Functional double dissociation within the entorhinal cortex for visual scene-dependent choice behavior

PubMed Central

Yoo, Seung-Woo; Lee, Inah

2017-01-01

How visual scene memory is processed differentially by the upstream structures of the hippocampus is largely unknown. We sought to dissociate functionally the lateral and medial subdivisions of the entorhinal cortex (LEC and MEC, respectively) in visual scene-dependent tasks by temporarily inactivating the LEC and MEC in the same rat. When the rat made spatial choices in a T-maze using visual scenes displayed on LCD screens, the inactivation of the MEC but not the LEC produced severe deficits in performance. However, when the task required the animal to push a jar or to dig in the sand in the jar using the same scene stimuli, the LEC but not the MEC became important. Our findings suggest that the entorhinal cortex is critical for scene-dependent mnemonic behavior, and the response modality may interact with a sensory modality to determine the involvement of the LEC and MEC in scene-based memory tasks. DOI: http://dx.doi.org/10.7554/eLife.21543.001 PMID:28169828

Effects of D-cycloserine and aniracetam on spatial learning in rats with entorhinal cortex lesions.

PubMed

Zajaczkowski, W; Danysz, W

1997-01-01

A great body of behavioural and neurophysiological evidence suggests that excitatory amino acids are involved in mechanisms of learning and memory. Moreover, degeneration of glutamatergic pathways may underlie the cognitive deficits seen in various disorders such as Alzheimer's dementia. As direct stimulation of glutamatergic receptors with agonists may increase the risk of toxicity and accelerate neuropathological changes, a more valid approach seems to be positive modulation of glutamatergic receptors that may reverse the symptoms with a lower risk of excitotoxic effects. Such a possibility offered by partial agonists of the strychnine-insensitive glycine site of the NMDA receptor (Gly-B site) or positive modulators of AMPA receptors, such as aniracetam. In the present study, the effects of d-cycloserine and aniracetam were tested in two animal models of cognitive deficits (entorhinal cortex lesion-induced deficits evaluated in the radial maze and scopolamine-induced amnesia evaluated in passive avoidance test). D-cycloserine (6 mg/kg, for 10 days) had no effect on spatial working memory deficit induced by entorhinal cortex lesions. It did, however, reverse scopolamine-induced deficits in the passive avoidance test when given acutely at the same dose. In contrast, aniracetam (50 mg/kg, for 10 days) produced beneficial effects in the radial maze test in rats with entorhinal cortex lesions, but given at the same dose acutely did not influence scopolamine-induced amnesia. The positive effect of d-cycloserine against scopolamine-induced amnesia may be probably related to the cholinergic-glutamatergic interaction in the hippocampus. The negative data obtained with d-cycloserine in the model of entorhinal cortex lesions-induced cognitive deficits could be taken as a hint that it is probably not suitable for the symptomatological therapy of Alzheimer's disease. The mechanism of positive action of aniracetam cannot be explained on the basis of AMPA receptor modulation

Lateral Entorhinal Cortex is Critical for Novel Object-Context Recognition

PubMed Central

Wilson, David IG; Langston, Rosamund F; Schlesiger, Magdalene I; Wagner, Monica; Watanabe, Sakurako; Ainge, James A

2013-01-01

Episodic memory incorporates information about specific events or occasions including spatial locations and the contextual features of the environment in which the event took place. It has been modeled in rats using spontaneous exploration of novel configurations of objects, their locations, and the contexts in which they are presented. While we have a detailed understanding of how spatial location is processed in the brain relatively little is known about where the nonspatial contextual components of episodic memory are processed. Initial experiments measured c-fos expression during an object-context recognition (OCR) task to examine which networks within the brain process contextual features of an event. Increased c-fos expression was found in the lateral entorhinal cortex (LEC; a major hippocampal afferent) during OCR relative to control conditions. In a subsequent experiment it was demonstrated that rats with lesions of LEC were unable to recognize object-context associations yet showed normal object recognition and normal context recognition. These data suggest that contextual features of the environment are integrated with object identity in LEC and demonstrate that recognition of such object-context associations requires the LEC. This is consistent with the suggestion that contextual features of an event are processed in LEC and that this information is combined with spatial information from medial entorhinal cortex to form episodic memory in the hippocampus. © 2013 Wiley Periodicals, Inc. PMID:23389958

Context-dependent spatially periodic activity in the human entorhinal cortex

PubMed Central

Nguyen, T. Peter; Török, Ágoston; Shen, Jason Y.; Briggs, Deborah E.; Modur, Pradeep N.; Buchanan, Robert J.

2017-01-01

The spatially periodic activity of grid cells in the entorhinal cortex (EC) of the rodent, primate, and human provides a coordinate system that, together with the hippocampus, informs an individual of its location relative to the environment and encodes the memory of that location. Among the most defining features of grid-cell activity are the 60° rotational symmetry of grids and preservation of grid scale across environments. Grid cells, however, do display a limited degree of adaptation to environments. It remains unclear if this level of environment invariance generalizes to human grid-cell analogs, where the relative contribution of visual input to the multimodal sensory input of the EC is significantly larger than in rodents. Patients diagnosed with nontractable epilepsy who were implanted with entorhinal cortical electrodes performing virtual navigation tasks to memorized locations enabled us to investigate associations between grid-like patterns and environment. Here, we report that the activity of human entorhinal cortical neurons exhibits adaptive scaling in grid period, grid orientation, and rotational symmetry in close association with changes in environment size, shape, and visual cues, suggesting scale invariance of the frequency, rather than the wavelength, of spatially periodic activity. Our results demonstrate that neurons in the human EC represent space with an enhanced flexibility relative to neurons in rodents because they are endowed with adaptive scalability and context dependency. PMID:28396399

Entorhinal Cortex Volume in Antipsychotic-naïve Schizophrenia.

PubMed

Jose, Sam P; Sharma, Eesha; Narayanaswamy, Janardhanan C; Rajendran, Vishnurajan; Kalmady, Sunil V; Rao, Naren P; Venkatasubramanian, Ganesan; Gangadhar, Bangalore N

2012-04-01

Entorhinal cortex (ERC), a multimodal sensory relay station for the hippocampus, is critically involved in learning, emotion, and novelty detection. One of the pathogenetic mechanistic bases in schizophrenia is proposed to involve aberrant information processing in the ERC. Several studies have looked at cytoarchitectural and morphometric changes in the ERC, but results have been inconsistent possibly due to the potential confounding effects of antipsychotic treatment. In this study, we have examined the entorhinal cortex volume in antipsychotic-naïve schizophrenia patients (n=40; M:F=22:18) in comparison with age, sex, and handedness, matched (as a group) with healthy subjects (n=42; M:F=25:17) using a valid method. 3-Tesla MR images with 1-mm sections were used and the data was analyzed using the SPSS software. Female schizophrenia patients (1.25±0.22 mL) showed significant volume deficit in the right ERC in comparison with female healthy controls (1.45±0.34 mL) (F=4.9; P=0.03), after controlling for the potential confounding effects of intracranial volume. However, male patients did not differ from male controls. The left ERC volume did not differ between patients and controls. Consistent with the findings of a few earlier studies we found a reduction in the right ERC volume in patients. However, this was limited to women. Contextually, our study finding supports the role for ERC deficit in schizophrenia pathogenesis - perhaps mediated through aberrant novelty detection. Sex-differential observation of ERC volume deficit in schizophrenia needs further studies.

Lesions of the entorhinal cortex or fornix disrupt the context-dependence of fear extinction in rats.

PubMed

Ji, Jinzhao; Maren, Stephen

2008-12-12

Recent studies have shown that the hippocampus is critical for the context-dependent expression of extinguished fear memories. Here we used Pavlovian fear conditioning in rats to explore whether the entorhinal cortex and fornix, which are the major cortical and subcortical interfaces of the hippocampus, are also involved in the context-dependence of extinction. After pairing an auditory conditional stimulus (CS) with an aversive footshock (unconditional stimulus or US) in one context, rats received an extinction session in which the CS was presented without the US in another context. Conditional fear to the CS was then tested in either the extinction context or a third familiar context; freezing behavior served as the index of fear. Sham-operated rats exhibited little conditional freezing to the CS in the extinction context, but showed a robust renewal of fear when tested outside of the extinction context. In contrast, rats with neurotoxic lesions in the entorhinal cortex or electrolytic lesions in the fornix did not exhibit a renewal of fear when tested outside the extinction context. Impairments in freezing behavior to the auditory CS were not able to account for the observed results, insofar as rats with either entorhinal cortex or fornix lesions exhibited normal freezing behavior during the conditioning session. Thus, contextual memory retrieval requires not only the hippocampus proper, but also its cortical and subcortical interfaces.

Lateral entorhinal cortex is necessary for associative but not nonassociative recognition memory

PubMed Central

Wilson, David IG; Watanabe, Sakurako; Milner, Helen; Ainge, James A

2013-01-01

The lateral entorhinal cortex (LEC) provides one of the two major input pathways to the hippocampus and has been suggested to process the nonspatial contextual details of episodic memory. Combined with spatial information from the medial entorhinal cortex it is hypothesised that this contextual information is used to form an integrated spatially selective, context-specific response in the hippocampus that underlies episodic memory. Recently, we reported that the LEC is required for recognition of objects that have been experienced in a specific context (Wilson et al. (2013) Hippocampus 23:352-366). Here, we sought to extend this work to assess the role of the LEC in recognition of all associative combinations of objects, places and contexts within an episode. Unlike controls, rats with excitotoxic lesions of the LEC showed no evidence of recognizing familiar combinations of object in place, place in context, or object in place and context. However, LEC lesioned rats showed normal recognition of objects and places independently from each other (nonassociative recognition). Together with our previous findings, these data suggest that the LEC is critical for associative recognition memory and may bind together information relating to objects, places, and contexts needed for episodic memory formation. PMID:23836525

Persistent déjà vu associated with hyperperfusion in the entorhinal cortex.

PubMed

Takeda, Youji; Kurita, Tsugiko; Sakurai, Kotaro; Shiga, Tohru; Tamaki, Nagara; Koyama, Tsukasa

2011-06-01

Déjà vu is a common experience among the normal population. However, in individuals with temporal lobe epilepsy, it often occurs as a seizure manifestation. The specific cause of such déjà vu is not yet known. Here, we report a case of epilepsy with persistent déjà vu. The patient described the state as if he were living the same life he had lived before. Blood perfusion single-photon-emission computed tomography (SPECT) performed during the persistent déjà vu showed hyperperfusion in the left medial temporal area; discontinuation of déjà vu was accompanied by disappearance of the hyperperfused area on SPECT. Analysis with three-dimensional co-registration of SPECT and MRI revealed that the hyperperfused area during the persistent déjà vu was in the entorhinal cortex of the left temporal lobe. According to recent theories of recognition memory, malfunction of the parahippocampal area may cause déjà vu. It is also suggested that epileptic activity in the parahippocampal area, especially the entorhinal cortex, may elicit déjà vu. Copyright © 2011 Elsevier Inc. All rights reserved.

Grid cell hexagonal patterns formed by fast self-organized learning within entorhinal cortex.

PubMed

Mhatre, Himanshu; Gorchetchnikov, Anatoli; Grossberg, Stephen

2012-02-01

Grid cells in the dorsal segment of the medial entorhinal cortex (dMEC) show remarkable hexagonal activity patterns, at multiple spatial scales, during spatial navigation. It has previously been shown how a self-organizing map can convert firing patterns across entorhinal grid cells into hippocampal place cells that are capable of representing much larger spatial scales. Can grid cell firing fields also arise during navigation through learning within a self-organizing map? This article describes a simple and general mathematical property of the trigonometry of spatial navigation which favors hexagonal patterns. The article also develops a neural model that can learn to exploit this trigonometric relationship. This GRIDSmap self-organizing map model converts path integration signals into hexagonal grid cell patterns of multiple scales. GRIDSmap creates only grid cell firing patterns with the observed hexagonal structure, predicts how these hexagonal patterns can be learned from experience, and can process biologically plausible neural input and output signals during navigation. These results support an emerging unified computational framework based on a hierarchy of self-organizing maps for explaining how entorhinal-hippocampal interactions support spatial navigation. Copyright © 2010 Wiley Periodicals, Inc.

Processing of spatial and non-spatial information in rats with lesions of the medial and lateral entorhinal cortex: Environmental complexity matters.

PubMed

Rodo, Christophe; Sargolini, Francesca; Save, Etienne

2017-03-01

The entorhinal-hippocampal circuitry has been suggested to play an important role in episodic memory but the contribution of the entorhinal cortex remains elusive. Predominant theories propose that the medial entorhinal cortex (MEC) processes spatial information whereas the lateral entorhinal cortex (LEC) processes non spatial information. A recent study using an object exploration task has suggested that the involvement of the MEC and LEC spatial and non-spatial information processing could be modulated by the amount of information to be processed, i.e. environmental complexity. To address this hypothesis we used an object exploration task in which rats with excitotoxic lesions of the MEC and LEC had to detect spatial and non-spatial novelty among a set of objects and we varied environmental complexity by decreasing the number of objects or amount of object diversity. Reducing diversity resulted in restored ability to process spatial and non-spatial information in MEC and LEC groups, respectively. Reducing the number of objects yielded restored ability to process non-spatial information in the LEC group but not the ability to process spatial information in the MEC group. The findings indicate that the MEC and LEC are not strictly necessary for spatial and non-spatial processing but that their involvement depends on the complexity of the information to be processed. Copyright © 2016 Elsevier B.V. All rights reserved.

Reduced Spiking in Entorhinal Cortex during the Delay Period of a Cued Spatial Response Task

ERIC Educational Resources Information Center

Gupta, Kishan; Keller, Lauren A.; Hasselmo, Michael E.

2012-01-01

Intrinsic persistent spiking mechanisms in medial entorhinal cortex (mEC) neurons may play a role in active maintenance of working memory. However, electrophysiological studies of rat mEC units have primarily focused on spatial modulation. We sought evidence of differential spike rates in the mEC in rats trained on a T-maze, cued spatial delayed…

Entorhinal Cortex Volume Is Associated With Dual-Task Gait Cost Among Older Adults With MCI: Results From the Gait and Brain Study.

PubMed

Sakurai, Ryota; Bartha, Robert; Montero-Odasso, Manuel

2018-05-15

Low dual-task gait performance (the slowing of gait speed while performing a demanding cognitive task) is associated with low cognitive performance and an increased risk of progression to dementia in older adults with mild cognitive impairment. However, the reason for this remains unclear. This study aimed to examine the relationship between dual-task cost and regional brain volume, focusing on the hippocampus, parahippocampal gyrus, entorhinal cortex, and motor and lateral frontal cortices in older adults with mild cognitive impairment. Forty older adults with mild cognitive impairment from the "Gait and Brain Study" were included in this study. Gait velocity was measured during single-task (ie, walking alone) and dual-task (ie, counting backwards, subtracting serial sevens, and naming animals, in addition to walking) conditions, using an electronic walkway. Regional brain volumes were derived by automated segmentation, using 3T magnetic resonance imaging. Partial rank correlation analyses demonstrated that a smaller volume of the left entorhinal cortex was associated with higher dual-task costs in counting backwards and subtracting serial sevens conditions. Subsequent logistic regression analyses demonstrated that a smaller volume of the left entorhinal cortex was independently associated with higher dual-task cost (slowing down >20% when performing cognitive task) in these two conditions. There were no other significant associations. Our results show that lower dual-task gait performance is associated with volume reduction in the entorhinal cortex. Cognitive and motor dysfunction in older adults with mild cognitive impairment may reflect a shared pathogenic mechanism, and dual-task-related gait changes might be a surrogate motor marker for Alzheimer's disease pathology.

Functional correlates of the lateral and medial entorhinal cortex: objects, path integration and local-global reference frames.

PubMed

Knierim, James J; Neunuebel, Joshua P; Deshmukh, Sachin S

2014-02-05

The hippocampus receives its major cortical input from the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). It is commonly believed that the MEC provides spatial input to the hippocampus, whereas the LEC provides non-spatial input. We review new data which suggest that this simple dichotomy between 'where' versus 'what' needs revision. We propose a refinement of this model, which is more complex than the simple spatial-non-spatial dichotomy. MEC is proposed to be involved in path integration computations based on a global frame of reference, primarily using internally generated, self-motion cues and external input about environmental boundaries and scenes; it provides the hippocampus with a coordinate system that underlies the spatial context of an experience. LEC is proposed to process information about individual items and locations based on a local frame of reference, primarily using external sensory input; it provides the hippocampus with information about the content of an experience.

Functional correlates of the lateral and medial entorhinal cortex: objects, path integration and local–global reference frames

PubMed Central

Knierim, James J.; Neunuebel, Joshua P.; Deshmukh, Sachin S.

2014-01-01

The hippocampus receives its major cortical input from the medial entorhinal cortex (MEC) and the lateral entorhinal cortex (LEC). It is commonly believed that the MEC provides spatial input to the hippocampus, whereas the LEC provides non-spatial input. We review new data which suggest that this simple dichotomy between ‘where’ versus ‘what’ needs revision. We propose a refinement of this model, which is more complex than the simple spatial–non-spatial dichotomy. MEC is proposed to be involved in path integration computations based on a global frame of reference, primarily using internally generated, self-motion cues and external input about environmental boundaries and scenes; it provides the hippocampus with a coordinate system that underlies the spatial context of an experience. LEC is proposed to process information about individual items and locations based on a local frame of reference, primarily using external sensory input; it provides the hippocampus with information about the content of an experience. PMID:24366146

Coexistence of gamma and high-frequency oscillations in rat medial entorhinal cortex in vitro

PubMed Central

Cunningham, M O; Halliday, David M; Davies, Ceri H; Traub, Roger D; Buhl, Eberhard H; Whittington, Miles A

2004-01-01

High frequency oscillations (> 80–90 Hz) occur in neocortex and hippocampus in vivo where they are associated with specific behavioural states and more classical EEG frequency bands. In the hippocampus in vitro these oscillations can occur in the absence of pyramidal neuronal somatodendritic compartments and are temporally correlated with on-going, persistent gamma frequency oscillations. Their occurrence in the hippocampus is dependent on gap-junctional communication and it has been suggested that these high frequency oscillations originate as collective behaviour in populations of electrically coupled principal cell axonal compartments. Here we demonstrate that the superficial layers of medial entorhinal cortex can also generate high frequency oscillations associated with gamma rhythms. During persistent gamma frequency oscillations high frequency oscillations occur with a high bispectral coherence with the field gamma activity. Bursts of high frequency oscillations are temporally correlated with both the onset of compound excitatory postsynaptic potentials in fast-spiking interneurones and spikelet potentials in both pyramidal and stellate principal neurones. Both the gamma frequency and high frequency oscillations were attenuated by the gap junction blocker carbenoxolone. These data suggest that high frequency oscillations may represent the substrate for phasic drive to interneurones during persistent gamma oscillations in the medial entorhinal cortex. PMID:15254156

Multiple running speed signals in medial entorhinal cortex

PubMed Central

Hinman, James R.; Brandon, Mark P.; Climer, Jason R.; Chapman, G. William; Hasselmo, Michael E.

2016-01-01

Grid cells in medial entorhinal cortex (MEC) can be modeled using oscillatory interference or attractor dynamic mechanisms that perform path integration, a computation requiring information about running direction and speed. The two classes of computational models often use either an oscillatory frequency or a firing rate that increases as a function of running speed. Yet it is currently not known whether these are two manifestations of the same speed signal or dissociable signals with potentially different anatomical substrates. We examined coding of running speed in MEC and identified these two speed signals to be independent of each other within individual neurons. The medial septum (MS) is strongly linked to locomotor behavior and removal of MS input resulted in strengthening of the firing rate speed signal, while decreasing the strength of the oscillatory speed signal. Thus two speed signals are present in MEC that are differentially affected by disrupted MS input. PMID:27427460

Amyloid deposition in the hippocampus and entorhinal cortex: Quantitative analysis of a transgenic mouse model

PubMed Central

Reilly, John F.; Games, Dora; Rydel, Russell E.; Freedman, Stephen; Schenk, Dale; Young, Warren G.; Morrison, John H.; Bloom, Floyd E.

2003-01-01

Various transgenic mouse models of Alzheimer's disease (AD) have been developed that overexpress mutant forms of amyloid precursor protein in an effort to elucidate more fully the potential role of β-amyloid (Aβ) in the etiopathogenesis of the disease. The present study represents the first complete 3D reconstruction of Aβ in the hippocampus and entorhinal cortex of PDAPP transgenic mice. Aβ deposits were detected by immunostaining and thioflavin fluorescence, and quantified by using high-throughput digital image acquisition and analysis. Quantitative analysis of amyloid load in hippocampal subfields showed a dramatic increase between 12 and 15 months of age, with little or no earlier detectable deposition. Three-dimensional reconstruction in the oldest brains visualized previously unrecognized sheets of Aβ coursing through the hippocampus and cerebral cortex. In contrast with previous hypotheses, compact plaques form before significant deposition of diffuse Aβ, suggesting that different mechanisms are involved in the deposition of diffuse amyloid and the aggregation into plaques. The dentate gyrus was the hippocampal subfield with the greatest amyloid burden. Sublaminar distribution of Aβ in the dentate gyrus correlated most closely with the termination of afferent projections from the lateral entorhinal cortex, mirroring the selective vulnerability of this circuit in human AD. This detailed temporal and spatial analysis of Aβ and compact amyloid deposition suggests that specific corticocortical circuits express selective, but late, vulnerability to the pathognomonic markers of amyloid deposition, and can provide a basis for detecting prior vulnerability factors. PMID:12697936

The abrupt development of adult-like grid cell firing in the medial entorhinal cortex

PubMed Central

Wills, Thomas J.; Barry, Caswell; Cacucci, Francesca

2012-01-01

Understanding the development of the neural circuits subserving specific cognitive functions such as navigation remains a central problem in neuroscience. Here, we characterize the development of grid cells in the medial entorhinal cortex, which, by nature of their regularly spaced firing fields, are thought to provide a distance metric to the hippocampal neural representation of space. Grid cells emerge at the time of weaning in the rat, at around 3 weeks of age. We investigated whether grid cells in young rats are functionally equivalent to those observed in the adult as soon as they appear, or if instead they follow a gradual developmental trajectory. We find that, from the very youngest ages at which reproducible grid firing is observed (postnatal day 19): grid cells display adult-like firing fields that tessellate to form a coherent map of the local environment; that this map is universal, maintaining its internal structure across different environments; and that grid cells in young rats, as in adults, also encode a representation of direction and speed. To further investigate the developmental processes leading up to the appearance of grid cells, we present data from individual medial entorhinal cortex cells recorded across more than 1 day, spanning the period before and after the grid firing pattern emerged. We find that increasing spatial stability of firing was correlated with increasing gridness. PMID:22557949

The medial prefrontal cortex-lateral entorhinal cortex circuit is essential for episodic-like memory and associative object-recognition.

PubMed

Chao, Owen Y; Huston, Joseph P; Li, Jay-Shake; Wang, An-Li; de Souza Silva, Maria A

2016-05-01

The prefrontal cortex directly projects to the lateral entorhinal cortex (LEC), an important substrate for engaging item-associated information and relaying the information to the hippocampus. Here we ask to what extent the communication between the prefrontal cortex and LEC is critically involved in the processing of episodic-like memory. We applied a disconnection procedure to test whether the interaction between the medial prefrontal cortex (mPFC) and LEC is essential for the expression of recognition memory. It was found that male rats that received unilateral NMDA lesions of the mPFC and LEC in the same hemisphere, exhibited intact episodic-like (what-where-when) and object-recognition memories. When these lesions were placed in the opposite hemispheres (disconnection), episodic-like and associative memories for object identity, location and context were impaired. However, the disconnection did not impair the components of episodic memory, namely memory for novel object (what), object place (where) and temporal order (when), per se. Thus, the present findings suggest that the mPFC and LEC are a critical part of a neural circuit that underlies episodic-like and associative object-recognition memory. © 2015 Wiley Periodicals, Inc.

The piriform, perirhinal, and entorhinal cortex in seizure generation

PubMed Central

Vismer, Marta S.; Forcelli, Patrick A.; Skopin, Mark D.; Gale, Karen; Koubeissi, Mohamad Z.

2015-01-01

Understanding neural network behavior is essential to shed light on epileptogenesis and seizure propagation. The interconnectivity and plasticity of mammalian limbic and neocortical brain regions provide the substrate for the hypersynchrony and hyperexcitability associated with seizure activity. Recurrent unprovoked seizures are the hallmark of epilepsy, and limbic epilepsy is the most common type of medically-intractable focal epilepsy in adolescents and adults that necessitates surgical evaluation. In this review, we describe the role and relationships among the piriform (PIRC), perirhinal (PRC), and entorhinal cortex (ERC) in seizure-generation and epilepsy. The inherent function, anatomy, and histological composition of these cortical regions are discussed. In addition, the neurotransmitters, intrinsic and extrinsic connections, and the interaction of these regions are described. Furthermore, we provide evidence based on clinical research and animal models that suggest that these cortical regions may act as key seizure-trigger zones and, even, epileptogenesis. PMID:26074779

Constraints on the synchronization of entorhinal cortex stellate cells

NASA Astrophysics Data System (ADS)

Crotty, Patrick; Lasker, Eric; Cheng, Sen

2012-07-01

Synchronized oscillations of large numbers of central neurons are believed to be important for a wide variety of cognitive functions, including long-term memory recall and spatial navigation. It is therefore plausible that evolution has optimized the biophysical properties of central neurons in some way for synchronized oscillations to occur. Here, we use computational models to investigate the relationships between the presumably genetically determined parameters of stellate cells in layer II of the entorhinal cortex and the ability of coupled populations of these cells to synchronize their intrinsic oscillations: in particular, we calculate the time it takes circuits of two or three cells with initially randomly distributed phases to synchronize their oscillations to within one action potential width, and the metabolic energy they consume in doing so. For recurrent circuit topologies, we find that parameters giving low intrinsic firing frequencies close to those actually observed are strongly advantageous for both synchronization time and metabolic energy consumption.

Circumscribed malformation and nerve cell alterations in the entorhinal cortex of schizophrenics. Pathogenetic and clinical aspects.

PubMed

Jakob, H; Beckmann, H

1994-01-01

A postmortem histological comparison of 5 selected cases of schizophrenia with 5 non-schizophrenic controls showed a circumscribed malformation of the entorhinal cortex. The cortical alterations consisted mainly of a lack or a change of the characteristic island formations in layer II pre-alpha. Further, there were atypical neurons in layers II and III showing a conspicuous decrease of volume, often a change of the shape. They lay either in clusters or in columnar formations. These cells were considered "young neurons". The changes varied considerably from case to case and sometimes extended to all entorhinal layers. In one case the extension of the changes is described by means of serial sections in steps which extend over the whole rostral entorhinal region. Here, the striking architectural changes were formed in an exactly circumscribed sector and did not extend to the rostral hippocampal formation. On the whole, the changes are regarded as local migrational disturbances that occur during the second trimester of brain development. Neuronal displacements like these could give rise to various aberrant connections within the limbic system and related structures (e.g. the central position of the entorhinal region in circuits such as the entorhino-hippocampal loop, entorhinol-insula and entorhino-orbitofrontal reciprocal connections). Whereas alterations of the genetic programming of cell migrations may be suspected, various environmental influences (e.g. viral infections during the months III-V of pregnancy) appear to play a significant role. The malformations may be a decisive vulnerability factor for the later manifestation of the illness.

Synaptic Remodeling in the Dentate Gyrus, CA3, CA1, Subiculum, and Entorhinal Cortex of Mice: Effects of Deprived Rearing and Voluntary Running

PubMed Central

Schaefers, Andrea T. U.; Grafen, Keren; Teuchert-Noodt, Gertraud; Winter, York

2010-01-01

Hippocampal cell proliferation is strongly increased and synaptic turnover decreased after rearing under social and physical deprivation in gerbils (Meriones unguiculatus). We examined if a similar epigenetic effect of rearing environment on adult neuroplastic responses can be found in mice (Mus musculus). We examined synaptic turnover rates in the dentate gyrus, CA3, CA1, subiculum, and entorhinal cortex. No direct effects of deprived rearing on rates of synaptic turnover were found in any of the studied regions. However, adult wheel running had the effect of leveling layer-specific differences in synaptic remodeling in the dentate gyrus, CA3, and CA1, but not in the entorhinal cortex and subiculum of animals of both rearing treatments. Epigenetic effects during juvenile development affected adult neural plasticity in mice, but seemed to be less pronounced than in gerbils. PMID:20508828

Imidacloprid toxicity impairs spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas.

PubMed

Hsiao, Chun-Jen; Lin, Ching-Lung; Lin, Tian-Yu; Wang, Sheue-Er; Wu, Chung-Hsin

2016-04-13

It has been reported that the decimation of honey bees was because of pesticides of imidacloprid. The imidacloprid is a wildly used neonicotinoid insecticide. However, whether imidacloprid toxicity interferes with the spatial memory of echolocation bats is still unclear. Thus, we compared the spatial memory of Formosan leaf-nosed bats, Hipposideros terasensis, before and after chronic treatment with a low dose of imidacloprid. We observed that stereotyped flight patterns of echolocation bats that received chronic imidacloprid treatment were quite different from their originally learned paths. We further found that neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas of echolocation bats that received imidacloprid treatment was significantly enhanced in comparison with echolocation bats that received sham treatment. Thus, we suggest that imidacloprid toxicity may interfere with the spatial memory of echolocation bats through neural apoptosis in hippocampal CA1 and medial entorhinal cortex areas. The results provide direct evidence that pesticide toxicity causes a spatial memory disorder in echolocation bats. This implies that agricultural pesticides may pose severe threats to the survival of echolocation bats.

Comparison of imaging biomarkers for Alzheimer's disease: amyloid imaging with [18F]florbetapir positron emission tomography and magnetic resonance imaging voxel-based analysis for entorhinal cortex atrophy.

PubMed

Tateno, Amane; Sakayori, Takeshi; Kawashima, Yoshitaka; Higuchi, Makoto; Suhara, Tetsuya; Mizumura, Sunao; Mintun, Mark A; Skovronsky, Daniel M; Honjo, Kazuyoshi; Ishihara, Keiichi; Kumita, Shinichiro; Suzuki, Hidenori; Okubo, Yoshiro

2015-05-01

We compared amyloid positron emission tomography (PET) and magnetic resonance imaging (MRI) in subjects clinically diagnosed with Alzheimer's disease (AD), mild cognitive impairment (MCI), and older healthy controls (OHC) in order to test how these imaging biomarkers represent cognitive decline in AD. Fifteen OHC, 19 patients with MCI, and 19 patients with AD were examined by [(18)F]florbetapir PET to quantify the standard uptake value ratio (SUVR) as the degree of amyloid accumulation, by MRI and the voxel-based specific regional analysis system for AD to calculate z-score as the degree of entorhinal cortex atrophy, and by mini-mental state examination (MMSE) and Alzheimer's Disease Assessment Scale-cognitive component--Japanese version (ADAS-Jcog) for cognitive functions. Both cutoff values for measuring AD-like levels of amyloid (1.099 for SUVR) and entorhinal cortex atrophy (1.60 for z-score) were well differentially diagnosed and clinically defined AD from OHC (84.2% for SUVR and 86.7% for z-score). Subgroup analysis based on beta-amyloid positivity revealed that z-score significantly correlated with MMSE (r = -0.626, p < 0.01) and ADAS-Jcog (r = 0.691, p < 0.01) only among subjects with beta-amyloid. This is the first study to compare [(18)F]florbetapir PET and MRI voxel-based analysis of entorhinal cortex atrophy for AD. Both [(18)F]florbetapir PET and MRI detected changes in AD compared with OHC. Considering that entorhinal cortex atrophy correlated well with cognitive decline only among subjects with beta-amyloid, [18F]florbetapir PET makes it possible to detect AD pathology in the early stage, whereas MRI morphometry for subjects with beta-amyloid provides a good biomarker to assess the severity of AD in the later stage. Copyright © 2014 John Wiley & Sons, Ltd.

Kindling alters entorhinal cortex-hippocampal interaction by increased efficacy of presynaptic GABA(B) autoreceptors in layer III of the entorhinal cortex.

PubMed

Gloveli, Tengis; Behr, Joachim; Dugladze, Tamar; Kokaia, Zaal; Kokaia, Merab; Heinemann, Uwe

2003-08-01

We studied the effect of kindling, a model of temporal lobe epilepsy, on the frequency-dependent information transfer from the entorhinal cortex to the hippocampus in vitro. In control rats repetitive synaptic activation of layer III projection cells resulted in a frequency dependent depression of the synaptic transfer of action potentials to the hippocampus. One-to-two-days after kindling this effect was strongly reduced. Although no substantial change in synaptic inhibition upon single electrical stimulation was detected in kindled rats, there was a significant depression in the prolonged inhibition following high frequency stimulation. In kindled animals, paired-pulse depression (PPD) of stimulus-evoked IPSCs in layer III neurons was significantly stronger than in control rats. The increase of PPD is most likely caused by an increased presynaptic GABA(B) receptor-mediated autoinhibition. In kindled animals activation of presynaptic GABA(B) receptors by baclofen (10 microM) suppressed monosynaptic IPSCs significantly more than in control rats. In contrast, activation of postsynaptic GABA(B) receptors by baclofen was accompanied by comparable changes of the membrane conductance in both animal groups. Thus, in kindled animals activation of the layer III-CA1 pathway is facilitated by an increased GABA(B) receptor-mediated autoinhibition leading to an enhanced activation of the monosynaptic EC-CA1 pathway.

Optical coherence tomography visualizes neurons in human entorhinal cortex

PubMed Central

Magnain, Caroline; Augustinack, Jean C.; Konukoglu, Ender; Frosch, Matthew P.; Sakadžić, Sava; Varjabedian, Ani; Garcia, Nathalie; Wedeen, Van J.; Boas, David A.; Fischl, Bruce

2015-01-01

Abstract. The cytoarchitecture of the human brain is of great interest in diverse fields: neuroanatomy, neurology, neuroscience, and neuropathology. Traditional histology is a method that has been historically used to assess cell and fiber content in the ex vivo human brain. However, this technique suffers from significant distortions. We used a previously demonstrated optical coherence microscopy technique to image individual neurons in several square millimeters of en-face tissue blocks from layer II of the human entorhinal cortex, over 50  μm in depth. The same slices were then sectioned and stained for Nissl substance. We registered the optical coherence tomography (OCT) images with the corresponding Nissl stained slices using a nonlinear transformation. The neurons were then segmented in both images and we quantified the overlap. We show that OCT images contain information about neurons that is comparable to what can be obtained from Nissl staining, and thus can be used to assess the cytoarchitecture of the ex vivo human brain with minimal distortion. With the future integration of a vibratome into the OCT imaging rig, this technique can be scaled up to obtain undistorted volumetric data of centimeter cube tissue blocks in the near term, and entire human hemispheres in the future. PMID:25741528

A phase code for memory could arise from circuit mechanisms in entorhinal cortex

PubMed Central

Hasselmo, Michael E.; Brandon, Mark P.; Yoshida, Motoharu; Giocomo, Lisa M.; Heys, James G.; Fransen, Erik; Newman, Ehren L.; Zilli, Eric A.

2009-01-01

Neurophysiological data reveals intrinsic cellular properties that suggest how entorhinal cortical neurons could code memory by the phase of their firing. Potential cellular mechanisms for this phase coding in models of entorhinal function are reviewed. This mechanism for phase coding provides a substrate for modeling the responses of entorhinal grid cells, as well as the replay of neural spiking activity during waking and sleep. Efforts to implement these abstract models in more detailed biophysical compartmental simulations raise specific issues that could be addressed in larger scale population models incorporating mechanisms of inhibition. PMID:19656654

Control of clustered action potential firing in a mathematical model of entorhinal cortex stellate cells.

PubMed

Tait, Luke; Wedgwood, Kyle; Tsaneva-Atanasova, Krasimira; Brown, Jon T; Goodfellow, Marc

2018-07-14

The entorhinal cortex is a crucial component of our memory and spatial navigation systems and is one of the first areas to be affected in dementias featuring tau pathology, such as Alzheimer's disease and frontotemporal dementia. Electrophysiological recordings from principle cells of medial entorhinal cortex (layer II stellate cells, mEC-SCs) demonstrate a number of key identifying properties including subthreshold oscillations in the theta (4-12 Hz) range and clustered action potential firing. These single cell properties are correlated with network activity such as grid firing and coupling between theta and gamma rhythms, suggesting they are important for spatial memory. As such, experimental models of dementia have revealed disruption of organised dorsoventral gradients in clustered action potential firing. To better understand the mechanisms underpinning these different dynamics, we study a conductance based model of mEC-SCs. We demonstrate that the model, driven by extrinsic noise, can capture quantitative differences in clustered action potential firing patterns recorded from experimental models of tau pathology and healthy animals. The differential equation formulation of our model allows us to perform numerical bifurcation analyses in order to uncover the dynamic mechanisms underlying these patterns. We show that clustered dynamics can be understood as subcritical Hopf/homoclinic bursting in a fast-slow system where the slow sub-system is governed by activation of the persistent sodium current and inactivation of the slow A-type potassium current. In the full system, we demonstrate that clustered firing arises via flip bifurcations as conductance parameters are varied. Our model analyses confirm the experimentally suggested hypothesis that the breakdown of clustered dynamics in disease occurs via increases in AHP conductance. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Entorhinal volume, aerobic fitness, and recognition memory in healthy young adults: A voxel-based morphometry study.

PubMed

Whiteman, Andrew S; Young, Daniel E; Budson, Andrew E; Stern, Chantal E; Schon, Karin

2016-02-01

Converging evidence supports the hypothesis effects of aerobic exercise and environmental enrichment are beneficial for cognition, in particular for hippocampus-supported learning and memory. Recent work in humans suggests that exercise training induces changes in hippocampal volume, but it is not known if aerobic exercise and fitness also impact the entorhinal cortex. In animal models, aerobic exercise increases expression of growth factors, including brain derived neurotrophic factor (BDNF). This exercise-enhanced expression of growth hormones may boost synaptic plasticity, and neuronal survival and differentiation, potentially supporting function and structure in brain areas including but not limited to the hippocampus. Here, using voxel based morphometry and a standard graded treadmill test to determine cardio-respiratory fitness (Bruce protocol; ·VO2 max), we examined if entorhinal and hippocampal volumes were associated with cardio-respiratory fitness in healthy young adults (N=33). In addition, we examined if volumes were modulated by recognition memory performance and by serum BDNF, a putative marker of synaptic plasticity. Our results show a positive association between volume in right entorhinal cortex and cardio-respiratory fitness. In addition, average gray matter volume in the entorhinal cortex, bilaterally, was positively associated with memory performance. These data extend prior work on the cerebral effects of aerobic exercise and fitness to the entorhinal cortex in healthy young adults thus providing compelling evidence for a relationship between aerobic fitness and structure of the medial temporal lobe memory system. Copyright © 2015 Elsevier Inc. All rights reserved.

Contribution of Ih to the relative facilitation of synaptic responses induced by carbachol in the entorhinal cortex during repetitive stimulation of the parasubiculum.

PubMed

Sparks, D W; Chapman, C A

2014-10-10

Neurons in the superficial layers of the entorhinal cortex provide the hippocampus with the majority of its cortical sensory input, and also receive the major output projection from the parasubiculum. This puts the parasubiculum in a position to modulate the activity of entorhinal neurons that project to the hippocampus. These brain areas receive cholinergic projections that are active during periods of theta- and gamma-frequency electroencephalographic (EEG) activity. The purpose of this study was to investigate how cholinergic receptor activation affects the strength of repetitive synaptic responses at these frequencies in the parasubiculo-entorhinal pathway and the cellular mechanisms involved. Whole-cell patch-clamp recordings of rat layer II medial entorhinal neurons were conducted using an acute slice preparation, and responses to 5-pulse trains of stimulation at theta- and gamma-frequency delivered to the parasubiculum were recorded. The cholinergic agonist carbachol (CCh) suppressed the amplitude of single synaptic responses, but also produced a relative facilitation of synaptic responses evoked during stimulation trains. The N-methyl-d-aspartate (NMDA) glutamate receptor blocker APV did not significantly reduce the relative facilitation effect. However, the hyperpolarization-activated cationic current (Ih) channel blocker ZD7288 mimicked the relative facilitation induced by CCh, suggesting that CCh-induced inhibition of Ih could produce the effect by increasing dendritic input resistance (Rin). Inward-rectifying and leak K(+) currents are known to interact with Ih to affect synaptic excitability. Application of the K(+) channel antagonist Ba(2+) depolarized neurons and enhanced temporal summation, but did not block further facilitation of train-evoked responses by ZD7288. The Ih-dependent facilitation of synaptic responses can therefore occur during reductions in inward-rectifying potassium current (IKir) associated with dendritic depolarization. Thus, in

Healthy versus Entorhinal Cortical Atrophy Identification in Asymptomatic APOE4 Carriers at Risk for Alzheimer's Disease.

PubMed

Konishi, Kyoko; Joober, Ridha; Poirier, Judes; MacDonald, Kathleen; Chakravarty, Mallar; Patel, Raihaan; Breitner, John; Bohbot, Véronique D

2018-01-01

Early detection of Alzheimer's disease (AD) has been challenging as current biomarkers are invasive and costly. Strong predictors of future AD diagnosis include lower volume of the hippocampus and entorhinal cortex, as well as the ɛ4 allele of the Apolipoprotein E gene (APOE) gene. Therefore, studying functions that are critically mediated by the hippocampus and entorhinal cortex, such as spatial memory, in APOE ɛ4 allele carriers, may be key to the identification of individuals at risk of AD, prior to the manifestation of cognitive impairments. Using a virtual navigation task developed in-house, specifically designed to assess spatial versus non-spatial strategies, the current study is the first to differentiate functional and structural differences within APOE ɛ4 allele carriers. APOE ɛ4 allele carriers that predominantly use non-spatial strategies have decreased fMRI activity in the hippocampus and increased atrophy in the hippocampus, entorhinal cortex, and fimbria compared to APOE ɛ4 allele carriers who use spatial strategies. In contrast, APOE ɛ4 allele carriers who use spatial strategies have grey matter levels comparable to non-APOE ɛ4 allele carriers. Furthermore, in a leave-one-out analysis, grey matter in the entorhinal cortex could predict navigational strategy with 92% accuracy.

Synaptic activation patterns of the perirhinal-entorhinal inter-connections.

PubMed

de Villers-Sidani, E; Tahvildari, B; Alonso, A

2004-01-01

Ample neuropsychological evidence supports the role of rhinal cortices in memory. The perirhinal cortex (PRC) represents one of the main conduits for the bi-directional flow of information between the entorhinal-hippocampal network and the cortical mantle, a process essential in memory formation. However, despite anatomical evidence for a robust reciprocal connectivity between the perirhinal and entorhinal cortices, neurophysiological understanding of this circuitry is lacking. We now present the results of a series of electrophysiological experiments in rats that demonstrate robust synaptic activation patterns of the perirhinal-entorhinal inter-connections. First, using silicon multi-electrode arrays placed under visual guidance in vivo we performed current source density (CSD) analysis of lateral entorhinal cortex (LEC) responses to PRC stimulation, which demonstrated a current sink in layers II-III of the LEC with a latency consistent with monosynaptic activation. To further substantiate and extend this conclusion, we developed a PRC-LEC slice preparation where CSD analysis also revealed a current sink in superficial LEC layers in response to PRC stimulation. Importantly, intracellular recording of superficial LEC layer neurons confirmed that they receive a major monosynaptic excitatory input from the PRC. Finally, CSD analysis of the LEC to PRC projection in vivo also allowed us to document robust feedback synaptic activation of PRC neurons to deep LEC layer activation. We conclude that a clear bidirectional pattern of synaptic interactions exists between the PRC and LEC that would support a dynamic flow of information subserving memory function in the temporal lobe.

Healthy versus Entorhinal Cortical Atrophy Identification in Asymptomatic APOE4 Carriers at Risk for Alzheimer’s Disease

PubMed Central

Konishi, Kyoko; Joober, Ridha; Poirier, Judes; MacDonald, Kathleen; Chakravarty, Mallar; Patel, Raihaan; Breitner, John; Bohbot, Véronique D.

2018-01-01

Early detection of Alzheimer’s disease (AD) has been challenging as current biomarkers are invasive and costly. Strong predictors of future AD diagnosis include lower volume of the hippocampus and entorhinal cortex, as well as the ɛ4 allele of the Apolipoprotein E gene (APOE) gene. Therefore, studying functions that are critically mediated by the hippocampus and entorhinal cortex, such as spatial memory, in APOE ɛ4 allele carriers, may be key to the identification of individuals at risk of AD, prior to the manifestation of cognitive impairments. Using a virtual navigation task developed in-house, specifically designed to assess spatial versus non-spatial strategies, the current study is the first to differentiate functional and structural differences within APOE ɛ4 allele carriers. APOE ɛ4 allele carriers that predominantly use non-spatial strategies have decreased fMRI activity in the hippocampus and increased atrophy in the hippocampus, entorhinal cortex, and fimbria compared to APOE ɛ4 allele carriers who use spatial strategies. In contrast, APOE ɛ4 allele carriers who use spatial strategies have grey matter levels comparable to non-APOE ɛ4 allele carriers. Furthermore, in a leave-one-out analysis, grey matter in the entorhinal cortex could predict navigational strategy with 92% accuracy. PMID:29278888

Entorhinal-Hippocampal Neuronal Circuits Bridge Temporally Discontiguous Events

ERIC Educational Resources Information Center

Kitamura, Takashi; Macdonald, Christopher J.; Tonegawa, Susumu

2015-01-01

The entorhinal cortex (EC)-hippocampal (HPC) network plays an essential role for episodic memory, which preserves spatial and temporal information about the occurrence of past events. Although there has been significant progress toward understanding the neural circuits underlying the spatial dimension of episodic memory, the relevant circuits…

A map of abstract relational knowledge in the human hippocampal-entorhinal cortex.

PubMed

Garvert, Mona M; Dolan, Raymond J; Behrens, Timothy Ej

2017-04-27

The hippocampal-entorhinal system encodes a map of space that guides spatial navigation. Goal-directed behaviour outside of spatial navigation similarly requires a representation of abstract forms of relational knowledge. This information relies on the same neural system, but it is not known whether the organisational principles governing continuous maps may extend to the implicit encoding of discrete, non-spatial graphs. Here, we show that the human hippocampal-entorhinal system can represent relationships between objects using a metric that depends on associative strength. We reconstruct a map-like knowledge structure directly from a hippocampal-entorhinal functional magnetic resonance imaging adaptation signal in a situation where relationships are non-spatial rather than spatial, discrete rather than continuous, and unavailable to conscious awareness. Notably, the measure that best predicted a behavioural signature of implicit knowledge and blood oxygen level-dependent adaptation was a weighted sum of future states, akin to the successor representation that has been proposed to account for place and grid-cell firing patterns.

Preserved number of entorhinal cortex layer II neurons in aged macaque monkeys

NASA Technical Reports Server (NTRS)

Gazzaley, A. H.; Thakker, M. M.; Hof, P. R.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

1997-01-01

The perforant path, which consists of the projection from the layer II neurons of the entorhinal cortex to the outer molecular layer of the dentate gyrus, is a critical circuit involved in learning and memory formation. Accordingly, disturbances in this circuit may contribute to age-related cognitive deficits. In a previous study, we demonstrated a decrease in N-methyl-D-aspartate receptor subunit 1 immunofluorescence intensity in the outer molecular layer of aged macaque monkeys. In this study, we used the optical fractionator, a stereological method, to determine if a loss of layer II neurons occurred in the same animals in which the N-methyl-D-aspartate receptor subunit 1 alteration was observed. Our results revealed no significant differences in the number of layer II neurons between juvenile, young adult, and aged macaque monkeys. These results suggest that the circuit-specific decrease in N-methyl-D-aspartate receptor subunit 1 reported previously occurs in the absence of structural compromise of the perforant path, and thus may be linked to an age-related change in the physiological properties of this circuit.

A map of abstract relational knowledge in the human hippocampal–entorhinal cortex

PubMed Central

Garvert, Mona M; Dolan, Raymond J; Behrens, Timothy EJ

2017-01-01

The hippocampal–entorhinal system encodes a map of space that guides spatial navigation. Goal-directed behaviour outside of spatial navigation similarly requires a representation of abstract forms of relational knowledge. This information relies on the same neural system, but it is not known whether the organisational principles governing continuous maps may extend to the implicit encoding of discrete, non-spatial graphs. Here, we show that the human hippocampal–entorhinal system can represent relationships between objects using a metric that depends on associative strength. We reconstruct a map-like knowledge structure directly from a hippocampal–entorhinal functional magnetic resonance imaging adaptation signal in a situation where relationships are non-spatial rather than spatial, discrete rather than continuous, and unavailable to conscious awareness. Notably, the measure that best predicted a behavioural signature of implicit knowledge and blood oxygen level-dependent adaptation was a weighted sum of future states, akin to the successor representation that has been proposed to account for place and grid-cell firing patterns. DOI: http://dx.doi.org/10.7554/eLife.17086.001 PMID:28448253

Entorhinal Tau Pathology, Episodic Memory Decline, and Neurodegeneration in Aging.

PubMed

Maass, Anne; Lockhart, Samuel N; Harrison, Theresa M; Bell, Rachel K; Mellinger, Taylor; Swinnerton, Kaitlin; Baker, Suzanne L; Rabinovici, Gil D; Jagust, William J

2018-01-17

The medial temporal lobe (MTL) is an early site of tau accumulation and MTL dysfunction may underlie episodic-memory decline in aging and dementia. Postmortem data indicate that tau pathology in the transentorhinal cortex is common by age 60, whereas spread to neocortical regions and worsening of cognition is associated with β-amyloid (Aβ). We used [ 18 F]AV-1451 and [ 11 C]PiB positron emission tomography, structural MRI, and neuropsychological assessment to investigate how in vivo tau accumulation in temporal lobe regions, Aβ, and MTL atrophy contribute to episodic memory in cognitively normal older adults ( n = 83; age, 77 ± 6 years; 58% female). Stepwise regressions identified tau in MTL regions known to be affected in old age as the best predictor of episodic-memory performance independent of Aβ status. There was no interactive effect of MTL tau with Aβ on memory. Higher MTL tau was related to higher age in the subjects without evidence of Aβ. Among temporal lobe subregions, episodic memory was most strongly related to tau-tracer uptake in the parahippocampal gyrus, particularly the posterior entorhinal cortex, which in our parcellation includes the transentorhinal cortex. In subjects with longitudinal MRI and cognitive data ( n = 57), entorhinal atrophy mirrored patterns of tau pathology and their relationship with memory decline. Our data are consistent with neuropathological studies and further suggest that entorhinal tau pathology underlies memory decline in old age even without Aβ. SIGNIFICANCE STATEMENT Tau tangles and β-amyloid (Aβ) plaques are key lesions in Alzheimer's disease (AD) but both pathologies also occur in cognitively normal older people. Neuropathological data indicate that tau tangles in the medial temporal lobe (MTL) underlie episodic-memory impairments in AD dementia. However, it remains unclear whether MTL tau pathology also accounts for memory impairments often seen in elderly people and how Aβ affects this relationship

Depression of neuronal excitability and epileptic activities by group II metabotropic glutamate receptors in the medial entorhinal cortex.

PubMed

Zhang, Haopeng; Cilz, Nicholas I; Yang, Chuanxiu; Hu, Binqi; Dong, Hailong; Lei, Saobo

2015-11-01

Whereas the ionotropic glutamate receptors are the major mediator in glutamatergic transmission, the metabotropic glutamate receptors (mGluRs) usually play a modulatory role. Whereas the entorhinal cortex (EC) is an essential structure involved in the generation and propagation of epilepsy, the roles and mechanisms of mGluRs in epilepsy in the EC have not been determined. Here, we studied the effects of activation of group II metabotropic glutamate receptors (mGluRs II) on epileptiform activity induced by picrotoxin or deprivation of extracellular Mg2+ and neuronal excitability in the medial EC. We found that activation of mGluRs II by application of the selective agonist, LY354740, exerted robust inhibition on epileptiform activity. LY354740 hyperpolarized entorhinal neurons via activation of a K+ conductance and inhibition of a Na+ -permeable channel. LY354740-induced hyperpolarization was G protein-dependent, but independent of adenylyl cyclase and protein kinase A. However, the function of Gβγ was involved in mGluRs II-mediated depression of both neuronal excitability and epileptiform activity. Our results provide a novel cellular mechanism to explain the antiepileptic effects of mGluRs II in the treatment of epilepsy. © 2015 Wiley Periodicals, Inc.

The perforant path projection to hippocampal area CA1 in the rat hippocampal-entorhinal cortex combined slice.

PubMed

Empson, R M; Heinemann, U

1995-05-01

1. The perforant path projection from layer III of the entorhinal cortex to CA1 of the hippocampus was studied within a hippocampal-entorhinal combined slice preparation. We prevented contamination from the other main hippocampal pathways by removal of CA3 and the dentate gyrus. 2. Initially the projection was mapped using field potential recordings that suggested an excitatory sink in stratum lacunosum moleculare with an associated source in stratum pyramidale. 3. However, recording intracellularly from CA1 cells, stimulation of the perforant path produced prominent fast GABAA and slow GABAB IPSPs often preceded by small EPSPs. In a small number of cells we observed EPSPs only. 4. CNQX blocked excitatory and inhibitory responses. This indicated the presence of an intervening excitatory synapse between the inhibitory interneurone and the pyramidal cell. 5. Focal bicuculline applications revealed that the major site of GABAA inhibitory input was to stratum radiatum of CA1. 6. The inhibition activated by the perforant path was very effective at reducing simultaneously activated Schaffer collateral mediated EPSPs and suprathreshold-stimulated action potentials. 7. Blockade of fast inhibition increased excitability and enhanced slow inhibition. Both increases relied upon the activation of NMDA receptors. 8. Perforant path inputs activated prominent and effective disynaptic inhibition of CA1 cells. This has significance for the output of hippocampal processing during normal behaviour and also under pathological conditions.

Propagation of cortical spreading depression into the hippocampus: The role of the entorhinal cortex.

PubMed

Martens-Mantai, Tanja; Speckmann, Erwin-Josef; Gorji, Ali

2014-07-22

Propagation of cortical spreading depression (CSD) to the subcortical structures could be the underlying mechanism of some neurological deficits in migraine with aura. The entorhinal cortex (EC) as a gray matter bridge between the neocortex and subcortical regions plays an important role in this propagation. In vitro combined neocortex-hippocampus brain slices were used to study the propagation pattern of CSD between the neocortex and the hippocampus. The effects of different compounds as well as tetanic electrical stimulations in the EC on propagation of CSD to the hippocampus were investigated. Repetitive induction of CSD by KCl injection in the somatosensory cortex enhanced the probability of CSD entrance to the hippocampus via EC. Local application of AMPA receptor blocker CNQX and cannabinoid receptor agonist WIN 55212-2 in EC facilitated the propagation of CSD to the hippocampus, whereas application of NMDA receptor blocker APV and GABA A receptor blocker bicuculline in this region reduced the probability of CSD penetration to the hippocampus. Application of tetanic stimulation in EC also facilitated the propagation of CSD entrance to the hippocampus. Our data suggest the importance of synaptic plasticity of EC in filtering the propagation of CSD into subcortical structures and possibly the occurrence of concomitant neurological deficits. Synapse, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

Lesions of entorhinal cortex produce a calpain-mediated degradation of brain spectrin in dentate gyrus. I. Biochemical studies.

PubMed

Seubert, P; Ivy, G; Larson, J; Lee, J; Shahi, K; Baudry, M; Lynch, G

1988-09-06

Lesions of the rat entorhinal cortex cause extensive synaptic restructuring and perturbation of calcium regulation in the dentate gyrus of hippocampus. Calpain is a calcium-activated protease which has been implicated in degenerative phenomena in muscles and in peripheral nerves. In addition, calpain degrades several major structural neuronal proteins and has been proposed to play a critical role in the morphological changes observed following deafferentation. In this report we present evidence that lesions of the entorhinal cortex produce a marked increase in the breakdown of brain spectrin, a substrate for calpain, in the dentate gyrus. Two lines of evidence indicate that this effect is due to calpain activation: (i) the spectrin breakdown products observed following the lesion are indistinguishable from calpain-generated spectrin fragments in vitro; and (ii) their appearance can be reduced by prior intraventricular in fusion of leupeptin, a calpain inhibitor. Levels of spectrin breakdown products are increased as early as 4 h post-lesion, reach maximal values at 2 days, and remain above normal to some degree for at least 27 days. In addition, a small but significant increase in spectrin proteolysis is also observed in the hippocampus contralateral to the lesioned side in the first week postlesion. At 2 days postlesion the total spectrin immunoreactivity (native polypeptide plus breakdown products) increases by 40%, suggesting that denervation of the dentate gyrus produces not only an increased rate of spectrin degradation but also an increased rate of spectrin synthesis. These results indicate that calpain activation and spectrin degradation are early biochemical events following deafferentation and might well participate in the remodelling of postsynaptic structures. Finally, the magnitude of the observed effects as well as the stable nature of the breakdown products provide a sensitive assay for neuronal pathology.

APOE associated hemispheric asymmetry of entorhinal cortical thickness in aging and Alzheimer’s disease

PubMed Central

Donix, Markus; Burggren, Alison C.; Scharf, Maria; Marschner, Kira; Suthana, Nanthia A.; Siddarth, Prabha; Krupa, Allison K.; Jones, Michael; Martin-Harris, Laurel; Ercoli, Linda M.; Miller, Karen J.; Werner, Annett; von Kummer, Rüdiger; Sauer, Cathrin; Small, Gary W.; Holthoff, Vjera A.; Bookheimer, Susan Y.

2013-01-01

Across species structural and functional hemispheric asymmetry is a fundamental feature of the brain. Environmental and genetic factors determine this asymmetry during brain development and modulate its interaction with brain disorders. The e4 allele of the apolipoprotein E gene (APOE-4) is a risk factor for Alzheimer’s disease, associated with regionally specific effects on brain morphology and function during the life span. Furthermore, entorhinal and hippocampal hemispheric asymmetry could be modified by pathology during Alzheimer’s disease development. Using high-resolution magnetic resonance imaging and a cortical unfolding technique we investigated whether carrying the APOE-4 allele influences hemispheric asymmetry in the entorhinal cortex and the hippocampus among patients with Alzheimer’s disease as well as in middle-aged and older cognitively healthy individuals. APOE-4 carriers showed a thinner entorhinal cortex in the left hemisphere when compared with the right hemisphere across all participants. Non-carriers of the allele showed this asymmetry only in the patient group. Cortical thickness in the hippocampus did not vary between hemispheres among APOE-4 allele carriers and non-carriers. The APOE-4 allele modulates hemispheric asymmetry in entorhinal cortical thickness. Among Alzheimer’s disease patients, this asymmetry might be less dependent on the APOE genotype and a more general marker of incipient disease pathology. PMID:24080518

Phasic and tonic neuron ensemble codes for stimulus-environment conjunctions in the lateral entorhinal cortex.

PubMed

Pilkiw, Maryna; Insel, Nathan; Cui, Younghua; Finney, Caitlin; Morrissey, Mark D; Takehara-Nishiuchi, Kaori

2017-07-06

The lateral entorhinal cortex (LEC) is thought to bind sensory events with the environment where they took place. To compare the relative influence of transient events and temporally stable environmental stimuli on the firing of LEC cells, we recorded neuron spiking patterns in the region during blocks of a trace eyeblink conditioning paradigm performed in two environments and with different conditioning stimuli. Firing rates of some neurons were phasically selective for conditioned stimuli in a way that depended on which room the rat was in; nearly all neurons were tonically selective for environments in a way that depended on which stimuli had been presented in those environments. As rats moved from one environment to another, tonic neuron ensemble activity exhibited prospective information about the conditioned stimulus associated with the environment. Thus, the LEC formed phasic and tonic codes for event-environment associations, thereby accurately differentiating multiple experiences with overlapping features.

Intrinsic electrophysiological properties of entorhinal cortex stellate cells and their contribution to grid cell firing fields

PubMed Central

Pastoll, Hugh; Ramsden, Helen L.; Nolan, Matthew F.

2012-01-01

The medial entorhinal cortex (MEC) is an increasingly important focus for investigation of mechanisms for spatial representation. Grid cells found in layer II of the MEC are likely to be stellate cells, which form a major projection to the dentate gyrus. Entorhinal stellate cells are distinguished by distinct intrinsic electrophysiological properties, but how these properties contribute to representation of space is not yet clear. Here, we review the ionic conductances, synaptic, and excitable properties of stellate cells, and examine their implications for models of grid firing fields. We discuss why existing data are inconsistent with models of grid fields that require stellate cells to generate periodic oscillations. An alternative possibility is that the intrinsic electrophysiological properties of stellate cells are tuned specifically to control integration of synaptic input. We highlight recent evidence that the dorsal-ventral organization of synaptic integration by stellate cells, through differences in currents mediated by HCN and leak potassium channels, influences the corresponding organization of grid fields. Because accurate cellular data will be important for distinguishing mechanisms for generation of grid fields, we introduce new data comparing properties measured with whole-cell and perforated patch-clamp recordings. We find that clustered patterns of action potential firing and the action potential after-hyperpolarization (AHP) are particularly sensitive to recording condition. Nevertheless, with both methods, these properties, resting membrane properties and resonance follow a dorsal-ventral organization. Further investigation of the molecular basis for synaptic integration by stellate cells will be important for understanding mechanisms for generation of grid fields. PMID:22536175

Rebound spiking in layer II medial entorhinal cortex stellate cells: Possible mechanism of grid cell function

PubMed Central

Shay, Christopher F.; Ferrante, Michele; Chapman, G. William; Hasselmo, Michael E.

2015-01-01

Rebound spiking properties of medial entorhinal cortex (mEC) stellate cells induced by inhibition may underlie their functional properties in awake behaving rats, including the temporal phase separation of distinct grid cells and differences in grid cell firing properties. We investigated rebound spiking properties using whole cell patch recording in entorhinal slices, holding cells near spiking threshold and delivering sinusoidal inputs, superimposed with realistic inhibitory synaptic inputs to test the capacity of cells to selectively respond to specific phases of inhibitory input. Stellate cells showed a specific phase range of hyperpolarizing inputs that elicited spiking, but non-stellate cells did not show phase specificity. In both cell types, the phase range of spiking output occurred between the peak and subsequent descending zero crossing of the sinusoid. The phases of inhibitory inputs that induced spikes shifted earlier as the baseline sinusoid frequency increased, while spiking output shifted to later phases. Increases in magnitude of the inhibitory inputs shifted the spiking output to earlier phases. Pharmacological blockade of h-current abolished the phase selectivity of hyperpolarizing inputs eliciting spikes. A network computational model using cells possessing similar rebound properties as found in vitro produces spatially periodic firing properties resembling grid cell firing when a simulated animal moves along a linear track. These results suggest that the ability of mEC stellate cells to fire rebound spikes in response to a specific range of phases of inhibition could support complex attractor dynamics that provide completion and separation to maintain spiking activity of specific grid cell populations. PMID:26385258

The Human Periallocortex: Layer Pattern in Presubiculum, Parasubiculum and Entorhinal Cortex. A Review

PubMed Central

Insausti, Ricardo; Muñoz-López, Mónica; Insausti, Ana M.; Artacho-Pérula, Emilio

2017-01-01

The cortical mantle is not homogeneous, so that three types of cortex can be distinguished: allocortex, periallocortex and isocortex. The main distinction among those three types is based on morphological differences, in particular the number of layers, overall organization, appearance, etc., as well as its connectivity. Additionally, in the phylogenetic scale, this classification is conserved among different mammals. The most primitive and simple cortex is the allocortex, which is characterized by the presence of three layers, with one cellular main layer; it is continued by the periallocortex, which presents six layers, although with enough differences in the layer pattern to separate three different fields: presubiculum (PrS), parasubiculum (PaS), and entorhinal cortex (EC). The closest part to the allocortex (represented by the subiculum) is the PrS, which shows outer (layers I–III) and inner (V–VI) principal layers (lamina principalis externa and lamina principalis interna), both separated by a cell poor band, parallel to the pial surface (layer IV or lamina dissecans). This layer organization is present throughout the anterior-posterior axis. The PaS continues the PrS, but its rostrocaudal extent is shorter than the PrS. The organization of the PaS shows the layer pattern more clearly than in the PrS. Up to six layers are recognizable in the PaS, with layer IV as lamina dissecans between superficial (layers I–III) and deep (V–VI) layers, as in the PrS. The EC presents even more clearly the layer pattern along both mediolateral and rostrocaudal extent. The layer pattern is a thick layer I, layer II in islands, layer III medium pyramids, layer IV as lamina dissecans (not present throughout the EC extent), layer V with dark and big pyramids and a multiform layer VI. The EC borders laterally the proisocortex (incomplete type of isocortex). Variations in the appearance of its layers justify the distinction of subfields in the EC, in particular in human and

The Human Periallocortex: Layer Pattern in Presubiculum, Parasubiculum and Entorhinal Cortex. A Review.

PubMed

Insausti, Ricardo; Muñoz-López, Mónica; Insausti, Ana M; Artacho-Pérula, Emilio

2017-01-01

The cortical mantle is not homogeneous, so that three types of cortex can be distinguished: allocortex, periallocortex and isocortex. The main distinction among those three types is based on morphological differences, in particular the number of layers, overall organization, appearance, etc., as well as its connectivity. Additionally, in the phylogenetic scale, this classification is conserved among different mammals. The most primitive and simple cortex is the allocortex, which is characterized by the presence of three layers, with one cellular main layer; it is continued by the periallocortex, which presents six layers, although with enough differences in the layer pattern to separate three different fields: presubiculum (PrS), parasubiculum (PaS), and entorhinal cortex (EC). The closest part to the allocortex (represented by the subiculum) is the PrS, which shows outer (layers I-III) and inner (V-VI) principal layers ( lamina principalis externa and lamina principalis interna ), both separated by a cell poor band, parallel to the pial surface (layer IV or lamina dissecans ). This layer organization is present throughout the anterior-posterior axis. The PaS continues the PrS, but its rostrocaudal extent is shorter than the PrS. The organization of the PaS shows the layer pattern more clearly than in the PrS. Up to six layers are recognizable in the PaS, with layer IV as lamina dissecans between superficial (layers I-III) and deep (V-VI) layers, as in the PrS. The EC presents even more clearly the layer pattern along both mediolateral and rostrocaudal extent. The layer pattern is a thick layer I, layer II in islands, layer III medium pyramids, layer IV as lamina dissecans (not present throughout the EC extent), layer V with dark and big pyramids and a multiform layer VI. The EC borders laterally the proisocortex (incomplete type of isocortex). Variations in the appearance of its layers justify the distinction of subfields in the EC, in particular in human and

Phasic and tonic neuron ensemble codes for stimulus-environment conjunctions in the lateral entorhinal cortex

PubMed Central

Pilkiw, Maryna; Insel, Nathan; Cui, Younghua; Finney, Caitlin; Morrissey, Mark D; Takehara-Nishiuchi, Kaori

2017-01-01

The lateral entorhinal cortex (LEC) is thought to bind sensory events with the environment where they took place. To compare the relative influence of transient events and temporally stable environmental stimuli on the firing of LEC cells, we recorded neuron spiking patterns in the region during blocks of a trace eyeblink conditioning paradigm performed in two environments and with different conditioning stimuli. Firing rates of some neurons were phasically selective for conditioned stimuli in a way that depended on which room the rat was in; nearly all neurons were tonically selective for environments in a way that depended on which stimuli had been presented in those environments. As rats moved from one environment to another, tonic neuron ensemble activity exhibited prospective information about the conditioned stimulus associated with the environment. Thus, the LEC formed phasic and tonic codes for event-environment associations, thereby accurately differentiating multiple experiences with overlapping features. DOI: http://dx.doi.org/10.7554/eLife.28611.001 PMID:28682237

Retrograde and anterograde memory following selective damage to the dorsolateral entorhinal cortex.

PubMed

Gervais, Nicole J; Barrett-Bernstein, Meagan; Sutherland, Robert J; Mumby, Dave G

2014-12-01

Anatomical and electrophysiological evidence suggest the dorsolateral entorhinal cortex (DLEC) is involved in processing spatial information, but there is currently no consensus on whether its functions are necessary for normal spatial learning and memory. The present study examined the effects of excitotoxic lesions of the DLEC on retrograde and anterograde memory on two tests of allocentric spatial learning: a hidden fixed-platform watermaze task, and a novelty-preference-based dry-maze test. Deficits were observed on both tests when training occurred prior to but not following n-methyl d-aspartate (NMDA) lesions of DLEC, suggesting retrograde memory impairment in the absence of anterograde impairments for the same information. The retrograde memory impairments were temporally-graded; rats that received DLEC lesions 1-3 days following training displayed deficits, while those that received lesions 7-10 days following training performed like a control group that received sham surgery. The deficits were not attenuated by co-infusion of tetrodotoxin, suggesting they are not due to disruption of neural processing in structures efferent to the DLEC, such as the hippocampus. The present findings provide evidence that the DLEC is involved in the consolidation of allocentric spatial information. Copyright © 2014 Elsevier Inc. All rights reserved.

