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Sample records for entorhinal cortex aspiration

  1. Functional subregions of the human entorhinal cortex

    PubMed Central

    Maass, Anne; Berron, David; Libby, Laura A; Ranganath, Charan; Düzel, Emrah

    2015-01-01

    The entorhinal cortex (EC) is the primary site of interactions between the neocortex and hippocampus. Studies in rodents and nonhuman primates suggest that EC can be divided into subregions that connect differentially with perirhinal cortex (PRC) vs parahippocampal cortex (PHC) and with hippocampal subfields along the proximo-distal axis. Here, we used high-resolution functional magnetic resonance imaging at 7 Tesla to identify functional subdivisions of the human EC. In two independent datasets, PRC showed preferential intrinsic functional connectivity with anterior-lateral EC and PHC with posterior-medial EC. These EC subregions, in turn, exhibited differential connectivity with proximal and distal subiculum. In contrast, connectivity of PRC and PHC with subiculum followed not only a proximal-distal but also an anterior-posterior gradient. Our data provide the first evidence that the human EC can be divided into functional subdivisions whose functional connectivity closely parallels the known anatomical connectivity patterns of the rodent and nonhuman primate EC. DOI: http://dx.doi.org/10.7554/eLife.06426.001 PMID:26052749

  2. Cellular properties of principal neurons in the rat entorhinal cortex. II. The medial entorhinal cortex.

    PubMed

    Canto, Cathrin B; Witter, Menno P

    2012-06-01

    Principal neurons in different medial entorhinal cortex (MEC) layers show variations in spatial modulation that stabilize between 15 and 30 days postnatally. These in vivo variations are likely due to differences in intrinsic membrane properties and integrative capacities of neurons. The latter depends on inputs and thus potentially on the morphology of principal neurons. In this comprehensive study, we systematically compared the morphological and physiological characteristics of principal neurons in all MEC layers of newborn rats before and after weaning. We recorded simultaneously from up to four post-hoc morphologically identified MEC principal neurons in vitro. Neurons in L(ayer) I-LIII have dendritic and axonal arbors mainly in superficial layers, and LVI neurons mainly in deep layers. The dendritic and axonal trees of part of LV neurons diverge throughout all layers. Physiological properties of principal neurons differ between layers. In LII, most neurons have a prominent sag potential, resonance and membrane oscillations. Neurons in LIII and LVI fire relatively regular, and lack sag potentials and membrane oscillations. LV neurons show the most prominent spike-frequency adaptation and highest input resistance. The data indicate that adult-like principal neuron types can be differentiated early on during postnatal development. The results of the accompanying paper, in which principal neurons in the lateral entorhinal cortex (LEC) were described (Canto and Witter,2011), revealed that significant differences between LEC and MEC exist mainly in LII neurons. We therefore systematically analyzed changes in LII biophysical properties along the mediolateral axis of MEC and LEC. There is a gradient in properties typical for MEC LII neurons. These properties are most pronounced in medially located neurons and become less apparent in more laterally positioned ones. This gradient continues into LEC, such that in LEC medially positioned neurons share some properties

  3. Structural development and dorsoventral maturation of the medial entorhinal cortex.

    PubMed

    Ray, Saikat; Brecht, Michael

    2016-04-02

    We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin - a marker of immature neurons - suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits - representing larger spatial-scales - follows later around the onset of exploratory behavior.

  4. Structural development and dorsoventral maturation of the medial entorhinal cortex

    PubMed Central

    Ray, Saikat; Brecht, Michael

    2016-01-01

    We investigated the structural development of superficial-layers of medial entorhinal cortex and parasubiculum in rats. The grid-layout and cholinergic-innervation of calbindin-positive pyramidal-cells in layer-2 emerged around birth while reelin-positive stellate-cells were scattered throughout development. Layer-3 and parasubiculum neurons had a transient calbindin-expression, which declined with age. Early postnatally, layer-2 pyramidal but not stellate-cells co-localized with doublecortin – a marker of immature neurons – suggesting delayed functional-maturation of pyramidal-cells. Three observations indicated a dorsal-to-ventral maturation of entorhinal cortex and parasubiculum: (i) calbindin-expression in layer-3 neurons decreased progressively from dorsal-to-ventral, (ii) doublecortin in layer-2 calbindin-positive-patches disappeared dorsally before ventrally, and (iii) wolframin-expression emerged earlier in dorsal than ventral parasubiculum. The early appearance of calbindin-pyramidal-grid-organization in layer-2 suggests that this pattern is instructed by genetic information rather than experience. Superficial-layer-microcircuits mature earlier in dorsal entorhinal cortex, where small spatial-scales are represented. Maturation of ventral-entorhinal-microcircuits – representing larger spatial-scales – follows later around the onset of exploratory behavior. DOI: http://dx.doi.org/10.7554/eLife.13343.001 PMID:27036175

  5. Effects of acetylcholine on neuronal properties in entorhinal cortex

    PubMed Central

    Heys, James G.; Schultheiss, Nathan W.; Shay, Christopher F.; Tsuno, Yusuke; Hasselmo, Michael E.

    2012-01-01

    The entorhinal cortex (EC) receives prominent cholinergic innervation from the medial septum and the vertical limb of the diagonal band of Broca (MSDB). To understand how cholinergic neurotransmission can modulate behavior, research has been directed toward identification of the specific cellular mechanisms in EC that can be modulated through cholinergic activity. This review focuses on intrinsic cellular properties of neurons in EC that may underlie functions such as working memory, spatial processing, and episodic memory. In particular, the study of stellate cells (SCs) in medial entorhinal has resulted in discovery of correlations between physiological properties of these neurons and properties of the unique spatial representation that is demonstrated through unit recordings of neurons in medial entorhinal cortex (mEC) from awake-behaving animals. A separate line of investigation has demonstrated persistent firing behavior among neurons in EC that is enhanced by cholinergic activity and could underlie working memory. There is also evidence that acetylcholine plays a role in modulation of synaptic transmission that could also enhance mnemonic function in EC. Finally, the local circuits of EC demonstrate a variety of interneuron physiology, which is also subject to cholinergic modulation. Together these effects alter the dynamics of EC to underlie the functional role of acetylcholine in memory. PMID:22837741

  6. Entorhinal cortex stimulation modulates amygdala and piriform cortex responses to olfactory bulb inputs in the rat.

    PubMed

    Mouly, A-M; Di Scala, G

    2006-01-01

    The rodent olfactory bulb sends direct projections to the piriform cortex and to two structures intimately implicated in memory processes, the entorhinal cortex and the amygdala. The piriform cortex has monosynaptic projections with the amygdala and the piriform cortex and is therefore in a position to modulate olfactory input either directly in the piriform cortex, or via the amygdala. In order to investigate this hypothesis, field potential signals induced in anesthetized rats by electrical stimulation of the olfactory bulb or the entorhinal cortex were recorded simultaneously in the piriform cortex (anterior part and posterior part) and the amygdala (basolateral nucleus and cortical nucleus). Single-site paired-pulse stimulation was used to assess the time courses of short-term inhibition and facilitation in each recording site in response to electrical stimulation of the olfactory bulb and entorhinal cortex. Paired-pulse stimulation of the olfactory bulb induced homosynaptic inhibition for short interpulse interpulse intervals (20-30 ms) in all the recording sites, with a significantly lower degree of inhibition in the anterior piriform cortex than in the other structures. At longer intervals (40-80 ms), paired-pulse facilitation was observed in all the structures. Paired-pulse stimulation of the entorhinal cortex mainly resulted in inhibition for the shortest interval duration (20 ms) in anterior piriform cortex, posterior piriform cortex and amygdala basolateral but not cortical nucleus. Double-site paired-pulse stimulation was then applied to determine if stimulation of the entorhinal cortex can modulate responses to olfactory bulb stimulation. For short interpulse intervals (20 ms) heterosynaptic inhibition was observed in anterior piriform cortex, posterior piriform cortex and amygdala basolateral but not cortical nucleus. The level of inhibition was greater in the basolateral nucleus than in the other structures. Taken together these data suggest that the

  7. Selective Vulnerability of Neurons in Layer II of the Entorhinal Cortex during Aging and Alzheimer's Disease

    PubMed Central

    Stranahan, Alexis M.; Mattson, Mark P.

    2010-01-01

    All neurons are not created equal. Certain cell populations in specific brain regions are more susceptible to age-related changes that initiate regional and system-level dysfunction. In this respect, neurons in layer II of the entorhinal cortex are selectively vulnerable in aging and Alzheimer's disease (AD). This paper will cover several hypotheses that attempt to account for age-related alterations among this cell population. We consider whether specific developmental, anatomical, or biochemical features of neurons in layer II of the entorhinal cortex contribute to their particular sensitivity to aging and AD. The entorhinal cortex is a functionally heterogeneous environment, and we will also review data suggesting that, within the entorhinal cortex, there is subregional specificity for molecular alterations that may initiate cognitive decline. Taken together, the existing data point to a regional cascade in which entorhinal cortical alterations directly contribute to downstream changes in its primary afferent region, the hippocampus. PMID:21331296

  8. Cholecystokinin from the entorhinal cortex enables neural plasticity in the auditory cortex.

    PubMed

    Li, Xiao; Yu, Kai; Zhang, Zicong; Sun, Wenjian; Yang, Zhou; Feng, Jingyu; Chen, Xi; Liu, Chun-Hua; Wang, Haitao; Guo, Yi Ping; He, Jufang

    2014-03-01

    Patients with damage to the medial temporal lobe show deficits in forming new declarative memories but can still recall older memories, suggesting that the medial temporal lobe is necessary for encoding memories in the neocortex. Here, we found that cortical projection neurons in the perirhinal and entorhinal cortices were mostly immunopositive for cholecystokinin (CCK). Local infusion of CCK in the auditory cortex of anesthetized rats induced plastic changes that enabled cortical neurons to potentiate their responses or to start responding to an auditory stimulus that was paired with a tone that robustly triggered action potentials. CCK infusion also enabled auditory neurons to start responding to a light stimulus that was paired with a noise burst. In vivo intracellular recordings in the auditory cortex showed that synaptic strength was potentiated after two pairings of presynaptic and postsynaptic activity in the presence of CCK. Infusion of a CCKB antagonist in the auditory cortex prevented the formation of a visuo-auditory association in awake rats. Finally, activation of the entorhinal cortex potentiated neuronal responses in the auditory cortex, which was suppressed by infusion of a CCKB antagonist. Together, these findings suggest that the medial temporal lobe influences neocortical plasticity via CCK-positive cortical projection neurons in the entorhinal cortex.

  9. Postnatal development of calcium-binding proteins immunoreactivity (parvalbumin, calbindin, calretinin) in the human entorhinal cortex.

    PubMed

    Grateron, L; Cebada-Sanchez, S; Marcos, P; Mohedano-Moriano, A; Insausti, A M; Muñoz, M; Arroyo-Jimenez, M M; Martinez-Marcos, A; Artacho-Perula, E; Blaizot, X; Insausti, R

    2003-12-01

    The entorhinal cortex is an essential component in the organization of the human hippocampal formation related to cortical activity. It transfers, neocortical information (ultimately distributed to the dentate gyrus and hippocampus) and receives most of the hippocampal output directed to neocortex. At birth, the human entorhinal cortex presents similar layer organization as in adults, although layer II (cell islands) and upper layer III have a protracted maturation. The presence of interneurons expressing calcium-binding proteins (parvalbumin, calbindin-D28K (calbindin) and calretinin) is well documented in the adult human entorhinal cortex. In many of them the calcium binding is co-localized with GABA. Parvalbumin-immunoreactive cells and fibers were virtually absent at birth, their presence increasing gradually in deep layer III, mostly in the lateral and caudal portions of the entorhinal cortex from the 5th month onwards. Calbindin immunoreactive cells and fibers were present at birth, mainly in layers II and upper III; mostly at rostral and lateral portions of the entorhinal cortex, increasing in number and extending to deep layers from the 5th month onwards. Calretinin immunoreactivity was present at birth, homogeneously distributed over layers I, II and upper V, throughout the entorhinal cortex. A substantial increase in the number of calretinin neurons in layer V was observed at the 5th month. The postnatal development of parvalbumin, calbindin and calretinin may have an important role in the functional maturation of the entorhinal cortex through the control of hippocampal, cortical and subcortical information.

  10. The piriform, perirhinal, and entorhinal cortex in seizure generation.

    PubMed

    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.

  11. Age effects on atrophy rates of entorhinal cortex and hippocampus

    PubMed Central

    Du, An-Tao; Schuff, Norbert; Chao, Linda L.; Kornak, John; Jagust, William J.; Kramer, Joel H.; Reed, Bruce R.; Miller, Bruce L.; Norman, David; Chui, Helena C.; Weiner, Michael W.

    2007-01-01

    The effects of age, subcortical vascular disease, apolipoprotein E (APOE) ɛ4 allele and hypertension on entorhinal cortex (ERC) and hippocampal atrophy rates were explored in a longitudinal MRI study with 42 cognitively normal (CN) elderly subjects from 58 to 87 years old. The volumes of the ERC, hippocampus, and white matter hyperintensities (WMH) and the presence of lacunes were assessed on MR images. Age was significantly associated with increased atrophy rates of 0.04 ± 0.02% per year for ERC and 0.05 ± 0.02% per year for hippocampus. Atrophy rates of hippocampus, but not that of ERC increased with presence of lacunes, in addition to age. WMH, APOE ɛ4 and hypertension had no significant effect on atrophy rates. In conclusion, age and presence of lacunes should be taken into consideration in imaging studies of CN subjects and AD patients to predict AD progression and assess the response to treatment trials. PMID:15961190

  12. The role of the entorhinal cortex in extinction: influences of aging.

    PubMed

    Bevilaqua, Lia R M; Rossato, Janine I; Bonini, Juliana S; Myskiw, Jociane C; Clarke, Julia R; Monteiro, Siomara; Lima, Ramón H; Medina, Jorge H; Cammarota, Martín; Izquierdo, Iván

    2008-01-01

    The entorhinal cortex is perhaps the area of the brain in which neurofibrillary tangles and amyloid plaques are first detectable in old age with or without mild cognitive impairment, and very particularly in Alzheimer's disease. It plays a key role in memory formation, retrieval, and extinction, as part of circuits that include the hippocampus, the amygdaloid nucleus, and several regions of the neocortex, in particular of the prefrontal cortex. Lesions or biochemical impairments of the entorhinal cortex hinder extinction. Microinfusion experiments have shown that glutamate NMDA receptors, calcium and calmodulin-dependent protein kinase II, and protein synthesis in the entorhinal cortex are involved in and required for extinction. Aging also hinders extinction; it is possible that its effect may be in part mediated by the entorhinal cortex.

  13. Effects of pre- or post-training entorhinal cortex AP5 injection on fear conditioning.

    PubMed

    Schenberg, Eduardo Ekman; Soares, Juliana Carlota Kramer; Oliveira, Maria Gabriela Menezes

    2005-11-15

    Fear conditioning is one of the most studied paradigms to assess the neural basis of emotional memory. The circuitry involves NMDA receptor activation in the amygdala and, in the case of contextual conditioning, in the hippocampus. Entorhinal cortex is one of the major input/output structures to the hippocampus and also projects to the amygdala, both through glutamatergic transmission. Other learning tasks involving hippocampus and amygdala, such as inhibitory avoidance, require entorhinal cortex during acquisition and consolidation. However, the involvement of NMDA receptors mediated transmission in entorhinal cortex in fear conditioning acquisition and consolidation is not clear. To investigate that issue, rats were trained in fear conditioning to both contextual and tone conditioned stimulus. Immediately before, immediately, 30 or 90 min after training they received NMDA antagonist AP5 or saline injections bilaterally in the entorhinal cortex (AP-6.8 mm, L +/-5.0 mm DV-6.8 mm). Contextual fear conditioning was measured 24 h after training, and tone fear conditioning 48 h after training. AP5 injections selectively impaired contextual fear conditioning only when injected pre-training. Post-training injections had no effect. These findings suggest that entorhinal cortex NMDA receptors are necessary for acquisition, but not for consolidation, of contextual fear conditioning. On the other hand, both acquisition and consolidation of tone fear conditioning seem to be independent of NMDA receptors in the entorhinal cortex.

  14. Optical coherence tomography visualizes neurons in human entorhinal cortex.

    PubMed

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

    2015-02-09

    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.

  15. Interneurons spark seizure-like activity in the entorhinal cortex.

    PubMed

    Lévesque, Maxime; Herrington, Rochelle; Hamidi, Shabnam; Avoli, Massimo

    2016-03-01

    Excessive neuronal synchronization is presumably involved in epileptiform synchronization. However, the respective roles played by interneurons (GABAergic) and principal (glutamatergic) cells during interictal and ictal discharges remain unclear. Here, we employed tetrode wire recordings to establish the involvement of these two cell types in 4-aminopyridine-induced interictal- and low-voltage fast (LVF) onset ictal-like discharges in the rat entorhinal cortex in an in vitro slice preparation. We recorded a total of 90 single units (69 putative interneurons, 17 putative principal and 4 unclassified cells) from 36 slices, and found that: (i) interneurons (66.7%) were more likely to fire during interictal discharges than principal cells (35.3%); (ii) interneuron activity increased shortly before LVF ictal onset, whereas principal cell activity did not change; (iii) interneurons and principal cells fired at high rates throughout the tonic phase of the ictal discharge; however, (iv) only interneurons showed phase-locked relationship with LVF activity at 5-15Hz during the tonic phase. Finally, the association of interneuron firing with interictal discharges was maintained during blockade of ionotropic glutamatergic transmission. Our findings demonstrate the prominent involvement of interneurons in interictal discharge generation and in the transition to LVF ictal activity in this in vitro model of epileptiform synchronization.

