasks. as an example, we used viral expression of GcaMps in striatal projection neurons (spns) and recorded the fluorescence changes associated with calcium spikes from mice performing a lever-pressing operant task. the whole procedure, consisting of virus injection, behavior training and optical recording, takes 3–4 weeks to complete. With minor adaptations, this protocol can also be applied to recording cellular events from other cell types in deep brain regions, such as dopaminergic neurons in the ventral tegmental area. the simultaneously recorded fluorescence signals and behavior events can be used to explore the relationship between the neural activity of specific brain circuits and behavior. PMID:24784819

  17. Excitation and inhibition compete to control spiking during hippocampal ripples: intracellular study in behaving mice.

    PubMed

    English, Daniel F; Peyrache, Adrien; Stark, Eran; Roux, Lisa; Vallentin, Daniela; Long, Michael A; Buzsáki, György

    2014-12-01

    High-frequency ripple oscillations, observed most prominently in the hippocampal CA1 pyramidal layer, are associated with memory consolidation. The cellular and network mechanisms underlying the generation of the rhythm and the recruitment of spikes from pyramidal neurons are still poorly understood. Using intracellular, sharp electrode recordings in freely moving, drug-free mice, we observed consistent large depolarizations in CA1 pyramidal cells during sharp wave ripples, which are associated with ripple frequency fluctuation of the membrane potential ("intracellular ripple"). Despite consistent depolarization, often exceeding pre-ripple spike threshold values, current pulse-induced spikes were strongly suppressed, indicating that spiking was under the control of concurrent shunting inhibition. Ripple events were followed by a prominent afterhyperpolarization and spike suppression. Action potentials during and outside ripples were orthodromic, arguing against ectopic spike generation, which has been postulated by computational models of ripple generation. These findings indicate that dendritic excitation of pyramidal neurons during ripples is countered by shunting of the membrane and postripple silence is mediated by hyperpolarizing inhibition.

  18. The conjugacy of the vestibulo-ocular reflex evoked by single labyrinth stimulation in awake monkeys.

    PubMed

    Tang, Xuehui; Xu, Youguo; Simpson, Ivra; Jeffcoat, Ben; Mustain, William; Zhou, Wu

    2010-10-01

    It is well known that the vestibulo-ocular reflex (VOR) is conjugate when measured in the dark with minimal vergence. But the neural basis of the VOR conjugacy remains to be identified. In the present study, we measured the VOR conjugacy during single labyrinth stimulation to examine whether the VOR conjugacy depends on reciprocal stimulation of the two labyrinths. There are conflicting views on this issue. First, since the vestibular signals carried by the ascending tract of Deiters' are distributed exclusively to the motoneurons of the ipsilateral eye, the neural innervations after single labyrinth stimulation are not symmetrical for the two eyes. Thus, single labyrinth stimulation may generate disjunctive VOR responses. Second, the only published study on this issue was an electrooculography (EOG) study that reported disjunctive VOR responses during unilateral caloric irrigation (Wolfe in Ann Otol 88:79-85, 1979). Third, the VOR during unilateral caloric stimulation performed in clinical vestibular tests is routinely perceived to be conjugate. To resolve these conflicting views, the present study examined the VOR conjugacy during single labyrinth stimulation by recording binocular eye position signals in awake monkeys with a search coil technique. In contradiction to the previous EOG study and the prediction based on the asymmetry of the unilateral brainstem VOR circuits, we found that the VOR during unilateral caloric irrigation was conjugate over a wide range of conditions. We conclude that the net neural innervations received by the two eyes are symmetrical after single labyrinth stimulation, despite the apparent asymmetry in the unilateral VOR pathways. A novel role for the ascending tract of Deiters' in the VOR conjugacy is proposed.

  19. Alveolar data in healthy, awake neonates during spontaneous ventilation: a preliminary investigation.

    PubMed

    Lagneaux, D; Mossay, C; Geubelle, F; Christiaens, G

    1988-01-01

    A computerized method for the measurement of alveolar ventilation (VA) and the mean alveolar partial pressures of CO2 and O2 is described and tested in healthy, awake fullterm (FT) newborns and preterm (PT) infants (postnatal age 40 days). This study emphasizes the technical pitfalls generally encountered when dealing with very small infants. A sensitive pneumotachograph with a small dead space volume and a low-flow sampling system for the gas analyzer are minimum requirements. Under these technical conditions, the major problem is the scanning time of the mass spectrometer (50 Hz), which fixes the time constant, as well as the digitization sampling rate of the gas signals. This rate was not sufficient when the respiratory rate was above 90 min-1. As critical visual evaluation of each breath is required, fully automatic access to mean alveolar data is not possible. The mean dead-space volume in both FT and PT infants was 2 ml.kg-1, with a VD/VT ratio of 0.3. The mean alveolar point was 2/3 VT, as found in adults. When expressed as ml.min-1.kg-1, VA appeared to be higher than in other studies, but related to the metabolic requirements. (VCO2 = 7.8 +/- 0.2 ml.min-1.kg-1 and VO2 = 8.0 +/- 0.2 ml.min-1.kg-1), in accordance with the state of vigilance of the neonates. Indeed, the PACO2 values, which depend on the ratio VCO2/VA, are in agreement with the values of PaCO2 generally considered normal in healthy newborns over 1 week of age.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3237450

  20. Techniques for collecting saliva from awake, unrestrained, adult monkeys for cortisol assay.

    PubMed

    Lutz, C K; Tiefenbacher, S; Jorgensen, M J; Meyer, J S; Novak, M A

    2000-10-01

    Cortisol levels serve as an index of pituitary-adrenal activity in nonhuman primates. In adult monkeys, cortisol is normally measured in blood (typically requiring restraint or sedation) or urine (reflecting a state rather than point estimate). In contrast, saliva collection is less invasive than drawing blood and allows for repeated sampling within a short period of time. Although protocols exist for collecting saliva from young monkeys, these procedures are inadequate for awake, unrestrained adult animals. Our laboratory has developed two methods for collecting saliva from adult rhesus monkeys: a "screen" method, which involves licking screen-covered gauze, and a "pole" method, which involves sucking and chewing on an attached rope. Twenty-three adult male rhesus monkeys were used to evaluate these two methods. After a period of adaptation, saliva samples were collected from 21 of 23 subjects. Saliva collection was faster with the pole than with the screen method (P < 0.01), but the pole method was not suitable for some animals because of their tendency to bite off the attached rope. An analysis of 19 saliva samples revealed a mean cortisol concentration of 0.84 microg/dl (range 0.27-1.77 microg/dl). There was no statistically significant difference in cortisol value between methods used (P > 0.22). The influence of the flavoring on the cortisol assay was tested, and was found to have no significant effect (P > 0.28). Our results indicate that either technique can be used to safely collect saliva from unrestrained adult monkeys. Choice of technique will depend on the proclivities of individual monkeys.

  1. Thalamocortical control of feed-forward inhibition in awake somatosensory 'barrel' cortex.

    PubMed Central

    Swadlow, Harvey A

    2002-01-01

    Intracortical inhibition plays a role in shaping sensory cortical receptive fields and is mediated by both feed-forward and feedback mechanisms. Feed-forward inhibition is the faster of the two processes, being generated by inhibitory interneurons driven by monosynaptic thalamocortical (TC) input. In principle, feed-forward inhibition can prevent targeted cortical neurons from ever reaching threshold when TC input is weak. To do so, however, inhibitory interneurons must respond to TC input at low thresholds and generate spikes very quickly. A powerful feed-forward inhibition would sharpen the tuning characteristics of targeted cortical neurons, and interneurons with sensitive and broadly tuned receptive fields could mediate this process. Suspected inhibitory interneurons (SINs) with precisely these properties are found in layer 4 of the somatosensory (S1) 'barrel' cortex of rodents and rabbits. These interneurons lack the directional selectivity seen in most cortical spiny neurons and in ventrobasal TC afferents, but are much more sensitive than cortical spiny neurons to low-amplitude whisker displacements. This paper is concerned with the activation of S1 SINs by TC impulses, and with the consequences of this activation. Multiple TC neurons and multiple S1 SINs were simultaneously studied in awake rabbits, and cross-correlation methods were used to examine functional connectivity. The results demonstrate a potent, temporally precise, dynamic and highly convergent/divergent functional input from ventrobasal TC neurons to SINs of the topographically aligned S1 barrel. Whereas the extensive pooling of convergent TC inputs onto SINs generates sensitive and broadly tuned inhibitory receptive fields, the potent TC divergence onto many SINs generates sharply synchronous activity among these elements. This TC feed-forward inhibitory network is well suited to provide a fast, potent, sensitive and broadly tuned inhibition of targeted spiny neurons that will suppress spike

  2. Downregulation of the cough reflex by aclidinium and tiotropium in awake and anesthetized rabbits.

    PubMed

    Mutolo, Donatella; Cinelli, Elenia; Iovino, Ludovica; Pantaleo, Tito; Bongianni, Fulvia

    2016-06-01

    Long-acting muscarinic receptor antagonists (LAMAs) have been reported to attenuate cough in preclinical and clinical studies. The present study was performed on rabbits to compare aclidinium and tiotropium efficacy in the downregulation of the cough reflex. This reflex was evoked by citric acid inhalation in unanesthetized animals and by both citric acid inhalation and mechanical stimulation of the tracheobronchial tree in anesthetized animals 90 min following the inhalation of each drug (nebulizer output always at 1 mL/min). Aclidinium 4 mg/mL and tiotropium 200 μg/mL inhaled in 1 min proved to have similar protective effect on methacholine-induced bronchoconstriction in anesthetized animals. The total dosage employed for aclidinium and tiotropium was 4 mg and 200 μg, respectively. In awake animals, similar reductions in the cough number were observed following 10-min inhalation of each drug with a slight, not significant tendency to higher antitussive effects for aclidinium. In anesthetized animals, 1-min inhalation of each drug caused similar depressant effects on cough responses induced by both mechanical and chemical stimulation. A complete suppression of cough responses to mechanical stimuli was seen in some preparations. The results strongly suggest that the LAMA-induced downregulation of cough may be mediated not only by transient receptor potential vanilloid type 1 channels, as already reported, but also by acid-sensing ion channels and mechanoreceptors. The route of administration along with the more rapid hydrolysis of aclidinium into inactive metabolites minimize potential systemic side effects and give to this drug a very favorable safety profile. PMID:27080033

  3. Nitric oxide modulates the cardiovascular effects elicited by acetylcholine in the NTS of awake rats.

    PubMed

    da Silva, Liana Gouveia; Dias, Ana Carolina Rodrigues; Furlan, Elaina; Colombari, Eduardo

    2008-12-01

    Microinjection of acetylcholine chloride (ACh) in the nucleus of the solitary tract (NTS) of awake rats caused a transient and dose-dependent hypotension and bradycardia. Because it is known that cardiovascular reflexes are affected by nitric oxide (NO) produced in the NTS, we investigated whether these ACh-induced responses depend on NO in the NTS. Responses to ACh (500 pmol in 100 nl) were strongly reduced by ipsilateral microinjection of the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10 nmol in 100 nl) in the NTS: mean arterial pressure (MAP) fell by 50 +/- 5 mmHg before L-NAME to 9 +/- 4 mmHg, 10 min after L-NAME, and HR fell by 100 +/- 26 bpm before L-NAME to 20 +/- 10 bpm, 10 min after L-NAME (both P < 0.05). Microinjection of the selective inhibitor of neuronal nitric oxide synthase (nNOS), 1-(2-trifluoromethylphenyl) imidazole (TRIM; 13.3 nmol in 100 nl), in the NTS also reduced responses to ACh: MAP fell from 42 +/- 3 mmHg before TRIM to 27 +/- 6 mmHg, 10 min after TRIM (P < 0.05). TRIM also tended to reduce ACh-induced bradycardia, but this effect was not statistically significant. ACh-induced hypotension and bradycardia returned to control levels 30-45 min after NOS inhibition. Control injections with D-NAME and saline did not affect resting values or the response to ACh. In conclusion, injection of ACh into the NTS of conscious rats induces hypotension and bradycardia, and these effects may be mediated at least partly by NO produced in NTS neurons.