The entorhinal cortex of the Megachiroptera: a comparative study of Wahlberg's epauletted fruit bat and the straw-coloured fruit bat.

PubMed

Gatome, Catherine W; Slomianka, Lutz; Mwangi, Dieter K; Lipp, Hans-Peter; Amrein, Irmgard

2010-05-01

This study describes the organisation of the entorhinal cortex of the Megachiroptera, straw-coloured fruit bat and Wahlberg's epauletted fruit bat. Using Nissl and Timm stains, parvalbumin and SMI-32 immunohistochemistry, we identified five fields within the medial (MEA) and lateral (LEA) entorhinal areas. MEA fields E(CL) and E(C) are characterised by a poor differentiation between layers II and III, a distinct layer IV and broad, stratified layers V and VI. LEA fields E(I), E(R) and E(L) are distinguished by cell clusters in layer II, a clear differentiation between layers II and III, a wide columnar layer III and a broad sublayer Va. Clustering in LEA layer II was more typical of the straw-coloured fruit bat. Timm-staining was most intense in layers Ib and II across all fields and layer III of field E(R). Parvalbumin-like staining varied along a medio-lateral gradient with highest immunoreactivity in layers II and III of MEA and more lateral fields of LEA. Sparse SMI-32-like immunoreactivity was seen only in Wahlberg's epauletted fruit bat. Of the neurons in MEA layer II, ovoid stellate cells account for approximately 38%, polygonal stellate cells for approximately 8%, pyramidal cells for approximately 18%, oblique pyramidal cells for approximately 6% and other neurons of variable morphology for approximately 29%. Differences between bats and other species in cellular make-up and cytoarchitecture of layer II may relate to their three-dimensional habitat. Cytoarchitecture of layer V in conjunction with high encephalisation and structural changes in the hippocampus suggest similarities in efferent hippocampal --> entorhinal --> cortical interactions between fruit bats and primates.

Morphological characterization of rat entorhinal neurons in vivo: soma-dendritic structure and axonal domains.

PubMed

Lingenhöhl, K; Finch, D M

1991-01-01

We used in vivo intracellular labeling with horseradish peroxidase in order to study the soma-dendritic morphology and axonal projections of rat entorhinal neurons. The cells responded to hippocampal stimulation with inhibitory postsynaptic potentials, and thus likely received direct or indirect hippocampal input. All cells (n = 24) showed extensive dendritic domains that extended in some cases for more than 1 mm. The dendrites of layer II neurons were largely restricted to layers I and II or layers I-III, while the dendrites of deeper cells could extend through all cortical layers. Computed 3D rotations showed that the basilar dendrites of deep pyramids extended roughly parallel to the cortical layering, and that they were mostly confined to the layer containing the soma and layers immediately adjacent. Total dendritic lengths averaged 9.8 mm +/- 3.8 (SD), and ranged from 5 mm to more than 18 mm. Axonal processes could be visualized in 21 cells. Most of these showed axonal branching within the entorhinal cortex, sometimes extensive. Efferent axonal domains were reconstructed in detail in 3 layer II stellate cells. All 3 projected axons across the subicular complex to the dentate gyrus. One of these cells showed an extensive net-like axonal domain that also projected to several other structures, including the hippocampus proper, subicular complex, and the amygdalo-piriform transition area. The axons of layer III and IV cells projected to the angular bundle, where they continued in a rostral direction. In contrast to the layer II, III and IV cells, no efferent axonal branches leaving the entorhinal cortex could be visualized in 5 layer V neurons. The data indicate that entorhinal neurons can integrate input from a considerable volume of entorhinal cortex by virtue of their extensive dendritic domains, and provide a further basis for specifying the layers in which cells receive synaptic input. The extensive axonal branching pattern seen in most of the cells would

Laminar activity in the hippocampus and entorhinal cortex related to novelty and episodic encoding

PubMed Central

Maass, Anne; Schütze, Hartmut; Speck, Oliver; Yonelinas, Andrew; Tempelmann, Claus; Heinze, Hans-Jochen; Berron, David; Cardenas-Blanco, Arturo; Brodersen, Kay H.; Enno Stephan, Klaas; Düzel, Emrah

2014-01-01

The ability to form long-term memories for novel events depends on information processing within the hippocampus (HC) and entorhinal cortex (EC). The HC–EC circuitry shows a quantitative segregation of anatomical directionality into different neuronal layers. Whereas superficial EC layers mainly project to dentate gyrus (DG), CA3 and apical CA1 layers, HC output is primarily sent from pyramidal CA1 layers and subiculum to deep EC layers. Here we utilize this directionality information by measuring encoding activity within HC/EC subregions with 7 T high resolution functional magnetic resonance imaging (fMRI). Multivariate Bayes decoding within HC/EC subregions shows that processing of novel information most strongly engages the input structures (superficial EC and DG/CA2–3), whereas subsequent memory is more dependent on activation of output regions (deep EC and pyramidal CA1). This suggests that while novelty processing is strongly related to HC–EC input pathways, the memory fate of a novel stimulus depends more on HC–EC output. PMID:25424131

A distinct entorhinal cortex to hippocampal CA1 direct circuit for olfactory associative learning.

PubMed

Li, Yiding; Xu, Jiamin; Liu, Yafeng; Zhu, Jia; Liu, Nan; Zeng, Wenbo; Huang, Ning; Rasch, Malte J; Jiang, Haifei; Gu, Xiang; Li, Xiang; Luo, Minhua; Li, Chengyu; Teng, Junlin; Chen, Jianguo; Zeng, Shaoqun; Lin, Longnian; Zhang, Xiaohui

2017-04-01

Lateral and medial parts of entorhinal cortex (EC) convey nonspatial 'what' and spatial 'where' information, respectively, into hippocampal CA1, via both the indirect EC layer 2→ hippocampal dentate gyrus→CA3→CA1 and the direct EC layer 3→CA1 paths. However, it remains elusive how the direct path transfers distinct information and contributes to hippocampal learning functions. Here we report that lateral EC projection neurons selectively form direct excitatory synapses onto a subpopulation of morphologically complex, calbindin-expressing pyramidal cells (PCs) in the dorsal CA1 (dCA1), while medial EC neurons uniformly innervate all dCA1 PCs. Optogenetically inactivating the distinct lateral EC-dCA1 connections or the postsynaptic dCA1 calbindin-expressing PC activity slows olfactory associative learning. Moreover, optetrode recordings reveal that dCA1 calbindin-expressing PCs develop more selective spiking responses to odor cues during learning. Thus, our results identify a direct lateral EC→dCA1 circuit that is required for olfactory associative learning.

Does the entorhinal cortex use the Fourier transform?

PubMed Central

Orchard, Jeff; Yang, Hao; Ji, Xiang

2013-01-01

Some neurons in the entorhinal cortex (EC) fire bursts when the animal occupies locations organized in a hexagonal grid pattern in their spatial environment. Place cells have also been observed, firing bursts only when the animal occupies a particular region of the environment. Both of these types of cells exhibit theta-cycle modulation, firing bursts in the 4–12 Hz range. Grid cells fire bursts of action potentials that precess with respect to the theta cycle, a phenomenon dubbed “theta precession.” Various models have been proposed to explain these phenomena, and how they relate to navigation. Among the most promising are the oscillator interference models. The bank-of-oscillators model proposed by Welday et al. (2011) exhibits all these features. However, their simulations are based on theoretical oscillators, and not implemented entirely with spiking neurons. We extend their work in a number of ways. First, we place the oscillators in a frequency domain and reformulate the model in terms of Fourier theory. Second, this perspective suggests a division of labor for implementing spatial maps: position vs. map layout. The animal's position is encoded in the phases of the oscillators, while the spatial map shape is encoded implicitly in the weights of the connections between the oscillators and the read-out nodes. Third, it reveals that the oscillator phases all need to conform to a linear relationship across the frequency domain. Fourth, we implement a partial model of the EC using spiking leaky integrate-and-fire (LIF) neurons. Fifth, we devise new coupling mechanisms, enlightened by the global phase constraint, and show they are capable of keeping spiking neural oscillators in consistent formation. Our model demonstrates place cells, grid cells, and phase precession. The Fourier model also gives direction for future investigations, such as integrating sensory feedback to combat drift, or explaining why grid cells exist at all. PMID:24376415

Anatomical and Electrophysiological Clustering of Superficial Medial Entorhinal Cortex Interneurons

PubMed Central

2017-01-01

Abstract Local GABAergic interneurons regulate the activity of spatially-modulated principal cells in the medial entorhinal cortex (MEC), mediating stellate-to-stellate connectivity and possibly enabling grid formation via recurrent inhibitory circuitry. Despite the important role interneurons seem to play in the MEC cortical circuit, the combination of low cell counts and functional diversity has made systematic electrophysiological studies of these neurons difficult. For these reasons, there remains a paucity of knowledge on the electrophysiological profiles of superficial MEC interneuron populations. Taking advantage of glutamic acid decarboxylase 2 (GAD2)-IRES-tdTomato and PV-tdTomato transgenic mice, we targeted GABAergic interneurons for whole-cell patch-clamp recordings and characterized their passive membrane features, basic input/output properties and action potential (AP) shape. These electrophysiologically characterized cells were then anatomically reconstructed, with emphasis on axonal projections and pial depth. K-means clustering of interneuron anatomical and electrophysiological data optimally classified a population of 106 interneurons into four distinct clusters. The first cluster is comprised of layer 2- and 3-projecting, slow-firing interneurons. The second cluster is comprised largely of PV+ fast-firing interneurons that project mainly to layers 2 and 3. The third cluster contains layer 1- and 2-projecting interneurons, and the fourth cluster is made up of layer 1-projecting horizontal interneurons. These results, among others, will provide greater understanding of the electrophysiological characteristics of MEC interneurons, help guide future in vivo studies, and may aid in uncovering the mechanism of grid field formation. PMID:29085901

Parvalbumin interneuron mediated feedforward inhibition controls signal output in the deep layers of the perirhinal‐entorhinal cortex

PubMed Central

Willems, Janske G. P.; Wadman, Wytse J.

2018-01-01

Abstract The perirhinal (PER) and lateral entorhinal (LEC) cortex form an anatomical link between the neocortex and the hippocampus. However, neocortical activity is transmitted through the PER and LEC to the hippocampus with a low probability, suggesting the involvement of the inhibitory network. This study explored the role of interneuron mediated inhibition, activated by electrical stimulation in the agranular insular cortex (AiP), in the deep layers of the PER and LEC. Activated synaptic input by AiP stimulation rarely evoked action potentials in the PER‐LEC deep layer excitatory principal neurons, most probably because the evoked synaptic response consisted of a small excitatory and large inhibitory conductance. Furthermore, parvalbumin positive (PV) interneurons—a subset of interneurons projecting onto the axo‐somatic region of principal neurons—received synaptic input earlier than principal neurons, suggesting recruitment of feedforward inhibition. This synaptic input in PV interneurons evoked varying trains of action potentials, explaining the fast rising, long lasting synaptic inhibition received by deep layer principal neurons. Altogether, the excitatory input from the AiP onto deep layer principal neurons is overruled by strong feedforward inhibition. PV interneurons, with their fast, extensive stimulus‐evoked firing, are able to deliver this fast evoked inhibition in principal neurons. This indicates an essential role for PV interneurons in the gating mechanism of the PER‐LEC network. PMID:29341361

Effect of prenatal protein malnutrition on long-term potentiation and BDNF protein expression in the rat entorhinal cortex after neocortical and hippocampal tetanization.

PubMed

Hernández, Alejandro; Burgos, Héctor; Mondaca, Mauricio; Barra, Rafael; Núñez, Héctor; Pérez, Hernán; Soto-Moyano, Rubén; Sierralta, Walter; Fernández, Victor; Olivares, Ricardo; Valladares, Luis

2008-01-01

Reduction of the protein content from 25 to 8% casein in the diet of pregnant rats results in impaired neocortical long-term potentiation (LTP) of the offspring together with lower visuospatial memory performance. The present study was aimed to investigate whether this type of maternal malnutrition could result in modification of plastic capabilities of the entorhinal cortex (EC) in the adult progeny. Unlike normal eutrophic controls, 55-60-day-old prenatally malnourished rats were unable to develop LTP in the medial EC to tetanizing stimulation delivered to either the ipsilateral occipital cortex or the CA1 hippocampal region. Tetanizing stimulation of CA1 also failed to increase the concentration of brain-derived neurotrophic factor (BDNF) in the EC of malnourished rats. Impaired capacity of the EC of prenatally malnourished rats to develop LTP and to increase BDNF levels during adulthood may be an important factor contributing to deficits in learning performance having adult prenatally malnourished animals.

Effect of Prenatal Protein Malnutrition on Long-Term Potentiation and BDNF Protein Expression in the Rat Entorhinal Cortex after Neocortical and Hippocampal Tetanization

PubMed Central

Hernández, Alejandro; Burgos, Héctor; Mondaca, Mauricio; Barra, Rafael; Núñez, Héctor; Pérez, Hernán; Soto-Moyano, Rubén; Sierralta, Walter; Fernández, Victor; Olivares, Ricardo; Valladares, Luis

2008-01-01

Reduction of the protein content from 25 to 8% casein in the diet of pregnant rats results in impaired neocortical long-term potentiation (LTP) of the offspring together with lower visuospatial memory performance. The present study was aimed to investigate whether this type of maternal malnutrition could result in modification of plastic capabilities of the entorhinal cortex (EC) in the adult progeny. Unlike normal eutrophic controls, 55–60-day-old prenatally malnourished rats were unable to develop LTP in the medial EC to tetanizing stimulation delivered to either the ipsilateral occipital cortex or the CA1 hippocampal region. Tetanizing stimulation of CA1 also failed to increase the concentration of brain-derived neurotrophic factor (BDNF) in the EC of malnourished rats. Impaired capacity of the EC of prenatally malnourished rats to develop LTP and to increase BDNF levels during adulthood may be an important factor contributing to deficits in learning performance having adult prenatally malnourished animals. PMID:18604298

Felbamate but not phenytoin or gabapentin reduces glutamate release by blocking presynaptic NMDA receptors in the entorhinal cortex

PubMed Central

Yang, Jian; Wetterstrand, Caroline; Jones, Roland S.G.

2007-01-01

Summary We have shown that a number of anticonvulsant drugs can reduce glutamate release at synapses in the rat entorhinal cortex (EC) in vitro. We have also shown that presynaptic NMDA receptors (NMDAr) tonically facilitate glutamate release at these synapses. In the present study we determined whether, phenytoin, gabapentin and felbamate may reduce glutamate release by blocking the presynaptic NMDAr. Whole cell patch clamp recordings of spontaneous excitatory postsynaptic currents (sEPSCs) were used as a monitor of presynaptic glutamate release. Postsynaptic NMDAr were blocked with internal dialysis with an NMDAr channel blocker. The antagonist, 2-AP5, reduced the frequency of sEPSCs by blocking the presynaptic facilitatory NMDAr, but did not occlude a reduction in sEPSC frequency by gabapentin or phenytoin. Felbamate also reduced sEPSC frequency, but this effect was occluded by prior application of 2-AP5. Thus, whilst all three drugs can reduce glutamate release, only the action of felbamate seems to be due to interaction with presynaptic NMDAr. PMID:17980555

Grid cell mechanisms and function: Contributions of entorhinal persistent spiking and phase resetting

PubMed Central

Hasselmo, Michael E.

2008-01-01

This article presents a model of grid cell firing based on the intrinsic persistent firing shown experimentally in neurons of entorhinal cortex. In this model, the mechanism of persistent firing allows individual neurons to hold a stable baseline firing frequency. Depolarizing input from speed modulated head direction cells transiently shifts the frequency of firing from baseline, resulting in a shift in spiking phase in proportion to the integral of velocity. The convergence of input from different persistent firing neurons causes spiking in a grid cell only when the persistent firing neurons are within similar phase ranges. This model effectively simulates the two-dimensional firing of grid cells in open field environments, as well as the properties of theta phase precession. This model provides an alternate implementation of oscillatory interference models. The persistent firing could also interact on a circuit level with rhythmic inhibition and neurons showing membrane potential oscillations to code position with spiking phase. These mechanisms could operate in parallel with computation of position from visual angle and distance of stimuli. In addition to simulating two-dimensional grid patterns, models of phase interference can account for context-dependent firing in other tasks. In network simulations of entorhinal cortex, hippocampus and postsubiculum, the reset of phase effectively replicates context-dependent firing by entorhinal and hippocampal neurons during performance of a continuous spatial alternation task, a delayed spatial alternation task with running in a wheel during the delay period, and a hairpin maze task. PMID:19021258

Abnormalities in the fatty acid composition of the postmortem entorhinal cortex of patients with schizophrenia, bipolar disorder, and major depressive disorder.

PubMed

Hamazaki, Kei; Hamazaki, Tomohito; Inadera, Hidekuni

2013-11-30

Previous studies of postmortem orbitofrontal cortex have shown abnormalities in levels of n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA), in individuals with schizophrenia, bipolar disorder, and major depressive disorder (MDD). We have previously measured PUFA levels in the postmortem hippocampus from patients with schizophrenia or bipolar disorder and control subjects; however, we found no significant differences between the groups except for small changes in n-6 PUFAs. Furthermore, our study of the postmortem amygdala showed no significant differences in major PUFAs in individuals with schizophrenia, bipolar disorder, or MDD in comparison with controls. In the present study, we investigated whether there were any changes in PUFAs in the entorhinal cortexes of patients with schizophrenia (n=15), bipolar disorder (n=15), or MDD (n=15) compared with unaffected controls (n=15) matched for characteristics including age and sex. In contrast to previous studies of the orbitofrontal cortex and hippocampus, we found no significant differences in major PUFAs. However, we found a 34.3% decrease in docosapentaenoic acid (DPA) (22:5n-3) in patients with MDD and an 8.7% decrease in docosatetraenoic acid (22:4n-6) in those with schizophrenia, compared with controls. Changes in PUFAs in patients with these psychiatric disorders may be specific to certain brain regions. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

GABAergic Projections from the Medial Septum Selectively Inhibit Interneurons in the Medial Entorhinal Cortex

PubMed Central

Gonzalez-Sulser, Alfredo; Parthier, Daniel; Candela, Antonio; McClure, Christina; Pastoll, Hugh; Garden, Derek; Sürmeli, Gülşen

2014-01-01

The medial septum (MS) is required for theta rhythmic oscillations and grid cell firing in the medial entorhinal cortex (MEC). While GABAergic, glutamatergic, and cholinergic neurons project from the MS to the MEC, their synaptic targets are unknown. To investigate whether MS neurons innervate specific layers and cell types in the MEC, we expressed channelrhodopsin-2 in mouse MS neurons and used patch-clamp recording in brain slices to determine the response to light activation of identified cells in the MEC. Following activation of MS axons, we observed fast monosynaptic GABAergic IPSPs in the majority (>60%) of fast-spiking (FS) and low-threshold-spiking (LTS) interneurons in all layers of the MEC, but in only 1.5% of nonstellate principal cells (NSPCs) and in no stellate cells. We also observed fast glutamatergic responses to MS activation in a minority (<5%) of NSPCs, FS, and LTS interneurons. During stimulation of MS inputs at theta frequency (10 Hz), the amplitude of GABAergic IPSPs was maintained, and spike output from LTS and FS interneurons was entrained at low (25–60 Hz) and high (60–180 Hz) gamma frequencies, respectively. By demonstrating cell type-specific targeting of the GABAergic projection from the MS to the MEC, our results support the idea that the MS controls theta frequency activity in the MEC through coordination of inhibitory circuits. PMID:25505326

Low cortical iron and high entorhinal cortex volume promote cognitive functioning in the oldest-old.

PubMed

van Bergen, Jiri M G; Li, Xu; Quevenco, Frances C; Gietl, Anton F; Treyer, Valerie; Leh, Sandra E; Meyer, Rafael; Buck, Alfred; Kaufmann, Philipp A; Nitsch, Roger M; van Zijl, Peter C M; Hock, Christoph; Unschuld, Paul G

2018-04-01

The aging brain is characterized by an increased presence of neurodegenerative and vascular pathologies. However, there is substantial variation regarding the relationship between an individual's pathological burden and resulting cognitive impairment. To identify correlates of preserved cognitive functioning at highest age, the relationship between β-amyloid plaque load, presence of small vessel cerebrovascular disease (SVCD), iron-burden, and brain atrophy was investigated. Eighty cognitively unimpaired participants (44 oldest-old, aged 85-96 years; 36 younger-old, aged 55-80 years) were scanned by integrated positron emission tomography-magnetic resonance imaging for assessing beta regional amyloid plaque load (18F-flutemetamol), white matter hyperintensities as an indicator of SVCD (fluid-attenuated inversion recovery-magnetic resonance imaging), and iron load (quantitative susceptibility mapping). For the oldest-old group, lower cortical volume, increased β-amyloid plaque load, prevalence of SVCD, and lower cognitive performance in the normal range were found. However, compared to normal-old, cortical iron burden was lower in the oldest-old. Moreover, only in the oldest-old, entorhinal cortex volume positively correlated with β-amyloid plaque load. Our data thus indicate that the co-occurrence of aging-associated neuropathologies with reduced quantitative susceptibility mapping measures of cortical iron load constitutes a lower vulnerability to cognitive loss. Copyright © 2017 Elsevier Inc. All rights reserved.

Grid and non-grid cells in medial entorhinal cortex represent spatial location and environmental features with complementary coding schemes

PubMed Central

Diehl, Geoffrey W.; Hon, Olivia J.; Leutgeb, Stefan; Leutgeb, Jill K.

2017-01-01

Summary The medial entorhinal cortex (mEC) has been identified as a hub for spatial information processing by the discovery of grid, border, and head-direction cells. Here we find that in addition to these well characterized classes, nearly all of the remaining two thirds of mEC cells can be categorized as spatially selective. We refer to these cells as non-grid spatial cells and confirmed that their spatial firing patterns were unrelated to running speed and highly reproducible within the same environment. However, in response to manipulations of environmental features, such as box shape or box color, non-grid spatial cells completely reorganized their spatial firing patterns. At the same time, grid cells retained their spatial alignment and predominantly responded with redistributed firing rates across their grid fields. Thus, mEC contains a joint representation of both spatial and environmental feature content, with specialized cell types showing different types of integrated coding of multimodal information. PMID:28343867

Feedforward inhibition regulates perirhinal transmission of neocortical inputs to the entorhinal cortex: ultrastructural study in guinea pigs.

PubMed

Pinto, Aline; Fuentes, Cesar; Paré, Denis

2006-04-20

The rhinal cortices constitute the main route for impulse traffic to and from the hippocampus. Tracing studies have revealed that the perirhinal cortex forms strong reciprocal connections with the neo- and entorhinal cortex (EC). However, physiological investigations indicate that perirhinal transmission of neocortical and EC inputs occurs with a low probability. In search of an explanation for these contradictory findings, we have analyzed synaptic connections in this network by combining injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHAL) into the neocortex, area 36, or area 35 with gamma-aminobutyric acid (GABA) immunocytochemistry and electron microscopic observations. Within area 36, neocortical axon terminals formed only asymmetric synapses, usually with GABA-negative spines (87%), and less frequently with GABA-immunopositive (GABA+) dendrites (13%). A similar synaptic distribution was observed within area 35 except that asymmetric synapses onto GABA+ dendrites were more frequent (23% of synapses). Examination of the projections from area 36 to area 35 and from both regions to the EC revealed an even higher incidence of asymmetric synapses onto GABA+ dendrites (35 and 32%, respectively) than what was observed in the neocortical projection to areas 36 and 35. Furthermore, some of the neocortical and perirhinal terminals containing PHAL and GABA immunolabeling formed symmetric synapses onto GABA-negative dendrites in their projection sites (neocortex to area 35, 16%; area 36 to 35, 7%; areas 36-35 to EC, 12%). Taken together, these findings suggest that impulse transmission through the rhinal circuit is subjected to strong inhibitory influences, reconciling anatomical and physiological data about this network.

FEEDFORWARD INHIBITION REGULATES PERIRHINAL TRANSMISSION OF NEOCORTICAL INPUTS TO THE ENTORHINAL CORTEX: ULTRASTRUCTURAL STUDY IN GUINEA PIGS

PubMed Central

Pinto, Aline; Fuentes, Cesar; Paré, Denis

2008-01-01

The rhinal cortices constitute the main route for impulse traffic to and from the hippocampus. Tracing studies have revealed that the perirhinal cortex forms strong reciprocal connections with the neo- and entorhinal cortex (EC). Yet, physiological investigations indicate that perirhinal transmission of neocortical and EC inputs occurs with a low probability. In search of an explanation for these contradictory findings, we have analyzed synaptic connections in this network by combining injections of the anterograde tracer Phaseolus vulgaris-leucoagglutinin (PHAL) into the neocortex, area 36, or area 35 with GABA immunocytochemistry and electron microscopic observations. Within area 36, neocortical axon terminals formed only asymmetric synapses, usually with GABA negative spines (87%), and less frequently with GABA immunopositive (GABA+) dendrites (13%). A similar synaptic distribution was observed within area 35 except that asymmetric synapses onto GABA+ dendrites were more frequent (23% of synapses). Examination of the projections from area 36 to area 35 and from both regions to the EC revealed an even higher incidence of asymmetric synapses onto GABA+ dendrites (35% and 32% respectively) than what was observed in the neocortical projection to areas 36 and 35. Furthermore, a proportion of neocortical and perirhinal terminals containing PHAL and GABA immunolabeling formed symmetric synapses onto GABA negative dendrites in their projection sites (neocortex to area 35, 16%; area 36 to 35, 7%; areas 36–35 to EC, 12%). Taken together, these findings suggest that impulse transmission through the rhinal circuit is subjected to strong inhibitory influences, reconciling anatomical and physiological data about this network. PMID:16506192

Reduced Mitochondrial Activity is Early and Steady in the Entorhinal Cortex but it is Mainly Unmodified in the Frontal Cortex in Alzheimer's Disease.

PubMed

Armand-Ugon, Mercedes; Ansoleaga, Belen; Berjaoui, Sara; Ferrer, Isidro

2017-01-01

It is well established that mitochondrial damage plays a role in the pathophysiology of Alzheimer's disease (AD). However, studies carried out in humans barely contemplate regional differences with disease progression. To study the expression of selected nuclear genes encoding subunits of the mitochondrial complexes and the activity of mitochondrial complexes in AD, in two regions: the entorhinal cortex (EC) and frontal cortex area 8 (FC). Frozen samples from 148 cases processed for gene expression by qRT-PCR and determination of individual activities of mitochondrial complexes I, II, IV and V using commercial kits and home-made assays. Decreased expression of NDUFA2, NDUFB3, UQCR11, COX7C, ATPD, ATP5L and ATP50, covering subunits of complex I, II, IV and V, occurs in total homogenates of the EC in AD stages V-VI when compared with stages I-II. However reduced activity of complexes I, II and V of isolated mitochondria occurs as early as stages I-II when compared with middle-aged individuals in the EC. In contrast, no alterations in the expression of the same genes and no alterations in the activity of mitochondrial complexes are found in the FC in the same series. Different mechanisms of impaired energy metabolism may occur in AD, one of them, represented by the EC, is the result of primary and early alteration of mitochondria; the other one is probably the result, at least in part, of decreased functional input and is represented by hypometabolism in the FC in AD patients aged 86 or younger. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Electrical Stimulation in Hippocampus and Entorhinal Cortex Impairs Spatial and Temporal Memory.

PubMed

Goyal, Abhinav; Miller, Jonathan; Watrous, Andrew J; Lee, Sang Ah; Coffey, Tom; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn A; Inman, Cory; Sheth, Sameer A; Wanda, Paul A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Jacobs, Joshua

2018-05-09

The medial temporal lobe (MTL) is widely implicated in supporting episodic memory and navigation, but its precise functional role in organizing memory across time and space remains elusive. Here we examine the specific cognitive processes implemented by MTL structures (hippocampus and entorhinal cortex) to organize memory by using electrical brain stimulation, leveraging its ability to establish causal links between brain regions and features of behavior. We studied neurosurgical patients of both sexes who performed spatial-navigation and verbal-episodic memory tasks while brain stimulation was applied in various regions during learning. During the verbal memory task, stimulation in the MTL disrupted the temporal organization of encoded memories such that items learned with stimulation tended to be recalled in a more randomized order. During the spatial task, MTL stimulation impaired subjects' abilities to remember items located far away from boundaries. These stimulation effects were specific to the MTL. Our findings thus provide the first causal demonstration in humans of the specific memory processes that are performed by the MTL to encode when and where events occurred. SIGNIFICANCE STATEMENT Numerous studies have implicated the medial temporal lobe (MTL) in encoding spatial and temporal memories, but they have not been able to causally demonstrate the nature of the cognitive processes by which this occurs in real-time. Electrical brain stimulation is able to demonstrate causal links between a brain region and a given function with high temporal precision. By examining behavior in a memory task as subjects received MTL stimulation, we provide the first causal evidence demonstrating the role of the MTL in organizing the spatial and temporal aspects of episodic memory. Copyright © 2018 the authors 0270-6474/18/384471-11$15.00/0.

Regional Specific Evidence for Memory-Load Dependent Activity in the Dorsal Subiculum and the Lateral Entorhinal Cortex

PubMed Central

Ku, Shih-pi; Nakamura, Nozomu H.; Maingret, Nicolas; Mahnke, Liv; Yoshida, Motoharu; Sauvage, Magdalena M.

2017-01-01

The subiculum and the lateral entorhinal cortex (LEC) are the main output areas of the hippocampus which contribute to spatial and non-spatial memory. The proximal part of the subiculum (bordering CA1) receives heavy projections from the perirhinal cortex and the distal part of CA1 (bordering the subiculum), both known for their ties to object recognition memory. However, the extent to which the proximal subiculum contributes to non-spatial memory is still unclear. Comparatively, the involvement of the LEC in non-spatial information processing is quite well known. However, very few studies have investigated its role within the frame of memory function. Thus, it is not known whether its contribution depends on memory load. In addition, the deep layers of the EC have been shown to be predictive of subsequent memory performance, but not its superficial layers. Hence, here we tested the extent to which the proximal part of the subiculum and the superficial and deep layers of the LEC contribute to non-spatial memory, and whether this contribution depends on the memory load of the task. To do so, we imaged brain activity at cellular resolution in these areas in rats performing a delayed nonmatch to sample task based on odors with two different memory loads (5 or 10 odors). This imaging technique is based on the detection of the RNA of the immediate-early gene Arc, which is especially tied to synaptic plasticity and behavioral demands, and is commonly used to map activity in the medial temporal lobe. We report for the first time that the proximal part of the subiculum is recruited in a memory-load dependent manner and the deep layers of the LEC engaged under high memory load conditions during the retrieval of non-spatial memory, thus shedding light on the specific networks contributing to non-spatial memory retrieval. PMID:28790897

Regional Specific Evidence for Memory-Load Dependent Activity in the Dorsal Subiculum and the Lateral Entorhinal Cortex.

PubMed

Ku, Shih-Pi; Nakamura, Nozomu H; Maingret, Nicolas; Mahnke, Liv; Yoshida, Motoharu; Sauvage, Magdalena M

2017-01-01

The subiculum and the lateral entorhinal cortex (LEC) are the main output areas of the hippocampus which contribute to spatial and non-spatial memory. The proximal part of the subiculum (bordering CA1) receives heavy projections from the perirhinal cortex and the distal part of CA1 (bordering the subiculum), both known for their ties to object recognition memory. However, the extent to which the proximal subiculum contributes to non-spatial memory is still unclear. Comparatively, the involvement of the LEC in non-spatial information processing is quite well known. However, very few studies have investigated its role within the frame of memory function. Thus, it is not known whether its contribution depends on memory load. In addition, the deep layers of the EC have been shown to be predictive of subsequent memory performance, but not its superficial layers. Hence, here we tested the extent to which the proximal part of the subiculum and the superficial and deep layers of the LEC contribute to non-spatial memory, and whether this contribution depends on the memory load of the task. To do so, we imaged brain activity at cellular resolution in these areas in rats performing a delayed nonmatch to sample task based on odors with two different memory loads (5 or 10 odors). This imaging technique is based on the detection of the RNA of the immediate-early gene Arc , which is especially tied to synaptic plasticity and behavioral demands, and is commonly used to map activity in the medial temporal lobe. We report for the first time that the proximal part of the subiculum is recruited in a memory-load dependent manner and the deep layers of the LEC engaged under high memory load conditions during the retrieval of non-spatial memory, thus shedding light on the specific networks contributing to non-spatial memory retrieval.

Time course of the dependence of associative memory retrieval on the entorhinal cortex.

PubMed

Chen, Xi; Liao, Zhengli; Wong, Yin Ting; Guo, Yiping; He, Jufang

2014-12-01

As the gateway between the hippocampal system and the neocortex, the entorhinal cortex (EC) is hypothesized to be the hub in which the transformation of recent memory to remote memory is processed. We explored the role of the EC on the retrieval of recent and remote associative fear memory. A within-subject approach was adopted to compare the freezing rates of rats in EC intact and EC inactivated conditions following trace fear conditioning. The EC was inactivated by infusing an AMPA antagonist. The fear conditioning used a combined visual and auditory conditioned stimulus with a foot shock. On week 1 following the conditioning, the rats in the EC intact condition exhibited a freezing rate of 92.4±9.5% in response to the light stimulus compared with a 6.3±7.9% freezing rate in the EC inactivated condition. The freezing rates were 87.0±17.8% and 4.7±6.5% on week 2 in the EC intact and inactivated conditions, respectively. These results indicate that the EC participates in the retrieval of associative memory. Extinction of the fear memory was observed in the EC intact condition, as the mean freezing rate decreased to 62.7±23.0% on week 4 and 41.2±26.4% on week 5. However, the freezing rate increased to 26.8±14.2% on week 4 and 22.3±14.4% on week 5 in the EC inactivated condition. The normalized dependence of fear memory retrieval on the EC was 93.2±8.3% on week 1, and significantly decreased on weeks 4 and 5. In summary, the retrieval of associative memory depends on the EC, but this dependence decreases over time. Copyright © 2014 Elsevier Inc. All rights reserved.

Physiological roles of Kv2 channels in entorhinal cortex layer II stellate cells revealed by Guangxitoxin‐1E

PubMed Central

Hönigsperger, Christoph; Nigro, Maximiliano J.

2016-01-01

Key points Kv2 channels underlie delayed‐rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Almost nothing is known about Kv2 channel functions in medial entorhinal cortex (mEC) neurons, which are involved in representing space, memory formation, epilepsy and dementia.Stellate cells in layer II of the mEC project to the hippocampus and are considered to be space‐representing grid cells. We used the new Kv2 blocker Guangxitoxin‐1E (GTx) to study Kv2 functions in these neurons.Voltage clamp recordings from mEC stellate cells in rat brain slices showed that GTx inhibited delayed‐rectifier K+ current but not transient A‐type current.In current clamp, GTx had multiple effects: (i) increasing excitability and bursting at moderate spike rates but reducing firing at high rates; (ii) enhancing after‐depolarizations; (iii) reducing the fast and medium after‐hyperpolarizations; (iv) broadening action potentials; and (v) reducing spike clustering.GTx is a useful tool for studying Kv2 channels and their functions in neurons. Abstract The medial entorhinal cortex (mEC) is strongly involved in spatial navigation, memory, dementia and epilepsy. Although potassium channels shape neuronal activity, their roles in mEC are largely unknown. We used the new Kv2 blocker Guangxitoxin‐1E (GTx; 10–100 nm) in rat brain slices to investigate Kv2 channel functions in mEC layer II stellate cells (SCs). These neurons project to the hippocampus and are considered to be grid cells representing space. Voltage clamp recordings from SCs nucleated patches showed that GTx inhibited a delayed rectifier K+ current activating beyond –30 mV but not transient A‐type current. In current clamp, GTx (i) had almost no effect on the first action potential but markedly slowed repolarization of late spikes during repetitive firing; (ii) enhanced the after‐depolarization (ADP); (iii) reduced fast and medium after�

Entorhinal Cortical Ocean Cells Encode Specific Contexts and Drive Context-Specific Fear Memory

PubMed Central

Kitamura, Takashi; Sun, Chen; Martin, Jared; Kitch, Lacey J; Schnitzer, Mark J; Tonegawa, Susumu

2016-01-01

Summary Forming distinct representations and memories of multiple contexts and episodes is thought to be a crucial function of the hippocampal-entorhinal cortical network. The hippocampal dentate gyrus (DG) and CA3 are known to contribute to these functions but the role of the entorhinal cortex (EC) is poorly understood. Here, we show that Ocean cells, excitatory stellate neurons in the medial EC layer II projecting into DG and CA3, rapidly form a distinct representation of a novel context and drive context-specific activation of downstream CA3 cells as well as context-specific fear memory. In contrast, Island cells, excitatory pyramidal neurons in the medial EC layer II projecting into CA1, are indifferent to context-specific encoding or memory. On the other hand, Ocean cells are dispensable for temporal association learning, for which Island cells are crucial. Together, the two excitatory medial EC layer II inputs to the hippocampus have complementary roles in episodic memory. PMID:26402611

Entorhinal Principal Neurons Mediate Brain-stimulation Treatments for Epilepsy.

PubMed

Xu, Zhenghao; Wang, Yi; Chen, Bin; Xu, Cenglin; Wu, Xiaohua; Wang, Ying; Zhang, Shihong; Hu, Weiwei; Wang, Shuang; Guo, Yi; Zhang, Xiangnan; Luo, Jianhong; Duan, Shumin; Chen, Zhong

2016-12-01

Brain stimulation is an alternative treatment for epilepsy. However, the neuronal circuits underlying its mechanisms remain obscure. We found that optogenetic activation (1Hz) of entorhinal calcium/calmodulin-dependent protein kinase II α (CaMKIIα)-positive neurons, but not GABAergic neurons, retarded hippocampal epileptogenesis and reduced hippocampal seizure severity, similar to that of entorhinal low-frequency electrical stimulation (LFES). Optogenetic inhibition of entorhinal CaMKIIα-positive neurons blocked the antiepileptic effect of LFES. The channelrhodopsin-2-eYFP labeled entorhinal CaMKIIα-positive neurons primarily targeted the hippocampus, and the activation of these fibers reduced hippocampal seizure severity. By combining extracellular recording and pharmacological methods, we found that activating entorhinal CaMKIIα-positive neurons induced the GABA-mediated inhibition of hippocampal neurons. Optogenetic activation of focal hippocampal GABAergic neurons mimicked this neuronal modulatory effect and reduced hippocampal seizure severity, but the anti-epileptic effect is weaker than that of entorhinal LFES, which may be due to the limited spatial neuronal modulatory effect of focal photo-stimulation. Our results demonstrate a glutamatergic-GABAergic neuronal circuit for LFES treatment of epilepsy, which is mediated by entorhinal principal neurons. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

Inhibition of projections from the basolateral amygdala to the entorhinal cortex disrupts the acquisition of contextual fear

PubMed Central

Sparta, Dennis R.; Smithuis, Jim; Stamatakis, Alice M.; Jennings, Joshua H.; Kantak, Pranish A.; Ung, Randall L.; Stuber, Garret D.

2014-01-01

The development of excessive fear and/or stress responses to environmental cues such as contexts associated with a traumatic event is a hallmark of post-traumatic stress disorder (PTSD). The basolateral amygdala (BLA) has been implicated as a key structure mediating contextual fear conditioning. In addition, the hippocampus has an integral role in the encoding and processing of contexts associated with strong, salient stimuli such as fear. Given that both the BLA and hippocampus play an important role in the regulation of contextual fear conditioning, examining the functional connectivity between these two structures may elucidate a role for this pathway in the development of PTSD. Here, we used optogenetic strategies to demonstrate that the BLA sends a strong glutamatergic projection to the hippocampal formation through the entorhinal cortex (EC). Next, we photoinhibited glutamatergic fibers from the BLA terminating in the EC during the acquisition or expression of contextual fear conditioning. In mice that received optical inhibition of the BLA-to-EC pathway during the acquisition session, we observed a significant decrease in freezing behavior in a context re-exposure session. In contrast, we observed no differences in freezing behavior in mice that were only photoinhibited during the context re-exposure session. These data demonstrate an important role for the BLA-to-EC glutamatergic pathway in the acquisition of contextual fear conditioning. PMID:24834031

Neuroprotective effects of vinpocetine and its major metabolite cis-apovincaminic acid on NMDA-induced neurotoxicity in a rat entorhinal cortex lesion model.

PubMed

Nyakas, Csaba; Felszeghy, Klára; Szabó, Róbert; Keijser, Jan N; Luiten, Paul G M; Szombathelyi, Zsolt; Tihanyi, Károly

2009-01-01

Vinpocetine (ethyl-apovincaminate, Cavinton), a synthetic derivative of the Vinca minor alkaloid vincamine, has been used now for decades for prevention and treatment of cerebrovascular diseases predisposing to development of dementia. Both vinpocetine and its main metabolite cis-apovincaminic acid (cAVA) exert a neuroprotective type of action. Bilateral N-methyl-D-aspartate (NMDA)-induced neurodegeneration in the entorhinal cortex of rat was used as a dementia model to confirm the neuroprotective action of these compounds in vivo. NMDA-lesioned rats were treated 60 min before lesion and throughout 3 postoperative days with a 10 mg/kg intraperitoneal dose of vinpocetine or cAVA. Behavioral tests started after termination of drug treatment and consisted of novel object recognition, social discrimination, and spontaneous alternation in a Y-maze, and spatial learning in the Morris water maze. At the end of behavioral testing brains were perfused with fixative and the size of the excitotoxic neuronal lesion and that of microglial activation around the lesion were assayed quantitatively on brain sections immunostained for neuron-specific nuclear protein (NeuN) and integrin CD11b, respectively. Entorhinal NMDA lesions impaired recognition of novel objects and the new social partner, and suppressed spontaneous alternation and spatial learning performance in the Morris maze. Both vinpocetine and cAVA effectively attenuated the behavioral deficits, and significantly decreased lesion size and the region of microglia activation. Both lesion-induced attention deficit and learning disabilities were markedly alleviated by vinpocetine and cAVA. The morphological findings corroborated the behavioral observations and indicated reduced lesion size and microglia activation especially after vinpocetine treatment which supports an in vivo neuroprotective mode of action of vinpocitine and a less potent action of cAVA.

On the role of the entorhinal cortex in the effective connectivity of the hippocampal formation.

PubMed

López-Madrona, Víctor J; Matias, Fernanda S; Pereda, Ernesto; Canals, Santiago; Mirasso, Claudio R

2017-04-01

Inferring effective connectivity from neurophysiological data is a challenging task. In particular, only a finite (and usually small) number of sites are simultaneously recorded, while the response of one of these sites can be influenced by other sites that are not being recorded. In the hippocampal formation, for instance, the connections between areas CA1-CA3, the dentate gyrus (DG), and the entorhinal cortex (EC) are well established. However, little is known about the relations within the EC layers, which might strongly affect the resulting effective connectivity estimations. In this work, we build excitatory/inhibitory neuronal populations representing the four areas CA1, CA3, the DG, and the EC and fix their connectivities. We model the EC by three layers (LII, LIII, and LV) and assume any possible connection between them. Our results, based on Granger Causality (GC) and Partial Transfer Entropy (PTE) measurements, reveal that the estimation of effective connectivity in the hippocampus strongly depends on the connectivities between EC layers. Moreover, we find, for certain EC configurations, very different results when comparing GC and PTE measurements. We further demonstrate that causal links can be robustly inferred regardless of the excitatory or inhibitory nature of the connection, adding complexity to their interpretation. Overall, our work highlights the importance of a careful analysis of the connectivity methods to prevent unrealistic conclusions when only partial information about the experimental system is available, as usually happens in brain networks. Our results suggest that the combination of causality measures with neuronal modeling based on precise neuroanatomical tracing may provide a powerful framework to disambiguate causal interactions in the brain.

Histamine Enhances Theta-Coupled Spiking and Gamma Oscillations in the Medial Entorhinal Cortex Consistent With Successful Spatial Recognition.

PubMed

Chen, Quanhui; Luo, Fenlan; Yue, Faguo; Xia, Jianxia; Xiao, Qin; Liao, Xiang; Jiang, Jun; Zhang, Jun; Hu, Bo; Gao, Dong; He, Chao; Hu, Zhian

2017-06-07

Encoding of spatial information in the superficial layers of the medial entorhinal cortex (sMEC) involves theta-modulated spiking and gamma oscillations, as well as spatially tuned grid cells and border cells. Little is known about the role of the arousal-promoting histaminergic system in the modification of information encoded in the sMEC in vivo, and how such histamine-regulated information correlates with behavioral functions. Here, we show that histamine upregulates the neural excitability of a significant proportion of neurons (16.32%, 39.18%, and 52.94% at 30 μM, 300 μM, and 3 mM, respectively) and increases local theta (4-12 Hz) and gamma power (low: 25-48 Hz; high: 60-120 Hz) in the sMEC, through activation of histamine receptor types 1 and 3. During spatial exploration, the strength of theta-modulated firing of putative principal neurons and high gamma oscillations is enhanced about 2-fold by histamine. The histamine-mediated increase of theta phase-locking of spikes and high gamma power is consistent with successful spatial recognition. These results, for the first time, reveal possible mechanisms involving the arousal-promoting histaminergic system in the modulation of spatial cognition. Published by Oxford University Press 2017. This work is written by (a) US Government employee(s) and is in the public domain in the US.

Initiation and slow propagation of epileptiform activity from ventral to dorsal medial entorhinal cortex is constrained by an inhibitory gradient.

PubMed

Ridler, Thomas; Matthews, Peter; Phillips, Keith G; Randall, Andrew D; Brown, Jonathan T

2018-06-01

The medial entorhinal cortex (mEC) has an important role in initiation and propagation of seizure activity. Several anatomical relationships exist in neurophysiological properties of mEC neurons; however, in the context of hyperexcitability, previous studies often considered it as a homogeneous structure. Using multi-site extracellular recording techniques, ictal-like activity was observed along the dorso-ventral axis of the mEC in vitro in response to various ictogenic stimuli. This originated predominantly from ventral areas, spreading to dorsal mEC with a surprisingly slow velocity. Modulation of inhibitory tone was capable of changing the slope of ictal initiation, suggesting seizure propagation behaviours are highly dependent on levels of GABAergic function in this region. A distinct disinhibition model also showed, in the absence of inhibition, a prevalence for interictal-like initiation in ventral mEC, reflecting the intrinsic differences in mEC neurons. These findings suggest the ventral mEC is more prone to hyperexcitable discharge than the dorsal mEC, which may be relevant under pathological conditions. The medial entorhinal cortex (mEC) has an important role in the generation and propagation of seizure activity. The organization of the mEC is such that a number of dorso-ventral relationships exist in neurophysiological properties of neurons. These range from intrinsic and synaptic properties to density of inhibitory connectivity. We examined the influence of these gradients on generation and propagation of epileptiform activity in the mEC. Using a 16-shank silicon probe array to record along the dorso-ventral axis of the mEC in vitro, we found 4-aminopyridine application produces ictal-like activity originating predominantly in ventral areas. This activity spreads to dorsal mEC at a surprisingly slow velocity (138 μm s -1 ), while cross-site interictal-like activity appeared relatively synchronous. We propose that ictal propagation is constrained by

Electrical and Network Neuronal Properties Are Preferentially Disrupted in Dorsal, But Not Ventral, Medial Entorhinal Cortex in a Mouse Model of Tauopathy

PubMed Central

Booth, Clair A.; Ridler, Thomas; Murray, Tracey K.; Ward, Mark A.; de Groot, Emily; Goodfellow, Marc; Phillips, Keith G.; Randall, Andrew D.

2016-01-01

The entorhinal cortex (EC) is one of the first areas to be disrupted in neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. The responsiveness of individual neurons to electrical and environmental stimuli varies along the dorsal–ventral axis of the medial EC (mEC) in a manner that suggests this topographical organization plays a key role in neural encoding of geometric space. We examined the cellular properties of layer II mEC stellate neurons (mEC-SCs) in rTg4510 mice, a rodent model of neurodegeneration. Dorsoventral gradients in certain intrinsic membrane properties, such as membrane capacitance and afterhyperpolarizations, were flattened in rTg4510 mEC-SCs, while other cellular gradients [e.g., input resistance (Ri), action potential properties] remained intact. Specifically, the intrinsic properties of rTg4510 mEC-SCs in dorsal aspects of the mEC were preferentially affected, such that action potential firing patterns in dorsal mEC-SCs were altered, while those in ventral mEC-SCs were unaffected. We also found that neuronal oscillations in the gamma frequency band (30–80 Hz) were preferentially disrupted in the dorsal mEC of rTg4510 slices, while those in ventral regions were comparatively preserved. These alterations corresponded to a flattened dorsoventral gradient in theta-gamma cross-frequency coupling of local field potentials recorded from the mEC of freely moving rTg4510 mice. These differences were not paralleled by changes to the dorsoventral gradient in parvalbumin staining or neurodegeneration. We propose that the selective disruption to dorsal mECs, and the resultant flattening of certain dorsoventral gradients, may contribute to disturbances in spatial information processing observed in this model of dementia. SIGNIFICANCE STATEMENT The medial entorhinal cortex (mEC) plays a key role in spatial memory and is one of the first areas to express the pathological features of dementia. Neurons of the mEC are

Delayed clearance of cerebrospinal fluid tracer from entorhinal cortex in idiopathic normal pressure hydrocephalus: A glymphatic magnetic resonance imaging study.

PubMed

Eide, Per K; Ringstad, Geir

2018-01-01

The glymphatic system plays a key role for clearance of waste solutes from the rodent brain. We recently found evidence of glymphatic circulation in the human brain when using magnetic resonance imaging (MRI) contrast agent as cerebrospinal fluid (CSF) tracer in conjunction with multiple MRI acquisitions (gMRI). The present study explored the hypothesis that reduced glymphatic clearance in entorhinal cortex (ERC) may be instrumental in idiopathic normal pressure hydrocephalus (iNPH) dementia. gMRI acquisitions were obtained over a 24-48 h time span in cognitively affected iNPH patients and non-cognitively affected patients with suspected CSF leaks. The CSF tracer enrichment was determined as changes in normalized MRI T1 signal units. The study included 30 patients with iNPH and 8 individuals with suspected CSF leaks (i.e. reference individuals). Compared to reference individuals, iNPH patients presented with higher medial temporal lobe atrophy score and Evan's index and inferior ERC thickness. We found delayed clearance of the intrathecal CSF tracer gadobutrol from CSF, the ERC and adjacent white matter, suggesting impaired glymphatic circulation. Reduced clearance and accumulation of toxic waste product such as amyloid-β may be a mechanism behind dementia in iNPH. Glymphatic MRI (gMRI) may become a tool for assessment of early dementia.

Temporally structured replay of neural activity in a model of entorhinal cortex, hippocampus and postsubiculum

PubMed Central

Hasselmo, Michael E.

2008-01-01

The spiking activity of hippocampal neurons during REM sleep exhibits temporally structured replay of spiking occurring during previously experienced trajectories (Louie and Wilson, 2001). Here, temporally structured replay of place cell activity during REM sleep is modeled in a large-scale network simulation of grid cells, place cells and head direction cells. During simulated waking behavior, the movement of the simulated rat drives activity of a population of head direction cells that updates the activity of a population of entorhinal grid cells. The population of grid cells drives the activity of place cells coding individual locations. Associations between location and movement direction are encoded by modification of excitatory synaptic connections from place cells to speed modulated head direction cells. During simulated REM sleep, the population of place cells coding an experienced location activates the head direction cells coding the associated movement direction. Spiking of head direction cells then causes frequency shifts within the population of entorhinal grid cells to update a phase representation of location. Spiking grid cells then activate new place cells that drive new head direction activity. In contrast to models that perform temporally compressed sequence retrieval similar to sharp wave activity, this model can simulate data on temporally structured replay of hippocampal place cell activity during REM sleep at time scales similar to those observed during waking. These mechanisms could be important for episodic memory of trajectories. PMID:18973557

Relationships between hippocampal sharp waves, ripples and fast gamma oscillation: influence of dentate and entorhinal cortical activity

PubMed Central

Sullivan, David; Csicsvari, Jozsef; Mizuseki, Kenji; Montgomery, Sean; Diba, Kamran; Buzsáki, György

2011-01-01

Summary Hippocampal sharp waves (SPW) and associated fast (‘ripple’) oscillations in the CA1 region are among the most synchronous physiological patterns in the mammalian brain. Using two-dimensional arrays of electrodes for recording local field potentials and unit discharges in freely moving rats, we studied the emergence of ripple oscillations (140–220 Hz) and compared their origin and cellular-synaptic mechanisms with fast gamma oscillations (90–140 Hz). We show that (a) hippocampal SPW-Rs and fast gamma oscillations are quantitatively distinct patterns but involve the same networks and share similar mechanisms, (b) both the frequency and magnitude of fast oscillations is positively correlated with the magnitude of SPWs, (c) during both ripples and fast gamma oscillations the frequency of network oscillation is higher in CA1 than in CA3, (d) SPWs and associated firing of neurons are synchronous in the dorsal hippocampus and dorso-medial entorhinal cortex but ripples are confined to the CA1 pyramidal layer and its downstream targets and (e) the emergence of CA3 population bursts, a prerequisite for SPW-ripples, is biased by activity patterns in the dentate gyrus and entorhinal cortex, with highest probability of ripples associated with an ‘optimum’ level of dentate gamma power. We hypothesize that each hippocampal subnetwork possesses distinct resonant properties, tuned by the magnitude of the excitatory drive. PMID:21653864

Medial perirhinal cortex disambiguates confusable objects

PubMed Central

Tyler, Lorraine K.; Monsch, Andreas U.; Taylor, Kirsten I.

2012-01-01

Our brain disambiguates the objects in our cluttered visual world seemingly effortlessly, enabling us to understand their significance and to act appropriately. The role of anteromedial temporal structures in this process, particularly the perirhinal cortex, is highly controversial. In some accounts, the perirhinal cortex is necessary for differentiating between perceptually and semantically confusable objects. Other models claim that the perirhinal cortex neither disambiguates perceptually confusable objects nor plays a unique role in semantic processing. One major hurdle to resolving this central debate is the fact that brain damage in human patients typically encompasses large portions of the anteromedial temporal lobe, such that the identification of individual substructures and precise neuroanatomical locus of the functional impairments has been difficult. We tested these competing accounts in patients with Alzheimer’s disease with varying degrees of atrophy in anteromedial structures, including the perirhinal cortex. To assess the functional contribution of each anteromedial temporal region separately, we used a detailed region of interest approach. From each participant, we obtained magnetic resonance imaging scans and behavioural data from a picture naming task that contrasted naming performance with living and non-living things as a way of manipulating perceptual and semantic confusability; living things are more similar to one another than non-living things, which have more distinctive features. We manually traced neuroanatomical regions of interest on native-space cortical surface reconstructions to obtain mean thickness estimates for the lateral and medial perirhinal cortex and entorhinal cortex. Mean cortical thickness in each region of interest, and hippocampal volume, were submitted to regression analyses predicting naming performance. Importantly, atrophy of the medial perirhinal cortex, but not lateral perirhinal cortex, entorhinal cortex or

Downstream effects of hippocampal sharp wave ripple oscillations on medial entorhinal cortex layer V neurons in vitro.

PubMed

Roth, Fabian C; Beyer, Katinka M; Both, Martin; Draguhn, Andreas; Egorov, Alexei V

2016-12-01

The entorhinal cortex (EC) is a critical component of the medial temporal lobe (MTL) memory system. Local networks within the MTL express a variety of state-dependent network oscillations that are believed to organize neuronal activity during memory formation. The peculiar pattern of sharp wave-ripple complexes (SPW-R) entrains neurons by a very fast oscillation at ∼200 Hz in the hippocampal areas CA3 and CA1 and then propagates through the "output loop" into the EC. The precise mechanisms of SPW-R propagation and the resulting cellular input patterns in the mEC are, however, largely unknown. We therefore investigated the activity of layer V (LV) principal neurons of the medial EC (mEC) during SPW-R oscillations in horizontal mouse brain slices. Intracellular recordings in the mEC were combined with extracellular monitoring of propagating network activity. SPW-R in CA1 were regularly followed by negative field potential deflections in the mEC. Propagation of SPW-R activity from CA1 to the mEC was mostly monosynaptic and excitatory, such that synaptic input to mEC LV neurons directly reflected unit activity in CA1. Comparison with propagating network activity from CA3 to CA1 revealed a similar role of excitatory long-range connections for both regions. However, SPW-R-induced activity in CA1 involved strong recruitment of rhythmic synaptic inhibition and corresponding fast field oscillations, in contrast to the mEC. These differences between features of propagating SPW-R emphasize the differential processing of network activity by each local network of the hippocampal output loop. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Comparison of properties of medial entorhinal cortex layer II neurons in two anatomical dimensions with and without cholinergic activation.

PubMed

Yoshida, Motoharu; Jochems, Arthur; Hasselmo, Michael E

2013-01-01

Mechanisms underlying grid cell firing in the medial entorhinal cortex (MEC) still remain unknown. Computational modeling studies have suggested that cellular properties such as spike frequency adaptation and persistent firing might underlie the grid cell firing. Recent in vivo studies also suggest that cholinergic activation influences grid cell firing. Here we investigated the anatomical distribution of firing frequency adaptation, the medium spike after hyperpolarization potential (mAHP), subthreshold membrane potential oscillations, sag potential, input resistance and persistent firing, in MEC layer II principal cells using in vitro whole-cell patch clamp recordings in rats. Anatomical distributions of these properties were compared along both the dorso-ventral and medio-lateral axes, both with and without the cholinergic receptor agonist carbachol. We found that spike frequency adaptation is significantly stronger in ventral than in dorsal neurons both with and without carbachol. Spike frequency adaptation was significantly correlated with the duration of the mAHP, which also showed a gradient along the dorso-ventral axis. In carbachol, we found that about 50% of MEC layer II neurons show persistent firing which lasted more than 30 seconds. Persistent firing of MEC layer II neurons might contribute to grid cell firing by providing the excitatory drive. Dorso-ventral differences in spike frequency adaptation we report here are opposite from previous predictions by a computational model. We discuss an alternative mechanism as to how dorso-ventral differences in spike frequency adaptation could contribute to different scales of grid spacing.

Contribution of near-threshold currents to intrinsic oscillatory activity in rat medial entorhinal cortex layer II stellate cells

PubMed Central

Boehlen, Anne; Henneberger, Christian; Erchova, Irina

2013-01-01

The temporal lobe is well known for its oscillatory activity associated with exploration, navigation, and learning. Intrinsic membrane potential oscillations (MPOs) and resonance of stellate cells (SCs) in layer II of the entorhinal cortex are thought to contribute to network oscillations and thereby to the encoding of spatial information. Generation of both MPOs and resonance relies on the expression of specific voltage-dependent ion currents such as the hyperpolarization-activated cation current (IH), the persistent sodium current (INaP), and the noninactivating muscarine-modulated potassium current (IM). However, the differential contributions of these currents remain a matter of debate. We therefore examined how they modify neuronal excitability near threshold and generation of near-threshold MPOs and resonance in vitro. We found that resonance mainly relied on IH and was reduced by IH blockers and modulated by cAMP and an IM enhancer but that neither of the currents exhibited full control over MPOs in these cells. As previously reported, IH controlled a theta-frequency component of MPOs such that blockade of IH resulted in fewer regular oscillations that retained low-frequency components and high peak amplitude. However, pharmacological inhibition and augmentation of IM also affected MPO frequencies and amplitudes. In contrast to other cell types, inhibition of INaP did not result in suppression of MPOs but only in a moderation of their properties. We reproduced the experimentally observed effects in a single-compartment stochastic model of SCs, providing further insight into the interactions between different ionic conductances. PMID:23076110

Brain-derived neurotrophic factor transgenic mice exhibit passive avoidance deficits, increased seizure severity and in vitro hyperexcitability in the hippocampus and entorhinal cortex.

PubMed

Croll, S D; Suri, C; Compton, D L; Simmons, M V; Yancopoulos, G D; Lindsay, R M; Wiegand, S J; Rudge, J S; Scharfman, H E

1999-01-01

Transgenic mice overexpressing brain-derived neurotrophic factor from the beta-actin promoter were tested for behavioral, gross anatomical and physiological abnormalities. Brain-derived neurotrophic factor messenger RNA overexpression was widespread throughout brain. Overexpression declined with age, such that levels of overexpression decreased sharply by nine months. Brain-derived neurotrophic factor transgenic mice had no gross deformities or behavioral abnormalities. However, they showed a significant passive avoidance deficit. This deficit was dependent on continued overexpression, and resolved with age as brain-derived neurotrophic factor transcripts decreased. In addition, the brain-derived neurotrophic factor transgenic mice showed increased seizure severity in response to kainic acid. Hippocampal slices from brain-derived neurotrophic factor transgenic mice showed hyperexcitability in area CA3 and entorhinal cortex, but not in dentate gyrus. Finally, area CA1 long-term potentiation was disrupted, indicating abnormal plasticity. Our data suggest that overexpression of brain-derived neurotrophic factor in the brain can interfere with normal brain function by causing learning impairments and increased excitability. The results also support the hypothesis that excess brain-derived neurotrophic factor could be pro-convulsant in the limbic system.

Linear Look-Ahead in Conjunctive Cells: An Entorhinal Mechanism for Vector-Based Navigation

PubMed Central

Kubie, John L.; Fenton, André A.

2012-01-01

The crisp organization of the “firing bumps” of entorhinal grid cells and conjunctive cells leads to the notion that the entorhinal cortex may compute linear navigation routes. Specifically, we propose a process, termed “linear look-ahead,” by which a stationary animal could compute a series of locations in the direction it is facing. We speculate that this computation could be achieved through learned patterns of connection strengths among entorhinal neurons. This paper has three sections. First, we describe the minimal grid cell properties that will be built into our network. Specifically, the network relies on “rigid modules” of neurons, where all members have identical grid scale and orientation, but differ in spatial phase. Additionally, these neurons must be densely interconnected with synapses that are modifiable early in the animal’s life. Second, we investigate whether plasticity during short bouts of locomotion could induce patterns of connections amongst grid cells or conjunctive cells. Finally, we run a simulation to test whether the learned connection patterns can exhibit linear look-ahead. Our results are straightforward. A simulated 30-min walk produces weak strengthening of synapses between grid cells that do not support linear look-ahead. Similar training in a conjunctive cell module produces a small subset of very strong connections between cells. These strong pairs have three properties: the pre- and post-synaptic cells have similar heading direction. The cell pairs have neighboring grid bumps. Finally, the spatial offset of firing bumps of the cell pair is in the direction of the common heading preference. Such a module can produce strong and accurate linear look-ahead starting in any location and extending in any direction. We speculate that this process may: (1) compute linear paths to goals; (2) update grid cell firing during navigation; and (3) stabilize the rigid modules of grid cells and conjunctive cells. PMID:22557948

Differences in Visual-Spatial Input May Underlie Different Compression Properties of Firing Fields for Grid Cell Modules in Medial Entorhinal Cortex

PubMed Central

Raudies, Florian; Hasselmo, Michael E.

2015-01-01

Firing fields of grid cells in medial entorhinal cortex show compression or expansion after manipulations of the location of environmental barriers. This compression or expansion could be selective for individual grid cell modules with particular properties of spatial scaling. We present a model for differences in the response of modules to barrier location that arise from different mechanisms for the influence of visual features on the computation of location that drives grid cell firing patterns. These differences could arise from differences in the position of visual features within the visual field. When location was computed from the movement of visual features on the ground plane (optic flow) in the ventral visual field, this resulted in grid cell spatial firing that was not sensitive to barrier location in modules modeled with small spacing between grid cell firing fields. In contrast, when location was computed from static visual features on walls of barriers, i.e. in the more dorsal visual field, this resulted in grid cell spatial firing that compressed or expanded based on the barrier locations in modules modeled with large spacing between grid cell firing fields. This indicates that different grid cell modules might have differential properties for computing location based on visual cues, or the spatial radius of sensitivity to visual cues might differ between modules. PMID:26584432

The Bioinformatic Analysis of the Dysregulated Genes and MicroRNAs in Entorhinal Cortex, Hippocampus, and Blood for Alzheimer's Disease

PubMed Central

Pang, Xiaocong; Zhao, Ying; Wang, Jinhua; Zhou, Qimeng; Xu, Lvjie; Kang, De

2017-01-01

Aim The incidence of Alzheimer's disease (AD) has been increasing in recent years, but there exists no cure and the pathological mechanisms are not fully understood. This study aimed to find out the pathogenesis of learning and memory impairment, new biomarkers, potential therapeutic targets, and drugs for AD. Methods We downloaded the microarray data of entorhinal cortex (EC) and hippocampus (HIP) of AD and controls from Gene Expression Omnibus (GEO) database, and then the differentially expressed genes (DEGs) in EC and HIP regions were analyzed for functional and pathway enrichment. Furthermore, we utilized the DEGs to construct coexpression networks to identify hub genes and discover the small molecules which were capable of reversing the gene expression profile of AD. Finally, we also analyzed microarray and RNA-seq dataset of blood samples to find the biomarkers related to gene expression in brain. Results We found some functional hub genes, such as ErbB2, ErbB4, OCT3, MIF, CDK13, and GPI. According to GO and KEGG pathway enrichment, several pathways were significantly dysregulated in EC and HIP. CTSD and VCAM1 were dysregulated significantly in blood, EC, and HIP, which were potential biomarkers for AD. Target genes of four microRNAs had similar GO_terms distribution with DEGs in EC and HIP. In addtion, small molecules were screened out for AD treatment. Conclusion These biological pathways and DEGs or hub genes will be useful to elucidate AD pathogenesis and identify novel biomarkers or drug targets for developing improved diagnostics and therapeutics against AD. PMID:29359159

Target-Selectivity of Parvalbumin-Positive Interneurons in Layer II of Medial Entorhinal Cortex in Normal and Epileptic Animals

PubMed Central

Armstrong, Caren; Wang, Jessica; Lee, Soo Yeun; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2015-01-01

The medial entorhinal cortex layer II (MEClayerII) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII. However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII. However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII. Taken together, these findings advance our

Target-selectivity of parvalbumin-positive interneurons in layer II of medial entorhinal cortex in normal and epileptic animals.

PubMed

Armstrong, Caren; Wang, Jessica; Yeun Lee, Soo; Broderick, John; Bezaire, Marianne J; Lee, Sang-Hun; Soltesz, Ivan

2016-06-01

The medial entorhinal cortex layer II (MEClayerII ) is a brain region critical for spatial navigation and memory, and it also demonstrates a number of changes in patients with, and animal models of, temporal lobe epilepsy (TLE). Prior studies of GABAergic microcircuitry in MEClayerII revealed that cholecystokinin-containing basket cells (CCKBCs) select their targets on the basis of the long-range projection pattern of the postsynaptic principal cell. Specifically, CCKBCs largely avoid reelin-containing principal cells that form the perforant path to the ipsilateral dentate gyrus and preferentially innervate non-perforant path forming calbindin-containing principal cells. We investigated whether parvalbumin containing basket cells (PVBCs), the other major perisomatic targeting GABAergic cell population, demonstrate similar postsynaptic target selectivity as well. In addition, we tested the hypothesis that the functional or anatomic arrangement of circuit selectivity is disrupted in MEClayerII in chronic TLE, using the repeated low-dose kainate model in rats. In control animals, we found that PVBCs innervated both principal cell populations, but also had significant selectivity for calbindin-containing principal cells in MEClayerII . However, the magnitude of this preference was smaller than for CCKBCs. In addition, axonal tracing and paired recordings showed that individual PVBCs were capable of contacting both calbindin and reelin-containing principal cells. In chronically epileptic animals, we found that the intrinsic properties of the two principal cell populations, the GABAergic perisomatic bouton numbers, and selectivity of the CCKBCs and PVBCs remained remarkably constant in MEClayerII . However, miniature IPSC frequency was decreased in epilepsy, and paired recordings revealed the presence of direct excitatory connections between principal cells in the MEClayerII in epilepsy, which is unusual in normal adult MEClayerII . Taken together, these findings advance

Aspiration of human neutrophils: effects of shear thinning and cortical dissipation.