  16. A map of visual space in the primate entorhinal cortex.

    PubMed

    Killian, Nathaniel J; Jutras, Michael J; Buffalo, Elizabeth A

    2012-11-29

    Place-modulated activity among neurons in the hippocampal formation presents a means to organize contextual information in the service of memory formation and recall. One particular spatial representation, that of grid cells, has been observed in the entorhinal cortex (EC) of rats and bats, but has yet to be described in single units in primates. Here we examined spatial representations in the EC of head-fixed monkeys performing a free-viewing visual memory task. Individual neurons were identified in the primate EC that emitted action potentials when the monkey fixated multiple discrete locations in the visual field in each of many sequentially presented complex images. These firing fields possessed spatial periodicity similar to a triangular tiling with a corresponding well-defined hexagonal structure in the spatial autocorrelation. Further, these neurons showed theta-band oscillatory activity and changing spatial scale as a function of distance from the rhinal sulcus, which is consistent with previous findings in rodents. These spatial representations may provide a framework to anchor the encoding of stimulus content in a complex visual scene. Together, our results provide a direct demonstration of grid cells in the primate and suggest that EC neurons encode space during visual exploration, even without locomotion.

  17. GABAergic Somatostatin-immunoreactive Neurons in the Amygdala Project to the Entorhinal Cortex

    PubMed Central

    McDonald, Alexander J.; Zaric, Violeta

    2015-01-01

    The entorhinal cortex and other hippocampal and parahippocampal cortices are interconnected by a small number of GABAergic nonpyramidal neurons in addition to glutamatergic pyramidal cells. Since the cortical and basolateral amygdalar nuclei have cortex-like cell types and have robust projections to the entorhinal cortex, we hypothesized that a small number of amygdalar GABAergic nonpyramidal neurons might participate in amygdalo-entorhinal projections. To test this hypothesis we combined Fluorogold (FG) retrograde tract tracing with immunohistochemistry for the amygdalar nonpyramidal cell markers glutamic acid decarboxylase (GAD), parvalbumin (PV), somatostatin (SOM), neuropeptide Y (NPY), vasoactive intestinal peptide (VIP), and the m2 muscarinic cholinergic receptor (M2R). Injections of FG into the rat entorhinal cortex labeled numerous neurons that were mainly located in the cortical and basolateral nuclei of the amygdala. Although most of these amygdalar FG+ neurons labeled by entorhinal injections were large pyramidal cells, 1–5% were smaller long-range nonpyramidal neurons (LRNP neurons) that expressed SOM, or both SOM and NPY. No amygdalar FG+ neurons in these cases were PV+ or VIP+. Cell counts revealed that LRNP neurons labeled by injections into the entorhinal cortex constituted about 10–20% of the total SOM+ population, and 20–40% of the total NPY population in portions of the lateral amygdalar nucleus that exhibited a high density of FG+ neurons. Sixty-two percent of amygdalar FG+/SOM+ neurons were GAD+, and 51% were M2R+. Since GABAergic projection neurons typically have low perikaryal levels of GABAergic markers, it is actually possible that most or all of the amygdalar LRNP neurons are GABAergic. Like GABAergic LRNP neurons in hippocampal/parahippocampal regions, amygdalar LRNP neurons that project to the entorhinal cortex are most likely involved in synchronizing oscillatory activity between the two regions. These oscillations could entrain

  18. Autoradiographic study of the efferent connections of the entorhinal cortex in the rat

    SciTech Connect

    Wyss, J.M.

    1981-07-10

    The major findings can be summarized as follows. Whereas the projection of the lateral entorhinal area (LEA) to the dentate gyrus is broad in its longitudinal extent, the medial entorhinal area (MEA), and especially the ventral portion of this zone, projects in a more lamellar fashion. In the transverse plane the LEA preferentially projects to the inner (dorsal) blade of the dentate gyrus, while the MEA innervates both blades equally. Within the radial dimension, the entorhinal cortex projects to the dentate gyrus according to a medial to lateral gradient, with lateral portions of the LEA projecting along the pial surface and successively more medial portions of the entorhinal projecting closer to the granule cells. The commissural entorhinal to dentate projections are similar to the ipsilateral projections in location; however, they are considerably reduced in septotemporal extent and do not arise from cells in the ventral half of either LEA or the intermediate entorhinal area (IEA). The projection of the entorhinal cortex to Ammon's horn reflects the same longitudinal characteristics as the dentate projections. An alvear input which extends only to the pyramidal cells at the CA1-subicular junction was most noticeable at ventral hippocampal levels. The extrahippocampal projections arise predominantly from cells in the LEA and project forward along the angular bundle to the piriform and periamygdaloid cortices, as well as the endopiriform nucleus, the lateral, basolateral, and cortical amygdaloid nuclei, the nucleus of the lateral olfactory tract, the olfactory tubercle, the anterior olfactory nucleus, the taenia tecta, and the indusium griseum.

  19. Parvalbumin-immunoreactive neurons in the entorhinal cortex of the rat: localization, morphology, connectivity and ultrastructure.

    PubMed

    Wouterlood, F G; Härtig, W; Brückner, G; Witter, M P

    1995-02-01

    We studied the distribution, morphology, ultrastructure and connectivity of parvalbumin-immunoreactive neurons in the entorhinal cortex of the rat. Immunoreactive cell bodies were found in all layers of the entorhinal cortex except layer I. The highest numbers were observed in layers II and III of the dorsal division of the lateral entorhinal area whereas the lowest numbers occurred in the ventral division of the lateral entorhinal area. Most such neurons displayed multipolar configurations with smooth dendrites. We distinguished a type with long dendrites and a type with short dendrites. We also observed pyramidal immunoreactive neurons. A dense plexus of immunoreactive dendrites and axons was prominent in layers II and III of the dorsal division of the lateral entorhinal area and the medial entorhinal area. None of the parvalbumin-immunoreactive cells became retrogradely labelled after injection of horseradish peroxidase into the hippocampal formation. By electron microscopy, immunoreactivity was observed in cell bodies, dendrites, myelinated and unmyelinated axons and axon terminals. Immunoreactive dendrites and axons occurred in all cortical layers. We noted many myelinated immunoreactive axons. Immunoreactive axon terminals were medium sized, contained pleomorphic synaptic vesicles, and established symmetrical synapses. Both horseradish peroxidase labelled and unlabelled immunonegative cell bodies often received synapses from immunopositive axon terminals arranged in baskets. Synapses between immunoreactive axon terminals and unlabelled dendritic shafts and spines were abundant. Synapses with initial axon segments occurred less frequently. In addition, synaptic contacts were present between immunopositive axon terminals and cell bodies and dendrites. Thus, the several types of parvalbumin-containing neuron in the entorhinal cortex are interneurons, connected to one another and to immunonegative neurons through a network of synaptic contacts. Immunonegative

  20. Entorhinal cortex thickness predicts cognitive decline in Alzheimer's disease.

    PubMed

    Velayudhan, Latha; Proitsi, Petroula; Westman, Eric; Muehlboeck, J-Sebastian; Mecocci, Patrizia; Vellas, Bruno; Tsolaki, Magda; Kłoszewska, Iwona; Soininen, Hilkka; Spenger, Christian; Hodges, Angela; Powell, John; Lovestone, Simon; Simmons, Andrew

    2013-01-01

    Biomarkers for Alzheimer's disease (AD) based on non-invasive methods are highly desirable for diagnosis, disease progression, and monitoring therapeutics. We aimed to study the use of hippocampal volume, entorhinal cortex (ERC) thickness, and whole brain volume (WBV) as predictors of cognitive change in patients with AD. 120 AD subjects, 106 mild cognitive impairment (MCI), and 99 non demented controls (NDC) from the multi-center pan-European AddNeuroMed study underwent MRI scanning at baseline and clinical evaluations at quarterly follow-up up to 1 year. The rate of cognitive decline was estimated using cognitive outcomes, Mini-Mental State Examination (MMSE) and Alzheimer disease assessment scale-cognitive (ADAS-cog) by fitting a random intercept and slope model. AD subjects had smaller ERC thickness and hippocampal and WBV volumes compared to MCI and NDC subjects. Within the AD group, ERC > WBV was significantly associated with baseline cognition (MMSE, ADAS-cog) and disease severity (Clinical Dementia Rating). Baseline ERC thickness was associated with both longitudinal MMSE and ADAS-cog score changes and WBV with ADAS-cog decline. These data indicate that AD subjects with thinner ERC had lower baseline cognitive scores, higher disease severity, and predicted greater subsequent cognitive decline at one year follow up. ERC is a region known to be affected early in the disease. Therefore, the rate of atrophy in this structure is expected to be higher since neurodegeneration begins earlier. Focusing on structural analyses that predict decline can identify those individuals at greatest risk for future cognitive loss. This may have potential for increasing the efficacy of early intervention.

  1. Knife cuts of entorhinal cortex: effects on development of amygdaloid kindling and seizure-induced decrease of muscarinic cholinergic receptors

    SciTech Connect

    Savage, D.D.; Rigsbee, L.C.; McNamara, J.O.

    1985-02-01

    This report examines the effect of transection of the entorhinal hippocampal projection on amygdaloid kindling. We found that: bilateral knife cuts of entorhinal cortex but not of dorsal neocortex antagonize the development of amygdaloid kindling; and bilateral knife cuts of entorhinal cortex eliminate the seizure-induced decrease in number of muscarinic receptors of dentate granule cells. We suggest the following interpretations of these data: the hippocampal formation circuitry facilitates the development of amygdaloid kindling; and the decline of muscarinic receptors after kindled seizures is due to excessive activation of granule cells by axons from entorhinal cortex, a noncholinergic afferent.

  2. Cellular, columnar and modular organization of spatial representations in medial entorhinal cortex.

    PubMed

    Burgalossi, Andrea; Brecht, Michael

    2014-02-01

    Spatial discharge patterns in medial entorhinal cortex consist of grid, head direction, border and spatial-band cells. These firing patterns differ from the single-peaked fields of hippocampal place cells, in that they have well-defined geometries and extend throughout the available space. Such discharge properties could contribute to a metric representation of space. Both functional and anatomical evidence point to principal cell diversity, modularity and columnar organization, but linking entorhinal anatomy and physiology remains challenging. Layer 2 microcircuits consist of pyramidal neurons and a stellate cell network, which lacks recurrent excitation and is coupled by disynaptic inhibition. Intracellular recordings showed that periodic, grid-like firing emerges from depolarization ramps, whereas theta-oscillations determine spike timing. Interference with various inputs to entorhinal cortex abolishes grid activity, often without concomitant loss of hippocampal place activity.

  3. Conserved size and periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex.

    PubMed

    Naumann, Robert K; Ray, Saikat; Prokop, Stefan; Las, Liora; Heppner, Frank L; Brecht, Michael

    2016-03-01

    To understand the structural basis of grid cell activity, we compare medial entorhinal cortex architecture in layer 2 across five mammalian species (Etruscan shrews, mice, rats, Egyptian fruit bats, and humans), bridging ∼100 million years of evolutionary diversity. Principal neurons in layer 2 are divided into two distinct cell types, pyramidal and stellate, based on morphology, immunoreactivity, and functional properties. We confirm the existence of patches of calbindin-positive pyramidal cells across these species, arranged periodically according to analyses techniques like spatial autocorrelation, grid scores, and modifiable areal unit analysis. In rodents, which show sustained theta oscillations in entorhinal cortex, cholinergic innervation targeted calbindin patches. In bats and humans, which only show intermittent entorhinal theta activity, cholinergic innervation avoided calbindin patches. The organization of calbindin-negative and calbindin-positive cells showed marked differences in entorhinal subregions of the human brain. Layer 2 of the rodent medial and the human caudal entorhinal cortex were structurally similar in that in both species patches of calbindin-positive pyramidal cells were superimposed on scattered stellate cells. The number of calbindin-positive neurons in a patch increased from ∼80 in Etruscan shrews to ∼800 in humans, only an ∼10-fold over a 20,000-fold difference in brain size. The relatively constant size of calbindin patches differs from cortical modules such as barrels, which scale with brain size. Thus, selective pressure appears to conserve the distribution of stellate and pyramidal cells, periodic arrangement of calbindin patches, and relatively constant neuron number in calbindin patches in medial/caudal entorhinal cortex.

  4. Conserved size and periodicity of pyramidal patches in layer 2 of medial/caudal entorhinal cortex

    PubMed Central

    Naumann, Robert K.; Ray, Saikat; Prokop, Stefan; Las, Liora; Heppner, Frank L.

    2016-01-01

    ABSTRACT To understand the structural basis of grid cell activity, we compare medial entorhinal cortex architecture in layer 2 across five mammalian species (Etruscan shrews, mice, rats, Egyptian fruit bats, and humans), bridging ∼100 million years of evolutionary diversity. Principal neurons in layer 2 are divided into two distinct cell types, pyramidal and stellate, based on morphology, immunoreactivity, and functional properties. We confirm the existence of patches of calbindin‐positive pyramidal cells across these species, arranged periodically according to analyses techniques like spatial autocorrelation, grid scores, and modifiable areal unit analysis. In rodents, which show sustained theta oscillations in entorhinal cortex, cholinergic innervation targeted calbindin patches. In bats and humans, which only show intermittent entorhinal theta activity, cholinergic innervation avoided calbindin patches. The organization of calbindin‐negative and calbindin‐positive cells showed marked differences in entorhinal subregions of the human brain. Layer 2 of the rodent medial and the human caudal entorhinal cortex were structurally similar in that in both species patches of calbindin‐positive pyramidal cells were superimposed on scattered stellate cells. The number of calbindin‐positive neurons in a patch increased from ∼80 in Etruscan shrews to ∼800 in humans, only an ∼10‐fold over a 20,000‐fold difference in brain size. The relatively constant size of calbindin patches differs from cortical modules such as barrels, which scale with brain size. Thus, selective pressure appears to conserve the distribution of stellate and pyramidal cells, periodic arrangement of calbindin patches, and relatively constant neuron number in calbindin patches in medial/caudal entorhinal cortex. J. Comp. Neurol. 524:783–806, 2016. © 2015 The Authors. The Journal of Comparative Neurology Published by Wiley Periodicals, Inc. PMID:26223342

  5. Selective lesion to the entorhinal cortex leads to an impairment in familiarity but not recollection.

    PubMed

    Brandt, Karen R; Eysenck, Michael W; Nielsen, Maria Kragh; von Oertzen, Tim J

    2016-04-01

    The present research explored the effects of selective impairment to the entorhinal cortex on the processes of familiarity and recollection. To achieve this objective, the performance of patient MR, who has a selective impairment of the left entorhinal cortex, was compared to that of age and IQ-matched controls. Four experiments tested participants' recognition memory for familiar and unfamiliar faces and words. In all experiments, participants studied lists of items and then completed an old/new recognition test in which they also made remember/know/guess judgements. A fifth experiment tested participants' priming associated with the familiarity process. MR had intact performance in both face recognition experiments as well as having intact performance in pseudoword recognition. Crucially, however, in the familiar word experiment, whilst MR performed similarly to control participants in terms of recollection, she showed a marked impairment in familiarity. Furthermore, she also demonstrated a reversed conceptual priming effect. MR's impairment is both material-specific and selective for previously encountered but not new verbal items (pseudowords). These findings provide the first clear evidence that selective impairment of the entorhinal cortex impairs the familiarity process for familiar verbal material whilst leaving recollection intact. These results suggest the entorhinal cortex does not have attributes reflective of both recollection and familiarity as previously assumed, but rather supports context-free long-term familiarity-based recognition memory.

  6. Contributions of the hippocampus and entorhinal cortex to rapid visuomotor learning in rhesus monkeys.

    PubMed

    Yang, Tianming; Bavley, Rachel L; Fomalont, Kevin; Blomstrom, Kevin J; Mitz, Andrew R; Turchi, Janita; Rudebeck, Peter H; Murray, Elisabeth A

    2014-09-01

    The hippocampus and adjacent structures in the medial temporal lobe are essential for establishing new associative memories. Despite this knowledge, it is not known whether the hippocampus proper is essential for establishing such memories, nor is it known whether adjacent regions like the entorhinal cortex might contribute. To test the contributions of these regions to the formation of new associative memories, we trained rhesus monkeys to rapidly acquire arbitrary visuomotor associations, i.e., associations between visual stimuli and spatially directed actions. We then assessed the effects of reversible inactivations of either the hippocampus (Experiment 1) or entorhinal cortex (Experiment 2) on the within-session rate of learning. For comparison, we also evaluated the effects of the inactivations on performance of problems of the same type that had been well learned prior to any inactivations. We found that inactivation of the entorhinal cortex but not hippocampus produced impairments in acquiring novel arbitrary associations. The impairment did not extend to the familiar, previously established associations. These data indicate that the entorhinal cortex is causally involved in establishing new associations, as opposed to retrieving previously learned associations. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  7. 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…

  8. Effect of early isolation on signal transfer in the entorhinal cortex-dentate-hippocampal system.

    PubMed

    Bartesaghi, R; Raffi, M; Ciani, E

    2006-02-01

    Deprivation of socio-sensory interactions during early life impairs brain function in adulthood. In previous investigations we showed that early isolation severely affects neuron development in several structures of the hippocampal region, including the entorhinal cortex. In the present study we investigated the effects of early isolation on signal processing along the entorhinal cortex-dentate-CA3-CA1 system, a major memory circuit of the hippocampal region. Male and female guinea-pigs were assigned at 6-7 days of age to either a social or an isolated environment. At 90-100 days of age the animals were anesthetized and field potentials were recorded from the entorhinal cortex-dentate-CA3-CA1 circuit, driven by dorsal psalterium commissural volleys. Analysis of the input-output function in the different structures showed that in isolated males there was a small reduction in the input-output function of the population excitatory postsynaptic potential and population spike evoked in layer II of the entorhinal cortex. No changes occurred in isolated females. In isolated males and females there was a reduction in the input-output function of the population excitatory postsynaptic potential and population spike evoked in the dentate gyrus, CA3 and CA1, but this effect was larger in males. In isolated males, but not in females, the population spike/population excitatory postsynaptic potential ratio was reduced in all investigated structures, indicating that in males the size of the discharged neuron population was reduced more than due to the decreased input. Results show that isolation reduces the synaptic function in the whole entorhinal cortex-dentate gyrus-CA3-CA1 system. While the entorhinal cortex was moderately impaired, the dentate-hippocampal system was more severely affected. The impairment in the signal transfer along the entorhinal cortex-dentate gyrus-CA3-CA1 system was heavier in males, confirming the larger susceptibility of this sex to early experience

  9. 6-Hydroxydopamine and radiofrequency lesions of the lateral entorhinal cortex facilitate an operant appetitive conditioning task in mice.