  4. Dexmedetomidine provides optimum conditions during awake fiberoptic intubation in simulated cervical spine injury patients

    PubMed Central

    Chopra, Pooja; Dixit, Madhu Bala; Dang, Aashish; Gupta, Vibhuti

    2016-01-01

    Background and Aims: We undertook this study to assess if a small-dose of dexmedetomidine (DEX) for conscious sedation during awake fiberoptic intubation (AFOI) in simulated cervical spine injury (CSI) patients provides optimum conditions and fulfills the need of postintubation neurological examination required in such patients. The aim was to assess the efficacy of DEX on arousability and patient's comfort during AFOI in simulated CSI patients. Material and Methods: In this prospective, randomized double-blind study, 100 American Society of Anesthesiologists Grade I-II patients aged between 18 and 65 years scheduled for elective surgery under general anesthesia underwent AFOI under conscious sedation with DEX. After locally anesthetizing the airway and applying a cervical collar, patients either received DEX 1 μg/kg over 10 min followed by 0.7 μg/kg/h maintenance infusion or normal saline in the same dose and rate during AFOI. Targeted sedation (Ramsay sedation score [RSS] ≥2) during AFOI was maintained with midazolam [MDZ] in both groups. Statistical Analysis was performed using unpaired Student's t-test, Chi-square test, Mann-Whitney test and Wilcoxon-w test. Results: The total number of patients requiring MDZ and the mean dose of MDZ required to achieve targeted sedation (RSS ≥2) was significantly less in DEX group compared to the placebo group (P < 0.001). Similarly, patient satisfaction score, heart rate, systolic, diastolic and mean arterial pressure and respiratory parameters were significantly better in DEX group (P < 0.001). Postintubation arousability in the two groups was comparable (P = 0.29). Conclusions: Dexmedetomidine provides optimum sedation without compromising airway or hemodynamic instability with better patient tolerance and satisfaction for AFOI. It also preserves patient arousability for the postintubation neurological assessment. PMID:27006542

  5. Encoding Odorant Identity by Spiking Packets of Rate-Invariant Neurons in Awake Mice

    PubMed Central

    Gschwend, Olivier; Beroud, Jonathan; Carleton, Alan

    2012-01-01

    Background How do neural networks encode sensory information? Following sensory stimulation, neural coding is commonly assumed to be based on neurons changing their firing rate. In contrast, both theoretical works and experiments in several sensory systems showed that neurons could encode information as coordinated cell assemblies by adjusting their spike timing and without changing their firing rate. Nevertheless, in the olfactory system, there is little experimental evidence supporting such model. Methodology/Principal Findings To study these issues, we implanted tetrodes in the olfactory bulb of awake mice to record the odorant-evoked activity of mitral/tufted (M/T) cells. We showed that following odorant presentation, most M/T neurons do not significantly change their firing rate over a breathing cycle but rather respond to odorant stimulation by redistributing their firing activity within respiratory cycles. In addition, we showed that sensory information can be encoded by cell assemblies composed of such neurons, thus supporting the idea that coordinated populations of globally rate-invariant neurons could be efficiently used to convey information about the odorant identity. We showed that different coding schemes can convey high amount of odorant information for specific read-out time window. Finally we showed that the optimal readout time window corresponds to the duration of gamma oscillations cycles. Conclusion We propose that odorant can be encoded by population of cells that exhibit fine temporal tuning of spiking activity while displaying weak or no firing rate change. These cell assemblies may transfer sensory information in spiking packets sequence using the gamma oscillations as a clock. This would allow the system to reach a tradeoff between rapid and accurate odorant discrimination. PMID:22272291

  6. Negative Expiratory Pressure Technique: An Awake Test to Measure Upper Airway Collapsibility in Adolescents

    PubMed Central

    Carrera, Helena Larramona; Marcus, Carole L.; McDonough, Joseph M.; Morera, Joan C. Oliva; Huang, Jingtao; Farre, Ramon; Montserrat, Josep M.

    2015-01-01

    Study Objectives: Upper airway (UA) collapsibility is a major pathophysiologic feature of the obstructive sleep apnea syndrome (OSAS). In adolescents, it is measured by obtaining the slope of pressure-flow relationship (SPF) while applying negative nasal pressure during sleep. An easier technique to assess UA collapsibility, consisting of application of negative expiratory pressure (NEP) during wakefulness, has demonstrated differences between control and OSAS subjects. We hypothesized that the NEP technique would correlate with SPF as a measurement of UA collapsibility in adolescents. Design: During wakefulness, NEP of −5 cm H2O in the seated and supine position was applied during the first second of expiration. The area under the expiratory flow-volume curve during NEP was compared to tidal breathing (RatioNEP). In addition, adolescents underwent SPF measurements during sleep. Two SPF techniques were performed to measure the activated and relatively hypotonic UA. Setting: Pediatric sleep laboratory. Participants: Seven adolescents with OSAS and 20 controls. Results: In the seated position, there was a correlation between RatioNEP and both hypotonic SPF (r = −0.39, P = 0.04) and activated SPF (r = −0.62, P = 0.001). In the supine position, there was a correlation between RatioNEP and activated SPF (r = −0.43, P = 0.03) and a trend for hypotonic SPF (r = −0.38, P = 0.06). Conclusions: The negative expiratory pressure (NEP) technique correlates with the hypotonic and activated slope of pressure-flow relationship measurements. The seated position showed the strongest correlation. The NEP technique can be used as an alternative method to evaluate upper airway collapsibility in adolescents. Citation: Carrera HL, Marcus CL, McDonough JM, Morera JC, Huang J, Farre R, Montserrat JM. Negative expiratory pressure technique: an awake test to measure upper airway collapsibility in adolescents. SLEEP 2015;38(11):1783–1791. PMID:26158888

  7. Neuronal generators of the visual evoked potentials: intracerebral recording in awake humans.

    PubMed

    Ducati, A; Fava, E; Motti, E D

    1988-01-01

    Flash and pattern reversal visual evoked potentials were recorded in awake patients undergoing stereotactic procedures for severe dyskinetic disorders resistant to medical treatment. The nucleus ventralis lateralis thalami was reached via an occipital approach. VEPs were recorded on the scalp at the entrance of the intracerebral electrode, and serially from sites at different depths. A polarity reversal of the surface recorded wave form took place as the intracerebral electrode was advanced beneath the surface cortical layers. As concerns F-VEPs, most of the scalp activity mirrored the potentials recorded down to the depth of 70-65 mm from the thalamus. The largest amplitude of intracerebral F-VEPs was obtained from recording sites at 50-70 mm from the thalamus, i.e., in the depth of the calcarine fissure. A negative wave, peaking around 47-50 msec, became evident in recording sites at 30-40 mm from the thalamus but vanished as the electrode was advanced farther. In only one patient could we record a small negative wave, peaking at 33 msec, in the vicinity of the corpus geniculatum externum. Furthermore, the oscillatory activity recorded from the scalp appeared to be generated in the cortical layers. PR-VEPs also underwent polarity reversal as the electrode traversed the cortex. PR-VEPs disappeared more superficially than F-VEPs. No PR-evoked activity could be recorded in the vicinity of the corpus geniculatum externum. We conclude that slow and fast components of VEPs recorded from the scalp are entirely generated in cortical layers.

  8. Directional responses of visual wulst neurones to grating and plaid patterns in the awake owl.

    PubMed

    Baron, Jerome; Pinto, Lucas; Dias, Marcelo Oliveira; Lima, Bruss; Neuenschwander, Sergio

    2007-10-01

    The avian retinothalamofugal pathway reaches the telencephalon in an area known as visual wulst. A close functional analogy between this area and the early visual cortex of mammals has been established in owls. The goal of the present study was to assess quantitatively the directional selectivity and motion integration capability of visual wulst neurones, aspects that have not been previously investigated. We recorded extracellularly from a total of 101 cells in awake burrowing owls. From this sample, 88% of the units exhibited modulated directional responses to sinusoidal gratings, with a mean direction index of 0.74 +/- 0.03 and tuning bandwidth of 28 +/- 1.16 degrees . A direction index higher than 0.5 was observed in 66% of the cells, thereby qualifying them as direction selective. Motion integration was tested with moving plaids, made by adding two sinusoidal gratings of different orientations. We found that 80% of direction-selective cells responded optimally to the motion direction of the component gratings, whereas none responded to the global motion of plaids, whose direction was intermediate to that of the gratings. The remaining 20% were unclassifiable. The strength of component motion selectivity rapidly increased over a 200 ms period following stimulus onset, maintaining a relatively sustained profile thereafter. Overall, our data suggest that, as in the mammalian primary visual cortex, the visual wulst neurones of owls signal the local orientated features of a moving object. How and where these potentially ambiguous signals are integrated in the owl brain might be important for understanding the mechanisms underlying global motion perception. PMID:17897399

  9. Fast transmission from the dopaminergic ventral midbrain to the sensory cortex of awake primates.

    PubMed

    Mylius, Judith; Happel, Max F K; Gorkin, Alexander G; Huang, Ying; Scheich, Henning; Brosch, Michael

    2015-11-01

    Motivated by the increasing evidence that auditory cortex is under control of dopaminergic cell structures of the ventral midbrain, we studied how the ventral tegmental area and substantia nigra affect neuronal activity in auditory cortex. We electrically stimulated 567 deep brain sites in total within and in the vicinity of the two dopaminergic ventral midbrain structures and at the same time, recorded local field potentials and neuronal discharges in cortex. In experiments conducted on three awake macaque monkeys, we found that electrical stimulation of the dopaminergic ventral midbrain resulted in short-latency (~35 ms) phasic activations in all cortical layers of auditory cortex. We were also able to demonstrate similar activations in secondary somatosensory cortex and superior temporal polysensory cortex. The electrically evoked responses in these parts of sensory cortex were similar to those previously described for prefrontal cortex. Moreover, these phasic responses could be reversibly altered by the dopamine D1-receptor antagonist SCH23390 for several tens of minutes. Thus, we speculate that the dopaminergic ventral midbrain exerts a temporally precise, phasic influence on sensory cortex using fast-acting non-dopaminergic transmitters and that their effects are modulated by dopamine on a longer timescale. Our findings suggest that some of the information carried by the neuronal discharges in the dopaminergic ventral midbrain, such as the motivational value or the motivational salience, is transmitted to auditory cortex and other parts of sensory cortex. The mesocortical pathway may thus contribute to the representation of non-auditory events in the auditory cortex and to its associative functions. PMID:25084746

  10. Dopamine microinjected into brainstem of awake rats affects baseline arterial pressure but not chemoreflex responses.

    PubMed

    Oliva, Waldyr M; Granjeiro, Erica M; Bongamba, Leni G H; Mendes, Ricardo A; Machado, Benedito H

    2010-06-24

    Dopamine (DA) is a neuromodulator in the brainstem involved with the generation and modulation of the autonomic and respiratory activities. Here we evaluated the effect of microinjection of DA intracisterna magna (icm) or into the caudal nucleus tractus solitarii (cNTS) on the baseline cardiovascular and respiratory parameters and on the cardiovascular and respiratory responses to chemoreflex activation in awake rats. Guide cannulas were implanted in cisterna magna or cNTS and femoral artery and vein were catheterized. Respiratory frequency (f(R)) was measured by whole-body plethysmography. Chemoreflex was activated with KCN (iv) before and after microinjection of DA icm or into the cNTS bilaterally while mean arterial pressure (MAP), heart rate (HR) and f(R) were recorded. Microinjection of DA icm (n=13), but not into the cNTS (n=8) produced a significant decrease in baseline MAP (-15+/-1 vs 1+/-1mmHg) and HR (-55+/-11 vs -11+/-17bpm) in relation to control (saline with ascorbic acid, n=9) but no significant changes in baseline f(R). Microinjection of DA icm or into the cNTS produced no significant changes in the pressor, bradycardic and tachypneic responses to chemoreflex activation. These data show that a) DA icm affects baseline cardiovascular regulation, but not baseline f(R) and autonomic and respiratory components of chemoreflex and b) DA into the cNTS does not affect either the autonomic activity to the cardiovascular system or the autonomic and respiratory responses of chemoreflex activation.

  11. Neuropeptides in the posterodorsal medial amygdala modulate central cardiovascular reflex responses in awake male rats

    PubMed Central

    Quagliotto, E.; Casali, K.R.; Dal Lago, P.; Rasia-Filho, A.A.

    2014-01-01

    The rat posterodorsal medial amygdala (MePD) links emotionally charged sensory stimuli to social behavior, and is part of the supramedullary control of the cardiovascular system. We studied the effects of microinjections of neuroactive peptides markedly found in the MePD, namely oxytocin (OT, 10 ng and 25 pg; n=6/group), somatostatin (SST, 1 and 0.05 μM; n=8 and 5, respectively), and angiotensin II (Ang II, 50 pmol and 50 fmol; n=7/group), on basal cardiovascular activity and on baroreflex- and chemoreflex-mediated responses in awake adult male rats. Power spectral and symbolic analyses were applied to pulse interval and systolic arterial pressure series to identify centrally mediated sympathetic/parasympathetic components in the heart rate variability (HRV) and arterial pressure variability (APV). No microinjected substance affected basal parameters. On the other hand, compared with the control data (saline, 0.3 µL; n=7), OT (10 ng) decreased mean AP (MAP50) after baroreflex stimulation and increased both the mean AP response after chemoreflex activation and the high-frequency component of the HRV. OT (25 pg) increased overall HRV but did not affect any parameter of the symbolic analysis. SST (1 μM) decreased MAP50, and SST (0.05 μM) enhanced the sympathovagal cardiac index. Both doses of SST increased HRV and its low-frequency component. Ang II (50 pmol) increased HRV and reduced the two unlike variations pattern of the symbolic analysis (P<0.05 in all cases). These results demonstrate neuropeptidergic actions in the MePD for both the increase in the range of the cardiovascular reflex responses and the involvement of the central sympathetic and parasympathetic systems on HRV and APV. PMID:25424367

  12. Stimulation of the cardiopulmonary baroreflex enhances ventricular contractility in awake dogs: a mathematical analysis study.

    PubMed

    Sala-Mercado, Javier A; Moslehpour, Mohsen; Hammond, Robert L; Ichinose, Masashi; Chen, Xiaoxiao; Evan, Sell; O'Leary, Donal S; Mukkamala, Ramakrishna

    2014-08-15

    The cardiopulmonary baroreflex responds to an increase in central venous pressure (CVP) by decreasing total peripheral resistance and increasing heart rate (HR) in dogs. However, the direction of ventricular contractility change is not well understood. The aim was to elucidate the cardiopulmonary baroreflex control of ventricular contractility during normal physiological conditions via a mathematical analysis. Spontaneous beat-to-beat fluctuations in maximal ventricular elastance (Emax), which is perhaps the best available index of ventricular contractility, CVP, arterial blood pressure (ABP), and HR were measured from awake dogs at rest before and after β-adrenergic receptor blockade. An autoregressive exogenous input model was employed to jointly identify the three causal transfer functions relating beat-to-beat fluctuations in CVP to Emax (CVP → Emax), which characterizes the cardiopulmonary baroreflex control of ventricular contractility, ABP to Emax, which characterizes the arterial baroreflex control of ventricular contractility, and HR to Emax, which characterizes the force-frequency relation. The CVP → Emax transfer function showed a static gain of 0.037 ± 0.010 ml(-1) (different from zero; P < 0.05) and an overall time constant of 3.2 ± 1.2 s. Hence, Emax would increase and reach steady state in ∼16 s in response to a step increase in CVP, without any change to ABP or HR, due to the cardiopulmonary baroreflex. Following β-adrenergic receptor blockade, the CVP → Emax transfer function showed a static gain of 0.0007 ± 0.0113 ml(-1) (different from control; P < 0.10). Hence, Emax would change little in steady state in response to a step increase in CVP. Stimulation of the cardiopulmonary baroreflex increases ventricular contractility through β-adrenergic receptor system mediation.