PubMed

Drury, J L; Dembo, M

2001-12-01

It is generally accepted that the human neutrophil can be mechanically represented as a droplet of polymeric fluid enclosed by some sort of thin slippery viscoelastic cortex. Many questions remain however about the detailed rheology and chemistry of the interior fluid and the cortex. To address these quantitative issues, we have used a finite element method to simulate the dynamics of neutrophils during micropipet aspiration using various plausible assumptions. The results were then systematically compared with aspiration experiments conducted at eight different combinations of pipet size and pressure. Models in which the cytoplasm was represented by a simple Newtonian fluid (i.e., models without shear thinning) were grossly incapable of accounting for the effects of pressure on the general time scale of neutrophil aspiration. Likewise, models in which the cortex was purely elastic (i.e., models without surface viscosity) were unable to explain the effects of pipet size on the general aspiration rate. Such models also failed to explain the rapid acceleration of the aspiration rate during the final phase of aspiration nor could they account for the geometry of the neutrophil during various phases of aspiration. Thus, our results indicate that a minimal mechanical model of the neutrophil needs to incorporate both shear thinning and surface viscosity to remain valid over a reasonable range of conditions. At low shear rates, the surface dilatation viscosity of the neutrophil was found to be on the order of 100 poise-cm, whereas the viscosity of the interior cytoplasm was on the order of 1000 poise. Both the surface viscosity and the interior viscosity seem to decrease in a similar fashion when the shear rate exceeds approximately 0.05 s(-1). Unfortunately, even models with both surface viscosity and shear thinning studied are still not sufficient to fully explain all the features of neutrophil aspiration. In particular, the very high rate of aspiration during the

Aspiration of human neutrophils: effects of shear thinning and cortical dissipation.

PubMed Central

Drury, J L; Dembo, M

2001-01-01

It is generally accepted that the human neutrophil can be mechanically represented as a droplet of polymeric fluid enclosed by some sort of thin slippery viscoelastic cortex. Many questions remain however about the detailed rheology and chemistry of the interior fluid and the cortex. To address these quantitative issues, we have used a finite element method to simulate the dynamics of neutrophils during micropipet aspiration using various plausible assumptions. The results were then systematically compared with aspiration experiments conducted at eight different combinations of pipet size and pressure. Models in which the cytoplasm was represented by a simple Newtonian fluid (i.e., models without shear thinning) were grossly incapable of accounting for the effects of pressure on the general time scale of neutrophil aspiration. Likewise, models in which the cortex was purely elastic (i.e., models without surface viscosity) were unable to explain the effects of pipet size on the general aspiration rate. Such models also failed to explain the rapid acceleration of the aspiration rate during the final phase of aspiration nor could they account for the geometry of the neutrophil during various phases of aspiration. Thus, our results indicate that a minimal mechanical model of the neutrophil needs to incorporate both shear thinning and surface viscosity to remain valid over a reasonable range of conditions. At low shear rates, the surface dilatation viscosity of the neutrophil was found to be on the order of 100 poise-cm, whereas the viscosity of the interior cytoplasm was on the order of 1000 poise. Both the surface viscosity and the interior viscosity seem to decrease in a similar fashion when the shear rate exceeds approximately 0.05 s(-1). Unfortunately, even models with both surface viscosity and shear thinning studied are still not sufficient to fully explain all the features of neutrophil aspiration. In particular, the very high rate of aspiration during the

Distinct speed dependence of entorhinal island and ocean cells, including respective grid cells

PubMed Central

Sun, Chen; Kitamura, Takashi; Yamamoto, Jun; Martin, Jared; Pignatelli, Michele; Kitch, Lacey J.; Schnitzer, Mark J.; Tonegawa, Susumu

2015-01-01

Entorhinal–hippocampal circuits in the mammalian brain are crucial for an animal’s spatial and episodic experience, but the neural basis for different spatial computations remain unknown. Medial entorhinal cortex layer II contains pyramidal island and stellate ocean cells. Here, we performed cell type-specific Ca2+ imaging in freely exploring mice using cellular markers and a miniature head-mounted fluorescence microscope. We found that both oceans and islands contain grid cells in similar proportions, but island cell activity, including activity in a proportion of grid cells, is significantly more speed modulated than ocean cell activity. We speculate that this differential property reflects island cells’ and ocean cells’ contribution to different downstream functions: island cells may contribute more to spatial path integration, whereas ocean cells may facilitate contextual representation in downstream circuits. PMID:26170279

Cerebral Cortex Regions Selectively Vulnerable to Radiation Dose-Dependent Atrophy

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

Seibert, Tyler M.; Karunamuni, Roshan; Kaifi, Samar

Purpose and Objectives: Neurologic deficits after brain radiation therapy (RT) typically involve decline in higher-order cognitive functions such as attention and memory rather than sensory defects or paralysis. We sought to determine whether areas of the cortex critical to cognition are selectively vulnerable to radiation dose-dependent atrophy. Methods and Materials: We measured change in cortical thickness in 54 primary brain tumor patients who underwent fractionated, partial brain RT. The study patients underwent high-resolution, volumetric magnetic resonance imaging (T1-weighted; T2 fluid-attenuated inversion recovery, FLAIR) before RT and 1 year afterward. Semiautomated software was used to segment anatomic regions of the cerebral cortex formore » each patient. Cortical thickness was measured for each region before RT and 1 year afterward. Two higher-order cortical regions of interest (ROIs) were tested for association between radiation dose and cortical thinning: entorhinal (memory) and inferior parietal (attention/memory). For comparison, 2 primary cortex ROIs were also tested: pericalcarine (vision) and paracentral lobule (somatosensory/motor). Linear mixed-effects analyses were used to test all other cortical regions for significant radiation dose-dependent thickness change. Statistical significance was set at α = 0.05 using 2-tailed tests. Results: Cortical atrophy was significantly associated with radiation dose in the entorhinal (P=.01) and inferior parietal ROIs (P=.02). By contrast, no significant radiation dose-dependent effect was found in the primary cortex ROIs (pericalcarine and paracentral lobule). In the whole-cortex analysis, 9 regions showed significant radiation dose-dependent atrophy, including areas responsible for memory, attention, and executive function (P≤.002). Conclusions: Areas of cerebral cortex important for higher-order cognition may be most vulnerable to radiation-related atrophy. This is consistent with clinical

Laminar and dorsoventral molecular organization of the medial entorhinal cortex revealed by large-scale anatomical analysis of gene expression.

PubMed

Ramsden, Helen L; Sürmeli, Gülşen; McDonagh, Steven G; Nolan, Matthew F

2015-01-01

Neural circuits in the medial entorhinal cortex (MEC) encode an animal's position and orientation in space. Within the MEC spatial representations, including grid and directional firing fields, have a laminar and dorsoventral organization that corresponds to a similar topography of neuronal connectivity and cellular properties. Yet, in part due to the challenges of integrating anatomical data at the resolution of cortical layers and borders, we know little about the molecular components underlying this organization. To address this we develop a new computational pipeline for high-throughput analysis and comparison of in situ hybridization (ISH) images at laminar resolution. We apply this pipeline to ISH data for over 16,000 genes in the Allen Brain Atlas and validate our analysis with RNA sequencing of MEC tissue from adult mice. We find that differential gene expression delineates the borders of the MEC with neighboring brain structures and reveals its laminar and dorsoventral organization. We propose a new molecular basis for distinguishing the deep layers of the MEC and show that their similarity to corresponding layers of neocortex is greater than that of superficial layers. Our analysis identifies ion channel-, cell adhesion- and synapse-related genes as candidates for functional differentiation of MEC layers and for encoding of spatial information at different scales along the dorsoventral axis of the MEC. We also reveal laminar organization of genes related to disease pathology and suggest that a high metabolic demand predisposes layer II to neurodegenerative pathology. In principle, our computational pipeline can be applied to high-throughput analysis of many forms of neuroanatomical data. Our results support the hypothesis that differences in gene expression contribute to functional specialization of superficial layers of the MEC and dorsoventral organization of the scale of spatial representations.

Laminar and Dorsoventral Molecular Organization of the Medial Entorhinal Cortex Revealed by Large-scale Anatomical Analysis of Gene Expression

PubMed Central

Ramsden, Helen L.; Sürmeli, Gülşen; McDonagh, Steven G.; Nolan, Matthew F.

2015-01-01

Neural circuits in the medial entorhinal cortex (MEC) encode an animal’s position and orientation in space. Within the MEC spatial representations, including grid and directional firing fields, have a laminar and dorsoventral organization that corresponds to a similar topography of neuronal connectivity and cellular properties. Yet, in part due to the challenges of integrating anatomical data at the resolution of cortical layers and borders, we know little about the molecular components underlying this organization. To address this we develop a new computational pipeline for high-throughput analysis and comparison of in situ hybridization (ISH) images at laminar resolution. We apply this pipeline to ISH data for over 16,000 genes in the Allen Brain Atlas and validate our analysis with RNA sequencing of MEC tissue from adult mice. We find that differential gene expression delineates the borders of the MEC with neighboring brain structures and reveals its laminar and dorsoventral organization. We propose a new molecular basis for distinguishing the deep layers of the MEC and show that their similarity to corresponding layers of neocortex is greater than that of superficial layers. Our analysis identifies ion channel-, cell adhesion- and synapse-related genes as candidates for functional differentiation of MEC layers and for encoding of spatial information at different scales along the dorsoventral axis of the MEC. We also reveal laminar organization of genes related to disease pathology and suggest that a high metabolic demand predisposes layer II to neurodegenerative pathology. In principle, our computational pipeline can be applied to high-throughput analysis of many forms of neuroanatomical data. Our results support the hypothesis that differences in gene expression contribute to functional specialization of superficial layers of the MEC and dorsoventral organization of the scale of spatial representations. PMID:25615592

Immunotoxic cholinergic lesions in the basal forebrain reverse the effects of entorhinal cortex lesions on conditioned odor aversion in the rat.

PubMed

Ferry, Barbara; Herbeaux, Karin; Cosquer, Brigitte; Traissard, Natalia; Galani, Rodrigue; Cassel, Jean-Christophe

2007-07-01

Conditioned odor aversion (COA) corresponds to the avoidance of an odorized-tasteless solution (conditioned stimulus, CS) previously paired with toxicosis. COA occurs only when the interstimulus interval (ISI) is kept short, suggesting that the memory trace of the odor is subject to rapid decay. Previous experiments have shown that the entorhinal cortex (EC) is involved in the acquisition of COA, since lesion of the EC rendered COA tolerant to long ISI. Because EC lesions induce a septo-hippocampal cholinergic sprouting, the present experiment investigated whether COA tolerance to long ISI may be linked to this sprouting reaction. In a first experiment, male Long-Evans rats subjected to bilateral excitotoxic EC lesions combined to intracerebroventricular infusions of the selective cholinergic immunotoxin 192 IgG-saporin were exposed to odor-toxicosis pairing using a long ISI (120 min). Results showed that EC-lesioned rats displayed COA with the long ISI but not the control groups. In rats with EC combined to 192 IgG-saporin lesions, histological analysis demonstrated no evidence for cholinergic septo-hippocampal sprouting. In a second experiment, animals with 192-IgG saporin lesion showed a marked COA with a short ISI (5 min). These results suggest that the COA with the long ISI found in rats with EC lesions might involve a functional activity related to the EC lesion-induced hippocampal cholinergic sprouting. As the injection of 192 IgG-saporin alone did not affect COA with a short ISI, our data also point to a possible role of hippocampal cholinergic neurons in the modulation of memory processes underlying COA.

Continuity of neuropil threads with tangle-bearing and tangle-free neurons in Alzheimer disease cortex. A confocal laser scanning microscopy study.

PubMed

Schmidt, M L; Murray, J M; Trojanowski, J Q

1993-04-01

Neuropil threads (NTs) are abnormal processes that are associated with tangle-bearing neurons in gray matter areas of Alzheimer disease (AD) brains. Although NTs contain paired helical filaments (PHFs) and share multiple tau epitopes with neurobrillary tangles (NFTs), the relationship between NTs and tangle-bearing neurons is unclear. For this reason, we assessed the continuity of NTs with tangle-bearing and tangle-free neurons. Since astrocytes express low levels of tau and rarely have been shown to contain PHFs, we also examined the relationship of NTs to cortical astrocytes. This was done using histochemical and immunochemical methods in conjunction with confocal laser scanning microscopy to examine NTs in amygdala and entorhinal cortex of seven AD brains. Only a small fraction of NTs (< 1%) in 3.5 x 10(6) microns 3 of amygdala and entorhinal cortex could be traced to local neurons with NFTs or to neurons that did not contain NFTs, and no NTs were continuous with cortical astrocytes. These results indicate that only a very small percentage of NTs in entorhinal cortex and amygdala occur in the most proximal segments of processes that emanate from tangle-bearing or tangle-free neurons. This implies that the majority of NTs reside in the distal parts of dendrites and/or the terminal arborizations of axons or that NTs are discontinuous abnormalities. Taken together, these data suggest that NTs could disrupt local and long distance neuronal circuitry and thereby contribute to the cognitive impairments seen in AD patients.

Dynamical organization of the cytoskeletal cortex probed by micropipette aspiration

PubMed Central

Brugués, Jan; Maugis, Benoit; Casademunt, Jaume; Nassoy, Pierre; Amblard, François; Sens, Pierre

2010-01-01

Bleb-based cell motility proceeds by the successive inflation and retraction of large spherical membrane protrusions (“blebs”) coupled with substrate adhesion. In addition to their role in motility, cellular blebs constitute a remarkable illustration of the dynamical interactions between the cytoskeletal cortex and the plasma membrane. Here we study the bleb-based motions of Entamoeba histolytica in the constrained geometry of a micropipette. We construct a generic theoretical model that combines the polymerization of an actin cortex underneath the plasma membrane with the myosin-generated contractile stress in the cortex and the stress-induced failure of membrane-cortex adhesion. One major parameter dictating the cell response to micropipette suction is the stationary cortex thickness, controlled by actin polymerization and depolymerization. The other relevant physical parameters can be combined into two characteristic cortex thicknesses for which the myosin stress (i) balances the suction pressure and (ii) provokes membrane-cortex unbinding. We propose a general phase diagram for cell motions inside a micropipette by comparing these three thicknesses. In particular, we theoretically predict and experimentally verify the existence of saltatory and oscillatory motions for a well-defined range of micropipette suction pressures. PMID:20713731

The Embryonic Septum and Ventral Pallium, New Sources of Olfactory Cortex Cells

PubMed Central

de Carlos, Juan A.

2012-01-01

The mammalian olfactory cortex is a complex structure located along the rostro-caudal extension of the ventrolateral prosencephalon, which is divided into several anatomically and functionally distinct areas: the anterior olfactory nucleus, piriform cortex, olfactory tubercle, amygdaloid olfactory nuclei, and the more caudal entorhinal cortex. Multiple forebrain progenitor domains contribute to the cellular diversity of the olfactory cortex, which is invaded simultaneously by cells originating in distinct germinal areas in the dorsal and ventral forebrain. Using a combination of dye labeling techniques, we identified two novel areas that contribute cells to the developing olfactory cortices, the septum and the ventral pallium, from which cells migrate along a radial and then a tangential path. We characterized these cell populations by comparing their expression of calretinin, calbindin, reelin and Tbr1 with that of other olfactory cell populations. PMID:22984546

Neural correlates of social odor recognition and the representation of individual distinctive social odors within entorhinal cortex and ventral subiculum.

PubMed

Petrulis, A; Alvarez, P; Eichenbaum, H

2005-01-01

Recognition of individual conspecifics is important for social behavior and requires the formation of memories for individually distinctive social signals. Individual recognition is often mediated by olfactory cues in mammals, especially nocturnal rodents such as golden hamsters. In hamsters, this form of recognition requires main olfactory system input to the lateral entorhinal cortex (LEnt). Here, we tested whether neurons in LEnt and the nearby ventral subiculum (VS) would show cellular correlates of this natural form of recognition memory. Two hundred ninety single neurons were recorded from both superficial (SE) and deep layers of LEnt (DE) and VS while male hamsters investigated volatile odorants from female vaginal secretions. Many neurons encoded differences between female's odors with many discriminating between odors from different individual females but not between different odor samples from the same female. Other neurons discriminated between odor samples from one female and generalized across collections from other females. LEnt and VS neurons showed enhanced or suppressed cellular activity during investigation of previously presented odors and in response to novel odors. A majority of SE neurons decreased firing to odor repetition and increased activity to novel odors. In contrast, DE neurons often showed suppressed activity in response to novel odors. Thus, neurons in LEnt and VS of male hamsters encode information that is critical for the identification and recognition of individual females by odor cues. This study reveals cellular mechanisms in LEnt and VS that may mediate a natural form of recognition memory in hamsters. These neuronal responses were similar to those observed in rats and monkeys during performance in standard recognition memory tasks. Consequently, the present data extend our understanding of the cellular basis for recognition memory and suggest that individual recognition requires similar neural mechanisms as those employed in

Postnatal functional inactivation of the entorhinal cortex or ventral subiculum has different consequences for latent inhibition-related striatal dopaminergic responses in adult rats.

PubMed

Meyer, F; Peterschmitt, Y; Louilot, A

2009-05-01

Latent inhibition has been found to be disrupted in patients with acute schizophrenia. Striatal dopaminergic dysregulation is commonly acknowledged in schizophrenia. This disease may be consecutive to a functional disconnection between integrative regions, stemming from neurodevelopmental failures. Various anomalies suggesting early abnormal brain development have been described in the entorhinal cortex (ENT) and ventral subiculum (SUB) of patients. This study examines the consequences of a neonatal transitory blockade of the left ENT or left SUB for latent inhibition-related dopamine responses in the anterior part of the dorsal striatum using in-vivo voltammetry in freely moving adult rats. Reversible inactivation of both structures in different animals was achieved by local microinjection of tetrodotoxin (TTX) at postnatal day 8. Results obtained during the retention session of a three-stage latent inhibition protocol showed that the functional neonatal disconnection of the ENT or SUB caused the behavioural latent inhibition expression in pre-exposed (PE)-TTX-conditioned adult rats to disappear. After postnatal inactivation of the SUB, PE-TTX-conditioned rats displayed a reversal of the latent inhibition-related striatal dopamine responses, whereas after neonatal blockade of the ENT, dopamine changes in PE-TTX-conditioned rats monitored in the anterior striatum were between those observed in PE-phosphate-buffered-saline-conditioned and non-PE-TTX-conditioned animals. These data suggest that neonatal functional inactivation of the SUB disrupts latent inhibition-related striatal dopamine responses in adult animals more than that of the ENT. They may help improve understanding of the pathophysiology of schizophrenia.

Perirhinal cortex and temporal lobe epilepsy

PubMed Central

Biagini, Giuseppe; D'Antuono, Margherita; Benini, Ruba; de Guzman, Philip; Longo, Daniela; Avoli, Massimo

2013-01-01

The perirhinal cortex—which is interconnected with several limbic structures and is intimately involved in learning and memory—plays major roles in pathological processes such as the kindling phenomenon of epileptogenesis and the spread of limbic seizures. Both features may be relevant to the pathophysiology of mesial temporal lobe epilepsy that represents the most refractory adult form of epilepsy with up to 30% of patients not achieving adequate seizure control. Compared to other limbic structures such as the hippocampus or the entorhinal cortex, the perirhinal area remains understudied and, in particular, detailed information on its dysfunctional characteristics remains scarce; this lack of information may be due to the fact that the perirhinal cortex is not grossly damaged in mesial temporal lobe epilepsy and in models mimicking this epileptic disorder. However, we have recently identified in pilocarpine-treated epileptic rats the presence of selective losses of interneuron subtypes along with increased synaptic excitability. In this review we: (i) highlight the fundamental electrophysiological properties of perirhinal cortex neurons; (ii) briefly stress the mechanisms underlying epileptiform synchronization in perirhinal cortex networks following epileptogenic pharmacological manipulations; and (iii) focus on the changes in neuronal excitability and cytoarchitecture of the perirhinal cortex occurring in the pilocarpine model of mesial temporal lobe epilepsy. Overall, these data indicate that perirhinal cortex networks are hyperexcitable in an animal model of temporal lobe epilepsy, and that this condition is associated with a selective cellular damage that is characterized by an age-dependent sensitivity of interneurons to precipitating injuries, such as status epilepticus. PMID:24009554

Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory.

PubMed

Jacobs, Joshua; Miller, Jonathan; Lee, Sang Ah; Coffey, Tom; Watrous, Andrew J; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn; Gross, Robert E; Sheth, Sameer A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Kahana, Michael J; Rizzuto, Daniel S

2016-12-07

Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory. Copyright © 2016 Elsevier Inc. All rights reserved.

Modulation of the storage of social recognition memory by neurotransmitter systems in the insular cortex.

PubMed

Cavalcante, Lorena E S; Zinn, Carolina G; Schmidt, Scheila D; Saenger, Bruna F; Ferreira, Flávia F; Furini, Cristiane R G; Myskiw, Jociane C; Izquierdo, Ivan

2017-09-15

The insular cortex (IC) receives projections from prefrontal, entorhinal and cingulate cortex, olfactory bulb and basal nuclei and has reciprocal connections with the amygdala and entorhinal cortex. These connections suggest a possible involvement in memory processes; this has been borne out by data on several behaviors. Social recognition memory (SRM) is essential to form social groups and to establish hierarchies and social and affective ties. Despite its importance, knowledge about the brain structures and the neurotransmitter mechanisms involved in its processing is still scarce. Here we study the participation of NMDA-glutamatergic, D1/D5-dopaminergic, H2-histaminergic, β-adrenergic and 5-HT 1A -serotoninergic receptors of the IC in the consolidation of SRM. Male Wistar rats received intra-IC infusions of substances acting on these receptors immediately after the sample phase of a social discrimination task and 24h later were exposed to a 5-min retention test. The intra-IC infusion of antagonists of D1/D5, β-adrenergic or 5-HT 1A receptors immediately after the sample phase impaired the consolidation of SRM. These effects were blocked by the concomitant intra-IC infusion of agonists of these receptors. Antagonists and agonists of NMDA and H2 receptors had no effect on SRM. The results suggest that the dopaminergic D1/D5, β-adrenergic and serotonergic 5-HT 1A receptors in the IC, but not glutamatergic NMDA and the histaminergic H2 receptors, participate in the consolidation of SRM in the IC. Copyright © 2017 Elsevier B.V. All rights reserved.

Epileptiform activity induced by lowering extracellular [Mg2+] in combined hippocampal-entorhinal cortex slices: modulation by receptors for norepinephrine and N-methyl-D-aspartate.

PubMed

Stanton, P K; Jones, R S; Mody, I; Heinemann, U

1987-01-01

Reduction of extracellular Mg2+ concentration induced spontaneous and evoked epileptiform activity in the entorhinal cortex (EC) and dentate gyrus (DG) of combined hippocampus (HC)-EC slices. Extracellular field potentials, as well as changes in extracellular Ca2+ and K+ concentrations, were measured in EC and DG with ion-selective/reference electrodes during both repetitive and single stimuli. In the EC, lowering extracellular [Mg2+] induces both spontaneous and single stimulus evoked ictal events consisting of extracellular negative potential shifts (up to 5 mV, 30 sec), decreases in [Ca2+]0 and increases in [K+]0. In the DG, spontaneous events were much shorter, but similar changes in [Ca2+]0, [K+]0 and field potentials (FPs) could be evoked by brief high-frequency stimulation. In both areas, the N-methyl-D-aspartate (NMDA) receptor antagonist 2-aminophosphonovalerate (2-APV) completely blocked spontaneous as well as stimulus evoked epileptiform events. The neurotransmitter norepinephrine (NE), which has previously been shown to modulate long-term potentiation in the DG, was found to exhibit differential modulation of epileptiform activity in the EC and DG. In the EC, NE, acting via alpha 1-receptors, completely blocked low Mg2+-induced epileptiform activity. In contrast, in the DG, NE exhibited a beta-receptor mediated prolongation of the low Mg2+-induced ictal events, and enhanced the stimulus-induced ionic and field potential changes. From these results, we conclude that lowering extracellular [Mg2+], acting in large part through the removal of the Mg2+ voltage-dependent blockade of NMDA receptors, leads to induction of epileptiform activity in both the EC and DG.(ABSTRACT TRUNCATED AT 250 WORDS)

Temporal Lobe and Frontal-Subcortical Dissociations in Non-Demented Parkinson's Disease with Verbal Memory Impairment.

PubMed

Tanner, Jared J; Mareci, Thomas H; Okun, Michael S; Bowers, Dawn; Libon, David J; Price, Catherine C

2015-01-01

The current investigation examined verbal memory in idiopathic non-dementia Parkinson's disease and the significance of the left entorhinal cortex and left entorhinal-retrosplenial region connections (via temporal cingulum) on memory impairment in Parkinson's disease. Forty non-demented Parkinson's disease patients and forty non-Parkinson's disease controls completed two verbal memory tests--a wordlist measure (Philadelphia repeatable Verbal Memory Test) and a story measure (Logical Memory). All participants received T1-weighted and diffusion magnetic resonance imaging (3T; Siemens) sequences. Left entorhinal volume and left entorhinal-retrosplenial connectivity (temporal cingulum edge weight) were the primary imaging variables of interest with frontal lobe thickness and subcortical structure volumes as dissociating variables. Individuals with Parkinson's disease showed worse verbal memory, smaller entorhinal volumes, but did not differ in entorhinal-retrosplenial connectivity. For Parkinson's disease entorhinal-retrosplenial edge weight had the strongest associations with verbal memory. A subset of Parkinson's disease patients (23%) had deficits (z-scores < -1.5) across both memory measures. Relative to non-impaired Parkinson's peers, this memory-impaired group had smaller entorhinal volumes. Although entorhinal cortex volume was significantly reduced in Parkinson's disease patients relative to non-Parkinson's peers, only white matter connections associated with the entorhinal cortex were significantly associated with verbal memory performance in our sample. There was also no suggestion of contribution from frontal-subcortical gray or frontal white matter regions. These findings argue for additional investigation into medial temporal lobe gray and white matter connectivity for understanding memory in Parkinson's disease.

Age-Group Differences in Medial Cortex Activity Associated with Thinking About Self-Relevant Agendas

PubMed Central

Mitchell, Karen J.; Raye, Carol L.; Ebner, Natalie C.; Tubridy, Shannon M.; Frankel, Hillary; Johnson, Marcia K.

2009-01-01

This functional magnetic resonance imaging (fMRI) study compared young and older adults’ brain activity as they thought about motivationally self-relevant agendas (hopes and aspirations, duties and obligations) and concrete control items (e.g., shape of USA). Young adults’ activity replicated a double dissociation (Johnson et al., 2006): an area of medial frontal gyrus/anterior cingulate cortex was most active during hopes and aspirations trials and an area of medial posterior cortex, primarily posterior cingulate, was most active during duties and obligations trials. Compared to young adults, older adults showed attenuated responses in medial cortex, especially in medial prefrontal cortex, with both less activity during self-relevant trials and less deactivation during control trials. The fMRI data, together with post-scan reports and the behavioral literature on age-group differences in motivational orientation, suggest that the differences in medial cortex seen in this study reflect young and older adults’ focus on different information during motivationally self-relevant thought. Differences also may be related to an age-associated deficit in controlled cognitive processes that are engaged by complex self-reflection and mediated by prefrontal cortex. PMID:19485660

An efficient coding theory for a dynamic trajectory predicts non-uniform allocation of entorhinal grid cells to modules.

PubMed

Mosheiff, Noga; Agmon, Haggai; Moriel, Avraham; Burak, Yoram

2017-06-01

Grid cells in the entorhinal cortex encode the position of an animal in its environment with spatially periodic tuning curves with different periodicities. Recent experiments established that these cells are functionally organized in discrete modules with uniform grid spacing. Here we develop a theory for efficient coding of position, which takes into account the temporal statistics of the animal's motion. The theory predicts a sharp decrease of module population sizes with grid spacing, in agreement with the trend seen in the experimental data. We identify a simple scheme for readout of the grid cell code by neural circuitry, that can match in accuracy the optimal Bayesian decoder. This readout scheme requires persistence over different timescales, depending on the grid cell module. Thus, we propose that the brain may employ an efficient representation of position which takes advantage of the spatiotemporal statistics of the encoded variable, in similarity to the principles that govern early sensory processing.

An efficient coding theory for a dynamic trajectory predicts non-uniform allocation of entorhinal grid cells to modules

PubMed Central

Mosheiff, Noga; Agmon, Haggai; Moriel, Avraham

2017-01-01

Grid cells in the entorhinal cortex encode the position of an animal in its environment with spatially periodic tuning curves with different periodicities. Recent experiments established that these cells are functionally organized in discrete modules with uniform grid spacing. Here we develop a theory for efficient coding of position, which takes into account the temporal statistics of the animal’s motion. The theory predicts a sharp decrease of module population sizes with grid spacing, in agreement with the trend seen in the experimental data. We identify a simple scheme for readout of the grid cell code by neural circuitry, that can match in accuracy the optimal Bayesian decoder. This readout scheme requires persistence over different timescales, depending on the grid cell module. Thus, we propose that the brain may employ an efficient representation of position which takes advantage of the spatiotemporal statistics of the encoded variable, in similarity to the principles that govern early sensory processing. PMID:28628647

Entorhinal-CA3 Dual-Input Control of Spike Timing in the Hippocampus by Theta-Gamma Coupling.

PubMed

Fernández-Ruiz, Antonio; Oliva, Azahara; Nagy, Gergő A; Maurer, Andrew P; Berényi, Antal; Buzsáki, György

2017-03-08

Theta-gamma phase coupling and spike timing within theta oscillations are prominent features of the hippocampus and are often related to navigation and memory. However, the mechanisms that give rise to these relationships are not well understood. Using high spatial resolution electrophysiology, we investigated the influence of CA3 and entorhinal inputs on the timing of CA1 neurons. The theta-phase preference and excitatory strength of the afferent CA3 and entorhinal inputs effectively timed the principal neuron activity, as well as regulated distinct CA1 interneuron populations in multiple tasks and behavioral states. Feedback potentiation of distal dendritic inhibition by CA1 place cells attenuated the excitatory entorhinal input at place field entry, coupled with feedback depression of proximal dendritic and perisomatic inhibition, allowing the CA3 input to gain control toward the exit. Thus, upstream inputs interact with local mechanisms to determine theta-phase timing of hippocampal neurons to support memory and spatial navigation. Copyright © 2017 Elsevier Inc. All rights reserved.

Associative-memory representations emerge as shared spatial patterns of theta activity spanning the primate temporal cortex

PubMed Central

Nakahara, Kiyoshi; Adachi, Ken; Kawasaki, Keisuke; Matsuo, Takeshi; Sawahata, Hirohito; Majima, Kei; Takeda, Masaki; Sugiyama, Sayaka; Nakata, Ryota; Iijima, Atsuhiko; Tanigawa, Hisashi; Suzuki, Takafumi; Kamitani, Yukiyasu; Hasegawa, Isao

2016-01-01

Highly localized neuronal spikes in primate temporal cortex can encode associative memory; however, whether memory formation involves area-wide reorganization of ensemble activity, which often accompanies rhythmicity, or just local microcircuit-level plasticity, remains elusive. Using high-density electrocorticography, we capture local-field potentials spanning the monkey temporal lobes, and show that the visual pair-association (PA) memory is encoded in spatial patterns of theta activity in areas TE, 36, and, partially, in the parahippocampal cortex, but not in the entorhinal cortex. The theta patterns elicited by learned paired associates are distinct between pairs, but similar within pairs. This pattern similarity, emerging through novel PA learning, allows a machine-learning decoder trained on theta patterns elicited by a particular visual item to correctly predict the identity of those elicited by its paired associate. Our results suggest that the formation and sharing of widespread cortical theta patterns via learning-induced reorganization are involved in the mechanisms of associative memory representation. PMID:27282247

Auto-cortex of crystalline lens-induced iris neovascularization

PubMed Central

Liu, Lin; Li, Yong-Ping; Zhang, Bo; Zhang, Wen-Xin

2012-01-01

AIM To investigate auto-cortex of crystalline lens induced iris neovascularization (INV). METHODS Thirty-six eyes of 36 guinea-pigs were included and divided into three groups randomly in this cohort study. Group A: the right lens nucleus was extracted and the remaining cortical lens material was aspirated thoroughly. Group B: the lens was removed and 30µL precipitated lens cortex was injected into the anterior chamber again. Group C: aspirated the lens cortex of the left eyes and inject them into the right anterior chambers about 10µL. Clinical changes were followed by slit-lamp examination and photograph. The eye balls were enucleated at the day of 2, 4, 7, 11, 13, 17 after operation. HE was used to detect the pathological changes. RESULTS Group A: INV had not been observed until the end of empirical study. The stromal layer contained thick wall vessels, without expansion. Group B: All eyes developed INV. Postoperative (po) 7 days; the eyes developed intense and extensive INV. The vessels of iris expanded remarkably and neovascularization was observed erupting from it's lateral wall and stretching towards the anterior surface. Po11 days, INV regressed gradually after lens cortex had been absorbed. Group C: Po four (4) days, new blood vessels liking red line were presented on the anterior surface of the iris and they were not obvious. CONCLUSION Anterior chamber inside lens coriaceous can induce iris new blood vessels. PMID:22553749

Lateralized Spatial and Object Memory Encoding in Entorhinal and Perirhinal Cortices

ERIC Educational Resources Information Center

Bellgowan, Patrick S. F.; Buffalo, Elizabeth A.; Bodurka, Jerzy; Martin, Alex

2009-01-01

The perirhinal and entorhinal cortices are critical components of the medial temporal lobe (MTL) declarative memory system. Study of their specific functions using blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI), however, has suffered from severe magnetic susceptibility signal dropout resulting in poor…

G9a/GLP histone lysine dimethyltransferase complex activity in the hippocampus and the entorhinal cortex is required for gene activation and silencing during memory consolidation.

PubMed

Gupta-Agarwal, Swati; Franklin, Aimee V; Deramus, Thomas; Wheelock, Muriah; Davis, Robin L; McMahon, Lori L; Lubin, Farah D

2012-04-18

Learning triggers alterations in gene transcription in brain regions such as the hippocampus and the entorhinal cortex (EC) that are necessary for long-term memory (LTM) formation. Here, we identify an essential role for the G9a/G9a-like protein (GLP) lysine dimethyltransferase complex and the histone H3 lysine 9 dimethylation (H3K9me2) marks it catalyzes, in the transcriptional regulation of genes in area CA1 of the rat hippocampus and the EC during memory consolidation. Contextual fear learning increased global levels of H3K9me2 in area CA1 and the EC, with observable changes at the Zif268, DNMT3a, BDNF exon IV, and cFOS gene promoters, which occurred in concert with mRNA expression. Inhibition of G9a/GLP in the EC, but not in the hippocampus, enhanced contextual fear conditioning relative to control animals. The inhibition of G9a/GLP in the EC induced several histone modifications that include not only methylation but also acetylation. Surprisingly, we found that downregulation of G9a/GLP activity in the EC enhanced H3K9me2 in area CA1, resulting in transcriptional silencing of the non-memory permissive gene COMT in the hippocampus. In addition, synaptic plasticity studies at two distinct EC-CA1 cellular pathways revealed that G9a/GLP activity is critical for hippocampus-dependent long-term potentiation initiated in the EC via the perforant pathway, but not the temporoammonic pathway. Together, these data demonstrate that G9a/GLP differentially regulates gene transcription in the hippocampus and the EC during memory consolidation. Furthermore, these findings support the possibility of a role for G9a/GLP in the regulation of cellular and molecular cross talk between these two brain regions during LTM formation.

Histamine facilitates GABAergic transmission in the rat entorhinal cortex: Roles of H1 and H2 receptors, Na+ -permeable cation channels, and inward rectifier K+ channels.

PubMed

Cilz, Nicholas I; Lei, Saobo

2017-05-01

In the brain, histamine (HA) serves as a neuromodulator and a neurotransmitter released from the tuberomammillary nucleus (TMN). HA is involved in wakefulness, thermoregulation, energy homeostasis, nociception, and learning and memory. The medial entorhinal cortex (MEC) receives inputs from the TMN and expresses HA receptors (H 1 , H 2 , and H 3 ). We investigated the effects of HA on GABAergic transmission in the MEC and found that HA significantly increased the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) with an EC 50 of 1.3 µM, but failed to significantly alter sIPSC amplitude. HA-induced increases in sIPSC frequency were sensitive to tetrodotoxin (TTX), required extracellular Ca 2+ , and persisted when GDP-β-S, a G-protein inactivator, was applied postsynaptically via the recording pipettes, indicating that HA increased GABA release by facilitating the excitability of GABAergic interneurons in the MEC. Recordings from local MEC interneurons revealed that HA significantly increased their excitability as determined by membrane depolarization, generation of an inward current at -65 mV, and augmentation of action potential firing frequency. Both H 1 and H 2 receptors were involved in HA-induced increases in sIPSCs and interneuron excitability. Immunohistochemical staining showed that both H 1 and H 2 receptors are expressed on GABAergic interneurons in the MEC. HA-induced depolarization of interneurons involved a mixed ionic mechanism including activation of a Na + -permeable cation channel and inhibition of a cesium-sensitive inward rectifier K + channel, although HA also inhibited the delayed rectifier K + channels. Our results may provide a cellular mechanism, at least partially, to explain the roles of HA in the brain. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The human brain representation of odor identification.

PubMed

Kjelvik, Grete; Evensmoen, Hallvard R; Brezova, Veronika; Håberg, Asta K

2012-07-01

Odor identification (OI) tests are increasingly used clinically as biomarkers for Alzheimer's disease and schizophrenia. The aim of this study was to directly compare the neuronal correlates to identified odors vs. nonidentified odors. Seventeen females with normal olfactory function underwent a functional magnetic resonance imaging (fMRI) experiment with postscanning assessment of spontaneous uncued OI. An event-related analysis was performed to compare within-subject activity to spontaneously identified vs. nonidentified odors at the whole brain level, and in anatomic and functional regions of interest (ROIs) in the medial temporal lobe (MTL). Parameter estimate values and blood oxygenated level-dependent (BOLD) signal curves for correctly identified and nonidentified odors were derived from functional ROIs in hippocampus, entorhinal, piriform, and orbitofrontal cortices. Number of activated voxels and max parameter estimate values were obtained from anatomic ROIs in the hippocampus and the entorhinal cortex. At the whole brain level the correct OI gave rise to increased activity in the left entorhinal cortex and secondary olfactory structures, including the orbitofrontal cortex. Increased activation was also observed in fusiform, primary visual, and auditory cortices, inferior frontal plus inferior temporal gyri. The anatomic MTL ROI analysis showed increased activation in the left entorhinal cortex, right hippocampus, and posterior parahippocampal gyri in correct OI. In the entorhinal cortex and hippocampus the BOLD signal increased specifically in response to identified odors and decreased for nonidentified odors. In orbitofrontal and piriform cortices both identified and nonidentified odors gave rise to an increased BOLD signal, but the response to identified odors was significantly greater than that for nonidentified odors. These results support a specific role for entorhinal cortex and hippocampus in OI, whereas piriform and orbitofrontal cortices are

Parvalbumin interneurons and calretinin fibers arising from the thalamic nucleus reuniens degenerate in the subiculum after kainic acid-induced seizures

PubMed Central

Drexel, M.; Preidt, A.P.; Kirchmair, E.; Sperk, G.

2011-01-01

The subiculum is the major output area of the hippocampus. It is closely interconnected with the entorhinal cortex and other parahippocampal areas. In animal models of temporal lobe epilepsy (TLE) and in TLE patients it exerts increased network excitability and may crucially contribute to the propagation of limbic seizures. Using immunohistochemistry and in situ-hybridization we now investigated neuropathological changes affecting parvalbumin and calretinin containing neurons in the subiculum and other parahippocampal areas after kainic acid-induced status epilepticus. We observed prominent losses in parvalbumin containing interneurons in the subiculum and entorhinal cortex, and in the principal cell layers of the pre- and parasubiculum. Degeneration of parvalbumin-positive neurons was associated with significant precipitation of parvalbumin-immunoreactive debris 24 h after kainic acid injection. In the subiculum the superficial portion of the pyramidal cell layer was more severely affected than its deep part. In the entorhinal cortex, the deep layers were more severely affected than the superficial ones. The decrease in number of parvalbumin-positive neurons in the subiculum and entorhinal cortex correlated with the number of spontaneous seizures subsequently experienced by the rats. The loss of parvalbumin neurons thus may contribute to the development of spontaneous seizures. On the other hand, surviving parvalbumin neurons revealed markedly increased expression of parvalbumin mRNA notably in the pyramidal cell layer of the subiculum and in all layers of the entorhinal cortex. This indicates increased activity of these neurons aiming to compensate for the partial loss of this functionally important neuron population. Furthermore, calretinin-positive fibers terminating in the molecular layer of the subiculum, in sector CA1 of the hippocampus proper and in the entorhinal cortex degenerated together with their presumed perikarya in the thalamic nucleus reuniens. In

Disruption of amygdala-entorhinal-hippocampal network in late-life depression.

PubMed

Leal, Stephanie L; Noche, Jessica A; Murray, Elizabeth A; Yassa, Michael A

2017-04-01

Episodic memory deficits are evident in late-life depression (LLD) and are associated with subtle synaptic and neurochemical changes in the medial temporal lobes (MTL). However, the particular mechanisms by which memory impairment occurs in LLD are currently unknown. We tested older adults with (DS+) and without (DS-) depressive symptoms using high-resolution fMRI that is capable of discerning signals in hippocampal subfields and amygdala nuclei. Scanning was conducted during performance of an emotional discrimination task used previously to examine the relationship between depressive symptoms and amygdala-mediated emotional modulation of hippocampal pattern separation in young adults. We found that hippocampal dentate gyrus (DG)/CA3 activity was reduced during correct discrimination of negative stimuli and increased during correct discrimination of neutral items in DS+ compared to DS- adults. The extent of the latter increase was correlated with symptom severity. Furthermore, DG/CA3 and basolateral amygdala (BLA) activity predicted discrimination performance on negative trials, a relationship that depended on symptom severity. The impact of the BLA on depressive symptom severity was mediated by the DG/CA3 during discrimination of neutral items, and by the lateral entorhinal cortex (LEC) during false recognition of positive items. These results shed light on a novel mechanistic account for amygdala-hippocampal network changes and concurrent alterations in emotional episodic memory in LLD. The BLA-LEC-DG/CA3 network, which comprises a key pathway by which emotion modulates memory, is specifically implicated in LLD. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Bone marrow aspiration

MedlinePlus

Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

Functional Division of Hippocampal Area CA1 Via Modulatory Gating of Entorhinal Cortical Inputs

PubMed Central

Ito, Hiroshi T.; Schuman, Erin M.

2013-01-01

The hippocampus receives two streams of information, spatial and nonspatial, via major afferent inputs from the medial (MEC) and lateral entorhinal cortexes (LEC). The MEC and LEC projections in the temporoammonic pathway are topographically organized along the transverse-axis of area CA1. The potential for functional segregation of area CA1, however, remains relatively unexplored. Here, we demonstrated differential novelty-induced c-Fos expression along the transverse-axis of area CA1 corresponding to topographic projections of MEC and LEC inputs. We found that, while novel place exposure induced a uniform c-Fos expression along the transverse-axis of area CA1, novel object exposure primarily activated the distal half of CA1 neurons. In hippocampal slices, we observed distinct presynaptic properties between LEC and MEC terminals, and application of either DA or NE produced a largely selective influence on one set of inputs (LEC). Finally, we demonstrated that differential c-Fos expression along the transverse axis of area CA1 was largely abolished by an antagonist of neuromodulatory receptors, clozapine. Our results suggest that neuromodulators can control topographic TA projections allowing the hippocampus to differentially encode new information along the transverse axis of area CA1. PMID:21240920

Medial cortex activity, self-reflection and depression.

PubMed

Johnson, Marcia K; Nolen-Hoeksema, Susan; Mitchell, Karen J; Levin, Yael

2009-12-01

Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so.

Medial cortex activity, self-reflection and depression

PubMed Central

Nolen-Hoeksema, Susan; Mitchell, Karen J.; Levin, Yael

2009-01-01

Using functional magnetic resonance imaging, we investigated neural activity associated with self-reflection in depressed [current major depressive episode (MDE)] and healthy control participants, focusing on medial cortex areas previously shown to be associated with self-reflection. Both the MDE and healthy control groups showed greater activity in anterior medial cortex (medial frontal gyrus, anterior cingulate gyrus) when cued to think about hopes and aspirations compared with duties and obligations, and greater activity in posterior medial cortex (precuneus, posterior cingulate) when cued to think about duties and obligations (Experiment 1). However, the MDE group showed less activity than controls in the same area of medial frontal cortex when self-referential cues were more ambiguous with respect to valence (Experiment 2), and less deactivation in a non-self-referential condition in both experiments. Furthermore, individual differences in rumination were positively correlated with activity in both anterior and posterior medial cortex during non-self-referential conditions. These results provide converging evidence for a dissociation of anterior and posterior medial cortex depending on the focus of self-relevant thought. They also provide neural evidence consistent with behavioral findings that depression is associated with disruption of positively valenced thoughts in response to ambiguous cues, and difficulty disengaging from self-reflection when it is appropriate to do so. PMID:19620180

Animal model of dementia induced by entorhinal synaptic damage and partial restoration of cognitive deficits by BDNF and carnitine.

PubMed

Ando, Susumu; Kobayashi, Satoru; Waki, Hatsue; Kon, Kazuo; Fukui, Fumiko; Tadenuma, Tomoko; Iwamoto, Machiko; Takeda, Yasuo; Izumiyama, Naotaka; Watanabe, Kazutada; Nakamura, Hiroaki

2002-11-01

A rat dementia model with cognitive deficits was generated by synapse-specific lesions using botulinum neurotoxin (BoNTx) type B in the entorhinal cortex. To detect cognitive deficits, different tasks were needed depending upon the age of the model animals. Impaired learning and memory with lesions were observed in adult rats using the Hebb-Williams maze, AKON-1 maze and a continuous alternation task in T-maze. Cognitive deficits in lesioned aged rats were detected by a continuous alternation and delayed non-matching-to-sample tasks in T-maze. Adenovirus-mediated BDNF gene expression enhanced neuronal plasticity, as revealed by behavioral tests and LTP formation. Chronic administration of carnitine over time pre- and post-lesions seemed to partially ameliorate the cognitive deficits caused by the synaptic lesion. The carnitine-accelerated recovery from synaptic damage was observed by electron microscopy. These results demonstrate that the BoNTx-lesioned rat can be used as a model for dementia and that cognitive deficits can be alleviated in part by BDNF gene transfer or carnitine administration. Copyright 2002 Wiley-Liss, Inc.

Functional organization of the medial temporal lobe memory system following neonatal hippocampal lesion in rhesus monkeys.

PubMed

Chareyron, Loïc J; Banta Lavenex, Pamela; Amaral, David G; Lavenex, Pierre

2017-12-01

Hippocampal damage in adult humans impairs episodic and semantic memory, whereas hippocampal damage early in life impairs episodic memory but leaves semantic learning relatively preserved. We have previously shown a similar behavioral dissociation in nonhuman primates. Hippocampal lesion in adult monkeys prevents allocentric spatial relational learning, whereas spatial learning persists following neonatal lesion. Here, we quantified the number of cells expressing the immediate-early gene c-fos, a marker of neuronal activity, to characterize the functional organization of the medial temporal lobe memory system following neonatal hippocampal lesion. Ninety minutes before brain collection, three control and four adult monkeys with bilateral neonatal hippocampal lesions explored a novel environment to activate brain structures involved in spatial learning. Three other adult monkeys with neonatal hippocampal lesions remained in their housing quarters. In unlesioned monkeys, we found high levels of c-fos expression in the intermediate and caudal regions of the entorhinal cortex, and in the perirhinal, parahippocampal, and retrosplenial cortices. In lesioned monkeys, spatial exploration induced an increase in c-fos expression in the intermediate field of the entorhinal cortex, the perirhinal, parahippocampal, and retrosplenial cortices, but not in the caudal entorhinal cortex. These findings suggest that different regions of the medial temporal lobe memory system may require different types of interaction with the hippocampus in support of memory. The caudal perirhinal cortex, the parahippocampal cortex, and the retrosplenial cortex may contribute to spatial learning in the absence of functional hippocampal circuits, whereas the caudal entorhinal cortex may require hippocampal output to support spatial learning.

Detecting and discriminating novel objects: The impact of perirhinal cortex disconnection on hippocampal activity patterns

PubMed Central

Amin, Eman; Olarte‐Sánchez, Cristian M.; Aggleton, John P.

2016-01-01

ABSTRACT Perirhinal cortex provides object‐based information and novelty/familiarity information for the hippocampus. The necessity of these inputs was tested by comparing hippocampal c‐fos expression in rats with or without perirhinal lesions. These rats either discriminated novel from familiar objects (Novel‐Familiar) or explored pairs of novel objects (Novel‐Novel). Despite impairing Novel‐Familiar discriminations, the perirhinal lesions did not affect novelty detection, as measured by overall object exploration levels (Novel‐Novel condition). The perirhinal lesions also largely spared a characteristic network of linked c‐fos expression associated with novel stimuli (entorhinal cortex→CA3→distal CA1→proximal subiculum). The findings show: I) that perirhinal lesions preserve behavioral sensitivity to novelty, whilst still impairing the spontaneous ability to discriminate novel from familiar objects, II) that the distinctive patterns of hippocampal c‐fos activity promoted by novel stimuli do not require perirhinal inputs, III) that entorhinal Fos counts (layers II and III) increase for novelty discriminations, IV) that hippocampal c‐fos networks reflect proximal‐distal connectivity differences, and V) that discriminating novelty creates different pathway interactions from merely detecting novelty, pointing to top‐down effects that help guide object selection. © 2016 The Authors Hippocampus Published by Wiley Periodicals, Inc. PMID:27398938

A Goal Direction Signal in the Human Entorhinal/Subicular Region

PubMed Central

Chadwick, Martin J.; Jolly, Amy E.J.; Amos, Doran P.; Hassabis, Demis; Spiers, Hugo J.

2015-01-01

Summary Navigating to a safe place, such as a home or nest, is a fundamental behavior for all complex animals. Determining the direction to such goals is a crucial first step in navigation. Surprisingly, little is known about how or where in the brain this “goal direction signal” is represented. In mammals, “head-direction cells” are thought to support this process, but despite 30 years of research, no evidence for a goal direction representation has been reported [1, 2]. Here, we used fMRI to record neural activity while participants made goal direction judgments based on a previously learned virtual environment. We applied multivoxel pattern analysis [3–5] to these data and found that the human entorhinal/subicular region contains a neural representation of intended goal direction. Furthermore, the neural pattern expressed for a given goal direction matched the pattern expressed when simply facing that same direction. This suggests the existence of a shared neural representation of both goal and facing direction. We argue that this reflects a mechanism based on head-direction populations that simulate future goal directions during route planning [6]. Our data further revealed that the strength of direction information predicts performance. Finally, we found a dissociation between this geocentric information in the entorhinal/subicular region and egocentric direction information in the precuneus. PMID:25532898

Major depressive episodes over the course of 7 years and hippocampal subfield volumes at 7 tesla MRI: the PREDICT-MR study.

PubMed

Wisse, L E M; Biessels, G J; Stegenga, B T; Kooistra, M; van der Veen, P H; Zwanenburg, J J M; van der Graaf, Y; Geerlings, M I

2015-04-01

Smaller hippocampal volumes have been associated with major depressive disorder (MDD). The hippocampus consists of several subfields that may be differentially related to MDD. We investigated the association of occurrence of major depressive episodes (MDEs), assessed five times over seven years, with hippocampal subfield and entorhinal cortex volumes at 7 tesla MRI. In this prospective study of randomly selected general practice attendees, MDEs according to DSM-IV-R criteria were assessed at baseline and after 6, 12, 39 and 84 months follow-up. At the last follow-up, a T2 (0.7 mm(3)) 7 tesla MRI scan was obtained in 47 participants (60±10 years). The subiculum, cornu ammonis (CA) 1 to 3, dentate gyrus&CA4 and entorhinal cortex volumes were manually segmented according a published protocol. Of the 47 participants, 13 had one MDE and 5 had multiple MDEs. ANCOVAs, adjusted for age, sex, education and intracranial volume, revealed no significant differences in hippocampal subfield or entorhinal cortex volumes between participants with and without an MDE in the preceding 84 months. Multiple episodes were associated with smaller subiculum volumes (B=-0.03 mL/episode; 95% CI -0.06; -0.003), but not with the other hippocampal subfield volumes, entorhinal cortex, or total hippocampal volume. A limitation of this study is the small sample size which makes replication necessary. In this exploratory study, we found that an increasing number of major depressive episodes was associated with smaller subiculum volumes in middle-aged and older persons, but not with smaller volumes in other hippocampal subfields or the entorhinal cortex. Copyright © 2014 Elsevier B.V. All rights reserved.

Tau Pathology Induces Excitatory Neuron Loss, Grid Cell Dysfunction and Spatial Memory Deficits Reminiscent of Early Alzheimer's Disease

PubMed Central

Fu, Hongjun; Rodriguez, Gustavo A.; Herman, Mathieu; Emrani, Sheina; Nahmani, Eden; Barrett, Geoffrey; Figueroa, Helen Y.; Goldberg, Eliana

2017-01-01

Summary The earliest stages of Alzheimer's disease (AD) are characterized by the formation of mature tangles in the entorhinal cortex and disorientation and confusion navigating familiar places. The medial entorhinal cortex (MEC) contains specialized neurons called grid cells that form part of the spatial navigation system. Here we show in a transgenic mouse model expressing mutant human tau predominantly in the EC that the formation of mature tangles in old mice was associated with excitatory cell loss and deficits in grid cell function, including destabilized grid fields and reduced firing rates, as well as altered network activity. Overt tau pathology in the aged mice was accompanied by spatial memory deficits. Therefore, tau pathology initiated in the entorhinal cortex could lead to deficits in grid cell firing and underlie the deterioration of spatial cognition seen in human AD. PMID:28111080

Accounting for the Confound of Meninges in Segmenting Entorhinal and Perirhinal Cortices in T1-Weighted MRI.

PubMed

Xie, Long; Wisse, Laura E M; Das, Sandhitsu R; Wang, Hongzhi; Wolk, David A; Manjón, Jose V; Yushkevich, Paul A

2016-10-01

Quantification of medial temporal lobe (MTL) cortices, including entorhinal cortex (ERC) and perirhinal cortex (PRC), from in vivo MRI is desirable for studying the human memory system as well as in early diagnosis and monitoring of Alzheimer's disease. However, ERC and PRC are commonly over-segmented in T1-weighted (T1w) MRI because of the adjacent meninges that have similar intensity to gray matter in T1 contrast. This introduces errors in the quantification and could potentially confound imaging studies of ERC/PRC. In this paper, we propose to segment MTL cortices along with the adjacent meninges in T1w MRI using an established multi-atlas segmentation framework together with super-resolution technique. Experimental results comparing the proposed pipeline with existing pipelines support the notion that a large portion of meninges is segmented as gray matter by existing algorithms but not by our algorithm. Cross-validation experiments demonstrate promising segmentation accuracy. Further, agreement between the volume and thickness measures from the proposed pipeline and those from the manual segmentations increase dramatically as a result of accounting for the confound of meninges. Evaluated in the context of group discrimination between patients with amnestic mild cognitive impairment and normal controls, the proposed pipeline generates more biologically plausible results and improves the statistical power in discriminating groups in absolute terms comparing to other techniques using T1w MRI. Although the performance of the proposed pipeline is inferior to that using T2-weighted MRI, which is optimized to image MTL sub-structures, the proposed pipeline could still provide important utilities in analyzing many existing large datasets that only have T1w MRI available.

Distinct Spatiotemporal Activation Patterns of the Perirhinal-Entorhinal Network in Response to Cortical and Amygdala Input

PubMed Central

Willems, Janske G. P.; Wadman, Wytse J.; Cappaert, Natalie L. M.

2016-01-01

The perirhinal (PER) and entorhinal cortex (EC) receive input from the agranular insular cortex (AiP) and the subcortical lateral amygdala (LA) and the main output area is the hippocampus. Information transfer through the PER/EC network however, is not always guaranteed. It is hypothesized that this network actively regulates the (sub)cortical activity transfer to the hippocampal network and that the inhibitory system is involved in this function. This study determined the recruitment by the AiP and LA afferents in PER/EC network with the use of voltage sensitive dye (VSD) imaging in horizontal mouse brain slices. Electrical stimulation (500 μA) of the AiP induced activity that gradually propagated predominantly in the rostro-caudal direction: from the PER to the lateral EC (LEC). In the presence of 1 μM of the competitive γ-aminobutyric acid (GABAA) receptor antagonist bicuculline, AiP stimulation recruited the medial EC (MEC) as well. In contrast, LA stimulation (500 μA) only induced activity in the deep layers of the PER. In the presence of bicuculline, the initial population activity in the PER propagated further towards the superficial layers and the EC after a delay. The latency of evoked responses decreased with increasing stimulus intensities (50–500 μA) for both the AiP and LA stimuli. The stimulation threshold for evoking responses in the PER/EC network was higher for the LA than for the AiP. This study showed that the extent of the PER/EC network activation depends on release of inhibition. When GABAA dependent inhibition is reduced, both the AiP and the LA activate spatially overlapping regions, although in a distinct spatiotemporal fashion. It is therefore hypothesized that the inhibitory network regulates excitatory activity from both cortical and subcortical areas that has to be transmitted through the PER/EC network. PMID:27378860

Second-wave hydrodissection for aspiration of cortical remains after femtosecond laser-assisted cataract surgery.

PubMed

Lake, Jonathan C; Boianovsky, Celso; de Faria Pacini, Thiago; Crema, Armando

2018-06-14

We describe the technique of second-wave hydrodissection (the first wave being the initial cortical cleaving hydrodissection) performed after the removal of the cataract nucleus in femtosecond laser-assisted cataract surgery. After femtosecond laser application, the cortex is typically found adhered to the anterior capsule. Under high magnification, a steady stream of a balanced salt solution is directed toward the anterior capsule using a hydrodissection cannula. Full cleavage of the remaining cortex is observed by noting the appearance of a dark inner circle by the capsulotomy edge once the balanced salt solution wave has separated the cortex from the capsule. Irrigation/aspiration (I/A) of the cortical remains after the second wave is faster than I/A without this step in femtosecond laser-assisted cataract surgery. Copyright © 2018 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Post-Inhibitory Rebound Spikes in Rat Medial Entorhinal Layer II/III Principal Cells: In Vivo, In Vitro, and Computational Modeling Characterization

PubMed Central

Ferrante, Michele; Shay, Christopher F.; Tsuno, Yusuke; William Chapman, G.; Hasselmo, Michael E.

2017-01-01

Abstract Medial entorhinal cortex Layer-II stellate cells (mEC-LII-SCs) primarily interact via inhibitory interneurons. This suggests the presence of alternative mechanisms other than excitatory synaptic inputs for triggering action potentials (APs) in stellate cells during spatial navigation. Our intracellular recordings show that the hyperpolarization-activated cation current (Ih) allows post-inhibitory-rebound spikes (PIRS) in mEC-LII-SCs. In vivo, strong inhibitory-post-synaptic potentials immediately preceded most APs shortening their delay and enhancing excitability. In vitro experiments showed that inhibition initiated spikes more effectively than excitation and that more dorsal mEC-LII-SCs produced faster and more synchronous spikes. In contrast, PIRS in Layer-II/III pyramidal cells were harder to evoke, voltage-independent, and slower in dorsal mEC. In computational simulations, mEC-LII-SCs morphology and Ih homeostatically regulated the dorso-ventral differences in PIRS timing and most dendrites generated PIRS with a narrow range of stimulus amplitudes. These results suggest inhibitory inputs could mediate the emergence of grid cell firing in a neuronal network. PMID:26965902

Aspiration pneumonia

MedlinePlus

Anaerobic pneumonia; Aspiration of vomitus; Necrotizing pneumonia; Aspiration pneumonitis ... The type of bacteria that caused the pneumonia depends on: Your ... facility, for example) Whether you were recently hospitalized ...

Clinical factors predicting risk for aspiration and respiratory aspiration among patients with Stroke1

PubMed Central

Oliveira, Ana Railka de Souza; Costa, Alice Gabrielle de Sousa; Morais, Huana Carolina Cândido; Cavalcante, Tahissa Frota; Lopes, Marcos Venícios de Oliveira; de Araujo, Thelma Leite

2015-01-01

Objective: to investigate the association of risk factors with the Risk for aspiration nursing diagnosis and respiratory aspiration. Method: cross-sectional study assessing 105 patients with stroke. The instrument used to collect data addressing sociodemographic information, clinical variables and risk factors for Risk for aspiration. The clinical judgments of three expert RNs were used to establish the diagnosis. The relationship between variables and strength of association using Odds Ratio (OR) was verified both in regard to Risk for aspiration and respiratory aspiration. Results: risk for aspiration was present in 34.3% of the patients and aspiration in 30.5%. The following stood out among the risk factors: Dysphagia, Impaired or absent gag reflex, Neurological disorders, and Impaired physical mobility, all of which were statistically associated with Risk for aspiration. Note that patients who develop such a diagnosis were seven times more likely to develop respiratory aspiration. Conclusion: dysphagia, Impaired or absent gag reflex were the best predictors both for Risk for aspiration and respiratory aspiration. PMID:26039291

Pneumonitis and pneumonia after aspiration

PubMed Central

Son, Young Gon; Shin, Jungho

2017-01-01

Aspiration pneumonitis and aspiration pneumonia are clinical syndromes caused by aspiration. These conditions are clinically significant due to their high morbidity and mortality. However, aspiration as a preceding event are often unwitnessed, particularly in cases of asymptomatic or silent aspiration. Furthermore, despite the difference in treatment approaches for managing aspiration pneumonitis and aspiration pneumonia, these two disease entities are often difficult to discriminate from one another, resulting in inappropriate treatment. The use of unclear terminologies hinders the comparability among different studies, making it difficult to produce evidence-based conclusions and practical guidelines. We reviewed the most recent studies to define aspiration, aspiration pneumonitis, and aspiration pneumonia, and to further assess these conditions in terms of incidence and epidemiology, pathophysiology, risk factors, diagnosis, management and treatment, and prevention. PMID:28879323

Combinatorial expression of Lef1, Lhx2, Lhx5, Lhx9, Lmo3, Lmo4, and Prox1 helps to identify comparable subdivisions in the developing hippocampal formation of mouse and chicken

PubMed Central

Abellán, Antonio; Desfilis, Ester; Medina, Loreta

2014-01-01

We carried out a study of the expression patterns of seven developmental regulatory genes (Lef1, Lhx2, Lhx9, Lhx5, Lmo3, Lmo4, and Prox1), in combination with topological position, to identify the medial pallial derivatives, define its major subdivisions, and compare them between mouse and chicken. In both species, the medial pallium is defined as a pallial sector adjacent to the cortical hem and roof plate/choroid tela, showing moderate to strong ventricular zone expression of Lef1, Lhx2, and Lhx9, but not Lhx5. Based on this, the hippocampal formation (indusium griseum, dentate gyrus, Ammon's horn fields, and subiculum), the medial entorhinal cortex, and part of the amygdalo-hippocampal transition area of mouse appeared to derive from the medial pallium. In the chicken, based on the same position and gene expression profile, we propose that the hippocampus (including the V-shaped area), the parahippocampal area (including its caudolateral part), the entorhinal cortex, and the amygdalo-hippocampal transition area are medial pallial derivatives. Moreover, the combinatorial expression of Lef1, Prox1, Lmo4, and Lmo3 allowed the identification of dentate gyrus/CA3-like, CA1/subicular-like, and medial entorhinal-like comparable sectors in mouse and chicken, and point to the existence of mostly conserved molecular networks involved in hippocampal complex development. Notably, while the mouse medial entorhinal cortex derives from the medial pallium (similarly to the hippocampal formation, both being involved in spatial navigation and spatial memory), the lateral entorhinal cortex (involved in processing non-spatial, contextual information) appears to derive from a distinct dorsolateral caudal pallial sector. PMID:25071464

Cayenne aspiration: an unusual type of lower airway foreign-body aspiration

PubMed Central

Lin, Lianjun; Wang, Yuchuan; Zha, Xiankui; Tang, Fei; Lv, Liping; Liu, Xinmin

2014-01-01

Purpose Cayenne aspiration is an unusual type of foreign-body aspiration that is usually misdiagnosed. This article analyzes the clinical features of cayenne aspiration in the lower airway. Patients and methods Clinical data on eight adult patients with cayenne aspiration were retrospectively analyzed. Six were elderly patients. The data were collected from Peking University First Hospital and Anhui Chest Hospital between January 2010 and August 2014. Results The most common symptoms of cayenne aspiration were cough (eight cases, 100%) and sputum (five cases, 62.5%). Only one patient (12.5%) could supply the history of aspiration on his first visit to doctor and was diagnosed definitely without delay. The other seven cases were misdiagnosed as pneumonia and the time to accurate diagnosis was from 1 month to 6 months. The history of aspiration could be recalled after confirmed diagnosis for the other seven cases. The most common presentation shown by chest computed tomography (CT) was pneumonic opacity (eight cases, 100%). The existence of cayenne could not be detected by chest CT in any of the patients. All the patients were diagnosed definitively and managed successfully with flexible bronchoscopy. Cayenne was more often lodged in the right bronchus tree (seven cases, 87.5%), especially the right lower bronchus (four cases, 50%). The segment of cayenne was complete in five cases (62.5%) and scattered in three cases (37.5%). Conclusion The clinical features of cayenne aspiration are usually obscure and nonspecific which may lead to delay in diagnosis. Flexible bronchoscopy is safe and useful for early diagnosis and effective management. PMID:25473273

Consolidation of visual associative long-term memory in the temporal cortex of primates.

PubMed

Miyashita, Y; Kameyama, M; Hasegawa, I; Fukushima, T

1998-01-01

Neuropsychological theories have proposed a critical role for the interaction between the medial temporal lobe and the neocortex in the formation of long-term memory for facts and events, which has often been tested by learning of a series of paired words or figures in humans. We have examined neural mechanisms underlying the memory "consolidation" process by single-unit recording and molecular biological methods in an animal model of a visual pair-association task in monkeys. In our previous studies, we found that long-term associative representations of visual objects are acquired through learning in the neural network of the anterior inferior temporal (IT) cortex. In this article, we propose the hypothesis that limbic neurons undergo rapid modification of synaptic connectivity and provide backward signals that guide the reorganization of neocortical neural circuits. Two experiments tested this hypothesis: (1) we examined the role of the backward connections from the medial temporal lobe to the IT cortex by injecting ibotenic acid into the entorhinal and perirhinal cortices, which provided massive backward projections ipsilaterally to the IT cortex. We found that the limbic lesion disrupted the associative code of the IT neurons between the paired associates, without impairing the visual response to each stimulus. (2) We then tested the first half of this hypothesis by detecting the expression of immediate-early genes in the monkey temporal cortex. We found specific expression of zif268 during the learning of a new set of paired associates in the pair-association task, most intensively in area 36 of the perirhinal cortex. All these results with the visual pair-association task support our hypothesis and demonstrate that the consolidation process, which was first proposed on the basis of clinico-psychological evidence, can now be examined in primates using neurophysiolocical and molecular biological approaches. Copyright 1998 Academic Press.

Contributions of diverse excitatory and inhibitory neurons to recurrent network activity in cerebral cortex.

PubMed

Neske, Garrett T; Patrick, Saundra L; Connors, Barry W

2015-01-21

The recurrent synaptic architecture of neocortex allows for self-generated network activity. One form of such activity is the Up state, in which neurons transiently receive barrages of excitatory and inhibitory synaptic inputs that depolarize many neurons to spike threshold before returning to a relatively quiescent Down state. The extent to which different cell types participate in Up states is still unclear. Inhibitory interneurons have particularly diverse intrinsic properties and synaptic connections with the local network, suggesting that different interneurons might play different roles in activated network states. We have studied the firing, subthreshold behavior, and synaptic conductances of identified cell types during Up and Down states in layers 5 and 2/3 in mouse barrel cortex in vitro. We recorded from pyramidal cells and interneurons expressing parvalbumin (PV), somatostatin (SOM), vasoactive intestinal peptide (VIP), or neuropeptide Y. PV cells were the most active interneuron subtype during the Up state, yet the other subtypes also received substantial synaptic conductances and often generated spikes. In all cell types except PV cells, the beginning of the Up state was dominated by synaptic inhibition, which decreased thereafter; excitation was more persistent, suggesting that inhibition is not the dominant force in terminating Up states. Compared with barrel cortex, SOM and VIP cells were much less active in entorhinal cortex during Up states. Our results provide a measure of functional connectivity of various neuron types in barrel cortex and suggest differential roles for interneuron types in the generation and control of persistent network activity. Copyright © 2015 the authors 0270-6474/15/351089-17$15.00/0.