    PubMed

    Gauthier, M; Soumireu-Mourat, B

    1981-07-02

    The entorhinal cortex seems heterogeneous as dopaminergic terminals are present only in the anterior part of the lateral entorhinal cortex. In order to clarify the interaction of this cortex with the hippocampus in memory processes, the effects of either 6-hydroxydopamine or radiofrequency bilateral lesions were compared. Both lesions enhance the retention of a Skinner task with continuous reinforcement schedule. Involvement of dopamine in memory processes is discussed.

  10. Neuronal rebound spiking, resonance frequency and theta cycle skipping may contribute to grid cell firing in medial entorhinal cortex.

    PubMed

    Hasselmo, Michael E

    2014-02-05

    Data show a relationship of cellular resonance and network oscillations in the entorhinal cortex to the spatial periodicity of grid cells. This paper presents a model that simulates the resonance and rebound spiking properties of entorhinal neurons to generate spatial periodicity dependent upon phasic input from medial septum. The model shows that a difference in spatial periodicity can result from a difference in neuronal resonance frequency that replicates data from several experiments. The model also demonstrates a functional role for the phenomenon of theta cycle skipping in the medial entorhinal cortex.

  11. Medial entorhinal cortex lesions only partially disrupt hippocampal place cells and hippocampus-dependent place memory

    PubMed Central

    Hales, Jena B; Schlesiger, Magdalene I; Leutgeb, Jill K; Squire, Larry R; Leutgeb, Stefan; Clark, Robert E

    2014-01-01

    SUMMARY Entorhinal cortex provides the primary cortical projections to the hippocampus, a brain structure critical for memory. However, it remains unclear how the precise firing patterns of medial entorhinal cortex (MEC) cells influence hippocampal physiology and hippocampus-dependent behavior. We found that complete bilateral lesions of MEC resulted in a lower proportion of active hippocampal cells. The remaining active cells had place fields, but with decreased spatial precision and decreased long-term spatial stability. In addition, MEC rats were as impaired at acquiring the watermaze as hippocampus rats, while rats with combined MEC and hippocampal lesions had an even greater deficit. However, MEC rats were not impaired on other hippocampus-dependent tasks, including those in which an object location or context was remembered. Thus, MEC is not necessary for all types of spatial coding, nor for all types of hippocampus-dependent memory, but is necessary for the normal acquisition of place memory. PMID:25437546

  12. Running Induces Widespread Structural Alterations in the Hippocampus and Entorhinal Cortex

    PubMed Central

    Stranahan, Alexis M.; Khalil, David; Gould, Elizabeth

    2010-01-01

    Physical activity enhances hippocampal function but its effects on neuronal structure remain relatively unexplored outside of the dentate gyrus. Using Golgi impregnation and the lipophilic tracer DiI, we show that long-term voluntary running increases the density of dendritic spines in the entorhinal cortex and hippocampus of adult rats. Exercise was associated with increased dendritic spine density not only in granule neurons of the dentate gyrus, but also in CA1 pyramidal neurons, and in layer III pyramidal neurons of the entorhinal cortex. In the CA1 region, changes in dendritic spine density are accompanied by changes in dendritic arborization and alterations in the morphology of individual spines. These findings suggest that physical activity exerts pervasive effects on neuronal morphology in the hippocampus and one of its afferent populations. These structural changes may contribute to running-induced changes in cognitive function. PMID:17636549

  13. 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.

  14. Voltage dependence of subthreshold resonance frequency in layer II of medial entorhinal cortex.

    PubMed

    Shay, Christopher F; Boardman, Ian S; James, Nicholas M; Hasselmo, Michael E

    2012-08-01

    The resonance properties of individual neurons in entorhinal cortex (EC) may contribute to their functional properties in awake, behaving rats. Models propose that entorhinal grid cells could arise from shifts in the intrinsic frequency of neurons caused by changes in membrane potential owing to depolarizing input from neurons coding velocity. To test for potential changes in intrinsic frequency, we measured the resonance properties of neurons at different membrane potentials in neurons in medial and lateral EC. In medial entorhinal neurons, the resonant frequency of individual neurons decreased in a linear manner as the membrane potential was depolarized between -70 and -55 mV. At more hyperpolarized membrane potentials, cells asymptotically approached a maximum resonance frequency. Consistent with the previous studies, near resting potential, the cells of the medial EC possessed a decreasing gradient of resonance frequency along the dorsal to ventral axis, and cells of the lateral EC lacked resonant properties, regardless of membrane potential or position along the medial to lateral axis within lateral EC. Application of 10 μM ZD7288, the H-channel blocker, abolished all resonant properties in MEC cells, and resulted in physiological properties very similar to lateral EC cells. These results on resonant properties show a clear change in frequency response with depolarization that could contribute to the generation of grid cell firing properties in the medial EC.

  15. Context-dependent spatially periodic activity in the human entorhinal cortex.

    PubMed

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

    2017-04-10

    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.

  16. Deep layer neurons in the rat medial entorhinal cortex fire sparsely irrespective of spatial novelty.

    PubMed

    Burgalossi, Andrea; von Heimendahl, Moritz; Brecht, Michael

    2014-01-01

    Extracellular recordings in medial entorhinal cortex have revealed the existence of spatially-modulated firing patterns, which are thought to contribute to a cognitive map of external space. Previous work indicated that during exploration of novel environments, spiking activity in deep entorhinal layers is much sparser than in superficial layers. In the present report, we ask whether this laminar activity profile is a consequence of environmental novelty. We report on a large dataset of juxtacellularly-recorded neurons (n = 70) whose spiking activity was monitored while rats explored either a novel or a familiar environment, or both within the same session. Irrespective of previous knowledge of the environment, deep layer activity was very low during exploration (median firing rate 0.4 Hz for non-silent cells), with a large fraction of silent cells (n = 19 of a total 37), while superficial layer activity was several times higher (median firing rate 2.4 Hz; n = 33). The persistence of laminar differences in firing activity both under environmental novelty and familiarity, and even in head-restrained stationary animals, suggests that sparse coding might be a constitutive feature of deep entorhinal layers.

  17. Signal transduction mechanisms within the entorhinal cortex that support latent inhibition of cued fear conditioning.

    PubMed

    Lewis, Michael C; Gould, Thomas J

    2007-10-01

    Latent inhibition is a phenomenon by which pre-exposure to a conditioned-stimulus (CS), prior to subsequent pairings of that same CS with an unconditioned-stimulus (US), results in decreased conditioned responding to the CS. Previous work in our laboratory has suggested that the entorhinal cortex is critically involved in the establishment of latent inhibition of cued fear conditioning. Furthermore, utilizing systemic pharmacology, we have demonstrated a role for of NMDA receptors, protein kinase A (PKA), and mitogen activated protein kinase (MAPK, also known as ERK) in latent inhibition of cued fear conditioning, but until now, where these cell signaling cascades are critically activated during latent inhibition of cued fear was unknown. Here, we use direct drug infusion to demonstrate that cell signaling via NMDA receptors, the cAMP/PKA pathway, and the MAPK pathway within the entorhinal cortex are critically involved in latent inhibition of cued fear conditioning. In the present study, CS pre-exposed mice received 20 CS pre-exposures 24h prior to two pairings of the same CS with a 0.53 mA foot shock US, while control animals receive no pre-exposure to the CS. The NMDA antagonist APV (0.25 or 2.5 microg/side), the cAMP inhibitor Rp-cAMP (1.8 or 18.0 microg/side), or the MAPK inhibitor U0126 (0.1 or 1.0 microg/side) were directly infused into the entorhinal cortex prior to pre-exposure. All three drugs produced dose-dependent disruptions in latent inhibition of cued fear conditioning. Importantly, none of the drugs had any effect on cued fear conditioning when administered on training day, suggesting that the effects of each of the drugs were specific to CS pre-exposure. These results are discussed in relation to the potential mechanisms of plasticity that support latent inhibition of cued fear conditioning.

  18. Inhibition of TRPV1 channels enables long-term potentiation in the entorhinal cortex.

    PubMed

    Banke, Tue G

    2016-04-01

    The transient receptor potential vanilloid 1 (TRPV1) channel is a non-selective cation channel that is mainly found in nociceptive neurons of the peripheral nervous system; however, these channels have also been located within the CNS, including the entorhinal cortex. Whole-cell patch-clamp recordings of principal entorhinal cortex (EC) layers II/III neurons revealed that evoked inhibitory postsynaptic currents were depressed by application of the TRPV1 agonist capsaicin (CAP), accompanied by a change in the pair-pulse ratio (PPR). In addition, recordings of miniature inhibitory postsynaptic currents (mIPSCs) revealed that inter-event intervals but not amplitude were decreased in wild-type (WT) after application of CAP. This suggests that TRPV1 channels are functional in the entorhinal cortex and are located on inhibitory neurons with their axonal arborization within layers II/III. In order to study TRPV1 channels and their involvement in long-term potentiation (LTP) induction in a more intact circuit, extracellular field potential recordings were performed in EC layers II/III. It was found that activated TRPV1 channels preclude induction of long-term potentiation. In sharp contrast, clear LTP was observed when antagonizing TRPV1 channels or recording from TRPV1 knock-out mice. Thus, these results suggests that signaling through activating inhibitory presynaptic TRPV1 channels represents a novel mechanism by which a shift in feed-forward inhibition of layers II/III cortical principal neurons prompt changes in synaptic strength and thereby contribute to a change of information storage within the brain.

  19. Infusion of protein synthesis inhibitors in the entorhinal cortex blocks consolidation but not reconsolidation of object recognition memory.

    PubMed

    Lima, Ramón H; Rossato, Janine I; Furini, Cristiane R; Bevilaqua, Lia R; Izquierdo, Iván; Cammarota, Martín

    2009-05-01

    Memory consolidation and reconsolidation require the induction of protein synthesis in some areas of the brain. Here, we show that infusion of the protein synthesis inhibitors anisomycin, emetine and cycloheximide in the entorhinal cortex immediately but not 180 min or 360 min after training in an object recognition learning task hinders long-term memory retention without affecting short-term memory or behavioral performance. Inhibition of protein synthesis in the entorhinal cortex after memory reactivation involving either a combination of familiar and novel objects or two familiar objects does not affect retention. Our data suggest that protein synthesis in the entorhinal cortex is necessary early after training for consolidation of object recognition memory. However, inhibition of protein synthesis in this cortical region after memory retrieval does not seem to affect the stability of the recognition trace.

  20. Optogenetic dissection of ictal propagation in the hippocampal–entorhinal cortex structures

    PubMed Central

    Lu, Yi; Zhong, Cheng; Wang, Lulu; Wei, Pengfei; He, Wei; Huang, Kang; Zhang, Yi; Zhan, Yang; Feng, Guoping; Wang, Liping

    2016-01-01

    Temporal lobe epilepsy (TLE) is one of the most common drug-resistant forms of epilepsy in adults and usually originates in the hippocampal formations. However, both the network mechanisms that support the seizure spread and the exact directions of ictal propagation remain largely unknown. Here we report the dissection of ictal propagation in the hippocampal–entorhinal cortex (HP–EC) structures using optogenetic methods in multiple brain regions of a kainic acid-induced model of TLE in VGAT-ChR2 transgenic mice. We perform highly temporally precise cross-area analyses of epileptic neuronal networks and find a feed-forward propagation pathway of ictal discharges from the dentate gyrus/hilus (DGH) to the medial entorhinal cortex, instead of a re-entrant loop. We also demonstrate that activating DGH GABAergic interneurons can significantly inhibit the spread of ictal seizures and largely rescue behavioural deficits in kainate-exposed animals. These findings may shed light on future therapeutic treatments of TLE. PMID:26997093

  1. 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

  2. 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

  3. Spontaneous persistent activity in entorhinal cortex modulates cortico-hippocampal interaction in vivo

    PubMed Central

    Hahn, Thomas T. G.; McFarland, James M.; Berberich, Sven; Sakmann, Bert; Mehta, Mayank R.

    2013-01-01

    Persistent activity is thought to mediate working memory during behavior. Can it also occur during sleep? We show that the membrane potential of medial entorhinal cortex layer III (MECIII) neurons, a gateway between neocortex and hippocampus, showed spontaneous, stochastic persistent activity in vivo in mice during Up-Down state oscillations (UDS). This persistent activity was locked to the neocortical Up states with a short delay, but persisted over several cortical UDS cycles. Lateral entorhinal (LECIII) neurons did not show significant persistence, and current injections similar to those used in vitro failed to elicit persistence in vivo, thus implicating network mechanisms. Hippocampal CA1 neurons’ activity was reduced during neocortical Up states, but was increased during MECIII persistent states. These results provide the first direct evidence for persistent activity in MECIII neurons in vivo, and reveal its contribution to cortico-hippocampal interaction, which could be involved in working memory and learning of long behavioral sequences during behavior, and memory consolidation during sleep. PMID:23042081

  4. Medial entorhinal cortex and medial septum contribute to self-motion-based linear distance estimation.

    PubMed

    Jacob, Pierre-Yves; Gordillo-Salas, Marta; Facchini, Justine; Poucet, Bruno; Save, Etienne; Sargolini, Francesca

    2017-02-04

    Path integration is a navigation strategy that requires animals to integrate self-movements during exploration to determine their position in space. The medial entorhinal cortex (MEC) has been suggested to play a pivotal role in this process. Grid cells, head-direction cells, border cells as well as speed cells within the MEC collectively provide a dynamic representation of the animal position in space based on the integration of self-movements. All these cells are strongly modulated by theta oscillations, thus suggesting that theta rhythmicity in the MEC may be essential for integrating and coordinating self-movement information during navigation. In this study, we first show that excitotoxic MEC lesions, but not dorsal hippocampal lesions, impair the ability of rats to estimate linear distances based on self-movement information. Next, we report similar deficits following medial septum inactivation, which strongly impairs theta oscillations in the entorhinal-hippocampal circuits. Taken together, these findings demonstrate a major role of the MEC and MS in estimating distances to be traveled, and point to theta oscillations within the MEC as a neural mechanism responsible for the integration of information generated by linear self-displacements.

  5. Saccade direction encoding in the primate entorhinal cortex during visual exploration.

    PubMed

    Killian, Nathaniel J; Potter, Steve M; Buffalo, Elizabeth A

    2015-12-22

    We recently demonstrated that position in visual space is represented by grid cells in the primate entorhinal cortex (EC), suggesting that visual exploration of complex scenes in primates may employ signaling mechanisms similar to those used during exploration of physical space via movement in rodents. Here, we describe a group of saccade direction (SD) cells that encode eye movement information in the monkey EC during free-viewing of complex images. Significant saccade direction encoding was found in 20% of the cells recorded in the posterior EC. SD cells were generally broadly tuned and two largely separate populations of SD cells encoded future and previous saccade direction. Some properties of these cells resemble those of head-direction cells in rodent EC, suggesting that the same neural circuitry may be capable of performing homologous spatial computations under different exploratory contexts.

  6. Molecularly Defined Circuitry Reveals Input-Output Segregation in Deep Layers of the Medial Entorhinal Cortex.

    PubMed

    Sürmeli, Gülşen; Marcu, Daniel Cosmin; McClure, Christina; Garden, Derek L F; Pastoll, Hugh; Nolan, Matthew F

    2015-12-02

    Deep layers of the medial entorhinal cortex are considered to relay signals from the hippocampus to other brain structures, but pathways for routing of signals to and from the deep layers are not well established. Delineating these pathways is important for a circuit level understanding of spatial cognition and memory. We find that neurons in layers 5a and 5b have distinct molecular identities, defined by the transcription factors Etv1 and Ctip2, and divergent targets, with extensive intratelencephalic projections originating in layer 5a, but not 5b. This segregation of outputs is mirrored by the organization of glutamatergic input from stellate cells in layer 2 and from the hippocampus, with both preferentially targeting layer 5b over 5a. Our results suggest a molecular and anatomical organization of input-output computations in deep layers of the MEC, reveal precise translaminar microcircuitry, and identify molecularly defined pathways for spatial signals to influence computation in deep layers.

  7. Grid-layout and theta-modulation of layer 2 pyramidal neurons in medial entorhinal cortex.

    PubMed

    Ray, Saikat; Naumann, Robert; Burgalossi, Andrea; Tang, Qiusong; Schmidt, Helene; Brecht, Michael

    2014-02-21

    Little is known about how microcircuits are organized in layer 2 of the medial entorhinal cortex. We visualized principal cell microcircuits and determined cellular theta-rhythmicity in freely moving rats. Non-dentate-projecting, calbindin-positive pyramidal cells bundled dendrites together and formed patches arranged in a hexagonal grid aligned to layer 1 axons, parasubiculum, and cholinergic inputs. Calbindin-negative, dentate-gyrus-projecting stellate cells were distributed across layer 2 but avoided centers of calbindin-positive patches. Cholinergic drive sustained theta-rhythmicity, which was twofold stronger in pyramidal than in stellate neurons. Theta-rhythmicity was cell-type-specific but not distributed as expected from cell-intrinsic properties. Layer 2 divides into a weakly theta-locked stellate cell lattice and spatiotemporally highly organized pyramidal grid. It needs to be assessed how these two distinct principal cell networks contribute to grid cell activity.

  8. Subthreshold Membrane-Potential Resonances Shape Spike-Train Patterns in the Entorhinal Cortex

    PubMed Central

    Engel, T. A.; Schimansky-Geier, L.; Herz, A.V.M.; Schreiber, S.; Erchova, I.