  13. Fast transmission from the dopaminergic ventral midbrain to the sensory cortex of awake primates.

    PubMed

    Mylius, Judith; Happel, Max F K; Gorkin, Alexander G; Huang, Ying; Scheich, Henning; Brosch, Michael

    2015-11-01

    Motivated by the increasing evidence that auditory cortex is under control of dopaminergic cell structures of the ventral midbrain, we studied how the ventral tegmental area and substantia nigra affect neuronal activity in auditory cortex. We electrically stimulated 567 deep brain sites in total within and in the vicinity of the two dopaminergic ventral midbrain structures and at the same time, recorded local field potentials and neuronal discharges in cortex. In experiments conducted on three awake macaque monkeys, we found that electrical stimulation of the dopaminergic ventral midbrain resulted in short-latency (~35 ms) phasic activations in all cortical layers of auditory cortex. We were also able to demonstrate similar activations in secondary somatosensory cortex and superior temporal polysensory cortex. The electrically evoked responses in these parts of sensory cortex were similar to those previously described for prefrontal cortex. Moreover, these phasic responses could be reversibly altered by the dopamine D1-receptor antagonist SCH23390 for several tens of minutes. Thus, we speculate that the dopaminergic ventral midbrain exerts a temporally precise, phasic influence on sensory cortex using fast-acting non-dopaminergic transmitters and that their effects are modulated by dopamine on a longer timescale. Our findings suggest that some of the information carried by the neuronal discharges in the dopaminergic ventral midbrain, such as the motivational value or the motivational salience, is transmitted to auditory cortex and other parts of sensory cortex. The mesocortical pathway may thus contribute to the representation of non-auditory events in the auditory cortex and to its associative functions.

  14. Effect of superfused insulin on cerebral cortical glucose utilization in awake goats

    SciTech Connect

    Pelligrino, D.A.; Miletich, D.J.; Albrecht, R.F. )

    1987-10-01

    The effect on cortical cerebral glucose utilization (CMR{sub glu}) of intracerebral insulin administration in awake goats was studied. The insulin was superfused in a mock cerebrospinal fluid (CSF) employing chronically implanted cranial windows. Two windows were implanted bilaterally: one window over an equivalent portion of each parietal cortex. With one window used to deliver insulin/CSF and the other used to simultaneously deliver CSF alone (control), changes in CMR{sub glu} were assessed using a modification of a sequential 2-({sup 3}H)- then 2({sup 14}C)deoxy-D-glucose (2DG) technique originally described by Altenau and Agranoff. Initial experiments employing {sup 125}I-insulin demonstrated that the superfusion procedure increased insulin levels only in the outer 1 mm of cortical tissue exposed to insulin containing perfusate. Additional preliminary evaluations, using conditions known to alter CMR{sub glu}, generally established that present methods were adequate to induce and detect CMR{sub glu} changes. However, it was also shown experimentally and using a mathematical model that 2-({sup 3}H)DG test/control tissue ratios could be influenced by subsequent changes in CMR{sub glu} and the dephosphorylation rate. Thus {sup 3}H ratios could not be used to establish preexperimental test/control CMR{sub glu} relationships as the originally devised model assumed but could be employed to indicate changes in dephosphorylation. The mathematical model allowed for improved estimates of CMR{sub glu} changes from 2({sup 14}C)DG/2-({sup 3}H)DG test over control tissue ratios. Even with these corrections, insulin was estimated to cause no more than an 8-15% increase in cortical CMR{sub glu}. A very limited role for insulin, at least in cerebral cortical metabolic regulation, is thus indicated.

  15. The BEHAVE-AD Assessment System: A Perspective, A Commentary on New Findings, and A Historical Review

    PubMed Central

    Reisberg, Barry; Monteiro, Isabel; Torossian, Carol; Auer, Stefanie; Shulman, Melanie B.; Ghimire, Santosh; Boksay, Istvan; BenArous, Francoise Guillo; Osorio, Ricardo; Vengassery, Aninditha; Imran, Sheema; Shaker, Hussam; Noor, Sadaf; Naqvi, Shazia; Kenowsky, Sunnie; Xu, Jinfeng

    2014-01-01

    Background Behavioral and psychological symptoms of dementia (BPSD) and associated disturbances in Alzheimer's disease (AD) are a source of distress and burden for spouses, professional caregivers, and others with responsibilities for the care of individuals with AD. BPSD with behavioral disturbances are also associated with more rapid institutionalization and increased morbidity and mortality for persons with AD. Objectives In this review and commentary, we discuss the history of the development of BPSD and behavioral disturbance assessments, which are distinct from those evaluating cognitive and functional symptoms of AD. In particular, we review the informant-based Behavioral Pathology in Alzheimer's Disease Rating Scale (BEHAVE-AD), the related, potentially more sensitive, BEHAVE-AD Frequency-Weighted Severity Scale (BEHAVE-AD-FW), and the direct subject evaluation-based Empirical BEHAVE-AD Rating Scale (E-BEHAVE-AD). The kinds of medications that alleviate behavioral symptoms on these measures as well as the problems and possibilities for further advances with these medications are discussed. Finally, the importance of distinguishing BPSD and behavioral disturbance remediation in AD from the treatment of cognitive decline and other aspects of AD is emphasized in the context of appropriate assessment methodology. The objective of this paper is to provide a framework for further advances in the treatment of BPSD and associated behavioral disturbances in AD and, consequently, a framework for continuing improvements in the lives of individuals with AD and those who share the burden of the disease with the AD person. PMID:24714384

  16. Extrinsic tongue and suprahyoid muscle activities during mastication in freely feeding rabbits.

    PubMed

    Inoue, Makoto; Ariyasinghe, Sajjiv; Yamamura, Kensuke; Harasawa, Yohji; Yamada, Yoshiaki

    2004-09-24

    To evaluate the coordination of tongue and suprahyoid muscle activities during natural mastication, electromyograms (EMGs) of jaw-closer, jaw-opener, suprahyoid (mylohyoid, MH), tongue-retractor (styloglossus, SG) and tongue-protractor (genioglossus, GG) muscles were recorded as well as the jaw-movement trajectories in vertical and horizontal axes in awake rabbits. Each masticatory cycle had three components including the fast-closing (FC), slow-closing (SC) and opening (Op) phases. The duration of the SC phase was much longer during pellet chewing while the durations of the FC and Op phases were much shorter during pellet chewing than bread or banana chewing. The jaw movements during banana chewing had a small amplitude of lateral excursion and a large amplitude of gape as compared with those during pellet and bread chewing. The MH muscle exhibited double-peaked EMG bursts during the Op phase. The MH bursts in the late part of the Op phase were dominant on the non-chewing side during pellet and bread chewing. The SG muscle also exhibited double-peaked EMG bursts. During pellet and bread chewing, the SG bursts during the SC phase were significantly larger on the chewing side than the non-chewing side. These bursts were also dominant during pellet chewing as compared with banana chewing. There was little difference in the GG bursts between the chewing and non-chewing sides or among the foods. Our results suggest that patterns of the MH and SG muscle activity are affected by the peripheral inputs and/or chewing patterns while those of the GG muscle activity was less modulated regardless of the consistency of foods.

  17. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla

    PubMed Central

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H.; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1–3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1–6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla

  18. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

    PubMed

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea.

  19. Comparison between human awake, meditation and drowsiness EEG activities based on directed transfer function and MVDR coherence methods.

    PubMed

    Dissanayaka, Chamila; Ben-Simon, Eti; Gruberger, Michal; Maron-Katz, Adi; Sharon, Haggai; Hendler, Talma; Cvetkovic, Dean

    2015-07-01

    This study examined the electroencephalogram functional connectivity (coherence) and effective connectivity (flow of information) of selected brain regions during three different attentive states: awake, meditation and drowsiness. For the estimation of functional connectivity (coherence), Welch and minimum variance distortionless response (MVDR) methods were compared. The MVDR coherence was found to be more suitable since it is both data and frequency dependent and enables higher spectral resolution, while Welch's periodogram-based approach is both data and frequency independent. The directed transfer function (DTF) method was applied in order to estimate the effective connectivity or brain's flow of information between different regions during each state. DTF enables to identify the main brain areas that initiate EEG activity and the spatial distribution of these activities with time. Analysis was conducted using the EEG data of 30 subjects (ten awake, ten drowsy and ten meditating) focusing on six main electrodes (F3, F4, C3, C4, P3, P4, O1 and O2). For each subject, EEG data were recorded during 5-min baseline and 15 min of a specific condition (awake, meditation or drowsiness). Statistical analysis included the Kruskal-Wallis (KW) nonparametric analysis of variance followed by post hoc tests with Bonferroni alpha correction. The results reveal that both states of drowsiness and meditation states lead to a marked difference in the brain's flow of information (effective connectivity) as shown by DTF analyses. In specific, a significant increase in the flow of information in the delta frequency band was found only in the meditation condition and was further found to originate from frontal (F3, F4), parietal (P3, P4) and occipital (O1, O2) regions. Altogether, these results suggest that a change in attentiveness leads to significant changes in the spectral profile of the brain's information flow as well as in its functional connectivity and that these changes can

  20. A comparison of dexmedetomidine plus ketamine combination with dexmedetomidine alone for awake fiberoptic nasotracheal intubation: A randomized controlled study

    PubMed Central

    Sinha, Sunil Kumar; Joshiraj, Bandi; Chaudhary, Lalita; Hayaran, Nitin; Kaur, Manpreet; Jain, Aruna

    2014-01-01

    Background and Aims: We designed a study to compare the effectiveness of dexmedetomidine plus ketamine combination with dexmedetomidine alone in search of an ideal sedation regime, which would achieve better intubating conditions, hemodynamic stability, and sedation for awake fiberoptic nasotracheal intubation. Materials and Methods: A total of 60 adult patients of age group 18-60 years with American Society of Anesthesiologists I and II posted for elective surgery under general anesthesia were randomly divided into two groups of 30 each in this prospective randomized controlled double-blinded study. Groups I and II patients received a bolus dose of dexmedetomidine at 1 mcg/kg over 10 min followed by a continuous infusion of dexmedetomidine at 0.5 mcg/kg/h. Upon completion of the dexmedetomidine bolus, Group I patients received 15 mg of ketamine and an infusion of ketamine at 20 mg/h followed by awake fiberoptic nasotracheal intubation, while Group II patients upon completion of dexmedetomidine bolus received plain normal saline instead of ketamine. Hemodynamic variables like heart rate (HR) and mean arterial pressure (MAP), oxygen saturation, electrocardiogram changes, sedation score (modified Observer assessment of alertness/sedation score), intubation score (vocal cord movement and coughing), grimace score, time taken for intubation, amount of lignocaine used were noted during the course of study. Patient satisfaction score and level of recall were assessed during the postoperative visit the next day. Results: Group I patients maintained a stable HR and MAP (<10% fall when compared with the baseline value). Sedation score (3.47 vs. 3.93) and patient satisfaction score were better in Group I patients. There was no significant difference in intubation scores, grimace scores, oxygen saturation and level of recall when compared between the two groups (P > 0.05). Conclusion: The use of dexmedetomidine plus ketamine combination in awake fiberoptic nasotracheal

  1. Stronger efferent suppression of cochlear neural potentials by contralateral acoustic stimulation in awake than in anesthetized chinchilla.

    PubMed

    Aedo, Cristian; Tapia, Eduardo; Pavez, Elizabeth; Elgueda, Diego; Delano, Paul H; Robles, Luis

    2015-01-01

    There are two types of sensory cells in the mammalian cochlea, inner hair cells, which make synaptic contact with auditory-nerve afferent fibers, and outer hair cells that are innervated by crossed and uncrossed medial olivocochlear (MOC) efferent fibers. Contralateral acoustic stimulation activates the uncrossed efferent MOC fibers reducing cochlear neural responses, thus modifying the input to the central auditory system. The chinchilla, among all studied mammals, displays the lowest percentage of uncrossed MOC fibers raising questions about the strength and frequency distribution of the contralateral-sound effect in this species. On the other hand, MOC effects on cochlear sensitivity have been mainly studied in anesthetized animals and since the MOC-neuron activity depends on the level of anesthesia, it is important to assess the influence of anesthesia in the strength of efferent effects. Seven adult chinchillas (Chinchilla laniger) were chronically implanted with round-window electrodes in both cochleae. We compared the effect of contralateral sound in awake and anesthetized condition. Compound action potentials (CAP) and cochlear microphonics (CM) were measured in the ipsilateral cochlea in response to tones in absence and presence of contralateral sound. Control measurements performed after middle-ear muscles section in one animal discarded any possible middle-ear reflex activation. Contralateral sound produced CAP amplitude reductions in all chinchillas, with suppression effects greater by about 1-3 dB in awake than in anesthetized animals. In contrast, CM amplitude increases of up to 1.9 dB were found in only three awake chinchillas. In both conditions the strongest efferent effects were produced by contralateral tones at frequencies equal or close to those of ipsilateral tones. Contralateral CAP suppressions for 1-6 kHz ipsilateral tones corresponded to a span of uncrossed MOC fiber innervation reaching at least the central third of the chinchilla cochlea

  2. A Valuable and Promising Method for Recording Brain Activity in Behaving Newborn Rodents

    PubMed Central

    Sokoloff, Greta; Tiriac, Alexandre; Del Rio-Bermudez, Carlos

    2015-01-01

    Neurophysiological recording of brain activity has been critically important to the field of neuroscience, but has contributed little to the field of developmental psychobiology. The reasons for this can be traced largely to methodological difficulties associated with recording neural activity in behaving newborn rats and mice. Over the last decade, however, the evolution of methods for recording from head-fixed newborns has heralded a new era in developmental neurophysiology. Here, we review these recent developments and provide a step-by-step primer for those interested in applying the head-fix method to their own research questions. Until now, this method has been used primarily to investigate spontaneous brain activity across sleep and wakefulness, the contributions of the sensory periphery to brain activity, or intrinsic network activity. Now, with some ingenuity, the uses of the head-fix method can be expanded to other domains to benefit our understanding of brain-behavior relations under normal and pathophysiological conditions across early development. PMID:25864710

  3. Quantum-behaved particle swarm optimization: analysis of individual particle behavior and parameter selection.

    PubMed

    Sun, Jun; Fang, Wei; Wu, Xiaojun; Palade, Vasile; Xu, Wenbo

    2012-01-01

    Quantum-behaved particle swarm optimization (QPSO), motivated by concepts from quantum mechanics and particle swarm optimization (PSO), is a probabilistic optimization algorithm belonging to the bare-bones PSO family. Although it has been shown to perform well in finding the optimal solutions for many optimization problems, there has so far been little analysis on how it works in detail. This paper presents a comprehensive analysis of the QPSO algorithm. In the theoretical analysis, we analyze the behavior of a single particle in QPSO in terms of probability measure. Since the particle's behavior is influenced by the contraction-expansion (CE) coefficient, which is the most important parameter of the algorithm, the goal of the theoretical analysis is to find out the upper bound of the CE coefficient, within which the value of the CE coefficient selected can guarantee the convergence or boundedness of the particle's position. In the experimental analysis, the theoretical results are first validated by stochastic simulations for the particle's behavior. Then, based on the derived upper bound of the CE coefficient, we perform empirical studies on a suite of well-known benchmark functions to show how to control and select the value of the CE coefficient, in order to obtain generally good algorithmic performance in real world applications. Finally, a further performance comparison between QPSO and other variants of PSO on the benchmarks is made to show the efficiency of the QPSO algorithm with the proposed parameter control and selection methods.