Perirhinal and Postrhinal, but Not Lateral Entorhinal, Cortices Are Essential for Acquisition of Trace Eyeblink Conditioning

ERIC Educational Resources Information Center

Suter, Eugenie E.; Weiss, Craig; Disterhoft, John F.

2013-01-01

The acquisition of temporal associative tasks such as trace eyeblink conditioning is hippocampus-dependent, while consolidated performance is not. The parahippocampal region mediates much of the input and output of the hippocampus, and perirhinal (PER) and entorhinal (EC) cortices support persistent spiking, a possible mediator of temporal…

Immigrant Aspirations

ERIC Educational Resources Information Center

Portes, Alejandro; And Others

1978-01-01

Examines occupational, income, and educational aspirations among recent Mexican and Cuban immigrants to the United States. Aspirations appear to be set through a rational assessment of past attainments and skills. Reviews implications for immigrants'"dreams of fantasy" when they first arrive in the United States. (Author/AV)

The vomeronasal cortex - afferent and efferent projections of the posteromedial cortical nucleus of the amygdala in mice.

PubMed

Gutiérrez-Castellanos, Nicolás; Pardo-Bellver, Cecília; Martínez-García, Fernando; Lanuza, Enrique

2014-01-01

Most mammals possess a vomeronasal system that detects predominantly chemical signals of biological relevance. Vomeronasal information is relayed to the accessory olfactory bulb (AOB), whose unique cortical target is the posteromedial cortical nucleus of the amygdala. This cortical structure should therefore be considered the primary vomeronasal cortex. In the present work, we describe the afferent and efferent connections of the posteromedial cortical nucleus of the amygdala in female mice, using anterograde (biotinylated dextranamines) and retrograde (Fluorogold) tracers, and zinc selenite as a tracer specific for zinc-enriched (putative glutamatergic) projections. The results show that the posteromedial cortical nucleus of the amygdala is strongly interconnected not only with the rest of the vomeronasal system (AOB and its target structures in the amygdala), but also with the olfactory system (piriform cortex, olfactory-recipient nuclei of the amygdala and entorhinal cortex). Therefore, the posteromedial cortical nucleus of the amygdala probably integrates olfactory and vomeronasal information. In addition, the posteromedial cortical nucleus of the amygdala shows moderate interconnections with the associative (basomedial) amygdala and with the ventral hippocampus, which may be involved in emotional and spatial learning (respectively) induced by chemical signals. Finally, the posteromedial cortical nucleus of the amygdala gives rise to zinc-enriched projections to the ventrolateral septum and the ventromedial striatum (including the medial islands of Calleja). This pattern of intracortical connections (with the olfactory cortex and hippocampus, mainly) and cortico-striatal excitatory projections (with the olfactory tubercle and septum) is consistent with its proposed nature as the primary vomeronasal cortex. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Medial Entorhinal Grid Cells and Head Direction Cells Rotate with a T-Maze More Often During Less Recently Experienced Rotations

PubMed Central

Gupta, Kishan; Beer, Nathan J.; Keller, Lauren A.; Hasselmo, Michael E.

2014-01-01

Prior studies of head direction (HD) cells indicate strong landmark control over the preferred firing direction of these cells, with few studies exhibiting shifts away from local reference frames over time. We recorded spiking activity of grid and HD cells in the medial entorhinal cortex of rats, testing correlations of local environmental cues with the spatial tuning curves of these cells' firing fields as animals performed continuous spatial alternation on a T-maze that shared the boundaries of an open-field arena. The environment was rotated into configurations the animal had either seen or not seen in the past recording week. Tuning curves of both cell types demonstrated commensurate shifts of tuning with T-maze rotations during less recent rotations, more so than recent rotations. This strongly suggests that animals are shifting their reference frame away from the local environmental cues over time, learning to use a different reference frame more likely reliant on distal or idiothetic cues. In addition, grid fields demonstrated varying levels of “fragmentation” on the T-maze. The propensity for fragmentation does not depend on grid spacing and grid score, nor animal trajectory, indicating the cognitive treatment of environmental subcompartments is likely driven by task demands. PMID:23382518

Entorhinal Denervation Induces Homeostatic Synaptic Scaling of Excitatory Postsynapses of Dentate Granule Cells in Mouse Organotypic Slice Cultures

PubMed Central

Vlachos, Andreas; Becker, Denise; Jedlicka, Peter; Winkels, Raphael; Roeper, Jochen; Deller, Thomas

2012-01-01

Denervation-induced changes in excitatory synaptic strength were studied following entorhinal deafferentation of hippocampal granule cells in mature (≥3 weeks old) mouse organotypic entorhino-hippocampal slice cultures. Whole-cell patch-clamp recordings revealed an increase in excitatory synaptic strength in response to denervation during the first week after denervation. By the end of the second week synaptic strength had returned to baseline. Because these adaptations occurred in response to the loss of excitatory afferents, they appeared to be in line with a homeostatic adjustment of excitatory synaptic strength. To test whether denervation-induced changes in synaptic strength exploit similar mechanisms as homeostatic synaptic scaling following pharmacological activity blockade, we treated denervated cultures at 2 days post lesion for 2 days with tetrodotoxin. In these cultures, the effects of denervation and activity blockade were not additive, suggesting that similar mechanisms are involved. Finally, we investigated whether entorhinal denervation, which removes afferents from the distal dendrites of granule cells while leaving the associational afferents to the proximal dendrites of granule cells intact, results in a global or a local up-scaling of granule cell synapses. By using computational modeling and local electrical stimulations in Strontium (Sr2+)-containing bath solution, we found evidence for a lamina-specific increase in excitatory synaptic strength in the denervated outer molecular layer at 3–4 days post lesion. Taken together, our data show that entorhinal denervation results in homeostatic functional changes of excitatory postsynapses of denervated dentate granule cells in vitro. PMID:22403720

Connectivity Reveals Sources of Predictive Coding Signals in Early Visual Cortex During Processing of Visual Optic Flow.

PubMed

Schindler, Andreas; Bartels, Andreas

2017-05-01

Superimposed on the visual feed-forward pathway, feedback connections convey higher level information to cortical areas lower in the hierarchy. A prominent framework for these connections is the theory of predictive coding where high-level areas send stimulus interpretations to lower level areas that compare them with sensory input. Along these lines, a growing body of neuroimaging studies shows that predictable stimuli lead to reduced blood oxygen level-dependent (BOLD) responses compared with matched nonpredictable counterparts, especially in early visual cortex (EVC) including areas V1-V3. The sources of these modulatory feedback signals are largely unknown. Here, we re-examined the robust finding of relative BOLD suppression in EVC evident during processing of coherent compared with random motion. Using functional connectivity analysis, we show an optic flow-dependent increase of functional connectivity between BOLD suppressed EVC and a network of visual motion areas including MST, V3A, V6, the cingulate sulcus visual area (CSv), and precuneus (Pc). Connectivity decreased between EVC and 2 areas known to encode heading direction: entorhinal cortex (EC) and retrosplenial cortex (RSC). Our results provide first evidence that BOLD suppression in EVC for predictable stimuli is indeed mediated by specific high-level areas, in accord with the theory of predictive coding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Contributions of primate prefrontal cortex and medial temporal lobe to temporal-order memory.

PubMed

Naya, Yuji; Chen, He; Yang, Cen; Suzuki, Wendy A

2017-12-19

Neuropsychological and neurophysiological studies have emphasized the role of the prefrontal cortex (PFC) in maintaining information about the temporal order of events or items for upcoming actions. However, the medial temporal lobe (MTL) has also been considered critical to bind individual events or items to their temporal context in episodic memory. Here we characterize the contributions of these brain areas by comparing single-unit activity in the dorsal and ventral regions of macaque lateral PFC (d-PFC and v-PFC) with activity in MTL areas including the hippocampus (HPC), entorhinal cortex, and perirhinal cortex (PRC) as well as in area TE during the encoding phase of a temporal-order memory task. The v-PFC cells signaled specific items at particular time periods of the task. By contrast, MTL cortical cells signaled specific items across multiple time periods and discriminated the items between time periods by modulating their firing rates. Analysis of the temporal dynamics of these signals showed that the conjunctive signal of item and temporal-order information in PRC developed earlier than that seen in v-PFC. During the delay interval between the two cue stimuli, while v-PFC provided prominent stimulus-selective delay activity, MTL areas did not. Both regions of PFC and HPC exhibited an incremental timing signal that appeared to represent the continuous passage of time during the encoding phase. However, the incremental timing signal in HPC was more prominent than that observed in PFC. These results suggest that PFC and MTL contribute to the encoding of the integration of item and timing information in distinct ways.

Acute Intraoperative Pulmonary Aspiration

PubMed Central

Nason, Katie S.

2015-01-01

Synopsis Acute intraoperative aspiration is a potentially fatal complication with significant associated morbidity. Patients undergoing thoracic surgery are at increased risk for anesthesia-related aspiration, largely due to the predisposing conditions associated with this complication. Awareness of the risk factors, predisposing conditions, maneuvers to decrease risk and immediate management options by both the thoracic surgeon and the anesthesia team is imperative to reducing risk and optimizing patient outcomes associated with acute intraoperative pulmonary aspiration. Based on the root-cause analyses that many of the aspiration events can be traced back to provider factors, having an experienced anesthesiologist present for high-risk cases is also critical. PMID:26210926

Pulmonary consequences of aspiration.

PubMed

Terry, P B; Fuller, S D

1989-01-01

Aspiration can lead to serious pulmonary disease and occasionally death. Substances aspirated commonly include bacteria or gastric contents or both, but may be as unusual as diesel oil or a variety of foreign bodies. Pulmonary symptoms range from a subtle cough, wheezing, or hoarseness to severe dyspnea or asphyxiation. We discuss the mechanism of pulmonary disease caused by aspiration as well as the appropriate treatment.

DNA targeting of rhinal cortex D2 receptor protein reversibly blocks learning of cues that predict reward.

PubMed

Liu, Zheng; Richmond, Barry J; Murray, Elisabeth A; Saunders, Richard C; Steenrod, Sara; Stubblefield, Barbara K; Montague, Deidra M; Ginns, Edward I

2004-08-17

When schedules of several operant trials must be successfully completed to obtain a reward, monkeys quickly learn to adjust their behavioral performance by using visual cues that signal how many trials have been completed and how many remain in the current schedule. Bilateral rhinal (perirhinal and entorhinal) cortex ablations irreversibly prevent this learning. Here, we apply a recombinant DNA technique to investigate the role of dopamine D2 receptor in rhinal cortex for this type of learning. Rhinal cortex was injected with a DNA construct that significantly decreased D2 receptor ligand binding and temporarily produced the same profound learning deficit seen after ablation. However, unlike after ablation, the D2 receptor-targeted, DNA-treated monkeys recovered cue-related learning after 11-19 weeks. Injecting a DNA construct that decreased N-methyl-d-aspartate but not D2 receptor ligand binding did not interfere with learning associations between the cues and the schedules. A second D2 receptor-targeted DNA treatment administered after either recovery from a first D2 receptor-targeted DNA treatment (one monkey), after N-methyl-d-aspartate receptor-targeted DNA treatment (two monkeys), or after a vector control treatment (one monkey) also induced a learning deficit of similar duration. These results suggest that the D2 receptor in primate rhinal cortex is essential for learning to relate the visual cues to the schedules. The specificity of the receptor manipulation reported here suggests that this approach could be generalized in this or other brain pathways to relate molecular mechanisms to cognitive functions.

DNA targeting of rhinal cortex D2 receptor protein reversibly blocks learning of cues that predict reward

PubMed Central

Liu, Zheng; Richmond, Barry J.; Murray, Elisabeth A.; Saunders, Richard C.; Steenrod, Sara; Stubblefield, Barbara K.; Montague, Deidra M.; Ginns, Edward I.

2004-01-01

When schedules of several operant trials must be successfully completed to obtain a reward, monkeys quickly learn to adjust their behavioral performance by using visual cues that signal how many trials have been completed and how many remain in the current schedule. Bilateral rhinal (perirhinal and entorhinal) cortex ablations irreversibly prevent this learning. Here, we apply a recombinant DNA technique to investigate the role of dopamine D2 receptor in rhinal cortex for this type of learning. Rhinal cortex was injected with a DNA construct that significantly decreased D2 receptor ligand binding and temporarily produced the same profound learning deficit seen after ablation. However, unlike after ablation, the D2 receptor-targeted, DNA-treated monkeys recovered cue-related learning after 11–19 weeks. Injecting a DNA construct that decreased N-methyl-d-aspartate but not D2 receptor ligand binding did not interfere with learning associations between the cues and the schedules. A second D2 receptor-targeted DNA treatment administered after either recovery from a first D2 receptor-targeted DNA treatment (one monkey), after N-methyl-d-aspartate receptor-targeted DNA treatment (two monkeys), or after a vector control treatment (one monkey) also induced a learning deficit of similar duration. These results suggest that the D2 receptor in primate rhinal cortex is essential for learning to relate the visual cues to the schedules. The specificity of the receptor manipulation reported here suggests that this approach could be generalized in this or other brain pathways to relate molecular mechanisms to cognitive functions. PMID:15302926

Sequential voluntary cough and aspiration or aspiration risk in Parkinson's disease.

PubMed

Hegland, Karen Wheeler; Okun, Michael S; Troche, Michelle S

2014-08-01

Disordered swallowing, or dysphagia, is almost always present to some degree in people with Parkinson's disease (PD), either causing aspiration or greatly increasing the risk for aspiration during swallowing. This likely contributes to aspiration pneumonia, a leading cause of death in this patient population. Effective airway protection is dependent upon multiple behaviors, including cough and swallowing. Single voluntary cough function is disordered in people with PD and dysphagia. However, the appropriate response to aspirate material is more than one cough, or sequential cough. The goal of this study was to examine voluntary sequential coughing in people with PD, with and without dysphagia. Forty adults diagnosed with idiopathic PD produced two trials of sequential voluntary cough. The cough airflows were obtained using pneumotachograph and facemask and subsequently digitized and recorded. All participants received a modified barium swallow study as part of their clinical care, and the worst penetration-aspiration score observed was used to determine whether the patient had dysphagia. There were significant differences in the compression phase duration, peak expiratory flow rates, and amount of air expired of the sequential cough produced by participants with and without dysphagia. The presence of dysphagia in people with PD is associated with disordered cough function. Sequential cough, which is important in removing aspirate material from large- and smaller-diameter airways, is also impaired in people with PD and dysphagia compared with those without dysphagia. There may be common neuroanatomical substrates for cough and swallowing impairment in PD leading to the co-occurrence of these dysfunctions.

Medial reward and lateral non-reward orbitofrontal cortex circuits change in opposite directions in depression.

PubMed

Cheng, Wei; Rolls, Edmund T; Qiu, Jiang; Liu, Wei; Tang, Yanqing; Huang, Chu-Chung; Wang, XinFa; Zhang, Jie; Lin, Wei; Zheng, Lirong; Pu, JunCai; Tsai, Shih-Jen; Yang, Albert C; Lin, Ching-Po; Wang, Fei; Xie, Peng; Feng, Jianfeng

2016-12-01

The first brain-wide voxel-level resting state functional connectivity neuroimaging analysis of depression is reported, with 421 patients with major depressive disorder and 488 control subjects. Resting state functional connectivity between different voxels reflects correlations of activity between those voxels and is a fundamental tool in helping to understand the brain regions with altered connectivity and function in depression. One major circuit with altered functional connectivity involved the medial orbitofrontal cortex Brodmann area 13, which is implicated in reward, and which had reduced functional connectivity in depression with memory systems in the parahippocampal gyrus and medial temporal lobe, especially involving the perirhinal cortex Brodmann area 36 and entorhinal cortex Brodmann area 28. The Hamilton Depression Rating Scale scores were correlated with weakened functional connectivity of the medial orbitofrontal cortex Brodmann area 13. Thus in depression there is decreased reward-related and memory system functional connectivity, and this is related to the depressed symptoms. The lateral orbitofrontal cortex Brodmann area 47/12, involved in non-reward and punishing events, did not have this reduced functional connectivity with memory systems. Second, the lateral orbitofrontal cortex Brodmann area 47/12 had increased functional connectivity with the precuneus, the angular gyrus, and the temporal visual cortex Brodmann area 21. This enhanced functional connectivity of the non-reward/punishment system (Brodmann area 47/12) with the precuneus (involved in the sense of self and agency), and the angular gyrus (involved in language) is thus related to the explicit affectively negative sense of the self, and of self-esteem, in depression. A comparison of the functional connectivity in 185 depressed patients not receiving medication and 182 patients receiving medication showed that the functional connectivity of the lateral orbitofrontal cortex Brodmann

High Aspirations but Low Progression: The Science Aspirations-Careers Paradox amongst Minority Ethnic Students

ERIC Educational Resources Information Center

DeWitt, Jennifer; Archer, Louise; Osborne, Jonathan; Dillon, Justin; Willis, Beatrice; Wong, Billy

2011-01-01

Students' interest in studying science and their aspirations to pursue science-related careers is a topic of global concern. In this paper, a set of data gathered for the initial phase of the 5-year study of Science Aspirations and Careers: Age 10-14 (the ASPIRES project) is presented. In the initial phase of this project, a questionnaire…

Activation of mitogen-activated protein kinase/extracellular signal-regulated kinase in hippocampal circuitry is required for consolidation and reconsolidation of recognition memory.

PubMed

Kelly, Aine; Laroche, Serge; Davis, Sabrina

2003-06-15

Consolidation and reconsolidation of long-term memory have been shown to be dependent on the synthesis of new proteins, but the specific molecular mechanisms underlying these events remain to be elucidated. The mitogen-activated protein kinase (MAPK) pathway can trigger genomic responses in neurons, leading to changes in protein synthesis, and several studies have identified its pivotal role in synaptic plasticity and long-term memory formation. In this study, we analyze the involvement of this pathway in the consolidation and reconsolidation of long-term recognition memory, using an object recognition task. We show that inhibition of the MAPK pathway by intracerebroventricular injection of the MEK [MAPK/extracellular signal-regulated kinase (ERK)] inhibitor UO126 blocks consolidation of object recognition memory but does not affect short-term memory. Brain regions of the entorhinal cortex-hippocampal circuitry were analyzed for ERK activation, and it was shown that consolidation of recognition memory was associated with increased phosphorylation of ERK in the dentate gyrus and entorhinal cortex, although total expression of ERK was unchanged. We also report that inhibition of the MAPK pathway blocks reconsolidation of recognition memory, and this was shown to be dependent on reactivation of the memory trace by brief reexposure to the objects. In addition, reconsolidation of memory was associated with an increase in the phosphorylation of ERK in entorhinal cortex and CA1. In summary, our data show that the MAPK kinase pathway is required for both consolidation and reconsolidation of long-term recognition memory, and that this is associated with hyperphosphorylation of ERK in different subregions of the entorhinal cortex-hippocampal circuitry.

Evaluating the Small-World-Ness of a Sampled Network: Functional Connectivity of Entorhinal-Hippocampal Circuitry

NASA Astrophysics Data System (ADS)

She, Qi; Chen, Guanrong; Chan, Rosa H. M.

2016-02-01

The amount of publicly accessible experimental data has gradually increased in recent years, which makes it possible to reconsider many longstanding questions in neuroscience. In this paper, an efficient framework is presented for reconstructing functional connectivity using experimental spike-train data. A modified generalized linear model (GLM) with L1-norm penalty was used to investigate 10 datasets. These datasets contain spike-train data collected from the entorhinal-hippocampal region in the brains of rats performing different tasks. The analysis shows that entorhinal-hippocampal network of well-trained rats demonstrated significant small-world features. It is found that the connectivity structure generated by distance-dependent models is responsible for the observed small-world features of the reconstructed networks. The models are utilized to simulate a subset of units recorded from a large biological neural network using multiple electrodes. Two metrics for quantifying the small-world-ness both suggest that the reconstructed network from the sampled nodes estimates a more prominent small-world-ness feature than that of the original unknown network when the number of recorded neurons is small. Finally, this study shows that it is feasible to adjust the estimated small-world-ness results based on the number of neurons recorded to provide a more accurate reference of the network property.

Spiking Neurons in a Hierarchical Self-Organizing Map Model Can Learn to Develop Spatial and Temporal Properties of Entorhinal Grid Cells and Hippocampal Place Cells

PubMed Central

Pilly, Praveen K.; Grossberg, Stephen

2013-01-01

Medial entorhinal grid cells and hippocampal place cells provide neural correlates of spatial representation in the brain. A place cell typically fires whenever an animal is present in one or more spatial regions, or places, of an environment. A grid cell typically fires in multiple spatial regions that form a regular hexagonal grid structure extending throughout the environment. Different grid and place cells prefer spatially offset regions, with their firing fields increasing in size along the dorsoventral axes of the medial entorhinal cortex and hippocampus. The spacing between neighboring fields for a grid cell also increases along the dorsoventral axis. This article presents a neural model whose spiking neurons operate in a hierarchy of self-organizing maps, each obeying the same laws. This spiking GridPlaceMap model simulates how grid cells and place cells may develop. It responds to realistic rat navigational trajectories by learning grid cells with hexagonal grid firing fields of multiple spatial scales and place cells with one or more firing fields that match neurophysiological data about these cells and their development in juvenile rats. The place cells represent much larger spaces than the grid cells, which enable them to support navigational behaviors. Both self-organizing maps amplify and learn to categorize the most frequent and energetic co-occurrences of their inputs. The current results build upon a previous rate-based model of grid and place cell learning, and thus illustrate a general method for converting rate-based adaptive neural models, without the loss of any of their analog properties, into models whose cells obey spiking dynamics. New properties of the spiking GridPlaceMap model include the appearance of theta band modulation. The spiking model also opens a path for implementation in brain-emulating nanochips comprised of networks of noisy spiking neurons with multiple-level adaptive weights for controlling autonomous adaptive robots

Contribution of Genoarchitecture to Understanding Hippocampal Evolution and Development.

PubMed

Medina, Loreta; Abellán, Antonio; Desfilis, Ester

2017-01-01

The hippocampal formation is a highly conserved structure of the medial pallium that works in association with the entorhinal cortex, playing a key role in memory formation and spatial navigation. Although it has been described in several vertebrates, the presence of comparable subdivisions across species remained unclear. This panorama has started to change in recent years thanks to the identification of some of the genes that regulate the development of the hippocampal formation in the mouse and help to delineate its subdivisions based on molecular features. Some of these genes have been used to try to identify subdivisions in chicken and lizards comparable to those of the mammalian hippocampal formation and the entorhinal cortex. Here, we review some of these data, which suggest the existence of fields comparable to the dentate gyrus, CA3, CA1, subiculum, as well as medial and lateral parts of the entorhinal cortex in all amniotes. We also analyze available data suggesting the existence of serial connections between these fields, speculate on the possible existence of auto-associative loops in CA3, and discuss general principles governing the formation of the connections. © 2017 S. Karger AG, Basel.

Mapping parahippocampal systems for recognition and recency memory in the absence of the rat hippocampus

PubMed Central

Kinnavane, L; Amin, E; Horne, M; Aggleton, J P

2014-01-01

The present study examined immediate-early gene expression in the perirhinal cortex of rats with hippocampal lesions. The goal was to test those models of recognition memory which assume that the perirhinal cortex can function independently of the hippocampus. The c-fos gene was targeted, as its expression in the perirhinal cortex is strongly associated with recognition memory. Four groups of rats were examined. Rats with hippocampal lesions and their surgical controls were given either a recognition memory task (novel vs. familiar objects) or a relative recency task (objects with differing degrees of familiarity). Perirhinal Fos expression in the hippocampal-lesioned groups correlated with both recognition and recency performance. The hippocampal lesions, however, had no apparent effect on overall levels of perirhinal or entorhinal cortex c-fos expression in response to novel objects, with only restricted effects being seen in the recency condition. Network analyses showed that whereas the patterns of parahippocampal interactions were differentially affected by novel or familiar objects, these correlated networks were not altered by hippocampal lesions. Additional analyses in control rats revealed two modes of correlated medial temporal activation. Novel stimuli recruited the pathway from the lateral entorhinal cortex (cortical layer II or III) to hippocampal field CA3, and thence to CA1. Familiar stimuli recruited the direct pathway from the lateral entorhinal cortex (principally layer III) to CA1. The present findings not only reveal the independence from the hippocampus of some perirhinal systems associated with recognition memory, but also show how novel stimuli engage hippocampal subfields in qualitatively different ways from familiar stimuli. PMID:25264133

Differential regulation of axon outgrowth and reinnervation by neurotrophin-3 and neurotrophin-4 in the hippocampal formation.

PubMed

Hechler, Daniel; Boato, Francesco; Nitsch, Robert; Hendrix, Sven

2010-08-01

In this study, we investigated the hypothesis whether neurotrophins have a differential influence on neurite growth from the entorhinal cortex depending on the presence or absence of hippocampal target tissue. We investigated organotypic brain slices derived from the entorhinal-hippocampal system to analyze the effects of endogenous and recombinant neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) on neurite outgrowth and reinnervation. In the reinnervation assay, entorhinal cortex explants of transgenic mice expressing enhanced green fluorescent protein (EGFP) were co-cultured with wild-type hippocampi under the influence of recombinant NT-3 and NT-4 (500 ng/ml). Both recombinant NT-3 and NT-4 significantly increased the growth of EGFP+ nerve fibers into the target tissue. Consistently, reinnervation of the hippocampi of NT-4(-/-) and NT-3(+/-)NT-4(-/-) mice was substantially reduced. In contrast, the outgrowth assay did not exhibit reduction in axon outgrowth of NT-4(-/-) or NT-3(+/-)NT-4(-/-) cortex explants, while the application of recombinant NT-3 (500 ng/ml) induced a significant increase in the neurite extension of cortex explants. Recombinant NT-4 had no effect. In summary, only recombinant NT-3 stimulates axon outgrowth from cortex explants, while both endogenous and recombinant NT-3 and NT-4 synergistically promote reinnervation of the denervated hippocampus. These results suggest that endogenous and exogenous NT-3 and NT-4 differentially influence neurite growth depending on the presence or absence of target tissue.

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatiotemporal Network Dynamics.

PubMed

Hendrickson, Phillip J; Yu, Gene J; Song, Dong; Berger, Theodore W

2016-01-01

This paper describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust nonrandom pattern of spiking best described as a spatiotemporal "clustering." To identify the network property or properties responsible for generating such firing "clusters," we progressively eliminated from the model key mechanisms, such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatiotemporal distribution of clustered

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatio-Temporal Network Dynamics

PubMed Central

Hendrickson, Phillip J.; Yu, Gene J.; Song, Dong; Berger, Theodore W.

2016-01-01

Goal This manuscript describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. Methods The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust, non-random pattern of spiking best described as spatio-temporal “clustering”. To identify the network property or properties responsible for generating such firing “clusters”, we progressively eliminated from the model key mechanisms such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Conclusion Findings conclusively identified topographical organization of inputs as the key element responsible for generating

Aspiration and Non-Aspiration Pneumonia in Hospitalized Children With Neurologic Impairment.

PubMed

Thomson, Joanna; Hall, Matt; Ambroggio, Lilliam; Stone, Bryan; Srivastava, Rajendu; Shah, Samir S; Berry, Jay G

2016-02-01

Children with neurologic impairment (NI) are commonly hospitalized for different types of pneumonia, including aspiration pneumonia. We sought to compare hospital management and outcomes of children with NI diagnosed with aspiration versus nonaspiration pneumonia. A retrospective study of 27 455 hospitalized children aged 1 to 18 years with NI diagnosed with pneumonia from 2007 to 2012 at 40 children's hospitals in the Pediatric Health Information System database. The primary exposure was pneumonia type, classified as aspiration or nonaspiration. Outcomes were complications (eg, acute respiratory failure) and hospital utilization (eg, length of stay, 30-day readmission). Multivariable regression was used to assess the association between pneumonia type and outcomes, adjusting for NI type, comorbid conditions, and other characteristics. In multivariable analysis, the 9.7% of children diagnosed with aspiration pneumonia experienced more complications than children with nonaspiration pneumonia (34.0% vs 15.2%, adjusted odds ratio [aOR] 1.2 (95% confidence interval [CI] 1.1-1.3). Children with aspiration pneumonia had significantly longer length of stay (median 5 vs 3 days; ratio of means 1.2; 95% CI 1.2-1.3); more ICU transfers (4.3% vs 1.5%; aOR 1.4; 95% CI 1.1-1.9); greater hospitalization costs (median $11 594 vs $5162; ratio of means 1.2; 95% CI 1.2-1.3); and more 30-day readmissions (17.4% vs 6.8%; aOR 1.3; 95% CI 1.2-1.5). Hospitalized children with NI diagnosed with aspiration pneumonia have more complications and use more hospital resources than when diagnosed with nonaspiration pneumonia. Additional investigation is needed to understand the reasons for these differences. Copyright © 2016 by the American Academy of Pediatrics.

Sequential Voluntary Cough and Aspiration or Aspiration Risk in Parkinson’s Disease

PubMed Central

Hegland, Karen Wheeler; Okun, Michael S.; Troche, Michelle S.

2015-01-01

Background Disordered swallowing, or dysphagia, is almost always present to some degree in people with Parkinson’s disease (PD), either causing aspiration or greatly increasing the risk for aspiration during swallowing. This likely contributes to aspiration pneumonia, a leading cause of death in this patient population. Effective airway protection is dependent upon multiple behaviors, including cough and swallowing. Single voluntary cough function is disordered in people with PD and dysphagia. However, the appropriate response to aspirate material is more than one cough, or sequential cough. The goal of this study was to examine voluntary sequential coughing in people with PD, with and without dysphagia. Methods Forty adults diagnosed with idiopathic PD produced two trials of sequential voluntary cough. The cough airflows were obtained using pneumotachograph and facemask and subsequently digitized and recorded. All participants received a modified barium swallow study as part of their clinical care, and the worst penetration–aspiration score observed was used to determine whether the patient had dysphagia. Results There were significant differences in the compression phase duration, peak expiratory flow rates, and amount of air expired of the sequential cough produced by participants with and without dysphagia. Conclusions The presence of dysphagia in people with PD is associated with disordered cough function. Sequential cough, which is important in removing aspirate material from large- and smaller-diameter airways, is also impaired in people with PD and dysphagia compared with those without dysphagia. There may be common neuroanatomical substrates for cough and swallowing impairment in PD leading to the co-occurrence of these dysfunctions. PMID:24792231

Entorhinal cortical defects in Tg2576 mice are present as early as 2–4 months of age

PubMed Central

Duffy, Áine M.; Morales-Corraliza, Jose; Bermudez-Hernandez, Keria M.; Schaner, Michael J.; Magagna-Poveda, Alejandra; Mathews, Paul M.; Scharfman, Helen E.

2014-01-01

The entorhinal cortex (EC) is one of the first brain areas to display neuropathology in Alzheimer’s disease (AD). A mouse model which simulates amyloid-β (Aβ) neuropathology, the Tg2576 mouse, was used to address these early changes. Here we show EC abnormalities occur in 2–4 month-old Tg2576 mice, an age prior to β-amyloid deposition and where previous studies suggest that there are few behavioral impairments. First we show, using sandwich ELISA, that soluble human Aβ40 and Aβ42 are detectable in the EC of 2-month-old Tg2576 mice prior to β-amyloid deposition. We then demonstrate that 2–4 month-old Tg2576 mice are impaired at object placement, an EC-dependent cognitive task. Next we show that defects in NeuN expression and myelin uptake occur in the superficial layers of the EC in 2–4-month-old Tg2576 mice. In slices from Tg2576 mice that contained the EC, there were repetitive field potentials evoked by a single stimulus to the underlying white matter, and a greater response to reduced extracellular magnesium ([Mg2+]o), suggesting increased excitability. However, deep layer neurons in Tg2576 mice had longer latencies to antidromic activation than wild type mice. The results show changes in the EC at early ages, and suggest that altered excitability occurs before extensive plaque pathology. PMID:25109765

Ultrasound-guided fine-needle aspiration biopsy of clinically suspicious thyroid nodules with an automatic aspirator: a novel technique.

PubMed

Nagarajah, James; Sheu-Grabellus, Sien-Yi; Farahati, Jamshid; Kamruddin, Kamer A; Bockisch, Andreas; Schmid, Kurt Werner; Görges, Rainer

2012-07-01

Fine-needle aspiration biopsy (FNAB) is a simple technique for the investigation of suspicious thyroid nodules. However, low success rates are reported in the literature. The aim of this prospective study was to compare the clinical performance and impact of an automatic aspirator, referred to here as Aspirator 3, to those of the manual technique for the FNAB of clinically suspicious thyroid nodules. One hundred nine consecutive patients with 121 clinically suspicious thyroid nodules underwent a biopsy twice of the same site with the clinically approved Aspirator 3 and with the manual technique. The number of follicular cell formations and the total number of follicular cells in the aspirate were counted using the ThinPrep® method. With the Aspirator 3, the total number and the mean number of extracted cell formations were significantly higher than the values achieved with the manual technique (total: 3222 vs. 1951, p=0.02; mean: 27 vs. 16). The total number of cells that were biopsied was also higher when the Aspirator 3 was utilized (47,480 vs. 23,080, p=0.005). Overall, the Aspirator 3 was superior in 65 biopsies, and the manual technique was superior in 39 biopsies. In terms of cell formations and the total number of cells aspirated, the Aspirator 3 was superior to the manual technique. Further, the Aspirator 3 was more convenient to use and had a greater precision in needle guidance.

Schizophrenia - A disturbance of signal interaction between the entorhinal cortex and the dentate gyrus? The contribution of experimental dibenamine psychosis to the pathogenesis of schizophrenia: A hypothesis.

PubMed

Arnold, O H

1999-01-01

In addition to the existence of complex memory (similar to the implicit nondeclarative memory of Squire), the existence of a phylogenetically old apparatus of a memory of situations (SMA) is supposed, which is to some extent comparable with the declarative memory of Squire. During actual sensory information the SMA generates a general frame and forms a general 'mark', indicating whether a given information has its origin inside or outside the body, and whether it is new or known. The procedure of this marking process can be explained as the time-depending arrest of a copy of the actual original information-transporting signal 'shower'; this copy must last until the feedback from thalamocortical centers indicates the termination of the processing of the original signal showers. The arrest of the shower copies is the performance of neuronal networks of the entorhinal cortex (EC) and the gyrus dentatus (GD). The psychopathological and biochemical analyses of experimental dibenamine psychosis show a different effect of dibenamine on the noradrenaline (NA) receptors of the EC and GD, respectively: these effects are responsible for the repeated perception cycles of a single situation. N,N-Dibencylamine blocks the postsynaptic alpha(1)-receptors of the EC without influencing the beta-receptors of the GD. Thus the interaction between EC and GD is changed: instead of new scenes, perceptions that have just been experienced get repeated presence and the quality of familiarity. The prolonged arrest of shower copies simultaneously blocks the entrance of new signal showers from the EC to the GD. No information-transporting signal showers can come in as long as the arrest lasts. In case of a disturbance in NA-dependent actions within the EC and the GD, the duration of arrest of information-transporting signal showers is shortened. Thus the formal frame of experience receives the quality of novelty instead of familiarity, and in addition the qualities of uncertainty, vagueness

[Quantitative evaluation of inhibitory effects of epileptic spikes on theta rhythms in the network of hippocampal CA3 and entorhinal cortex in patients with temporal lobe epilepsy].

PubMed

Ge, Man-Ling; Guo, Jun-Dan; Chen, Sheng-Hua; Zhang, Ji-Chang; Fu, Xiao-Xuan; Chen, Yu-Min

2017-02-25

Epileptic spike is an indicator of hyper-excitability and hyper-synchrony in the neural networks. The inhibitory effects of spikes on theta rhythms (4-8 Hz) might be helpful to understand the mechanism of epileptic damage on the cognitive functions. To quantitatively evaluate the inhibitory effects of spikes on theta rhythms, intracerebral electroencephalogram (EEG) recordings with both sporadic spikes (SSs) and spike-free transient period between adjacent spikes were selected in 4 patients in the status of rapid eyes movement (REM) sleep with temporal lobe epilepsy (TLE) under the pre-surgical monitoring. The electrodes of hippocampal CA3 and entorhinal cortex (EC) were employed, since CA3 and EC built up one of key loops to investigate cognition and epilepsy. These SSs occurred only in CA3, only in EC, or in both CA3 and EC synchronously. Theta power was respectively estimated around SSs and during the spike-free transient period by Gabor wavelet transform and Hilbert transform. The intermittent extent was then estimated to represent for the loss of theta rhythms during the spike-free transient period. The following findings were obtained: (1) The prominent rhythms were in theta frequency band; (2) The spikes could transiently reduce theta power, and the inhibitory effect was severer around SSs in both CA3 and EC synchronously than that around either SSs only in EC or SSs only in CA3; (3) During the spike-free transient period, theta rhythms were interrupted with the intermittent theta rhythms left and theta power level continued dropping, implying the inhibitory effect was sustained. Additionally, the intermittent extent of theta rhythms was converged to the inhibitory extent around SSs; (4) The average theta power level during the spike-free transient period might not be in line with the inhibitory extent of theta rhythms around SSs. It was concluded that the SSs had negative effects on theta rhythms transiently and directly, the inhibitory effects aroused by

[Foreign body aspiration in children].

PubMed

Cohen, Shlomo; Goldberg, Shmuel; Springer, Chaim; Avital, Avraham; Picard, Elie

2015-03-01

Foreign body (FB) aspiration occurs mainly in children under 3 years of age and is one of the most frequent causes of accidental death under 12 months of age. The increased risk of FB aspiration in children is due to the different structure of the pharynx and the upper airways compared to adults. In addition, children have an immature swallowing mechanism and they most commonly aspirate food stuffs. FB aspiration is usually a sudden and dramatic event when the child feels that he is suffocating or choking. After the acute event, the clinical presentation widely ranges from severe respiratory distress to the most minimal symptoms. Bronchoscopy is the best diagnostic and therapeutic modality for FB inhalation. Prevention and rapid diagnosis can be lifesaving. In 2010, the American Academy of Pediatrics published a position paper on prevention of FB aspiration. The association calls for more proactive preventative measures to protect children from FB aspiration and to prevent mortality and morbidity. These include: 1. Raising awareness of parents and caregivers to supervise children and create a safe environment for them. 2. Promoting legislation and enforcing regulations that will prevent dangerous products being sold for children. 3. Changing the design of products, especially food products and toys, that will reduce the risks of choking. In this overview we will show the principles of diagnosis of FB aspiration and a flow chart including when flexible or rigid bronchoscopy is required.

Aspirations of Latina Adolescent Suicide Attempters

ERIC Educational Resources Information Center

Hausmann-Stabile, Carolina; Gulbas, Lauren; Zayas, Luis H.

2013-01-01

Parents' aspirations and expectations are communicated to their offspring. Children internalize their parents' aspirations and accept some of the expectations while rejecting others, all part of the developmental process and identity-consolidation. When the aspirations and expectations of youth and parents are incongruent, the outcomes…

Coordinated learning of grid cell and place cell spatial and temporal properties: multiple scales, attention and oscillations.

PubMed

Grossberg, Stephen; Pilly, Praveen K

2014-02-05

A neural model proposes how entorhinal grid cells and hippocampal place cells may develop as spatial categories in a hierarchy of self-organizing maps (SOMs). The model responds to realistic rat navigational trajectories by learning both grid cells with hexagonal grid firing fields of multiple spatial scales, and place cells with one or more firing fields, that match neurophysiological data about their development in juvenile rats. Both grid and place cells can develop by detecting, learning and remembering the most frequent and energetic co-occurrences of their inputs. The model's parsimonious properties include: similar ring attractor mechanisms process linear and angular path integration inputs that drive map learning; the same SOM mechanisms can learn grid cell and place cell receptive fields; and the learning of the dorsoventral organization of multiple spatial scale modules through medial entorhinal cortex to hippocampus (HC) may use mechanisms homologous to those for temporal learning through lateral entorhinal cortex to HC ('neural relativity'). The model clarifies how top-down HC-to-entorhinal attentional mechanisms may stabilize map learning, simulates how hippocampal inactivation may disrupt grid cells, and explains data about theta, beta and gamma oscillations. The article also compares the three main types of grid cell models in the light of recent data.

Aspiring to physical health: The role of aspirations for physical health in facilitating long-term tobacco abstinence

PubMed Central

Niemiec, Christopher P.; Ryan, Richard M.; Deci, Edward L.; Williams, Geoffrey C.

2009-01-01

Objective To assess aspirations for physical health over 18 months. To examine whether maintained importance of aspirations for physical health mediated and/or moderated the effect of an intensive intervention on long-term tobacco abstinence. Methods Participants were randomly assigned to an intervention based on self-determination theory or to community care, and provided data at baseline and at 18 and 30 months post-randomization. Results Aspirations for physical health were better maintained over 18 months among participants in the intervention (mean change = .05), relative to community care (mean change = -.13), t = 2.66, p < .01. Maintained importance of aspirations for physical health partially mediated the treatment condition effects on seven-day point prevalence tobacco abstinence (z′ = 1.68, p < .01) and the longest number of days not smoking (z′ = 2.16, p < .01), and interacted with treatment condition to facilitate the longest number of days not smoking (β = .08, p < .05). Conclusion Maintained importance of aspirations for physical health facilitated tobacco abstinence. Practice implications Smokers may benefit from discussing aspirations for physical health within autonomy-supportive interventions. Patients may benefit from discussing aspirations during counseling about therapeutic lifestyle change and medication use. PMID:18838243

Aspiring to physical health: the role of aspirations for physical health in facilitating long-term tobacco abstinence.

PubMed

Niemiec, Christopher P; Ryan, Richard M; Deci, Edward L; Williams, Geoffrey C

2009-02-01

To assess aspirations for physical health over 18 months. To examine whether maintained importance of aspirations for physical health mediated and/or moderated the effect of an intensive intervention on long-term tobacco abstinence. Participants were randomly assigned to an intervention based on self-determination theory or to community care, and provided data at baseline and at 18 and 30 months post-randomization. Aspirations for physical health were better maintained over 18 months among participants in the intervention (mean change=.05), relative to community care (mean change=-.13), t=2.66, p<.01. Maintained importance of aspirations for physical health partially mediated the treatment condition effects on seven-day point prevalence tobacco abstinence (z'=1.68, p<.01) and the longest number of days not smoking (z'=2.16, p<.01), and interacted with treatment condition to facilitate the longest number of days not smoking (beta=.08, p<.05). Maintained importance of aspirations for physical health facilitated tobacco abstinence. Smokers may benefit from discussing aspirations for physical health within autonomy-supportive interventions. Patients may benefit from discussing aspirations during counseling about therapeutic lifestyle change and medication use.

Extensive cytotoxic lesions of the rat retrosplenial cortex reveal consistent deficits on tasks that tax allocentric spatial memory.

PubMed

Vann, Seralynne D; Aggleton, John P

2002-02-01

Despite the connections of the retrosplenial cortex strongly suggesting a role in spatial memory, the lesion data to date have been equivocal. Whether subjects are impaired after retrosplenial lesions seems to depend on whether the lesions were aspirative or excitotoxic, with the latter failing to produce an impairment. A shortcoming of previous excitotoxic lesion studies is that they spared the most caudal part of the retrosplenial cortex. The present study thus used rats with extensive neurotoxic lesions of the retrosplenial cortex that encompassed the entire rostrocaudal extent of this region. These rats were consistently impaired on several tests that tax allocentric memory. In contrast, they were unimpaired on an egocentric discrimination task. Although the lesions did not appear to affect object recognition, clear deficits were found for an object-in-place discrimination. The present study not only demonstrates a role for the retrosplenial cortex in allocentric spatial memory, but also explains why previous excitotoxic lesions have failed to detect any deficits.

Computer-aided classification of Alzheimer's disease based on support vector machine with combination of cerebral image features in MRI

NASA Astrophysics Data System (ADS)

Jongkreangkrai, C.; Vichianin, Y.; Tocharoenchai, C.; Arimura, H.; Alzheimer's Disease Neuroimaging Initiative

2016-03-01

Several studies have differentiated Alzheimer's disease (AD) using cerebral image features derived from MR brain images. In this study, we were interested in combining hippocampus and amygdala volumes and entorhinal cortex thickness to improve the performance of AD differentiation. Thus, our objective was to investigate the useful features obtained from MRI for classification of AD patients using support vector machine (SVM). T1-weighted MR brain images of 100 AD patients and 100 normal subjects were processed using FreeSurfer software to measure hippocampus and amygdala volumes and entorhinal cortex thicknesses in both brain hemispheres. Relative volumes of hippocampus and amygdala were calculated to correct variation in individual head size. SVM was employed with five combinations of features (H: hippocampus relative volumes, A: amygdala relative volumes, E: entorhinal cortex thicknesses, HA: hippocampus and amygdala relative volumes and ALL: all features). Receiver operating characteristic (ROC) analysis was used to evaluate the method. AUC values of five combinations were 0.8575 (H), 0.8374 (A), 0.8422 (E), 0.8631 (HA) and 0.8906 (ALL). Although “ALL” provided the highest AUC, there were no statistically significant differences among them except for “A” feature. Our results showed that all suggested features may be feasible for computer-aided classification of AD patients.

Automatic Clustering and Thickness Measurement of Anatomical Variants of the Human Perirhinal Cortex

PubMed Central

Xie, Long; Pluta, John; Wang, Hongzhi; Das, Sandhitsu R.; Mancuso, Lauren; Kliot, Dasha; Avants, Brian B.; Ding, Song-Lin; Wolk, David A.; Yushkevich, Paul A.

2015-01-01

The entorhinal cortex (ERC) and the perirhinal cortex (PRC) are subregions of the medial temporal lobe (MTL) that play important roles in episodic memory representations, as well as serving as a conduit between other neocortical areas and the hippocampus. They are also the sites where neuronal damage first occurs in Alzheimer’s disease (AD). The ability to automatically quantify the volume and thickness of the ERC and PRC is desirable because these localized measures can potentially serve as better imaging biomarkers for AD and other neurodegenerative diseases. However, large anatomical variation in the PRC makes it a challenging area for analysis. In order to address this problem, we propose an automatic segmentation, clustering, and thickness measurement approach that explicitly accounts for anatomical variation. The approach is targeted to highly anisotropic (0.4×0.4×2.0mm3) T2-weighted MRI scans that are preferred by many authors for detailed imaging of the MTL, but which pose challenges for segmentation and shape analysis. After automatically labeling MTL substructures using multi-atlas segmentation, our method clusters subjects into groups based on the shape of the PRC, constructs unbiased population templates for each group, and uses the smooth surface representations obtained during template construction to extract regional thickness measurements in the space of each subject. The proposed thickness measures are evaluated in the context of discrimination between patients with Mild Cognitive Impairment (MCI) and normal controls (NC). PMID:25320785

The cortical structure of consolidated memory: a hypothesis on the role of the cingulate-entorhinal cortical connection.

PubMed

Insel, Nathan; Takehara-Nishiuchi, Kaori

2013-11-01

Daily experiences are represented by networks of neurons distributed across the neocortex, bound together for rapid storage and later retrieval by the hippocampus. While the hippocampus is necessary for retrieving recent episode-based memory associations, over time, consolidation processes take place that enable many of these associations to be expressed independent of the hippocampus. It is generally thought that mechanisms of consolidation involve synaptic weight changes between cortical regions; or, in other words, the formation of "horizontal" cortico-cortical connections. Here, we review anatomical, behavioral, and physiological data which suggest that the connections in and between the entorhinal and cingulate cortices may be uniquely important for the long-term storage of memories that initially depend on the hippocampus. We propose that current theories of consolidation that divide memory into dual systems of hippocampus and neocortex might be improved by introducing a third, middle layer of entorhinal and cingulate allocortex, the synaptic weights within which are necessary and potentially sufficient for maintaining initially hippocampus-dependent associations over long time periods. This hypothesis makes a number of still untested predictions, and future experiments designed to address these will help to fill gaps in the current understanding of the cortical structure of consolidated memory. Copyright © 2013 Elsevier Inc. All rights reserved.

Grid-cell representations in mental simulation

PubMed Central

Bellmund, Jacob LS; Deuker, Lorena; Navarro Schröder, Tobias; Doeller, Christian F

2016-01-01

Anticipating the future is a key motif of the brain, possibly supported by mental simulation of upcoming events. Rodent single-cell recordings suggest the ability of spatially tuned cells to represent subsequent locations. Grid-like representations have been observed in the human entorhinal cortex during virtual and imagined navigation. However, hitherto it remains unknown if grid-like representations contribute to mental simulation in the absence of imagined movement. Participants imagined directions between building locations in a large-scale virtual-reality city while undergoing fMRI without re-exposure to the environment. Using multi-voxel pattern analysis, we provide evidence for representations of absolute imagined direction at a resolution of 30° in the parahippocampal gyrus, consistent with the head-direction system. Furthermore, we capitalize on the six-fold rotational symmetry of grid-cell firing to demonstrate a 60° periodic pattern-similarity structure in the entorhinal cortex. Our findings imply a role of the entorhinal grid-system in mental simulation and future thinking beyond spatial navigation. DOI: http://dx.doi.org/10.7554/eLife.17089.001 PMID:27572056

Dietary intake of unsaturated fatty acids modulates physiological properties of entorhinal cortex neurons in mice.

PubMed

Arsenault, Dany; Julien, Carl; Chen, Chuck T; Bazinet, Richard P; Calon, Frédéric

2012-07-01

Dietary lipids modify brain fatty acid profile, but evidence of their direct effect on neuronal function is sparse. The enthorinal cortex (EC) neurons connecting to the hippocampus play a critical role in learning and memory. Here, we have exposed mice to diets based on canola:soybean oils (40 : 10, g/kg) or safflower : corn oils (25 : 25, g/kg) to investigate the relationship between the lipid profile of brain fatty acids and the intrinsic properties of EC neurons. Consumption of canola : soybean oil-enriched diet led to the increase of the monounsaturated fatty acid oleic acid and to a decrease of arachidonic acid in ethanolamine glycerophospholipids of the white matter. We also found an important rise in docosahexaenoic acid (DHA) within ethanolamine glycerophospholipids and phosphatidylserine of gray matter. The canola:soybean oil treatment led to a shorter duration of action potential (-21%), a reduction in the duration of postsynaptic response (-21%) and increased firing activity (+43%). Data from additional experiments with animals fed DHA alone or DHA with canola oil suggested that dietary monounsaturated fatty acid may have contributed to these effects on EC neuron physiology. Since neuronal function within the enthorhinal-hippocampal loop is critical to learning and memory processes, the present data may provide a functional basis for the beneficial cognitive effects of canola oil-based diets. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

Differences in Visual-Spatial Input May Underlie Different Compression Properties of Firing Fields for Grid Cell Modules in Medial Entorhinal Cortex

DTIC Science & Technology

2015-11-19

cortex. These features can be described through the plane equation (nx, ny, nz )(Xi, Yi, Zi) T − d = 0 with the normal vector (nx, ny, nz ) the point...operator. Using Eq 2 and Eq 3 we find the following expression for the distance Di ¼ d nx sin yi cosi þ ny sini þ nz cos yi cosi : ð5Þ Plugging in

Aspiring and Aspiration Shaming: Primary Schooling, English, and Enduring Inequalities in Liberalizing Kerala (India)

ERIC Educational Resources Information Center

Mathew, Leya

2018-01-01

This paper analyzes narratives about the radical socio-economic changes accompanying liberalization in India to consider how English-medium schooling is becoming an aspirational resource for non-elite parents. I suggest that aspiring is a practice of ethics that marginalized mothers mobilize to negotiate memories of deprivation and yearnings for…

Thin-needle aspiration biopsy of the prostate.

PubMed

Koss, L G; Woyke, S; Schreiber, K; Kohlberg, W; Freed, S Z

1984-05-01

The authors summarize the current status of thin-needle aspiration biopsy of the prostate and evaluate the accomplishments and limitations of this method of diagnosis. Historical developments, indications, technique, contraindications, complications, cytology of aspirates, diagnostic efficacy of aspirates, and grading of prostatic carcinomas are discussed.

Efficacy of aspiration in amebic liver abscess.

PubMed

Ghosh, Jayant Kumar; Goyal, Sundeep Kumar; Behera, Manas Kumar; Tripathi, Manish Kumar; Dixit, Vinod Kumar; Jain, Ashok Kumar; Shukla, Ramchandra

2015-01-01

Amebic liver abscess (ALA) is a common and serious problem in our country. There are only a few controlled trials on the efficacy and advantages of combination therapy with percutaneous needle aspiration and pharmacotherapy, over pharmacotherapy alone for amebic liver abscess. This study was conducted to compare the efficacy of two different treatment modalities i.e. drug treatment alone vs. drug treatment and aspiration of abscess cavity in patients with small (up to 5 cm) and large (5 cm to 10 cm) size ALA. This is one of the largest single center, prospective, randomized studies comparing the efficacy of aspiration in ALA. (i) Mean body temperature, liver tenderness, total leukocyte count (TLC), serum alanine aminotransferase (ALT) and liver span were significantly decreased in the aspiration group on days 8 and 15 as compared to non-aspiration group especially in large abscess (5 cm to 10 cm). (ii) Abscess cavity maximum diameter decreased significantly in aspiration group on days 8 and 15, and 1 month & 3 months in large abscess (5cm to 10 cm). (i) Needle aspiration along with metronidazole hastens clinical improvement especially in large (5 cm up to 10 cm) cavities in patients with ALA. (ii) Aspiration is safe and no major complications occurred. (iii) Hence, combination therapy should be the first choice especially in large ALA (5 cm to 10 cm).

A new posterior iliac puncture/aspiration needle.

PubMed

Islam, Anwarul

2016-03-25

The needles that are currently used for obtaining bone marrow aspirate samples from the posterior ilium are typically those of 1930s vintage (eg, Klima, Salah or similar needles), which were specifically designed for sternal aspiration. These needles are not designed to obtain bone marrow aspirate samples from the posterior ilium and as a result they are unsatisfactory particularly if the patient is large or obese. A new posterior iliac puncture/aspiration needle has therefore been designed, which is particularly suited for bone marrow aspiration from the posterior ilium. The needle was tested on five cadavers and on five patients. The design and construction of the needle was found to be satisfactory and a marked improvement over the conventional sternal puncture needles particularly when large or obese patients were concerned. The new posterior iliac bone marrow aspiration needle has advantages that overcome the limitations of using a conventional sternal puncture needle to obtain marrow aspirates from the posterior ilium. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Neglected foreign body aspiration mimicking bronchial carcinoma.

PubMed

Afghani, Reza; Khandashpour Ghomi, Mahmoud; Khandoozi, Seyed Reza; Yari, Behrouz

2016-07-01

Foreign body aspiration can occur in any age group, but it is more commonly seen in children. In adults, there is usually a predisposing condition that poses a risk of aspiration. If aspiration occurs, prompt diagnosis and extraction of the foreign body is needed to prevent early and late complications. We report a rare case of neglected foreign body aspiration in a 45-year-old schizophrenic opium addicted patient, which resulted in an occlusive lesion in the bronchus, mimicking bronchial carcinoma. © The Author(s) 2016.

Spatially correlated heterogeneous aspirations to enhance network reciprocity

NASA Astrophysics Data System (ADS)

Tanimoto, Jun; Nakata, Makoto; Hagishima, Aya; Ikegaya, Naoki

2012-02-01

Perc & Wang demonstrated that aspiring to be the fittest under conditions of pairwise strategy updating enhances network reciprocity in structured populations playing 2×2 Prisoner's Dilemma games (Z. Wang, M. Perc, Aspiring to the fittest and promoted of cooperation in the Prisoner's Dilemma game, Physical Review E 82 (2010) 021115; M. Perc, Z. Wang, Heterogeneous aspiration promotes cooperation in the Prisoner's Dilemma game, PLOS one 5 (12) (2010) e15117). Through numerical simulations, this paper shows that network reciprocity is even greater if heterogeneous aspirations are imposed. We also suggest why heterogeneous aspiration fosters network reciprocity. It distributes strategy updating speed among agents in a manner that fortifies the initially allocated cooperators' clusters against invasion. This finding prompted us to further enhance the usual heterogeneous aspiration cases for heterogeneous network topologies. We find that a negative correlation between degree and aspiration level does extend cooperation among heterogeneously structured agents.

[Surgical management of refractory dysphagia and aspiration].

PubMed

Wang, Jian; Li, Wuyi; Liu, Jianhan; Xu, Chunxiao; Yang, Dahai; Huo, Hong; Tian, Xu; Zhang, Zhuhua; Chen, Yu

2015-02-01

To explore the methods and results of surgical management for refractory dysphagia and aspiration. The clinical data of 24 refractory dysphagia and aspiration patients who accepted surgical management were retrospectively analysed. Twenty-four refractory dysphagia and aspiration patients accepted 26 operations between 2001 and 2014. Of the 26 operations, 17 were cricopharyngeal myectomy (CPM), 6 were scarectomy, 3 were laryngeal-tracheal separation. No severe complications occurred. Assessments of dysphagia were completed in 18 operations before and after operation. Aspiration scores of videofluoroscopic swallowing study (VFSS) were 4.50 [4.00;7.00] vs 2.00 [1.00; 3.25], P = 0.000; swallow dysfunction scroes of VFSS were 5.00 [4.00; 12.00] vs 1.00 [1.50; 10.00], P = 0.001; aspiration scores of fibroptic endoscopic evaluation of swallowing (FEES) were 4.00 [5.00; 7.00] vs 2.00 [1.75; 3.00], P = 0.000. But the surgical results for post radiotherapy dysphagia were not successful (n = 5): aspiration scores of VFSS were 7.00 [6.50; 8.00] vs 6.00 [2.00; 7.50], P = 0.109;swallow dysfunction scroes of VFSS were 12.00 [10.50; 12.00] vs 12.00 [7.50; 12.00], P = 0.180;aspiration scores of FEES were 7.00 [6.50; 8.00] vs 6.00 [2.00; 7.50], P = 0.109. Surgical management was effective for refractory dysphagia and aspiration, but the surgical indication selection should be strict.

Suprapubic Bladder Aspiration in Neonates

PubMed Central

Akierman, Albert R.

1987-01-01

Suprapubic bladder aspiration in neonates is a simple, safe, and useful technique for collection of sterile urine. The procedure can be performed in the hospital or office. Neither sedation nor local anesthetic is required. Suprapubic bladder aspiration of urine is the preferred method of collecting urine for culture in septic neonates. The technique is also indicated to verify urinary tract infection in neonates. Suprapubic bladder aspiration is contraindicated in the presence of abdominal distension or an empty bladder. Carefully and properly performed, the risk of complications should be negligible, and the success rate in obtaining urine is 90%. ImagesFigure 1Figure 2 PMID:21263980

Carbachol-induced network oscillations in an in vitro limbic system brain slice.

PubMed

Lévesque, Maxime; Cataldi, Mauro; Chen, Li-Yuan; Hamidi, Shabnam; Avoli, Massimo

2017-04-21

We employed simultaneous field potential recordings from CA3, subiculum and entorhinal cortex in an in vitro brain slice preparation to understand the involvement of these limbic areas in the generation of the field potential oscillations that are induced by bath application of the muscarinic receptor agonist carbachol. Regularly spaced oscillations that mainly presented at theta frequency range (5-12Hz) occurred synchronously in all three structures in the presence of carbachol. These oscillations, which disappeared when slices were perfused with pirenzepine or with glutamatergic receptor antagonists, were categorized as short (<4s) and long (>4s) with short events oscillating at higher frequencies than long events. Field oscillations were highly synchronized between regions and latency analysis revealed that they often initiated in the entorhinal cortex later than in the other two structures. Blocking GABA A receptors modified the activity patterns of both short and long oscillations and decreased their coherence in the theta frequency range. Finally, blocking KCC2 activity disclosed a pattern of recurrent short oscillations. Our results suggest that in the presence of carbachol both subiculum and CA3 most often drive theta generators in the entorhinal cortex and that these oscillations are influenced but not abolished by altering GABA A receptor signaling. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

Educational Aspirations Trajectories in England

ERIC Educational Resources Information Center

McCulloch, Andrew

2017-01-01

This study used latent class analysis to examine the trajectories followed by young people's educational aspirations in England over the age range from 13 to 16 years and their relationship to educational achievement. The results suggested that young people's aspirations followed six trajectories. Four trajectories showed overall patterns of…

[Spatial Cognition and Episodic Memory Formation in the Limbic Cortex].

PubMed

Kobayashi, Yasushi

2017-04-01

The limbic lobe defined by Broca is a cortical region with highly diverse structure and functions, and comprises the paleo-, archi-, and neocortices as well as their transitional zones. In the limbic lobe, Brodmann designated areas 27, 28, 34, 35, and 36 adjacent to the hippocampus, and areas 23, 24, 25, 26, 29, 30, 31, 32, and 33 around the corpus callosum. In the current literature, areas 27 and 28 correspond to the presubiculum and entorhinal cortex, respectively. Area 34 represents the cortico-medial part of the amygdaloid complex. Areas 35 and 36 roughly cover the perirhinal and parahippocampal cortices. Areas 24, 25, 32, and 33 belong to the anterior cingulate gyrus, while areas 23, 26, 29, 30, and 31 to the posterior cingulate gyrus. Areas 25, 32, and the anteroinferior portion of area 24 are deeply involved in emotional responses, particularly in their autonomic functions, through reciprocal connections with the amygdaloid complex, anterior thalamus and projections to the brainstem and spinal visceral centers. Areas 29 and 30 have dense reciprocal connections with areas 23 and 31, the dorsolateral prefrontal areas, and the regions related to the hippocampus. They play pivotal roles in mediating spatial cognition, working memory processing, and episodic memory formation.

Aspiration and Biopsy: Bone Marrow

MedlinePlus

... Print What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy liquid part of the bone where blood cells are ... you might also feel the pressure of the biopsy needle pushing in. Some ... sharp cramp as the liquid bone marrow is withdrawn for the aspiration or ...

The medial frontal cortex contributes to but does not organize rat exploratory behavior.

PubMed

Blankenship, Philip A; Stuebing, Sarah L; Winter, Shawn S; Cheatwood, Joseph L; Benson, James D; Whishaw, Ian Q; Wallace, Douglas G

2016-11-12

Animals use multiple strategies to maintain spatial orientation. Dead reckoning is a form of spatial navigation that depends on self-movement cue processing. During dead reckoning, the generation of self-movement cues from a starting position to an animal's current position allow for the estimation of direction and distance to the position movement originated. A network of brain structures has been implicated in dead reckoning. Recent work has provided evidence that the medial frontal cortex may contribute to dead reckoning in this network of brain structures. The current study investigated the organization of rat exploratory behavior subsequent to medial frontal cortex aspiration lesions under light and dark conditions. Disruptions in exploratory behavior associated with medial frontal lesions were consistent with impaired motor coordination, response inhibition, or egocentric reference frame. These processes are necessary for spatial orientation; however, they are not sufficient for self-movement cue processing. Therefore it is possible that the medial frontal cortex provides processing resources that support dead reckoning in other brain structures but does not of itself compute the kinematic details of dead reckoning. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Parvalbumin and calbindin immunoreactivity in the cerebral cortex of the hedgehog (Erinaceus europaeus).

PubMed Central

Ferrer, I; Zujar, M J; Admella, C; Alcantara, S

1992-01-01

To investigate the morphology and distribution of nonpyramidal neurons in the brain of insectivores, parvalbumin and calbindin 28 kDa immunoreactivity was examined in the cerebral cortex of the hedgehog (Erinaceus europaeus). Parvalbumin-immunoreactive cells were found in all layers of the isocortex, but in contrast to other mammals, a laminar organisation or specific regional distribution was not seen. Characteristic parvalbumin-immunoreactive neurons were multipolar cells with large ascending and descending dendrites extending throughout several layers. Calbindin-immunoreactive neurons were similar to those found in other species, although appearing in smaller numbers than in the cerebral cortex of more advanced mammals. The morphology and distribution of parvalbumin- and calbindin-immunoreactive cells in the piriform and entorhinal cortices were similar in hedgehogs and rodents. Parvalbumin-immunoreactive cells in the hippocampal complex were pyramidal-like and bitufted neurons, which were mainly found in the stratum oriens and stratum pyramidale of the hippocampus, and in the stratum moleculare and hilus of the fascia dentata. Heavily stained cells were found in the deep part of the stratum granulare. Intense calbindin immunoreactivity occurred mainly in the granule cell and molecular layers of the dentate gyrus and in the mossy fibre layer. The most outstanding feature in the hippocampal complex of the hedgehog was the extension of calbindin immunoreactivity to CA1 field of the hippocampus, suggesting, in agreement with other reports, that mossy fibres can establish synaptic contacts throughout the pyramidal cell layer. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:1452472

Diminution of context association memory structure in subjects with subjective cognitive decline.

PubMed

Fan, Ling-Yun; Lai, Ya-Mei; Chen, Ta-Fu; Hsu, Yung-Chin; Chen, Pin-Yu; Huang, Kuo-Zhou; Cheng, Ting-Wen; Tseng, Wen-Yi Isaac; Hua, Mau-Sun; Chen, Ya-Fang; Chiu, Ming-Jang

2018-06-01

Alzheimer's disease (AD) progresses insidiously from the preclinical stage to dementia. While people with subjective cognitive decline (SCD) have normal cognitive performance, some may be in the preclinical stage of AD. Neurofibrillary tangles appear first in the transentorhinal cortex, followed by the entorhinal cortex in the clinically silent stage of AD. We expected the earliest changes in subjects with SCD to occur in medial temporal subfields other than the hippocampal proper. These selective structural changes would affect specific memory subcomponents. We used the Family Picture subtest of the Wechsler Memory Scale-III, which was modified to separately compute character, activity, and location subscores for episodic memory subcomponents. We recruited 43 subjects with SCD, 44 subjects with amnesic mild cognitive impairment, and 34 normal controls. MRI was used to assess cortical thickness, subcortical gray matter volume, and fractional anisotropy. The results demonstrated that SCD subjects showed significant cortical atrophy in their bilateral parahippocampus and perirhinal and the left entorhinal cortices but not in their hippocampal regions. SCD subjects also exhibited significantly decreased mean fractional anisotropy in their bilateral uncinate fasciculi. The diminution of cortical thickness over the mesial temporal subfields corresponded to brain areas with early tangle deposition, and early degradation of the uncinate fasciculus was in accordance with the retrogenesis hypothesis. The parahippocampus and perirhinal cortex contribute mainly to context association memory while the entorhinal cortex, along with the uncinate fasciculus, contributes to content-related contextual memory. We proposed that context association and related memory structures are vulnerable in the SCD stage. © 2018 Wiley Periodicals, Inc.

Differential effects of LifeAct-GFP and actin-GFP on cell mechanics assessed using micropipette aspiration.

PubMed

Sliogeryte, Kristina; Thorpe, Stephen D; Wang, Zhao; Thompson, Clare L; Gavara, Nuria; Knight, Martin M

2016-01-25

The actin cytoskeleton forms a dynamic structure involved in many fundamental cellular processes including the control of cell morphology, migration and biomechanics. Recently LifeAct-GFP (green fluorescent protein) has been proposed for visualising actin structure and dynamics in live cells as an alternative to actin-GFP which has been shown to affect cell mechanics. Here we compare the two approaches in terms of their effect on cellular mechanical behaviour. Human mesenchymal stem cells (hMSCs) were analysed using micropipette aspiration and the effective cellular equilibrium and instantaneous moduli calculated using the standard linear solid model. We show that LifeAct-GFP provides clearer visualisation of F-actin organisation and dynamics. Furthermore, LifeAct-GFP does not alter effective cellular mechanical properties whereas actin-GFP expression causes an increase in the cell modulus. Interestingly, LifeAct-GFP expression did produce a small (~10%) increase in the percentage of cells exhibiting aspiration-induced membrane bleb formation, whilst actin-GFP expression reduced blebbing. Further studies examined the influence of LifeAct-GFP in other cell types, namely chondrogenically differentiated hMSCs and murine chondrocytes. LifeAct-GFP also had no effect on the moduli of these non-blebbing cells for which mechanical properties are largely dependent on the actin cortex. In conclusion we show that LifeAct-GFP enables clearer visualisation of actin organisation and dynamics without disruption of the biomechanical properties of either the whole cell or the actin cortex. Thus the study provides new evidence supporting the use of LifeAct-GFP rather than actin-GFP for live cell microscopy and the study of cellular mechanobiology. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

GEAR UP Aspirations Project Evaluation

ERIC Educational Resources Information Center

Trimble, Brad A.