    2008-01-01

    Many neurons exhibit subthreshold membrane-potential resonances, such that the largest voltage responses occur at preferred stimulation frequencies. Because subthreshold resonances are known to influence the rhythmic activity at the network level, it is vital to understand how they affect spike generation on the single-cell level. We therefore investigated both resonant and nonresonant neurons of rat entorhinal cortex. A minimal resonate-and-fire type model based on measured physiological parameters captures fundamental properties of neuronal firing statistics surprisingly well and helps to shed light on the mechanisms that shape spike patterns: 1) subthreshold resonance together with a spike-induced reset of subthreshold oscillations leads to spike clustering and 2) spike-induced dynamics influence the fine structure of interspike interval (ISI) distributions and are responsible for ISI correlations appearing at higher firing rates (≥3 Hz). Both mechanisms are likely to account for the specific discharge characteristics of various cell types. PMID:18450582

  9. Grid cells without theta oscillations in the entorhinal cortex of bats.

    PubMed

    Yartsev, Michael M; Witter, Menno P; Ulanovsky, Nachum

    2011-11-02

    Grid cells provide a neural representation of space, by discharging when an animal traverses through the vertices of a periodic hexagonal grid spanning the environment. Although grid cells have been characterized in detail in rats, the fundamental question of what neural dynamics give rise to the grid structure remains unresolved. Two competing classes of models were proposed: network models, based on attractor dynamics, and oscillatory interference models, which propose that interference between somatic and dendritic theta-band oscillations (4-10 Hz) in single neurons transforms a temporal oscillation into a spatially periodic grid. So far, these models could not be dissociated experimentally, because rodent grid cells always co-exist with continuous theta oscillations. Here we used a novel animal model, the Egyptian fruit bat, to refute the proposed causal link between grids and theta oscillations. On the basis of our previous finding from bat hippocampus, of spatially tuned place cells in the absence of continuous theta oscillations, we hypothesized that grid cells in bat medial entorhinal cortex might also exist without theta oscillations. Indeed, we found grid cells in bat medial entorhinal cortex that shared remarkable similarities to rodent grid cells. Notably, the grids existed in the absence of continuous theta-band oscillations, and with almost no theta modulation of grid-cell spiking--both of which are essential prerequisites of the oscillatory interference models. Our results provide a direct demonstration of grid cells in a non-rodent species. Furthermore, they strongly argue against a major class of computational models of grid cells.

  10. Entorhinal cortex structure and functional MRI response during an associative verbal memory task.

    PubMed

    Braskie, Meredith N; Small, Gary W; Bookheimer, Susan Y

    2009-12-01

    Entorhinal cortex (ERC) volume in adults with mild cognitive impairment has been shown to predict prodromal Alzheimer's disease (AD). Likewise, neuronal loss in ERC has been associated with AD, but not with normal aging. Because ERC is part of a major pathway modulating input to the hippocampus, structural changes there may result in changes to cognitive performance and functional brain activity during memory tasks. In 32 cognitively intact older adults, we examined the relationship between left ERC thickness and functional magnetic resonance imaging (fMRI) activity during an associative verbal memory task. This task has been shown previously to activate regions that are sensitive to aging and AD risk. ERC was manually defined on native space, high resolution, oblique coronal MRI scans. Subjects having thicker left ERC showed greater activation in anterior cingulate and medial frontal regions during memory retrieval, but not encoding. This result was independent of hippocampal volume. Anterior cingulate cortex is directly connected to ERC, and is, along with medial frontal cortex, implicated in error detection, which is impaired in AD. Our results suggest that in healthy older adults, processes that engage frontal regions during memory retrieval are related to ERC structure.

  11. Entorhinal cortex volume in older adults: reliability and validity considerations for three published measurement protocols.

    PubMed

    Price, C C; Wood, M F; Leonard, C M; Towler, S; Ward, J; Montijo, H; Kellison, I; Bowers, D; Monk, T; Newcomer, J C; Schmalfuss, I

    2010-09-01

    Measuring the entorhinal cortex (ERC) is challenging due to lateral border discrimination from the perirhinal cortex. From a sample of 39 nondemented older adults who completed volumetric image scans and verbal memory indices, we examined reliability and validity concerns for three ERC protocols with different lateral boundary guidelines (i.e., Goncharova, Dickerson, Stoub, & deToledo-Morrell, 2001; Honeycutt et al., 1998; Insausti et al., 1998). We used three novice raters to assess inter-rater reliability on a subset of scans (216 total ERCs), with the entire dataset measured by one rater with strong intra-rater reliability on each technique (234 total ERCs). We found moderate to strong inter-rater reliability for two techniques with consistent ERC lateral boundary endpoints (Goncharova, Honeycutt), with negligible to moderate reliability for the technique requiring consideration of collateral sulcal depth (Insausti). Left ERC and story memory associations were moderate and positive for two techniques designed to exclude the perirhinal cortex (Insausti, Goncharova), with the Insausti technique continuing to explain 10% of memory score variance after additionally controlling for depression symptom severity. Right ERC-story memory associations were nonexistent after excluding an outlier. Researchers are encouraged to consider challenges of rater training for ERC techniques and how lateral boundary endpoints may impact structure-function associations.

  12. 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

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

    PubMed

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

    2016-03-01

    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.

  14. 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 GABAA 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.

  15. 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.

  16. Parallel processing of information about location in the amygdala, entorhinal cortex and hippocampus.

    PubMed

    Gaskin, Stephane; White, Norman M

    2013-11-01

    The conditioned cue preference paradigm was used to study how rats use extra-maze cues to discriminate between 2 adjacent arms on an 8-arm radial maze, a situation in which most of the same cues can be seen from both arms but only one arm contains food. Since the food-restricted rats eat while passively confined on the food-paired arm no responses are reinforced, so the discrimination is due to Pavlovian stimulus-reward (or outcome) learning. Consistent with other evidence that rats must move around in an environment to acquire a spatial map, we found that learning the adjacent arms CCP (ACCP) required a minimum amount of active exploration of the maze with no reinforcers present prior to passive pairing of the extra-maze cues with the food reinforcer, an instance of latent learning. Temporary inactivation of the hippocampus during the pre-exposure sessions had no effect on ACCP learning, confirming other evidence that the hippocampus is not involved in latent learning. A series of experiments indentified a circuit involving fimbria-fornix and dorsal entorhinal cortex as the neural basis of latent learning in this situation. In contrast, temporary inactivation of the entorhinal cortex or hippocampus during passive training or during testing blocked ACCP learning and expression, respectively, suggesting that these two structures co-operate in using spatial information to learn the location of food on the maze during passive pairing and to express this combined information during testing. In parallel with these processes we found that the amygdala processes information leading to an equal tendency to enter both adjacent arms (even though only one was paired with food) suggesting that the stimulus information available to this structure is not sufficiently precise to discriminate between the ambiguous cues visible from the adjacent arms. Expression of the ACCP in normal rats depends on hippocampus-based learning to avoid the unpaired arm which competes with the

  17. Parvalbumin interneurons provide grid cell-driven recurrent inhibition in the medial entorhinal cortex.

    PubMed

    Buetfering, Christina; Allen, Kevin; Monyer, Hannah

    2014-05-01

    Grid cells in the medial entorhinal cortex (MEC) generate metric spatial representations. Recent attractor-network models suggest an essential role for GABAergic interneurons in the emergence of the grid-cell firing pattern through recurrent inhibition dependent on grid-cell phase. To test this hypothesis, we studied identified parvalbumin-expressing (PV(+)) interneurons that are the most likely candidate for providing this recurrent inhibition onto grid cells. Using optogenetics and tetrode recordings in mice, we found that PV(+) interneurons exhibited high firing rates, low spatial sparsity and no spatial periodicity. PV(+) interneurons inhibited all functionally defined cell types in the MEC and were in turn recruited preferentially by grid cells. To our surprise, we found that individual PV(+) interneurons received input from grid cells with various phases, which most likely accounts for the broadly tuned spatial firing activity of PV(+) interneurons. Our data argue against the notion that PV(+) interneurons provide phase-dependent recurrent inhibition and challenge recent attractor-network models of grid cells.

  18. The entorhinal cortex is involved in conditioned odor and context aversions

    PubMed Central

    Ferry, Barbara; Herbeaux, Karine; Javelot, Hervé; Majchrzak, Monique

    2015-01-01

    In a natural environment, avoidance of a particular food source is mostly determined by a previous intake experience during which sensory stimuli such as food odor, become aversive through a simple associative conditioned learning. Conditioned odor aversion learning (COA) is a food conditioning paradigm that results from the association between a tasteless scented solution (conditioned stimulus, CS) and a gastric malaise (unconditioned stimulus, US) that followed its ingestion. In the present experimental conditions, acquisition of COA also led to acquisition of aversion toward the context in which the CS was presented (conditioned context aversion, CCA). Previous data have shown that the entorhinal cortex (EC) is involved in the memory processes underlying COA acquisition and context fear conditioning, but whether EC lesion modulates CCA acquisition has never be investigated. To this aim, male Long-Evans rats with bilateral EC lesion received CS-US pairings in a particular context with different interstimulus intervals (ISI). The results showed that the establishment of COA with long ISI obtained in EC-lesioned rats is associated with altered CCA learning. Since ISI has been suggested to be the determining factor in the odor- and context-US association, our results show that the EC is involved in the processes that control both associations relative to ISI duration. PMID:26483624

  19. Dopaminergic regulation of neuronal excitability through modulation of Ih in layer V entorhinal cortex.

    PubMed

    Rosenkranz, J Amiel; Johnston, Daniel

    2006-03-22

    The entorhinal cortex (EC) is a significant component of the systems that underlie certain forms of memory formation and recall. Evidence has been emerging that the dopaminergic system in the EC facilitates these and other functions of the EC. The effects of dopamine (DA) on membrane properties and excitability of EC neurons, however, are not known. We used in vitro whole-cell patch-clamp recordings from layer V pyramidal neuronal somata and dendrites of the adult rat lateral EC to investigate the effects of DA on the excitability of these neurons. We found that brief application of DA caused a reduction in the excitability of layer V EC pyramidal neurons. This effect was attributable to voltage-dependent modification of membrane properties that can best be explained by an increase in a hyperpolarization-activated conductance. Furthermore, the effects of DA were blocked by pharmacological blockade of h-channels, but not by any of a number of other ion channels. These actions were produced by a D1 receptor-mediated increase of cAMP but were independent of protein kinase A. A portion of the actions of DA can be attributed to effects in the apical dendrites. The data suggest that DA can directly influence the membrane properties of layer V EC pyramidal neurons by modulation of h-channels. These actions may underlie some of the effects of DA on memory formation.

  20. Alteration of transcriptional networks in the entorhinal cortex after maternal immune activation and adolescent cannabinoid exposure.

    PubMed

    Hollins, Sharon L; Zavitsanou, Katerina; Walker, Frederick Rohan; Cairns, Murray J

    2016-08-01

    Maternal immune activation (MIA) and adolescent cannabinoid exposure (ACE) have both been identified as major environmental risk factors for schizophrenia. We examined the effects of these two risk factors alone, and in combination, on gene expression during late adolescence. Pregnant rats were exposed to the viral infection mimic polyriboinosinic-polyribocytidylic acid (poly I:C) on gestational day (GD) 15. Adolescent offspring received daily injections of the cannabinoid HU210 for 14days starting on postnatal day (PND) 35. Gene expression was examined in the left entorhinal cortex (EC) using mRNA microarrays. We found prenatal treatment with poly I:C alone, or HU210 alone, produced relatively minor changes in gene expression. However, following combined treatments, offspring displayed significant changes in transcription. This dramatic and persistent alteration of transcriptional networks enriched with genes involved in neurotransmission, cellular signalling and schizophrenia, was associated with a corresponding perturbation in the expression of small non-coding microRNA (miRNA). These results suggest that a combination of environmental exposures during development leads to significant genomic remodeling that disrupts maturation of the EC and its associated circuitry with important implications as the potential antecedents of memory and learning deficits in schizophrenia and other neuropsychiatric disorders.

  1. Exposure to extremely low frequency electromagnetic fields alters the calcium dynamics of cultured entorhinal cortex neurons.

    PubMed

    Luo, Fen-Lan; Yang, Nian; He, Chao; Li, Hong-Li; Li, Chao; Chen, Fang; Xiong, Jia-Xiang; Hu, Zhi-An; Zhang, Jun

    2014-11-01

    Previous studies have revealed that extremely low frequency electromagnetic field (ELF-EMF) exposure affects neuronal dendritic spine density and NMDAR and AMPAR subunit expressions in the entorhinal cortex (EC). Although calcium signaling has a critical role in control of EC neuronal functions, however, it is still unclear whether the ELF-EMF exposure affects the EC neuronal calcium homeostasis. In the present study, using whole-cell recording and calcium imaging, we record the whole-cell inward currents that contain the voltage-gated calcium currents and show that ELF-EMF (50Hz, 1mT or 3mT, lasting 24h) exposure does not influence these currents. Next, we specifically isolate the high-voltage activated (HVA) and low-voltage activated (LVA) calcium channels-induced currents. Similarly, the activation and inactivation characteristics of these membrane calcium channels are also not influenced by ELF-EMF. Importantly, ELF-EMF exposure reduces the maximum amplitude of the high-K(+)-evoked calcium elevation in EC neurons, which is abolished by thapsigargin, a Ca(2+) ATPase inhibitor, to empty the intracellular calcium stores of EC neurons. Together, these findings indicate that ELF-EMF exposure specifically influences the intracellular calcium dynamics of cultural EC neurons via a calcium channel-independent mechanism.

  2. Synaptic Conductances during Interictal Discharges in Pyramidal Neurons of Rat Entorhinal Cortex

    PubMed Central

    Amakhin, Dmitry V.; Ergina, Julia L.; Chizhov, Anton V.; Zaitsev, Aleksey V.

    2016-01-01

    In epilepsy, the balance of excitation and inhibition underlying the basis of neural network activity shifts, resulting in neuronal network hyperexcitability and recurrent seizure-associated discharges. Mechanisms involved in ictal and interictal events are not fully understood, in particular, because of controversial data regarding the dynamics of excitatory and inhibitory synaptic conductances. In the present study, we estimated AMPAR-, NMDAR-, and GABAA R-mediated conductances during two distinct types of interictal discharge (IID) in pyramidal neurons of rat entorhinal cortex in cortico-hippocampal slices. Repetitively emerging seizure-like events and IIDs were recorded in high extracellular potassium, 4-aminopyridine, and reduced magnesium-containing solution. An original procedure for estimating synaptic conductance during IIDs was based on the differences among the current-voltage characteristics of the synaptic components. The synaptic conductance dynamics obtained revealed that the first type of IID is determined by activity of GABAA R channels with depolarized reversal potential. The second type of IID is determined by the interplay between excitation and inhibition, with early AMPAR and prolonged depolarized GABAA R and NMDAR-mediated components. The study then validated the contribution of these components to IIDs by intracellular pharmacological isolation. These data provide new insights into the mechanisms of seizures generation, development, and cessation. PMID:27790093

  3. 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

  4. Innervation from the entorhinal cortex to the dentate gyrus and the vulnerability to Zn(2).

    PubMed

    Takeda, Atsushi; Tamano, Hanuna

    2016-12-01

    Hippocampal Zn(2+) homeostasis is critical for cognitive activity and hippocampus-dependent memory. Extracellular Zn(2+) signaling is linked to extracellular glutamate signaling and leads to intracellular Zn(2+) signaling, which is involved in cognitive activity. On the other hand, excess intracellular Zn(2+) signaling that is induced by excess glutamate signaling is involved in cognitive decline. In the hippocampal formation, the dentate gyrus is the most vulnerable to aging and is thought to contribute to age-related cognitive decline. The layer II of the entorhinal cortex is the most vulnerable to neuronal death in Alzheimer's disease. The perforant pathway provides input from the layer II to the dentate gyrus and is one of the earliest affected pathways in Alzheimer's disease. Medial perforant pathway-dentate granule cell synapses are vulnerable to either excess intracellular Zn(2+) or β-amyloid (Aβ)-bound zinc, which induce transient cognitive decline via attenuation of medial perforant pathway LTP. However, it is unknown whether the vulnerability to excess intracellular Zn(2+) is involved in region-specific vulnerability to aging and Alzheimer's disease. To discover a strategy to prevent short-term cognitive decline in normal aging process and the pre-dementia stage of Alzheimer's disease, the present paper deals with vulnerability of medial perforant pathway-dentate granule cell synapses to intracellular Zn(2+) dyshomeostasis and its possible involvement in differential vulnerability to aging and Alzheimer's disease in the hippocampal formation.

  5. 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.

  6. 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.

  7. Dopamine suppresses persistent network activity via D1-like dopamine receptors in rat medial entorhinal cortex

    PubMed Central

    Mayne, Elizabeth W; Craig, Michael T; McBain, Chris J; Paulsen, Ole

    2013-01-01

    Cortical networks display persistent activity in the form of periods of sustained synchronous depolarizations (‘UP states’) punctuated by periods of relative hyperpolarization (‘DOWN states’), which together form the slow oscillation. UP states are known to be synaptically generated and are sustained by a dynamic balance of excitation and inhibition, with fast ionotropic glutamatergic excitatory and GABAergic inhibitory conductances increasing during the UP state. Previously, work from our group demonstrated that slow metabotropic GABA receptors also play an important role in terminating the UP state, but the effects of other neuromodulators on this network phenomenon have received little attention. Given that persistent activity is a neural correlate of working memory and that signalling through dopamine receptors has been shown to be critical for working memory tasks, we examined whether dopaminergic neurotransmission affected the slow oscillation. Here, using an in vitro model of the slow oscillation in rat medial entorhinal cortex, we showed that dopamine strongly and reversibly suppressed cortical UP states. We showed that this effect was mediated through D1-like and not D2-like dopamine receptors, and we found no evidence that tonic dopaminergic transmission affected UP states in our model. PMID:23336973

  8. Nonlinear properties of medial entorhinal cortex neurons reveal frequency selectivity during multi-sinusoidal stimulation.