  4. How Do Children Behave Regarding Their Birth Order in Dental Setting?

    PubMed Central

    Ghaderi, Faezeh; Fijan, Soleiman; Hamedani, Shahram

    2015-01-01

    Statement of the Problem Prediction of child cooperation level in dental setting is an important issue for a dentist to select the proper behavior management method. Many psychological studies have emphasized the effect of birth order on patient behavior and personality; however, only a few researches evaluated the effect of birth order on child’s behavior in dental setting. Purpose This study was designed to evaluate the influence of children ordinal position on their behavior in dental setting. Materials and Method A total of 158 children with at least one primary mandibular molar needing class I restoration were selected. Children were classified based on the ordinal position; first, middle, or last child as well as single child. A blinded examiner recorded the pain perception of children during injection based on Visual Analogue Scale (VAS) and Sound, Eye and Movement (SEM) scale. To assess the child's anxiety, the questionnaire known as “Dental Subscale of the Children's Fear Survey Schedule” (CFSS-DS) was employed. Results The results showed that single children were significantly less cooperative and more anxious than the other children (p<0.001). The middle children were significantly more cooperative in comparison with the other child's position (p< 0.001). Conclusion Single child may behave less cooperatively in dental setting. The order of child birth must also be considered in prediction of child’s behavior for behavioral management. PMID:26636121

  5. Social class, power, and selfishness: when and why upper and lower class individuals behave unethically.

    PubMed

    Dubois, David; Rucker, Derek D; Galinsky, Adam D

    2015-03-01

    Are the rich more unethical than the poor? To answer this question, the current research introduces a key conceptual distinction between selfish and unethical behavior. Based on this distinction, the current article offers 2 novel findings that illuminate the relationship between social class and unethical behavior. First, the effects of social class on unethical behavior are not invariant; rather, the effects of social class are moderated by whether unethical behavior benefits the self or others. Replicating past work, social class positively predicted unethical behavior; however, this relationship was only observed when that behavior was self-beneficial. When unethical behavior was performed to benefit others, social class negatively predicted unethical behavior; lower class individuals were more likely than upper class individuals to engage in unethical behavior. Overall, social class predicts people's tendency to behave selfishly, rather than predicting unethical behavior per se. Second, individuals' sense of power drove the effects of social class on unethical behavior. Evidence for this relationship was provided in three forms. First, income, but not education level, predicted unethical behavior. Second, feelings of power mediated the effect of social class on unethical behavior, but feelings of status did not. Third, two distinct manipulations of power produced the same moderation by self-versus-other beneficiary as was found with social class. The current theoretical framework and data both synthesize and help to explain a range of findings in the social class and power literatures.

  6. The embodiment of tourism among bisexually-behaving Dominican male sex workers.

    PubMed

    Padilla, Mark B

    2008-10-01

    While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality.

  7. A functional architecture of optic flow in the inferior parietal lobule of the behaving monkey.

    PubMed

    Raffi, Milena; Siegel, Ralph M

    2007-02-07

    The representation of navigational optic flow across the inferior parietal lobule was assessed using optical imaging of intrinsic signals in behaving monkeys. The exposed cortex, corresponding to the dorsal-most portion of areas 7a and dorsal prelunate (DP), was imaged in two hemispheres of two rhesus monkeys. The monkeys actively attended to changes in motion stimuli while fixating. Radial expansion and contraction, and rotation clockwise and counter-clockwise optic flow stimuli were presented concentric to the fixation point at two angles of gaze to assess the interrelationship between the eye position and optic flow signal. The cortical response depended upon the type of flow and was modulated by eye position. The optic flow selectivity was embedded in a patchy architecture within the gain field architecture. All four optic flow stimuli tested were represented in areas 7a and DP. The location of the patches varied across days. However the spatial periodicity of the patches remained constant across days at approximately 950 and 1100 microm for the two animals examined. These optical recordings agree with previous electrophysiological studies of area 7a, and provide new evidence for flow selectivity in DP and a fine scale description of its cortical topography. That the functional architectures for optic flow can change over time was unexpected. These and earlier results also from inferior parietal lobule support the inclusion of both static and dynamic functional architectures that define association cortical areas and ultimately support complex cognitive function.

  8. Functional architecture of retinotopy in visual association cortex of behaving monkey.

    PubMed

    Heider, Barbara; Jandó, Gábor; Siegel, Ralph M

    2005-04-01

    While the receptive field properties of single neurons in the inferior parietal cortex have been quantitatively described from numerous electrical measurements, the visual topography of area 7a and the adjacent dorsal prelunate area (DP) remains unknown. This lacuna may be a technical byproduct of the difficulty of reconstructing tens to hundreds of penetrations, or may be the result of varying functional retinotopic architectures. Intrinsic optical imaging, performed in behaving monkey for extended periods of time, was used to evaluate retinotopy simultaneously at multiple positions across the cortical surface. As electrical recordings through an implanted artificial dura are difficult, the measurement and quantification of retinotopy with long-term recordings was validated by imaging early visual cortex (areas V1 and V2). Retinotopic topography was found in each of the three other areas studied within a single day's experiment. However, the ventral portion of DP (DPv) had a retinotopic topography that varied from day to day, while the more dorsal aspects (DPd) exhibited consistent retinotopy. This suggests that the dorsal prelunate gyrus may consist of more than one visual area. The retinotopy of area 7a also varied from day to day. Possible mechanisms for this variability across days are discussed as well as its impact upon our understanding of the representation of extrapersonal space in the inferior parietal cortex.

  9. The conceptual underpinnings of pretense: pretending is not 'behaving-as-if'.

    PubMed

    Friedman, Ori; Leslie, Alan M

    2007-10-01

    The ability to engage in and recognize pretend play begins around 18 months. A major challenge for theories of pretense is explaining how children are able to engage in pretense, and how they are able to recognize pretense in others. According to one major account, the metarepresentational theory, young children possess both production and recognition abilities because they possess the mental state concept, pretend. According to a more recent rival account, the Behavioral theory, young children are behaviorists about pretense, and only produce and recognize pretense as a sort of behavior - namely, behaving 'as-if'. We review both the metarepresentational and Behavioral accounts and argue that the Behavioral theory fails to characterize very young children's abilities to produce and to recognize pretense. Among other problems, the Behavioral theory implies that children should frequently mis-recognize regular behavior as pretense, while certain regular forms of pretend play should neither be produced nor recognized. Like other mental states, pretense eludes purely behavioral description. The metarepresentational theory does not suffer these problems and provides a better account of children's pretense.

  10. A Functional Architecture of Optic Flow in the Inferior Parietal Lobule of the Behaving Monkey

    PubMed Central

    Raffi, Milena; Siegel, Ralph M.

    2007-01-01

    The representation of navigational optic flow across the inferior parietal lobule was assessed using optical imaging of intrinsic signals in behaving monkeys. The exposed cortex, corresponding to the dorsal-most portion of areas 7a and dorsal prelunate (DP), was imaged in two hemispheres of two rhesus monkeys. The monkeys actively attended to changes in motion stimuli while fixating. Radial expansion and contraction, and rotation clockwise and counter-clockwise optic flow stimuli were presented concentric to the fixation point at two angles of gaze to assess the interrelationship between the eye position and optic flow signal. The cortical response depended upon the type of flow and was modulated by eye position. The optic flow selectivity was embedded in a patchy architecture within the gain field architecture. All four optic flow stimuli tested were represented in areas 7a and DP. The location of the patches varied across days. However the spatial periodicity of the patches remained constant across days at ∼950 and 1100 µm for the two animals examined. These optical recordings agree with previous electrophysiological studies of area 7a, and provide new evidence for flow selectivity in DP and a fine scale description of its cortical topography. That the functional architectures for optic flow can change over time was unexpected. These and earlier results also from inferior parietal lobule support the inclusion of both static and dynamic functional architectures that define association cortical areas and ultimately support complex cognitive function. PMID:17285147

  11. The embodiment of tourism among bisexually-behaving Dominican male sex workers.

    PubMed

    Padilla, Mark B

    2008-10-01

    While theories of "structure" and social inequality have increasingly informed global health efforts for HIV prevention--with growing recognition of the linkages between large-scale political and economic factors in the distribution and impact of the HIV/AIDS epidemic--there is still little theorization of precisely how structural factors shape the very bodies and sexualities of specific populations and groups. In order to extend the theoretical understanding of these macro-micro linkages, this article examines how the growth of the tourism industry in the Dominican Republic has produced sexual practices and identities that reflect both the influence of large-scale structural processes and the resistant responses of local individuals. Drawing on social science theories of political economy, embodiment, and authenticity, I argue that an understanding of patterns of sexuality and HIV risk in the region requires analysis of how political-economic transformations related to tourism intersect with the individual experiences and practices of sexuality on the ground. The analysis draws on long-term ethnographic research with bisexually behaving male sex workers in two cities in the Dominican Republic, including participant observation, in-depth interviews, focus groups, and surveys. By examining the global and local values placed on these men's bodies and the ways sex workers use their bodies to broker tourists' pleasure, we may better understand how the large-scale structures of the tourism industry are linked to the specific meanings and practices of sexuality. PMID:18506615

  12. Activity of Caudate Nucleus Neurons in a Visual Fixation Paradigm in Behaving Cats

    PubMed Central

    Nagypál, Tamás; Gombkötő, Péter; Barkóczi, Balázs; Benedek, György; Nagy, Attila

    2015-01-01

    Beside its motor functions, the caudate nucleus (CN), the main input structure of the basal ganglia, is also sensitive to various sensory modalities. The goal of the present study was to investigate the effects of visual stimulation on the CN by using a behaving, head-restrained, eye movement-controlled feline model developed recently for this purpose. Extracellular multielectrode recordings were made from the CN of two cats in a visual fixation paradigm applying static and dynamic stimuli. The recorded neurons were classified in three groups according to their electrophysiological properties: phasically active (PAN), tonically active (TAN) and high-firing (HFN) neurons. The response characteristics were investigated according to this classification. The PAN and TAN neurons were sensitive primarily to static stimuli, while the HFN neurons responded primarily to changes in the visual environment i.e. to optic flow and the offset of the stimuli. The HFNs were the most sensitive to visual stimulation; their responses were stronger than those of the PANs and TANs. The majority of the recorded units were insensitive to the direction of the optic flow, regardless of group, but a small number of direction-sensitive neurons were also found. Our results demonstrate that both the static and the dynamic components of the visual information are represented in the CN. Furthermore, these results provide the first piece of evidence on optic flow processing in the CN, which, in more general terms, indicates the possible role of this structure in dynamic visual information processing. PMID:26544604

  13. The neuropharmacology of upper airway motor control in the awake and asleep states: implications for obstructive sleep apnoea

    PubMed Central

    Horner, Richard L

    2001-01-01

    Obstructive sleep apnoea is a common and serious breathing problem that is caused by effects of sleep on pharyngeal muscle tone in individuals with narrow upper airways. There has been increasing focus on delineating the brain mechanisms that modulate pharyngeal muscle activity in the awake and asleep states in order to understand the pathogenesis of obstructive apnoeas and to develop novel neurochemical treatments. Although initial clinical studies have met with only limited success, it is proposed that more rational and realistic approaches may be devised for neurochemical modulation of pharyngeal muscle tone as the relevant neurotransmitters and receptors that are involved in sleep-dependent modulation are identified following basic experiments. PMID:11686898

  14. Effects of naloxone and naltrexone on meal patterns of freely-feeding rats.

    PubMed

    Kirkham, T C; Blundell, J E

    1987-03-01

    The effects of naloxone and naltrexone on the night-time meal patterning of freely-feeding male rats were investigated using a Kissileff-type eatometer. Naloxone (5.0 mg/kg) and naltrexone (2.5 mg/kg) reduced intake for two hours after IP injection. This effect resulted from a shortening of duration of meals and an extension of postmeal intervals. Unlike other anorexic agents neither drug affected meal frequency or the eating rate within meals. These particular opioid antagonists therefore appear to produce anorexia by advancing meal termination and extending the inhibition of feeding which follows a meal. These specific changes in the structure of the meal pattern consolidate previous findings and support the hypothesis that naloxone and naltrexone reduce food intake in rats by promoting satiation and prolonging satiety.

  15. Quantitative wake analysis of a freely swimming fish using 3D synthetic aperture PIV

    NASA Astrophysics Data System (ADS)

    Mendelson, Leah; Techet, Alexandra H.