2013-01-01

The purpose of this study was to conduct a formative evaluation of the first two years of the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) Aspirations Project (Aspirations) using a Context, Input, Process, and Product (CIPP) model so as to gain an in-depth understanding of the project during the middle school…

Aspiration and sclerotherapy versus hydrocelectomy for treatment of hydroceles.

PubMed

Beiko, Darren T; Kim, Dennis; Morales, Alvaro

2003-04-01

To compare aspiration and sclerotherapy using sodium tetradecylsulfate (STDS) with open hydrocelectomy in the treatment of hydroceles with regard to safety, efficacy, and cost-effectiveness. Patients with symptomatic hydroceles were prospectively enrolled in an aspiration and sclerotherapy protocol between October 1998 and June 2000. Patients in this group underwent percutaneous aspiration followed by sclerotherapy with an STDS-based solution. This group was compared with a group of patients chosen consecutively who underwent hydrocelectomy between December 1996 and August 1999. Primary outcome measures included patient satisfaction and procedural success. Secondary outcome measures included complications and comparative costs. A total of 27 patients with 28 hydroceles were enrolled in the aspiration and sclerotherapy protocol and compared with 24 patients with 25 hydroceles in the hydrocelectomy group. Mean follow-up for the aspiration and sclerotherapy group and hydrocelectomy group was 8.9 and 16.4 months, respectively. Patient satisfaction was 75% for aspiration and sclerotherapy and 88% for hydrocelectomy. The overall success rate for aspiration and sclerotherapy was 76% compared with 84% for hydrocelectomy. The complication rate was only 8% in the aspiration and sclerotherapy group, but 40% in the hydrocelectomy group. Comparative costs per procedure demonstrated that hydrocelectomy was almost ninefold more expensive than aspiration and sclerotherapy. In the treatment of hydroceles, aspiration and sclerotherapy with STDS represents a minimally invasive approach that is simple, inexpensive, and safe but less effective than hydrocelectomy. Aspiration and sclerotherapy is a viable first-line therapeutic option in the management of hydroceles.

A Vacuum-Aspirator for Counting Termites

Treesearch

Susan C. Jones; Joe K. Mauldin

1983-01-01

An aspirator-system powered by a vacuum cleaner is described for manually counting termites. It is significantly faster and termite survival is at least as high as when using a mouth-aspirator for counting large numbers of termites.

Thrombus aspiration catheter is a Dottering balloon.

PubMed

Sheshagiri Rao, D; Barik, Ramachandra; Prasad, Akula Siva

2016-01-01

Coronary angiogram in a young man with history of STEMI with delayed presentation revealed subtotal occlusion of left anterior descending artery (LAD) with large thrombotic filling defect distal to the critical lesion. PCI was preferred without delay because of ongoing chest pain. Several runs of thrombus aspiration failed to detect any visible thrombus. However, the immediate angiogram after thrombus aspiration showed complete distal embolization of the thrombus which could have been achieved by Dottering or balloon dilatation. In contrary to the general perception, does thrombus aspiration push more thrombus than it can aspirate? Copyright © 2016 Cardiological Society of India. Published by Elsevier B.V. All rights reserved.

Aspiration and sclerotherapy: a nonsurgical treatment option for hydroceles.

PubMed

Francis, John J; Levine, Laurence A

2013-05-01

We demonstrated that hydrocele aspiration and sclerotherapy with doxycycline is an effective and safe nonsurgical treatment option for hydrocele correction. The medical records of patients who underwent hydrocele aspiration and sclerotherapy were analyzed in a retrospective cohort study for success rates as well as improvement in scrotal size and discomfort after a single hydrocele aspiration and sclerotherapy treatment. Patients who reported decreased scrotal size, improved physical symptoms and satisfaction with the procedure were considered as having success with hydrocele aspiration and sclerotherapy. A total of 29 patients (mean age 52.8 years) presenting with 32 nonseptated hydroceles underwent hydrocele aspiration and sclerotherapy with doxycycline between 2005 and 2012. Of the hydroceles 27 (84%) were successfully treated with a single aspiration and sclerotherapy procedure. Overall mean followup was 20.8 months. Three patients reported moderate pain which resolved in 2 to 3 days. Of those patients in whom hydrocele aspiration and sclerotherapy failed, 1 had hydrocele successfully resolved with a second aspiration and sclerotherapy treatment, 3 did not have success with a second procedure and underwent hydrocelectomy, and 1 wanted immediate surgical correction. Hydrocele aspiration and sclerotherapy was successful in correcting 84% of simple nonseptated hydroceles with a single treatment. This result is an increase from previously reported success rates involving a single hydrocele aspiration and sclerotherapy procedure with tetracycline (75%). The success rate of a single hydrocele aspiration and sclerotherapy procedure is similar to the reported success rates involving hydrocelectomy while avoiding the hospital expense and many other complications. We conclude that the hydrocele aspiration and sclerotherapy procedure is a reasonable, nonsurgical and underused treatment option for nonseptated simple hydroceles. Copyright © 2013 American Urological

Competitive (AP7) and non-competitive (MK-801) NMDA receptor antagonists differentially alter glucose utilization in rat cortex

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

Clow, D.W.; Lee, S.J.; Hammer, R.P. Jr.

1991-04-01

The effects of D,L-2-amino-7-phosphonoheptanoic acid (AP7), a competitive N-methyl-D-aspartate (NMDA) receptor antagonist, and MK-801, a non-competitive NMDA receptor antagonist, on regional brain metabolism were studied in unanesthetized, freely moving rats by using the quantitative {sup 14}C2-deoxyglucose autoradiographic procedure. AP7 (338 or 901 mg/kg) produced a dose-dependent decrease of metabolic activity throughout most of the regions studied including sensory, motor, and limbic cortices. In contrast, MK-801 (0.1 or 1.0 mg/kg) resulted in a dose-dependent decrease of metabolic activity in sensory cortices, and an increase in limbic regions such as the hippocampal stratum lacunosum moleculare and entorhinal cortex. MK-801 also produced amore » biphasic response in agranular motor cortex, whereby the low dose increased while the high dose decreased labeling. In addition, MK-801 produced heterogeneous effects on regional cerebral metabolism in sensory cortices. Metabolic activity decreased in layer IV relative to layer Va following MK-801 treatment in primary somatosensory (SI) and visual (VI) cortices, suggesting a shift in activity from afferent fibers innervating layer IV to those innervating layer Va. MK-801 administration also decreased metabolic activity in granular SI relative to dysgranular SI, and in VI relative to secondary visual cortex (VII), thus providing a relative sparing of activity in dysgranular SI and VII. Thus, the non-competitive NMDA receptor antagonist suppressed activity from extrinsic neocortical sources, enhancing relative intracortical activity and stimulating limbic regions, while the competitive NMDA antagonist depressed metabolic activity in all cortical regions.« less

Foreign body aspiration in dentistry: a review.

PubMed

Cameron, S M; Whitlock, W L; Tabor, M S

1996-08-01

This article reviews the dangers of aspirating foreign bodies of dental origin. Two illustrative cases are presented, including an unusual case involving aspiration of an elastomeric impression material. The authors describe the techniques used to identify the foreign body. A radiodensimetric study of four impression materials demonstrates the difficulty of identifying most impression materials. The authors also present some strategies for reducing the risk of aspiration during dental procedures.

Pre-hospital aspiration is associated with increased pulmonary complications.

PubMed

Fawcett, Vanessa J; Warner, Keir J; Cuschieri, Joseph; Copass, Michael; Grabinsky, Andreas; Kwok, Heemun; Rea, Thomas; Evans, Heather L

2015-04-01

Rates of ventilator-associated pneumonia (VAP) are highest among patients intubated on an emergency basis following trauma. We reported previously a retrospective analysis demonstrating an association between subjective aspiration and VAP after pre-hospital intubation. We hypothesize that by directing paramedics to note features of aspiration at intubation, we will confirm prospectively the association between pre-hospital aspiration and subsequent pneumonia in trauma patients. Paramedics collected data regarding aspiration at the time of intubation. All intubated patients admitted to a level 1 trauma center intensive care unit (ICU) were included. Data comprised a clinical impression of pre-hospital aspiration, as well as the presence and timing of blood and emesis in the airway. Injury severity, co-morbidities, and outcomes were collected from the trauma registry. Healthcare-associated pneumonia (HAP) was identified by medical record review of both bronchoalveolar lavage culture results and discharge diagnosis. Descriptive statistics and univariate analysis of outcomes by aspiration status, as well as covariable adjustment using propensity scores, were performed. Of the 228 patients, 89 (39%) were determined by paramedics to have aspirated. The majority of those who aspirated (84 [94%]) did so prior to intubation. Patients who aspirated had higher Injury Severity Scores than those who did not aspirate (25.0 ± 1.7 vs. 21.9 ± 1.5 points; p=0.04) and lower preintubation Glasgow Coma Scale scores (8.2 ± 0.50 vs. 9.6 ± 0.40; p=0.02). Of the 89 patients who aspirated around the time of intubation, 14 (16%) developed HAP vs. five (3.6%) of those who did not aspirate (p<0.01). We observed non-significant increases in mortality rate, ICU length of stay (LOS) and duration of mechanical ventilation after aspiration (deaths: 21 [23.6%] vs. 23 [16.6%]; p=0.19; ICU LOS: 5.3 ± 0.9 vs. 4.1 ± 0.5 days; p=0.13; duration of mechanical ventilation: 5.3 ± 1.2 vs. 3.2 ± 0

Theta-burst microstimulation in the human entorhinal area improves memory specificity.

PubMed

Titiz, Ali S; Hill, Michael R H; Mankin, Emily A; M Aghajan, Zahra; Eliashiv, Dawn; Tchemodanov, Natalia; Maoz, Uri; Stern, John; Tran, Michelle E; Schuette, Peter; Behnke, Eric; Suthana, Nanthia A; Fried, Itzhak

2017-10-24

The hippocampus is critical for episodic memory, and synaptic changes induced by long-term potentiation (LTP) are thought to underlie memory formation. In rodents, hippocampal LTP may be induced through electrical stimulation of the perforant path. To test whether similar techniques could improve episodic memory in humans, we implemented a microstimulation technique that allowed delivery of low-current electrical stimulation via 100 μm -diameter microelectrodes. As thirteen neurosurgical patients performed a person recognition task, microstimulation was applied in a theta-burst pattern, shown to optimally induce LTP. Microstimulation in the right entorhinal area during learning significantly improved subsequent memory specificity for novel portraits; participants were able both to recognize previously-viewed photos and reject similar lures. These results suggest that microstimulation with physiologic level currents-a radical departure from commonly used deep brain stimulation protocols-is sufficient to modulate human behavior and provides an avenue for refined interrogation of the circuits involved in human memory.

Liposuction: more curettage than aspiration.

PubMed

Mottura, A A

1991-01-01

After infiltration with epinephrine solution in each adipose area, an 8- or 10-mm cannula, without the suction tube connected, was introduced. With a curettage maneuver and by directing the cannula upward, the fat began to come out spontaneously. After obtaining a considerable amount of fat, the suction tube was connected and the remaining fat tissue aspirated at low suction power (250 mm Hg). With this curettage maneuver adiposity of the abdomen, knees, and trochanteric areas can be reduced. However, in the back, buttocks, or thighs, where adiposity is more fibrous, aspiration is needed from the start in almost every case, but always at low-power suction. This procedure is indicated in particular for the face and neck and for secondary liposuction. The fact that fat comes out easily through the cannula (without suction) demonstrates that the curettage maneuver is more important than the aspiration. Only with curettage can a considerable amount of fat be removed. No fat is removed when aspiration of 1 atm without a curettage maneuver is used. Suction only helps to remove fat already mobilized and free in the cannula. Our experience includes 34 patients.

Choosing VET: Aspirations, Intentions and Choice

ERIC Educational Resources Information Center

Hargreaves, Jo; Osborne, Kristen

2017-01-01

This summary brings together the findings from two research projects: "Choosing VET: Investigating the VET Aspirations of School Students" and "In Their Words: Student Choice in Training Markets--Victorian Examples." The research investigated school students' post-school aspirations for vocational education and training (VET),…

Aspirations, Expectations and Delinquency: The Moderating Effect of Impulse Control.

PubMed

Mahler, Alissa; Simmons, Cortney; Frick, Paul J; Steinberg, Laurence; Cauffman, Elizabeth

2017-07-01

Although prior research finds a robust link between delinquent behavior and expectations, or an adolescent's perceived likelihood of obtaining one's future goals, fewer studies have evaluated aspirations, or the perceived importance of achieving one's goals. In addition, few studies consider how individual traits such as impulsivity affect the degree to which expectations and aspirations motivate or deter delinquent behavior. We contribute to this body of research by evaluating the independent effects of expectations and aspirations, and the aspiration-expectation gap (i.e., strain) on delinquent behavior during the year following an adolescent's first arrest using a large (N = 1117), racially/ethnically diverse sample of male adolescents (46.55% Latino, 35.81% Black, 14.95% White, and 2.69% Other race). In addition, we considered how impulse control interacts with expectations, aspirations, and strain to motivate behavior. Our results indicated that both aspirations, expectations and strain uniquely influence criminal behavior. Importantly, aspirations interacted with impulse control, such that aspirations affected delinquency only among youth with higher impulse control. Our findings suggest that aspirations may only influence behavior if youth also have the psychosocial capabilities to consider their future aspirations when behaving in the present.

Aspirator increases relief valve poppet stroke

NASA Technical Reports Server (NTRS)

Biddle, M. E.

1967-01-01

Addition of an aspirator to a relief valve increases the valve poppet stroke under dynamic flow conditions. The aspirator allows poppet inlet dynamic forces to overcome relief valve spring force. It reduces the fluid pressure in the skirt cavity by providing a low pressure sense probe.

[Aspirative pneumonia associated to swallowing dysfunction: case report].

PubMed

Toufen Junior, Carlos; Camargo, Fernanda Pereira de; Carvalho, Carlos Roberto Ribeiro

2007-03-01

Critically ill patients represent a population with multiple risk factors for aspiration. Features such as decreased level of consciousness, mechanical ventilation, and comorbities as stroke, correlate with this increased threat in intensive care unit (ICU) patients. Recognition of deglutition dysfunction may identify patients at high risk of aspiration, and thereby help to avoid pulmonary complications such as recurrent pneumonia. The goal of our report is show a severe case of recurrent aspirative pneumonia after acute stroke and intubation, alerting to appropriate diagnosis and treatment of this condition. A male patient, 57 year old, was admitted to the hospital because of acute stroke. Ten days later, the patient began to have fever and severe shortness of breath. He was admitted to the ICU necessitating of intratracheal intubation. Four days after intubation he was extubated, however, he had a new aspirative pneumonia in ICU, newly treated. An evaluation of swallowing demonstrated a severe deglutition dysfunction with a high risk of aspiration. The patient was transferred, but aspirative pneumonia was diagnosed eight days after his ICU discharge and he was readmitted, stayed for a long time in ICU and presenting severe morbidity. ICU patients who are at risk for swallowing dysfunction and aspiration should be identified to prevent their associated morbidity and mortality.

Remote Possibilities: Rural Children's Educational Aspirations

ERIC Educational Resources Information Center

Howley, Caitlin W.

2006-01-01

To better understand the influence of rural context on youth's life chances, this study takes up the question of rural children's educational aspirations. The experience of rural life may, as some claim, limit students' educational aspirations. Yet there are indications that rural communities simultaneously generate important social benefits that…

Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

MedlinePlus

... News Physician Resources Professions Site Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid ... Needle Aspiration Biopsy of the Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? ...

Employment, Academic and Extracurricular Contributors to College Aspirations

ERIC Educational Resources Information Center

McGaha, Valerie; Fitzpatrick, Jacki

2010-01-01

Although there have been many studies on college entrance and aspirations, little attention has been paid to post-high school adults (who enter the workworld rather than college). it is possible that post-high school adults still have college aspirations, and it would be valuable to identify the factors that foster such aspirations. This study…

Elemental concentration analysis in brain structures from young, adult and old Wistar rats by total reflection X-ray fluorescence with synchrotron radiation

NASA Astrophysics Data System (ADS)

Serpa, R. F. B.; de Jesus, E. F. O.; Anjos, M. J.; do Carmo, M. G. T.; Moreira, S.; Rocha, M. S.; Martinez, A. M. B.; Lopes, R. T.

2006-11-01

The knowledge of the spatial distribution and the local concentration of trace elements in tissues are of great importance since trace elements are involved in a number of metabolic and physiological processes in the human body, and their deficiency and excess may lead to different metabolic disorders. In this way, the main goal of this work is to compare the elemental concentration in different brain structures, namely temporal cortex, entorhinal cortex, visual cortex and hippocampus, from Wistar female rats ( n = 15) with different ages: 2, 8 and 48 weeks. The measurements were performed at the Synchrotron Light Brazilian Laboratory, Campinas, São Paulo, Brazil. In the entorhinal cortex, the following elements decreased with age: Zn, S, Cl, K, Ca and Br. In the temporal cortex, Ca, Fe and Br levels increased with aging and on the other hand, P, S, Cl, K and Rb levels decreased with aging. In the visual cortex almost all the elements decreased with aging: Cl, Ca, Fe, Ni and Zn. In the hippocampus, in turn, most of the elements identified, increased with aging: Al, P, S, K, Fe, Cu, Zn and Rb. The increase of Fe with aging in the hippocampus is an important fact that will be studied, since it is involved in oxidative stress. It is believed that oxidative stress is the one of the main causes responsible for neuronal death in Parkinson's disease.

Theta Coordinated Error-Driven Learning in the Hippocampus

PubMed Central

Ketz, Nicholas; Morkonda, Srinimisha G.; O'Reilly, Randall C.

2013-01-01

The learning mechanism in the hippocampus has almost universally been assumed to be Hebbian in nature, where individual neurons in an engram join together with synaptic weight increases to support facilitated recall of memories later. However, it is also widely known that Hebbian learning mechanisms impose significant capacity constraints, and are generally less computationally powerful than learning mechanisms that take advantage of error signals. We show that the differential phase relationships of hippocampal subfields within the overall theta rhythm enable a powerful form of error-driven learning, which results in significantly greater capacity, as shown in computer simulations. In one phase of the theta cycle, the bidirectional connectivity between CA1 and entorhinal cortex can be trained in an error-driven fashion to learn to effectively encode the cortical inputs in a compact and sparse form over CA1. In a subsequent portion of the theta cycle, the system attempts to recall an existing memory, via the pathway from entorhinal cortex to CA3 and CA1. Finally the full theta cycle completes when a strong target encoding representation of the current input is imposed onto the CA1 via direct projections from entorhinal cortex. The difference between this target encoding and the attempted recall of the same representation on CA1 constitutes an error signal that can drive the learning of CA3 to CA1 synapses. This CA3 to CA1 pathway is critical for enabling full reinstatement of recalled hippocampal memories out in cortex. Taken together, these new learning dynamics enable a much more robust, high-capacity model of hippocampal learning than was available previously under the classical Hebbian model. PMID:23762019

Depletion of microglia and inhibition of exosome synthesis halt tau propagation

PubMed Central

Asai, Hirohide; Ikezu, Seiko; Tsunoda, Satoshi; Medalla, Maria; Luebke, Jennifer; Haydar, Tarik; Wolozin, Benjamin; Butovsky, Oleg; Kügler, Sebastian; Ikezu, Tsuneya

2015-01-01

Accumulation of pathological tau protein is a major hallmark of Alzheimer’s disease. Tau protein spreads from the entorhinal cortex to the hippocampal region early in the disease. Microglia, the primary phagocytes in the brain, are positively correlated with tau pathology, but their involvement in tau propagation is unknown. We developed an adeno-associated virus–based model exhibiting rapid tau propagation from the entorhinal cortex to the dentate gyrus in 4 weeks. We found that depleting microglia dramatically suppressed the propagation of tau and reduced excitability in the dentate gyrus in this mouse model. Moreover, we demonstrate that microglia spread tau via exosome secretion, and inhibiting exosome synthesis significantly reduced tau propagation in vitro and in vivo. These data suggest that microglia and exosomes contribute to the progression of tauopathy and that the exosome secretion pathway may be a therapeutic target. PMID:26436904

Clinical profile of children with kerosene aspiration.

PubMed

Venkatesh, C; Sriram, P; Adhisivam, B; Mahadevan, S

2011-07-01

Accidental aspiration of kerosene is a common problem among children in developing countries. This descriptive study involved the retrospective analysis of children admitted with kerosene aspiration in a tertiary care hospital in South India for a year. Kerosene aspiration contributed to 60.4% of poisoning cases. Boys aged less than three years and from a rural background formed a significant proportion. Tachypnoea, cough and crepitations were the predominant clinical findings. Male gender and malnutrition (weight for age <80%) were significantly associated with prolonged hospital stay.

Cortical thinning in type 2 diabetes mellitus and recovering effects of insulin therapy.

PubMed

Chen, Zhiye; Sun, Jie; Yang, Yang; Lou, Xin; Wang, Yulin; Wang, Yan; Ma, Lin

2015-02-01

The purpose of this study was to explore the brain structural changes in type 2 diabetes and the effect of insulin on the brain using a surface-based cortical thickness analysis. High-resolution three-dimensional T1-weighted fast spoiled gradient recalled echo MRI were obtained from 11 patients with type 2 diabetes before and after insulin therapy. The cortical thickness over the entire brain was calculated, and cross-sectional and longitudinal surface-based cortical thickness analyses were also performed. Regional cortical thinning was demonstrated in the middle temporal gyrus, posterior cingulate gyrus, precuneus, right lateral occipital gyrus and entorhinal cortex bilaterally for patients with type 2 diabetes mellitus compared with normal controls. Cortical thickening was seen in the middle temporal gyrus, entorhinal cortex and left inferior temporal gyrus bilaterally after patients underwent 1 year of insulin therapy. These findings suggest that insulin therapy may have recovering effects on the brain cortex in type 2 diabetes mellitus. The precise mechanism should be investigated further. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fatal aspiration of foreign bodies in infants and children.

PubMed

Bamber, Andrew R; Pryce, Jeremy; Ashworth, Michael; Sebire, Neil J

2014-02-01

To investigate the frequency, circumstances, demographics and autopsy findings of infants and children dying as a result of foreign body aspiration. Retrospective review of autopsy cases in children aged between seven days and 18 years, at one specialist centre over a 16-year period, in which death was the result of aspiration of a foreign body. Ten cases were identified out of a total autopsy population of 2165. Only one individual had an underlying diagnosis potentially contributing to aspiration. All but one case involved aspiration of food, with grapes being a feature of four cases. In cases with a prolonged survival interval, autopsy demonstrated bronchopneumonia and hypoxic-ischaemic encephalopathy. In the remaining cases autopsy findings were non-specific. Fatal aspiration of a foreign body is rare in this population. The cases involve normal children who aspirate food, particularly grapes. There are typically minimal, non-specific findings at autopsy.

Aspirations: The Moral of The Story

ERIC Educational Resources Information Center

Baker, William

2017-01-01

This article argues for the importance of studying the moral meanings that young people attach to their aspirations and plans for the future. Drawing on semi-structured interview data with 29 young people from a sixth-form college in a disadvantaged area of East London, I show that aspirations are closely connected to the formation of individual…

Aspiration pneumonia. Pathophysiological aspects, prevention and management. A review.

PubMed

Petroianni, A; Ceccarelli, D; Conti, V; Terzano, C

2006-12-01

Aspiration pneumonias occur more frequently than reported and, in many cases, the disease is not recognised. In hospitalised and institutionalised patients with predisposing diseases prompt diagnosis of this complication and correct preventive measures can drastically reduce the worsening of clinical conditions and the deaths due to aspiration pneumonia. Normal airway structure, effective defence mechanisms, and preventive measures are decisive in reducing aspiration episodes. An increased aspiration risk for food, fluids, medications, or secretions may lead to the development of pneumonia. Pneumonia is the most common respiratory complication in all stroke deaths and in mechanical ventilation patients. In addition, the increased incidence of aspiration pneumonia with aging may be a consequence of impairment of swallowing and the cough reflex. Dysphagia, compromised consciousness, invasive procedures, anaesthesia, insufficient oral care, sleep disorders, and vomiting are all risk factors. Aspiration pneumonia includes different characteristic syndromes based on the amount (massive, acute, chronic) and physical character of the aspirated material (acid, infected, lipoid), needing a different therapeutic approach. Chronic patients education and correct health care practices are the keys for preventing the events of aspiration. In patients at risk a clinical and instrumental assessment of dysphagia should be evaluated. Management includes the removal of etiologic factors (drugs, tubes, mobilisation, oral hygiene), supportive care, and in bacterial pneumonias a specific antibiotic therapy for community-acquired or nosocomial events.

Videofluoroscopic Predictors of Penetration-Aspiration in Parkinson's Disease Patients.

PubMed

Argolo, Natalie; Sampaio, Marília; Pinho, Patrícia; Melo, Ailton; Nóbrega, Ana Caline

2015-12-01

Parkinson's disease (PD) patients show a high prevalence of swallowing disorders and tracheal aspiration of food. The videofluoroscopic study of swallowing (VFSS) allows clinicians to visualize the visuoperceptual and temporal parameters associated with swallowing disorders in an attempt to predict aspiration risk. However, this subject remains understudied in PD populations. Our aim was to identify the predictors of penetration-aspiration in PD patients using the VFSS. Consecutive patients were evaluated using VFSS with different consistencies and volumes of food. A speech-language pathologist measured the type of intra-oral bolus organization, loss of bolus control, bolus location at the initiation of the pharyngeal swallow, the presence of multiple swallows, piecemeal deglutition, bolus residue in the pharyngeal recesses and temporal measures. Scores ≥3 on the penetration-aspiration scale (PAS) indicated the occurrence of penetration-aspiration. Using logistic marginal regression, we found that residue in the vallecula, residue in the upper esophageal sphincter and piecemeal deglutition were associated with penetration-aspiration (odds ratio (OR) = 4.09, 2.87 and 3.83; P = 0.0040, 0.0071 and 0.0009, respectively). Penetration/aspiration occurred only with fluids (both of thin and thick consistency), and no significant differences were observed between fluid types or food volumes. The mechanisms underlying dysphagia and penetration/aspiration in PD patients and indications for further studies are discussed.

Joint Aspiration (Arthrocentesis)

MedlinePlus

... arthritis, or JRA), systemic lupus erythematosus (SLE), and Lyme disease. Joint aspiration is diagnostic but it also can ... topic for: Parents Kids Teens Evaluate Your Child's Lyme Disease Risk Living With Lupus Bones, Muscles, and Joints ...

Antacid aspiration in rabbits: a comparison of Mylanta and Bicitra.

PubMed

Eyler, S W; Cullen, B F; Murphy, M E; Welch, W D

1982-03-01

The effects of aspiration of (a) 2 ml of Mylanta (a particulate antacid) mixed with 2 ml of hydrochloric acid (pH 1.5), (b) 2 ml of half-strength Bicitra (a soluble antacid) mixed with 2 ml of hydrochloric acid (pH 1.5), (c) 4 ml of hydrochloric acid (pH 1.5), and (d) 4 ml of normal saline (pH 6.5) on arterial blood gas tensions and lung pathology were compared in anesthetized rabbits. PaO2 decreased similarly in all animals 15 minutes after aspiration, but recovered to normal levels 4 hours after aspiration of saline and 48 hours after aspiration of Bicitra. PaO2 remained depressed after aspiration of Mylanta and HCl. Gross and microscopic evidence of lung injury was most severe in animals that aspirated Mylanta. One animal died 8 hours after aspiration of Mylanta.

A Randomized Trial Among Compression Plus Nonsteroidal Antiinflammatory Drugs, Aspiration, and Aspiration With Steroid Injection for Nonseptic Olecranon Bursitis.

PubMed

Kim, Joon Yub; Chung, Seok Won; Kim, Joo Hak; Jung, Jae Hong; Sung, Gwang Young; Oh, Kyung-Soo; Lee, Jong Soo

2016-03-01

Olecranon bursitis might be a minor problem in the outpatient clinic but relatively be common to occur. However, there are few well-designed studies comparing approaches to treatment. (1) Which treatment (compression bandaging with nonsteroidal antiinflammatory drugs [NSAIDs], aspiration, or aspiration with steroid injections) is associated with the highest likelihood of resolution of nonseptic olecranon bursitis? (2) Which treatment is associated with earliest resolution of symptoms? (3) What factors are associated with treatment failure by 4 weeks? We enrolled 133 patients from two centers; after applying prespecified exclusions (septic bursitis or concomitant inflammatory arthritis, intraarticular elbow pathology, recent aspiration or steroid injection done elsewhere, and refusal to participate), 90 patients were randomly allocated to receive compression bandaging with NSAIDs (C), aspiration (A), or aspiration with steroid injection (AS) groups (30 patients in each). The groups were similar at baseline in terms of age and gender. Seven patients (four from Group A and three from Group AS) were lost to followup. All patients were followed up weekly for 4 weeks, and the same treatment procedure was repeated if the bursitis recurred with any substantial fluid collection. At 4 weeks, the state of resolution and pain visual analog scale (VAS) were evaluated. Failed resolution was defined as presence of persistent olecranon bursal fluid collection at Week 4 after the initiation of the treatment; on the contrary, if bursal fluid collection was clinically reduced or completely disappeared by the end of Week 4, the treatment was considered successful. We compared the proportion of resolution by Week 4 and the median times to resolution among the treatment groups. In addition, we evaluated whether the resolution affected pain VAS and what factors were associated with the resolution. There were no differences in the proportion of patients whose bursitis resolved by Week 4

[A retrospective clinicopathological study of aspiration pneumonia in the elderly].

PubMed

Pu, Chun; Zhong, Xuefeng; Fang, Fang; Yang, Yimeng; Xu, Xiaomao; Sun, Tieying

2014-08-01

To explore the clinicopathological characteristics of aspiration pneumonia in the elderly. The clinical data of 30 cases of autopsy-proven aspiration pneumonia in Beijing Hospital from 1973 to 2002 were reviewed. The patients consisted of 28 males and 2 females, aged from 63 to 103 [mean (83 ± 9)] years. Only 15 cases were clinically diagnosed as aspiration pneumonia before death. Concomitant diseases were severe and complex, mostly coronary disease, cerebrovascular disease, hypertension, COPD, and diabetes mellitus. All the patients suffered from at least 3 concomitant diseases. Long-term bedridden and nasogastric feeding was seen in 11 and 17 patients respectively. The clinical presentation and chest X-ray of aspiration pneumonia in the elderly were nonspecific and variable. Mixed infections were common . The main bacteria isolated were Gram-negative bacilli, in particular Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Escherichia coli and Candida albicans. By pathology, macrophages with foreign bodies were found in all the 30 cases and multiple small abscesses were found in 14 cases. The lesions were adjacent to the bronchioles and in the lung tissue around the bronchioles, mostly multi-lobar and bilateral. Unilateral or bilateral pleural effusion developed in 20 patients. The accordance between radiological and pathological diagnosis of aspiration pneumonia was very poor. The foci of infection detected by X-ray were proven by autopsy in 13 patients, while pleural effusions in X-ray were proven by autopsy in 15 patients. Multi-concomitant diseases, mixed infection and extra-pulmonary presentations were common in elderly patients with aspiration pneumonia. Multiple small abscesses were the pathological characteristics of aspiration pneumonia in the aged. A definite clinical diagnosis of aspiration pneumonia was difficult. Recurrent silent microaspiration was a feature of aspiration in the elderly. The assessment of risk factor of aspiration played an

Aspiration pneumonia after concurrent chemoradiotherapy for head and neck cancer.

PubMed

Xu, Beibei; Boero, Isabel J; Hwang, Lindsay; Le, Quynh-Thu; Moiseenko, Vitali; Sanghvi, Parag R; Cohen, Ezra E W; Mell, Loren K; Murphy, James D

2015-04-15

Aspiration pneumonia represents an under-reported complication of chemoradiotherapy in patient with head and neck cancer. The objective of the current study was to evaluate the incidence, risk factors, and mortality of aspiration pneumonia in a large cohort of patients with head and neck cancer who received concurrent chemoradiotherapy. Patients who had head and neck cancer diagnosed between 2000 and 2009 were identified from the Surveillance, Epidemiology, and End Results-Medicare database. Aspiration pneumonia was identified from Medicare billing claims. The cumulative incidence, risk factors, and survival after aspiration pneumonia were estimated and compared with a noncancer population. Of 3513 patients with head and neck cancer, 801 developed aspiration pneumonia at a median of 5 months after initiating treatment. The 1-year and 5-year cumulative incidence of aspiration pneumonia was 15.8% and 23.8%, respectively, for patients with head and neck cancer and 3.6% and 8.7%, respectively, for noncancer controls. Among the patients with cancer, multivariate analysis identified independent risk factors (P < .05) for aspiration pneumonia, including hypopharyngeal and nasopharyngeal tumors, male gender, older age, increased comorbidity, no surgery before radiation, and care received at a teaching hospital. Among the patients with cancer who experienced aspiration pneumonia, 674 (84%) were hospitalized; and, of these, 301 (45%) were admitted to an intensive care unit. The 30-day mortality rate after hospitalization for aspiration pneumonia was 32.5%. Aspiration pneumonia was associated with a 42% increased risk of death (hazard ratio, 1.42; P < .001) after controlling for confounders. The current results indicated that nearly 25% of elderly patients will develop aspiration pneumonia within 5 years after receiving chemoradiotherapy for head and neck cancer. A better understanding of mitigating factors will help identify patients who are at risk for this potentially

Occupational aspirations of black South African adolescents.

PubMed

Watson, M B; Foxcroft, C D; Horn, M A; Stead, G B

1997-04-01

The present study provides a description of the occupational aspirations of 216 black high school students in a special program by the amount of training required (status) and Holland's 1973 typology as well as by gender, age, socioeconomic status, knowledge of self, and occupational knowledge. Analysis indicates that most adolescents aspire to Social and Investigative occupations, and occupations with a high status. Most of this select sample displayed low self- and occupational knowledge. Aspirations appear unrealistic in terms of trends within the labor market, but might be more realistic with effective and relevant guidance programs in schools.

Proximal suction tracheotomy tube reduces aspiration volume.

PubMed

Coffman, Heather M S; Rees, Catherine J; Sievers, Ann E F; Belafsky, Peter C

2008-04-01

Conventional cuffed tracheotomy tubes do not prevent aspiration of secretions. Aspiration of saliva may be decreased with the use of a subglottic suction port. Prospective. Shiley Disposable Cuffed Tracheotomy (DCT) tubes sizes 4, 6, and 8 (Tyco Healthcare, Pleasanton, CA) were compared to Portex Blue Line Ultra Suctionaid (BLUS) tracheotomy tubes sizes 6, 7, and 8 (Fig 1; Smiths Medical, Watford, UK). All tubes were tested in a simulated tracheal model using 10 cc of human saliva with no suction, intermittent suction, and constant suction (15 minutes). There was a significant decrease in aspirate between the larger Shiley and BLUS tubes with intermittent suction (mean 8.38 mL Shiley 6 vs 1.60 mL BLUS 7; 8.50 mL Shiley 8 vs 2.80 mL BLUS 8). There was a significant decrease in aspirate between all sizes of Shiley and BLUS tubes with continuous suction. For BLUS 7 and 8, there was a significant difference between intermittent suction (mean, 1.60 mL, 2.80 mL, respectively) and continuous suction (mean, 0.20 mL, 0.60 mL respectively). Shiley and BLUS without suction were equivalent. Subglottic suction tracheotomy tubes reduce the risk of aspiration beyond the cuff in a bench-top model.

Foreign body aspiration in children: A study of children who lived or died following aspiration.

PubMed

Mohammad, Maha; Saleem, Mohammad; Mahseeri, Mohamad; Alabdallat, Imad; Alomari, Ali; Za'atreh, Ala'; Qudaisat, Ibraheem; Shudifat, Abdulrahman; Nasri Alzoubi, Mohammad

2017-07-01

Foreign body aspiration (FBA) is a preventable cause of mortality and morbidity in children. We conducted a chart review of children who presented to a university hospital due to FBA in the period 1999-2014. Children were either managed with bronchoscopy for removal of the foreign body or died due to FBA. A total of 103 children were seen due to FBA including 27 deaths. The majority of children were boys and were less than 3 years old. Most aspirated foreign bodies were food-related, mainly peanuts. The majority of children presented with acute choking incidents, a smaller number presented with recurrent chest infections, and few children's choking incidents were unwitnessed. X-ray had a high rate of false negatives and bronchoscopy was the gold standard technique for assessment and management. Aspiration of foreign bodies is a preventable, life-threatening condition that calls for increased parent education and awareness. Copyright © 2017 Elsevier B.V. All rights reserved.

Multi-template analysis of human perirhinal cortex in brain MRI: Explicitly accounting for anatomical variability

PubMed Central

Xie, Long; Pluta, John B.; Das, Sandhitsu R.; Wisse, Laura E.M.; Wang, Hongzhi; Mancuso, Lauren; Kliot, Dasha; Avants, Brian B.; Ding, Song-Lin; Manjón, José V.; Wolk, David A.; Yushkevich, Paul A.

2016-01-01

Rational The human perirhinal cortex (PRC) plays critical roles in episodic and semantic memory and visual perception. The PRC consists of Brodmann areas 35 and 36 (BA35, BA36). In Alzheimer's disease (AD), BA35 is the first cortical site affected by neurofibrillary tangle pathology, which is closely linked to neural injury in AD. Large anatomical variability, manifested in the form of different cortical folding and branching patterns, makes it difficult to segment the PRC in MRI scans. Pathology studies have found that in ~97% of specimens, the PRC falls into one of three discrete anatomical variants. However, current methods for PRC segmentation and morphometry in MRI are based on single-template approaches, which may not be able to accurately model these discrete variants Methods A multi-template analysis pipeline that explicitly accounts for anatomical variability is used to automatically label the PRC and measure its thickness in T2-weighted MRI scans. The pipeline uses multi-atlas segmentation to automatically label medial temporal lobe cortices including entorhinal cortex, PRC and the parahippocampal cortex. Pairwise registration between label maps and clustering based on residual dissimilarity after registration are used to construct separate templates for the anatomical variants of the PRC. An optimal path of deformations linking these templates is used to establish correspondences between all the subjects. Experimental evaluation focuses on the ability of single-template and multi-template analyses to detect differences in the thickness of medial temporal lobe cortices between patients with amnestic mild cognitive impairment (aMCI, n=41) and age-matched controls (n=44). Results The proposed technique is able to generate templates that recover the three dominant discrete variants of PRC and establish more meaningful correspondences between subjects than a single-template approach. The largest reduction in thickness associated with aMCI, in absolute terms

The "Placetimemattering" of Aspiration in the Blacktown Learning Community

ERIC Educational Resources Information Center

Somerville, Margaret

2013-01-01

The aim of this article is to explore aspiration in contemporary urban locations in the context of almost universal policy initiatives to raise aspirations of young people to participate in higher education. The article is based on a study of how children's career and further education aspirations are shaped over time in five schools in western…

Pulmonary aspiration of gastric contents during routine endoscopy

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

La France, N.D.; Cole, P.; Wolfe, E.

Radioactive tracer studies are a sensitive means to detect occult pulmonary aspiration of gastric contents. A complication of diagnostic endoscopy is aspiration of contents even in fasted patients. The authors have studied 21 hospitalized patients who underwent elective endoscopy (END) for suspected UGI pathology. Fifteen minutes before END, and prior to pharygeal anesthesia, 1 mCi Tc-99m-sulfur colloid, added to the usual 30cc of simethicone routinely administered before END, was given orally. END was performed as usual and 2 hours later anterior 100,000 count images of the chest were obtained. All the studies were interpreted without history or clinical information. Fevermore » developed within 24 hours (and septic shock in 1) in both patients with positive studies while no fever occurred in the remaining patients with negative studies (rho<.001). The authors conclude that oral radionuclide pulmonary aspiration studies may; detect aspiration not recognized by the endoscopist, reveal evidence of aspiration that preceeds adverse clinical signs and symptoms, and be influenced by systemic pre-END drugs known to affect GI secretions and motility.« less

Age- and Brain Region-Specific Changes of Glucose Metabolic Disorder, Learning, and Memory Dysfunction in Early Alzheimer's Disease Assessed in APP/PS1 Transgenic Mice Using 18F-FDG-PET.

PubMed

Li, Xue-Yuan; Men, Wei-Wei; Zhu, Hua; Lei, Jian-Feng; Zuo, Fu-Xing; Wang, Zhan-Jing; Zhu, Zhao-Hui; Bao, Xin-Jie; Wang, Ren-Zhi

2016-10-18

Alzheimer's disease (AD) is a leading cause of dementia worldwide, associated with cognitive deficits and brain glucose metabolic alteration. However, the associations of glucose metabolic changes with cognitive dysfunction are less detailed. Here, we examined the brains of APP/presenilin 1 (PS1) transgenic (Tg) mice aged 2, 3.5, 5 and 8 months using 18 F-labed fluorodeoxyglucose ( 18 F-FDG) microPET to assess age- and brain region-specific changes of glucose metabolism. FDG uptake was calculated as a relative standardized uptake value (SUVr). Morris water maze (MWM) was used to evaluate learning and memory dysfunction. We showed a glucose utilization increase in multiple brain regions of Tg mice at 2 and 3.5 months but not at 5 and 8 months. Comparisons of SUVrs within brains showed higher glucose utilization than controls in the entorhinal cortex, hippocampus, and frontal cortex of Tg mice at 2 and 3.5 months but in the thalamus and striatum at 3.5, 5 and 8 months. By comparing SUVrs in the entorhinal cortex and hippocampus, Tg mice were distinguished from controls at 2 and 3.5 months. In MWM, Tg mice aged 2 months shared a similar performance to the controls (prodromal-AD). By contrast, Tg mice failed training tests at 3.5 months but failed all MWM tests at 5 and 8 months, suggestive of partial or complete cognitive deficits (symptomatic-AD). Correlation analyses showed that hippocampal SUVrs were significantly correlated with MWM parameters in the symptomatic-AD stage. These data suggest that glucose metabolic disorder occurs before onset of AD signs in APP/PS1 mice with the entorhinal cortex and hippocampus affected first, and that regional FDG uptake increase can be an early biomarker for AD. Furthermore, hippocampal FDG uptake is a possible indicator for progression of Alzheimer's cognition after cognitive decline, at least in animals.

Gendered Trends in Student Teachers' Professional Aspirations

ERIC Educational Resources Information Center

Smith, Joan

2015-01-01

The paper reports on a small-scale, exploratory study investigating the professional aspirations of a cohort of student teachers at a UK university. Questionnaires and interviews sought insights into the students' perceptions of leadership, future aspirations and self-perceptions as potential leaders. Whilst there was commonality in male and…

Dynamic interneuron-principal cell interplay leads to a specific pattern of in vitro ictogenesis.

PubMed

Lévesque, Maxime; Chen, Li-Yuan; Hamidi, Shabnam; Avoli, Massimo

2018-07-01

Ictal discharges induced by 4-aminopyridine in the in vitro rodent entorhinal cortex present with either low-voltage fast or sudden onset patterns. The role of interneurons in initiating low-voltage fast onset ictal discharges is well established but the processes leading to sudden onset ictal discharges remain unclear. We analysed here the participation of interneurons (n = 75) and principal cells (n = 13) in the sudden onset pattern by employing in vitro tetrode wire recordings in the entorhinal cortex of brain slices from Sprague-Dawley rats. Ictal discharges emerged from a background of frequently occurring interictal spikes that were associated to a specific interneuron/principal cell interplay. High rates of interneuron firing occurred 12 ms before interictal spike onset while principal cells fired later during low interneuron firing. In contrast, the onset of sudden ictal discharges was characterized by increased firing from principal cells 627 ms before ictal onset whereas interneurons increased their firing rates 161 ms before ictal onset. Our data show that sudden onset ictogenesis is associated with frequently occurring interictal spikes resting on the interplay between interneurons and principal cells while ictal discharges stem from enhanced principal cell firing leading to increased interneuron activity. These findings indicate that specific patterns of interactions between interneurons and principal cells shape interictal and ictal discharges with sudden onset in the rodent entorhinal cortex. We propose that specific neuronal interactions lead to the generation of distinct onset patterns in focal epileptic disorders. Copyright © 2018 Elsevier Inc. All rights reserved.

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women.

PubMed

Leicht, Carola; Gocłowska, Małgorzata A; Van Breen, Jolien A; de Lemus, Soledad; Randsley de Moura, Georgina

2017-01-01

Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1) counter-stereotype salience and (2) feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadership aspirations contingent on a high level of feminist identification. In our study US-based women ( N = 208) attended to gender stereotypic (vs. counter-stereotypic) content. We measured identification with women and identification with feminism, and, following the manipulation, leadership aspirations in an imagined work scenario. The interaction between identification with women, identification with feminism, and attention to stereotypes (vs. counter-stereotypes) significantly predicted leadership aspirations. In the counter-stereotypic condition women's identification associated with greater leadership aspirations regardless of feminist identification. In the stereotypic condition women's identification predicted leadership aspirations only at high levels of feminist identification. We conclude that salient counter-stereotypes and a strong identification with feminism may help high women identifiers increase their leadership aspirations.

Counter-Stereotypes and Feminism Promote Leadership Aspirations in Highly Identified Women

PubMed Central

Leicht, Carola; Gocłowska, Małgorzata A.; Van Breen, Jolien A.; de Lemus, Soledad; Randsley de Moura, Georgina

2017-01-01

Although women who highly identify with other women are more susceptible to stereotype threat effects, women's identification might associate with greater leadership aspirations contingent on (1) counter-stereotype salience and (2) feminist identification. When gender counter-stereotypes are salient, women's identification should associate with greater leadership aspiration regardless of feminism, while when gender stereotypes are salient, women's identification would predict greater leadership aspirations contingent on a high level of feminist identification. In our study US-based women (N = 208) attended to gender stereotypic (vs. counter-stereotypic) content. We measured identification with women and identification with feminism, and, following the manipulation, leadership aspirations in an imagined work scenario. The interaction between identification with women, identification with feminism, and attention to stereotypes (vs. counter-stereotypes) significantly predicted leadership aspirations. In the counter-stereotypic condition women's identification associated with greater leadership aspirations regardless of feminist identification. In the stereotypic condition women's identification predicted leadership aspirations only at high levels of feminist identification. We conclude that salient counter-stereotypes and a strong identification with feminism may help high women identifiers increase their leadership aspirations. PMID:28626437

Predictors of radiolucent foreign body aspiration.

PubMed

Mortellaro, Vincent E; Iqbal, Corey; Fu, Roxanna; Curtis, Heather; Fike, Frankie B; St Peter, Shawn D

2013-09-01

Children frequently present for suspected foreign body aspiration, many have mild symptoms and/or negative radiographs raising the question of a radiolucent foreign body aspiration. Retrospective review of patients having bronchoscopy for suspected radiolucent foreign body aspiration from 2000 to 2010 collecting demographics, history, hospital presentation, radiographic, and operative details. Pearson's correlation was used between event history, presentation, radiographic details and bronchoscopically identified foreign body with P value <0.01. 138 patients, mean age 2.6 years, mean weight 15.6 kg, 68% male. Event symptoms: 81% witnessed events, 64% wheezing, 43% coughing, 39% choking, 6% stridor, and 0.7% lethargy. Hospital presentation: 70% persistent symptoms, wheezing 56%, coughing 15%, desaturations 11%, stridor 7%, choking 4%, and lethargy 1%. 92% of patients had a chest x-ray; air trapping found in 38%, and lung collapse in 21%. 2 patients received CT scans; 1 had lung collapse. Bronchoscopy identified foreign bodies in 93% of patients: food 68%, plastic 18%, non-descript 11%, rocks 3%. No correlations between event symptoms, hospital presentation, radiographs and foreign body presence. Event history, hospital presentation, and radiographs are insufficient in proving the absence of a radiolucent foreign body. Patients with suspected radiolucent foreign body aspiration should undergo diagnostic bronchoscopy prior to discharge. Copyright © 2013 Elsevier Inc. All rights reserved.

Aspiration dynamics of multi-player games in finite populations

PubMed Central

Du, Jinming; Wu, Bin; Altrock, Philipp M.; Wang, Long

2014-01-01

On studying strategy update rules in the framework of evolutionary game theory, one can differentiate between imitation processes and aspiration-driven dynamics. In the former case, individuals imitate the strategy of a more successful peer. In the latter case, individuals adjust their strategies based on a comparison of their pay-offs from the evolutionary game to a value they aspire, called the level of aspiration. Unlike imitation processes of pairwise comparison, aspiration-driven updates do not require additional information about the strategic environment and can thus be interpreted as being more spontaneous. Recent work has mainly focused on understanding how aspiration dynamics alter the evolutionary outcome in structured populations. However, the baseline case for understanding strategy selection is the well-mixed population case, which is still lacking sufficient understanding. We explore how aspiration-driven strategy-update dynamics under imperfect rationality influence the average abundance of a strategy in multi-player evolutionary games with two strategies. We analytically derive a condition under which a strategy is more abundant than the other in the weak selection limiting case. This approach has a long-standing history in evolutionary games and is mostly applied for its mathematical approachability. Hence, we also explore strong selection numerically, which shows that our weak selection condition is a robust predictor of the average abundance of a strategy. The condition turns out to differ from that of a wide class of imitation dynamics, as long as the game is not dyadic. Therefore, a strategy favoured under imitation dynamics can be disfavoured under aspiration dynamics. This does not require any population structure, and thus highlights the intrinsic difference between imitation and aspiration dynamics. PMID:24598208

Aspiration dynamics of multi-player games in finite populations.

PubMed

Du, Jinming; Wu, Bin; Altrock, Philipp M; Wang, Long

2014-05-06

On studying strategy update rules in the framework of evolutionary game theory, one can differentiate between imitation processes and aspiration-driven dynamics. In the former case, individuals imitate the strategy of a more successful peer. In the latter case, individuals adjust their strategies based on a comparison of their pay-offs from the evolutionary game to a value they aspire, called the level of aspiration. Unlike imitation processes of pairwise comparison, aspiration-driven updates do not require additional information about the strategic environment and can thus be interpreted as being more spontaneous. Recent work has mainly focused on understanding how aspiration dynamics alter the evolutionary outcome in structured populations. However, the baseline case for understanding strategy selection is the well-mixed population case, which is still lacking sufficient understanding. We explore how aspiration-driven strategy-update dynamics under imperfect rationality influence the average abundance of a strategy in multi-player evolutionary games with two strategies. We analytically derive a condition under which a strategy is more abundant than the other in the weak selection limiting case. This approach has a long-standing history in evolutionary games and is mostly applied for its mathematical approachability. Hence, we also explore strong selection numerically, which shows that our weak selection condition is a robust predictor of the average abundance of a strategy. The condition turns out to differ from that of a wide class of imitation dynamics, as long as the game is not dyadic. Therefore, a strategy favoured under imitation dynamics can be disfavoured under aspiration dynamics. This does not require any population structure, and thus highlights the intrinsic difference between imitation and aspiration dynamics.

Pushing the Limits: The Female Administrative Aspirant.

ERIC Educational Resources Information Center

Edson, Sakre Kennington

The results of a longitudinal study of women pursuing administrative careers provides a fuller understanding of the motivations of women and assists aspiring women in making informed career choices. The book has five sections. The first covers career stages common to most aspirants, but from a female perspective. In the second section, women…

Tracheobronchial foreign body aspiration in children.

PubMed

Burton, E M; Brick, W G; Hall, J D; Riggs, W; Houston, C S

1996-02-01

In this retrospective study, we reviewed the demographic and radiographic findings of 155 children with bronchoscopy-proven tracheobronchial foreign body aspiration (FBA). Two thirds of the patients were male, and most were children between 1 and 2 years of age. An aspirated peanut accounted for one third of all cases. Foreign body location was distributed nearly evenly to the right and left primary bronchi; tracheal foreign body was noted in 16 patients. The most frequent symptoms of FBA were cough (85 patients) and wheezing (60 patients). Although most patients were seen within 1 day of aspiration, 30 patients had symptoms that lasted at least 1 week before diagnosis. The most common radiographic findings were unilateral or segmental hyperlucency (59) or atelectasis (38). The trachea was the site of the foreign body in one half of children with a normal chest radiograph and FBA.

Transvaginal Aspiration of Ovarian Cysts: Long-Term Follow-up

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

Duke, D.; Colville, J.; Keeling, A.

2006-06-15

Background and purpose. Transvaginal aspiration of ovarian cysts has been advocated as a viable alternative to surgery in patients who are high-risk surgical candidates. We describe a retrospective study evaluating the results of transvaginal aspirations of benign ovarian cysts in patients at increased surgical risk, focusing on long-term follow-up for recurrence of the cyst and/or development of malignancy. Methods. Twenty-four women with ovarian cysts underwent 34 transvaginal drainages between October 1998 and December 2004. All patients were referred following diagnosis of a persistent ovarian cyst with a benign appearance on ultrasound. All patients were unsuitable candidates for surgery (history ofmore » previous pelvic surgery, n = 21; high risk for anesthesia, n = 1; and unsuitable for laparoscopy due to obesity, n = 2). Patients with a history of pregnancy, acute abdominal symptoms, or previous gynecologic malignancy were excluded. A 20G x 20 cm Chiba needle was used for transvaginal aspiration using an endocavity probe (Acuson XP, Mountain View, CA, USA; Siemens Sololine, Erlangen, Germany) and intravenous sedoanalgesia. Cysts were aspirated to dryness. Results. Long-term follow-up of patients was performed and revealed a recurrence rate of 75%. Eighty-three percent of cysts on the left and 42% of those on the right recurred. Nine of 15 (60%) patients with recurrence required further intervention. Two of 9 underwent surgical intervention only, 4 of 9 had repeat transvaginal aspiration(s) performed, and 3 of 9 had a combination of both transvaginal aspiration and surgery. No patient developed ovarian malignancy. Conclusion. Transvaginal cyst aspiration has many advantages including short hospital stay, rapid recovery, excellent patient tolerance, and a low rate of procedure-related complications. Our study demonstrates that ovarian cyst recurrence following transvaginal drainage is a more significant problem than previously documented, especially if the

Undergraduate Women's Gender Awareness and Status Aspirations.

ERIC Educational Resources Information Center

Inoue, Yukiko

A study was conducted to determine women's realization toward the quality of life, identifying their status aspirations. The study's primary purpose was to achieve a better understanding of how undergraduate women of Guam and Japan would aspire to their academic and social goals and how they would become aware of their gender equality. The…

Commodity aspirations in Easterlin's relative income theory of fertility.

PubMed

Ahlburg, D A

1984-01-01

This paper presents the preference ordering that underlies Easterlin's relative income theory of fertility. Commodity aspirations are a key component of the theory and the paper explores how the introduction of commodity aspirations into the utility function affects the consumption of commodities and bearing of children. The formation and empirical specification of commodity aspirations are also discussed. Commodity aspirations are formed by the material environment experienced during childhood and are primarily a function of parental income. Easterlin, Leibenstein and Ben-Porath argus that it is the parental consumption or standard of living that determines the child's testes or aspirations. It is the parents' spending on themseleves rather than total parental income that can be used as a proxy for the child's commodity aspirations. Bagozzi and Van Loo identify 4 significant contributions made by Easterlinhs theory of fertility. They cite his stress on potential income flow through time as being pertinent to household decision making; tastes being an explicit determinant of fertility; background charactersticis and norms as to standards of child care and family size affecting fertility indirectly through tastes rather than directly; and the fact that relative income has an effect on fertility in addition to the influence of the absolute level of income. The number of children demanded is a negative function of commodity aspirations, as is the utility of the family. Studies of the demand for commodities and children should include data on parental resources.

Airway obstruction due to aspiration of muddy water.

PubMed

Schober, Patrick; Christiaans, Herman M T; Loer, Stephan A; Schwarte, Lothar A

2013-10-01

We report a case of complete airway obstruction due to aspiration of muddy water. An innovative approach to clear the airway is described, which may be a potentially life saving manoeuver in similar cases of suspected muddy water aspiration.

Aspiration of breast abscess through wide bore 14-gauge intravenous cannula.

PubMed

Afridi, Shahida Parveen; Alam, Shams Nadeem; Ainuddin, Saman

2014-10-01

To aspirate breast abscess through a wide bore (14-gauge) intravenous (I/V) cannula and determine its efficacy in terms of the number of recurrences and number of aspirations. Case series. Dow University of Health Sciences and Civil Hospital and Bantva Hospital, Karachi, Pakistan, from January 2009 to December 2011. Patients with breast abscesses confirmed on ultrasound without skin ulceration were selected. The soft area of breast abscess with positive fluctuation was marked and fixed with index finger and thumb. A 14-gauge cannula was inserted. Pus was aspirated through a 50 cc syringe, repeated till no aspirate could be obtained. All patients were followed weekly for 4 weeks, clinically for size of lump, local tenderness and temperature, while complete resolution was confirmed on ultrasound, as resolution of the lesion. A total of 55 patients were included in this study. Mean age was 29 ± 5.58 years while ranging from 20 - 40 years. Complete resolution of abscess was seen in 31 (56.4%) cases by single aspiration. Second aspiration was required in 24 (43.6%) patients and third aspiration in single setting was required in one case only. Recurrence after the second aspiration occurred in 08 (14.5%). Incision drainage was required in 7 (12.7%) patients. Percutaneous aspiration of breast abscess through a wide bore (14-gauge) I/V cannula is a simple alternative to incision and drainage.

Predicted sequence of cortical tau and amyloid-β deposition in Alzheimer disease spectrum.

PubMed

Cho, Hanna; Lee, Hye Sun; Choi, Jae Yong; Lee, Jae Hoon; Ryu, Young Hoon; Lee, Myung Sik; Lyoo, Chul Hyoung

2018-04-17

We investigated sequential order between tau and amyloid-β (Aβ) deposition in Alzheimer disease spectrum using a conditional probability method. Two hundred twenty participants underwent 18 F-flortaucipir and 18 F-florbetaben positron emission tomography scans and neuropsychological tests. The presence of tau and Aβ in each region and impairment in each cognitive domain were determined by Z-score cutoffs. By comparing pairs of conditional probabilities, the sequential order of tau and Aβ deposition were determined. Probability for the presence of tau in the entorhinal cortex was higher than that of Aβ in all cortical regions, and in the medial temporal cortices, probability for the presence of tau was higher than that of Aβ. Conversely, in the remaining neocortex above the inferior temporal cortex, probability for the presence of Aβ was always higher than that of tau. Tau pathology in the entorhinal cortex may appear earlier than neocortical Aβ and may spread in the absence of Aβ within the neighboring medial temporal regions. However, Aβ may be required for massive tau deposition in the distant cortical areas. Copyright © 2018 Elsevier Inc. All rights reserved.

Cross-Lagged Relationships between Career Aspirations and Goal Orientation in Early Adolescents

ERIC Educational Resources Information Center

Creed, Peter; Tilbury, Clare; Buys, Nick; Crawford, Meegan

2011-01-01

We surveyed 217 students (145 girls; average age = 14.6 years) on two occasions, twelve months apart, on measures of career aspirations (job aspirations, job expectations, educational aspirations) and goal orientation (learning, performance-prove, performance-avoid), and tested the causal relationship between goal orientation and aspirations. We…

Cell-type specific circuit connectivity of hippocampal CA1 revealed through Cre-dependent rabies tracing

PubMed Central

Sun, Yanjun; Nguyen, Amanda; Nguyen, Joseph; Le, Luc; Saur, Dieter; Choi, Jiwon; Callaway, Edward M.; Xu, Xiangmin

2014-01-01

Summary We applied a new Cre-dependent, genetically modified rabies-based tracing system to map direct synaptic connections to CA1 excitatory and inhibitory neuron types in mouse hippocampus. We found common inputs to excitatory and inhibitory CA1 neurons from CA3, CA2, entorhinal cortex and the medial septum (MS), and unexpectedly also from the subiculum. Excitatory CA1 neurons receive inputs from both cholinergic and GABAergic MS neurons while inhibitory CA1 neurons receive a great majority of input from GABAergic MS neurons; both cell types also receive weaker input from glutamatergic MS neurons. Comparisons of inputs to CA1 PV+ interneurons versus SOM+ interneurons showed similar strengths of input from the subiculum, but PV+ interneurons receive much stronger input than SOM+ neurons from CA3, entorhinal cortex and MS. Differential input from CA3 to specific CA1 cell types was also demonstrated functionally using laser scanning photostimulation and whole cell recordings. PMID:24656815

Ketone bodies do not directly alter excitatory or inhibitory hippocampal synaptic transmission.

PubMed

Thio, L L; Wong, M; Yamada, K A

2000-01-25

To determine the effect of the ketone bodies beta-hydroxybutyrate (betaHB) and acetoacetate (AA) on excitatory and inhibitory neurotransmission in the mammalian CNS. The ketogenic diet is presumed to be an effective anticonvulsant regimen for some children with medically intractable seizures. However, its mechanism of action remains a mystery. According to one hypothesis, ketone bodies have anticonvulsant properties. The authors examined the effect of betaHB and AA on excitatory and inhibitory synaptic transmission in rat hippocampal-entorhinal cortex slices and cultured hippocampal neurons. In cultured neurons, their effect was also directly assayed on postsynaptic receptor properties. Finally, their ability to prevent spontaneous seizures was determined in a hippocampal-entorhinal cortex slice model. betaHB and AA did not alter synaptic transmission in these models. The anticonvulsant properties of the ketogenic diet do not result from a direct effect of ketone bodies on the primary voltage and ligand gated ion channels mediating excitatory or inhibitory neurotransmission in the hippocampus.

Aspiration lung disorders in bovines: a case report and review.

PubMed

Shakespeare, Anthony S

2012-11-01

Lung aspiration disorders in bovines are invariably diagnosed as infectious aspiration pneumonias. There is a distinct differentiation between aspiration pneumonia and aspiration pneumonitis in humans that can be applied to bovines. The nature and quantity of the aspirate can result in differing pathogeneses which can require differing therapeutic approaches. Whilst blood gases were important in detecting and prognosticating lung problems, changes in barometric pressure with altitude have to be considered when interpreting partial pressures of oxygen. Anatomical differences in the lungs of bovines can explain why this species is more prone to certain pneumonic problems. Pulmonary physiotherapy is important in treating lung disorders in humans and should be considered as an adjunct therapy in bovine respiratory conditions. A case work-up was used to highlight some of the points discussed in this article.

Short article: Aspiration of capsule endoscopes: a comprehensive review of the existing literature.

PubMed

Yung, Diana E; Plevris, John N; Koulaouzidis, Anastasios

2017-04-01

Capsule endoscopy (CE) has an excellent safety profile. Although retention is the most cited complication, capsule aspiration is less frequent and is often reported only as isolated cases. This study represents a systematic effort to compile and scrutinize the available data on capsule aspiration to provide comprehensive and conclusive information on this CE complication. A systematic literature search was performed in PubMed, Embase and Chinese National Knowledge Infrastructure. The search terms used were 'capsule endoscopy' AND 'aspiration' (both terms searched as keyword and MeSH). We included case reports and/or series on capsule aspiration, as well as observational cohort studies that reported capsule aspiration among their complications/outcomes. Thirty-four case reports with 37 cases of capsule aspiration were identified. A further four observational studies reported aspiration as part of a cohort of patients undergoing CE. 94.6% of aspirations occurred in elderly men. 87.1% had significant comorbidities. 59.5% had symptoms on aspiration, with cough reported most frequently. The most common location of aspiration was the right main bronchus. Half of the patients required intervention for capsule retrieval; bronchoscopy was the most common management, with good effect. There was a single fatality following capsule aspiration, not directly related to the procedure, and one case of aspiration pneumonia. Outcomes were good for all other patients. The estimated overall aspiration rate is 0.1%. Although very rare and generally safely managed, capsule aspiration should be anticipated in certain patient groups and capsule administration should be approached with necessary precautions.

Ingested and Aspirated Foreign Bodies.

PubMed

Green, S Sarah

2015-10-01

Esophageal and aspirated foreign bodies have important clinical significance, and both should be considered carefully when the history or physical examination findings raise sufficient suspicion. The published evidence regarding the diagnosis and management of foreign body ingestion or aspiration is weighted disproportionately with observational studies, case controls, expert opinion, and systematic reviews. Most of the publications would receive a categorization of C (observational studies including case-control and cohort design) and D (expert opinion, case reports, and clinical reasoning). One of the few prospective studies examining the diagnostic evaluation of foreign body aspiration in children could be considered level B evidence (randomized clinical trials, systematic reviews, or diagnostic studies with minor limitations). This study found that the medical history is the most important predictive part of the evaluation. There is evidence for considering bronchoscopy if there is significant history suggestive of foreign body aspiration, even in the setting of normal physical examination findings. (28). Most ingested foreign bodies spontaneously pass without incident. However, special attention should be paid to objects in the esophagus as well as to batteries and magnets. Based on a systematic review of the literature (level B evidence) and the potential for rapid and life-threatening damage, batteries in the esophagus should be removed immediately. (10) Other objects, such as coins, may be observed for passage in an asymptomatic patient. In addition, given the high risk of significant complications, ingestion of high-powered magnets should be quickly and carefully evaluated. Although single magnets are likely to pass without complication, multiple magnets or magnets ingested with other metal objects can cause significant damage and should be removed if there is any concern for mural entrapment, bowel perforation, or failure to progress. (10

Keeping Up with the Joneses: Friends' Perfectionism and Students' Orientation Toward Extrinsic Aspirations.

PubMed

Hope, Nora; Koestner, Richard; Holding, Anne; Harvey, Brenda

2016-12-01

Kasser and Ryan (1993,1996) have contrasted two types of life values: intrinsic aspirations, which include community contribution, building close relationships, and self-growth, and extrinsic aspirations, which include fame, wealth, and physical beauty. Prioritization of extrinsic relative to intrinsic aspirations has been related cross-sectionally to decreased well-being (Kasser, 2002). However, the influence of close others in the etiology of young adults' prioritization of extrinsic aspirations, and the prospective effects of aspirations on well-being, are not well understood. In a multiple-informant prospective study of 341 university students (mean age = 19.4; 64% Caucasian; 74% female), we examined the influence of friends' and family members' perfectionism on participants' aspirations, and the outcomes of prioritization of extrinsic aspirations. Having friends high in other-oriented perfectionism was significantly positively related to prioritization of extrinsic over intrinsic aspirations. Furthermore, living with friends amplified the effect. Last, prioritization of extrinsic aspirations at T1 was related to decreased subjective well-being and self-concordance for goals 3 months later. The study provides preliminary evidence for a relationship between friends' other-oriented perfectionism and students' orientation toward extrinsic aspirations, as well as negative prospective consequences of students' orientation to extrinsic aspirations. © 2015 Wiley Periodicals, Inc.

Awakening Aspirations of Primary School Students: Where Will Your Dreams Take You?

ERIC Educational Resources Information Center

Greenaway, Ruth; Terton, Uwe

2017-01-01

This article posits that when children are encouraged to aspire, they can become aware of a new world of choices and opportunities. Children should be supported to aspire in all areas of their lives. Of interest is children's capacity to aspire to attend tertiary education. Literature shows that children cannot aspire to attend higher education…

Dissociable Contributions within the Medial Temporal Lobe to Encoding of Object-Location Associations

ERIC Educational Resources Information Center

Sommer, Tobias; Rose, Michael; Glascher, Jan; Wolbers, Thomas; Buchel, Christian

2005-01-01

The crucial role of the medial temporal lobe (MTL) in episodic memory is well established. Although there is little doubt that its anatomical subregions--the hippocampus, peri-, entorhinal and parahippocampal cortex (PHC)--contribute differentially to mnemonic processes, their specific functions in episodic memory are under debate. Data from…

Limitation of the Cavitron technique by conifer pit aspiration.

PubMed

Beikircher, B; Ameglio, T; Cochard, H; Mayr, S

2010-07-01

The Cavitron technique facilitates time and material saving for vulnerability analysis. The use of rotors with small diameters leads to high water pressure gradients (DeltaP) across samples, which may cause pit aspiration in conifers. In this study, the effect of pit aspiration on Cavitron measurements was analysed and a modified 'conifer method' was tested which avoids critical (i.e. pit aspiration inducing) DeltaP. Four conifer species were used (Juniperus communis, Picea abies, Pinus sylvestris, and Larix decidua) for vulnerability analysis based on the standard Cavitron technique and the conifer method. In addition, DeltaP thresholds for pit aspiration were determined and water extraction curves were constructed. Vulnerability curves obtained with the standard method showed generally a less negative P for the induction of embolism than curves of the conifer method. Differences were species-specific with the smallest effects in Juniperus. Larix showed the most pronounced shifts in P(50) (pressure at 50% loss of conductivity) between the standard (-1.5 MPa) and the conifer (-3.5 MPa) methods. Pit aspiration occurred at the lowest DeltaP in Larix and at the highest in Juniperus. Accordingly, at a spinning velocity inducing P(50), DeltaP caused only a 4% loss of conductivity induced by pit aspiration in Juniperus, but about 60% in Larix. Water extraction curves were similar to vulnerability curves indicating that spinning itself did not affect pits. Conifer pit aspiration can have major influences on Cavitron measurements and lead to an overestimation of vulnerability thresholds when a small rotor is used. Thus, the conifer method presented here enables correct vulnerability analysis by avoiding artificial conductivity losses.