    PubMed

    Magnani, Christophe; Economo, Michael N; White, John A; Moore, Lee E

    2014-01-01

    The neurons in layer II of the medial entorhinal cortex are part of the grid cell network involved in the representation of space. Many of these neurons are likely to be stellate cells with specific oscillatory and firing properties important for their function. A fundamental understanding of the nonlinear basis of these oscillatory properties is critical for the development of theories of grid cell firing. In order to evaluate the behavior of stellate neurons, measurements of their quadratic responses were used to estimate a second order Volterra kernel. This paper uses an operator theory, termed quadratic sinusoidal analysis (QSA), which quantitatively determines that the quadratic response accounts for a major part of the nonlinearity observed at membrane potential levels characteristic of normal synaptic events. Practically, neurons were probed with multi-sinusoidal stimulations to determine a Hermitian operator that captures the quadratic function in the frequency domain. We have shown that the frequency content of the stimulation plays an important role in the characteristics of the nonlinear response, which can distort the linear response as well. Stimulations with enhanced low frequency amplitudes evoked a different nonlinear response than broadband profiles. The nonlinear analysis was also applied to spike frequencies and it was shown that the nonlinear response of subthreshold membrane potential at resonance frequencies near the threshold is similar to the nonlinear response of spike trains.

  9. GABAergic projections from the medial septum selectively inhibit interneurons in the medial entorhinal cortex.

    PubMed

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

    2014-12-10

    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.

  10. Entorhinal cortex contribution to contextual fear conditioning extinction and reconsolidation in rats.

    PubMed

    Baldi, Elisabetta; Bucherelli, Corrado

    2014-04-01

    During contextual fear conditioning a rat learns a temporal contiguity association between the exposition to a previously neutral context (CS) and an aversive unconditioned stimulus (US) as a footshock. This condition determines in the rat the freezing reaction during the subsequent re-exposition to the context. Potentially the re-exposition without US presentation initiates two opposing and competing processes: reconsolidation and extinction. Reconsolidation process re-stabilizes and strengthens the original memory and it is initiated by a brief re-exposure to context. Instead the extinction process leads to the decrease of the expression of the original memory and it is triggered by prolonged re-exposure to the context. Here we analyzed the entorhinal cortex (ENT) participation in contextual fear conditioning reconsolidation and extinction. The rats were trained in contextual fear conditioning and 24h later they were subjected either to a brief (2 min) reactivation session or to a prolonged (120 min) re-exposition to context to induce extinction of the contextual fear memory. Immediately after the reactivation or the extinction session, the animals were submitted to bilateral ENT TTX inactivation. Memory retention was assessed as conditioned freezing duration measured 72 h after TTX administration. The results showed that ENT inactivation both after reactivation and extinction session was followed by contextual freezing retention impairment. Thus, the present findings point out that ENT is involved in contextual fear memory reconsolidation and extinction. This neural structure might be part of parallel circuits underlying two phases of contextual fear memory processing.

  11. Subthreshold Na+-dependent theta-like rhythmicity in stellate cells of entorhinal cortex layer II

    NASA Astrophysics Data System (ADS)

    Alonso, Angel; Llinás, Rodolfo R.

    1989-11-01

    THE oscillation of membrane potential in mammalian central neurons is of interest because it relates to the role of oscillations in brain function. It has been proposed that the entorhinal cortex (EC), particularly the stellate cells of layer II (ECIIscs), plays an important part in the genesis of the theta rhythm1-3. These neurons occupy a key position in the neocortex-hippocampus-neocortex circuit, a crucial crossroad in memory functions4,5. Neuronal oscillations typically rely on the activation of voltage-dependent Ca2+ conductances and the Ca2+-dependent K+ conductance that usually follows6,7, as seen in other limbic subcortical structures generating theta rhymicity8-10. Here we report, however, that similar oscillations are generated in ECIIscs by a Na+ conductance. The finding of a subthreshold, voltage-gated, Na+-dependent rhythmic membrane oscillation in mammalian neurons indicates that rhythmicity in heterogeneous neuronal networks may be supported by different sets of intrinsic ionic mechanisms in each of the neuronal elements involved.

  12. 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.

  13. The Role of the Human Entorhinal Cortex in a Representational Account of Memory

    PubMed Central

    Schultz, Heidrun; Sommer, Tobias; Peters, Jan

    2015-01-01

    Connectivity studies in animals form the basis for a representational view of medial temporal lobe (MTL) subregions. In this view, distinct subfields of the entorhinal cortex (EC) relay object-related and spatial information from the perirhinal and parahippocampal cortices (PRC, PHC) to the hippocampus (HC). Relatively recent advances in functional magnetic resonance imaging (fMRI) methodology allow examining properties of human EC subregions directly. Antero-lateral and posterior-medial EC subfields show remarkable consistency to their putative rodent and nonhuman primate homologs with regard to intra- and extra-MTL functional connectivity. Accordingly, there is now evidence for a dissociation of object-related vs. spatial processing in human EC subfields. Here, variance in localization may be integrated in the antero-lateral vs. posterior-medial distinction, but may additionally reflect process differences. Functional results in rodents further suggest material-specific representations may be more integrated in EC compared to PRC/PHC. In humans, however, evidence for such a dissociation between EC and PRC/PHC is lacking. Future research may elucidate on the unique contributions of human EC to memory, especially in light of its high degree of intrinsic and extrinsic connectivity. A thorough characterization of EC subfield function may not only advance our understanding of human memory, but also have important clinical implications. PMID:26635581

  14. Increasing Acetylcholine Levels in the Hippocampus or Entorhinal Cortex Reverses the Impairing Effects of Septal GABA Receptor Activation on Spontaneous Alternation

    PubMed Central

    Degroot, Aldemar; Parent, Marise B.

    2000-01-01

    Intra-septal infusions of the γ-aminobutyric acid (GABA) agonist muscimol impair learning and memory in a variety of tasks. This experiment determined whether hippocampal or entorhinal infusions of the acetylcholinesterase inhibitor physostigmine would reverse such impairing effects on spontaneous alternation performance, a measure of spatial working memory. Male Sprague-Dawley rats were given intra-septal infusions of vehicle or muscimol (1 nmole/0.5 μL) combined with unilateral intra-hippocampal or intra-entorhinal infusions of vehicle or physostigmine (10 μg/μL for the hippocampus; 7.5 μg/μL or 1.875 μg/0.25 μL for the entorhinal cortex). Fifteen minutes later, spontaneous alternation performance was assessed. The results indicated that intra-septal infusions of muscimol significantly decreased percentage-of-alternation scores, whereas intra-hippocampal or intra-entorhinal infusions of physostigmine had no effect. More importantly, intra-hippocampal or intra-entorhinal infusions of physostigmine, at doses that did not influence performance when administered alone, completely reversed the impairing effects of the muscimol infusions. These findings indicate that increasing cholinergic levels in the hippocampus or entorhinal cortex is sufficient to reverse the impairing effects of septal GABA receptor activation and support the hypothesis that the impairing effects of septal GABAergic activity involve cholinergic processes in the hippocampus and the entorhinal cortex. PMID:11040261

  15. Precocious development of parvalbumin-like immunoreactive interneurons in the hippocampal formation and entorhinal cortex of the fetal cynomolgus monkey.

    PubMed

    Berger, B; De Grissac, N; Alvarez, C

    1999-01-18

    The calcium-binding protein parvalbumin (PV), a reliable marker of the hippocampal basket and chandelier cells, is first expressed on embryonic day 83 (E83), corresponding to midgestation of the macaque monkey, in restricted hippocampal groups of immature neurons (Berger and Alvarez [1996] J. Comp. Neurol. 366:674-699). In the present study, PV-like immunoreactivity (LIR) was used to follow the further development of this subclass of interneurons. Asynchronous area-specific developmental sequences were observed, predominating initially in the caudal half of the hippocampal formation and the laterocaudal division of the entorhinal cortex and occurring relatively simultaneously in the interconnected hippocampal and entorhinal subfields. Dendritic elongation of PV-like immunoreactive interneurons and perisomatic distribution of PV-like immunoreactive terminal boutons on their cellular targets were first observed in the subiculum around E127; then from E127 to E142 in CA3/CA2 and layers III-V of the entorhinal cortex and, to a lesser extent in CA1, the dentate hilus and deep granule cell layer; and finally from E156 to postnatal day 12 in the rest of the dentate gyrus, the presubiculum and parasubiculum, and layers III-II-I of the entorhinal cortex. These data provide the first indication that a population of basket cells, a major gamma-aminobutyric acid (GABA)ergic component of the hippocampal intrinsic inhibitory circuitry, reaches its cellular targets several weeks before birth in primates in contrast to rodents. The role of the prenatal PV expression in the hippocampal formation of nonhuman primates and whether it coincides with the onset of postsynaptic inhibitory potentials or is accompanied or preceded by a period of gamma-aminobutyric acid-mediated excitatory effects as in rat pups, are crucial questions. They underline the need to pursue direct investigations on primates to be able to legitimately extrapolate the data obtained in rodents.

  16. Cellular resolution optical access to brain regions in fissures: imaging medial prefrontal cortex and grid cells in entorhinal cortex.

    PubMed

    Low, Ryan J; Gu, Yi; Tank, David W

    2014-12-30

    In vivo two-photon microscopy provides the foundation for an array of powerful techniques for optically measuring and perturbing neural circuits. However, challenging tissue properties and geometry have prevented high-resolution optical access to regions situated within deep fissures. These regions include the medial prefrontal and medial entorhinal cortex (mPFC and MEC), which are of broad scientific and clinical interest. Here, we present a method for in vivo, subcellular resolution optical access to the mPFC and MEC using microprisms inserted into the fissures. We chronically imaged the mPFC and MEC in mice running on a spherical treadmill, using two-photon laser-scanning microscopy and genetically encoded calcium indicators to measure network activity. In the MEC, we imaged grid cells, a widely studied cell type essential to memory and spatial information processing. These cells exhibited spatially modulated activity during navigation in a virtual reality environment. This method should be extendable to other brain regions situated within deep fissures, and opens up these regions for study at cellular resolution in behaving animals using a rapidly expanding palette of optical tools for perturbing and measuring network structure and function.

  17. Morphology and kainate-receptor immunoreactivity of identified neurons within the entorhinal cortex projecting to superior temporal sulcus in the cynomolgus monkey

    NASA Technical Reports Server (NTRS)

    Good, P. F.; Morrison, J. H.; Bloom, F. E. (Principal Investigator)

    1995-01-01

    Projections of the entorhinal cortex to the hippocampus are well known from the classical studies of Cajal (Ramon y Cajal, 1904) and Lorente de No (1933). Projections from the entorhinal cortex to neocortical areas are less well understood. Such connectivity is likely to underlie the consolidation of long-term declarative memory in neocortical sites. In the present study, a projection arising in layer V of the entorhinal cortex and terminating in a polymodal association area of the superior temporal gyrus has been identified with the use of retrograde tracing. The dendritic arbors of neurons giving rise to this projection were further investigated by cell filling and confocal microscopy with computer reconstruction. This analysis demonstrated that the dendritic arbor of identified projection neurons was largely confined to layer V, with the exception of a solitary, simple apical dendrite occasionally ascending to superficial laminae but often confined to the lamina dissecans (layer IV). Finally, immunoreactivity for glutamate-receptor subunit proteins GluR 5/6/7 of the dendritic arbor of identified entorhinal projection neurons was examined. The solitary apical dendrite of identified entorhinal projection neurons was prominently immunolabeled for GluR 5/6/7, as was the dendritic arbor of basilar dendrites of these neurons. The restriction of the large bulk of the dendritic arbor of identified entorhinal projection neurons to layer V implies that these neurons are likely to be heavily influenced by hippocampal output arriving in the deep layers of the entorhinal cortex. Immunoreactivity for GluR 5/6/7 throughout the dendritic arbor of such neurons indicates that this class of glutamate receptor is in a position to play a prominent role in mediating excitatory neurotransmission within hippocampal-entorhinal circuits.

  18. Influence of the entorhinal cortex on accumbal and striatal dopaminergic responses in a latent inhibition paradigm.

    PubMed

    Jeanblanc, J; Peterschmitt, Y; Hoeltzel, A; Louilot, A

    2004-01-01

    The use of latent inhibition paradigms is one means of investigating the involvement of mesencephalic dopaminergic (DA) neurons in cognitive processes. We have shown recently that DA neurons reaching the core and the dorsomedial shell parts of the nucleus accumbens and the anterior part of the striatum are differentially involved in latent inhibition. In other respects, theoretical, behavioral and anatomo-functional data suggest that the entorhinal cortex (ENT) may control latent inhibition expression. In this study, using in vivo voltammetry in freely moving rats, we investigated the influence of the ENT on the DA responses obtained in the core and dorsomedial shell parts of the nucleus accumbens and the anterior part of the striatum. For this purpose a reversible inactivation of the left ENT was achieved by the local microinjection of tetrodotoxin, 3 h before pre-exposure to the conditional stimulus (banana odour). During the second session, animals were aversively conditioned to banana odour. Results obtained during the third session (test session), in animals submitted to the reversible blockade of the ENT before the first session were as follows: (1) pre-exposed conditioned animals displayed behavioral aversive responses; (2) where core DA responses were concerned, responses were situated between those observed in pre-exposed and non-pre-exposed conditioned animals; (3) by contrast, where the dorsomedial shell part of the nucleus accumbens and the anterior striatum were concerned, DA variations were not statistically different in pre-exposed and non-pre-exposed conditioned rats. These data suggest that the left ENT exerts a crucial influence over the latent-inhibition-related DA responses in the left dorsomedial shell part of the nucleus accumbens and the left anterior part of the striatum, whereas one or more other brain regions control DA variations in the left core part of the nucleus accumbens. These data may help us to understand the pathophysiology of

  19. Behavioural and electrophysiological studies of entorhinal cortex lesions in the rat.

    PubMed

    Hagan, J J; Verheijck, E E; Spigt, M H; Ruigt, G S

    1992-02-01

    Bilateral ibotenic acid injections aimed at the entorhinal cortex (EC) lesioned the EC and subiculum in 30% of animals (group EC/S) and caused additional hippocampal damage in 50% (group RH). Both lesions increased acetylcholinesterase (AChE) staining in the intermediate molecular layer of the dentate gyrus. EC/S lesions increased diurnal deep sleep and the incidence of spindles but decreased REM sleep. RH lesions increased nocturnal deep sleep and decreased nocturnal quiet sleep. Both lesions reduced power over the theta frequency range from 6-10 Hz for epochs of REM sleep and quiet waking but not deep sleep. Peak frequency was unaffected. The RH group and a subset of the EC/S group were nocturnally, but not diurnally, hyperactive. Six weeks after the lesion there was no evidence for hyperactivity in a novel open field. The EC/S lesion impaired exploration as indicated by reduced motility and rearing in an open field and by the failure of EC/S-lesioned rats to increase contact time in response to a novel olfactory cue. Place navigation learning in a Morris maze was not affected by EC/S or RH lesions. However, when the spatial location of the hidden platform was shifted EC/S-lesioned rats were impaired. The sprouting response, reduced theta power and exploration deficits resemble those reported following electrolytic lesions, but the lack of effect on place navigation learning contrasts with reports of impaired spatial learning following electrolytic lesions. The data prompt a reexamination of the role which the EC projection to the hippocampus plays in spatial learning.

  20. Relative contributions of CA3 and medial entorhinal cortex to memory in rats

    PubMed Central

    O'Reilly, Kally C.; Alarcon, Juan M.; Ferbinteanu, Janina

    2014-01-01

    The hippocampal CA1 field processes spatial information, but the relative importance of intra- vs. extra-hippocampal sources of input into CA1 for spatial behavior is unclear. To characterize the relative roles of these two sources of input, originating in the hippocampal field CA3 and in the medial entorhinal cortex (MEC), we studied effects of discrete neurotoxic lesions of CA3 or MEC on concurrent spatial and nonspatial navigation tasks, and on synaptic transmission in afferents to CA1. Lesions in CA3 or MEC regions that abolished CA3-CA1, or reduced MEC-CA1 synaptic transmission, respectively, impaired spatial navigation and unexpectedly interfered with cue response, suggesting that in certain conditions of training regimen, hippocampal activity may influence behavior otherwise supported by nonhippocampal neural networks. MEC lesions had milder and temporary behavioral effects, but also markedly amplified transmission in the CA3-CA1 pathway. Extensive behavioral training had a similar, but more modest effect on CA3-CA1 transmission. Thus, cortical input to the hippocampus modulates CA1 activity both directly and indirectly, through heterosynaptic interaction, to control information flow in the hippocampal loop. Following damage to hippocampal cortical input, the functional coupling of separate intra- and extra-hippocampal inputs to CA1 involved in normal learning may initiate processes that support recovery of behavioral function. Such a process may explain how CA3 lesions, which do not significantly modify the basic features of CA1 neural activity, nonetheless impair spatial recall, whereas lesions of EC input to CA1, which reduce the spatial selectivity of CA1 firing in foraging rats, have only mild effects on spatial navigation. PMID:25221487

  1. All layers of medial entorhinal cortex receive presubicular and parasubicular inputs.

    PubMed

    Canto, Cathrin B; Koganezawa, Noriko; Beed, Prateep; Moser, Edvard I; Witter, Menno P

    2012-12-05

    The medial entorhinal cortex (MEC), presubiculum (PrS), and parasubiculum (PaS) are interconnected components of the hippocampal-parahippocampal spatial-representation system. Principal cells in all layers of MEC show signs of directional tuning, overt in head direction cells present in all layers except for layer II, and covert in grid cells, which are the major spatially modulated cell type in layer II. Directional information likely originates in the head direction-vestibular system and PrS and PaS are thought to provide this information to MEC. Efferents from PaS and PrS show a selective laminar terminal distribution in MEC superficial layers II and III, respectively. We hypothesized that this anatomically determined laminar distribution does not preclude monosynaptic interaction with neurons located in deeper layers of MEC in view of the extensive apical dendrites from deeper cells reaching layers II and III. This hypothesis was tested in the rat using tilted in vitro slices in which origins and terminations of PrS and PaS fibers were maintained, as assessed using anterograde anatomical tracing. Based on voltage-sensitive dye imaging, multipatch single-cell recordings, and scanning photostimulation of caged glutamate, we report first that principal neurons in all layers of MEC receive convergent monosynaptic inputs from PrS and PaS and second, that elicited responses show layer-specific decay times and frequency-dependent facilitation. These results indicate that regardless of their selective laminar terminal distribution, PrS and PaS inputs may monosynaptically convey directional information to principal neurons in all layers of MEC through synapses on their extensive dendritic arbors.