    2015-07-01

    Synthetic aperture PIV (SAPIV) is used to quantitatively analyze the wake behind a giant danio ( Danio aequipinnatus) swimming freely in a seeded quiescent tank. The experiment is designed with minimal constraints on animal behavior to ensure that natural swimming occurs. The fish exhibits forward swimming and turning behaviors at speeds between 0.9 and 1.5 body lengths/second. Results show clearly isolated and linked vortex rings in the wake structure, as well as the thrust jet coming off of a visual hull reconstruction of the fish body. As a benchmark for quantitative analysis of volumetric PIV data, the vortex circulation and impulse are computed using methods consistent with those applied to planar PIV data. Volumetric momentum analysis frameworks are discussed for linked and asymmetric vortex structures, laying a foundation for further volumetric studies of swimming hydrodynamics with SAPIV. Additionally, a novel weighted refocusing method is presented as an improvement to SAPIV reconstruction.

  16. Picosecond supercontinuum light source for stroboscopic white-light interferometry with freely adjustable pulse repetition rate.

    PubMed

    Novotny, Steffen; Durairaj, Vasuki; Shavrin, Igor; Lipiäinen, Lauri; Kokkonen, Kimmo; Kaivola, Matti; Ludvigsen, Hanne

    2014-06-01

    We present a picosecond supercontinuum light source designed for stroboscopic white-light interferometry. This source offers a potential for high-resolution characterization of vibrational fields in electromechanical components with frequencies up to the GHz range. The light source concept combines a gain-switched laser diode, the output of which is amplified in a two-stage fiber amplifier, with supercontinuum generation in a microstructured optical fiber. Implemented in our white-light interferometer setup, optical pulses with optimized spectral properties and below 310 ps duration are used for stroboscopic illumination at freely adjustable repetition rates. The performance of the source is demonstrated by characterizing the surface vibration field of a square-plate silicon MEMS resonator at 3.37 MHz. A minimum detectable vibration amplitude of less than 100 pm is reached.

  17. Layer Thinning in Freely-Suspended Thin Liquid Films of a Symmetric Liquid Crystal Dimer

    NASA Astrophysics Data System (ADS)

    Pardaev, Shokir; Parsouzi, Zeinab; Gleeson, James; Jakli, Antal; Sprunt, Samuel

    We report optical reflectivity and dynamic light scattering (DLS) studies on freely suspended smectic films of a symmetric liquid crystal dimer, which exhibits the phase sequence isotropic--nematic--twist-bend nematic--smectic in cooling. In sufficiently thin films the reflectivity R is expected to scale as the square of the number of smectic layers (N2) while the frequency f of underdamped layer fluctuations scales as N - 1 / 2. On heating thin films drawn in the smectic phase, we observe a sequence of layer thinning transitions, with R and f following the expected scaling relations, provided the stepwise melting involves double rather than single layers. We will describe a model to explain the unusual layer thinning process. We thank M. G. Tamba and G. Mehl for providing the liquid crystal compound: NSF grant DMR-1307674.

  18. Enhanced glucose tolerance by intravascularly administered piceatannol in freely moving healthy rats.

    PubMed

    Oritani, Yukihiro; Okitsu, Teru; Nishimura, Eisaku; Sai, Masahiko; Ito, Tatsuhiko; Takeuchi, Shoji

    2016-02-12

    Piceatannol is a phytochemical in the seeds of passion fruit that has a hypoglycemic effect when orally administered. To elucidate the contribution of intact and metabolites of piceatannol after gastro-intestinal absorption to hypoglycemic effect, we examined the influence of piceatannol and isorhapontigenin on blood glucose concentrations during fasting and glucose tolerance tests by administering them intravascularly to freely moving healthy rats. We found that intravascularly administered piceatannol reduced the blood glucose concentrations during both fasting and glucose tolerance tests, but isorhapontigenin did not during either of them. Furthermore, we found that piceatannol increased the insulinogenic index during glucose tolerance tests and that piceatannol had no influence on insulin sensitivity by performing hyperinsulinemic euglycemic clamping tests. These results suggest that piceatannol orally intaken may enhance glucose tolerance by the effect of intact piceatannol through enhanced early-phase secretion of insulin. Therefore, oral intake of piceatannol might contribute to proper control of postprandial glycemic excursions in healthy subjects.

  19. Freely designable optical frequency conversion in Raman-resonant four-wave-mixing process

    PubMed Central

    Zheng, Jian; Katsuragawa, Masayuki

    2015-01-01

    Nonlinear optical processes are governed by the relative-phase relationships among the relevant electromagnetic fields in these processes. In this Report, we describe the physics of arbitrary manipulation of Raman-resonant four-wave-mixing process by artificial control of relative phases. As a typical example, we show freely designable optical-frequency conversions to extreme spectral regions, mid-infrared and vacuum-ultraviolet, with near-unity quantum efficiencies. Furthermore, we show that such optical-frequency conversions can be realized by using a surprisingly simple technology where transparent plates are placed in a nonlinear optical medium and their positions and thicknesses are adjusted precisely. In a numerical simulation assuming practically applicable parameters in detail, we demonstrate a single-frequency tunable laser that covers the whole vacuum-ultraviolet spectral range of 120 to 200 nm. PMID:25748023

  20. A Photographic Study of Freezing of Water Droplets Falling Freely in Air

    NASA Technical Reports Server (NTRS)

    Dorsch, Robert G.; Levine, Joseph

    1952-01-01

    A photographic technique for investigating water droplets of diameter less than 200 microns falling freely in air at temperatures between 0 C and -50 C has been devised and used to determine: (i) The shape of frozen droplets (2) The occurrence of collisions of partly frozen or of frozen and liquid droplets (3) The statistics on the freezing temperatures of individual free-falling droplets A considerable number of droplets were found to have a nonspherical shape after freezing because of various protuberances and frost growth, and droplet aggregates formed by collision. The observed frequency of collision of partly frozen droplets showed good order of magnitude agreement with the frequency computed from theoretical collection efficiencies. The freezing temperature statistics indicated a general similarity of the data to those obtained for droplets frozen on a metallic surface in previous experiments.

  1. Unveiling the photonic spin Hall effect of freely propagating fan-shaped cylindrical vector vortex beams.

    PubMed

    Zhang, Yi; Li, Peng; Liu, Sheng; Zhao, Jianlin

    2015-10-01

    An intriguing photonic spin Hall effect (SHE) for a freely propagating fan-shaped cylindrical vector (CV) vortex beam in a paraxial situation is theoretically and experimentally studied. A developed model to describe this kind of photonic SHE is proposed based on angular spectrum diffraction theory. With this model, the close dependences of spin-dependent splitting on the azimuthal order of polarization, the topological charge of the spiral phase, and the propagation distance are accurately revealed. Furthermore, it is demonstrated that the asymmetric spin-dependent splitting of a fan-shaped CV beam can be consciously managed, even with a constant azimuthal order of polarization. Such a controllable photonic SHE is experimentally verified by measuring the Stokes parameters.

  2. Three dimensional simulations of pattern formation during high-pressure, freely localized microwave breakdown in air

    SciTech Connect

    Kourtzanidis, K. Boeuf, J. P.; Rogier, F.

    2014-12-15

    Recent experiments have demonstrated that a freely localized 100 GHz microwave discharge can propagate towards the microwave source with high speed, forming a complex pattern of self-organized filaments. We present three-dimensional simulations of the formation and propagation of such patterns that reveal more information on their nature and interaction with the electromagnetic waves. The developed three-dimensional Maxwell-plasma solver permits the study of different forms of incident field polarization. Results for linear and circular polarization of the wave are presented and comparisons with recent experiments show a good overall agreement. The three dimensional simulations provide a quantitative analysis of the parameters controlling the time and length scales of the strongly non-linear plasma dynamics and could be useful for potential microwave plasma applications such as aerodynamic flow and combustion control.

  3. Freely designable optical frequency conversion in Raman-resonant four-wave-mixing process

    NASA Astrophysics Data System (ADS)

    Zheng, Jian; Katsuragawa, Masayuki

    2015-03-01

    Nonlinear optical processes are governed by the relative-phase relationships among the relevant electromagnetic fields in these processes. In this Report, we describe the physics of arbitrary manipulation of Raman-resonant four-wave-mixing process by artificial control of relative phases. As a typical example, we show freely designable optical-frequency conversions to extreme spectral regions, mid-infrared and vacuum-ultraviolet, with near-unity quantum efficiencies. Furthermore, we show that such optical-frequency conversions can be realized by using a surprisingly simple technology where transparent plates are placed in a nonlinear optical medium and their positions and thicknesses are adjusted precisely. In a numerical simulation assuming practically applicable parameters in detail, we demonstrate a single-frequency tunable laser that covers the whole vacuum-ultraviolet spectral range of 120 to 200 nm.

  4. An open access pilot freely sharing cancer genomic data from participants in Texas

    PubMed Central

    Becnel, Lauren B.; Pereira, Stacey; Drummond, Jennifer A.; Gingras, Marie-Claude; Covington, Kyle R.; Kovar, Christie L.; Doddapaneni, Harsha Vardhan; Hu, Jianhong; Muzny, Donna; McGuire, Amy L.; Wheeler, David A.; Gibbs, Richard A.

    2016-01-01

    Genomic data sharing in cancer has been restricted to aggregate or controlled-access initiatives to protect the privacy of research participants. By limiting access to these data, it has been argued that the autonomy of individuals who decide to participate in data sharing efforts has been superseded and the utility of the data as research and educational tools reduced. In a pilot Open Access (OA) project from the CPRIT-funded Texas Cancer Research Biobank, many Texas cancer patients were willing to openly share genomic data from tumor and normal matched pair specimens. For the first time, genetic data from 7 human cancer cases with matched normal are freely available without requirement for data use agreements nor any major restriction except that end users cannot attempt to re-identify the participants (http://txcrb.org/open.html). PMID:26882539

  5. Crucial tests of macrorealist and semiclassical gravity models with freely falling mesoscopic nanospheres

    NASA Astrophysics Data System (ADS)

    Colin, Samuel; Durt, Thomas; Willox, Ralph

    2016-06-01

    Recently, several proposals have been made to test the quantum superposition principle in the mesoscopic regime. Most of these tests consist of a careful measurement of the loss of interference due to decoherence. Here we consider, instead, the spread in position of a freely falling nanosphere. We study in depth the dependence of this spread on self-gravity in the presence of decoherence (exotic and nonexotic). We show that the influence of self-gravity is robust in the presence of weak decoherence, and quantify this robustness by introducing a parameter, the critical decoherence, aimed at estimating the critical value above which self-gravity is overwhelmed by decoherence. We also emphasize the crucial role played by the spread of the initial wave packet for the sensitivity of free-fall experiments to decoherence.

  6. An open access pilot freely sharing cancer genomic data from participants in Texas.

    PubMed

    Becnel, Lauren B; Pereira, Stacey; Drummond, Jennifer A; Gingras, Marie-Claude; Covington, Kyle R; Kovar, Christie L; Doddapaneni, Harsha Vardhan; Hu, Jianhong; Muzny, Donna; McGuire, Amy L; Wheeler, David A; Gibbs, Richard A

    2016-02-16

    Genomic data sharing in cancer has been restricted to aggregate or controlled-access initiatives to protect the privacy of research participants. By limiting access to these data, it has been argued that the autonomy of individuals who decide to participate in data sharing efforts has been superseded and the utility of the data as research and educational tools reduced. In a pilot Open Access (OA) project from the CPRIT-funded Texas Cancer Research Biobank, many Texas cancer patients were willing to openly share genomic data from tumor and normal matched pair specimens. For the first time, genetic data from 7 human cancer cases with matched normal are freely available without requirement for data use agreements nor any major restriction except that end users cannot attempt to re-identify the participants (http://txcrb.org/open.html).

  7. Apparatus for measuring the force of gravity on freely falling electrons

    NASA Technical Reports Server (NTRS)

    Witteborn, F. C.; Fairbank, W. M.

    1977-01-01

    An apparatus and data analysis technique for measuring the gravitational force on freely falling electrons are described. The measurement required that all forces acting on the electrons be uniform and measurable to about ten to the negative 11th power eV/m. The electrical force along the axis of the 5-cm-diam, vertical copper tube used in the experiment was found to be about six times ten to the negative 11th power eV/m when the tube was cooled to 4.2 K. Forces on electrons due to magnetic field gradients were reduced well below the electrical ones by selecting only ground state electrons for measurement. The absence, at 4.2 K, of much stronger electric fields, which were expected to arise from the patch effect and from differential lattice components, contrasts strongly with measurements of electric fields near metal surfaces made at room temperature.

  8. Studies of Islands on Freely Suspended Bubbles of Smectic Liquid Crystal

    NASA Technical Reports Server (NTRS)

    Pattanaporkratana, A.; Mavel, B.; Park, C. S.; Maclennan, J. E.; Clark, N. A.

    2002-01-01

    We have constructed an optical system for observing the internal structure of freely suspended smectic liquid crystal bubbles using a reflected light microscope. Liquid crystal bubbles can have thicker circular regions (islands) which can easily be generated by shrinking the bubble diameter. The diameter of these islands is approximately 10 microns and they are typically up to five times thicker than the surrounding liquid crystal film (500 angstroms). In the Laboratory, the location of the islands is strongly influenced by gravity, which causes the majority of islands to migrate to the bottom half of the bubble. We will describe the size and thickness distributions of islands and their time evolution, and also discuss two-dimensional hydrodynamics and turbulence of smectic bubbles, the shapes of islands and holes affected by bubble vibrations, and the interactions between islands, which we have probed using optical tweezers.

  9. Molecular organization in freely suspended nano-thick 8CB smectic films. An atomistic simulation.

    PubMed

    Palermo, Mattia Felice; Muccioli, Luca; Zannoni, Claudio

    2015-10-21

    We present an atomistic molecular dynamics simulation of freely suspended films of the smectic liquid crystal 8CB formed by nl = 2, 3,…,10, 20 theoretical monolayers, determining their orientational and positional order as a function of the film thickness. We find that films are always composed by bilayers of antiparallel molecules, and that in the case of odd nl, the system prefers to self-assemble in (nl + 1)/2 bilayers, with an increase of surface tension with respect to even nl samples. We also show that external layers have higher positional and orientational order, and that upon heating the disordering of the system proceeds from the inside, with the central layers progressively losing their smectic character, while the external ones are more resistant to temperature changes and keep the film from breaking.