Post-obstructive pulmonary edema from aspirated nuts.

PubMed

Bashir, Ahsan; Ahmad, Sabina Qureshi; Silverman, Joshua; Concepcion, Emily; Lee, Haesoon

2017-01-01

Post-obstructive pulmonary edema is thought to occur from hemodynamic changes secondary to forced inspiration against the closed airway due to acute or chronic airway obstruction. We report a case of a 13 month-old boy who developed pulmonary edema from aspirated foreign body, nuts. He underwent emergency bronchoscopy to confirm the clinical diagnosis of aspirated nuts in the trachea and nuts were removed endoscopically. His trachea was then intubated and he was mechanically ventilated with oxygen. He developed florid pulmonary edema early in the course with tracheal obstruction and during endoscopic removal of nuts. After removal of obstruction he was ventilated mechanically and pulmonary edema cleared rapidly. Aspirated nuts obstructing trachea can induce obstructive pulmonary edema. Early recognition of foreign body obstruction based on clinical history and its removal resolved pulmonary edema.

Joint Pairing and Structured Mapping of Convolutional Brain Morphological Multiplexes for Early Dementia Diagnosis.

PubMed

Lisowska, Anna; Rekik, Islem

2018-06-21

Diagnosis of brain dementia, particularly early mild cognitive impairment (eMCI), is critical for early intervention to prevent the onset of Alzheimer's Disease (AD), where cognitive decline is severe and irreversible. There is a large body of machine-learning based research investigating how dementia alters brain connectivity, mainly using structural (derived from diffusion MRI) and functional (derived from resting-state functional MRI) brain connectomic data. However, how early dementia affects cortical brain connections in morphology remains largely unexplored. To fill this gap, we propose a joint morphological brain multiplexes pairing and mapping strategy for early MCI detection, where a brain multiplex not only encodes the similarity in morphology between pairs of brain regions, but also a pair of brain morphological networks. Experimental results confirm that the proposed framework outperforms in classification accuracy several state-of-the-art methods. More importantly, we unprecedentedly identified most discriminative brain morphological networks between eMCI and NC, which included the paired views derived from maximum principal curvature and the sulcal depth for the left hemisphere and sulcal depth and the average curvature for the right hemisphere. We also identified the most highly correlated morphological brain connections in our cohort, which included the (pericalcarine cortex, insula cortex) on the maximum principal curvature view, (entorhinal cortex, insula cortex) on the mean sulcal depth view, and (entorhinal cortex, pericalcarine cortex) on the mean average curvature view, for both hemispheres. These highly correlated morphological connections might serve as biomarkers for early MCI diagnosis.

Antibiotic Therapy in Comatose Mechanically Ventilated Patients Following Aspiration: Differentiating Pneumonia From Pneumonitis.

PubMed

Lascarrou, Jean Baptiste; Lissonde, Floriane; Le Thuaut, Aurélie; Bachoumas, Konstantinos; Colin, Gwenhael; Henry Lagarrigue, Matthieu; Vinatier, Isabelle; Fiancette, Maud; Lacherade, Jean Claude; Yehia, Aihem; Joret, Aurélie; Lebert, Christine; Bourdon, Sandra; Martin Lefèvre, Laurent; Reignier, Jean

2017-08-01

To determine the proportion of patients with documented bacterial aspiration pneumonia among comatose ICU patients with symptoms suggesting either bacterial aspiration pneumonia or non-bacterial aspiration pneumonitis. Prospective observational study. University-affiliated 30-bed ICU. Prospective cohort of 250 patients admitted to the ICU with coma (Glasgow Coma Scale score ≤ 8) and treated with invasive mechanical ventilation. None. The primary outcome was the proportion of patients with microbiologically documented bacterial aspiration pneumonia. Patients meeting predefined criteria for aspiration syndrome routinely underwent telescopic plugged catheter sampling during bronchoscopy before starting probabilistic antibiotic treatment. When cultures were negative, the antibiotic treatment was stopped. Of 250 included patients, 98 (39.2%) had aspiration syndrome, including 92 before mechanical ventilation discontinuation. Telescopic plugged catheter in these 92 patients showed bacterial aspiration pneumonia in 43 patients (46.7%). Among the remaining 49 patients, 16 continued to receive antibiotics, usually for infections other than pneumonia; of the 33 patients whose antibiotics were discontinued, only two subsequently showed signs of lung infection. In the six patients with aspiration syndrome after mechanical ventilation, and therefore without telescopic plugged catheter, antibiotic treatment was continued for 7 days. Mechanical ventilation duration, ICU length of stay, and mortality did not differ between the 43 patients with bacterial aspiration pneumonia and the 49 patients with non-bacterial aspiration pneumonitis. The 152 patients without aspiration syndrome did not receive antibiotics. Among comatose patients receiving mechanical ventilation, those without clinical, laboratory, or radiologic evidence of bacterial aspiration pneumonia did not require antibiotics. In those with suspected bacterial aspiration pneumonia, stopping empirical antibiotic therapy

Rural Aspirations, Rural Futures: From "Problem" to Possibility

ERIC Educational Resources Information Center

Tieken, Mara Casey; San Antonio, Donna M.

2016-01-01

Young people aspire, make choices, and develop within a particular place and historical context. Recently, federal and state governments, policy and research institutes, and advocacy organizations have shown a growing interest in the aspirations and transitions of rural youth--and, in particular, the role that schools play in shaping and…

Quality of canine spermatozoa retrieved by percutaneous epididymal sperm aspiration.

PubMed

Varesi, S; Vernocchi, V; Faustini, M; Luvoni, G C

2013-02-01

To investigate the feasibility of percutaneous epididymal sperm aspiration in dogs and whether it might provide a population of epididymal spermatozoa similar to the population that can be obtained by processing isolated epididymis caudae. Concentration and total sperm number, motility, morphology and acrosomal integrity of spermatozoa retrieved by percutaneous epididymal sperm aspiration, in vitro aspiration and mincing of the cauda of the epididymis were compared. Percutaneous epididymal sperm aspiration is a feasible procedure to retrieve a population of spermatozoa in dogs. Quality is similar to that of spermatozoa collected in vitro, although a wide variation amongst animals was observed. In case of ejaculation failure due to pathological conditions in dogs, the collection of spermatozoa from the cauda of the epididymis could be an option for providing gametes for assisted reproductive technologies. Percutaneous epididymal sperm aspiration can be used in dogs with compromised reproductive performance, in which orchiectomy cannot be performed for medical or owner reasons. Further studies aimed to investigate whether the percutaneous epididymal sperm aspiration technique might be feasible for repeated semen collection and to accurately evaluate side effects are required. © 2013 British Small Animal Veterinary Association.

Gender contentedness in aspirations to become engineers or medical doctors

NASA Astrophysics Data System (ADS)

Koul, Ravinder; Lerdpornkulrat, Thanita; Poondej, Chanut

2017-11-01

Medical doctor and engineer are highly esteemed STEM professions. This study investigates academic and motivational characteristics of a sample of high school students in Thailand who aspire to become medical doctors or engineers. We used logistic regression to compare maths performance, gender typicality, gender contentedness, and maths and physics self-concepts among students with aspirations for these two professions. We found that high levels of felt gender contentedness in men had positive association with aspirations for engineering irrespective of the levels of maths or physics self-concept. We found that high levels of felt gender contentedness combined with high levels of maths or physics self-concept in women had positive associations with aspirations to become a medical doctor. These findings are evidence that student views of self are associated with uneven gendered patterns in career aspirations and have implications for the potential for future participation.

The Role of Social Capital in Educational Aspirations of Rural Youth*

PubMed Central

Byun, Soo-yong; Meece, Judith L.; Irvin, Matthew J.; Hutchins, Bryan C.

2013-01-01

Drawing on a recent national survey of rural high school students, this study investigated the relationship between social capital and educational aspirations of rural youth. Results showed that various process features of family and school social capital were important to predict rural youth's educational aspirations beyond sociodemographic background. In particular, parents' and teachers' educational expectations for their child and student respectively were positively related to educational aspirations of rural youth. In addition, discussion with parents about college was positively related to educational aspirations of rural youth. On the other hand, there was little evidence to suggest that number of siblings and school proportions of students on free lunch and minority students are related to educational aspirations of rural youth, after controlling for the other variables. The authors highlight unique features of rural families, schools, and communities that may combine to explain the complexity of the role of social capital in shaping educational aspirations of rural youth. PMID:24039302

Chin tuck for prevention of aspiration: effectiveness and appropriate posture.

PubMed

Ra, Jong Yun; Hyun, Jung Keun; Ko, Kyung Rok; Lee, Seong Jae

2014-10-01

Chin tuck has been has been widely used to prevent aspiration in the patients with dysphagia. This study was performed to investigate the effectiveness and the degree of optimal neck flexion of chin tuck. Ninety-seven patients who showed aspiration in the videofluoroscopic swallow study (VFSS). Participants were grouped into the effective (patients who showed effect with chin tuck) and ineffective group (those who did not show effect with chin tuck). VFSS was performed in neutral and chin tuck position and findings were compared between the groups. Severity of aspiration was assessed by the point penetration-aspiration scale. Duration of dysphagic symptoms, history of tracheostomy, and other possible contributing factors were also compared. Neck flexion angle was measured to find appropriate posture in which aspiration was prevented with chin tuck. Aspiration was reduced or eliminated in only 19 patients (19.6 %) with chin tuck. Oral transit time, pharyngeal delayed time and pharyngeal transit time were significantly shortened in both groups (p < 0.05), but the difference between the groups was not significant. Female sex and absence of residue in pyriform sinus favored the effect of chin tuck (p < 0.05). At least 17.5° of neck flexion was required to achieve an effect with chin tuck. The effectiveness of chin tuck was less than anticipated. Patients without residue in pyriform sinus were more likely to benefit from chin tuck. Sufficient neck flexion was important in chin tuck to prevent aspiration.

Synaptic Phospholipid Signaling Modulates Axon Outgrowth via Glutamate-dependent Ca2+-mediated Molecular Pathways.

PubMed

Vogt, Johannes; Kirischuk, Sergei; Unichenko, Petr; Schlüter, Leslie; Pelosi, Assunta; Endle, Heiko; Yang, Jenq-Wei; Schmarowski, Nikolai; Cheng, Jin; Thalman, Carine; Strauss, Ulf; Prokudin, Alexey; Bharati, B Suman; Aoki, Junken; Chun, Jerold; Lutz, Beat; Luhmann, Heiko J; Nitsch, Robert

2017-01-01

Altered synaptic bioactive lipid signaling has been recently shown to augment neuronal excitation in the hippocampus of adult animals by activation of presynaptic LPA2-receptors leading to increased presynaptic glutamate release. Here, we show that this results in higher postsynaptic Ca2+ levels and in premature onset of spontaneous neuronal activity in the developing entorhinal cortex. Interestingly, increased synchronized neuronal activity led to reduced axon growth velocity of entorhinal neurons which project via the perforant path to the hippocampus. This was due to Ca2+-dependent molecular signaling to the axon affecting stabilization of the actin cytoskeleton. The spontaneous activity affected the entire entorhinal cortical network and thus led to reduced overall axon fiber numbers in the mature perforant path that is known to be important for specific memory functions. Our data show that precise regulation of early cortical activity by bioactive lipids is of critical importance for proper circuit formation. © The Author 2016. Published by Oxford University Press.

Aspirations langagieres: Negociation et apprentissage du francais (Language Aspirations: Negotiation and Learning French).

ERIC Educational Resources Information Center

Lepetit, Daniel; Cichocki, Wladyslaw

1990-01-01

A survey of 130 beginning French students at the University of Windsor (Canada) focused on their second language aspirations, expectations, and anticipated needs. Interpersonal relations appear to be the primary motivator, with travel and instrumental motivation secondary. (20 references) (Author/MSE)

Intergenerational Transmission of Educational Aspirations in Chinese Families: Identifying Mediators and Moderators.

PubMed

Wu, Nini; Hou, Yang; Wang, Qian; Yu, Chengfu

2018-06-01

Parents' educational aspirations for youth play an important role in shaping youth's own educational aspirations; however, little is known about how and in what context parents may transmit their aspirations to youth effectively. This is of particular interest and import to be examined in Chinese families, given Chinese cultural emphasis on educational achievement and Chinese youth's outstanding academic performance internationally. By integrating several key theories of motivation and parental socialization (i.e., the expectancy-value model of academic achievement, the two-step model of value transmission, the contextual model of parenting, and the self-determination theory), the current study investigated simultaneously the mediating roles of parental involvement in youth's learning and youth's perceptions of parental aspirations, as well as the moderating role of parental warmth in the intergenerational transmission process of educational aspirations in Chinese families. A two-wave longitudinal study spanning about half a year was conducted among 323 Chinese seventh graders (54% female; M age  = 13.25 years) and one of their parents (median educational attainment = completion of high school, median monthly income = USD 766-1226). It was found that parental educational aspirations for youth were related positively both indirectly through parental involvement and directly to youth's perceptions of parental aspirations, which in turn were associated positively with youth's own educational aspirations about half a year later. It was also found that parental educational aspirations for youth and youth's own educational aspirations were associated positively with each other only when youth reported experiencing high levels of parental warmth, but unrelated when youth reported experiencing low levels of parental warmth, whereas such moderating effects of parental warmth were absent on the links from parental aspirations to youth's perceptions of parental

Swiss Adolescents' Career Aspirations: Influence of Context, Age, and Career Adaptability

ERIC Educational Resources Information Center

Hirschi, Andreas

2010-01-01

This study investigated the content, realism, stability, and coherence of the career aspirations of 262 students in seventh grade in Switzerland (ages 13-15 years). The content analysis revealed that 82% of the participants named at least one realistic career aspiration, and aspirations showed clear resemblance to existing opportunities in the…

Practical Application of Aspiration as an Outcome Indicator in Extension Evaluation

ERIC Educational Resources Information Center

Jayaratne, K. S. U.

2010-01-01

Extension educators need simple and accurate evaluation tools for program evaluation. This article explains how to use aspiration as an outcome indicator in Extension evaluation and introduces a practical evaluation tool. Aspiration can be described as the readiness for change. By recording participants' levels of aspiration, we will be able to…

[Sequential monitoring of renal transplant with aspiration cytology].

PubMed

Manfro, R C; Gonçalves, L F; de Moura, L A

1998-01-01

To evaluate the utility of kidney aspiration cytology in the sequential monitorization of acute rejection in renal transplant patients. Thirty patients were submitted to 376 aspirations. The clinical diagnoses were independently established. The representativity of the samples reached 82.7%. The total corrected increment index and the number of immunoactivated cells were higher during acute rejection as compared to normal allograft function, acute tubular necrosis, and cyclosporine nephrotoxicity. The parameters to the diagnosis of acute rejection were sensitivity: 71.8%, specificity: 87.3%, positive predictive value: 50.9%, negative predictive value: 94.9% and accuracy 84.9%. The false positive results were mainly related to cytomegalovirus infection or to the administration of OKT3. In 10 out of 11 false negative results incipient immunoactivation was present alerting to the possibility of acute rejection. Kidney aspiration cytology is a useful tool for the sequential monitorization of acute rejection in renal transplant patients. The best results are reached when the results of aspiration cytology are analyzed with the clinical data.

Intrinsic aspirations and personal meaning across adulthood: conceptual interrelations and age/sex differences.

PubMed

Morgan, Jessica; Robinson, Oliver

2013-05-01

The present study examined adult age and sex differences in self-reported aspirations and personal meaning. Young, midlife, and older adults (N = 2,557) from the United Kingdom or United States completed an online survey of their aspiration striving, aspiration importance, and personal meaning (subscales of Purposeful Life, Exciting Life, Accomplished Life, Principled Life, Valued Life). Predictions were made in line with humanistic and gerontology theories, which suggest that sources of personal meaning consolidate across the life span toward intrinsically motivated pursuits. Findings supported these predictions, showing that although there was a tendency for aspirations to decline with age, the proportion of intrinsically motivated aspirations increased, as did total meaning and the interrelationship between meaning and intrinsic aspirations. There were also gender differences in personal meaning and aspirations, which suggested a more pronounced midlife dip in intrinsic and purposive goal striving for men, and a greater focus on intrinsic aspirations in women. Developmental and cohort interpretations of these findings and directions for further research are discussed.

The Role of Aspirations in Young Children's Emotional and Behavioural Problems

ERIC Educational Resources Information Center

Moulton, Vanessa; Flouri, Eirini; Joshi, Heather; Sullivan, Alice

2015-01-01

Using data from a large UK cohort (n = 11,656), we investigated the determinants of 7-year-old children's aspirations, and the role of these aspirations in emotional and behavioural problems, as reported by both parents and teachers. Aspirations were classified to reflect their occupational status, masculinity/femininity and intrinsic/extrinsic…

Young Children's Aspirations in Science: The unequivocal, the uncertain and the unthinkable

NASA Astrophysics Data System (ADS)

DeWitt, Jennifer; Osborne, Jonathan; Archer, Louise; Dillon, Justin; Willis, Beatrice; Wong, Billy

2013-04-01

Students' lack of interest in studying science and in science-related careers is a concern in the UK and worldwide. Yet there is limited data, particularly longitudinal, on the sources and development of science-related aspirations. In response, the ASPIRES (Science Aspirations and Career Choice: Age 10-14) longitudinal study is investigating the development of students' educational and occupational aspirations over time. In the first phase of the project, a questionnaire exploring science-related aspirations and interests was completed by over 9,000 primary school students across England. This survey allowed us to explore possible associations between attitudes and aspirations, links which have not been investigated in previous attitudinal studies of this scope. Overall, students expressed positive attitudes to science, reported positive parental attitudes to science and held very positive images of scientists. Multilevel modelling analyses revealed that aspirations in science were most strongly related to parental attitudes to science, attitudes to school science and self-concept in science, and are also associated with students' gender, ethnicity and cultural capital. However, the images students held of scientists were not as closely related to aspirations. These factors are discussed in more detail within the paper, alongside a consideration of possible school-related effects.

Aspiration and tetracycline sclerotherapy of hydroceles.

PubMed

Levine, L A; DeWolf, W C

1988-05-01

Aspiration and sclerotherapy of hydroceles have been considered an effective outpatient procedure. We report on our experience with modification of this procedure in the treatment of 28 hydroceles. A 10 per cent solution of tetracycline hydrochloride was used as the sclerosant. In this series the mean followup was 15 months and there was an over-all 93 per cent success rate. A single treatment was successful in 75 per cent of the hydroceles. Complications included a hematoma in 2 patients and epididymitis in 1. We consider aspiration and sclerotherapy of hydroceles to be a reasonable alternative to an operation.

Activation of Entorhinal Cortical Projections to the Dentate Gyrus Underlies Social Memory Retrieval.

PubMed

Leung, Celeste; Cao, Feng; Nguyen, Robin; Joshi, Krutika; Aqrabawi, Afif J; Xia, Shuting; Cortez, Miguel A; Snead, O Carter; Kim, Jun Chul; Jia, Zhengping

2018-05-22

Social interactions are essential to our mental health, and a deficit in social interactions is a hallmark characteristic of numerous brain disorders. Various subregions within the medial temporal lobe have been implicated in social memory, but the underlying mechanisms that tune these neural circuits remain unclear. Here, we demonstrate that optical activation of excitatory entorhinal cortical perforant projections to the dentate gyrus (EC-DG) is necessary and sufficient for social memory retrieval. We further show that inducible disruption of p21-activated kinase (PAK) signaling, a key pathway important for cytoskeletal reorganization, in the EC-DG circuit leads to impairments in synaptic function and social recognition memory, and, importantly, optogenetic activation of the EC-DG terminals reverses the social memory deficits in the transgenic mice. These results provide compelling evidence that activation of the EC-DG pathway underlies social recognition memory recall and that PAK signaling may play a critical role in modulating this process. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Minimally invasive image-guided keyhole aspiration of cerebral abscesses.

PubMed

Meng, Xiang-Hui; Feng, Shi-Yu; Chen, Xiao-Lei; Li, Chong; Zhang, Jiashu; Zhou, Tao; Jiang, Jinli; Wang, Fuyu; Ma, Xiaodong; Bu, Bo; Yu, Xin-Guang

2015-01-01

Despite the low incidence of brain abscesses in Western nations (1-2%), the incidence in developing countries is as high as 8%. We evaluate a minimally invasive image-guided keyhole aspiration of cerebral abscesses and compare it with a series of cases treated with surgical excision. 23 patients (20 male and 3 female, aged 7-67 years) underwent image-guided burr hole aspiration of single or multiple cerebral abscesses. Patient characteristics, perioperative, and postoperative data were analyzed and compared with a second group of 22 patients (14 male and 8 female, aged 12-72) treated for cerebral abscesses with open surgical excision. In all cases, the surgical procedure was performed successfully without complication. 8 of the 23 aspiration cases were performed with the aid of iMRI. A comparison of patient demographics, duration of hospital stay, duration of antibiotic therapy, postoperative neurological recovery time, intraoperative blood loss, operative duration, length of incision, postoperative fever, repeat surgery, and mortality was performed between the aspiration and excision groups. Intraoperative blood loss, operative duration, length of incision, and postoperative fever were all significantly reduced in the aspiration group. Though, duration of hospital stay and antibiotic therapy and postoperative neurological recovery time were all increased in the aspiration group, and statistical significance was observed in all except the duration of hospital stay. This technique is a feasible and comparable minimally invasive alternative to open surgical excision and may provide reduced intraoperative blood loss, shortened operative duration, improved cosmetic outcomes, and a lessened incidence of postoperative fever.

Sociological Theory and Youth Aspiration Research: A Critical Overview.

ERIC Educational Resources Information Center

Picou, J. Steven; Wells, Richard H.

Reviewing sociological theories relative to youth aspiration research, the following thesis was presented: "pre-path analysis aspiration research was characterized by a person-centered, middle-range functionalist approach which eventually shifted to a person-centered, functionalist-system approach with the introduction of the path model…

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule

PubMed Central

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases. PMID:26600772

Capsule Endoscope Aspiration after Repeated Attempts for Ingesting a Patency Capsule.

PubMed

Mannami, Tomohiko; Ikeda, Genyo; Seno, Satoru; Sonobe, Hiroshi; Fujiwara, Nobukiyo; Komoda, Minori; Edahiro, Satoru; Ohtawa, Yasuyuki; Fujimoto, Yoshimi; Sato, Naohiro; Kambara, Takeshi; Waku, Toshihiko

2015-01-01

Capsule endoscope aspiration into the respiratory tract is a rare complication of capsule endoscopy. Despite the potential seriousness of this complication, no accepted methods exist to accurately predict and therefore prevent it. We describe the case of an 85-year-old male who presented for evaluation of iron deficiency anemia. He complained of dysphagia while ingesting a patency capsule, with several attempts over a period of 5 min before he was successful. Five days later, he underwent capsule endoscopy, where he experienced similar symptoms in swallowing the capsule. The rest of the examination proceeded uneventfully. On reviewing the captured images, the capsule endoscope was revealed to be aspirated, remaining in the respiratory tract for approximately 220 s before images of the esophagus and stomach appeared. To our knowledge, this is the first documented case of a patient who experienced capsule endoscope aspiration after ingestion of a patency capsule. This case suggests that repeated attempts required for ingesting the patency capsule can predict capsule endoscope aspiration. We presume that paying sufficient attention to the symptoms of a patient who ingests a patency capsule could help us prevent serious complications such as aspiration of the capsule endoscope. In addition, this experience implies the potential risk for ingesting the patency capsule. We must be aware that the patency capsule could also be aspirated and there may be more unrecognized aspiration cases.

21 CFR 886.4150 - Vitreous aspiration and cutting instrument.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Vitreous aspiration and cutting instrument. 886.4150 Section 886.4150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... cutting instrument. (a) Identification. A vitreous aspiration and cutting instrument is an electrically...

21 CFR 886.4150 - Vitreous aspiration and cutting instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vitreous aspiration and cutting instrument. 886.4150 Section 886.4150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... cutting instrument. (a) Identification. A vitreous aspiration and cutting instrument is an electrically...

Age-related Changes in Lateral Entorhinal and CA3 Neuron Allocation Predict Poor Performance on Object Discrimination

PubMed Central

Maurer, Andrew P.; Johnson, Sarah A.; Hernandez, Abbi R.; Reasor, Jordan; Cossio, Daniela M.; Fertal, Kaeli E.; Mizell, Jack M.; Lubke, Katelyn N.; Clark, Benjamin J.; Burke, Sara N.

2017-01-01

Age-related memory deficits correlate with dysfunction in the CA3 subregion of the hippocampus, which includes both hyperactivity and overly rigid activity patterns. While changes in intrinsic membrane currents and interneuron alterations are involved in this process, it is not known whether alterations in afferent input to CA3 also contribute. Neurons in layer II of the lateral entorhinal cortex (LEC) project directly to CA3 through the perforant path, but no data are available regarding the effects of advanced age on LEC activity and whether these activity patterns update in response to environmental change. Furthermore, it is not known the extent to which age-related deficits in sensory discrimination relate to the inability of aged CA3 neurons to update in response to new environments. Young and aged rats were pre-characterized on a LEGO© object discrimination task, comparable to behavioral tests in humans in which CA3 hyperactivity has been linked to impairments. The cellular compartment analysis of temporal activity with fluorescence in situ hybridization for the immediate-early gene Arc was then used to identify the principal cell populations that were active during two distinct epochs of random foraging in different environments. This approach enabled the extent to which rats could discriminate two similar objects to be related to the ability of CA3 neurons to update across different environments. In both young and aged rats, there were animals that performed poorly on the LEGO object discrimination task. In the aged rats only, however, the poor performers had a higher percent of CA3 neurons that were active during random foraging in a novel environment, but this is not related to the ability of CA3 neurons to remap when the environment changed. Afferent neurons to CA3 in LEC, as identified with the retrograde tracer choleratoxin B (CTB), also showed a higher percentage of cells that were positive for Arc mRNA in aged poor performing rats. This suggests

Guided percutaneous fine-needle aspiration biopsy of the liver

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

Ho, C.S.; McLoughlin, M.J.; Tao, L.C.

1981-04-01

Forty patients with suspected malignant disease of the liver underwent percutaneous fine-needle aspiration biopsy with radioisotope scintigraphic and fluoroscopic guidance. The needle was aimed at focal defects identified on the liver scan and several passes were made. When the scan was diffusely abnormal, the liver was widely sampled with multiple passes. Thirty patients were eventually considered to have malignant disease and aspiration biopsy was positive in 28 (93%) of these patients, including 25 of 26 with liver metastases (96%). There were two false-positive results and one minor complication. In 24 patients, conventional wide-bore needle biopsy was also performed. In thismore » group, 16 patients had a final diagnosis of hepatic malignancy. Aspiration biopsies were positive in 14 of these (87%) and conventional needle biopsies were positive in four (25%). Guided percutaneous fine-needle aspiration biopsy is recommended for pathologic diagnosis of hepatic malignancy because of its simplicity, high yield, and reasonable safety.« less

Infrared Thermal Imaging During Ultrasonic Aspiration of Bone

NASA Astrophysics Data System (ADS)

Cotter, D. J.; Woodworth, G.; Gupta, S. V.; Manandhar, P.; Schwartz, T. H.

Ultrasonic surgical aspirator tips target removal of bone in approaches to tumors or aneurysms. Low profile angled tips provide increased visualization and safety in many high risk surgical situations that commonly were approached using a high speed rotary drill. Utilization of the ultrasonic aspirator for bone removal raised questions about relative amount of local and transmitted heat energy. In the sphenoid wing of a cadaver section, ultrasonic bone aspiration yielded lower thermal rise in precision bone removal than rotary mechanical drills, with maximum temperature of 31 °C versus 69 °C for fluted and 79 °C for diamond drill bits. Mean ultrasonic fragmentation power was about 8 Watts. Statistical studies using tenacious porcine cranium yielded mean power levels of about 4.5 Watts to 11 Watts and mean temperature of less than 41.1 °C. Excessively loading the tip yielded momentary higher power; however, mean thermal rise was less than 8 °C with bone removal starting at near body temperature of about 37 °C. Precision bone removal and thermal management were possible with conditions tested for ultrasonic bone aspiration.

Variation in the Diagnosis of Aspiration Pneumonia and Association with Hospital Pneumonia Outcomes.

PubMed

Lindenauer, Peter K; Strait, Kelly M; Grady, Jacqueline N; Ngo, Chi K; Parisi, Madeline L; Metersky, Mark; Ross, Joseph S; Bernheim, Susannah M; Dorsey, Karen

2018-05-01

National efforts to compare hospital outcomes for patients with pneumonia may be biased by hospital differences in diagnosis and coding of aspiration pneumonia, a condition that has traditionally been excluded from pneumonia outcome measures. To evaluate the rationale and impact of including patients with aspiration pneumonia in hospital mortality and readmission measures. Using Medicare fee-for-service claims for patients 65 years and older from July 2012 to June 2015, we characterized the proportion of hospitals' patients with pneumonia diagnosed with aspiration pneumonia, calculated hospital-specific risk-standardized rates of 30-day mortality and readmission for patients with pneumonia, analyzed the association between aspiration pneumonia coding frequency and these rates, and recalculated these rates including patients with aspiration pneumonia. A total of 1,101,892 patients from 4,263 hospitals were included in the mortality measure analysis, including 192,814 with aspiration pneumonia. The median proportion of hospitals' patients with pneumonia diagnosed with aspiration pneumonia was 13.6% (10th-90th percentile, 4.2-26%). Hospitals with a higher proportion of patients with aspiration pneumonia had lower risk-standardized mortality rates in the traditional pneumonia measure (12.0% in the lowest coding and 11.0% in the highest coding quintiles) and were far more likely to be categorized as performing better than the national mortality rate; expanding the measure to include patients with aspiration pneumonia attenuated the association between aspiration pneumonia coding rate and hospital mortality. These findings were less pronounced for hospital readmission rates. Expanding the pneumonia cohorts to include patients with a principal diagnosis of aspiration pneumonia can overcome bias related to variation in hospital coding.

[Clinical characteristics of lipid aspiration pneumonia in 16 children].

PubMed

Ge, Lisha; Chen, Sihu; Lin, Miaomiao; Xia, Xiaojiao; Jin, Yimei; He, Shijun

2014-03-01

To investigate clinical characteristics and changes of pulmonary imaging of mineral oil aspiration pneumonia in children. The clinical features, CT findings, and effects of corticosteroid therapy were analyzed in 16 children with mineral oil aspiration pneumonia, who were hospitalized in our hospital from January 2003 to July 2013. All patients with mineral oil aspiration pneumonia had a history of mineral oil administration.Four patients had no clinical manifestations. Ten cases presented fever, and 8 of the 10 patients had fever in 4-8 h after taking mineral oil, and the temperature was between 39-40 °C. There were wheezing in 2 cases, shortness of breath in 6 cases, cyanosis in 1 case, dyspnea in 3 cases, and moaning in 2 cases, chest pain in 1 case, headache and abnormal EEG in 1 case.Six patients had rales in lungs. Peripheral blood white cells increased in 10 cases, and C- reactive protein elevated in 7 patients. Chest CT examination showed abnormal findings in 6 children, and the earliest CT was performed within 2 h after the accident. The rest 10 children got chest X-ray, and 9 of 10 children had abnormal findings. The earliest X-ray was done within 3 h after the accident. And the remaining 1 of 10 children showed no significant changes in the first chest X-ray 2-3 h after the accident until 3 days. All of the patients received corticosteroid and antibiotic treatments, 4 cases underwent bronchoalveolar lavage, 3 patients were given albumin, 6 cases received intravenous immunoglobulin. Three cases delayed in treatment with hormone because of misdiagnosis, and 2 of them had clearly secondary infections. Twelve patients recovered completely from oil aspiration pneumonia after 8 days to 5.5 months. Oil aspiration pneumonia in children occurs in almost all cases after mineral oil aspiration. Pulmonary opacities can be found by chest CT in most patients within 24 hours after mineral oil aspiration. Corticosteroids therapy was effective for patients with

Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer

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

Adamov, Alexey; Viidanoja, Jyrki; Kaerpaenoja, Esko

2007-04-15

This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate.

Decreased Cough Sensitivity and Aspiration in Parkinson Disease

PubMed Central

Brandimore, Alexandra E.; Okun, Michael S.; Davenport, Paul W.; Hegland, Karen W.

2014-01-01

BACKGROUND: Aspiration pneumonia is a leading cause of death in people with Parkinson disease (PD). The pathogenesis of these infections is largely attributed to the presence of dysphagia with silent aspiration or aspiration without an appropriate cough response. The goal of this study was to test reflex cough thresholds and associated urge-to-cough (UTC) ratings in participants with PD with and without dysphagia. METHODS: Twenty participants with PD were recruited for this study. They completed a capsaicin challenge with three randomized blocks of 0, 50, 100, and 200 μM capsaicin and rated their UTC by modified Borg scale. The concentration of capsaicin that elicited a two-cough response, total number of coughs, and sensitivity of the participant to the cough stimulus (UTC) were measured. The dysphagia severity of participants with PD was identified with the penetration-aspiration scale. RESULTS: Most participants with PD did not have a consistent two-cough response to 200 μM capsaicin. UTC ratings and total number of coughs produced at 200 μM capsaicin were significantly influenced by dysphagia severity but not by general PD severity, age, or disease duration. Increasing levels of dysphagia severity resulted in significantly blunted cough sensitivity (UTC). CONCLUSIONS: UTC ratings may be important in understanding the mechanism underlying morbidity related to aspiration pneumonia in people with PD and dysphagia. Further understanding of decreased UTC in people with PD and dysphagia will be essential for the development of strategies and treatments to address airway protection deficits in this population. PMID:24968148

The Path Taken: Consequences of Attaining Intrinsic and Extrinsic Aspirations in Post-College Life

PubMed Central

Niemiec, Christopher P.; Ryan, Richard M.; Deci, Edward L.

2009-01-01

Life goals, or aspirations, organize and direct behavior over extended periods of time. The present study, guided by self-determination theory, examined the consequences of pursuing and attaining aspirations over a one-year period in a post-college sample. Results indicated that placing importance on either intrinsic or extrinsic aspirations related positively to attainment of those goals. Yet, whereas attainment of intrinsic aspirations related positively to psychological health, attainment of extrinsic aspirations did not; indeed, attainment of extrinsic aspirations related positively to indicators of ill-being. Also as predicted, the association between change in attainment of intrinsic aspirations and change in psychological health was mediated by change in the satisfaction of the basic psychological needs for autonomy, competence, and relatedness. Discussion focuses on the idea that not all goal attainment is beneficial; rather, attainment of aspirations with different contents relates differentially to psychological health. PMID:20161160

The Path Taken: Consequences of Attaining Intrinsic and Extrinsic Aspirations in Post-College Life.

PubMed

Niemiec, Christopher P; Ryan, Richard M; Deci, Edward L

2009-06-01

Life goals, or aspirations, organize and direct behavior over extended periods of time. The present study, guided by self-determination theory, examined the consequences of pursuing and attaining aspirations over a one-year period in a post-college sample. Results indicated that placing importance on either intrinsic or extrinsic aspirations related positively to attainment of those goals. Yet, whereas attainment of intrinsic aspirations related positively to psychological health, attainment of extrinsic aspirations did not; indeed, attainment of extrinsic aspirations related positively to indicators of ill-being. Also as predicted, the association between change in attainment of intrinsic aspirations and change in psychological health was mediated by change in the satisfaction of the basic psychological needs for autonomy, competence, and relatedness. Discussion focuses on the idea that not all goal attainment is beneficial; rather, attainment of aspirations with different contents relates differentially to psychological health.

Extramedullary plasmacytoma. Fine needle aspiration findings.

PubMed

Kumar, P V; Owji, S M; Talei, A R; Malekhusseini, S A

1997-01-01

To determine the role of fine needle aspiration cytology in the diagnosis of extramedullary plasmacytoma. The study group consisted of 13 patients with palpable masses at various sites. The tumors were aspirated for cytologic study. The smears revealed groups of mature and immature plasma cells at various stages of maturation. Mature plasma cells showed an eccentric nucleus and abundant, deep, basophilic cytoplasm with a paranuclear halo. Plasmablasts (immature plasma cells) showed a prominent, eccentric nucleus with single, large nucleolus and abundant, deep, basophilic cytoplasm with no paranuclear halo. Binucleate and multinucleate forms were also seen quite often. The tumors were excised, and the histologic sections confirmed the cytologic diagnosis. All the patients received radiotherapy. One patient (18 years old) developed recurrence and died due to extensive infiltration into the maxilla and mandible. Two patients (57 and 62 years) developed multiple myeloma one to two years after the excision of tumors, and both died two to three months later. The remaining 10 patients were alive and well at this writing. The smears from all 13 patients were diagnosed as extramedullary plasmacytomas by fine needle aspiration cytology.

Life Aspirations, Values and Moral Foundations in Mongolian Youth

ERIC Educational Resources Information Center

Bespalov, Alexander; Prudnikova, Marina; Nyamdorj, Bavuu; Vlasov, Mikhail

2017-01-01

Life aspirations have aroused much interest in youth studies. Yet, their psychological correlates remain unclear, especially in countries outside the US. The aim of this study was to explore associations among aspirations, values and moral foundations in 157 Mongolian youth, through questionnaires used widely around the world. Correlational and…

Aspiration of capsule endoscope and successful bronchoscopic extraction.

PubMed

Girdhar, Ankur; Usman, Faisal; Bajwa, Abubakr

2012-10-01

Capsule endoscopy is a novel tool for the diagnosis of small intestinal disorders. Recently, a new complication of the procedure in the form of the capsule's aspiration into the lungs has been reported. The aspiration of capsule endoscope can lead to a variety of complications including respiratory failure. A low threshold to suspect this complication and urgent bronchoscopic extraction in appropriate patients can prevent serious sequelae.

Parental Influence on Mainland Chinese Children's Career Aspirations: Child and Parental Perspectives

ERIC Educational Resources Information Center

Liu, Jianwei; McMahon, Mary; Watson, Mark

2015-01-01

Career aspirations developed in childhood may impact on future career development in adolescence and adulthood. Family is an important context in which children develop their career aspirations. This study examined how parents influence children's career aspirations in mainland China from both the parents' and children's perspectives. Eight…

Correlation between laryngeal sensitivity and penetration/aspiration after stroke.

PubMed

Onofri, Suely Mayumi Motonaga; Cola, Paula Cristina; Berti, Larissa Cristina; da Silva, Roberta Gonçalves; Dantas, Roberto Oliveira

2014-04-01

Stroke is the most common neurological disease in adults that is associated with deglutition disorders. The presence of laryngeal sensitivity is very important in developing safe swallowing without risk of pulmonary complications. The aim of this study was to correlate laryngeal sensitivity with laryngeal penetration and tracheal aspiration after swallows of three food consistencies (puree, thickened liquid, and liquid) in poststroke individuals in the late phase. A cross-sectional clinical study was performed with 91 post-ischemic stroke individuals, with oropharyngeal dysphagia, who were in rehabilitation center treatment from 2009 to 2011. They had a mean age of 68.1 years and average time since injury was 22.6 months; 39 had injury to the right hemisphere and 52 had injury to the left hemisphere. All underwent fiberoptic endoscopic evaluation of swallowing and evaluation of laryngeal sensitivity by touching the tip of the endoscope to the arytenoids and aryepiglottic folds. The linear correlation coefficient of Spearman was applied to evaluate the correlation between laryngeal penetration and tracheal aspiration and the presence/absence of laryngeal sensitivity. There was a negative correlation between the observation of penetration and tracheal aspiration and laryngeal sensitivity, with all bolus consistencies (p < 0.001 for aspiration and p ≤ 0.01 for penetration). The absence of laryngeal sensitivity determines the more frequent findings of penetration and tracheal aspiration. This sensory stimulus in the mucosa of the pharynx and larynx is an essential element for safe swallowing and its deficiency associated with altered motor activity can cause laryngeal penetration and aspiration in poststroke individuals regardless of food consistency.

Olfactory memory and maternal behaviour-induced changes in c-fos and zif/268 mRNA expression in the sheep brain.

PubMed

Da Costa, A P; Broad, K D; Kendrick, K M

1997-06-01

In sheep maternal behaviour and the formation of the selective olfactory, ewe/lamb bond are induced by feedback to the brain from stimulation of the vagina and cervix during parturition. In the present study, we have used in situ hybridization histochemistry to quantify changes in cellular expression of two immediately-early genes, c-fos and zif/268, in order to identify activated brain regions during the induction of maternal behaviour and olfactory bonding as well as regions where plastic changes are occurring during with the formation of the olfactory memory associated with bonding. Three different treatment groups were used. One group gave birth normally, became maternal and were allowed to interact with their lambs for 30 min. A second group received exogenous treatment with oestradiol and progesterone to induce lactation and then received a 5-min period of artificial stimulation of the vagina and cervix (VCS) which reliably induces maternal behaviour but could not interact with lambs. A final control group received exogenous hormone treatment but no VCS or interaction with lambs. Compared to the control group, post-partum animals and animals that had received VCS showed increased c-fos expression in a number of cortical regions (cingulate, entorhinal and somatosensory), the mediodorsal thalamic nucleus and the lateral habenula, the limbic system (bed nucleus of the stria terminalis, lateral septum, medial arnygdala, dentate gyrus and the CA3 region of the hippocampus) and the hypothalamus (medial preoptic area, mediobasal hypothalamus, paraventricular nucleus, supraoptic nucleus and periventricular complex). The group that gave birth and had contact with their lambs for 30 min had significantly enhanced c-fos mRNA expression in the cingulate cortex compared to those receiving VCS and additionally showed significantly increased c-fos mRNA expression in olfactory processing regions (olfactory bulb, piriform cortex and orbitofrontal cortex). Expression of zif

Ear Scaffold Reconstruction Using Ultrasonic Aspirator for Cauliflower Ear.

PubMed

Hao, Scarlett; Angster, Kristen; Hubbard, Fleesie; Greywoode, Jewel; Vakharia, Kalpesh T

2018-04-01

Untreated auricular hematomas from ear trauma can result in an ear deformation known as cauliflower ear, secondary to fibrosis and new cartilage overgrowth. Cauliflower ear reconstruction has traditionally utilized tools such as a drill or a scalpel in order to improve auricular cosmesis. We present a case report utilizing an ultrasonic aspirator to recontour the fibrosed cartilage of a cauliflower ear. The ultrasonic aspirator has advantages over traditional tools in its ability to provide finely controlled bone removal without damage to surrounding soft tissue. The patient in this case report underwent multistage reconstruction using the ultrasonic aspirator with excellent cosmetic result and patient satisfaction.

Students' Aspirations, Expectations and School Achievement: What Really Matters?

ERIC Educational Resources Information Center

Khattab, Nabil

2015-01-01

Using the Longitudinal Study of Young People in England (LSYPE), this study examines how different combinations of aspirations, expectations and school achievement can influence students' future educational behaviour (applying to university at the age of 17-18). The study shows that students with either high aspirations or high expectations have…

Occupational Aspirations of State FFA Contest and Award Winners.

ERIC Educational Resources Information Center

Bowen, Blannie E.; Doerfert, David L.

1989-01-01

A study explored the occupational aspirations of 300 (of 503) students with high levels of participation in Future Farmers of America's (FFA) Computers in Agriculture (CIA), Proficiency Award (PA), and Prepared and Extemporaneous Speaking (PES) contests. CIA and PES winners aspired to professional occupations more than PA winners. PES winners…

Advances in the behavioural testing and network imaging of rodent recognition memory

PubMed Central

Kinnavane, Lisa; Albasser, Mathieu M.; Aggleton, John P.

2015-01-01

Research into object recognition memory has been galvanised by the introduction of spontaneous preference tests for rodents. The standard task, however, contains a number of inherent shortcomings that reduce its power. Particular issues include the problem that individual trials are time consuming, so limiting the total number of trials in any condition. In addition, the spontaneous nature of the behaviour and the variability between test objects add unwanted noise. To combat these issues, the ‘bow-tie maze’ was introduced. Although still based on the spontaneous preference of novel over familiar stimuli, the ability to give multiple trials within a session without handling the rodents, as well as using the same objects as both novel and familiar samples on different trials, overcomes key limitations in the standard task. Giving multiple trials within a single session also creates new opportunities for functional imaging of object recognition memory. A series of studies are described that examine the expression of the immediate-early gene, c-fos. Object recognition memory is associated with increases in perirhinal cortex and area Te2 c-fos activity. When rats explore novel objects the pathway from the perirhinal cortex to lateral entorhinal cortex, and then to the dentate gyrus and CA3, is engaged. In contrast, when familiar objects are explored the pathway from the perirhinal cortex to lateral entorhinal cortex, and then to CA1, takes precedence. The switch to the perforant pathway (novel stimuli) from the temporoammonic pathway (familiar stimuli) may assist the enhanced associative learning promoted by novel stimuli. PMID:25106740

Automated Volumetry and Regional Thickness Analysis of Hippocampal Subfields and Medial Temporal Cortical Structures in Mild Cognitive Impairment

PubMed Central

Yushkevich, Paul A.; Pluta, John B.; Wang, Hongzhi; Xie, Long; Ding, Song-Lin; Gertje, E. C.; Mancuso, Lauren; Kliot, Daria; Das, Sandhitsu R.; Wolk, David A.

2014-01-01

We evaluate a fully automatic technique for labeling hippocampal subfields and cortical subregions in the medial temporal lobe (MTL) in in vivo 3 Tesla MRI. The method performs segmentation on a T2-weighted MRI scan with 0.4 × 0.4 × 2.0 mm3 resolution, partial brain coverage, and oblique orientation. Hippocampal subfields, entorhinal cortex, and perirhinal cortex are labeled using a pipeline that combines multi-atlas label fusion and learning-based error correction. In contrast to earlier work on automatic subfield segmentation in T2-weighted MRI (Yushkevich et al., 2010), our approach requires no manual initialization, labels hippocampal subfields over a greater anterior-posterior extent, and labels the perirhinal cortex, which is further subdivided into Brodmann areas 35 and 36. The accuracy of the automatic segmentation relative to manual segmentation is measured using cross-validation in 29 subjects from a study of amnestic Mild Cognitive Impairment (aMCI), and is highest for the dentate gyrus (Dice coefficient is 0.823), CA1 (0.803), perirhinal cortex (0.797) and entorhinal cortex (0.786) labels. A larger cohort of 83 subjects is used to examine the effects of aMCI in the hippocampal region using both subfield volume and regional subfield thickness maps. Most significant differences between aMCI and healthy aging are observed bilaterally in the CA1 subfield and in the left Brodmann area 35. Thickness analysis results are consistent with volumetry, but provide additional regional specificity and suggest non-uniformity in the effects of aMCI on hippocampal subfields and MTL cortical subregions. PMID:25181316

Prefrontal-Hippocampal Pathways Underlying Inhibitory Control Over Memory

PubMed Central

Anderson, Michael C.; Bunce, Jamie G.; Barbas, Helen

2016-01-01

A key function of the prefrontal cortex is to support inhibitory control over behavior. It is widely believed that this function extends to stopping cognitive processes as well. Consistent with this, mounting evidence establishes the role of the right lateral prefrontal cortex in a clear case of cognitive control: retrieval suppression. Retrieval suppression refers to the ability to intentionally stop the retrieval process that arises when a reminder to a memory appears. Functional imaging data indicates that retrieval suppression involves top-down modulation of hippocampal activity by the dorsolateral prefrontal cortex, but the anatomical pathways supporting this inhibitory modulation remain unclear. Here we bridge this gap by integrating key findings about retrieval suppression observed through functional imaging with a detailed consideration of relevant anatomical pathways observed in non-human primates. Focusing selectively on the potential role of the anterior cingulate cortex, we develop two hypotheses about the pathways mediating interactions between lateral prefrontal cortex and the medial temporal lobes during suppression, and their cellular targets: the entorhinal gating hypothesis, and thalamo-hippocampal modulation via the nucleus reuniens. We hypothesize that whereas entorhinal gating is well situated to stop retrieval proactively, thalamo-hippocampal modulation may interrupt an ongoing act of retrieval reactively. Isolating the pathways that underlie retrieval suppression holds the potential to advance our understanding of a range of psychiatric disorders characterized by persistent intrusive thoughts. More broadly, an anatomical account of retrieval suppression would provide a key model system for understanding inhibitory control over cognition. PMID:26642918

Aspiration pneumonia induces muscle atrophy in the respiratory, skeletal, and swallowing systems.

PubMed

Komatsu, Riyo; Okazaki, Tatsuma; Ebihara, Satoru; Kobayashi, Makoto; Tsukita, Yoko; Nihei, Mayumi; Sugiura, Hisatoshi; Niu, Kaijun; Ebihara, Takae; Ichinose, Masakazu

2018-05-22

Repetition of the onset of aspiration pneumonia in aged patients is common and causes chronic inflammation. The inflammation induces proinflammatory cytokine production and atrophy in the muscles. The proinflammatory cytokines induce muscle proteolysis by activating calpains and caspase-3, followed by further degradation by the ubiquitin-proteasome system. Autophagy is another pathway of muscle atrophy. However, little is known about the relationship between aspiration pneumonia and muscle. For swallowing muscles, it is not clear whether they produce cytokines. The main objective of this study was to determine whether aspiration pneumonia induces muscle atrophy in the respiratory (the diaphragm), skeletal (the tibialis anterior, TA), and swallowing (the tongue) systems, and their possible mechanisms. We employed a mouse aspiration pneumonia model and computed tomography (CT) scans of aged pneumonia patients. To induce aspiration pneumonia, mice were inoculated with low dose pepsin and lipopolysaccharide solution intra-nasally 5 days a week. The diaphragm, TA, and tongue were isolated, and total RNA, proteins, and frozen sections were stored. Quantitative real-time polymerase chain reaction determined the expression levels of proinflammatory cytokines, muscle E3 ubiquitin ligases, and autophagy related genes. Western blot analysis determined the activation of the muscle proteolysis pathway. Frozen sections determined the presence of muscle atrophy. CT scans were used to evaluate the muscle atrophy in aged aspiration pneumonia patients. The aspiration challenge enhanced the expression levels of proinflammatory cytokines in the diaphragm, TA, and tongue. Among muscle proteolysis pathways, the aspiration challenge activated caspase-3 in all the three muscles examined, whereas calpains were activated in the diaphragm and the TA but not in the tongue. Activation of the ubiquitin-proteasome system was detected in all the three muscles examined. The aspiration challenge

Apolipoprotein E epsilon4 does not modulate amyloid-β-associated neurodegeneration in preclinical Alzheimer disease.

PubMed

Desikan, R S; McEvoy, L K; Holland, D; Thompson, W K; Brewer, J B; Aisen, P S; Andreassen, O A; Hyman, B T; Sperling, R A; Dale, A M

2013-03-01

Among cognitively healthy older individuals, the relationship among the 2 hallmark proteins of AD (Aβ and τ APOE ε4) and neurodegeneration is not well-understood. Here, we investigated the relationship between Aβ, p-τ, and APOE ε4 on longitudinal brain atrophy in preclinical AD. We examined 107 cognitively healthy older adults who underwent longitudinal MR imaging and baseline lumbar puncture. Within the same linear mixed-effects model, we concurrently investigated main and interactive effects between the APOE ε4 genotype and CSF Aβ(1-42), CSF p-τ and CSF Aβ(1-42), and the APOE ε4 genotype and CSF p-τ on entorhinal cortex atrophy rate. We also examined the relationship of APOE ε4, CSF p-τ, and CSF Aβ(1-42) on the atrophy rate of other AD-vulnerable neuroanatomic regions. The full model with main and interactive effects demonstrated a significant interaction only between CSF p-τ and CSF Aβ(1-42) on entorhinal cortex atrophy rate, indicating elevated atrophy with time in individuals with increased CSF p-τ and decreased CSF Aβ(1-42). The APOE ε4 genotype was significantly and specifically associated with CSF Aβ(1-42). However, the interaction between the APOE ε4 genotype and either CSF Aβ(1-42) or CSF p-τ on entorhinal cortex atrophy rate was not significant. We found similar results in other AD-vulnerable regions. On the basis of our findings and building on prior experimental evidence, we propose a model of the pathogenic cascade underlying preclinical AD in which APOE ε4 primarily influences the pathology of Alzheimer disease via Aβ-related mechanisms, and in turn, Aβ-associated neurodegeneration occurs only in the presence of p-τ.

[Study of the predictive value of detection tests for silent aspirations].

PubMed

Woisard, V; Réhault, E; Brouard, C; Fichaux-Bourin, P; Puech, M; Grand, S

2009-01-01

Screening for aspiration in patients with swallowing disorders is important in preventing complications. The tests used in this regard are insufficient due to silent aspiration relating to abnormal protective reflexes in many patients with swallowing problems. The aim of this study is to determine the predictive values of simple tests in screening for silent aspiration. The reference test used was videofluoroscopic examination on swallowing. In the presence of aspiration (FR+) the presence (ME+) or not (ME-) of a cough of throat clearing was noted. The tests being studied were a nasal test with isotonic saline and swallowing according to a set time. For screening for aspiration the presence of a "wet voice" was considered to be a sign of reduced protective reflexes. 1) During the nasal test, the results are 100% for the positive predictive value (VPp) and 83.3% for the negative predictive value (VPn); 2) These results are respectively 84.6% and 35.9% during the swallowing test. Regarding screening for silent aspiration, 1) during the nasal test, the results are 62.5% for the positive predictive value (VPp) and 36.3% for the negative predictive value (VPn); 2) These results are respectively 54.5% and 26.6% during the swallowing test. This preliminary study points out the lack of predictive value of the nasal test and the swallow test for the silent aspirations. However the results could be useful for other researchers developing other tests in this area.

The prevalence and effects of aspiration among neonates at the time of discharge.

PubMed

Karsch, Emily; Irving, Sharon Y; Aylward, Brandon S; Mahle, William T

2017-09-01

Neonates undergoing heart surgery for CHD are at risk for postoperative gastrointestinal complications and aspiration events. There are limited data regarding the prevalence of aspiration after neonatal cardiothoracic surgery; thus, the effects of aspiration events on this patient population are not well understood. This retrospective chart review examined the prevalence and effects of aspiration among neonates who had undergone cardiac surgery at the time of their discharge. Introduction This study examined the prevalence of aspiration among neonates who had undergone cardiac surgery. Demographic data regarding these patients were analysed in order to determine risk factors for postoperative aspiration. Post-discharge feeding routes and therapeutic interventions were extracted to examine the time spent using alternate feeding routes because of aspiration risk or poor caloric intake. Modified barium swallow study results were used to evaluate the effectiveness of the test as a diagnostic tool. Materials and methods A retrospective study was undertaken of neonates who had undergone heart surgery from July, 2013 to January, 2014. Data describing patient demographics, feeding methods, and follow-up visits were recorded and compared using a χ2 test for goodness of fit and a Kaplan-Meier graph. The patient population included 62 infants - 36 of whom were male, and 10 who were born with single-ventricle circulation. The median age at surgery was 6 days (interquartile range=4 to 10 days). Modified barium swallow study results showed that 46% of patients (n=29) aspirated or were at risk for aspiration, as indicated by laryngeal penetration. In addition, 48% (n=10) of subjects with a negative barium swallow or no swallow study demonstrated clinical aspiration events. Tube feedings were required by 66% (n=41) of the participants. The median time spent on tube feeds, whether in combination with oral feeds or exclusive use of a nasogastric or gastric tube, was 54 days; 44% (n

Aiming High: The Educational and Occupational Aspirations and of Young Disabled People

ERIC Educational Resources Information Center

Burchardt, Tania

2004-01-01

This article provides an overview of the aspirations and expectations disabled teenagers form for their future education and employment and the factors which are associated with positive aspirations. After reviewing what is already known about the formation of aspirations in general, and among young disabled people in particular, Tania Burchardt…

Turban pin aspiration: new fashion, new syndrome.

PubMed

Ilan, Ophir; Eliashar, Ron; Hirshoren, Nir; Hamdan, Kasem; Gross, Menachem

2012-04-01

Turban pin aspiration syndrome is a new clinical entity afflicting young Islamic girls wearing a turban.The goal of this study was to present our experience in diagnosis and treatment of this new entity, define its clinical and epidemiologic features, and shed a new light on the role of fashion in the increased incidence. A retrospective study in a tertiary university hospital. Review of clinical parameters and epidemiologic features of 26 patients diagnosed with turban pin aspiration syndrome admitted to the Hadassah-Hebrew University Hospitals in Jerusalem from 1990 to 2010. All patients were Muslim females with an average age of 16 years. In all cases, the history was positive for accidental aspiration. Most of the pins were located in the trachea (42%). In 20 cases, the pins were extracted by rigid bronchoscopy without major complications. Fluoroscopy-assisted rigid bronchoscopy was used successfully in three cases. In one case, the object was self-ejected by coughing before the bronchoscopy, and two patients were referred to the chest unit for thoracotomy. Clinicians should be aware of this distinct form of foreign body aspiration, its method of diagnosis, and extraction techniques. A cultural investigation showed a difference in the turban-fastening technique of young girls as compared with their mothers. Removal by rigid bronchoscopy is a safe method with a high success rate and should be considered as the preferred extraction method of choice. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Aspiration in injections: should we continue or abandon the practice?

PubMed Central

Sepah, Yasir; Samad, Lubna; Altaf, Arshad; Halim, Muhammad Sohail; Rajagopalan, Nithya; Javed Khan, Aamir

2017-01-01

Aspiration during any kind of injection is meant to ensure that the needle tip is at the desired location during this blind procedure. While aspiration appears to be a simple procedure, it has generated a lot of controversy concerning the perceived benefits and indications. Advocates and opponents of aspiration both make logically sound claims. However, due to scarcity of available data, there is no evidence that this procedure is truly beneficial or unwarranted. Keeping in view the huge number of injections given worldwide, it is important that we draw attention to key questions regarding aspiration that, up till now, remain unanswered. In this review, we have attempted to gather and present literature on aspiration both from published and non-published sources in order to provide not only an exhaustive review of the subject, but also a starting point for further studies on more specific areas requiring clarification. A literature review was conducted using the US National Institute of Health’s PubMed service (including Medline), Google Scholar and Scopus. Guidelines provided by the World Health Organization, Safe Injection Global Network, International Council of Nursing, Center for Disease Control, US Federal Drug Agency, UK National Health Services, British Medical Association, Europe Nursing and Midwifery Council, Public Health Agency Canada, Pakistan Medical Association and International Organization of Standardization recommendations 7886 parts 1-4 for sterile hypodermics were reviewed for relevant information. In addition, curricula of several medical/nursing schools from India, Nigeria and Pakistan, the US pharmacopeia Data from the WHO Program for International Drug Monitoring network in regard to adverse events as a result of not aspirating prior to injection delivery were reviewed. Curricula of selected major medical/nursing schools in India, Nigeria and Pakistan, national therapeutic formularies, product inserts of most commonly used drugs and other

The Perceived Value of Education and Educational Aspirations in the Czech Republic: Changes in the Determination of Educational Aspirations between 1989 and 2003

ERIC Educational Resources Information Center

Mateju, Petr; Smith, Michael L.

2009-01-01

This article compares the changes in the determination of educational aspirations from the end of the communist period in 1989 to 2003, focusing on a single postcommunist country, the Czech Republic. The Czech case is particularly relevant for comparative research on educational inequality and aspirations, as previous studies have shown…

Life Chances, Lifestyle and Everyday Aspirational Strategies and Tactics

ERIC Educational Resources Information Center

Kenway, Jane; Hickey-Moody, Anna

2011-01-01

The notion of raising the aspirations of socially disadvantaged students is a key policy strategy in for enhancing such students' participation in higher education. However, this strategy runs the risk of being simplistic and ineffective unless it is informed by research on the links between aspirations and such students' changing life experiences…

Self-efficacy beliefs as shapers of children's aspirations and career trajectories.

PubMed

Bandura, A; Barbaranelli, C; Caprara, G V; Pastorelli, C

2001-01-01

This prospective study tested with 272 children a structural model of the network of sociocognitive influences that shape children's career aspirations and trajectories. Familial socioeconomic status is linked to children's career trajectories only indirectly through its effects on parents' perceived efficacy and academic aspirations. The impact of parental self-efficacy and aspirations on their children's perceived career efficacy and choice is, in turn, entirely mediated through the children's perceived efficacy and academic aspirations. Children's perceived academic, social, and self-regulatory efficacy influence the types of occupational activities for which they judge themselves to be efficacious both directly and through their impact on academic aspirations. Perceived occupational self-efficacy gives direction to the kinds of career pursuits children seriously consider for their life's work and those they disfavor. Children's perceived efficacy rather than their actual academic achievement is the key determinant of their perceived occupational self-efficacy and preferred choice of worklife. Analyses of gender differences reveal that perceived occupational self-efficacy predicts traditionality of career choice.

Association of blood lipids with Alzheimer's disease: A comprehensive lipidomics analysis.

PubMed

Proitsi, Petroula; Kim, Min; Whiley, Luke; Simmons, Andrew; Sattlecker, Martina; Velayudhan, Latha; Lupton, Michelle K; Soininen, Hillka; Kloszewska, Iwona; Mecocci, Patrizia; Tsolaki, Magda; Vellas, Bruno; Lovestone, Simon; Powell, John F; Dobson, Richard J B; Legido-Quigley, Cristina

2017-02-01

The aim of this study was to (1) replicate previous associations between six blood lipids and Alzheimer's disease (AD) (Proitsi et al 2015) and (2) identify novel associations between lipids, clinical AD diagnosis, disease progression and brain atrophy (left/right hippocampus/entorhinal cortex). We performed untargeted lipidomic analysis on 148 AD and 152 elderly control plasma samples and used univariate and multivariate analysis methods. We replicated our previous lipids associations and reported novel associations between lipids molecules and all phenotypes. A combination of 24 molecules classified AD patients with >70% accuracy in a test and a validation data set, and we identified lipid signatures that predicted disease progression (R 2  = 0.10, test data set) and brain atrophy (R 2  ≥ 0.14, all test data sets except left entorhinal cortex). We putatively identified a number of metabolic features including cholesteryl esters/triglycerides and phosphatidylcholines. Blood lipids are promising AD biomarkers that may lead to new treatment strategies. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Black Women's Career Aspirations

ERIC Educational Resources Information Center

Farley, Jennie; And Others

1977-01-01

A two-page questionnaire dealing with career aspirations and expectations was administered to undergraduates at four institutions. Results suggest Black women as a group predict they will earn less than Black males; white women as a group predict they will earn less than white men but the pay gap is narrower. (Author)

An empirical model of human aspiration in low-velocity air using CFD investigations.

PubMed

Anthony, T Renée; Anderson, Kimberly R

2015-01-01

Computational fluid dynamics (CFD) modeling was performed to investigate the aspiration efficiency of the human head in low velocities to examine whether the current inhaled particulate mass (IPM) sampling criterion matches the aspiration efficiency of an inhaling human in airflows common to worker exposures. Data from both mouth and nose inhalation, averaged to assess omnidirectional aspiration efficiencies, were compiled and used to generate a unifying model to relate particle size to aspiration efficiency of the human head. Multiple linear regression was used to generate an empirical model to estimate human aspiration efficiency and included particle size as well as breathing and freestream velocities as dependent variables. A new set of simulated mouth and nose breathing aspiration efficiencies was generated and used to test the fit of empirical models. Further, empirical relationships between test conditions and CFD estimates of aspiration were compared to experimental data from mannequin studies, including both calm-air and ultra-low velocity experiments. While a linear relationship between particle size and aspiration is reported in calm air studies, the CFD simulations identified a more reasonable fit using the square of particle aerodynamic diameter, which better addressed the shape of the efficiency curve's decline toward zero for large particles. The ultimate goal of this work was to develop an empirical model that incorporates real-world variations in critical factors associated with particle aspiration to inform low-velocity modifications to the inhalable particle sampling criterion.

Individual-Level Predictors of Young Children's Aspirations

ERIC Educational Resources Information Center

Moulton, Vanessa; Flouri, Eirini; Joshi, Heather; Sullivan, Alice

2018-01-01

Often young children already have some ideas about what they want to do in the future. Using data from a large UK cohort study, we investigated the individual determinants of seven-year-old children's aspirations, controlling for parental socio-economic background and parental involvement in learning. At age 7, not all children's aspirations were…

The Relationship between Gender and Aspirations to Senior Management

ERIC Educational Resources Information Center

Litzky, Barrie; Greenhaus, Jeffrey

2007-01-01

Purpose: The purpose of this paper is to examine the relationship of gender, work factors, and non-work factors with aspirations to positions in senior management. A process model of senior management aspirations was developed and tested. Design/methodology/approach: Data were collected via an online survey that resulted in a sample of 368 working…

Diagnostic accuracy of lymphoma established by fine-needle aspiration cytological biopsy

NASA Astrophysics Data System (ADS)

Delyuzar; Amir, Z.; Suryadi, D.

2018-03-01

Based on Globocan data in 2012, it is estimated that about 14,495 Indonesians suffer from lymphoma, both Hodgkin’s lymphoma, and non-Hodgkin’s lymphoma. Some areas of specialization still doubt the accuracy of cytology diagnosis of fine needle aspiration biopsy.This study is a diagnostic test with a cross sectional analytic design to see how the cytology diagnostic accuracy of fine needle aspiration aspirate in lymphoma. It was in Department of Anatomical Pathology Faculty of Medicine USU, Haji Adam Malik Hospital, Dr.Pirngadi hospital, or private clinic in Medan. Peripheral cytology technique biopsy of fine needle aspiration on lymph node subsequently stained with Giemsa, when the cytology of lymphoma is obtained and confirmed by histopathologic examination. Cytology and histopathologic examination will be tested by Diagnostic Test and assessed for its sensitivity and specificity. The diagnostic of lymphoma cytology provides 93.33% sensitivity and 92.31% specificity when confirmed by histopathological examination. Positive predictive value and negative predictive value of 96.55% and 85.71% respectively. In conclusion, the cytology of fine needle aspiration biopsy is accurate enough to be used as a diagnostic tool, so it is advisable to establish a lymphoma diagnosis to perform a needle aspiration biopsy examination.

Bio rapid prototyping by extruding/aspirating/refilling thermoreversible hydrogel.

PubMed

Iwami, K; Noda, T; Ishida, K; Morishima, K; Nakamura, M; Umeda, N

2010-03-01

This paper reports a method for rapid prototyping of cell tissues, which is based on a system that extrudes, aspirates and refills a mixture of cells and thermoreversible hydrogel as a scaffold. In the extruding mode, a cell-mixed scaffold solution in the sol state is extruded from a cooled micronozzle into a temperature-controlled substrate, which keeps the scaffold in the gel state. In the aspiration mode, the opposite process is performed by Bernoulli suction. In the refilling mode, the solution is extruded into a groove created in the aspiration mode. The minimum width of extruded hydrogel pattern is 114 +/- 15 microm by employing a nozzle of diameter 100 microm, and that of aspirated groove was 355 +/- 10 microm using a 500 microm-diameter nozzle. Gum arabic is mixed with the scaffold solution to avoid peeling-off of the gel pattern from the substrate. Patterning of Sf-9 cell tissue is demonstrated, and the stability of the patterned cell is investigated. This system offers a procedure for rapid prototyping and local modification of cell scaffolds for tissue engineering.

[Recommendations for the prevention of foreign body aspiration].