  2. The entorhinal cortex, but not the dorsal hippocampus, is necessary for single-cue latent learning.

    PubMed

    Stouffer, Eric M

    2010-09-01

    Two experiments were conducted to examine the roles of the entorhinal cortex (EC), dorsal hippocampus (DH), and ventral hippocampus (VH) in a modified Latent Cue Preference (LCP) task. The modified LCP task utilized one visual cue in each compartment, compared to several multimodal cues used in a previous version. In the single-cue LCP task, water-replete rats drink water in one compartment of the LCP box on 1 day, and then have no water in a second compartment of the LCP box the following day (one training trial), for a total of three training trials. Rats are then water-deprived prior to a preference test, in which they are allowed to move freely between the two compartments with the water removed. Latent learning is demonstrated when water-deprived rats spend more time in the compartment that previously contained the water. Experiment 1 demonstrated that the single-cue LCP task results in the same irrelevant-incentive latent learning as the multicue LCP task. In addition, Experiment 1 replicated the finding that a compartment preference based on this latent learning requires a deprivation state during the preference test, while a compartment preference based on conditioning does not. Experiment 2 examined the effects of pretraining neurotoxin lesions of the EC, DH, and VH on this single-cue LCP task. Results showed that lesions of the EC and VH disrupted the irrelevant-incentive latent learning, while lesions of the DH did not. These results indicate that a latent learning task that involves one discrete compartment cue, rather than several compartmental cues, does not require the DH. Therefore, the EC appears to play a central role in single-cue latent learning in the LCP task.

  3. Serotonin increases GABA release in rat entorhinal cortex by inhibiting interneuron TASK-3 K+ channels.

    PubMed

    Deng, Pan-Yue; Lei, Saobo

    2008-10-01

    Whereas the entorhinal cortex (EC) receives profuse serotonergic innervations from the raphe nuclei in the brain stem and is critically involved in the generation of temporal lobe epilepsy, the function of serotonin (5-hydroxytryptamine, 5-HT) in the EC and particularly its roles in temporal lobe epilepsy are still elusive. Here we explored the cellular and molecular mechanisms underlying 5-HT-mediated facilitation of GABAergic transmission and depression of epileptic activity in the superficial layers of the EC. Application of 5-HT increased sIPSC frequency and amplitude recorded from the principal neurons in the EC with no effects on mIPSCs recorded in the presence of TTX. However, 5-HT reduced the amplitude of IPSCs evoked by extracellular field stimulation and in synaptically connected interneuron and pyramidal neuron pairs. Application of 5-HT generated membrane depolarization and increased action potential firing frequency but reduced the amplitude of action potentials in presynaptic interneurons suggesting that 5-HT still increases GABA release whereas the depressant effects of 5-HT on evoked IPSCs could be explained by 5-HT-induced reduction in action potential amplitude. The depolarizing effect of 5-HT was mediated by inhibition of TASK-3 K(+) channels in interneurons and required the functions of 5-HT(2A) receptors and Galpha(q/11) but was independent of phospholipase C activity. Application of 5-HT inhibited low-Mg(2+)-induced seizure activity in slices via 5-HT(1A) and 5-HT(2A) receptors suggesting that 5-HT-mediated depression of neuronal excitability and increase in GABA release contribute to its anti-epileptic effects in the EC.

  4. Cholecystokinin facilitates neuronal excitability in the entorhinal cortex via activation of TRPC-like channels.

    PubMed

    Wang, Shouping; Zhang, An-Ping; Kurada, Lalitha; Matsui, Toshimitsu; Lei, Saobo

    2011-09-01

    Cholecystokinin (CCK) is one of the most abundant neuropeptides in the brain, where it interacts with two G protein-coupled receptors (CCK-1 and CCK-2). Activation of both CCK receptors increases the activity of PLC, resulting in increases in intracellular calcium ion (Ca(2+)) release and activation of PKC. Whereas high density of CCK receptors has been detected in the superficial layers of the entorhinal cortex (EC), the functions of CCK in this brain region have not been determined. Here, we studied the effects of CCK on neuronal excitability of layer III pyramidal neurons in the EC. Our results showed that CCK remarkably increased the firing frequency of action potentials (APs). The effects of CCK on neuronal excitability were mediated via activation of CCK-2 receptors and required the functions of G proteins and PLC. However, CCK-mediated facilitation of neuronal excitability was independent of inositol trisphosphate receptors and PKC. CCK facilitated neuronal excitability by activating a cationic channel to generate membrane depolarization. The effects of CCK were suppressed by the generic, nonselective cationic channel blockers, 2-aminoethyldiphenyl borate and flufenamic acid, but potentiated by gadolinium ion and lanthanum ion at 100 μM. Depletion of extracellular Ca(2+) also counteracted CCK-induced increases in AC firing frequency. Moreover, CCK-induced enhancement of neuronal excitability was inhibited significantly by intracellular application of the antibody to transient receptor potential channel 5 (TRPC5), suggesting the involvement of TRPC5 channels. Our results provide a cellular and molecular mechanism to help explain the functions of CCK in vivo.

  5. Mapping the early development of projections from the entorhinal cortex in the embryonic mouse using prenatal surgery techniques.

    PubMed

    Snyder, D C; Coltman, B W; Muneoka, K; Ide, C F

    1991-12-01

    The purpose of this work was to study the development of specific projections from the postero-lateral cortex during the third trimester of gestation in the mouse. To do this, we labeled undifferentiated lateral cortex with the fluorescent carbocyanine dye, Dil, in the embryonic day (E) 16 mouse embryo using exo utero surgical techniques (Muneoka, Wanek, and Bryant, 1986). Embryos were allowed to develop to term (postnatal day 0, P0) at which time the fiber patterns emanating from the marked regions were studied. Dye placement in the undifferentiated postero-ventral cortex produced labeled fibers in the hippocampal formation. A robust projection of the angular bundle into the CA1 region of the hippocampus was heavily labeled. In addition, in some animals, cortical tracts, such as the anterior commissure, corpus callosum, and a corticotectal tract, were labeled. These tracts have been described previously as scaffolding pathways in the fetal cat (McConnell, Ghosh, and Shatz, 1989), and other vertebrates (Wilson, Ross, Parrett, and Easter, 1990). Dye placement in adjacent, more anterior or dorsal areas showed strong labeling in cortical structures but no labeling in the hippocampal formation. These data indicate that, by birth, the temporal cortex is subdivided along the rostro-caudal axis as entorhinal cortex and perirhinal cortex, and along the dorso-ventral axis, as entorhinal cortex and neocortex. Also, these earliest connections are similar to adult connections in their specificity of target area selection. Therefore, these early, yet specific, connections may play a role int he formation of future connections during postnatal development.

  6. Frequency of subthreshold oscillations at different membrane potential voltages in neurons at different anatomical positions on the dorsoventral axis in the rat medial entorhinal cortex.

    PubMed

    Yoshida, Motoharu; Giocomo, Lisa M; Boardman, Ian; Hasselmo, Michael E

    2011-08-31

    Neurons from layer II of the medial entorhinal cortex show subthreshold membrane potential oscillations (SMPOs) which could contribute to theta-rhythm generation in the entorhinal cortex and to generation of grid cell firing patterns. However, it is unclear whether single neurons have a fixed unique oscillation frequency or whether their frequency varies depending on the mean membrane potential in a cell. We therefore examined the frequency of SMPOs at different membrane potentials in layer II stellate-like cells of the rat medial entorhinal cortex in vitro. Using whole-cell patch recordings, we found that the fluctuations in membrane potential show a broad band of low power frequencies near resting potential that transition to more narrowband oscillation frequencies with depolarization. The transition from broadband to narrowband frequencies depends on the location of the neuron along the dorsoventral axis in the entorhinal cortex, with dorsal neurons transitioning to higher-frequency oscillations relative to ventral neurons transitioning to lower-frequency oscillations. Once SMPOs showed a narrowband frequency, systematic frequency changes were not observed with further depolarization. Using a Hodgkin-Huxley-style model of membrane currents, we show that differences in the influence of depolarization on the frequency of SMPOs at different dorsal to ventral positions could arise from differences in the properties of the h current. The properties of frequency changes in this data are important for evaluating models of the generation of grid cell firing fields with different spacings along the dorsal-to-ventral axis of medial entorhinal cortex.

  7. Loss of entorhinal cortex and hippocampal volumes compared to whole brain volume in normal aging: the SMART-Medea study.

    PubMed

    Knoops, Arnoud J G; Gerritsen, Lotte; van der Graaf, Yolanda; Mali, Willem P T M; Geerlings, Mirjam I

    2012-07-30

    In non-demented elderly age-related decline in hippocampal volume has often been observed, but it is not clear if this loss is disproportionate relative to other brain tissue. Few studies examined age-related volume loss of the entorhinal cortex. We investigated the association of age with hippocampal and entorhinal cortex (ERC) volumes in a large sample of middle-aged and older persons without dementia. Within the SMART-Medea study, cross-sectional analyses were performed in 453 non-demented subjects (mean age 62±9 years, 81% male) with a history of arterial disease. Hippocampal and ERC volumes were assessed by manual segmentation on three-dimensional fast field-echo sequence T1-weighted magnetic resonance images. Automated segmentation was used to quantify volumes of BV and ICV. Hippocampal and ERC volumes were divided by intracranial volume (ICV) as well as total brain volume (BV) to determine whether age-related differences were disproportionate relative to other brain tissue. Total crude hippocampal volume was 5.96±0.7 ml and total crude ERC volume was 0.34±0.06 ml. Linear regression analyses adjusted for sex showed that with increasing age, hippocampal volume divided by ICV decreased (B per year older=-0.01 ml; 95% CI -0.02 to -0.004). However, no age-related decline in hippocampal volume relative to BV was observed (B per year older=0.005 ml; 95% CI -0.002 to 0.01). No age-related decline in ERC volume relative to ICV or BV was observed. In this population of nondemented patients with a history of vascular disease no age-related decline in entorhinal cortex volume was observed and although hippocampal volume decreased with age, it was not disproportionate relative to total brain volume.

  8. 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.

  9. BDNF and trkB mRNA expression in the rat hippocampus following entorhinal cortex lesions.

    PubMed

    Lapchak, P A; Araujo, D M; Hefti, F

    1993-02-01

    Quantitative in situ hybridization was used to determine whether the prevalence or topographical distribution of brain-derived neurotrophic factor (BDNF) or tyrosine receptor kinase (trk) B mRNA is altered in the hippocampal formation following lesions of excitatory afferents from the entorhinal cortex which provides an external source of innervation for the hippocampal formation. BDNF mRNA levels were not altered in the hippocampal formation up to 10 days following entorhinal cortex lesions (ECLs). The levels of mRNA coding for all known forms of trkB receptors also remained unchanged. The prevalence of the synaptic plasticity marker SNAP-25 mRNA was increased in the CA2 and CA3 pyramidal cell layers and the dentate gyrus by 6 days following ECLs and remained elevated at 10 days following ECLs. Our findings indicate that hippocampal neuron sprouting which occurs in response to ECLs is not the result of changes in the expression of the BDNF or trkB mRNA.

  10. Highest trkB mRNA expression in the entorhinal cortex among hippocampal subregions in the adult rat: contrasting pattern with BDNF mRNA expression.

    PubMed

    Tokuyama, W; Hashimoto, T; Li, Y X; Okuno, H; Miyashita, Y

    1998-11-20

    Brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, regulate synaptic functions in the hippocampus of the adult rodent. In previous studies, in situ hybridization methods have been used to evaluate regional differences in BDNF and trkB mRNA expression levels in hippocampal subregions. However, these studies have failed to reach consensus regarding the regional differences in the mRNA expression levels. In the present study, we quantitated mRNA expression levels using two different methods, ribonuclease protection assays and a quantitative reverse-transcription polymerase chain reaction technique, in four hippocampal subregions: the entorhinal cortex, dentate gyrus (DG), CA3 and CA1. These two methods yielded the same results. We found that BDNF and trkB mRNA expression levels did not covary in the four subregions. BDNF and full length trkB (trkB FL) mRNA in the entorhinal cortex and the DG show contrasting expression patterns. The expression level of BDNF mRNA was highest in the DG among the hippocampal subregions and low in the entorhinal cortex and the CA1, whereas the trkB FL mRNA expression level was highest in the entorhinal cortex, low in the DG and lowest in the CA3. These results suggest regional differences in BDNF/TrkB signaling for maintenance and modifiability of neuronal connections in the hippocampal formation.

  11. Differential Contribution of Kainate Receptors to EPSCs in Superficial Layer Neurons of the Rat Medial Entorhinal Cortex

    PubMed Central

    West, Peter J.; Dalpé-Charron, Alexandre; Wilcox, Karen S.

    2009-01-01

    Although in situ hybridization studies have revealed the presence of kainate receptor (KAR) mRNA in neurons of the rat medial entorhinal cortex (mEC), the functional presence and roles of these receptors are only beginning to be examined. To address this deficiency, whole cell voltage clamp recordings of locally evoked EPSCs were made from mEC layer II and III neurons in combined entorhinal cortex -hippocampal brain slices. Three types of neurons were identified by their electroresponsive membrane properties, locations, and morphologies: stellate-like “Sag” neurons in layer II (S), pyramidal-like “No Sag” neurons in layer III (NS), and “Intermediate Sag” neurons with varied morphologies and locations (IS). Non-NMDA EPSCs in these neurons were composed of two components, and the slow decay component in NS neurons had larger amplitudes and contributed more to the combined EPSC than did those observed in S and IS neurons. This slow component was mediated by KARs and was characterized by its resistance to either GYKI 52466 (100 μM) or NBQX (1 μM), relatively slow decay kinetics, and sensitivity to CNQX (10–50 μM). KAR mediated EPSCs in pyramidal-like NS neurons contributed significantly more to the combined non-NMDA EPSC than did those from S and IS neurons. Layer III neurons of the mEC are selectively susceptible to degeneration in human temporal lobe epilepsy (TLE) and animal models of TLE such as kainate-induced status epilepticus. Characterizing differences in the complement of postsynaptic receptors expressed in injury prone versus injury resistant mEC neurons represents an important step toward understanding the vulnerability of layer III neurons seen in TLE. PMID:17395391

  12. 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.

  13. 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.

  14. Cell Type-Specific Differences in Spike Timing and Spike Shape in the Rat Parasubiculum and Superficial Medial Entorhinal Cortex.

    PubMed

    Ebbesen, Christian Laut; Reifenstein, Eric Torsten; Tang, Qiusong; Burgalossi, Andrea; Ray, Saikat; Schreiber, Susanne; Kempter, Richard; Brecht, Michael

    2016-07-26

    The medial entorhinal cortex (MEC) and the adjacent parasubiculum are known for their elaborate spatial discharges (grid cells, border cells, etc.) and the precessing of spikes relative to the local field potential. We know little, however, about how spatio-temporal firing patterns map onto cell types. We find that cell type is a major determinant of spatio-temporal discharge properties. Parasubicular neurons and MEC layer 2 (L2) pyramids have shorter spikes, discharge spikes in bursts, and are theta-modulated (rhythmic, locking, skipping), but spikes phase-precess only weakly. MEC L2 stellates and layer 3 (L3) neurons have longer spikes, do not discharge in bursts, and are weakly theta-modulated (non-rhythmic, weakly locking, rarely skipping), but spikes steeply phase-precess. The similarities between MEC L3 neurons and MEC L2 stellates on one hand and parasubicular neurons and MEC L2 pyramids on the other hand suggest two distinct streams of temporal coding in the parahippocampal cortex.

  15. Cholinergic receptor activation induces a relative facilitation of synaptic responses in the entorhinal cortex during theta- and gamma-frequency stimulation of parasubicular inputs.

    PubMed

    Sparks, D W; Chapman, C A

    2013-01-29

    The parasubiculum sends its single major output to layer II of the entorhinal cortex, and it may therefore interact with inputs to the entorhinal cortex from other cortical areas, and help to shape the activity of layer II entorhinal cells that project to the hippocampal formation. Cholinergic inputs are thought to contribute to the generation of theta- and gamma-frequency activities in the parasubiculum and entorhinal cortex, and the present study assessed how cholinergic receptor activation affects synaptic responses of the entorhinal cortex to theta- and gamma-frequency stimulation. Depth profiles of field excitatory postsynaptic potentials (fEPSPs) in acute brain slices showed a short-latency negative fEPSP in layer II, consistent with the activation of excitatory synaptic inputs to layer II. Application of the cholinergic agonist carbachol (CCh) suppressed synaptic responses and enhanced paired-pulse facilitation. CCh also resulted in a marked relative facilitation of synaptic responses evoked during short 5-pulse trains of stimulation at both theta- and gamma-frequencies. Application of the M(1) antagonist pirenzepine, but not the M(2) antagonist methoctramine, blocked the facilitation of responses. Inhibition of the M-current or block of GABA(B) receptors had no effect, but the facilitation effect was partially blocked by the N-methyl-d-aspartate (NMDA) antagonist APV, indicating that NMDA receptors play a role. Application of ZD7288, a selective inhibitor of the hyperpolarization-activated cationic current I(h), almost completely blocked the relative facilitation of responses, and the less potent I(h)-blocker Cs(+) also resulted in a partial block. The relative facilitation of synaptic responses induced by CCh is therefore likely mediated by multiple mechanisms including the cholinergic suppression of transmitter release that enhances transmitter availability during repetitive stimulation, NMDA receptor-mediated effects on pre- or postsynaptic function, and

  16. 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

  17. Synaptic remodeling in the dentate gyrus, CA3, CA1, subiculum, and entorhinal cortex of mice: effects of deprived rearing and voluntary running.