  10. Impact and embedding of picoliter droplets into freely suspended smectic films.

    PubMed

    Dölle, Sarah; Harth, Kirsten; John, Thomas; Stannarius, Ralf

    2014-10-28

    We study the impact of liquid microdroplets on thin freely suspended smectic films. Such films are very thin but robust objects that can serve as model systems for quasi-two-dimensional liquids. Droplet velocities and sizes determine the character of the collisions. The dynamics of the integration of droplets into the film can be divided into three phases, starting with the impact and a dissipation of the kinetic energy, followed by a balancing of capillary forces within fractions of a second. The analysis of the droplet shape evolution with high-speed imaging allows us to study the dynamics of this process. The final phase, formation of a meniscus of smectic material, takes several seconds up to minutes.

  11. Freely orbiting magnetic tweezers to directly monitor changes in the twist of nucleic acids

    PubMed Central

    Lipfert, Jan; Wiggin, Matthew; Kerssemakers, Jacob W.J.; Pedaci, Francesco; Dekker, Nynke H.

    2011-01-01

    The double-stranded nature of DNA links its replication, transcription and repair to rotational motion and torsional strain. Magnetic tweezers (MT) are a powerful single-molecule technique to apply both forces and torques to individual DNA or RNA molecules. However, conventional MT do not track rotational motion directly and constrain the free rotation of the nucleic acid tether. Here we present freely orbiting MT (FOMT) that allow the measurement of equilibrium fluctuations and changes in the twist of tethered nucleic acid molecules. Using a precisely aligned vertically oriented magnetic field, FOMT enable tracking of the rotation angle from straight forward (x,y)-position tracking and permits the application of calibrated stretching forces, without biasing the tether's free rotation. We utilize FOMT to measure the force-dependent torsional stiffness of DNA from equilibrium rotational fluctuations and to follow the assembly of recombination protein A filaments on DNA. PMID:21863006

  12. AstroNavigation: Freely-available Online Instruction for Performing a Sight Reduction

    NASA Astrophysics Data System (ADS)

    Gessner Stewart, Susan; Grundstrom, Erika; Caudel, Dave

    2015-08-01

    A reliable method of obtaining your geographic location from observations of celestial bodies is globally available. This online learning module, developed through a collaboration between Vanderbilt University and the U.S. Naval Observatory, serves to address the need for freely-available comprehensive instruction in celestial navigation online. Specifically targeted are the steps of preforming a sight reduction to obtain a terrestrial position using this technique. Difficult concepts such as plotting on a navigational chart and the complexities of using navigation publications are facilitated through this online content delivery, rooted in effective course design principles. There is good potential in using celestial navigation as a tool for stimulating interest in astronomy given its resourcefulness and accessibility.

  13. Characterization of epitopes recognized by monoclonal antibodies: experimental approaches supported by freely accessible bioinformatic tools.

    PubMed

    Clementi, Nicola; Mancini, Nicasio; Castelli, Matteo; Clementi, Massimo; Burioni, Roberto

    2013-05-01

    Monoclonal antibodies (mAbs) have been used successfully both in research and for clinical purposes. The possible use of protective mAbs directed against different microbial pathogens is currently being considered. The fine definition of the epitope recognized by a protective mAb is an important aspect to be considered for possible development in epitope-based vaccinology. The most accurate approach to this is the X-ray resolution of mAb/antigen crystal complex. Unfortunately, this approach is not always feasible. Under this perspective, several surrogate epitope mapping strategies based on the use of bioinformatics have been developed. In this article, we review the most common, freely accessible, bioinformatic tools used for epitope characterization and provide some basic examples of molecular visualization, editing and computational analysis.

  14. dynamical evolution of an ultra-relativistic fireball colliding with a freely expanding gas

    SciTech Connect

    Suzuki, Akihiro; Shigeyama, Toshikazu

    2014-11-20

    We investigate the hydrodynamical evolution of an ultra-relativistic fireball colliding with a freely expanding gas. The hydrodynamical interaction of the fireball and the gas results in the formation of a geometrically thin shell. We study the dynamical evolution of the shell analytically and perform a numerical simulation equipped with adaptive mesh refinement to investigate the internal structure of the shell. The shocked gas can give rise to bright emission in the X-ray and gamma-ray energy range. We propose that the breakout emission from the forward shock and the photospheric emission from the reverse-shocked fireball contribute to early gamma-ray emission from gamma-ray bursts.

  15. The stability of freely-propagating ion acoustic waves in 2D systems

    NASA Astrophysics Data System (ADS)

    Chapman, Thomas; Berger, Richard; Banks, Jeffrey; Brunner, Stephan

    2014-10-01

    The stability of a freely-propagating ion acoustic wave (IAW) is a basic science problem that is made difficult by the need to resolve electron kinetic effects over a timescale that greatly exceeds the IAW period during numerical simulation. Recent results examining IAW stability using a 1D+1V Vlasov-Poisson solver indicate that instability is a fundamental property of IAWs that occurs over most if not all of the parameter space of relevance to ICF experiments. We present here new results addressing the fundamental question of IAW stability across a broad range of plasma conditions in a 2D+2V system using LOKI, ranging from a regime of relatively weak to a regime of relatively strong ion kinetic effects. Work performed under the auspices of the U.S. DOE by LLNL (DE-AC52-07NA27344) and funded by the LDRD Program at LLNL (12-ERD-061).

  16. A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats.

    PubMed

    Morales, Juan Carlos; Alvarez-Ferradas, Carla; Roncagliolo, Manuel; Fuenzalida, Marco; Wellmann, Mario; Nualart, Francisco Javier; Bonansco, Christian

    2014-01-01

    Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK), the rapid kindling types (RK) described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and immunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE) which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA) stimulation with 10 trains of biphasic pulses (10 s; 50 Hz) per day with 20 min-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through electroencephalographic (EEG) recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other

  17. Design and validation of Segment - freely available software for cardiovascular image analysis

    PubMed Central

    2010-01-01

    Background Commercially available software for cardiovascular image analysis often has limited functionality and frequently lacks the careful validation that is required for clinical studies. We have already implemented a cardiovascular image analysis software package and released it as freeware for the research community. However, it was distributed as a stand-alone application and other researchers could not extend it by writing their own custom image analysis algorithms. We believe that the work required to make a clinically applicable prototype can be reduced by making the software extensible, so that researchers can develop their own modules or improvements. Such an initiative might then serve as a bridge between image analysis research and cardiovascular research. The aim of this article is therefore to present the design and validation of a cardiovascular image analysis software package (Segment) and to announce its release in a source code format. Results Segment can be used for image analysis in magnetic resonance imaging (MRI), computed tomography (CT), single photon emission computed tomography (SPECT) and positron emission tomography (PET). Some of its main features include loading of DICOM images from all major scanner vendors, simultaneous display of multiple image stacks and plane intersections, automated segmentation of the left ventricle, quantification of MRI flow, tools for manual and general object segmentation, quantitative regional wall motion analysis, myocardial viability analysis and image fusion tools. Here we present an overview of the validation results and validation procedures for the functionality of the software. We describe a technique to ensure continued accuracy and validity of the software by implementing and using a test script that tests the functionality of the software and validates the output. The software has been made freely available for research purposes in a source code format on the project home page http

  18. A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats

    PubMed Central

    Morales, Juan Carlos; Álvarez-Ferradas, Carla; Roncagliolo, Manuel; Fuenzalida, Marco; Wellmann, Mario; Nualart, Francisco Javier; Bonansco, Christian

    2014-01-01

    Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK), the rapid kindling types (RK) described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and immunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE) which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA) stimulation with 10 trains of biphasic pulses (10 s; 50 Hz) per day with 20 min-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through electroencephalographic (EEG) recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other

  19. High-speed tracking of rupture and clustering in freely falling granular streams

    NASA Astrophysics Data System (ADS)

    Royer, John R.

    It is a common, well known occurrence for a thin liquid stream to break up into droplets due to the surface-tension driven Plateau-Rayleigh instability [1]. Surprisingly, this effect can also occur in granular materials, where an initially uniform stream of grains breaks up into discrete clusters, or droplets, of grains, even though granular materials are generally considered to lack surface tension. This thesis investigates this break up in a stream of grains freely falling out of a nozzle. We employ high-speed video imaging in the co-moving frame with the freely-falling granular stream, which allows us to track the onset of clustering and the subsequent cluster evolution in detail. By directly measuring grain-grain interactions with Atomic Force Microscopy (AFM) and carefully controlling the surface properties of the grains, we demonstrate that the cluster formation is driven by minute, nanoNewton cohesive forces due to a combination of van der Waals interactions and capillary bridges between nanoscale surface asperities. The shapes of these weakly cohesive, non-thermal clusters of macroscopic particles closely resemble droplets resulting from thermally induced rupture of liquid nanojets and ultra-low surface tension fluids. Like in the liquid break up, the size of the clusters is determined solely by the stream width and independent of particle-scale details though the range of selected aspect ratios differs from the fluid case. The scaling for the minimum neck diameter near break up is consistent with the scaling for an inviscid liquid, allowing us to extract an effect surface tension nearly four orders of magnitude lower than in normal liquids. These free falling streams are both an exquisite probe of the weak interactions between grains and a unique system to probe the ultra-low surface tension fluid regime in the absence of thermal fluctuations.

  20. Energetically optimal cadence vs. freely-chosen cadence during cycling: effect of exercise duration.

    PubMed

    Brisswalter, J; Hausswirth, C; Smith, D; Vercruyssen, F; Vallier, J M

    2000-01-01

    The purpose of this study was to examine the relationship between cadence and oxygen consumption with exercise duration. Ten triathletes who trained regularly were examined. The first test was always a maximal test to determine maximal oxygen uptake (VO2max). The other sessions were composed of six submaximal tests representing 80% of the maximal power reached with VO2max (Pmax). During these tests submaximal rides with a duration of 30 min were performed. Each test represented, in a randomised order, one of the following pedal rates: 50, 65, 80, 95, 110 rpm and a freely-chosen rate. VO2, respiratory parameters, and heart rate were monitored continuously. Two periods, between the 3rd and the 6th minute and between the 25th and the 28th minute, were analysed. Results showed that when VO2 and heart rate were plotted against cadence, each curve could be best described by a parabolic function, whatever the period. Furthermore, a significant effect of period was found on energetically optimal cadence (70 +/- 4.5 vs. 86 +/- 6.2 rpm, P < 0.05). Only during the second period was no significant difference found between freely-chosen cadence (83 +/- 6.9 rpm) and energetically optimal cadence (P > 0.05). In conclusion, our results suggest that during prolonged exercise triathletes choose a cadence that is close to the energetically optimal cadence. A change of muscle fibre recruitment pattern with exercise duration and cadence would explain the shift in energetically optimal rate towards a higher pedal rate observed at the end of exercise. PMID:10683101

  1. A new rapid kindling variant for induction of cortical epileptogenesis in freely moving rats.

    PubMed

    Morales, Juan Carlos; Alvarez-Ferradas, Carla; Roncagliolo, Manuel; Fuenzalida, Marco; Wellmann, Mario; Nualart, Francisco Javier; Bonansco, Christian

    2014-01-01

    Kindling, one of the most used models of experimental epilepsy is based on daily electrical stimulation in several brain structures. Unlike the classic or slow kindling protocols (SK), the rapid kindling types (RK) described until now require continuous stimulation at suprathreshold intensities applied directly to the same brain structure used for subsequent electrophysiological and immunohistochemical studies, usually the hippocampus. However, the cellular changes observed in these rapid protocols, such as astrogliosis and neuronal loss, could be due to experimental manipulation more than to epileptogenesis-related alterations. Here, we developed a new RK protocol in order to generate an improved model of temporal lobe epilepsy (TLE) which allows gradual progression of the epilepsy as well as obtaining an epileptic hippocampus, thus avoiding direct surgical manipulation and electric stimulation over this structure. This new protocol consists of basolateral amygdala (BLA) stimulation with 10 trains of biphasic pulses (10 s; 50 Hz) per day with 20 min-intervals, during 3 consecutive days, using a subconvulsive and subthreshold intensity, which guarantees tissue integrity. The progression of epileptic activity was evaluated in freely moving rats through electroencephalographic (EEG) recordings from cortex and amygdala, accompanied with synchronized video recordings. Moreover, we assessed the effectiveness of RK protocol and the establishment of epilepsy by evaluating cellular alterations of hippocampal slices from kindled rats. RK protocol induced convulsive states similar to SK protocols but in 3 days, with persistently lowered threshold to seizure induction and epileptogenic-dependent cellular changes in amygdala projection areas. We concluded that this novel RK protocol introduces a new variant of the chronic epileptogenesis models in freely moving rats, which is faster, highly reproducible and causes minimum cell damage with respect to that observed in other

  2. Attenuation correction for freely moving small animal brain PET studies based on a virtual scanner geometry

    NASA Astrophysics Data System (ADS)

    Angelis, G. I.; Kyme, A. Z.; Ryder, W. J.; Fulton, R. R.; Meikle, S. R.