PubMed

Lluna, Javier; Olabarri, Mikel; Domènech, Anna; Rubio, Bárbara; Yagüe, Francisca; Benítez, María T; Esparza, María J; Mintegi, Santiago

2017-01-01

The aspiration of a foreign body remains a common paediatric problem, with serious consequences that can produce both acute and chronic disease. Aspiration usually causes a medical emergency that requires a prompt diagnosis and an urgent therapeutic approach as it may result in the death of the child or severe brain injury. It typically involves organic foreign bodies (mainly food or nuts) aspirated by children under 5 years old, and usually at home. In this statement, the Committee on Safety and Prevention of Non-Intentional Injury in Childhood of the Spanish Paediatrics Association provides a series of recommendations, both educational (while eating and playing), as well as legal, to prevent such episodes. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Rising Aspirations Dampen Satisfaction

ERIC Educational Resources Information Center

Clark, Andrew E.; Kamesaka, Akiko; Tamura, Teruyuki

2015-01-01

It is commonly believed that education is a good thing for individuals. Yet, its correlation with subjective well-being is most often only weakly positive, or even negative, despite the many associated better individual-level outcomes. We here square the circle using novel Japanese data on happiness aspirations. If reported happiness comes from a…

Familial and Economic Influences on the Gender-Related Educational and Occupational Aspirations of Rural Adolescents

PubMed Central

Meece, Judith L.; Askew, Karyl J. S.; Agger, Charlotte A.; Hutchins, Bryan C.; Byun, Soo-yong

2015-01-01

Economic, occupational, and social shifts in rural economies have influenced nuanced changes in the educational and occupational aspirations of rural adolescent women and men. However, there is limited contemporary research that examines the aspirations of rural adolescents at the beginning of the 21st century. Drawing on a sample of 8,756 rural adolescents in the United States, we examine how familial, geographic, and economic variables influence gender-related differences in educational and occupational aspirations. Findings revealed significant gender differences, favoring girls, in youth's educational aspirations, occupational aspirations, and aspirations for nontraditional careers. Results highlight the importance of contextual variables such as parental expectations, family income, and motivation variables in predicting gender-related aspirations of rural youth. PMID:26681990

Cognitive Correlates of Adolescents' Aspirations to Leadership: A Developmental Study.

ERIC Educational Resources Information Center

Singer, Ming

1990-01-01

Examined age and gender differences in leadership aspirations among adolescents (N=130) by measuring overall leadership aspirations, valence-instrumentality expectancies for leadership outcomes, self-efficacy perceptions, and attributions of effective leadership. Found significant gender differences in valence scores and age differences in…

Can nature make us more caring? Effects of immersion in nature on intrinsic aspirations and generosity.

PubMed

Weinstein, Netta; Przybylski, Andrew K; Ryan, Richard M

2009-10-01

Four studies examined the effects of nature on valuing intrinsic and extrinsic aspirations. Intrinsic aspirations reflected prosocial and other-focused value orientations, and extrinsic aspirations predicted self-focused value orientations. Participants immersed in natural environments reported higher valuing of intrinsic aspirations and lower valuing of extrinsic aspirations, whereas those immersed in non-natural environments reported increased valuing of extrinsic aspirations and no change of intrinsic aspirations. Three studies explored experiences of nature relatedness and autonomy as underlying mechanisms of these effects, showing that nature immersion elicited these processes whereas non-nature immersion thwarted them and that they in turn predicted higher intrinsic and lower extrinsic aspirations. Studies 3 and 4 also extended the paradigm by testing these effects on generous decision making indicative of valuing intrinsic versus extrinsic aspirations.

Endotracheal tubes and fluid aspiration: an in vitro evaluation of new cuff technologies.

PubMed

Mariyaselvam, Maryanne Z; Marsh, Lucy L; Bamford, Sarah; Smith, Ann; Wise, Matt P; Williams, David W

2017-03-04

Aspiration of subglottic secretions past the endotracheal tube (ETT) cuff is a prerequisite for developing ventilator-associated pneumonia (VAP). Subglottic secretion drainage (SSD) ETTs reduce aspiration of subglottic secretions and have demonstrated lower VAP rates. We compared the performance of seven SSD ETTs against a non-SSD ETT in preventing aspiration below inflated cuffs. ETTs were positioned vertically in 2 cm diameter cylinders. Four ml of a standard microbial suspension was added above inflated cuffs. After 1 h, aspiration was measured and ETTs demonstrating no leakage were subjected to rotational movement and evaluation over 24 h. Collected aspirated fluid was used to inoculate agar media and incubated aerobically at 37 °C for 24 h. The aspiration rate, volume and number of microorganisms that leaked past the cuff was measured. Experiments were repeated (×10) for each type of ETT, with new ETTs used for each repeat. Best performing ETTs were then tested in five different cylinder diameters (1.6, 1.8, 2.0, 2.2 and 2.4 cm). Experiments were repeated as above using sterile water. Volume and time taken for aspiration past the cuff was measured. Experiments were repeated (×10) for each type of ETT. Results were analysed using non-parametric tests for repeated measures. The PneuX ETT prevented aspiration past the cuff in all experiments. All other ETTs allowed aspiration, with considerable variability in performance. The PneuX ETT was statistically superior in reducing aspiration compared to the SealGuard (p < 0.009), KimVent (p < 0.002), TaperGuard (p < 0.004), Lanz (p < 0.001), ISIS (p < 0.001), SACETT (p < 0.001) and Soft Seal (p < 0.001) ETTs. Of the 4 ETTs tested in differing cylinder sizes, the PneuX significantly reduced aspiration across the range of diameters compared to the SealGuard (p < 0.0001), TaperGuard (p < 0.0001) and KimVent (p < 0.0001) ETTs. ETTs showed substantial variation in fluid

Perioperative pulmonary aspiration is infrequent and low risk in pediatric anesthetic practice.

PubMed

Kelly, Christopher J; Walker, Robert W M

2015-01-01

Recent studies have reported perioperative pulmonary aspiration in pediatric practice to be an uncommon problem associated with low morbidity and mortality. This paper examines the recent publications in both the adult and pediatric literature and looks at some of the potential risk factors involved, both patient and anesthetic, in the development of aspiration of gastric contents. We also look at the risk of severe morbidity following pulmonary aspiration and speculate on possible reasons behind the assertion that pulmonary aspiration in pediatric anesthetic practice is rare and a low-risk event. © 2014 John Wiley & Sons Ltd.

Microincision, aspiration cutter-assisted multifocal iris biopsy for melanoma.

PubMed

Finger, Paul T; Milman, Tatyana

2017-01-19

To describe a minimally invasive method to create multifocal full-thickness surgical iridectomy biopsies. Seven patients suspected to have diffuse iris melanoma underwent multifocal surgical iridectomy biopsy through a single 1.0-mm clear corneal incision. A 25-G inked trocar was used to create one visible corneal portal, through which the anterior chamber was filled with sodium hyaluronate 1%. Then, a 25-G aspiration cutter probe was introduced through the corneal incision such that the aspiration portal was occluded by the iris biopsy sites. Then aspiration (600 mm Hg) cutting (300 cuts per minute) was used to create full- and partial-thickness surgical iridectomy biopsies at multiple locations. After each biopsy the probe was removed, and its contents aspirated into a separate 3-mL syringe (marked by clock hour location). The sodium hyaluronate 1% was removed and wound checked for leakage. Diagnostic specimens were obtained in all cases. Five were found to be diffuse iris melanomas and 2 were indeterminate iris melanocytic proliferations. No patients developed a secondary increase in intraocular pressure, hyphema, infection, cataract, or vision loss. No cases of intraocular tumor dissemination were observed. No patient complained of glare or monocular diplopia. Three of 7 corneal wounds were self-sealing. Multifocal surgical iridectomy biopsy can be minimally invasive and effective allowing for partial- and full-thickness iris biopsy. Use of a 25-G aspiration cutting probe allowed for small incision surgery, rapid rehabilitation, and no significant complications.

Cerebral infarction in the left hemisphere compared with the right hemisphere increases the risk of aspiration pneumonia.

PubMed

Yamamoto, Keiichi; Koh, Hideo; Shimada, Hiroyuki; Takeuchi, Jun; Yamakawa, Yoshihiro; Kawamura, Mayumi; Miki, Takami

2014-12-01

Aspiration pneumonia (AP) following cerebral infarction (CI) has been considered as one of its most serious complications. Nevertheless, there are no reports on the association between the type or location of CI and the incidence of AP. In addition, the association between dysphagia, which leads to aspiration, and the type or location of CI has never been investigated. Therefore we hypothesized that the laterality of CI affects the development of both dysphagia and AP. We performed a retrospective cohort study to examine the association between the laterality of CI and the incidence of dysphagia and AP in 133 patients. AP was found in 6.0% of the group with left CI and in 0.8% of the group with right CI. A univariate logistic regression analysis revealed that left CI was a significant predictor of AP (hazard ratio, 8.81; 95% confidence interval, 1.07-72.59; p = 0.043). Left CI was a significant predictor of AP even after adjusting for age, sex, CI type, or presence of diabetes mellitus. In addition, although the frequency of dysphagia as the direct cause of AP did not differ according to laterality, the frequency of AP that ensued from dysphagia in the left CI group was greater than that observed in the right CI group. The group with left CI from the motor cortex to the internal capsule complicated by dysphagia exhibited a high risk of AP.

The Educational and Employment Aspirations of Adolescents from Areas of High Deprivation in London.

PubMed

Frostick, Caroline; Phillips, Gemma; Renton, Adrian; Moore, Derek

2016-06-01

Adolescents from areas of high deprivation are often assumed to have low aspirations for the future. However, recent research has suggested otherwise and there have been calls for more substantial investigation into the relationship between poverty and aspiration. This article reports levels and variation in aspiration from 1214 adolescents (49.5 % male; 50.5 % female) living in areas of high deprivation across 20 London boroughs. A strength of this study is our large and diverse population of low socio-economic status (SES) adolescents, comprising of white British (22 %), black African (21 %), black Caribbean (9 %), Indian/Pakistani/Bangladeshi/Other Asian (24 %), mixed ethnicity (9 %), and 15 % defining themselves as Other. Our measures indicated a high group level of reported aspiration with notable variations. Females reported higher educational (but not occupational) aspirations than males; white British students reported lower educational and occupational aspirations than other ethnic groups; and black African children reported the highest educational aspirations. Perceived parental support for education had the largest positive association with aspirations. In contrast to previous findings from studies carried out in the United States, aspirations were found to be negatively associated with perceptions of school and school peer environment. These measures explored feelings of safety, happiness and belonging within the school environment and school peer group. We discuss possible explanations for this unexpected finding within our population of adolescents from UK state schools and how it might affect future policy interventions. This study makes an important contribution to the literature on adolescent aspirations because of the unique nature of the data sample and the multiple domains of functioning and aspiration measured.

Resolution of tracheal aspiration after the acute phase of stroke-related oropharyngeal Dysphagia.

PubMed

Terré, Rosa; Mearin, Fermín

2009-04-01

We set out to ascertain the evolution and the clinical and videofluoroscopic (VFS) prognostic factors of aspiration recovery and return to oral intake in patients with stroke and VFS diagnosis of tracheal aspiration. Twenty patients with stroke and VFS diagnosis of tracheal aspiration were prospectively evaluated. Clinical evaluation of oropharyngeal dysphagia and VFS examination were performed at admission and repeated at 1, 3, 6 and 12 months of follow-up. At admission, videofluoroscopy showed 40% of patients to have an increase in oral transit time and 65% impaired tongue control; in the pharyngeal phase, mean pharyngeal transit time was increased in 70% of patients and the time required to trigger the swallowing reflex was delayed in 70%. During follow-up, an improvement was observed, and the number of patients with aspiration decreased progressively (the most significant change occurred at 6 months). Evolution was related to the vascular territory affected: at 1 year, aspiration persisted in 12% of anterior territory lesions vs. 58% of posterior territory lesions. Also, the number of silent aspirators decreased from 35% at baseline to no patients after 3 months. Persistent aspiration at 1 year of follow-up significantly correlated with the following baseline variables: vascular territory, gag reflex abolition, palatoglossal seal alteration and pharyngeal delay time. Swallowing physiology in stroke greatly improved during follow-up, mainly between 3 and 6 months, and the number of aspirations decreased progressively. Prognostic factors for persisting aspiration are posterior vascular territory lesions, oropharyngeal reflex abolition, palatoglossal seal alteration and pharyngeal delay time at baseline.

Coevolutionary dynamics of aspiration and strategy in spatial repeated public goods games

NASA Astrophysics Data System (ADS)

Wu, Te; Fu, Feng; Wang, Long

2018-06-01

The evolutionary dynamics remain largely unknown for spatial populations where individuals are more likely to interact repeatedly. Under this settings, individuals can make their decisions to cooperate or not based on the decisions previously adopted by others in their neighborhoods. Using repeated public goods game, we construct a spatial model and use a statistical physics approach to study the coevolutionary dynamics of aspiration and strategy. Individuals each have an aspiration towards the groups they are involved. According to the outcome of each group, individuals have assessment of whether their aspirations are satisfied. If satisfied, they cooperate next round. Otherwise, they switch to defecting. Results show threshold phenomenon for harsh collective dilemma: cooperators sticking to high levels of aspiration can prevail over defectors, while cooperators with other levels are invariably wiped out. When the collective dilemma is relaxed, cooperation is greatly facilitated by inducing a high level of diversity of aspiration. Snapshots further show the spatial patterns of how this coevolutionary process leads to the emergence of an optimal solution associated with aspiration level, whose corresponding strategy are most prevalent. This optimal solution lies in one and the highest aspiration level allowed, and depends on the intensity of the social dilemma. By removing the memory effect, our results also confirm that repeated interactions can promote cooperation, but to a limited degree.

Factors associated with educational aspirations among adolescents: cues to counteract socioeconomic differences?

PubMed

Madarasova Geckova, Andrea; Tavel, Peter; van Dijk, Jitse P; Abel, Thomas; Reijneveld, Sijmen A

2010-03-24

Our study aims to follow this effort and to explore the association between health, socioeconomic background, school-related factors, social support and adolescents' sense of coherence and educational aspirations among adolescents from different educational tracks and to contribute to the existing body of knowledge on the role of educational aspirations in the social reproduction of health inequalities. We expect that socioeconomic background will contribute to the development of educational aspirations, but this association will be modified by available social and individual resources, which may be particularly favourable for the group of adolescents who are on lower educational tracks, since for them such resources may lead to gaining a higher educational level. We collected data on the socioeconomic background (mother's and father's education and employment status, doubts about affordability of future study), school-related factors (school atmosphere, school conditions, attitudes towards school), perceived social support, sense of coherence (manageability, comprehensibility, meaningfulness) and the self-rated health of a national sample of Slovak adolescents (n = 1992, 53.5% females, mean age 16.9 years). We assessed the association of these factors with educational aspirations, overall and by educational tracks (grammar schools, specialised secondary schools, vocational schools). We found statistically significant associations with educational aspirations for the factors parental educational level, father's unemployment, doubts about the affordability of future study, school atmosphere, attitude towards school, social support from the father and a sense of coherence. Social support from the mother and friends was not associated with educational aspiration, nor was self-rated health. Besides affinity towards school, the determinants of educational aspirations differed among adolescents on different educational tracks. Educational aspirations of grammar school

Factors associated with educational aspirations among adolescents: cues to counteract socioeconomic differences?

PubMed Central

2010-01-01

Background Our study aims to follow this effort and to explore the association between health, socioeconomic background, school-related factors, social support and adolescents' sense of coherence and educational aspirations among adolescents from different educational tracks and to contribute to the existing body of knowledge on the role of educational aspirations in the social reproduction of health inequalities. We expect that socioeconomic background will contribute to the development of educational aspirations, but this association will be modified by available social and individual resources, which may be particularly favourable for the group of adolescents who are on lower educational tracks, since for them such resources may lead to gaining a higher educational level. Methods We collected data on the socioeconomic background (mother's and father's education and employment status, doubts about affordability of future study), school-related factors (school atmosphere, school conditions, attitudes towards school), perceived social support, sense of coherence (manageability, comprehensibility, meaningfulness) and the self-rated health of a national sample of Slovak adolescents (n = 1992, 53.5% females, mean age 16.9 years). We assessed the association of these factors with educational aspirations, overall and by educational tracks (grammar schools, specialised secondary schools, vocational schools). Results We found statistically significant associations with educational aspirations for the factors parental educational level, father's unemployment, doubts about the affordability of future study, school atmosphere, attitude towards school, social support from the father and a sense of coherence. Social support from the mother and friends was not associated with educational aspiration, nor was self-rated health. Besides affinity towards school, the determinants of educational aspirations differed among adolescents on different educational tracks. Educational

Etiology and clinical outcome in dogs with aspiration pneumonia: 88 cases (2004-2006).

PubMed

Kogan, David A; Johnson, Lynelle R; Sturges, Beverly K; Jandrey, Karl E; Pollard, Rachel E

2008-12-01

To evaluate the number and types of underlying disorders detected in dogs with aspiration pneumonia and determine the survival rate among affected dogs. Retrospective case series. Animals-88 dogs with aspiration pneumonia. Medical records were reviewed to identify disease processes that could result in aspiration pneumonia. To assess outcome (ie, survival to discharge from the hospital or nonsurvival), dogs were grouped by the type and number of underlying disease processes. Duration of hospitalization and radiographic severity of disease were evaluated with regard to case outcome. As the cause of aspiration pneumonia, a single underlying disorder was identified in 60 of the 88 dogs; 2 or more diseases were identified in the remaining dogs. Esophageal disease (n = 35), vomiting (34), neurologic disorders (24), laryngeal disease (16), and postanesthetic aspiration (12) were identified most commonly. Overall, 68 dogs survived to discharge from the hospital (survival rate, 77%). Survival rates were comparable among dogs regardless of the underlying cause of aspiration pneumonia. Radiographic severity of disease and duration of hospitalization did not influence survival. Among these study dogs, aspiration pneumonia was associated with a high survival rate. The presence of more than 1 underlying disease associated with aspiration pneumonia did not adversely impact survival rate. Interestingly, radiographic severity of disease and duration of hospitalization were not associated with overall survival rate.

Bladder outlet obstruction treated with transurethral ultrasonic aspiration

NASA Astrophysics Data System (ADS)

Malloy, Terrence R.

1991-07-01

Fifty-nine males with bladder outlet obstruction were treated with transurethral ultrasonic aspiration of the prostate. Utilizing a 26.5 French urethral sheath, surgery was accomplished with a 10 French, 0-700 micron vibration level ultrasonic tip with an excursion rate of 39 kHz. Complete removal of the adenoma was accomplished, followed by transurethral electrocautery biopsies of both lateral lobes to compare pathologic specimens. One-year follow-up revealed satisfactory voiding patterns in 57 of 59 men (96%). Two men developed bladder neck contractures. Pathologic comparisons showed 100% correlation between aspirated and TUR specimens (56 BPH, 3 adeno-carcinoma). Forty-sevel men were active sexually preoperatively (6 with inflatable penile prostheses). Post ultrasonic aspiration, 46 men had erectile function similar to preoperative levels with one patient suffering erectile dysfunction. Forty men (85%) had antegrade ejaculation while 7 (15%) experienced retrograde or retarded ejaculation. No patients were incontinent.

Chronic aspiration of gastric fluid induces the development of obliterative bronchiolitis in rat lung transplants.

PubMed

Li, B; Hartwig, M G; Appel, J Z; Bush, E L; Balsara, K R; Holzknecht, Z E; Collins, B H; Howell, D N; Parker, W; Lin, S S; Davis, R D

2008-08-01

Long-term survival of a pulmonary allograft is currently hampered by obliterative bronchiolitis (OB), a form of chronic rejection that is unique to lung transplantation. While tracheobronchial aspiration from gastroesophageal reflux disease (GERD) has clinically been associated with OB, no experimental model exists to investigate this problem. Using a WKY-to-F344 rat orthotopic left lung transplant model, the effects of chronic aspiration on pulmonary allograft were evaluated. Recipients received cyclosporine with or without 8 weekly aspirations of gastric fluid into the allograft. Six (66.7%) of 9 allografts with aspiration demonstrated bronchioles with surrounding monocytic infiltrates, fibrosis and loss of normal lumen anatomy, consistent with the development of OB. In contrast, none of the allografts without aspiration (n = 10) demonstrated these findings (p = 0.002). Of the grafts examined grossly, 83% of the allografts with chronic aspiration but only 20% without aspiration appeared consolidated (p = 0.013). Aspiration was associated with increased levels of IL-1 alpha, IL-1 beta, IL-6, IL-10, TNF-alpha and TGF-beta in BAL and of IL-1 alpha, IL-4 and GM-CSF in serum. This study provides experimental evidence linking chronic aspiration to the development of OB and suggests that strategies aimed at preventing aspiration-related injuries might improve outcomes in clinical lung transplantation.

"Diesel siphoner's lung": Exogenous lipoid pneumonia following hydrocarbon aspiration.

PubMed

Venkatnarayan, Kavitha; Madan, Karan; Walia, Ritika; Kumar, Jaya; Jain, Deepali; Guleria, Randeep

2014-01-01

Lipoid pneumonia is an unusual and uncommon form of pneumonia caused by aspiration of fatty substances. Hydrocarbon pneumonitis following aspiration of diesel is a form of exogenous lipoid pneumonia wherein, aspirated diesel reaches the alveoli rapidly without evoking any significant cough, but initiates an intense inflammatory reaction in the pulmonary parenchyma. This is a rarely described clinical scenario, although the practice of diesel siphonage from automobiles is a common practice in developing countries. We herein describe a 40-year-old male patient, in whom the diagnosis of lipoid pneumonia was delayed for a long duration and highlight the importance of taking a detailed occupational exposure history in patients with non-resolving pneumonia to rule out the underlying possibility of this rare clinical entity.

[Neuroanatomy of Frontal Association Cortex].

PubMed

Takada, Masahiko

2016-11-01

The frontal association cortex is composed of the prefrontal cortex and the motor-related areas except the primary motor cortex (i.e., the so-called higher motor areas), and is well-developed in primates, including humans. The prefrontal cortex receives and integrates large bits of diverse information from the parietal, temporal, and occipital association cortical areas (termed the posterior association cortex), and paralimbic association cortical areas. This information is then transmitted to the primary motor cortex via multiple motor-related areas. Given these facts, it is likely that the prefrontal cortex exerts executive functions for behavioral control. The functional input pathways from the posterior and paralimbic association cortical areas to the prefrontal cortex are classified primarily into six groups. Cognitive signals derived from the prefrontal cortex are conveyed to the rostral motor-related areas to transform them into motor signals, which finally enter the primary motor cortex via the caudal motor-related areas. Furthermore, it has been shown that, similar to the primary motor cortex, areas of the frontal association cortex form individual networks (known as "loop circuits") with the basal ganglia and cerebellum via the thalamus, and hence are extensively involved in the expression and control of behavioral actions.

The national cost burden of bronchial foreign body aspiration in children.

PubMed

Kim, Irene A; Shapiro, Nina; Bhattacharyya, Neil

2015-05-01

Foreign body aspiration (FBA) continues to be a concerning pediatric problem, accounting for thousands of emergency room visits and more than 100 deaths each year in the United States. The costs incurred with hospitalizations and procedures following these events are the focus of this study. Retrospective review. The Nationwide Inpatient Sample from 2009 to 2011 was analyzed, and all cases with pediatric bronchial foreign body aspirations (International Classification of Diseases-9 codes: 934.0, 934.1, 934.8, and 934.9) were reviewed. Cases were analyzed to determine type of foreign body aspiration, procedural interventions performed, duration of inpatient stay, mortality rate, complications, and posthospitalization disposition. The median length of hospital stay and total costs associated with aspiration events were determined. An estimated 1,908 ± 273 pediatric bronchial FBA patients were admitted annually over the 3-year period (mean age, 3.6 ± 0.3 years; 61.3% ± 1.9% male). The ratio of foreign object aspiration to food aspiration was 5:3. Overall, 56%.0 ± 3.6% of the patients underwent a bronchoscopic procedure for foreign body removal; of those, 41.5% ± 2.5% had a foreign body removed at the time of the endoscopy. The hospital mortality rate associated with bronchial aspiration was 1.8% ± 0.4%; and 2.2% ± 0.5% of patients were diagnosed with anoxic brain injury. The median length of stay was 3 days (25th-75th interquartile range, 1-7 days).The median charges and actual costs per case were $20,820 ($10,800-$53,453) and $6,720 ($3,628-$16,723), respectively. The annual overall inpatient cost associated with pediatric bronchial foreign-body aspiration is approximately $12.8 million. Combined, the rate of death or anoxic brain injury associated with pediatric foreign body is approximately 4%. 2C. © 2014 The American Laryngological, Rhinological and Otological Society, Inc.

Knowledge-driven binning approach for rare variant association analysis: application to neuroimaging biomarkers in Alzheimer's disease.

PubMed

Kim, Dokyoon; Basile, Anna O; Bang, Lisa; Horgusluoglu, Emrin; Lee, Seunggeun; Ritchie, Marylyn D; Saykin, Andrew J; Nho, Kwangsik

2017-05-18

Rapid advancement of next generation sequencing technologies such as whole genome sequencing (WGS) has facilitated the search for genetic factors that influence disease risk in the field of human genetics. To identify rare variants associated with human diseases or traits, an efficient genome-wide binning approach is needed. In this study we developed a novel biological knowledge-based binning approach for rare-variant association analysis and then applied the approach to structural neuroimaging endophenotypes related to late-onset Alzheimer's disease (LOAD). For rare-variant analysis, we used the knowledge-driven binning approach implemented in Bin-KAT, an automated tool, that provides 1) binning/collapsing methods for multi-level variant aggregation with a flexible, biologically informed binning strategy and 2) an option of performing unified collapsing and statistical rare variant analyses in one tool. A total of 750 non-Hispanic Caucasian participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort who had both WGS data and magnetic resonance imaging (MRI) scans were used in this study. Mean bilateral cortical thickness of the entorhinal cortex extracted from MRI scans was used as an AD-related neuroimaging endophenotype. SKAT was used for a genome-wide gene- and region-based association analysis of rare variants (MAF (minor allele frequency) < 0.05) and potential confounding factors (age, gender, years of education, intracranial volume (ICV) and MRI field strength) for entorhinal cortex thickness were used as covariates. Significant associations were determined using FDR adjustment for multiple comparisons. Our knowledge-driven binning approach identified 16 functional exonic rare variants in FANCC significantly associated with entorhinal cortex thickness (FDR-corrected p-value < 0.05). In addition, the approach identified 7 evolutionary conserved regions, which were mapped to FAF1, RFX7, LYPLAL1 and GOLGA3, significantly associated

Sex-Role Ideology and the Aspirations of High School Girls

ERIC Educational Resources Information Center

Gaskell, Jane

1977-01-01

Variables specifically related to sex-role definitions in our society must be considered in accounting for the generally lower aspirations of women since after controlling the variables of social class and academic achievement, sex continues to make a difference in the aspiration levels of high school girls. (MJB)

The Effect of Maternal Employment on Schoolchildren's Educational Aspirations in Korea.

ERIC Educational Resources Information Center

Ju, Dong-Beom; Chung, Il-Hwan

2000-01-01

Examined the relationships between maternal employment and schoolchildren's educational aspirations in Korea. Found that children whose mothers were working full-time had lower educational aspirations, although maternal involvement and parents' educational expectations mitigated these effects. (JPB)

Aspirating Seal Development: Analytical Modeling and Seal Test Rig

NASA Technical Reports Server (NTRS)

Bagepalli, Bharat

1996-01-01

This effort is to develop large diameter (22 - 36 inch) Aspirating Seals for application in aircraft engines. Stein Seal Co. will be fabricating the 36-inch seal(s) for testing. GE's task is to establish a thorough understanding of the operation of Aspirating Seals through analytical modeling and full-scale testing. The two primary objectives of this project are to develop the analytical models of the aspirating seal system, to upgrade using GE's funds, GE's 50-inch seal test rig for testing the Aspirating Seal (back-to-back with a corresponding brush seal), test the aspirating seal(s) for seal closure, tracking and maneuver transients (tilt) at operating pressures and temperatures, and validate the analytical model. The objective of the analytical model development is to evaluate the transient and steady-state dynamic performance characteristics of the seal designed by Stein. The transient dynamic model uses a multi-body system approach: the Stator, Seal face and the rotor are treated as individual bodies with relative degrees of freedom. Initially, the thirty-six springs are represented as a single one trying to keep open the aspirating face. Stops (Contact elements) are provided between the stator and the seal (to compensate the preload in the fully-open position) and between the rotor face and Seal face (to detect rub). The secondary seal is considered as part of the stator. The film's load, damping and stiffness characteristics as functions of pressure and clearance are evaluated using a separate (NASA) code GFACE. Initially, a laminar flow theory is used. Special two-dimensional interpolation routines are written to establish exact film load and damping values at each integration time step. Additionally, other user-routines are written to read-in actual pressure, rpm, stator-growth and rotor growth data and, later, to transfer these as appropriate loads/motions in the system-dynamic model. The transient dynamic model evaluates the various motions, clearances

Pulmonary aspiration under GA: a 13-year audit in a tertiary pediatric unit.

PubMed

Tan, Zihui; Lee, Shu Ying

2016-05-01

Pulmonary aspiration is a known risk of general anesthesia. We aim to find out the incidence, risk factors, and outcome of pulmonary aspiration in our pediatric population. Since 2000, all critical incidents are reported on a standardized audit form. All cases with pulmonary aspiration being reported as a critical incident were identified and their case notes traced to look at the perioperative details. From 2000 to 2013, a total of 102 425 pediatric cases were done in our hospital. Twenty-two cases were reported to have aspirated during anesthesia giving an incidence of 0.02% (1 in 4655). Majority (59.0%) of the children were between the ages of 3-12 and of ASA 1 (54.5%). None of them had any history of pulmonary aspiration. Of the 22 cases, 12 occurred during induction, three during maintenance, three during emergence, three during recovery, and one occurred preinduction. Twelve cases had intravenous induction while the rest received inhalational induction. The type of induction does not appear to affect the incidence of aspiration (OR 1.139 95% CI: 0.457-2.818 P = 0.76). Two cases were found to have a difficult airway during induction and 45.5% were emergency operations. Emergency surgeries put the patient at a higher risk of aspiration (OR 4.321 95% CI: 1.735-10.687 P = 0.001). No mortality was reported. Surgery was canceled for one patient, two had unplanned admissions, seven were admitted to high dependency unit or intensive care unit with two requiring postoperative ventilation. The incidence of aspiration under general anesthesia in our hospital is comparable to published reports. Our audit highlights the fact that pulmonary aspiration although rare mostly occur in healthy ASA 1 and 2 children with no prior history. Emergency surgeries put the patient at a higher risk of aspiration. They occurred usually during induction, a process which tends to be variable (in technique and duration) for pediatric patients. © 2016 John Wiley & Sons Ltd.

UNCERTAINTY IN EARLY OCCUPATIONAL ASPIRATIONS: ROLE EXPLORATION OR AIMLESSNESS?

PubMed Central

Staff, Jeremy; Harris, Angel; Sabates, Ricardo; Briddell, Laine

2014-01-01

Many youth in the United States lack clear occupational aspirations. This uncertainty in achievement ambitions may benefit socioeconomic attainment if it signifies “role exploration,” characterized by career development, continued education, and enduring partnerships. By contrast, uncertainty may diminish attainment if it instead leads to “aimlessness,” involving prolonged education without the acquisition of a degree, residential dependence, and frequent job changes. We use nationally representative data from the National Education Longitudinal Study (NELS) to examine how uncertainty in occupational aspirations in adolescence (age 16) affects wage attainments in young adulthood (age 26). Results suggest that youth with uncertain career ambitions earn significantly lower hourly wages in young adulthood than youth with professional and non-professional aspirations, supporting the view that uncertainty heightens the risk of labor-market problems. PMID:25540465

Evaluation of the natural history of patients who aspirate.

PubMed

Bock, Jonathan M; Varadarajan, Varun; Brawley, Mary C; Blumin, Joel H

2017-12-01

The natural clinical progression of aspiration to eventual pulmonary compromise is not well understood. We hypothesized that dietary modification recommendations, Penetration-Aspiration Scale (PAS) score, and dysphagia etiology would be associated with changes in time to first pulmonary event and overall survival for patients with documented aspiration on radiologic testing. This study identified a cohort of patients with detectable unsensed penetration or aspiration on videofluoroscopic swallowing study (VFSS), and followed this cohort over time for development of pulmonary events and death. We then evaluated the association of aspiration severity and dietary modification recommendations on incidence of these endpoints. Retrospective chart review. A total of 2,616 VFSS exam reports were reviewed from our institution performed between January 1, 2009 and December 31, 2010. Aspiration or unsensed penetration (PAS of 5 or greater) was detected in 564 (21.5%) of these patients, who were then included in the study cohort. Medical records were reviewed retrospectively for development of pulmonary events (pneumonia, pneumonitis, or other life-threatening pulmonary illness) and all-cause mortality for up to 54 months after initial VFSS. Univariate Kaplan-Meier analysis and multivariate Cox regression were performed for time to first pulmonary event and survival predicted by recommended diet, PAS score, and dysphagia etiology. Dysphagia etiology was highly associated with increased development of pulmonary events for some patients, especially those with generalized nonspecific dysphagia due to deconditioning or frailty (hazard ratio [HZ] vs. stroke 2.95, 95% confidence interval [CI]: 1.53-5.69, P = .001) and esophageal dysphagia (HZ: 2.66, 95% CI: 1.17-6.02, P = .019). Dysphagia etiology was also associated with increased mortality for patients with generalized nonspecific dysphagia due to deconditioning or frailty (HZ: 3.32, 95% CI: 2.0-5.52, P < .001), postsurgical

Aspiration-based coevolution of link weight promotes cooperation in the spatial prisoner's dilemma game

NASA Astrophysics Data System (ADS)

Shen, Chen; Chu, Chen; Shi, Lei; Perc, Matjaž; Wang, Zhen

2018-05-01

In this article, we propose an aspiration-based coevolution of link weight, and explore how this set-up affects the evolution of cooperation in the spatial prisoner's dilemma game. In particular, an individual will increase the weight of its link to its neighbours only if the payoff received via this interaction exceeds a pre-defined aspiration. Conversely, if the received payoff is below this aspiration, the link weight with the corresponding neighbour will decrease. Our results show that an appropriate aspiration level leads to a high-cooperation plateau, whereas too high or too low aspiration will impede the evolution of cooperation. We explain these findings with a comprehensive analysis of transition points and with a systematic analysis of typical configuration patterns. The presented results provide further theoretical insights with regards to the impact of different aspiration levels on cooperation in human societies.

Age and Sex Differences in the Vocational Aspirations of Elementary School Children.

PubMed

Hewitt, Lynn Stewart

1975-08-01

Four hypotheses were proposed: (a) boys would aspire to a greater variety of vocations than girls; (b) boys would change their vocational preferences more frequently than girls; (c) older boys would aspire to a broader range of vocations than younger boys; and (d) older girls would aspire to a similar or smaller range of vocations than younger girls. A total of 128 6- and 8-year-old Dutch boys and girls responded to questions concerning their vocational aspirations. All the hypotheses except (b) received support. The results suggested that sex-role expectations for adult occupations are acquired very early and, moreover, strongly circumscribe the range of vocations perceived as appropriate for females.

Tumour cell dispersion by the ultrasonic aspirator during brain tumour resection.

PubMed

Preston, J K; Masciopinto, J; Salamat, M S; Badie, B

1999-10-01

Ultrasonic aspirators are commonly used to resect brain tumours because they allow safe, rapid and accurate removal of diseased tissue. Since ultrasonic aspirators generate a spray of aerosolized irrigating fluid around the instrument tip, we questioned whether this spray might contain viable tumours cells that could contribute to intraoperative spread of tumour fragments. To test this hypothesis, we collected the spray produced during the resection of nine brain tumours with an ultrasonic aspirator and semi-quantitatively analysed it for tumour presence. The aerosolized irrigation fluid was found to contain intact tumour cells or clumps of tumour cells in all nine instances, and there was a trend of increasing tumour cell dispersion with increasing ultrasonic aspiration times. Further examination is required to determine if this intraoperative dispersion of apparently viable tumour fragments contributes to local neoplasm recurrence.

Structural and socio-psychological influences on adolescents’ educational aspirations and subsequent academic achievement

PubMed Central

2011-01-01

Previous literature indicates that educational aspirations are an important predictor of achievement at school and beyond. This paper examines the factors that are associated with high educational aspirations. It also looks at the relationship between aspirations and achievement at the General Certificate of Secondary Education in a deprived area of London. The results show that educational aspirations are associated with individual characteristics. Girls were more likely than boys to express a wish to remain in education beyond the age of 16. For the most academic route post-16, there were substantial ethnic differences, with minority ethnic groups generally being more likely to state a desire to follow this path. Students who were eligible for free school meals tended to have lower aspirations. Socio-psychological variables were also shown to be of importance, particularly self-esteem and psychological distress. Importantly, educational aspirations had a strong association with actual achievement at age 16, remaining associated even after controlling for a number of other variables, including prior achievement. These findings are discussed in light of previous research and potential intervention strategies. PMID:21532940

Efficacy of an opposite position aspiration on resolution of pneumothorax following CT-guided lung biopsy

PubMed Central

Zeng, L-C; Du, Y; Yang, H-F; Xie, M-G; Liao, H-Q; Zhang, Y-D; Li, L; Wang, Q; Hu, L

2015-01-01

Objective: To evaluate the efficacy of aspiration in an opposite position to deal with pneumothorax after CT-guided lung biopsy. Methods: A retrospective study was developed involving 210 patients with pneumothorax who had undergone CT-guided percutaneous core biopsies from January 2012 to March 2014 for various pulmonary lesions. Asymptomatic patients with minimal pneumothorax were treated conservatively. Simple manual aspiration was performed for symptomatic patients with minimal pneumothorax and for all patients with moderate to large pneumothorax. An opposite position aspiration was performed when simple manual aspiration failed. The efficacy of simple manual aspiration and the opposite position aspiration was observed. Results: Among 210 patients with pneumothorax, 128 (61.0%) asymptomatic patients with minimal pneumothorax were treated conservatively. The remaining 82 were treated with attempted simple manual aspiration. Out of these 82 patients, simple manual aspiration was successful in 58 (70.7%, 58/82) cases. The complete and partial regression rates were 17.2% (10/58) and 82.8% (48/58), respectively. In the other 24 patients (29.3%, 24/82), simple aspiration technique was ineffective. An opposite position (from prone to supine or vice versa) was applied, and a new biopsy puncture site was chosen for reaspiration. This procedure was successful in 22 patients but not in 2 patients who had to have a chest tube insertion. The complete and partial regression rates were 25.0% (6/24) and 66.7% (16/24), respectively. Applying the new method, the total effective rate of aspiration improved significantly from 70.7% (58/82) to 97.6% (80/82). Conclusion: The opposite position aspiration can be safe, effective and minimally invasive treatment for CT-guided lung biopsy-induced pneumothorax thus reducing the use of chest tube significantly. Advances in knowledge: (1) Opposite position aspiration can elevate the success rate of aspiration significantly (from 70.7% to 97

Percutaneous CT-guided sacroiliac joint sampling for infection: aspiration, biopsy, and technique.

PubMed

Knipp, David; Simeone, F Joseph; Nelson, Sandra B; Huang, Ambrose J; Chang, Connie Y

2018-04-01

To evaluate methods of CT-guided sacroiliac joint sampling in patients with suspected infection. All CT-guided sacroiliac joint sampling procedures for suspected infection were reviewed for sampling type (aspiration, lavage aspiration, biopsy), microbiology results, and clinical and imaging follow-up. The primary gold standard was anatomic pathology. If pathology was not available, then positive blood culture with the same organism as SIJ sampling, imaging and clinical follow-up, or clinical follow-up only were used. Anterior and posterior joint distention was evaluated by MRI within 7 days of the procedure. A total of 34 patients (age 39 ± 20 (range, 6-75) years; 21 F, 13 M) were included. Aspiration samples only were obtained in 13/34 (38%) cases, biopsy samples only in 9/34 (26%) cases, and both samples in 12/34 (35%) cases. There was an overall 54% sensitivity and 86% specificity. For the aspiration samples, sensitivity and specificity were 60 and 81%, respectively, compared to 45 and 90% for the biopsy samples. In cases with both samples, biopsy did not add additional microbial information. Seventeen (17/34, 50%) patients had an MRI. The anterior joint was more distended than the posterior joint in 15/17 (88%) of patients, and this difference was significant (P = 0.0003). All of these 17 patients had an attempted aspiration by a posterior approach; 6/17 (35%) resulted in a successful aspiration. Aspiration of the sacroiliac joint has a higher sensitivity than biopsy and should always be attempted first. MRI may be helpful for procedure planning.

Utility of Pulse Oximetry to Detect Aspiration: An Evidence-Based Systematic Review.

PubMed

Britton, Deanna; Roeske, Amy; Ennis, Stephanie K; Benditt, Joshua O; Quinn, Cassie; Graville, Donna

2018-06-01

Pulse oximetry is a commonly used means to measure peripheral capillary oxyhemoglobin saturation (SpO 2 ). Potential use of pulse oximetry to detect aspiration is attractive to clinicians, as it is readily available, quick, and noninvasive. However, research regarding validity has been mixed. This systematic review examining evidence on the use of pulse oximetry to detect a decrease in SpO 2 indicating aspiration during swallowing is undertaken to further inform clinical practice in dysphagia assessment. A multi-engine electronic search was conducted on 8/25/16 and updated on 4/8/17 in accordance with standards published by the Preferred Reporting for Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA). Inclusion criteria included use of pulse oximetry to detect aspiration with simultaneous confirmation of aspiration via a gold standard instrumental study. Keywords included dysphagia or aspiration AND pulse oximetry. Articles meeting criteria were reviewed by two blinded co-investigators. The search yielded 294 articles, from which 19 were judged pertinent and reviewed in full. Ten met the inclusion criteria and all were rated at Level III-2 on the Australian Diagnostic Levels of Evidence. Study findings were mixed with sensitivity ranging from 10 to 87%. Potentially confounding variables were observed in all studies reviewed, and commonly involved defining "desaturation" within a standard measurement error range (~ 2%), mixed populations, mixed viscosities/textures observed during swallowing, and lack of comparison group. The majority of studies failed to demonstrate an association between observed aspiration and oxygen desaturation. Current evidence does not support the use of pulse oximetry to detect aspiration.

PSEN1 and PSEN2 gene expression in Alzheimer's disease brain: a new approach.

PubMed

Delabio, Roger; Rasmussen, Lucas; Mizumoto, Igor; Viani, Gustavo-Arruda; Chen, Elizabeth; Villares, João; Costa, Isabela-Bazzo; Turecki, Gustavo; Linde, Sandra Aparecido; Smith, Marilia Cardoso; Payão, Spencer-Luiz

2014-01-01

Presenilin 1 (PSEN1) and presenilin 2 (PSEN2) genes encode the major component of y-secretase, which is responsible for sequential proteolytic cleavages of amyloid precursor proteins and the subsequent formation of amyloid-β peptides. 150 RNA samples from the entorhinal cortex, auditory cortex and hippocampal regions of individuals with Alzheimer's disease (AD) and controls elderly subjects were analyzed with using real-time rtPCR. There were no differences between groups for PSEN1 expression. PSEN2 was significantly downregulated in the auditory cortex of AD patients when compared to controls and when compared to other brain regions of the patients. Alteration in PSEN2 expression may be a risk factor for AD.

Factors Influencing Career Aspirations of Primary and Secondary Grade Students.

ERIC Educational Resources Information Center

Canale, Joseph R.; Dunlap, Linda L.

Many studies have examined factors influencing the career aspirations of high school students, but little has been done to explore this issue with primary school students. This study investigated factors that might influence the career aspirations of children across a broad age spectrum. Students (N=150) from grades 2, 5, 8, and 12 completed…

Career Aspirations of Youth: Untangling Race/Ethnicity, SES, and Gender

ERIC Educational Resources Information Center

Howard, Kimberly A. S.; Carlstrom, Aaron H.; Katz, Andrew D.; Chew, Aaronson Y.; Ray, G. Christopher; Laine, Lia; Caulum, David

2011-01-01

This study examined the influence of gender, socioeconomic status, and race/ethnicity on the career aspirations of over 22,000 8th and 10th grade youth. The top five occupations identified by youth as aspirations included artist, lawyer, musician, FBI agent, and actor/actress. Top occupations were also reported for each gender x socioeconomic…

Higher Educational Aspirations of African American Male High School Students

ERIC Educational Resources Information Center

Kester, Jonathan

2017-01-01

This quantitative study examined the influence of family, school, and peers on the educational aspirations of African American male high school students in the ninth and tenth grade who live in a small Midwest town. Increasing the higher education aspirations of African American males is the first step needed to attend college, which according to…

Complement mRNA in the mammalian brain: responses to Alzheimer's disease and experimental brain lesioning.

PubMed

Johnson, S A; Lampert-Etchells, M; Pasinetti, G M; Rozovsky, I; Finch, C E

1992-01-01

This study describes evidence in the adult human and rat brain for mRNAs that encode two complement (C) proteins, C1qB and C4. C proteins are important effectors of humoral immunity and inflammation in peripheral tissues but have not been considered as normally present in brain. Previous immunocytochemical studies showed that C proteins are associated with plaques, tangles, and dystrophic neurites in Alzheimer's disease (AD), but their source is unknown. Combined immunocytochemistry and in situ hybridization techniques show C4 mRNA in pyramidal neurons and C1qB mRNA in microglia. Primary rat neuron cultures also show C1qB mRNA. In the cortex from AD brains, there were two- to threefold increases of C1qB mRNA and C4 mRNA, and increased C1qB mRNA prevalence was in part associated with microglia. As a model for AD, we examined entorhinal cortex perforant path transection in the rat brain, which caused rapid increases of C1qB mRNA in the ipsilateral, but not contralateral, hippocampus and entorhinal cortex. The role of brain-derived acute and chronic C induction during AD and experimental lesions can now be considered in relation to functions of C proteins that pertain to cell degeneration and/or cell preservation and synaptic plasticity.

Aspiration-based coevolution of link weight promotes cooperation in the spatial prisoner's dilemma game

PubMed Central

Shen, Chen; Chu, Chen; Shi, Lei

2018-01-01

In this article, we propose an aspiration-based coevolution of link weight, and explore how this set-up affects the evolution of cooperation in the spatial prisoner's dilemma game. In particular, an individual will increase the weight of its link to its neighbours only if the payoff received via this interaction exceeds a pre-defined aspiration. Conversely, if the received payoff is below this aspiration, the link weight with the corresponding neighbour will decrease. Our results show that an appropriate aspiration level leads to a high-cooperation plateau, whereas too high or too low aspiration will impede the evolution of cooperation. We explain these findings with a comprehensive analysis of transition points and with a systematic analysis of typical configuration patterns. The presented results provide further theoretical insights with regards to the impact of different aspiration levels on cooperation in human societies. PMID:29892454

Clearance of bile and trypsin in rat lungs following aspiration of human gastric fluid.

PubMed

Leung, Jason H; Chang, Jui-Chih; Foltz, Emily; Bell, Sadé M; Pi, Cinthia; Azad, Sassan; Everett, Mary Lou; Holzknecht, Zoie E; Sanders, Nathan L; Parker, William; Davis, R Duane; Keshavjee, Shaf; Lin, Shu S

2016-01-01

In the clinical setting, there is no reliable tool for diagnosing gastric aspiration. A potential way of diagnosing gastric fluid aspiration entails bronchoalveolar lavage (BAL) with subsequent examination of the BAL fluid for gastric fluid components that are exogenous to the lungs. The objective of this study was to determine the longevity of the gastric fluid components bile and trypsin in the lung, in order to provide an estimate of the time frame in which assessment of these components in the BAL might effectively be used as a measure of aspiration. Human gastric fluid (0.5 mg/kg) was infused in the right lung of intubated male Fischer 344 rats (n = 30). Animals were sacrificed at specified times following the experimentally induced aspiration, and bronchoalveolar lavage fluid (BALF) was collected. Bile concentrations were analyzed by an enzyme-linked chromatogenic method, and the concentration of trypsin was quantified using an ELISA. Data were analyzed using non-linear regression and a one-phase decay equation. In this experimental model, the half-life of bile was 9.3 hours (r(2) = 0.81), and the half-life of trypsin was 9.0 hours (r(2) = 0.68). The half-lives of bile and trypsin in the rodent aspiration model suggest that the ability to detect aspiration may be limited to a few days post-aspiration. If studies using rats are any indication, it may be most effective to collect BAL samples within the first 24 hours of suspected aspiration events in order to detect aspiration.

Promotion of cooperation induced by appropriate payoff aspirations in a small-world networked game

NASA Astrophysics Data System (ADS)

Chen, Xiaojie; Wang, Long

2008-01-01

Based on learning theory, we adopt a stochastic learning updating rule to investigate the evolution of cooperation in the Prisoner’s Dilemma game on Newman-Watts small-world networks with different payoff aspiration levels. Interestingly, simulation results show that the mechanism of intermediate aspiration promoting cooperation resembles a resonancelike behavior, and there exists a ping-pong vibration of cooperation for large payoff aspiration. To explain the nontrivial dependence of the cooperation level on the aspiration level, we investigate the fractions of links, provide analytical results of the cooperation level, and find that the simulation results are in close agreement with analytical ones. Our work may be helpful in understanding the cooperative behavior induced by the aspiration level in society.

Adolescent Occupational Aspirations: Test of Gottfredson's Theory of Circumscription and Compromise

ERIC Educational Resources Information Center

Cochran, Daria B.; Wang, Eugene W.; Stevenson, Sarah J.; Johnson, Leah E.; Crews, Charles

2011-01-01

The authors investigated the relationship between adolescent occupational aspirations and midlife career success. The model for adolescent occupational aspirations was derived from Gottfredson's (1981) theory of circumscription and compromise. The authors hypothesized that parental socioeconomic status (SES), ability, and gender predict adolescent…

Cooperation guided by the coexistence of imitation dynamics and aspiration dynamics in structured populations

NASA Astrophysics Data System (ADS)

Xu, Kuangyi; Li, Kun; Cong, Rui; Wang, Long

2017-02-01

In the framework of the evolutionary game theory, two fundamentally different mechanisms, the imitation process and the aspiration-driven dynamics, can be adopted by players to update their strategies. In the former case, individuals imitate the strategy of a more successful peer, while in the latter case individuals change their strategies based on a comparison of payoffs they collect in the game to their own aspiration levels. Here we explore how cooperation evolves for the coexistence of these two dynamics. Intriguingly, cooperation reaches its lowest level when a certain moderate fraction of individuals pick aspiration-level-driven rule while the others choose pairwise comparison rule. Furthermore, when individuals can adjust their update rules besides their strategies, either imitation dynamics or aspiration-driven dynamics will finally take over the entire population, and the stationary cooperation level is determined by the outcome of competition between these two dynamics. We find that appropriate synergetic effects and moderate aspiration level boost the fixation probability of aspiration-driven dynamics most effectively. Our work may be helpful in understanding the cooperative behavior induced by the coexistence of imitation dynamics and aspiration dynamics in the society.

Primary cutaneous aspergillosis from Tamilnadu diagnosed by fine needle aspiration cytology

PubMed Central

Venugopal, Taralakshmi V.; Venugopal, Pankajalakshmi V.

2012-01-01

Aspergillus are ubiquitous and more than 30 species have been reported to be involved in human infection. Most of the cases occur in immunocompromised patients and are disseminated in the blood. Primary cutaneous aspergillosis in immunocompetent hosts is rare. We report a unique case of primary cutaneous aspergillosis in an immunocompetent patient diagnosed by fine needle aspiration cytology. The characteristic ascocarp and ascospores of Aspergillus species were found in the aspirate and Aspergillus glaucus was isolated in pure culture. The case is presented to increase the awareness of the usefulness of fine needle aspiration cytology for diagnosing fungal infections. PMID:24371752

An investigation of the associations between contingent self-worth and aspirations among Iranian university students.

PubMed

Sabzehara, Milad; Ferguson, Yuna Lee; Sarafraz, Mehdi Reza; Mohammadi, Mostafa

2014-01-01

This study investigated the novel associations between intrinsic and extrinsic aspirations and internal and external domains of contingent self-worth among a sample of 502 Iranian university students. We found a meaningful pattern showing that intrinsic aspirations were positively associated with internal domains, whereas extrinsic aspirations were positively associated with external domains. Our survey data also suggested that the factor structure of the Aspiration Index, as well as the factor structure of the Contingencies of Self-Worth Scale in our Iranian sample were consistent with factor structures of foreign samples. Finally, the types of aspirations and domains of contingencies of self-worth meaningfully predicted variables related to well-being, confirming previous research. We discuss the nature of the associations between the aspirations and the domains of contingent self-worth.

Lifelong Learning: Capabilities and Aspirations

ERIC Educational Resources Information Center

Ilieva-Trichkova, Petya

2016-01-01

The present paper discusses the potential of the capability approach in conceptualizing and understanding lifelong learning as an agency process, and explores its capacity to guide empirical studies on lifelong learning. It uses data for 20 countries from the Adult Education Survey (2007; 2011) and focuses on aspirations for lifelong learning. The…

Recurrent laryngeal nerve reinnervation for management of aspiration in a subset of children.

PubMed

Zur, Karen B; Carroll, Linda M

2018-01-01

Pediatric aspiration is a multifactorial process that is often complex to manage. Recurrent laryngeal nerve (RLN) injury can cause glottic insufficiency and aspiration. We describe three cases of unilateral vocal fold paralysis resulting in aspiration and the successful use of the RLN reinnervation for its treatment. The theory for utilizing the reinnervation procedure is that when glottic closure improves and a less breathy vocalization occurs, then the larynx is better equipped to protect the lower airway and avoid aspiration. Our cases demonstrate stronger voice and improved swallow function, with normalization of modified barium swallow evaluation, at approximately 6-months post reinnervation. Copyright © 2017. Published by Elsevier B.V.

Clearance of bile and trypsin in rat lungs following aspiration of human gastric fluid

PubMed Central

Leung, Jason H.; Chang, Jui-Chih; Foltz, Emily; Bell, Sadé M.; Pi, Cinthia; Azad, Sassan; Everett, Mary Lou; Holzknecht, Zoie E.; Sanders, Nathan L.; Parker, William; Davis, R. Duane; Keshavjee, Shaf; Lin, Shu S.

2016-01-01

ABSTRACT Purpose: In the clinical setting, there is no reliable tool for diagnosing gastric aspiration. A potential way of diagnosing gastric fluid aspiration entails bronchoalveolar lavage (BAL) with subsequent examination of the BAL fluid for gastric fluid components that are exogenous to the lungs. The objective of this study was to determine the longevity of the gastric fluid components bile and trypsin in the lung, in order to provide an estimate of the time frame in which assessment of these components in the BAL might effectively be used as a measure of aspiration. Materials and Methods: Human gastric fluid (0.5 mg/kg) was infused in the right lung of intubated male Fischer 344 rats (n = 30). Animals were sacrificed at specified times following the experimentally induced aspiration, and bronchoalveolar lavage fluid (BALF) was collected. Bile concentrations were analyzed by an enzyme-linked chromatogenic method, and the concentration of trypsin was quantified using an ELISA. Data were analyzed using non-linear regression and a one-phase decay equation. Results: In this experimental model, the half-life of bile was 9.3 hours (r 2 = 0.81), and the half-life of trypsin was 9.0 hours (r 2 = 0.68). Conclusions: The half-lives of bile and trypsin in the rodent aspiration model suggest that the ability to detect aspiration may be limited to a few days post-aspiration. If studies using rats are any indication, it may be most effective to collect BAL samples within the first 24 hours of suspected aspiration events in order to detect aspiration. PMID:26873328

Desired Destinations of Homeless Women: Realizing Aspirations Within the Context of Homelessness.

PubMed

Biederman, Donna J; Forlan, Nicole

2016-08-01

Despite recent decreases, homelessness remains a substantial problem in the United States. Homelessness is associated with poor health, and homeless women experience earlier mortality than their housed counterparts. Understanding the aspirations of homeless women may offer service providers avenues for intervention to increase well-being among this vulnerable population. This study, a secondary analysis of transcribed interviews (n = 20), provides insight into the aspirations of homeless women. Opportunities for service providers to intervene on these aspirations within the context of homelessness are offered.

Aspiration sclerotherapy for hydroceles in the tropics.

PubMed

Musa, M T; Fahal, A H; el Arabi, Y E

1995-10-01

To assess the usefulness of aspiration sclerotherapy in the treatment of hydroceles in the tropics. This prospective study included 82 patients with 94 primary vaginal hydroceles of which 62 hydroceles were treated by aspiration and tetracycline hydrochloride sclerotherapy as an outpatient procedure (mean age of patients 56.5 years, range 40-82) and 28 were treated surgically and included as controls (mean age 52.4 years, range 40-70). All patients were followed for a year. In the sclerotherapy group, the overall cure rate after a year was 95%. Few complications were encountered in this group: six patients (10%) experienced pain during the procedure, seven patients (12%) had local infection and three patients (5%) developed haematoma. No recurrence was encountered in the surgical group, seven patients (25%) had infection and two patients (7%) developed haematoma. The mean hospital stay for the surgical group was 3.4 +/- 1.3 days (range 1-7). Four patients with thick-walled hydroceles had persistent swelling after sclerotherapy, the recurrence of which dissatisfied the patients. Aspiration sclerotherapy for thin-walled hydroceles proved to be a curative, simple, safe and cost-effective out-patient procedure. It can be an alternative to surgery in developing countries where resources are limited.

Fine needle aspiration cytology of parathyroid lesions.

PubMed

Heo, Ilyeong; Park, Sunhoo; Jung, Chang Won; Koh, Jae Soo; Lee, Seung-Sook; Seol, Hyesil; Choi, Hee Seung; Cho, Soo Youn

2013-10-01

There has been an increase in the use of fine needle aspiration cytology (FNAC) for the diagnosis of parathyroid lesions (PLs). Differentiation between a thyroid lesion and a PL is not easy because of their similar features. We reviewed parathyroid aspirates in our institution and aimed to uncover trends in diagnostic criteria. We selected 25 parathyroid aspirates (from 6 men and 19 women) confirmed surgically or immunohistochemically from 2006 to 2011. Major architectural findings of PLs include scattered naked nuclei, loose clusters, a papillary pattern with a fibrovascular core, tight clusters, and a follicular pattern. These architectures were commonly admixed with one another. Cytological features included anisokaryosis, stippled chromatin, a well-defined cell border, and oxyphilic cytoplasm. Eighteen of the 25 patients were diagnosed with PL using FNAC. Seven patients had been misdiagnosed with atypical cells (n=2), benign follicular cells (n=2), adenomatous goiter (n=2) and metastatic carcinoma (n=1) in FNAC. Using clinicoradiologic data, the sensitivity of the cytological diagnosis was 86.7%. The cytological sensitivity decreased to 50% without this information. FNAC of PL is easily confused with thyroid lesions. A combination of cytological parameters and clinical data will be required to improve the diagnostic sensitivity of PLs.

Nurses' leadership self-efficacy, motivation, and career aspirations.

PubMed

Cziraki, Karen; Read, Emily; Spence Laschinger, Heather K; Wong, Carol

2018-02-05

Purpose This paper aims to test a model examining precursors and outcomes of nurses' leadership self-efficacy, and their aspirations to management positions. Design/methodology/approach A cross-sectional survey of 727 registered nurses across Canada was conducted. Structural equation modelling using Mplus was used to analyse the data. Findings Results supported the hypothesized model: χ 2 (312) = 949.393; CFI = 0.927; TLI = 0.919; RMSEA = 0.053 (0.049-0.057); SRMR 0.044. Skill development opportunities ( ß = 0.20), temporary management roles ( ß = 0.12) and informal mentoring ( ß = 0.11) were significantly related to nurses' leadership self-efficacy, which significantly influenced motivation to lead ( ß = 0.77) and leadership career aspirations ( ß = 0.23). Motivation to lead was significantly related to leadership career aspirations ( ß = 0.50). Practical implications Nurses' leadership self-efficacy is an important determinant of their motivation and intention to pursue a leadership career. Results suggest that nurses' leadership self-efficacy can be influenced by providing opportunities for leadership mastery experiences and mentorship support. Leadership succession planning should include strategies to enhance nurses' leadership self-efficacy and increase front-line nurses' interest in leadership roles. Originality value With an aging nurse leader workforce, it is important to understand factors influencing nurses' leadership aspirations to develop and sustain nursing leadership capacity. This research study makes an important contribution to the nursing literature by showing that nurses' leadership self-efficacy appears to be an important determinant of their motivation to lead and desire to pursue a career as a nurse leader.

A combinatorial model for dentate gyrus sparse coding

DOE PAGES

Severa, William; Parekh, Ojas; James, Conrad D.; ...

2016-12-29

The dentate gyrus forms a critical link between the entorhinal cortex and CA3 by providing a sparse version of the signal. Concurrent with this increase in sparsity, a widely accepted theory suggests the dentate gyrus performs pattern separation—similar inputs yield decorrelated outputs. Although an active region of study and theory, few logically rigorous arguments detail the dentate gyrus’s (DG) coding. We suggest a theoretically tractable, combinatorial model for this action. The model provides formal methods for a highly redundant, arbitrarily sparse, and decorrelated output signal.To explore the value of this model framework, we assess how suitable it is for twomore » notable aspects of DG coding: how it can handle the highly structured grid cell representation in the input entorhinal cortex region and the presence of adult neurogenesis, which has been proposed to produce a heterogeneous code in the DG. We find tailoring the model to grid cell input yields expansion parameters consistent with the literature. In addition, the heterogeneous coding reflects activity gradation observed experimentally. Lastly, we connect this approach with more conventional binary threshold neural circuit models via a formal embedding.« less

Efficacy of Thickened Liquids for Eliminating Aspiration in Head and Neck Cancer: A Systematic Review

PubMed Central

Barbon, Carly E.A.; Steele, Catriona M.

2015-01-01

Objective To appraise the current videofluoroscopic evidence on the reduction of aspiration using thickened liquids in the head and neck cancer population. Data Sources Search terms relating to deglutition or dysphagia or swallow and neoplasms and oncology or head and neck cancer and viscosity or texture and apira or residu* were combined with honey or nectar, xerostomia, respiratory aspiration using Boolean operators. Review Methods A multi-engine literature search identified 337 non-duplicate articles of which 6 were judged to be relevant. These underwent detailed review for study quality and qualitative synthesis. Results The articles reviewed in detail predominantly described heterogeneous study samples with small sample sizes, making for difficult interpretation and generalization of results. Rates of aspiration were typically not reported by bolus consistency, despite the fact that a variety of stimulus consistencies was used during VFSS. Studies confirmed that aspiration is a major concern in the head and neck cancer population and reported a trend towards more frequent aspiration post-(chemo)radiotherapy. Conclusion Overall, the literature on thickened liquids as an intervention to eliminate aspiration in the head and neck cancer population is limited. Because aspiration is known to be prevalent in the head and neck cancer population and thickened liquids are known to eliminate aspiration in other populations, it is important to determine the effectiveness of thickened liquids for reducing aspiration in the head and neck cancer population. PMID:25358345

Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients

PubMed Central

Marian, Thomas; Schröder, Jens; Muhle, Paul; Claus, Inga; Oelenberg, Stephan; Hamacher, Christina; Warnecke, Tobias; Suntrup-Krüger, Sonja; Dziewas, Rainer

2017-01-01

Background Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO2) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO2 ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO2 measurements for the evaluation of aspiration risk in acute stroke patients. Methods Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO2 was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control. Results In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO2 (mean SpO2 without aspiration 95.54 ± 2.7% vs. mean SpO2 with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO2 levels. Conclusions According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients. PMID:28259883

Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients.

PubMed

Marian, Thomas; Schröder, Jens; Muhle, Paul; Claus, Inga; Oelenberg, Stephan; Hamacher, Christina; Warnecke, Tobias; Suntrup-Krüger, Sonja; Dziewas, Rainer

2017-01-01

Dysphagia is one of the most dangerous symptoms of acute stroke. Various screening tools have been suggested for the early detection of this condition. In spite of conflicting results, measurement of oxygen saturation (SpO2) during clinical swallowing assessment is still recommended by different national guidelines as a screening tool with a decline in SpO2 ≥2% usually being regarded as a marker of aspiration. This paper assesses the sensitivity of SpO2 measurements for the evaluation of aspiration risk in acute stroke patients. Fifty acute stroke patients with moderate to severe dysphagia were included in this study. In all patients, fiberoptic endoscopic evaluation of swallowing (FEES) was performed according to a standardised protocol. Blinded to the results of FEES, SpO2 was monitored simultaneously. The degree of desaturation during/after swallows with aspiration was compared to the degree of desaturation during/after swallows without aspiration in a swallow-to-swallow analysis of each patient. To minimise potential confounders, every patient served as their control. In each subject, a swallow with and a swallow without aspiration were analysed. Overall, aspiration seen in FEES was related to a minor decline in SpO2 (mean SpO2 without aspiration 95.54 ± 2.7% vs. mean SpO2 with aspiration 95.28 ± 2.7%). However, a significant desaturation ≥2% occurred only in 5 patients during/after aspiration. There was no correlation between aspiration/dysphagia severity or the amount of aspirated material and SpO2 levels. According to this study, measurement of oxygen desaturation is not a suitable screening tool for the detection of aspiration in stroke patients. © 2017 The Author(s) Published by S. Karger AG, Basel.

Bounded Aspirations: Rural, African American High School Students and College Access

ERIC Educational Resources Information Center

Means, Darris R.; Clayton, Ashley B.; Conzelmann, Johnathan G.; Baynes, Patti; Umbach, Paul D.

2016-01-01

This qualitative case study explores the career and educational aspirations, college choice process, and college barriers and opportunities of 26 rural, African American high school students. Data included interviews with 26 students and 11 school staff members. Findings suggest that the students' rural context shapes aspirations. In addition,…

Middle School Children's Career Aspirations: Relationship to Adult Occupations and Gender

ERIC Educational Resources Information Center

Schuette, Christine T.; Ponton, Michael K.; Charlton, Margaret L.

2012-01-01

The authors explored the relationship between the career aspirations of 89 preadolescents from low socioeconomic backgrounds and the actual occupations of the working adults in their homes with regard to status, job gender identification, and interest (Holland, 1997). There was a significant relationship between boys' career aspirations and the…

Presenting hydrothorax predicts failure of needle aspiration in primary spontaneous pneumothorax.

PubMed

Wu, Kwok Kei; Lui, Chun Tat; Ho, Chik Leung; Tsui, Kwok Leung; Fung, Hin Tat

2016-06-01

The objective was to evaluate if existence of hydrothorax in initial chest radiograph predicts treatment outcome in patients with primary spontaneous pneumothorax who received needle thoracostomy. This is a retrospective cohort study carried out from January 2011 to August 2014 in 1 public hospital in Hong Kong. All consecutive adult patients aged 18years or above who attended the emergency department with the diagnosis of primary spontaneous pneumothorax with needle aspiration performed as primary treatment were included. Age, smoking status, size of pneumothorax, previous history of pneumothorax, aspirated gas volume and presence of hydropneumothorax in initial radiograph were included in the analysis. The outcome was success or failure of the needle aspiration. Logistic regression was used to identify the predicting factors of failure of needle aspiration. There were a total of 127 patients included. Seventy-three patients (57.5%) were successfully treated with no recurrence upon discharge. Among 54 failure cases, 13 patients (10.2%) failed immediately after procedure as evident by chest radiograph and required second treatment. Forty-one patients (32.3%) failed upon subsequent chest radiographs. Multivariate logistic regression showed factors independently associated with the failure of needle aspiration, which included hydropneumothorax in the initial radiograph (odds ratio [OR]=4.47 [1.56i12.83], P=.005), previous history of pneumothorax (OR=3.92 [1.57-9.79], P=.003), and large size of pneumothorax defined as apex-to-cupola distance ≥5cm (OR=2.75 [1.21-6.26], P=.016). Hydropneumothorax, previous history of pneumothorax, and large size were independent predictors of failure of needle aspiration in treatment of primary spontaneous pneumothorax. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental Investigation of a High Pressure Ratio Aspirated Fan Stage

NASA Technical Reports Server (NTRS)

Merchant, Ali; Kerrebrock, Jack L.; Adamczyk, John J.; Braunscheidel, Edward

2004-01-01

The experimental investigation of an aspirated fan stage designed to achieve a pressure ratio of 3.4:1 at 1500 ft/sec is presented in this paper. The low-energy viscous flow is aspirated from diffusion-limiting locations on the blades and flowpath surfaces of the stage, enabling a very high pressure ratio to be achieved in a single stage. The fan stage performance was mapped at various operating speeds from choke to stall in a compressor facility at fully simulated engine conditions. The experimentally determined stage performance, in terms of pressure ratio and corresponding inlet mass flow rate, was found to be in good agreement with the three-dimensional viscous computational prediction, and in turn close to the design intent. Stage pressure ratios exceeding 3:1 were achieved at design speed, with an aspiration flow fraction of 3.5 percent of the stage inlet mass flow. The experimental performance of the stage at various operating conditions, including detailed flowfield measurements, are presented and discussed in the context of the computational analyses. The sensitivity of the stage performance and operability to reduced aspiration flow rates at design and off design conditions are also discussed.

Bacteriology of aspiration pneumonia in patients with acute coma.