    PubMed

    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.

  18. Distribution of the receptor-anchoring protein gephyrin in the rat dentate gyrus and changes following entorhinal cortex lesion.

    PubMed

    Simbürger, E; Plaschke, M; Kirsch, J; Nitsch, R

    2000-04-01

    We analyzed the distribution of the receptor-anchoring protein gephyrin in the normal and deafferented rat dentate gyrus to investigate whether the expression of this postsynaptic protein is altered in response to the formation of new synaptic contacts. Confocal microscopy and digital image analysis revealed that in normal dentate gyrus immunolabeling was most prominent in the outer molecular layer and decreased successively in the direction of the granule cell layer. Simultaneous immunolabeling for gephyrin and cell-specific markers showed that granule cells and parvalbumin-positive interneurons express gephyrin. Large, intensely stained, gephyrin-positive clusters were distributed along distinct dendrites, and most of them were positive for parvalbumin. Calbindin-immunostained dendrites were associated with smaller, gephyrin-positive clusters. Lesion of the medial entorhinal cortex leads to deafferentiation of the middle molecular layer which resulted in an increased gephyrin immunoreactivity. These changes were due to a significantly increased concentration of the very small gephyrin-positive clusters. Parvalbumin-positive dendrites did not display any increase in co-localizing gephyrin-positive structures. The altered immunolabeling pattern persisted until 12 weeks after lesion, a time when the process of synaptic reorganization is complete. Our findings suggest that synaptogenesis following deafferentiation results in a cell-specific redistribution of gephyrin immunoreactivity at specific inhibitory synapses.

  19. DHA Improves Cognition and Prevents Dysfunction of Entorhinal Cortex Neurons in 3xTg-AD Mice

    PubMed Central

    Arsenault, Dany; Julien, Carl; Tremblay, Cyntia; Calon, Frédéric

    2011-01-01

    Defects in neuronal activity of the entorhinal cortex (EC) are suspected to underlie the symptoms of Alzheimer's disease (AD). Whereas neuroprotective effects of docosahexaenoic acid (DHA) have been described, the effects of DHA on the physiology of EC neurons remain unexplored in animal models of AD. Here, we show that DHA consumption improved object recognition (↑12%), preventing deficits observed in old 3xTg-AD mice (↓12%). Moreover, 3xTg-AD mice displayed seizure-like akinetic episodes, not detected in NonTg littermates and partly prevented by DHA (↓50%). Patch-clamp recording revealed that 3xTg-AD EC neurons displayed (i) loss of cell capacitance (CC), suggesting reduced membrane surface area; (ii) increase of firing rate versus injected current (F-I) curve associated with modified action potentials, and (iii) overactivation of glutamatergic synapses, without changes in synaptophysin levels. DHA consumption increased CC (↑12%) and decreased F-I slopes (↓21%), thereby preventing the opposite alterations observed in 3xTg-AD mice. Our results indicate that cognitive performance and basic physiology of EC neurons depend on DHA intake in a mouse model of AD. PMID:21383850

  20. State-dependent modulation of amygdala inputs by dopamine-induced enhancement of sodium currents in layer V entorhinal cortex.

    PubMed

    Rosenkranz, J Amiel; Johnston, Daniel

    2007-06-27

    Interaction between the entorhinal cortex (EC) and basolateral amygdala (BLA) may be a fundamental component in the consolidation of many forms of affective memory, such as inhibitory avoidance. Dopamine (DA) in the EC is necessary for, and may facilitate, this form of learning. This effect of DA on affective behaviors may be accomplished in part through modulation of amygdala inputs. Although it is known that DA can modulate neuronal activity in the EC, it is not known whether DA modulates inputs from the BLA. In this study, we used in vitro patch-clamp recordings and Ca2+ imaging of layer V neurons in the rat lateral EC to determine whether DA modulates the integration of inputs from the BLA and the mechanism for this modulation. We found that DA exerted actions that depended on the neuronal state. Near resting membrane potentials, DA suppressed integration of inputs, whereas at depolarized potentials, DA enhanced integration. DA enhanced the integration by a D2-mediated enhancement of Na+ currents, via phospholipase C. These experiments demonstrate that DA can exert actions in the EC that depend on the membrane voltage. This effect of DA may affect a wide range of inputs. Functionally, by enhancement of amygdala inputs that arrive in concert with other inputs, or during depolarized states, DA can facilitate the impact of affect on memory in a subset of conditions.

  1. Distant Space Processing is Controlled by tPA-dependent NMDA Receptor Signaling in the Entorhinal Cortex.

    PubMed

    Hébert, Marie; Anfray, Antoine; Chevilley, Arnaud; Martinez de Lizarrondo, Sara; Quenault, Aurélien; Louessard, Morgane; Roussel, Benoit D; Obiang, Pauline; Save, Etienne; Orset, Cyrille; Maubert, Eric; Vivien, Denis; Agin, Véronique

    2016-09-09

    In humans, spatial cognition and navigation impairments are a frequent situation during physiological and pathological aging, leading to a dramatic deterioration in the quality of life. Despite the discovery of neurons with location-specific activity in rodents, that is, place cells in the hippocampus and later on grid cells in the entorhinal cortex (EC), the molecular mechanisms underlying spatial cognition are still poorly known. Our present data bring together in an unusual combination 2 molecules of primary biological importance: a major neuronal excitatory receptor, N-methyl-D-aspartate receptor (NMDAR), and an extracellular protease, tissue plasminogen activator (tPA), in the control of spatial navigation. By using tPA-deficient mice and a structure-selective pharmacological approach, we demonstrate that the tPA-dependent NMDAR signaling potentiation in the EC plays a key and selective role in the encoding and the subsequent use of distant landmarks during spatial learning. We also demonstrate that this novel function of tPA in the EC is reduced during aging. Overall, these results argue for the concept that encoding of proximal versus distal landmarks is mediated not only by different anatomical pathways but also by different molecular mechanisms, with the tPA-dependent potentiation of NMDAR signaling in the EC that plays an important role.

  2. Entorhinal Cortex dysfunction can be rescued by inhibition of microglial RAGE in an Alzheimer’s disease mouse model

    PubMed Central

    Criscuolo, Chiara; Fontebasso, Veronica; Middei, Silvia; Stazi, Martina; Ammassari-Teule, Martine; Yan, Shirley ShiDu; Origlia, Nicola

    2017-01-01

    The Entorhinal cortex (EC) has been implicated in the early stages of Alzheimer’s disease (AD). In particular, spreading of neuronal dysfunction within the EC-Hippocampal network has been suggested. We have investigated the time course of EC dysfunction in the AD mouse model carrying human mutation of amyloid precursor protein (mhAPP) expressing human Aβ. We found that in mhAPP mice plasticity impairment is first observed in EC superficial layer and further affected with time. A selective impairment of LTP was observed in layer II horizontal connections of EC slices from 2 month old mhAPP mice, whereas at later stage of neurodegeneration (6 month) basal synaptic transmission and LTD were also affected. Accordingly, early synaptic deficit in the mhAPP mice were associated with a selective impairment in EC-dependent associative memory tasks. The introduction of the dominant-negative form of RAGE lacking RAGE signalling targeted to microglia (DNMSR) in mhAPP mice prevented synaptic and behavioural deficit, reducing the activation of stress related kinases (p38MAPK and JNK). Our results support the involvement of the EC in the development and progression of the synaptic and behavioural deficit during amyloid-dependent neurodegeneration and demonstrate that microglial RAGE activation in presence of Aβ-enriched environment contributes to the EC vulnerability. PMID:28205565

  3. Fimbria-fornix and entorhinal cortex differential contribution to contextual and cued fear conditioning consolidation in rats.

    PubMed

    Baldi, Elisabetta; Liuzzo, Antonino; Bucherelli, Corrado

    2013-04-10

    The Fimbria-Fornix (FF) and Entorhinal Cortex (EC) are the primary interfaces between the hippocampus and, respectively, subcortical structures and cortical areas. Their mnemonic role has been repeatedly proposed. In order to investigate their role in fear conditioning, FF and EC were subjected to bilateral fully reversible tetrodotoxin (TTX) inactivation during consolidation in adult male Wistar rats that had undergone training for fear conditioning to an acoustic stimulus (CS) and context. TTX was stereotaxically injected into animals of different groups at increasing post-acquisition delays. Memory was assessed as conditioned freezing duration measured during retention testing, performed 72 and 96 h after TTX administration in a counterbalanced manner. The results showed that FF inactivation, performed immediately after conditioning, did not disrupt consolidation of either contextual or auditory fear memory. On the contrary, EC inactivation performed at the same time was followed by both contextual and CS fear response retention impairment. EC inactivation performed 1.5h post-acquisition impaired only contextual fear response retention. EC inactivation performed 24h after acquisition training had no effect on the consolidation process. The present findings show a clearly different role of FF and EC in fear conditioning consolidation in the rat. The results are discussed in relation to their known connections with the hippocampus.

  4. Visual landmarks sharpen grid cell metric and confer context specificity to neurons of the medial entorhinal cortex

    PubMed Central

    Pérez-Escobar, José Antonio; Kornienko, Olga; Latuske, Patrick; Kohler, Laura; Allen, Kevin

    2016-01-01

    Neurons of the medial entorhinal cortex (MEC) provide spatial representations critical for navigation. In this network, the periodic firing fields of grid cells act as a metric element for position. The location of the grid firing fields depends on interactions between self-motion information, geometrical properties of the environment and nonmetric contextual cues. Here, we test whether visual information, including nonmetric contextual cues, also regulates the firing rate of MEC neurons. Removal of visual landmarks caused a profound impairment in grid cell periodicity. Moreover, the speed code of MEC neurons changed in darkness and the activity of border cells became less confined to environmental boundaries. Half of the MEC neurons changed their firing rate in darkness. Manipulations of nonmetric visual cues that left the boundaries of a 1D environment in place caused rate changes in grid cells. These findings reveal context specificity in the rate code of MEC neurons. DOI: http://dx.doi.org/10.7554/eLife.16937.001 PMID:27449281

  5. Pyramidal and stellate cell specificity of grid and border representations in layer 2 of medial entorhinal cortex.

    PubMed

    Tang, Qiusong; Burgalossi, Andrea; Ebbesen, Christian Laut; Ray, Saikat; Naumann, Robert; Schmidt, Helene; Spicher, Dominik; Brecht, Michael

    2014-12-17

    In medial entorhinal cortex, layer 2 principal cells divide into pyramidal neurons (mostly calbindin positive) and dentate gyrus-projecting stellate cells (mostly calbindin negative). We juxtacellularly labeled layer 2 neurons in freely moving animals, but small sample size prevented establishing unequivocal structure-function relationships. We show, however, that spike locking to theta oscillations allows assigning unidentified extracellular recordings to pyramidal and stellate cells with ∼83% and ∼89% specificity, respectively. In pooled anatomically identified and theta-locking-assigned recordings, nonspatial discharges dominated, and weakly hexagonal spatial discharges and head-direction selectivity were observed in both cell types. Clear grid discharges were rare and mostly classified as pyramids (19%, 19/99 putative pyramids versus 3%, 3/94 putative stellates). Most border cells were classified as stellate (11%, 10/94 putative stellates versus 1%, 1/99 putative pyramids). Our data suggest weakly theta-locked stellate border cells provide spatial input to dentate gyrus, whereas strongly theta-locked grid discharges occur mainly in hexagonally arranged pyramidal cell patches and do not feed into dentate gyrus.

  6. Gastrodin Suppresses the Amyloid β-Induced Increase of Spontaneous Discharge in the Entorhinal Cortex of Rats

    PubMed Central

    Chen, Peng-zhi; Jiang, Hui-hui; Wen, Bo; Ren, Shuan-cheng; Chen, Yang; Ji, Wei-gang; Hu, Bo; Zhang, Jun; Xu, Fenglian; Zhu, Zhi-ru

    2014-01-01

    Accumulated soluble amyloid beta- (Aβ-) induced aberrant neuronal network activity may directly contribute to cognitive deficits, which are the most outstanding characteristics of Alzheimer's disease (AD). The entorhinal cortex (EC) is one of the earliest affected brain regions in AD. Impairments of EC neurons are responsible for the cognitive deficits in AD. However, little effort has been made to investigate the effects of soluble Aβ on the discharge properties of EC neurons in vivo. The present study was designed to examine the effects of soluble Aβ1−42 on the discharge properties of EC neurons, using in vivo extracellular single unit recordings. The protective effects of gastrodin (GAS) were also investigated against Aβ1−42-induced alterations in EC neuronal activities. The results showed that the spontaneous discharge of EC neurons was increased by local application of soluble Aβ1−42 and that GAS can effectively reverse Aβ1−42-induced facilitation of spontaneous discharge in a concentration-dependent manner. Moreover, whole-cell patch clamp results indicated that the protective function of GAS on abnormal hyperexcitability may be partially mediated by its inhibitory action on Aβ1−42-elicited inward currents in EC neurons. Our study suggested that GAS may provide neuroprotective effects on Aβ1−42-induced hyperactivity in EC neurons of rats. PMID:25485157

  7. Activation of Phosphatidylinositol-Linked Dopamine Receptors Induces a Facilitation of Glutamate-Mediated Synaptic Transmission in the Lateral Entorhinal Cortex

    PubMed Central

    Glovaci, Iulia; Chapman, C. Andrew

    2015-01-01

    The lateral entorhinal cortex receives strong inputs from midbrain dopamine neurons that can modulate its sensory and mnemonic function. We have previously demonstrated that 1 µM dopamine facilitates synaptic transmission in layer II entorhinal cortex cells via activation of D1-like receptors, increased cAMP-PKA activity, and a resulting enhancement of AMPA-receptor mediated currents. The present study assessed the contribution of phosphatidylinositol (PI)-linked D1 receptors to the dopaminergic facilitation of transmission in layer II of the rat entorhinal cortex, and the involvement of phospholipase C activity and release of calcium from internal stores. Whole-cell patch-clamp recordings of glutamate-mediated evoked excitatory postsynaptic currents were obtained from pyramidal and fan cells. Activation of D1-like receptors using SKF38393, SKF83959, or 1 µM dopamine induced a reversible facilitation of EPSCs which was abolished by loading cells with either the phospholipase C inhibitor U-73122 or the Ca2+ chelator BAPTA. Neither the L-type voltage-gated Ca2+ channel blocker nifedipine, nor the L/N-type channel blocker cilnidipine, blocked the facilitation of synaptic currents. However, the facilitation was blocked by blocking Ca2+ release from internal stores via inositol 1,4,5-trisphosphate (InsP3) receptors or ryanodine receptors. Follow-up studies demonstrated that inhibiting CaMKII activity with KN-93 failed to block the facilitation, but that application of the protein kinase C inhibitor PKC(19-36) completely blocked the dopamine-induced facilitation. Overall, in addition to our previous report indicating a role for the cAMP-PKA pathway in dopamine-induced facilitation of synaptic transmission, we demonstrate here that the dopaminergic facilitation of synaptic responses in layer II entorhinal neurons also relies on a signaling cascade dependent on PI-linked D1 receptors, PLC, release of Ca2+ from internal stores, and PKC activation which is likely dependent

  8. Contrasting patterns of receptive field plasticity in the hippocampus and the entorhinal cortex: an adaptive filtering approach.

    PubMed

    Frank, Loren M; Eden, Uri T; Solo, Victor; Wilson, Matthew A; Brown, Emery N

    2002-05-01

    Neural receptive fields are frequently plastic: a neural response to a stimulus can change over time as a result of experience. We developed an adaptive point process filtering algorithm that allowed us to estimate the dynamics of both the spatial receptive field (spatial intensity function) and the interspike interval structure (temporal intensity function) of neural spike trains on a millisecond time scale without binning over time or space. We applied this algorithm to both simulated data and recordings of putative excitatory neurons from the CA1 region of the hippocampus and the deep layers of the entorhinal cortex (EC) of awake, behaving rats. Our simulation results demonstrate that the algorithm accurately tracks simultaneous changes in the spatial and temporal structure of the spike train. When we applied the algorithm to experimental data, we found consistent patterns of plasticity in the spatial and temporal intensity functions of both CA1 and deep EC neurons. These patterns tended to be opposite in sign, in that the spatial intensity functions of CA1 neurons showed a consistent increase over time, whereas those of deep EC neurons tended to decrease, and the temporal intensity functions of CA1 neurons showed a consistent increase only in the "theta" (75-150 msec) region, whereas those of deep EC neurons decreased in the region between 20 and 75 msec. In addition, the minority of deep EC neurons whose spatial intensity functions increased in area over time fired in a significantly more spatially specific manner than non-increasing deep EC neurons. We hypothesize that this subset of deep EC neurons may receive more direct input from CA1 and may be part of a neural circuit that transmits information about the animal's location to the neocortex.

  9. Temporal Lobe Epilepsy Induces Intrinsic Alterations in Na Channel Gating in Layer II Medial Entorhinal Cortex Neurons

    PubMed Central

    Hargus, Nicholas J.; Merrick, Ellen C.; Nigam, Aradhya; Kalmar, Christopher L.; Baheti, Aparna R.; Bertram, Edward H.; Patel, Manoj K.