    2014-10-01

    Attenuation correction in positron emission tomography brain imaging of freely moving animals is a very challenging problem since the torso of the animal is often within the field of view and introduces a non negligible attenuating factor that can degrade the quantitative accuracy of the reconstructed images. In the context of unrestrained small animal imaging, estimation of the attenuation correction factors without the need for a transmission scan is highly desirable. An attractive approach that avoids the need for a transmission scan involves the generation of the hull of the animal’s head based on the reconstructed motion corrected emission images. However, this approach ignores the attenuation introduced by the animal’s torso. In this work, we propose a virtual scanner geometry which moves in synchrony with the animal’s head and discriminates between those events that traversed only the animal’s head (and therefore can be accurately compensated for attenuation) and those that might have also traversed the animal’s torso. For each recorded pose of the animal’s head a new virtual scanner geometry is defined and therefore a new system matrix must be calculated leading to a time-varying system matrix. This new approach was evaluated on phantom data acquired on the microPET Focus 220 scanner using a custom-made phantom and step-wise motion. Results showed that when the animal’s torso is within the FOV and not appropriately accounted for during attenuation correction it can lead to bias of up to 10% . Attenuation correction was more accurate when the virtual scanner was employed leading to improved quantitative estimates (bias < 2%), without the need to account for the attenuation introduced by the extraneous compartment. Although the proposed method requires increased computational resources, it can provide a reliable approach towards quantitatively accurate attenuation correction for freely moving animal studies.

  3. The respiratory chain in yeast behaves as a single functional unit.

    PubMed

    Boumans, H; Grivell, L A; Berden, J A

    1998-02-27

    Inhibitor titrations using antimycin have been used to study the pool behavior of ubiquinone and cytochrome c in the respiratory chain of the yeast Saccharomyces cerevisiae. If present in a homogeneous pool, these carriers should be able to diffuse freely through or along the membrane respectively and accept and subsequently donate electrons to an infinite number of the respective respiratory complex. However, we show that under physiological conditions neither ubiquinone nor cytochrome c exhibits pool behavior, implying that the respiratory chain in yeast is one functional unit. Pool behavior can be introduced for both small carriers by adding chaotropic agents to the reaction medium. We conclude that these agents disrupt the interaction between the respiratory complexes, thereby causing them to become randomly arranged in the membrane. In such a situation, ubiquinone and cytochrome c become mobile carriers, shuttling between the large respiratory complexes. Furthermore, we conclude from the respiratory activities found for different substrates that the respiratory units in yeast vary in composition with respect to the ubiquinone reducing enzyme. All units contain the cytochrome chain, supplemented with either succinate dehydrogenase or the internal or the external NADH dehydrogenase. This implies that when only one substrate is available, only a certain fraction of the cytochrome chain is used in respiration. The molecular organization of the respiratory chain in yeast is compared with that of higher eukaryotes and to the electron transfer systems of photosynthetic membranes. Differences between the organization of the respiratory chain of yeast and that of higher eukaryotes are discussed in terms of the ability of yeast to radically alter its metabolism in response to change of the available carbon source.

  4. Distinct BOLD Activation Profiles Following Central and Peripheral Oxytocin Administration in Awake Rats

    PubMed Central

    Ferris, Craig F.; Yee, Jason R.; Kenkel, William M.; Dumais, Kelly Marie; Moore, Kelsey; Veenema, Alexa H.; Kulkarni, Praveen; Perkybile, Allison M.; Carter, C. Sue

    2015-01-01

    A growing body of literature has suggested that intranasal oxytocin (OT) or other systemic routes of administration can alter prosocial behavior, presumably by directly activating OT sensitive neural circuits in the brain. Yet there is no clear evidence that OT given peripherally can cross the blood–brain barrier at levels sufficient to engage the OT receptor. To address this issue we examined changes in blood oxygen level-dependent (BOLD) signal intensity in response to peripheral OT injections (0.1, 0.5, or 2.5 mg/kg) during functional magnetic resonance imaging (fMRI) in awake rats imaged at 7.0 T. These data were compared to OT (1 μg/5 μl) given directly to the brain via the lateral cerebroventricle. Using a 3D annotated MRI atlas of the rat brain segmented into 171 brain areas and computational analysis, we reconstructed the distributed integrated neural circuits identified with BOLD fMRI following central and peripheral OT. Both routes of administration caused significant changes in BOLD signal within the first 10 min of administration. As expected, central OT activated a majority of brain areas known to express a high density of OT receptors, e.g., lateral septum, subiculum, shell of the accumbens, bed nucleus of the stria terminalis. This profile of activation was not matched by peripheral OT. The change in BOLD signal to peripheral OT did not show any discernible dose–response. Interestingly, peripheral OT affected all subdivisions of the olfactory bulb, in addition to the cerebellum and several brainstem areas relevant to the autonomic nervous system, including the solitary tract nucleus. The results from this imaging study do not support a direct central action of peripheral OT on the brain. Instead, the patterns of brain activity suggest that peripheral OT may interact at the level of the olfactory bulb and through sensory afferents from the autonomic nervous system to influence brain activity. PMID:26441574

  5. Gating of tactile information through gamma band during passive arm movement in awake primates

    PubMed Central

    Song, Weiguo; Francis, Joseph T.

    2015-01-01

    To make precise and prompt action in a dynamic environment, the sensorimotor system needs to integrate all related information. The inflow of somatosensory information to the cerebral cortex is regulated and mostly suppressed by movement, which is commonly referred to as sensory gating or gating. Sensory gating plays an important role in preventing redundant information from reaching the cortex, which should be considered when designing somatosensory neuroprosthetics. Gating can occur at several levels within the sensorimotor pathway, while the underlying mechanism is not yet fully understood. The average sensory evoked potential is commonly used to assess sensory information processing, however the assumption of a stereotyped response to each stimulus is still an open question. Event related spectral perturbation (ERSP), which is the power spectrum after time-frequency decomposition on single trial evoked potentials (total power), could overcome this limitation of averaging and provide additional information for understanding the underlying mechanism. To this aim, neural activities in primary somatosensory cortex (S1), primary motor cortex (M1), and ventral posterolateral (VPL) nucleus of thalamus were recorded simultaneously in two areas (S1 and M1 or S1 and VPL) during passive arm movement and rest in awake monkeys. Our results showed that neural activity at different recording areas demonstrated specific and unique response frequency characteristics. Tactile input induced early high frequency responses followed by low frequency oscillations within sensorimotor circuits, and passive movement suppressed these oscillations either in a phase-locked or non-phase-locked manner. Sensory gating by movement was non-phase-locked in M1, and complex in sensory areas. VPL showed gating of non-phase-locked at gamma band and mix of phase-locked and non-phase-locked at low frequency, while S1 showed gating of phase-locked and non-phase-locked at gamma band and an early phase

  6. Differing Presynaptic Contributions to LTP and Associative Learning in Behaving Mice

    PubMed Central

    Madroñal, Noelia; Gruart, Agnès; Delgado-García, José M.

    2009-01-01

    The hippocampal CA3-CA1 synapse is an excellent experimental model for studying the interactions between short- and long-term plastic changes taking place following high-frequency stimulation (HFS) of Schaffer collaterals and during the acquisition and extinction of a classical eyeblink conditioning in behaving mice. Input/output curves and a full-range paired-pulse study enabled determining the optimal intensities and inter-stimulus intervals for evoking paired-pulse facilitation (PPF) or depression (PPD) at the CA3-CA1 synapse. Long-term potentiation (LTP) induced by HFS lasted ≈10 days. HFS-induced LTP evoked an initial depression of basal PPF. Recovery of PPF baseline values was a steady and progressive process lasting ≈20 days, i.e., longer than the total duration of the LTP. In a subsequent series of experiments, we checked whether PPF was affected similarly during activity-dependent synaptic changes. Animals were conditioned using a trace paradigm, with a tone as a conditioned stimulus (CS) and an electrical shock to the trigeminal nerve as an unconditioned stimulus (US). A pair of pulses (40 ms interval) was presented to the Schaffer collateral-commissural pathway to evoke field EPSPs (fEPSPs) during the CS-US interval. Basal PPF decreased steadily across conditioning sessions (i.e., in the opposite direction to that during LTP), reaching a minimum value during the 10th conditioning session. Thus, LTP and classical eyeblink conditioning share some presynaptic mechanisms, but with an opposite evolution. Furthermore, PPF and PPD might play a homeostatic role during long-term plastic changes at the CA3-CA1 synapse. PMID:19636387

  7. Polymorphic Chromosomes Bearing the Tox2 Locus in Cochliobolus carbonum Behave as Homologs during Meiosis

    PubMed Central

    Canada, S. R.; Dunkle, L. D.

    1997-01-01

    The HTS1 gene in the Tox2 locus of the fungal pathogen Cochliobolus carbonum race 1 is required for synthesis of a host-selective phytotoxin and for increased virulence on susceptible genotypes of maize. The locus is present in race 1 isolates but absent from isolates of the other races, which do not produce the toxin. By pulsed-field gel electrophoresis and Southern analysis with HTS1 sequences and chromosome-specific markers, the HTS1 gene was detected on a 4-Mb chromosome in one group of isolates and on a 2.3-Mb chromosome in another group, which lacked the 4-Mb chromosome. A chromosome-specific marker from C. heterostrophus hybridized to a 2.3-Mb chromosome in non-toxin-producing isolates and in toxin-producing isolates, including those with a 4-Mb chromosome. A marker from C. carbonum hybridized to the 4-Mb chromosome, but in isolates lacking the 4-Mb chromosome, this marker hybridized to a smaller, 2.0-Mb chromosome. Thus, the Tox2 locus is on different chromosomes in different groups of race 1 isolates. Single ascospore progeny from crosses between isolates having HTS1 on different chromosomes were analyzed for toxin-producing ability, virulence, and the presence and chromosomal location of HTS1. All progeny produced HC toxin in culture, incited race 1-type lesions on susceptible maize genotypes, and contained HTS1 sequences, as determined by PCR amplification with gene-specific primers. Analysis of the chromosomal complements of several progeny indicated that they all had only one Tox2-containing chromosome. Thus, despite their differences in size, these chromosomes behave as homologs during meiosis and may have arisen by a translocation. PMID:16535561

  8. Riding on the fast lane: how sea turtles behave in post-nesting migration

    NASA Astrophysics Data System (ADS)

    Wang, Y.-H.; Cheng, I.-J.; Centurioni, L.

    2014-07-01

    Sea turtles are known as powerful swimmers. How do they behave when riding in strong currents during their migrations? In this study, three, satellite-tagged, post-nesting green turtles travelled from Lanyu Island, east of Taiwan, partly within the Kuroshio to their foraging sites approximately 1000 km away in the Ryukyu Archipelago. Their swimming behaviors were analyzed by comparing their migration velocities estimated from Argos tag data with ocean currents derived from a data simulation model and from AVISO advection estimates. Results suggest that the turtles take advantage of Kuroshio during the initial portion of their migration routes. They must then make a great effort to swim eastward, at speeds over 1 m s-1, toward their foraging sites to avoid being carried off course by the strong current. The cues that might cause the change in swimming direction were evaluated with a Principle Component Analysis. The factors considered are ambient current velocity, wind, eddy activity (vorticity), magnetic field (latitude) and water temperature. The analysis shows that the ambient current and water temperature are negatively correlated with the eastward swimming velocity. This suggests that the changes in ocean current and a drop of water temperature, likely due to eddies impinging on the Kuroshio, may trigger the eastward swimming. Despite the differences among migratory routes of three Argos-tagged turtles after leaving the Kuroshio, they all reached foraging sites in the same general area. That suggests there may be more complex cues that guide the turtles to their foraging sites during their post-nesting migrations.

  9. Colonizing while migrating: how do individual enteric neural crest cells behave?

    PubMed Central

    2014-01-01

    Background Directed cell migration is essential for normal development. In most of the migratory cell populations that have been analyzed in detail to date, all of the cells migrate as a collective from one location to another. However, there are also migratory cell populations that must populate the areas through which they migrate, and thus some cells get left behind while others advance. Very little is known about how individual cells behave to achieve concomitant directional migration and population of the migratory route. We examined the behavior of enteric neural crest-derived cells (ENCCs), which must both advance caudally to reach the anal end and populate each gut region. Results The behavior of individual ENCCs was examined using live imaging and mice in which ENCCs express a photoconvertible protein. We show that individual ENCCs exhibit very variable directionalities and speed; as the migratory wavefront of ENCCs advances caudally, each gut region is populated primarily by some ENCCs migrating non-directionally. After populating each region, ENCCs remain migratory for at least 24 hours. Endothelin receptor type B (EDNRB) signaling is known to be essential for the normal advance of the ENCC population. We now show that perturbation of EDNRB principally affects individual ENCC speed rather than directionality. The trajectories of solitary ENCCs, which occur transiently at the wavefront, were consistent with an unbiased random walk and so cell-cell contact is essential for directional migration. ENCCs migrate in close association with neurites. We showed that although ENCCs often use neurites as substrates, ENCCs lead the way, neurites are not required for chain formation and neurite growth is more directional than the migration of ENCCs as a whole. Conclusions Each gut region is initially populated by sub-populations of ENCCs migrating non-directionally, rather than stopping. This might provide a mechanism for ensuring a uniform density of ENCCs along the

  10. Behavioral and electrophysiological changes induced by acetyl-L-carnitine in aged freely-moving rats.

    PubMed

    Marini, G; Calvani, M; Ceccarelli, P; Mancia, M

    2006-02-01

    In chronically-implanted, drug-free, behaving aged Fischer rats, intracerebroventricularly (i.c.v.) and intraperitoneally (i.p.) acetyl-L-carnitine (ALCAR) injections powerfully enhanced motor behavior and head movements aimed at attention and exploratory activity. This effect was dose-dependent and associated with the abolition or substantial reduction of the incidence and duration of the spontaneous EEG generalized hypersynchronous patterns termed High Voltage Spindle (HVS), with an increase in EEG monitored theta activity. The results suggest that ALCAR may stimulate the motivational system and disrupt the hypersynchronous processes by inhibiting the GABAergic thalamic reticular neurons and/or activating the brain stem cholinergic reticular system (pedunculo pontine tegmental, PPT and laterodorsal tegmental, LDT nuclei). PMID:16425616

  11. Juxtacellular recording and morphological identification of single neurons in freely moving rats.

    PubMed

    Tang, Qiusong; Brecht, Michael; Burgalossi, Andrea

    2014-10-01

    It is well established that neural circuits consist of a great diversity of cell types, but very little is known about how neuronal diversity contributes to cognition and behavior. One approach to addressing this problem is to directly link cellular diversity to neuronal activity recorded in vivo in behaving animals. Here we describe the technical procedures for obtaining juxtacellular recordings from single neurons in trained rats engaged in exploratory behavior. The recorded neurons can be labeled to allow subsequent anatomical identification. In its current format, the protocol can be used for resolving the cellular identity of spatially modulated neurons (i.e., head-direction cells and grid cells), which form the basis of the animal's internal representation of space, but this approach can easily be extended to other unrestrained behaviors. The procedures described here, from the beginning of animal training to the histological processing of brain sections, can be completed in ≈ 3-4 weeks.