PubMed

Lauterbach, Enise; Voss, Frederik; Gerigk, Roland; Lauterbach, Michael

2014-12-01

Loss of protective airway reflexes in patients with acute coma puts these patients at risk of aspiration pneumonia complicating the course of the primary disease. Available data vary considerably with regard to bacteriology, role of anaerobic bacteria, and antibiotic treatment. Our objective was to research the bacteriology of aspiration pneumonia in acute coma patients who were not pre-treated with antibiotics or hospitalized within 30 days prior to the event. We prospectively analyzed 127 patient records from adult patients admitted, intubated and ventilated to a tertiary medical intensive care unit with acute coma. Bacteriology and antibiotic resistance testing from tracheal aspirate sampled within 24 h after admission, blood cultures, ICU scores (APACHE II, SOFA), hematology, and clinical chemistry were assessed. Patients were followed up until death or hospital discharge. The majority of patients with acute coma suffered from acute cardiovascular disorders, predominantly myocardial infarction, followed by poisonings, and coma of unknown cause. In a majority of our patients, microaspiration resulted in overt infection. Most frequently S. aureus, H. influenzae, and S. pneumoniae were isolated. Anaerobic bacteria (Bacteroides spec., Fusobacteria, Prevotella spec.) were isolated from tracheal aspirate in a minority of patients, and predominantly as part of a mixed infection. Antibiotic monotherapy with a 2nd generation cephalosporin, or a 3rd generation gyrase inhibitor, was most effective in our patients regardless of the presence of anaerobic bacteria.

Flexible needle with integrated optical coherence tomography probe for imaging during transbronchial tissue aspiration

NASA Astrophysics Data System (ADS)

Li, Jiawen; Quirk, Bryden C.; Noble, Peter B.; Kirk, Rodney W.; Sampson, David D.; McLaughlin, Robert A.

2017-10-01

Transbronchial needle aspiration (TBNA) of small lesions or lymph nodes in the lung may result in nondiagnostic tissue samples. We demonstrate the integration of an optical coherence tomography (OCT) probe into a 19-gauge flexible needle for lung tissue aspiration. This probe allows simultaneous visualization and aspiration of the tissue. By eliminating the need for insertion and withdrawal of a separate imaging probe, this integrated design minimizes the risk of dislodging the needle from the lesion prior to aspiration and may facilitate more accurate placement of the needle. Results from in situ imaging in a sheep lung show clear distinction between solid tissue and two typical constituents of nondiagnostic samples (adipose and lung parenchyma). Clinical translation of this OCT-guided aspiration needle holds promise for improving the diagnostic yield of TBNA.

Toxoplasma lymphadenitis diagnosed by fine-needle aspiration cytology: a rare finding.

PubMed

Hosokawa, S; Kusama, Y; Ono, T; Mineta, H

2014-06-01

There are only very few reports of cervical toxoplasma lymphadenitis being diagnosed exclusively via fine-needle aspiration cytology (with serology). We describe a case of toxoplasma lymphadenitis that was successfully diagnosed by fine-needle aspiration cytology. The case involved a male patient who was immunocompromised as a result of recurrent acute myelogenous leukaemia with cervical lymphadenopathy. The biopsy showed typical features of a well-defined pseudocyst containing Toxoplasma gondii tachyzoites. Toxoplasma lymphadenitis is a common cause of lymph node enlargement. Fine-needle aspiration cytology is a useful method for diagnosing and differentiating toxoplasma lymphadenitis from more serious causes of lymphadenopathy, such as metastatic lymphadenopathy or lymphoma.

Elemental Diets May Reduce the Risk of Aspiration Pneumonia in Bedridden Gastrostomy-Fed Patients

PubMed Central

Horiuchi, Akira; Nakayama, Yoshiko; Sakai, Ryosei; Suzuki, Manabu; Kajiyama, Masashi; Tanaka, Naoki

2013-01-01

OBJECTIVES: Our clinical experience suggested that elemental diets were associated with a reduction in aspiration pneumonia among bedridden patients with percutaneous endoscopic gastrostomy (PEG). We compared the effects of elemental and standard liquid diets on the risk of clinical aspiration pneumonia and gastric emptying in bedridden patients receiving PEG feedings. METHODS: Study 1: consecutive bedridden PEG patients received elemental diets or standard liquid diets in the same fashion. The frequency of defecation, diet aspirated from the trachea, and aspiration pneumonia during hospitalization were prospectively recorded. Study 2: a randomized, crossover trial using elemental or standard liquid diets containing 13C sodium acetate as a tracer given to bedridden PEG patients who had experienced aspiration pneumonia. 13C breath tests were performed to estimate gastric emptying. RESULTS: Study 1: 127 patients were enrolled, 60 with elemental and 67 with standard liquid diets. The diet was aspirated from the trachea in none (0%) with the elemental diet vs. 8 (11.9%) with standard liquid diets (P=0.0057); aspiration pneumonia developed none with the elemental diet vs. 5 (7.5%) with standard liquid diets (P=0.031) (number needed to treat 14, 95% confidence interval 7–85). Study 2: 19 patients were enrolled. The elemental diet was associated with a significant increase in the 10, 30 or 50% emptying (excretion) time (P<0.001) and increased the area under the curve (% dose/h) compared with the standard liquid diet (P<0.05). CONCLUSIONS: Elemental diets were associated with more rapid gastric empting and fewer episodes of aspiration than standard liquid diets in bedridden PEG patients. They may be preferred for bedridden PEG patients especially who have experienced aspiration pneumonia. Properly performed randomized-controlled trials are needed to prove this potential benefit. PMID:23399554

RT-06GAMMA KNIFE SURGERY AFTER NAVIGATION-GUIDED ASPIRATION FOR CYSTIC METASTATIC BRAIN TUMORS

PubMed Central

Chiba, Yasuyoshi; Mori, Kanji; Toyota, Shingo; Kumagai, Tetsuya; Yamamoto, Shota; Sugano, Hirofumi; Taki, Takuyu

2014-01-01

Metastatic brain tumors over 3 cm in diameter (volume of 14.1ml) are generally considered poor candidates for Gamma Knife surgery (GKS). We retrospectively assessed the method and efficacy of GKS for large cystic metastatic brain tumors after navigation-guided aspiration under local anesthesia. From September 2007 to April 2014, 38 cystic metastatic brain tumors in 32 patients (12 males, 20 females; mean age, 63.2 years) were treated at Kansai Rosai Hospital. The patients were performed navigation-guided cyst aspiration under local anesthesia, then at the day or the next day, were performed GKS and usually discharged on the day. The methods for preventing of leptomeningeal dissemination are following: 1) puncture from the place whose cerebral thickness is 1 cm or more; 2) avoidance of Ommaya reservoir implantation; and 3) placement of absorbable gelatin sponge to the tap tract. Tumor volume, including the cystic component, decreased from 25.4 ml (range 8.7-84.7 ml) to 11.4 ml (range 2.9-36.7 ml) following aspiration; the volume reduction was approximately 51.6%. Follow-up periods in the study population ranged from 0 to 24 months (median 3.5 months). The overall median survival was 6.7 months. There was no leptomeningeal dissemination related to the aspiration. One patient experienced radiation necrosis after GKS, one patient experienced re-aspiration by failure of aspiration, and two patients experienced surgical resections and one patient experienced re-aspiration by cyst regrowth after GKS. Long-term hospitalization is not desirable for the patients with brain metastases. In japan, Long-term hospitalization is required for surgical resection or whole brain radiation therapy, but only two days hospitalization is required for GKS after navigation-guided aspiration at our hospital. This GKS after navigation-guided aspiration is more effective and less invasive than surgical resection or whole brain radiation therapy.

Elemental diets may reduce the risk of aspiration pneumonia in bedridden gastrostomy-fed patients.

PubMed

Horiuchi, Akira; Nakayama, Yoshiko; Sakai, Ryosei; Suzuki, Manabu; Kajiyama, Masashi; Tanaka, Naoki

2013-05-01

Our clinical experience suggested that elemental diets were associated with a reduction in aspiration pneumonia among bedridden patients with percutaneous endoscopic gastrostomy (PEG). We compared the effects of elemental and standard liquid diets on the risk of clinical aspiration pneumonia and gastric emptying in bedridden patients receiving PEG feedings. Study 1: consecutive bedridden PEG patients received elemental diets or standard liquid diets in the same fashion. The frequency of defecation, diet aspirated from the trachea, and aspiration pneumonia during hospitalization were prospectively recorded. Study 2: a randomized, crossover trial using elemental or standard liquid diets containing (13)C sodium acetate as a tracer given to bedridden PEG patients who had experienced aspiration pneumonia. (13)C breath tests were performed to estimate gastric emptying. Study 1: 127 patients were enrolled, 60 with elemental and 67 with standard liquid diets. The diet was aspirated from the trachea in none (0%) with the elemental diet vs. 8 (11.9%) with standard liquid diets (P=0.0057); aspiration pneumonia developed none with the elemental diet vs. 5 (7.5%) with standard liquid diets (P=0.031) (number needed to treat 14, 95% confidence interval 7-85). Study 2: 19 patients were enrolled. The elemental diet was associated with a significant increase in the 10, 30 or 50% emptying (excretion) time (P<0.001) and increased the area under the curve (% dose/h) compared with the standard liquid diet (P<0.05). Elemental diets were associated with more rapid gastric empting and fewer episodes of aspiration than standard liquid diets in bedridden PEG patients. They may be preferred for bedridden PEG patients especially who have experienced aspiration pneumonia. Properly performed randomized-controlled trials are needed to prove this potential benefit.

Clinical validation of the nursing diagnosis Risk for Aspiration among patients who experienced a cerebrovascular accident.

PubMed

Cavalcante, Tahissa Frota; de Araújo, Thelma Leite; Moreira, Rafaella Pessoa; Guedes, Nirla Gomes; Lopes, Marcos Venicios de Oliveira; da Silva, Viviane Martins

2013-01-01

the study's objective was the clinical validation of the nursing diagnosis Risk for Aspiration among patients who experienced cerebrovascular accidents (CVA). a prospective cohort study was conducted with 24 patients hospitalized due to a CVA. The instrument used to collect the data addressed the risk factors for respiratory aspiration, validated by concept analysis and by experts. the most frequent risk factors for respiratory aspiration were: dysphagia (54.2%) and impaired physical mobility (41.7%). The prevalence of the nursing diagnosis Risk for Aspiration was 58.3% and the prevalence of respiratory aspiration over the span of 48 hours (monitoring period) was 37.5%. Risk factors for dysphagia and impaired physical mobility were significantly associated with respiratory aspiration. the risk factors dysphagia and impaired physical mobility are good predictors of the nursing diagnosis Risk for Aspiration. This study contributed to improving the NANDA-I Taxonomy and the systematization of the nursing process.

Percutaneous aspiration of fluid for management of peritonitis in space

NASA Technical Reports Server (NTRS)

Kirkpatrick, A. W.; Nicolaou, S.; Campbell, M. R.; Sargsyan, A. E.; Dulchavsky, S. A.; Melton, S.; Beck, G.; Dawson, D. L.; Billica, R. D.; Johnston, S. L.;

Cloning Their Own: Aspirant Principals and the School-Based Selection Game

ERIC Educational Resources Information Center

Gronn, Peter; Lacey, Kathy

2006-01-01

In this article, we report data from two projects concerned with the aspirant principals' perspectives about school principal recruitment in three Australian states. In particular, we consider what our informants perceive as factors that inhibit the realisation of their aspirations. These factors include aspects of the operation of school-based…

African American Career Aspirations: Examining the Relative Influence of Internalized Racism

ERIC Educational Resources Information Center

Brown, Danice L.; Segrist, Daniel

2016-01-01

The present study examined the relative influence of aspects of internalized racism on the career aspirations of a sample of African American adults. Participants (N = 315), ranging in age from 18 to 62 years, completed measures of internalized racism and career aspirations online. A hierarchical multiple regression analysis was conducted to…

Phaco-efficiency test and re-aspiration analysis of repulsed particle in phacoemulsification.

PubMed

Kim, Jae-hyung; Ko, Dong-Ah; Kim, Jae Yong; Kim, Myoung Joon; Tchah, Hungwon

2013-04-01

To measure the efficiency of phacoemulsification, we have developed a new experimental model for testing phaco-efficiency and analyzed re-aspiration of repulsed particles. Using a Kitaro wetlab system, a piece of blood agar (BA) was placed in an artificial chamber and the phacoemulsifier was placed horizontally. The settings of the phacoemulsifier (Infiniti, Alcon Laboratories) were 26 cc/min for aspiration, 350 cc/min for vacuum, and 95 cm of bottle height. The time to remove BAs was measured using Ozil 100 %, Ozil 40 %, and longitudinal 40 % of phaco power. The angle between the re-aspirated BA particles and the axis of the phacoemulsifier (re-aspiration zone, degree) was analyzed. The average time (seconds) to remove BAs was lower in the Ozil 100 % and the Ozil 40 % mode than in the longitudinal mode (0.37 ± 0.39, 0.85 ± 0.57, and 2.22 ± 1.40 respectively, P value < 0.01). Repulsion exceeding 1 mm occurred more frequently in the longitudinal mode than in the Ozil 100 % mode (100 % vs 40 %, P value = 0.01, Fisher's exact test). The average of re-aspiration zone was 25.9 ± 14.5 in the longitudinal 40 % and 54.0 ± 23.0 in the Ozil 40 % (P value = 0.016). The Ozil mode was more efficient than the longitudinal mode. In addition, the Ozil mode provided less repulsion and wider aspiration zone.

Foreign body aspiration and language spoken at home: 10-year review.

PubMed

Choroomi, S; Curotta, J

2011-07-01

To review foreign body aspiration cases encountered over a 10-year period in a tertiary paediatric hospital, and to assess correlation between foreign body type and language spoken at home. Retrospective chart review of all children undergoing direct laryngobronchoscopy for foreign body aspiration over a 10-year period. Age, sex, foreign body type, complications, hospital stay and home language were analysed. At direct laryngobronchoscopy, 132 children had foreign body aspiration (male:female ratio 1.31:1; mean age 32 months (2.67 years)). Mean hospital stay was 2.0 days. Foreign bodies most commonly comprised food matter (53/132; 40.1 per cent), followed by non-food matter (44/132; 33.33 per cent), a negative endoscopy (11/132; 8.33 per cent) and unknown composition (24/132; 18.2 per cent). Most parents spoke English (92/132, 69.7 per cent; vs non-English-speaking 40/132, 30.3 per cent), but non-English-speaking patients had disproportionately more food foreign bodies, and significantly more nut aspirations (p = 0.0065). Results constitute level 2b evidence. Patients from non-English speaking backgrounds had a significantly higher incidence of food (particularly nut) aspiration. Awareness-raising and public education is needed in relevant communities to prevent certain foods, particularly nuts, being given to children too young to chew and swallow them adequately.

An Unexpected Complication of Bone Marrow Aspiration and Trephine Biopsy: Arteriovenous Fistula

PubMed Central

Berber, Ilhami; Erkurt, Mehmet Ali; Kuku, Irfan; Kaya, Emin; Kutlu, Ramazan; Koroglu, Mustafa; Yigit, Ali; Unlu, Serkan

2014-01-01

Objective To report a case of arteriovenous fistula (AVF) following bone marrow aspiration and trephine biopsy. Clinical Presentation and Intervention A 76-year-old man was diagnosed with acute myeloblastic leukemia. Pain and hematoma were detected in his left leg and hip 4 days after bone marrow aspiration and trephine biopsy. A pelvic arteriography was performed, and a diagnosis of AVF was made. Conclusion This case shows that clinicians should be aware of AVF, especially in cases with refractory bleeding after bone marrow aspiration and trephine biopsy despite normal blood coagulation parameters. PMID:24481007

CT-guided transthoracic needle biopsy: a comparison between automated biopsy gun and fine needle aspiration.

PubMed

Arakawa, H; Nakajima, Y; Kurihara, Y; Niimi, H; Ishikawa, T

1996-07-01

We retrospectively investigated the diagnostic accuracy and complication rate of transthoracic core biopsy using an automated biopsy gun and compared the findings with those of aspiration needle biopsy. Seventy-three patients underwent 74 core biopsy procedures and 50 patients underwent 52 aspiration biopsy procedures. Of these, a final diagnosis was obtained in 107 lesions with surgery or clinical course. Fifteen patients in which a final diagnosis was not obtained were excluded from the study on diagnostic accuracy. Thus, in the study of diagnostic accuracy, 63 core biopsy procedures for 62 lesions are included. Core biopsy was performed with an 18 G cutting needle using an automated biopsy gun. Aspiration biopsy was performed with a 20 G aspiration needle. Core biopsy yielded sufficient material in 57/63 procedures (90.5%). A correct diagnosis was obtained in 36 procedures (85.7%) for malignant leisons and a specific benign diagnosis was obtained in 11 procedures (52.4%). Aspiration biopsy yielded a correct diagnosis in 26 procedures (81.3%) for malignant leisons and in seven (46.7%) for benign lesions. The overall correct diagnosis were 75.8% and 71.7% with core biopsy and aspiration biopsy, respectively. Core biopsy gave a higher predictive rate than that of aspiration biopsy for both benign and malignant lessons (P < 0.02). Pneumothorax occurred in 18/74 (24.3%) patients with core biopsy and in 18/45 (40.0%) patients with aspiration biopsy. Of these, three with core biopsy and two with aspiration biopsy needed tube drainage. The other complication was haemoptysis, which occurred in six patients following core biopsy and in three after aspiration biopsy. All nine cases subsided spontaneously. There were no fatal complications. Core biopsy with a biopsy gun increase the diagnostic accuracy with a higher histologic predictive rate and no obvious additional risk of complications.

Needle aspiration versus intercostal tube drainage for pneumothorax in the newborn.

PubMed

Bruschettini, Matteo; Romantsik, Olga; Ramenghi, Luca Antonio; Zappettini, Simona; O'Donnell, Colm P F; Calevo, Maria Grazia

2016-01-11

Pneumothorax occurs more frequently in the neonatal period than at any other time of life and is associated with increased mortality and morbidity. It may be treated with either needle aspiration or insertion of a chest tube. The former consists of aspiration of air with a syringe through a needle or an angiocatheter, usually through the second or third intercostal space in the midclavicular line. The chest tube is usually placed in the anterior pleural space passing through the sixth intercostal space into the pleural opening, turned anteriorly and directed to the location of the pneumothorax, and then connected to a Heimlich valve or an underwater seal with continuous suction. To compare the efficacy and safety of needle aspiration and intercostal tube drainage in the management of neonatal pneumothorax. We used the standard search strategy of the Cochrane Neonatal Review group to search the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 11), MEDLINE via PubMed (1966 to 30 November 2015), EMBASE (1980 to 30 November 2015), and CINAHL (1982 to 30 November 2015). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. Randomised controlled trials, quasi-randomised controlled trials and cluster trials comparing needle aspiration (either with the needle or angiocatheter left in situ or removed immediately after aspiration) to intercostal tube drainage in newborn infants with pneumothorax. For each of the included trial, two authors independently extracted data (e.g. number of participants, birth weight, gestational age, kind of needle and chest tube, choice of intercostal space, pressure and device for drainage) and assessed the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). The primary outcomes considered in this review are mortality during the neonatal period and during hospitalisation. One

Murray secretion scale and fiberoptic endoscopic evaluation of swallowing in predicting aspiration in dysphagic patients.

PubMed

Kuo, Chia-Wei; Allen, Clint Tanner; Huang, Chu-Chun; Lee, Chia-Jung

2017-06-01

The objective of this retrospective review is to evaluate the ability of the Murray secretion scale to predict aspiration as determined by fiberoptic endoscopic evaluation of swallowing. Patients with dysphagia undergoing a fiberoptic endoscopic evaluation of swallowing study between January 2013 and November 2015 from a single, tertiary care institution were retrospectively reviewed. The Murray secretion scale and penetration aspiration scale on fiberoptic endoscopic evaluation of swallowing examination were determined. Spearman's correlation analysis, sensitivity, specificity, predictive values, and relative risk evaluating the relationship between the Murray secretion scale and aspiration on fiberoptic endoscopic evaluation of swallowing were calculated. Subgroups of head and neck cancer patients, penetration group, and aspiration group were also analyzed. The mean age of the cases (N = 212) was 62.4 years. Eighty percent were male. There was a strong correlation between Murray secretion scale grade and penetration aspiration scale score (r = 0.785, p < 0.001). The sensitivity and specificity of a Murray secretion scale grade 2 or higher in predicting aspiration were 74 and 90%, respectively. Individuals with a Murray secretion scale grade of 2 or higher were 13.6 times more likely to aspirate than patients with a lower Murray secretion scale grade. All subgroups showed similar trend. Determination of a Murray secretion scale grade, determined by flexible nasopharyngoscopy, may predict patients at high risk for aspiration. In clinical scenarios where more complete assessments of aspiration risk are immediately impossible or impractical, the Murray secretion scale grade may add valuable information to assist in clinical decision-making in patients with dysphagia.

Sex Differences in the Determination of Adolescent Aspirations: A Review of Research.

ERIC Educational Resources Information Center

Marini, Margaret Mooney

1978-01-01

Factors influencing levels of adolescent aspiration are reviewed, including socioeconomic background, academic ability, number of siblings, parental encouragement, mother's employment, academic performance, peer aspirations, dating, and participation in school activities. Although sex differences affect the formation of both educational and…

Parents Influencing Secondary Students' University Aspirations: A Multilevel Approach Using School-SES

ERIC Educational Resources Information Center

Watson, Stuart; Vernon, Lynette; Seddon, Sarah; Andrews, Yolanda; Wang, Angela

2016-01-01

Students' university aspirational capacity and expectancies are key factors in predicting future university participation. Aspirations and expectations to attend university are strongly influenced by parent educational socialisation and school culture. This study investigates associations between students' university discussions with parents and…

Effectiveness of chin-down posture to prevent tracheal aspiration in dysphagia secondary to acquired brain injury. A videofluoroscopy study.

PubMed

Terré, R; Mearin, F

2012-05-01

The chin-down posture is generally recommended in patients with neurogenic dysphagia to prevent tracheal aspiration; however, its effectiveness has not been demonstrated. To videofluoroscopically (VDF) assess the effectiveness of chin-down posture to prevent aspiration in patients with neurogenic dysphagia secondary to acquired brain injury. Randomized, alternating, cross-over study (with and without the chin-down posture) in 47 patients with a VDF diagnosis of aspiration [31 stroke, 16 traumatic brain injury (TBI)] and 25 controls without aspiration (14 stroke, 11 TBI). During the chin-down posture, 55% of patients avoided aspiration (40% preswallow aspiration and 60% aspiration during swallow). The percentage was similar in both etiologies (58% stroke and 50% TBI). Fifty-one percent of patients had silent aspiration; of these, 48% persisted with aspiration while in the chin-down posture. A statistically significant relationship was found between the existence of pharyngeal residue, cricopharyngeal dysfunction, pharyngeal delay time and bolus volume with the persistence of aspiration. The chin-down posture did not change swallow biomechanics in patients without aspiration. Only half the patients with acquired brain injury avoided aspiration during cervical flexion; 48% of silent aspirators continued to aspire during the maneuver. Several videofluoroscopic parameters were related to inefficiency of the maneuver. Therefore, the indication for chin-down posture should be evaluated by videofluoroscopic examination. © 2012 Blackwell Publishing Ltd.

Chemogenetic locus coeruleus activation restores reversal learning in a rat model of Alzheimer's disease.

PubMed

Rorabaugh, Jacki M; Chalermpalanupap, Termpanit; Botz-Zapp, Christian A; Fu, Vanessa M; Lembeck, Natalie A; Cohen, Robert M; Weinshenker, David

2017-11-01

See Grinberg and Heinsen (doi:10.1093/brain/awx261) for a scientific commentary on this article. Clinical evidence suggests that aberrant tau accumulation in the locus coeruleus and noradrenergic dysfunction may be a critical early step in Alzheimer’s disease progression. Yet, an accurate preclinical model of these phenotypes that includes early pretangle tau accrual in the locus coeruleus, loss of locus coeruleus innervation and deficits locus coeruleus/norepinephrine modulated behaviours, does not exist, hampering the identification of underlying mechanisms and the development of locus coeruleus-based therapies. Here, a transgenic rat (TgF344-AD) expressing disease-causing mutant amyloid precursor protein (APPsw) and presenilin-1 (PS1ΔE9) was characterized for histological and behavioural signs of locus coeruleus dysfunction reminiscent of mild cognitive impairment/early Alzheimer’s disease. In TgF344-AD rats, hyperphosphorylated tau was detected in the locus coeruleus prior to accrual in the medial entorhinal cortex or hippocampus, and tau pathology in the locus coeruleus was negatively correlated with noradrenergic innervation in the medial entorhinal cortex. Likewise, TgF344-AD rats displayed progressive loss of hippocampal norepinephrine levels and locus coeruleus fibres in the medial entorhinal cortex and dentate gyrus, with no frank noradrenergic cell body loss. Cultured mouse locus coeruleus neurons expressing hyperphosphorylation-prone mutant human tau had shorter neurites than control neurons, but similar cell viability, suggesting a causal link between pretangle tau accrual and altered locus coeruleus fibre morphology. TgF344-AD rats had impaired reversal learning in the Morris water maze compared to their wild-type littermates, which was rescued by chemogenetic locus coeruleus activation via designer receptors exclusively activated by designer drugs (DREADDs). Our results indicate that TgF344-AD rats uniquely meet several key criteria for a

[Study on pulmonary lesions in which nontuberculous mycobacteria were detected by percutaneous aspiration--a proposal to add "culture positivity of percutaneous aspiration material" to the bacteriological diagnostic criteria of pulmonary nontuberculous mycobacterial diseases].

PubMed

Nakahara, Yasuharu; Mochizuki, Yoshiro; Kawamura, Tetsuji; Sasaki, Shin; Morimoto, Akie; Mizumori, Yasuyuki; Tsukamoto, Hiroaki; Watanabe, Etsuko; Yokoyama, Toshihide

2013-03-01

Culture positivity of percutaneous aspiration material" is not included in the current bacteriological criteria for diagnosis of pulmonary nontuberculous mycobacterial (NTM) diseases, which were published by the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) in 2007 or those released by the Japanese Society for Tuberculosis in 2008. However, percutaneous aspiration is a reliable technique for the detection of causative microorganisms isolated from the focus of infection. We discuss the benefits of including positive culture of percutaneous aspiration material in the bacteriological diagnostic criteria of pulmonary NTM diseases. We reviewed the radiological images and clinical courses of pulmonary diseases in which NTM cultures were obtained from percutaneously aspirated materials at our hospital from 1991 to 2011. Aspiration was carried out under local anesthesia, usually with fluoroscopic guidance. After percutaneous insertion of a 22-gauge needle attached to a 20-mL syringe containing about 3 mL of saline, the lesion specimen was withdrawn together with the saline. After the needle was pulled out, the aspirated material and saline were transferred to test tubes for cytological and microbiological examinations. In patients with thin-walled cavitary lesions, saline was injected into the cavity and then aspirated. Percutaneous aspiration was performed in 2,742 patients and NTM disease was detected in 51 patients. Of these 51 patients, 12 had solitary nodular lesions, and in many of these patients, no NTM bacilli could be detected in the sputa or bronchial washing specimens. Mycobacterium avium was identified in 10 of the 12 cases. Four of these 10 patients were followed up after their diagnosis without any treatment: 3 showed spontaneous reduction in lesion size, while 1 patient's condition remained unchanged. Four of the remaining 6 cases were treated with anti-NTM medications, and lesion size reduced in 2 cases, while no change or

The Functional Dysphagia Scale Is a Useful Tool for Predicting Aspiration Pneumonia in Patients With Parkinson Disease.

PubMed

Lee, Jong Hwa; Lee, Kyeong Woo; Kim, Sang Beom; Lee, Sook Joung; Chun, Sang Myung; Jung, Sung Moon

2016-06-01

To describe the correlation between the functional dysphagia scale and aspiration pneumonia and which characteristics influence the occurrence of aspiration pneumonia in patients with idiopathic Parkinson disease. Fifty-three patients with idiopathic Parkinson disease were prospectively evaluated in this study. Disease severity and functional status were measured by modified Hoehn and Yahr (H&Y) staging, Schwab and England activities of daily living (S-E ADL) scale and Korean version of Mini-Mental State Examination (K-MMSE). Swallowing function was evaluated by the functional dysphagia scale (FDS) and the penetration-aspiration scale (PAS) based on a videofluoroscopic swallowing study. The patients were followed up for 3 months and divided into two groups according to the occurrence of aspiration pneumonia. The correlation between the variables and aspiration pneumonia was analyzed. Eight patients of the 53 patients were allocated to the aspiration pneumonia group and 45 patients to the non-aspiration pneumonia group. The patients in the aspiration pneumonia group had significantly higher H&Y staging, and scored lower on S-E ADL scale and K-MMSE. The patients in the aspiration pneumonia group had significantly higher scores on FDS and PAS. A multiple logistic regression analysis showed that the S-E ADL scale and the FDS were associated with the occurrence of aspiration pneumonia in the patients with Parkinson disease. Given that the FDS can quantitatively assess the functional problems associated with dysphagia, it can be clinically effective in predicting the occurrence of aspiration pneumonia, and the FDS and the S-E ADL scale could be predictive variables for aspiration pneumonia in patients with Parkinson disease.

A novel pneumatic micropipette aspiration method using a balance pressure model.

PubMed

Zhao, Qili; Wu, Ming; Cui, Maosheng; Qin, Yanding; Yu, Jin; Sun, Mingzhu; Zhao, Xin; Feng, Xizeng

2013-12-01

This paper presents a novel micropipette aspiration (MA) method based on a common pneumatic micro-injection system. This method is the first to quantify the influence of capillary effect on aspiration pressure using a balance pressure model, and in return, uses the capillary effect to quantify the aspiration pressure. Subsequently, the seal between the cell and the micropipette is detected to judge and exclude the ineffective MA attempts. The rationality of the balance pressure model is validated by the designed micropipette-filling experiments. Through applied to elasticity-determination of the cells with different sizes, the feasibility and versatility of this MA method are proved. With abilities to quantify aspiration pressures and detect the seam between the cell and the micropipette, our method is expected to advance the application of the commercial pneumatic injector in the MA of cells. Moreover, with the quantified volume of the liquid entering into the micropipette during MA process, our method also has a potential applicability to the study of the permeability of the cell membrane in the future.

Career Aspirations of Adolescent Girls: Effects of Achievement Level, Grade, and Single-Sex School Environment.

ERIC Educational Resources Information Center

Watson, Cary M.; Quatman, Teri; Edler, Erik

2002-01-01

Compared high achieving adolescent girls' ideal and real career aspirations to adolescent boys' aspirations, examining the influence of grade level, achievement level, and an all-girls school environment. At all achievement levels, girls were commensurate with boys in ideal and realistic career aspirations. High achieving girls exceeded the…

Insurance status as a risk factor for foreign body ingestion or aspiration.

PubMed

Arjmand, E M; Muntz, H R; Stratmann, S L

1997-10-18

To determine whether the lack of private health insurance places children at increased risk for foreign body ingestion or aspiration. Retrospective review. St. Louis Children's Hospital, a tertiary care center. Consecutive sample of 125 patients with esophageal or airway foreign bodies. Fifty percent of all patients had private health insurance. Fifty-six percent of all preschool patients and 20% of all school-age patients were uninsured (P < 0.01, Fisher's exact test). Eighty-five percent of patients with airway foreign bodies, and 84% of patients with esophageal foreign bodies were in the preschool group. Sixty-one percent of preschool patients and 21% of school-age patients with esophageal foreign bodies were uninsured (P < 0.05). Forty-six percent of preschool patients with food aspiration lacked health insurance (88% of these children were fed the aspirated item). No school-age group was available for comparison. Fifty percent of preschool children with aspiration of non food items were uninsured, as were 16% of their school-age counterparts. Insurance status must be considered as a risk factor for foreign body aspiration and ingestion. Preschool children are more likely to lack private health insurance than school-age children with the same diagnosis. In a majority of aspiration events, the child was being fed the inappropriate food item, perhaps indicating a lack of caretaker education and anticipatory guidance. A direct focus on 'passive protection', anticipatory guidance in clinics for all patients, and public education with emphasis on preventive care are proposed as means to decrease the incidence of airway and esophageal foreign bodies in children.

Amnioinfusion for the prevention of the meconium aspiration syndrome.

PubMed

Fraser, William D; Hofmeyr, Justus; Lede, Roberto; Faron, Gilles; Alexander, Sophie; Goffinet, François; Ohlsson, Arne; Goulet, Céline; Turcot-Lemay, Lucile; Prendiville, Walter; Marcoux, Sylvie; Laperrière, Louise; Roy, Chantal; Petrou, Stavros; Xu, Hai-Rong; Wei, Bin

2005-09-01

It is uncertain whether amnioinfusion (infusion of saline into the amniotic cavity) in women who have thick meconium staining of the amniotic fluid reduces the risk of perinatal death, moderate or severe meconium aspiration syndrome, or both. We performed a multicenter trial in which 1998 pregnant women in labor at 36 or more weeks of gestation who had thick meconium staining of the amniotic fluid were stratified according to the presence or absence of variable decelerations in fetal heart rate and then randomly assigned to amnioinfusion or to standard care. The composite primary outcome measure was perinatal death, moderate or severe meconium aspiration syndrome, or both. Perinatal death, moderate or severe meconium aspiration syndrome, or both occurred in 44 infants (4.5 percent) of women in the amnioinfusion group and 35 infants (3.5 percent) of women in the control group (relative risk, 1.26; 95 percent confidence interval, 0.82 to 1.95). Five perinatal deaths occurred in the amnioinfusion group and five in the control group. The rate of cesarean delivery was 31.8 percent in the amnioinfusion group and 29.0 percent in the control group (relative risk, 1.10; 95 percent confidence interval, 0.96 to 1.25). For women in labor who have thick meconium staining of the amniotic fluid, amnioinfusion did not reduce the risk of moderate or severe meconium aspiration syndrome, perinatal death, or other major maternal or neonatal disorders. Copyright 2005 Massachusetts Medical Society.

Validity of cervical auscultation in the screening for aspiration.

PubMed

Al Hawat, A; Woisard, V; Perez-Begout, L; Sarrabère, E; Grand, S; Puech, M

2014-01-01

Cervical auscultation could improve the performance of bedside swallowing test to predict aspiration, especially silent aspiration. The aim of this study is to compare the predictive values of bedside swallowing test performed with and without cervical auscultation by logopedist students who had intensive training on cervical auscultation. 64 patients were included in the study. They all underwent swallowing test alone, combined swallowing test and cervical auscultation, and videofluoroscopic swallowing study as defined gold standard. Two logopedist students, at the end of their training, performed the auscultation and noted their results. 128 tests were performed, 96% of the tests were judged positive for aspiration. When comparing the results of the two different clinical tests, the detection of clinical signs is not improved by the addition of auscultation. Using a penetration aspiration scale threshold >5, the area under the curve measured for the swallowing test alone was significantly higher than that measured for the combined tests (p = 0.03) (0.66 for the swallowing test alone (95% CI between 0.49 and 0.83), and 0.50 for the combined tests (95% CI between 0.31 and 0.69). This study showed no advantage in performing cervical auscultation with bedside swallowing test. Cervical auscultation seems to hamper the assessment, mainly the perception of wet voice and laryngeal motion. These results are compatible with literature but need further confirmation using studies performed with trained logopedists.

Predictive value of α-amylase in tracheal aspirates for ventilator-associated pneumonia in elderly patients.

PubMed

Qu, Ge-Ping; Fang, Xiang-Qun; Xu, Ya-Ping; Shi, Min; Wang, Yang; Gong, Mei-Liang; Fang, Hao-Ming

2018-04-01

This study aims to investigate the correlation between α-amylase in tracheal aspirates and risk factors of aspiration, as well as ventilator-associated pneumonia (VAP), in elderly patients undergoing mechanical ventilation and explore the clinical value of α-amylase for predicting VAP. Tracheal aspirates were collected from elderly patients within 2 weeks after tracheal intubation in mechanical ventilation, and α-amylase was detected. Patients were grouped according to the presence of VAP. The correlation between α-amylase and risk factors of aspiration before intubation, as well as VAP, were analyzed. The sample of this study comprised 147 patients. The average age of these patients was 86.9 years. The incidence of VAP was 21% during the study period. Tracheal aspirate α-amylase level increased with the increase in the number of risk factors for aspiration before intubation, α-amylase level was significantly higher in the VAP group than in the non-VAP group, the area under the receiver operating characteristic curve (ROC) of the diagnostic value of α-amylase for VAP was 0.813 (95% CI: 0.721-0.896), threshold value was 4,681.5 U/L, sensitivity was 0.801 and specificity was 0.793. Logistic multivariate analysis revealed the following risk factors for VAP: a number of risk factors before intubation of ≥3, a Glasgow score of <8 points, the absence of continuous aspiration of subglottic secretion and a tracheal aspirate α-amylase level of >4681.5 U/L. Tracheal aspirate α-amylase can serve as a biomarker for predicting VAP in elderly patients undergoing mechanical ventilation. © 2017 John Wiley & Sons Ltd.

Abnormal Uterine Bleeding- evaluation by Endometrial Aspiration.

PubMed

Singh, Pratibha

2018-01-01

Endometrial evaluation is generally indicated in cases presenting with abnormal uterine bleeding (AUB), especially in women more than 35 years of age. AUB encompasses a variety of presentation, for example, heavy menstrual bleeding, frequent bleeding, irregular vaginal bleeding, postcoital and postmenopausal bleeding to name a few. Many methods are used for the evaluation of such cases, with most common being sonography and endometrial biopsy with very few cases requiring more invasive approach like hysteroscopy. Endometrial aspiration is a simple and safe office procedure used for this purpose. We retrospectively analyzed cases of AUB where endometrial aspiration with Pipette (Medgyn) was done in outpatient department between January 2015 and April 2016. Case records (both paper and electronic) were used to retrieve data. One hundred and fifteen cases were included in the study after applying inclusion and exclusion criteria. Most cases were between 46 and 50 years of age followed by 41-45 years. No cases were below 25 or more than 65 years of age. Heavy menstrual bleeding was the most common presentation of AUB. Adequate samples were obtained in 86% of cases while 13.9% of cases' sample was inadequate for opinion, many of which were later underwent hysteroscopy and/or dilatation and curettage (D and C) in operation theater; atrophic endometrium was the most common cause for inadequate sample. Uterine malignancy was diagnosed in three cases. Endometrial aspiration has been compared with traditional D and C as well as postoperative histopathology in various studies with good results. Many such studies are done in India as well as in western countries confirming good correlation with histopathology and adequate tissue sample for the pathologist to give a confident diagnosis. No complication or side effect was noted with the use of this device. Endometrial aspiration is a simple, safe, and effective method to sample endometrium in cases of AUB avoiding risk of

21 CFR 884.1060 - Endometrial aspirator.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Endometrial aspirator. 884.1060 Section 884.1060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... endometrium, and (ii) Contraindications: Pregnancy, history of uterine perforation, or a recent cesarean...

21 CFR 884.1060 - Endometrial aspirator.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Endometrial aspirator. 884.1060 Section 884.1060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... endometrium, and (ii) Contraindications: Pregnancy, history of uterine perforation, or a recent cesarean...

21 CFR 884.1060 - Endometrial aspirator.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Endometrial aspirator. 884.1060 Section 884.1060 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... endometrium, and (ii) Contraindications: Pregnancy, history of uterine perforation, or a recent cesarean...

Career Aspirations and Expectations of College Students: Demographic and Labor Market Comparisons

ERIC Educational Resources Information Center

Metz, A. J.; Fouad, Nadya; Ihle-Helledy, Kris

2009-01-01

Replicating previous research, this study examined differences in 677 diverse college students' career aspirations and expectations based on gender and ethnicity, and compared their career expectations to the U.S. workforce. This study extended the literature base by exploring discrepancies between occupational aspirations and expectations…

Gene expression profiles in anatomically and functionally distinct regions of the normal aged human brain

PubMed Central

Liang, Winnie S.; Dunckley, Travis; Beach, Thomas G.; Grover, Andrew; Mastroeni, Diego; Walker, Douglas G.; Caselli, Richard J.; Kukull, Walter A.; McKeel, Daniel; Morris, John C.; Hulette, Christine; Schmechel, Donald; Alexander, Gene E.; Reiman, Eric M.; Rogers, Joseph; Stephan, Dietrich A.

2008-01-01

In this article, we have characterized and compared gene expression profiles from laser capture microdissected neurons in six functionally and anatomically distinct regions from clinically and histopathologically normal aged human brains. These regions, which are also known to be differentially vulnerable to the histopathological and metabolic features of Alzheimer’s disease (AD), include the entorhinal cortex and hippocampus (limbic and paralimbic areas vulnerable to early neurofibrillary tangle pathology in AD), posterior cingulate cortex (a paralimbic area vulnerable to early metabolic abnormalities in AD), temporal and prefrontal cortex (unimodal and heteromodal sensory association areas vulnerable to early neuritic plaque pathology in AD), and primary visual cortex (a primary sensory area relatively spared in early AD). These neuronal profiles will provide valuable reference information for future studies of the brain, in normal aging, AD and other neurological and psychiatric disorders. PMID:17077275

Secondary Voice Restoration After Laryngotracheal Separation (LTS) for Dysphagia with Intractable Aspiration.

PubMed

Bonte, Katrien; Huvenne, Wouter; De Loof, Marie; Deron, Philippe; Viaene, Annick; Duprez, Fréderic; Vermeersch, Hubert

2015-12-01

Intractable aspiration is a serious, often life-threatening condition due to its potential impact on pulmonary function. Aspiration requires therapeutic measures, starting with conservative management but often necessitating surgical treatment. The basic surgical principle is to separate the alimentary and respiratory tracts through a variety of procedures which, unfortunately, nearly all result in the loss of phonation, with the exception of total laryngectomy (TL) which includes the placement of an indwelling voice prosthesis. In this study, we present a modified laryngotracheal separation (LTS) technique that, we believe, offers multiple advantages compared to standard TL. After reviewing the medical records of 35 patients with intractable aspiration who have undergone LTS, we describe the surgical technique and present the postoperative result. In a second surgical procedure about two months following LTS, we aimed to achieve voice restoration by placement of an indwelling voice prosthesis. Intractable aspiration was successfully treated in all patients. Placement of an indwelling voice prosthesis during a second operation was successful in 15 patients, representing the largest reported cohort thus far. LTS is a reliable surgical technique to treat intractable aspiration, with restoration of oral intake, thereby improving the general condition and quality of life of these unfortunate patients. Furthermore, voice restoration can be achieved in selected patients, by placement of a voice prosthesis.

Aspiration cytology of mammary analogue secretory carcinoma of the salivary gland.

PubMed

Jung, Min Jung; Kim, Sang Yoon; Nam, Soon Yuhl; Roh, Jong-Lyel; Choi, Seung-Ho; Lee, Jeong Hyun; Baek, Jung Hwan; Cho, Kyung-Ja

2015-04-01

Aspiration cytologic findings of mammary analogue secretory carcinoma (MASC), a newly established salivary gland neoplasm defined by a t(12;15)(p13;q25) ETV6-NTRK3 translocation, are not fully characterized to date. We report cytologic descriptions of nine cases of molecularly confirmed MASC, including two with unusual findings. Aspiration smears from nine MASCs of the salivary glands were retrospectively reviewed and analyzed according to the cellular and structural features of the corresponding surgical specimens. Aspiration smears of MASC generally reflected the histologic diversity of the tumors. Among usual histologic findings, a micropapillary pattern was associated with a predominance of vacuolated individual cells on aspiration smears, a papillary-cystic pattern with a predominance of thin branching papillary structures, and a microcystic pattern with a predominance of irregular sheets of eosinophilic cells. There were two unusual cases, one with three-dimensional groups of high-grade atypical cells, and one with epithelial clusters floating in a notably mucinous background. These cases represented MASC with high-grade transformation and MASC with cystadenocarcinoma-like features, respectively. The secretory activity of MASC was not prominent in the aspiration specimens. Although unusual cases were present, most MASC cases showed characteristic cytologic findings, which could aid the cytologic diagnosis of MASC. And knowledge of the histologic spectrum of MASC, including high-grade transformation, could be valuable for cytological differential diagnoses of salivary gland tumors, and the management of patients with MASC. © 2014 Wiley Periodicals, Inc.

Massive aspiration past the tracheal tube cuff caused by closed tracheal suction system.

PubMed

Dave, Mital H; Frotzler, Angela; Madjdpour, Caveh; Koepfer, Nelly; Weiss, Markus

2011-01-01

Aspiration past the tracheal tube cuff has been recognized to be a risk factor for the development of ventilator-associated pneumonia (VAP). This study investigated the effect of closed tracheal suctioning on aspiration of fluid past the tracheal tube cuff in an in vitro benchtop model. High-volume low pressure tube cuffs of 7.5 mm internal diameter (ID) were placed in a 22 mm ID artificial trachea connected to a test lung. Positive pressure ventilation (PPV) with 15 cm H₂O peak inspiratory pressure and 5 cm H₂O positive end-expiratory pressure (PEEP) was used. A closed tracheal suction system (CTSS) catheter (size 14Fr) was attached to the tracheal tube and suction was performed for 5, 10, 15, or 20 seconds under 200 or 300 cm H₂O suction pressures. Amount of fluid (mL) aspirated along the tube cuff and the airway pressure changes were recorded for each suction procedure. Fluid aspiration during different suction conditions was compared using Kruskal-Wallis and Mann-Whitney test (Bonferroni correction [α = .01]). During 10, 15, and 20 seconds suction, airway pressure consistently dropped down to -8 to -13 cm H₂O (P < .001) from the preset level. Fluid aspiration was never observed under PPV + PEEP but occurred always during suctioning. Aspiration along the tube cuff was higher with -300 cm H₂O than with -200 cm H₂O suction pressure (P < .001) and was much more during 15 and 20 seconds suction time as compared to 5 seconds (P < .001). Massive aspiration of fluid occurs along the tracheal tube cuff during suction with the closed tracheal suction system. © SAGE Publications 2011.

Evaluation of hypopharyngeal suction to eliminate aspiration: the Retro-Esophageal Suction (REScue) catheter.

PubMed

Belafsky, Peter C; Mehdizadeh, O B; Ledgerwood, L; Kuhn, M

2015-02-01

Profound oropharyngeal dysphagia (OPD) is common and costly. Treatment options are limited. The purpose of this investigation was to evaluate the utility of hypopharyngeal suction at the upper esophageal sphincter (UES) to eliminate aspiration. Five different catheters were passed retrograde up the esophagus and positioned at the UES in a cadaver model of profound OPD. Suction was affixed to each catheter. 10 cc of barium was administered into the pyriform sinus, and videofluoroscopy was utilized to evaluate the presence of aspiration. 6 trials were administered per catheter and for a no catheter control. The outcome measures were the incidence of aspiration, the NIH Swallow Safety Scale (NIH-SSS), and UES opening. Control trials with no suction resulted in an aspiration rate of 100 % (6/6 trials). Negative pressure through 16, 18, 24, and 30 Fr catheter resulted in an aspiration rate of 0 % (0/24 trials; p < 0.001), and suction through a 12-Fr catheter resulted in an aspiration rate of 33 % (2/6 trials; p > 0.05). The mean NIH-SSS improved from 7.0 (±0.0) in the control to 0 (±0.0) with hypopharyngeal suction (18 Fr nasogastric catheter; p < 0.001). Mean UES opening improved from 0.0 (±0.0) mm in the control condition to 8.6 (±0.2) mm with a hypopharyngeal catheter (16 Fr Foley catheter; p < 0.001). Negative pressure applied through retro-esophageal suction catheters (>12 Fr) at the level of the UES reduced aspiration by 100 % and significantly increased UES opening in a cadaveric model of profound oropharyngeal dysphagia.

[Tracheobronchial lavage--a supplementary measure in the initial management of meconium aspiration syndrome].

PubMed

Rosegger, H; Engele, H; Haas, J

1987-12-18

Pulmonary lavage - a supplementary measure of resuscitation in newborn infants with severe aspiration of meconium stained amniotic fluid. During 1984-1985 150 mature newborn infants who had aspirated heavily-stained or pea soup-like amniotic fluid were resuscitated at the University Hospital of Obstetrics and Gynaecology in Graz. In 109 of these infants (controls) routine aspiration of both the upper and lower airways was accomplished as soon as possible, whilst in the remaining 41 infants (lavaged) pulmonary lavage with saline was additionally performed via an endotracheal tube after aspiration to clear the trachea and the upper bronchi from thick meconium which could not have been removed as efficiently otherwise. The incidence of manifest meconium aspiration syndrome was significantly higher (22%) in the lavaged infants than in the controls (8%). Mechanical ventilation was performed in 36% of the lavaged infants, whereas only 5.5% of the controls had to be ventilated for more than 1 hour. The mean duration of ventilation, however, was shorter (Mh = 5.1 hrs vs Mh = 69 hrs) and the average age at discharge lower in the lavaged. Three infants died, two of whom had severe malformations. Only one death in the lavaged infants was attributable to severe meconium aspiration syndrome already manifest at birth. Three infants (two lavaged, one control) showed radiological evidence of pneumothorax, but without clinical appearance of respiratory distress. Since the lavaged group naturally contained the more severely distressed infants, with a high incidence of caesarean section on account of intrauterine asphyxia and lower Apgar scores at one and five minutes, the high incidence of radiologically confirmed meconium aspiration syndrome was not surprising.(ABSTRACT TRUNCATED AT 250 WORDS)

The cytomorphologic spectrum of Wilms tumour on fine needle aspiration: a single institutional experience of 110 cases.

PubMed

Nayak, A; Iyer, V K; Agarwala, S

2011-02-01

To analyse the cytomorphologic spectrum of Wilms tumour (WT) on aspirates, the largest series reported to date. Adequate aspirates from paediatric renal tumours over a period of 17 years were reviewed and selected if subsequent excision showed WT or aspirates were diagnostic for WT and clinical/radiological evidence consistent with that diagnosis. Smears were re-examined for the proportion of components, degree of pleomorphism and mitosis. Of 110 aspirates, smears were triphasic in 44 (40.0%), biphasic (blastema and tubules) in 36 (32.7%) and monophasic (blastema alone) in 30 (27.3%). Stromal predominance was seen in 11 aspirates (10.0%) and five showed rhabdomyoblastic differentiation; all 11 were triphasic. Mean mitotic rate was 9.3/5000 cells (range 4-39/5000). Nuclear atypia not amounting to anaplasia and without atypical mitoses was seen in 15 (13.6%); these presented diagnostic problems. Two aspirates (1.8%) were considered anaplastic (unfavourable), both having atypical mitoses. Criteria similar to histology (i.e. 3-fold or more variation in nuclear size, marked hyperchromasia with bizarre nuclei and atypical mitoses in a biphasic or triphasic aspirate) helped in distinguishing anaplastic WT. Histopathological correlation in 67 cases showed good correlation of blastemal predominance, stromal predominance and anaplastic histology with the corresponding cytology. However, 9/27 (33.3%) triphasic tumours had only blastemal cells on corresponding aspiration because of sampling error. Cytokeratin was positive in 4 of 20 aspirates with blastema alone. Aspirates from WT were triphasic or biphasic in the majority (72.7%), permitting cytological diagnosis, which was improved by cytokeratin immunocytochemistry. Blastemal and stromal predominance on histology correlated well with cytology, but many triphasic tumours showed only blastema on aspiration. Anaplastic WT can be detected on aspirates using criteria similar to histology. © 2010 Blackwell Publishing Ltd.

[Recommendations for the prevention of organic foreign bodies aspiration].

PubMed

Rodríguez, Hugo; Cuestas, Giselle; Gregori, Darío; Lorenzoni, Giulia; Tortosa, Susana; Rodríguez D'Aquila, Máximo; Rodríguez D'Aquila, Juan A; Carrera, Sandra; Passali, Desiderio

2017-10-01

Foreign body aspiration remains a common and potentially serious pediatric problem. Most aspirated foreign bodies are food. The education of parents and caregivers about choking hazards and how to avoid them is critical to reduce the incidence of these events. The pediatricians play a key role in promoting injury prevention. We indicate the main characteristics of hazardous food and we present recommendations on age-appropriate meals, adequate forms of food preparation and behavioral rules at mealtimes in order to reduce food choking. Sociedad Argentina de Pediatría.

The Role of Relative Intrinsic Aspirations in Chinese Adolescents' Prosocial Behaviors

ERIC Educational Resources Information Center

Fu, Xinyuan; Liu, Xiaolan; Yang, Ying; Zhang, Mengyuan; Kou, Yu

2018-01-01

We examined Chinese adolescents' aspirations and explored the relationship between relative intrinsic aspirations (RIA) and prosocial behaviors and whether adolescents with different levels of RIA have different emphases on self- and other-oriented considerations during prosocial decision making. In Study 1, 236 participants were recruited and…

A Longitudinal Study of Occupational Aspirations and Attainments of Iowa Young Adults.

ERIC Educational Resources Information Center

Yoesting, Dean R.; And Others

The causal linkage between socioeconomic status, occupational and educational aspiration, and attainment was examined in this attempt to test an existing theoretical model which used socioeconomic status as a major input variable, with significant other influence as a crucial intervening variable between socioeconomic status and aspiration. The…

Aspiration and tetracycline sclerotherapy of hydrocele.

PubMed

Fuse, H; Nishikawa, Y; Shimazaki, J; Katayama, T

1991-01-01

Seventeen patients with hydrocele of the testis were treated by aspiration of fluid and substitution with tetracycline supplemented with 1% lidocaine. In 15 patients (88%) symptoms disappeared by sclerotherapy. After sclerotherapy scrotal ultrasonography was useful to diagnose either relapse or thickened tunica vaginalis. No side effect was noticed.

Movement control during aspiration with different injection systems via video monitoring-an in vitro model.

PubMed

Kämmerer, P W; Schneider, D; Pacyna, A A; Daubländer, M

2017-01-01

The aim of the present study was an evaluation of movement during double aspiration by different manual syringes and one computer-controlled local anesthesia delivery system (C-CLAD). With five different devices (two disposable syringes (2, 5 ml), two aspirating syringes (active, passive), one C-CLAD), simulation of double aspiration in a phantom model was conducted. Two experienced and two inexperienced test persons carried out double aspiration with the injection systems at the right and left phantom mandibles in three different inclination angles (n = 24 × 5 × 2 for each system). 3D divergences of the needle between aspiration procedures (mm) were measured with two video cameras. An average movement for the 2-ml disposal syringe of 2.85 mm (SD 1.63), for the 5 ml syringe of 2.36 mm (SD 0.86), for the active-aspirating syringe of 2.45 mm (SD 0.9), for the passive-aspirating syringe of 2.01 mm (SD 0.7), and for the C-CLAD, an average movement of 0.91 mm (SD 0.63) was seen. The movement was significantly less for the C-CLAD compared to the other systems (p < 0.001). The movement of the needle in the soft tissue was significantly less for the C-CLAD compared to the other systems (p < 0.001). A difference in involuntary movement of the syringe could be seen in comparison between manual and C-CLAD systems. Launching the aspiration by a foot pedal in computer-assisted anesthesia leads to a minor movement. To solve the problem of movement during aspiration with possibly increased false-negative results, a C-CLAD seems to be favorable.

Longitudinal evaluation of immunohistochemical findings of milk aspiration: an experimental study using a murine model.

PubMed

Nagai, Tomonori; Aoyagi, Miwako; Ochiai, Eriko; Sakai, Kentaro; Maruyama-Maebashi, Kyoko; Fukui, Kenji; Iwadate, Kimiharu

2011-06-15

To examine the longitudinal change of pathological findings of the lung and other organs in milk aspiration, an experimental study using a murine model was carried out. Either 0.5 or 1.0 ml cow's milk was instilled into the trachea of rats. From immediately after to 14 days after instillation, the animals were sacrificed, and the lungs, liver, kidneys, and spleen were removed. The results of immunostaining with anti-human α lactalbumin antibody indicated that not only the lung but also the kidney and spleen showed a positive reaction against the antibody over time. Experimentally aspirated milk was detectable in alveoli until 2 days after instillation. It was also detectable in renal tubules from 1 to 6h after instillation. Macrophages containing granules of aspirated milk were observed in splenic red pulp from 3h to 14 days after instillation. Detection of aspirated milk in other organs except the lung would be clear evidence of intravital milk aspiration and would suggest previous or recurrent milk aspiration. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Foreign body aspiration in adult airways: therapeutic approach

PubMed Central

Hewlett, Justin C.; Rickman, Otis B.; Lentz, Robert J.; Prakash, Udaya B.

2017-01-01

Tracheobronchial foreign body (FB) aspiration is an uncommon but potentially life-threatening event in adults. Symptoms typically consist of a choking event followed by cough and dyspnea, however, these findings are inconsistent and symptoms may mimic more chronic lung diseases such as asthma or chronic obstructive pulmonary disease. Chest radiography and computed tomography can provide information regarding the location and characteristics of foreign bodies and aid in diagnosis. Bronchoscopy remains the gold standard for diagnosis and management of FB aspiration. The authors describe the typical clinical presentation, diagnostic evaluation, and bronchoscopic management of foreign bodies in adult airways with a focus on bronchoscopic techniques and potential complications of FB extraction. PMID:29221325

Pepsin as a Marker for Pulmonary Aspiration

PubMed Central

Metheny, Norma A.; Chang, Yie-Hwa; Ye, Jing Song; Edwards, Sharon J.; Defer, Julie; Dahms, Thomas E.; Stewart, Barbara J.; Stone, Kathleen S.; Clouse, Ray E.

2008-01-01

BACKGROUND Although assessment for aspiration of small volumes of gastric contents in tube-fed patients receiving mechanical ventilation is important, available methods for this purpose are not wholly satisfactory. A potential method is immunoassay of tracheal secretions for the gastric enzyme pepsin. OBJECTIVES To determine the frequency with which pepsin in suctioned tracheal secretions from acutely ill, tube-fed patients receiving mechanical ventilation could be detected via an immunoassay. METHODS A convenience sample of 136 specimens of suctioned tracheal secretions was collected from 30 acutely ill, tube-fed adults receiving mechanical ventilation. Multiple samples were obtained from 26 of the 30 patients (range, 2−11 per subject). An immunoassay with rooster polyclonal antibodies to purified human pepsin was used to detect pepsin in the secretions. RESULTS Fourteen specimens tested positive for pepsin. Secretions from 5 patients accounted for the 14 pepsin-positive results. A significant relationship was found between the position of the head of the bed and the presence of pepsin in tracheal secretions (P< .001). Of the 14 pepsin-positive specimens, 13 (92.9%) were obtained from subjects in a flat position. CONCLUSIONS A pepsin immunoassay can be used to detect pepsin in human tracheal secretions. If pepsin in tracheal secretions is considered an indicator of aspiration of gastric contents, aspiration occurred in 5 of the 30 subjects. A flat position is strongly associated with the presence of pepsin in tracheal secretions. PMID:11888127

The value of oropharyngoesophageal scintigraphy in the management of aspiration into the tracheobronchial tree in neurological patients.

PubMed

Grosso, M; Fattori, B; Volterrani, D; Chondrogiannis, S; Boni, G; Nacci, A; Marzola, M C; Rubello, D

2015-01-01

Dysphagia and bolus aspiration are two of the most frequent and invalidating symptoms of various neurological diseases. Swallowing disorders often lead to tracheobronchial aspiration with consequent pneumonia episodes. Aspiration pneumonia per se constitutes the most frequent cause of death in these patients, with mortality rate ranging from 20% to 62%. Oropharyngoesophageal scintigraphy (OPES) permits functional quantitative assessment of the different stages of swallowing, together with the detection and quantitative measurement of bolus aspiration. In this work, we analyzed the role of OPES in patients with different neurological conditions to evaluate swallowing and to detect and quantify bolus aspiration. We enrolled 43 neurological patients (25 women and 18 men, mean age 67.3±12.4 yr) complaining of dysphagia with suspected inhalation. All patients underwent OPES with (99m)Tc-nanocolloid using a liquid bolus first, followed by a semi-solid bolus. We evaluated the following parameters: Oral, Pharyngeal and Esophageal Transit Time, Oro-Pharyngeal Retention Index, Esophageal Emptying Rate, and Aspiration Rate (% AR). OPES detected some airway aspiration in 26/43 patients. 19 patients had tracheal aspiration (with a mean 18.1% AR) and the remaining 7 patients had bilateral broncho-pulmonary aspiration (mean 44.9% AR). OPES is a feasible, repeatable and noninvasive method that allows quantitative assessment of bolus aspiration into the tracheobronchial tract, thus representing a useful and accurate tool to guide the most appropriate treatment and to monitor response to therapy in neurological patients with dysphagia. Copyright © 2015 Elsevier España, S.L.U. and SEMNIM. All rights reserved.

Aging-Related Geniohyoid Muscle Atrophy Is Related to Aspiration Status in Healthy Older Adults

PubMed Central

2013-01-01

Background. Age-related muscle weakness due to atrophy and fatty infiltration in orofacial muscles may be related to swallowing deficits in older adults. An important component of safe swallowing is the geniohyoid (GH) muscle, which helps elevate and stabilize the hyoid bone, thus protecting the airway. This study aimed to explore whether aging and aspiration in older adults were related to GH muscle atrophy and fatty infiltration. Method. Eighty computed tomography scans of the head and neck from 40 healthy older (average age 78 years) and 40 younger adults (average age 32 years) were analyzed. Twenty aspirators and 20 nonaspirators from the 40 older adults had been identified previously. Two-dimensional views in the sagittal and coronal planes were used to measure the GH cross-sectional area and fatty infiltration. Results. GH cross-sectional area was larger in men than in women (p < .05). Decreased cross-sectional area was associated with aging (p < .05), and cross-sectional area was significantly smaller in aspirators compared with nonaspirators, but only among the older men (p < .01). Increasing fatty infiltration was associated with aging in the middle (p < .05) and posterior (p < .01) portions of the GH muscle. There was no significant difference in fatty infiltration of the GH muscle among aspirators and nonaspirators. Conclusion. GH muscle atrophy was associated with aging and aspiration. Fatty infiltration in the GH muscle was increased with aging but not related to aspiration status. These findings suggest that GH muscle atrophy may be a component of decreased swallowing safety and aspiration in older adults and warrants further investigation. PMID:23112114

Defining the Pathophysiological Role of Tau in Experimental TBI

DTIC Science & Technology

2017-10-01

clinically a blood test for improving the diagnosis of TBI-induced chronic neurodegenerative disease in the long-term post -injury time period. The...we will complete the quantitative analysis of perforant pathway synapse integrity in all 63 long-term post -injury cases. Our results thus far support...substantiated by quantitative analysis of NeuN-positive neuronal density in lateral entorhinal cortex layer II at 4 months post -injury (Table 1). At

Another Opinion No Inspiration, No Aspirations

ERIC Educational Resources Information Center

Brown, Donna W.

2004-01-01

School library media specialists are the first to witness the malaise that permeates American schools threatening the future of our society. Believing that personal lack of aspirations, our failure to encourage reading for pure enjoyment, and society's disrespect toward education has left a void in our children that is filled with apathy.

Ovum pick-up in sheep: a comparison between different aspiration devices for optimal oocyte retrieval.

PubMed

Rodríguez, C; Anel, L; Alvarez, M; Anel, E; Boixo, J C; Chamorro, C A; de Paz, P

2006-04-01

In vivo ovum pick-up (OPU) in sheep may be improved with a proper choice of aspiration elements (needle and tubing) and aspiration vacuum pressure. In the present study, two experiments were carried out. In Expt 1, visible follicles in ovaries of slaughtered ewes (treated separately according to their diameters: small<3 mm, medium 3-5 mm and large>5 mm) were aspirated using different combinations of the three studied factors such as aspiration flow rate (10, 20, 30, 40 and 50 ml water/min), needle gauge (18 and 20 G) and tubing inner diameter (1, 2 or 3 mm internal diameter). In Expt 2, a study with two 18 G needles of different lengths (18 G: 82 mm; 18 GL: 600 mm) was carried out, using ovaries obtained post-mortem, and performing in vivo laparoscopic follicular aspiration on ewes. We considered good quality oocytes as those with both complete compact cumulus and a homogeneous cytoplasm. Recovery rate, proportion of good quality oocytes (good quality oocytes/100 oocytes recovered) and overall efficiency (good quality oocytes/100 follicles aspirated) were noted. In Expt 1, aspiration flow rate affect remarkable proportion of good quality oocytes (69.5%, 50.5%, 44.8%, 36.5% and 28.3% for flows from 10 to 50 ml/min respectively, p<0.05). Needle gauge did not affect aspiration device efficiency. Thin and intermediate tubings were more effective (overall efficiency rates: 34.9%, 32.3% and 28.1% for 1, 2 and 3 mm respectively, p<0.05). Follicle size did not affect recovery rate, but proportion of good quality oocytes was higher for large (77.9%) and medium (64.4%) follicles (p<0.05). Finally, some combinations of the aspiration device showed greater effectiveness. In Expt 2, needle length did not influence recovery rate, but good quality oocytes rate was significantly modified both post-mortem and in vivo (good quality rate for 18 G vs 18 GL needles: 69.5% vs 47.7% and 58.1% vs 25.4%, post-mortem and in vivo respectively, p<0.05). We conclude that low-aspiration flow

Bronchoscopic and histological changes over time following acute ferrous sulphate tablet aspiration

PubMed Central

Maw, Matthew; Chiu, Robert; Lim, Albert Yick Hou

2012-01-01

An 84-year-old woman accidentally aspirated an iron tablet. She was successfully treated with early endobronchial removal of the iron tablet remnants, oral corticosteroids and antibiotics. We describe the bronchoscopic and histological changes over time following acute iron tablet aspiration and highlight the importance of early intervention to avoid complications. PMID:23257641

Considering the Influence of High School Experiences on Students' College Aspirations

ERIC Educational Resources Information Center

Trolian, Teniell Leigh

2016-01-01

This study considered whether participation in several out-of-class experiences during high school influenced the odds that a student will aspire to earn at least a Bachelor's degree. Additionally, this study considered whether these experiences, considered together, had a cumulative effect on the odds that a student will aspire to earn at least a…

Understanding Mentoring in Leadership Development: Perspectives of District Administrators and Aspiring Leaders

ERIC Educational Resources Information Center

Clayton, Jennifer K.; Sanzo, Karen L.; Myran, Steve

2013-01-01

According to Daresh, collaboration between veteran and new or aspiring leaders can promote an environment that is conducive to high levels of student achievement. This study sought to understand the mentoring relationship between veteran school leaders and aspiring leaders within a district that is in Year 2 of a School Leadership Program grant.…

The Trouble with Doctoral Aspiration Now

ERIC Educational Resources Information Center

Burford, James

2018-01-01

This article attends to the affective-political dimensions of doctoral aspiration. It considers why doctoral students continue to hope for an 'academic good life' in spite of the depressed and precarious features of the academic present. The article emerges from 2013 research with ten doctoral students in the Arts and Social Sciences, at a…

Prognostic implications of aspiration pneumonia in patients with community acquired pneumonia: A systematic review with meta-analysis

PubMed Central

Komiya, Kosaku; Rubin, Bruce K.; Kadota, Jun-ichi; Mukae, Hiroshi; Akaba, Tomohiro; Moro, Hiroshi; Aoki, Nobumasa; Tsukada, Hiroki; Noguchi, Shingo; Shime, Nobuaki; Takahashi, Osamu; Kohno, Shigeru

2016-01-01

Aspiration pneumonia is thought to be associated with a poor outcome in patients with community acquired pneumonia (CAP). However, there has been no systematic review regarding the impact of aspiration pneumonia on the outcomes in patients with CAP. This review was conducted using the MOOSE guidelines: Patients: patients defined CAP. Exposure: aspiration pneumonia defined as pneumonia in patients who have aspiration risk. Comparison: confirmed pneumonia in patients who were not considered to be at high risk for oral aspiration. Outcomes: mortality, hospital readmission or recurrent pneumonia. Three investigators independently identified published cohort studies from PubMed, CENTRAL database, and EMBASE. Nineteen studies were included for this systematic review. Aspiration pneumonia increased in-hospital mortality (relative risk, 3.62; 95% CI, 2.65–4.96; P < 0.001, seven studies) and 30-day mortality (3.57; 2.18–5.86; P < 0.001, five studies). In contrast, aspiration pneumonia was associated with decreased ICU mortality (relative risk, 0.40; 95% CI, 0.26–0.60; P < 0.00001, four studies). Although there are insufficient data to perform a meta-analysis on long-term mortality, recurrent pneumonia, and hospital readmission, the few reported studies suggest that aspiration pneumonia is also associated with these poor outcomes. In conclusion, aspiration pneumonia was associated with both higher in-hospital and 30-day mortality in patients with CAP outside ICU settings. PMID:27924871