  12. Five-Minute Awake Snoring Test for Determining CPAP Pressures (Five-Minute CPAP Test): A Pilot Study.

    PubMed

    Camacho, Macario; Ruoff, Chad M; Kawai, Makoto; Modi, Rahul; Arbee, Jabri; Hekmat, Anahid; Robertson, Matthew; Zaghi, Soroush; Certal, Victor; Capasso, Robson; Kushida, Clete A

    2016-01-01

    Objective. To develop a quick, simple, bedside test for determining continuous positive airway pressures (CPAP) for obstructive sleep apnea (OSA) patients. Study Design. Prospective case series at a tertiary medical center. Methods. The Five-Minute Awake Snoring Test for Determining CPAP (Five-Minute CPAP Test) was developed and tested. Patients wear a soft-gel nasal triangle mask while holding a tongue depressor with the wide section (1.75 cm) between the teeth. Fixed pressure nasal CPAP is applied while the patient simulates snoring at 4 centimeters of water pressure. The pressure is incrementally titrated up and then down to determine the lowest pressure at which the patient cannot snore (Quiet Pressure). Results. Overall, thirty-eight patients participated. All could simulate snoring. Correlation coefficients were statistically significant between Quiet Pressures and body mass index (r s = 0.60 [strong positive relationship], p = 0.0088), apnea-hypopnea index (r s = 0.49 [moderate positive relationship], p = 0.039), lowest oxygen saturation (r s = -0.47 [moderate negative relationship], p = 0.048), and oxygen desaturation index (r s = 0.62 [strong positive relationship], p = 0.0057). Conclusion. This pilot study introduces a new concept, which is the final product of over one year of exploration, development, and testing. Five-Minute CPAP Test is a quick, inexpensive, and safe bedside test based on supine awake simulated snoring with nasal CPAP.

  13. A comparison of the Enk Fiberoptic Atomizer Set(™) with boluses of topical anaesthesia for awake fibreoptic intubation.

    PubMed

    Pirlich, N; Lohse, J A; Schmidtmann, I; Didion, N; Piepho, T; Noppens, R R

    2016-07-01

    We compared the Enk Fiberoptic Atomizer Set(™) with boluses of topical anaesthesia administered via the working channel during awake fibreoptic tracheal intubation in 96 patients undergoing elective surgery. Patients who received topical anaesthesia via the atomiser, compared with boluses via the fibreoptic scope, reported a better median (IQR [range]) level of comfort: 1 (1-3 [1-10]) vs. 4 (2-6 [1-10]), p < 0.0001; experienced a reduced total number of coughs: 6 (3-10 [0-34]) vs. 11 (6-13 [0-25]), p = 0.0055; and fewer distinct coughing episodes: 7% vs. 27% respectively, p = 0.0133. The atomiser technique was quicker: 5 (3-6 [2-12]) min vs. 6 (5-7 [2-15]) min, p = 0.0009; and required less topical lidocaine: 100 mg (100-100 [80-160]) vs. 200 mg (200-200 [200-200]), p < 0.0001. Four weeks after nasal intubation, the incidence of nasal pain was less in the atomiser group compared with the control group (8% vs. 50%, p = 0.0015). We conclude that the atomiser was superior to bolus application for awake fibreoptic tracheal intubation. PMID:27150724

  14. Five-Minute Awake Snoring Test for Determining CPAP Pressures (Five-Minute CPAP Test): A Pilot Study

    PubMed Central

    Camacho, Macario; Ruoff, Chad M.; Kawai, Makoto; Modi, Rahul; Arbee, Jabri; Hekmat, Anahid; Robertson, Matthew; Certal, Victor; Capasso, Robson; Kushida, Clete A.

    2016-01-01

    Objective. To develop a quick, simple, bedside test for determining continuous positive airway pressures (CPAP) for obstructive sleep apnea (OSA) patients. Study Design. Prospective case series at a tertiary medical center. Methods. The Five-Minute Awake Snoring Test for Determining CPAP (Five-Minute CPAP Test) was developed and tested. Patients wear a soft-gel nasal triangle mask while holding a tongue depressor with the wide section (1.75 cm) between the teeth. Fixed pressure nasal CPAP is applied while the patient simulates snoring at 4 centimeters of water pressure. The pressure is incrementally titrated up and then down to determine the lowest pressure at which the patient cannot snore (Quiet Pressure). Results. Overall, thirty-eight patients participated. All could simulate snoring. Correlation coefficients were statistically significant between Quiet Pressures and body mass index (rs = 0.60 [strong positive relationship], p = 0.0088), apnea-hypopnea index (rs = 0.49 [moderate positive relationship], p = 0.039), lowest oxygen saturation (rs = −0.47 [moderate negative relationship], p = 0.048), and oxygen desaturation index (rs = 0.62 [strong positive relationship], p = 0.0057). Conclusion. This pilot study introduces a new concept, which is the final product of over one year of exploration, development, and testing. Five-Minute CPAP Test is a quick, inexpensive, and safe bedside test based on supine awake simulated snoring with nasal CPAP. PMID:26881088

  15. Automated long-term tracking of freely moving animal and functional brain imaging based on fiber optic microscopy

    NASA Astrophysics Data System (ADS)

    Cha, Jaepyeong; Cheon, Gyeong Woo; Kang, Jin U.

    2015-03-01

    In this study, we demonstrate an automated data acquisition/analysis platform for both long-term motion tracking and functional brain imaging in freely moving mice. Our system utilizes a fiber-bundle based fluorescence microscope for 24 hours imaging of cellular activities within the brain while also monitoring corresponding animal behaviors using a NIR camera. Synchronized software and automation of analysis allow quantification of all animal behaviors and their brain activities over extended periods of time. Our platform can be used for interrogation of the brain activities in different behavioral states and is also well-suited for longitudinal studies of cellular activities in freely moving animals.

  16. FRETBursts: An Open Source Toolkit for Analysis of Freely-Diffusing Single-Molecule FRET.

    PubMed

    Ingargiola, Antonino; Lerner, Eitan; Chung, SangYoon; Weiss, Shimon; Michalet, Xavier

    2016-01-01

    Single-molecule Förster Resonance Energy Transfer (smFRET) allows probing intermolecular interactions and conformational changes in biomacromolecules, and represents an invaluable tool for studying cellular processes at the molecular scale. smFRET experiments can detect the distance between two fluorescent labels (donor and acceptor) in the 3-10 nm range. In the commonly employed confocal geometry, molecules are free to diffuse in solution. When a molecule traverses the excitation volume, it emits a burst of photons, which can be detected by single-photon avalanche diode (SPAD) detectors. The intensities of donor and acceptor fluorescence can then be related to the distance between the two fluorophores. While recent years have seen a growing number of contributions proposing improvements or new techniques in smFRET data analysis, rarely have those publications been accompanied by software implementation. In particular, despite the widespread application of smFRET, no complete software package for smFRET burst analysis is freely available to date. In this paper, we introduce FRETBursts, an open source software for analysis of freely-diffusing smFRET data. FRETBursts allows executing all the fundamental steps of smFRET bursts analysis using state-of-the-art as well as novel techniques, while providing an open, robust and well-documented implementation. Therefore, FRETBursts represents an ideal platform for comparison and development of new methods in burst analysis. We employ modern software engineering principles in order to minimize bugs and facilitate long-term maintainability. Furthermore, we place a strong focus on reproducibility by relying on Jupyter notebooks for FRETBursts execution. Notebooks are executable documents capturing all the steps of the analysis (including data files, input parameters, and results) and can be easily shared to replicate complete smFRET analyzes. Notebooks allow beginners to execute complex workflows and advanced users to

  17. Impact of extraneous mispositioned events on motion-corrected brain SPECT images of freely moving animals

    SciTech Connect

    Angelis, Georgios I. Ryder, William J.; Bashar, Rezaul; Meikle, Steven R.; Fulton, Roger R.

    2014-09-15

    Purpose: Single photon emission computed tomography (SPECT) brain imaging of freely moving small animals would allow a wide range of important neurological processes and behaviors to be studied, which are normally inhibited by anesthetic drugs or precluded due to the animal being restrained. While rigid body motion of the head can be tracked and accounted for in the reconstruction, activity in the torso may confound brain measurements, especially since motion of the torso is more complex (i.e., nonrigid) and not well correlated with that of the head. The authors investigated the impact of mispositioned events and attenuation due to the torso on the accuracy of motion corrected brain images of freely moving mice. Methods: Monte Carlo simulations of a realistic voxelized mouse phantom and a dual compartment phantom were performed. Each phantom comprised a target and an extraneous compartment which were able to move independently of each other. Motion correction was performed based on the known motion of the target compartment only. Two SPECT camera geometries were investigated: a rotating single head detector and a stationary full ring detector. The effects of motion, detector geometry, and energy of the emitted photons (hence, attenuation) on bias and noise in reconstructed brain regions were evaluated. Results: The authors observed two main sources of bias: (a) motion-related inconsistencies in the projection data and (b) the mismatch between attenuation and emission. Both effects are caused by the assumption that the orientation of the torso is difficult to track and model, and therefore cannot be conveniently corrected for. The motion induced bias in some regions was up to 12% when no attenuation effects were considered, while it reached 40% when also combined with attenuation related inconsistencies. The detector geometry (i.e., rotating vs full ring) has a big impact on the accuracy of the reconstructed images, with the full ring detector being more

  18. FRETBursts: An Open Source Toolkit for Analysis of Freely-Diffusing Single-Molecule FRET

    PubMed Central

    Lerner, Eitan; Chung, SangYoon; Weiss, Shimon; Michalet, Xavier

    2016-01-01

    Single-molecule Förster Resonance Energy Transfer (smFRET) allows probing intermolecular interactions and conformational changes in biomacromolecules, and represents an invaluable tool for studying cellular processes at the molecular scale. smFRET experiments can detect the distance between two fluorescent labels (donor and acceptor) in the 3-10 nm range. In the commonly employed confocal geometry, molecules are free to diffuse in solution. When a molecule traverses the excitation volume, it emits a burst of photons, which can be detected by single-photon avalanche diode (SPAD) detectors. The intensities of donor and acceptor fluorescence can then be related to the distance between the two fluorophores. While recent years have seen a growing number of contributions proposing improvements or new techniques in smFRET data analysis, rarely have those publications been accompanied by software implementation. In particular, despite the widespread application of smFRET, no complete software package for smFRET burst analysis is freely available to date. In this paper, we introduce FRETBursts, an open source software for analysis of freely-diffusing smFRET data. FRETBursts allows executing all the fundamental steps of smFRET bursts analysis using state-of-the-art as well as novel techniques, while providing an open, robust and well-documented implementation. Therefore, FRETBursts represents an ideal platform for comparison and development of new methods in burst analysis. We employ modern software engineering principles in order to minimize bugs and facilitate long-term maintainability. Furthermore, we place a strong focus on reproducibility by relying on Jupyter notebooks for FRETBursts execution. Notebooks are executable documents capturing all the steps of the analysis (including data files, input parameters, and results) and can be easily shared to replicate complete smFRET analyzes. Notebooks allow beginners to execute complex workflows and advanced users to

  19. Regional Metabolite Levels and Turnover in the Awake Rat Brain under the Influence of Nicotine

    PubMed Central

    Wang, Jie; Jiang, Lihong; Jiang, Yifeng; Ma, Xiaoxian; Graeme, F. Mason

    2010-01-01

    As one of the most widespread drugs of abuse, nicotine has long been known to impact the brain, particularly with respect to addiction. However, the regional effects of nicotine on the concentrations and kinetics of amino acid neurotransmitters and some energetically related neurochemicals have been little studied. In this investigation, acute effects of nicotine were measured by 1H-observed/13C-edited nuclear magnetic resonance spectroscopy method in extracts obtained from nicotine-naïve, freely moving rats given 0.7 mg/kg nicotine or saline, with [1-13C] glucose to track metabolism. Nicotine was observed to exert significant effects on the concentrations of N-acetylaspartate (NAA), and γ-aminobutyric acid (GABA), particularly in the striatum. Nicotine decreased brain glucose oxidation, glutamate-glutamine neurotransmitter cycling, and GABA synthesis regionally, including in the parietal and occipital cortices and the striatum. The olfactory bulb showed kinetics that differed markedly from those observed in the rest of the brain. Independently of nicotine, the concentration of glutamate was found to be correlated significantly with levels of NAA and GABA, suggesting a potential interplay of energetics and excitatory and inhibitory neurotransmission. In summary, the study revealed that the neurochemicals were most affected in the cortex and striatum of the rat brain after acute nicotine treatment. PMID:20345764

  20. Tectonic Loading of Crustal Faults: How does the Lower Crust behave?

    NASA Astrophysics Data System (ADS)

    Sagiya, T.; Asahi, Y.; Ohzono, M.; Hashimoto, M.; Hoso, Y.; Wada, Y.; Hirahara, K.; Takeuchi, A.; Nishimura, T.

    2008-12-01

    Tectonic loading process of intraplate earthquakes is an important but unsolved problem. In particular, mechanical behavior of the lower crust is not well known and the role of the lower crust in stress build-up at crustal faults has not been well understood. We have been conducting a dense GPS observation around two active fault systems, the Atotsugawa Fault and the Itoigawa-Shizuoka Tectonic Line fault system (ISTL), in central Japan. For the Atotsugawa Fault and the Gofukuji Fault, the central segment of ISTL, GPS observation revealed a typical deformation pattern reflecting elastic loading of a strike slip fault system. In both cases, a transcurrent block motion with a lo