    2010-01-01

    Temporal lobe epilepsy (TLE) is the most common form of adult epilepsy involving the limbic structures of the temporal lobe. Layer II neurons of the entorhinal cortex (EC) form the major excitatory input into the hippocampus via the perforant path and consist of non-stellate and stellate neurons. These neurons are spared and hyper-excitable in TLE. The basis for the hyper-excitability is likely multifactorial and may include alterations in intrinsic properties. In a rat model of TLE, medial EC (mEC) non-stellate and stellate neurons had significantly higher action potential (AP) firing frequencies than in control. The increase remained in the presence of synaptic blockers, suggesting intrinsic mechanisms. Since sodium (Na) channels play a critical role in AP generation and conduction we sought to determine if Na channel gating parameters and expression levels were altered in TLE. Na channel currents recorded from isolated mEC TLE neurons revealed increased Na channel conductances, depolarizing shifts in inactivation parameters and larger persistent (INaP) and resurgent (INaR) Na currents. Immunofluorescence experiments revealed increased staining of Nav1.6 within the axon initial segment and Nav1.2 within the cell bodies of mEC TLE neurons. These studies provide support for additional intrinsic alterations within mEC layer II neurons in TLE and implicate alterations in Na channel activity and expression, in part, for establishing the profound increase in intrinsic membrane excitability of mEC layer II neurons in TLE. These intrinsic changes, together with changes in the synaptic network, could support seizure activity in TLE. PMID:20946956

  10. Differential role of muscarinic transmission within the entorhinal cortex and basolateral amygdala in the processing of irrelevant stimuli.

    PubMed

    Barak, Segev; Weiner, Ina

    2010-04-01

    Cholinergic projections to the entorhinal cortex (EC) and basolateral amygdala (BLA) mediate distinct cognitive processes through muscarinic acetylcholine receptors (mAChRs). In this study, we sought to further differentiate the role of muscarinic transmission in these regions in cognition, using the latent inhibition (LI) phenomenon. LI is a cross-species phenomenon manifested as poorer conditioning to a stimulus experienced as irrelevant during an earlier stage of repeated non-reinforced pre-exposure to that stimulus, and is considered to index the ability to ignore, or to in-attend to, irrelevant stimuli. Given our recent findings that systemic administration of the mAChR antagonist scopolamine can produce two contrasting LI abnormalities in rats, ie, abolish LI under conditions yielding LI in non-treated controls, or produce abnormally persistent LI under conditions preventing its expression in non-treated controls, we tested whether mAChR blockade in the EC and BLA would induce LI abolition and persistence, respectively. We found that intra-EC scopolamine infusion (1, 10 mug per hemisphere) abolished LI when infused in pre-exposure or both pre-exposure and conditioning, but not in conditioning alone, whereas intra-BLA scopolamine infusion led to persistent LI when infused in conditioning or both stages, but not in pre-exposure alone. Although cholinergic innervation of the EC and BLA has long been implicated in attention to novel stimuli and in processing of motivationally significant stimuli, respectively, our results provide evidence that EC mAChRs also have a role in the development of inattention to stimuli, whereas BLA mAChRs have a role in re-attending to previously irrelevant stimuli that became motivationally relevant.

  11. Defects in the medial entorhinal cortex and dentate gyrus in the mouse model of Sanfilippo syndrome type B.

    PubMed

    Ohmi, Kazuhiro; Zhao, Hui-Zhi; Neufeld, Elizabeth F

    2011-01-01

    Sanfilippo syndrome type B (MPS IIIB) is characterized by profound mental retardation in childhood, dementia and death in late adolescence; it is caused by deficiency of α-N-acetylglucosaminidase and resulting lysosomal storage of heparan sulfate. A mouse model, generated by homologous recombination of the Naglu gene, was used to study pathological changes in the brain. We found earlier that neurons in the medial entorhinal cortex (MEC) and the dentate gyrus showed a number of secondary defects, including the presence of hyperphosphorylated tau (Ptau) detected with antibodies raised against Ptau in Alzheimer disease brain. By further use of immunohistochemistry, we now show staining in neurons of the same area for beta amyloid, extending the resemblance to Alzheimer disease. Ptau inclusions in the dentate gyrus of MPS IIIB mice were reduced in number when the mice were administered LiCl, a specific inhibitor of Gsk3β. Additional proteins found elevated in MEC include proteins involved in autophagy and the heparan sulfate proteoglycans, glypicans 1 and 5, the latter closely related to the primary defect. The level of secondary accumulations was associated with elevation of glypican, as seen by comparing brains of mice at different ages or with different mucopolysaccharide storage diseases. The MEC of an MPS IIIA mouse had the same intense immunostaining for glypican 1 and other markers as MPS IIIB, while MEC of MPS I and MPS II mice had weak staining, and MEC of an MPS VI mouse had no staining at all for the same proteins. A considerable amount of glypican was found in MEC of MPS IIIB mice outside of lysosomes. We propose that it is the extralysosomal glypican that would be harmful to neurons, because its heparan sulfate branches could potentiate the formation of Ptau and beta amyloid aggregates, which would be toxic as well as difficult to degrade.

  12. Reversible inactivation of the entorhinal cortex disrupts the establishment and expression of latent inhibition of cued fear conditioning in C57BL/6 mice.

    PubMed

    Lewis, Michael C; Gould, Thomas J

    2007-01-01

    For latent inhibition, preexposure to a conditioned stimulus (CS) prior to training with an unconditioned stimulus (US) results in decreased conditioned responses (CRs) to the CS at the time of testing. The mechanism by which decreased CRs occurs, however, is unknown; CS preexposure may interfere with subsequent conditioning, or modulate the expression of CRs. Previous research has suggested that the entorhinal cortex (EC) is necessary for latent inhibition of a variety of tasks. However, no studies have specifically compared the role of the EC in acquisition vs. expression of latent inhibition. The present study used reversible inactivation of the EC to address this issue. The GABA agonist muscimol (0.5 microg/side) was directly infused into the EC of mice prior to CS preexposure, training, or testing. Our results indicate that muscimol inactivation of the EC before CS preexposure disrupts latent inhibition of cued fear conditioning. Importantly, this same dose of muscimol did not disrupt cued fear conditioning, nor did it affect latent inhibition when infused into the subiculum. Furthermore, inactivation of the EC at testing disrupted the expression of latent inhibition of cued fear conditioning; that is, CS preexposed mice that received entorhinal cortical muscimol infusion at testing showed CRs compared to saline-infused CS preexposed mice. These findings suggest that repeated preexposure to the CS during latent inhibition may alter entorhinal cortical activity thereby allowing the EC to exert inhibitory control over the expression of CRs during testing of CS preexposed mice.

  13. Calretinin in the entorhinal cortex of the rat: distribution, morphology, ultrastructure of neurons, and co-localization with gamma-aminobutyric acid and parvalbumin.

    PubMed

    Wouterlood, F G; van Denderen, J C; van Haeften, T; Witter, M P

    2000-09-18

    Calretinin is a marker that differentially labels neurons in the central nervous system. We used this marker to distinguish subtypes of neurons within the general population of neurons in the entorhinal cortex of the rat. The distribution, morphology, and ultrastructure of calretinin-immunopositive neurons in this cortical area were documented. We further analyzed the co-localization of the marker with gamma-aminobutyric acid (GABA) and studied whether calretinin-positive neurons project to the hippocampal formation. Methods used included single-label immunocytochemistry at the light and electron microscopic level, retrograde tracing combined with immunocytochemistry, and double-label confocal laser scanning microscopy (CLSM). The entorhinal cortex contained calretinin-positive cells in a scattered fashion, in all layers except layer IV (lamina dissecans). Bipolar and multipolar dendritic configurations were present, displaying smooth dendrites. Bipolar cells had a uniform morphology whereas the multipolar calretinin cell population consisted of large neurons, cells with long ascending dendrites, horizontally oriented neurons, and small spherical cells. Retrograde tracing combined with immunocytochemistry showed that calretinin is not present in cells projecting to the hippocampus. Few synapic contacts between calretinin-positive axon terminals and immunopositive cell bodies and dendrites were seen. Most axon terminals of calretinin fibers formed asymmetrical synapses, and immunopositive axons were always unmyelinated. Results obtained in the CLSM indicate that calretinin co-exists in only 18-20% of the GABAergic cell population (mostly small spherical and bipolar cells). Thus, the entorhinal cortex contains two classes of calretinin interneurons: GABA positive and GABA negative. The first class is presumably a classical, GABAergic inhibitory interneuron. The finding of calretinin-immunoreactive axon terminals with asymmetrical synapses suggests that the second

  14. Impact of Continuous Versus Discontinuous Progesterone on Estradiol Regulation of Neuron Viability and Sprouting After Entorhinal Cortex Lesion in Female Rats

    PubMed Central

    Barron, Anna M.; Brown, Meghan A.; Morgan, Todd E.

    2015-01-01

    Because the estrogen-based hormone therapy (HT) in postmenopausal women typically contains a progestogen component, understanding the interactions between estrogens and progestogens is critical for optimizing the potential neural benefits of HT. An important issue in this regard is the use of continuous vs discontinuous hormone treatments. Although sex steroid hormone levels naturally exhibit cyclic fluctuation, many HT formulations include continuous delivery of hormones. Recent findings from our laboratory and others have shown that coadministration of progesterone (P4) can either attenuate or augment beneficial actions of 17β-estradiol (E2) in experimental models depending in part upon the delivery schedule of P4. In this study, we demonstrate that the P4 delivery schedule in combined E2 and P4 treatments alters degenerative and regenerative outcomes of unilateral entorhinal cortex lesion. We assessed how lesion-induced degeneration of layer II neurons in entorhinal cortex layer and deafferentation in dentate gyrus are affected by ovariectomy and treatments with E2 alone or in combination with either continuous or discontinuous P4. Our results demonstrate the combined efficacy of E2 and P4 is dependent on the administration regimen. Importantly, the discontinuous-combined E2+P4 regimen had the greatest neuroprotective efficacy for both end points. These data extend a growing literature that indicates qualitative differences in the neuroprotective effects of E2 as a function of cotreatment with continuous versus discontinuous P4, the understanding of which has important implications for HT in postmenopausal women. PMID:25514084

  15. Training in the step-down inhibitory avoidance task time-dependently increases cAMP-dependent protein kinase activity in the entorhinal cortex.

    PubMed

    Pereira, P; Ardenghi, P; Mello e Souza, T; Medina, J H; Izquierdo, I

    2001-06-01

    The cAMP/cAMP-dependent protein kinase (PKA) signaling pathway has been implicated in synaptic plasticity changes and memory consolidation. Several cortical structures are involved in the consolidation of memory for inhibitory avoidance. The aim of the present work was to observe the effects of training in the inhibitory avoidance task on the levels of PKA activity in the entorhinal, parietal and posterior cingulate cortex (EC, PARIET and PC), and the medial precentral area (Fr2) of the rat, at different post-training times (0, 1.5, 3 and 6h). PKA activity, assayed using [gamma-32P]ATP and kemptide, a selective substrate, increased in the EC 3 h after training, but no changes were observed in PARIET, PC and Fr2. These results suggest that the late phase of memory consolidation of inhibitory avoidance requires a functional PKA signaling pathway in the EC in a way that a 'peak' of PKA activity is observed.

  16. Localization of two major GABA(A) receptor subunits in the dentate gyrus of the rat and cell type-specific up-regulation following entorhinal cortex lesion.

    PubMed

    Simbürger, E; Plaschke, M; Fritschy, J M; Nitsch, R

    2001-01-01

    GABA(A) receptor subunits show a specific regional distribution in the CNS during development and in the adult animal. In the hippocampal formation, individual subsets of GABAergic interneurons are highly immunoreactive for the alpha1-subunit, whereas granule and pyramidal cells show a strong expression of the alpha2-subunit. Using confocal microscopy and digital image analysis, we demonstrate that in the dentate gyrus the alpha1-subunit immunolabeling appears in differently sized clusters. The large clusters, which are confined to dendrites of interneurons, show no alpha2 labeling, whereas the smaller ones coincide with alpha2-subunit-positive clusters. In the molecular layer, the clusters of both alpha-subunits co-localize with the anchoring protein gephyrin. In the granule cell layer and hilus, we found alpha1- and alpha2-subunit-positive clusters which were devoid of gephyrin labeling. Lesions of the medial entorhinal cortex led to the deafferentation of dendrites in the middle molecular layer of the dentate gyrus. This resulted in a significantly increased concentration of alpha2-subunit-positive clusters. We also observed an increase of alpha1-subunit immunolabeling in the deafferented area. We found no change in the co-localization between alpha1 and alpha2, and no significant change in the number of large alpha1-positive clusters along individual dendritic segments of interneurons. In a previous study, we demonstrated that calbindin-immunoreactive dendrites of granule cells revealed a significant increase in gephyrin immunoreactivity following lesion, whereas parvalbumin-positive dendrites showed no such alterations. The predominant localization of small gephyrin clusters in dendrites of granule cells, which was also described in this study, leads to the conclusion that the increase of the alpha2-subunit-positive clusters, demonstrated in the present study, indicates that, following entorhinal cortex lesion, new GABAergic synapses may be formed and that

  17. 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.

  18. Selective activation of parvalbumin- or somatostatin-expressing interneurons triggers epileptic seizurelike activity in mouse medial entorhinal cortex.

    PubMed

    Yekhlef, Latefa; Breschi, Gian Luca; Lagostena, Laura; Russo, Giovanni; Taverna, Stefano

    2015-03-01

    GABAergic interneurons are thought to play a critical role in eliciting interictal spikes (IICs) and triggering ictal discharges in temporal lobe epilepsy, yet the contribution of different interneuronal subtypes to seizure initiation is still largely unknown. Here we took advantage of optogenetic techniques combined with patch-clamp and field recordings to selectively stimulate parvalbumin (PV)- or somatostatin (SOM)-positive interneurons expressing channelrhodopsin-2 (CHR-2) in layers II-III of adult mouse medial entorhinal cortical slices during extracellular perfusion with the proconvulsive compound 4-aminopyridine (4-AP, 100-200 μM). In control conditions, blue laser photostimulation selectively activated action potential firing in either PV or SOM interneurons and, in both cases, caused a robust GABAA-receptor-mediated inhibition in pyramidal cells (PCs). During perfusion with 4-AP, brief photostimuli (300 ms) activating either PV or SOM interneurons induced patterns of epileptiform activity that closely replicated spontaneously occurring IICs and tonic-clonic ictal discharges. Laser-induced synchronous firing in both interneuronal types elicited large compound GABAergic inhibitory postsynaptic currents (IPSCs) correlating with IICs and preictal spikes. In addition, spontaneous and laser-induced epileptic events were similarly initiated in concurrence with a large increase in extracellular potassium concentration. Finally, interneuron activation was unable to stop or significantly shorten the progression of seizurelike episodes. These results suggest that entorhinal PV and SOM interneurons are nearly equally effective in triggering interictal and ictal discharges that closely resemble human temporal lobe epileptic activity.

  19. Aspiration.

    PubMed

    Hancocks, S

    2003-03-22

    Aspiration lands in the dictionary between aspidistra and aspirin - a Victorian parlour plant and an anti-inflammatory with new-found cardiac and DVT prevention qualities. What do we make of that as a sign of the times?

  20. Kainate receptors in the rat hippocampus: A distribution and time course of changes in response to unilateral lesions of the entorhinal cortex

    SciTech Connect

    Ulas, J.; Monaghan, D.T.; Cotman, C.W. )

    1990-07-01

    The response of kainate receptors to deafferentation and subsequent reinnervation following unilateral entorhinal cortex lesions was studied in the rat hippocampus using quantitative in vitro autoradiography. The binding levels of (3H)kainic acid (KA) and changes in the distribution of KA sites were investigated in the dentate gyrus molecular layer (ML) and in various terminal zones in the CA1 field at 1, 3, 7, 14, 21, 30, and 60 d postlesion. The data from both the ipsilateral and contralateral hippocampus were compared with those from unoperated controls. The first changes in KA receptor distribution were observed 21 d postlesion when the dense band of KA receptors occupying the inner one-third of the ML expanded into the denervated outer two-thirds of the ipsilateral ML. The spreading of the KA receptor field into previously unoccupied zones continued 30 and 60 d postlesion. At these time points, the zone enriched in (3H)KA binding sites became significantly (on average 50%) wider than in unoperated controls. No changes were observed in either the distribution or binding levels in other hippocampal areas or in the contralateral hippocampus at any studied time point. Saturation analysis of binding in the ipsilateral ML 60 d postlesion revealed changes in the maximum number of receptor sites (Bmax) without changes in KA receptor affinity (Kd). The data suggest that the elevation of the (3H)KA binding in the outer two-thirds of the ML reflects an increase in the number of both low and high affinity receptor binding sites. The pattern of KA receptor redistribution was similar to the well-characterized pattern of sprouting of commissural/associational systems from the inner one-third into the outer two-thirds of the ML after entorhinal lesions.

  1. Model for Probing Membrane-Cortex Adhesion by Micropipette Aspiration and Fluctuation Spectroscopy

    PubMed Central

    Alert, Ricard; Casademunt, Jaume; Brugués, Jan; Sens, Pierre

    2015-01-01

    We propose a model for membrane-cortex adhesion that couples membrane deformations, hydrodynamics, and kinetics of membrane-cortex ligands. In its simplest form, the model gives explicit predictions for the critical pressure for membrane detachment and for the value of adhesion energy. We show that these quantities exhibit a significant dependence on the active acto-myosin stresses. The model provides a simple framework to access quantitative information on cortical activity by means of micropipette experiments. We also extend the model to incorporate fluctuations and show that detailed information on the stability of membrane-cortex coupling can be obtained by a combination of micropipette aspiration and fluctuation spectroscopy measurements. PMID:25902428

  2. Optogenetic activation of VGLUT2-expressing excitatory neurons blocks epileptic seizure-like activity in the mouse entorhinal cortex

    PubMed Central

    Yekhlef, Latefa; Breschi, Gian Luca; Taverna, Stefano

    2017-01-01

    We investigated whether an anti-epileptic effect is obtained by selectively activating excitatory neurons expressing ChR2 under the promoter for the synaptic vesicular glutamate transporter 2 (VGLUT2). VGLUT2-expressing cells were optically stimulated while local field potential and whole-cell patch-clamp recordings were performed in mouse entorhinal cortical slices perfused with the proconvulsive compound 4-aminopyridine (4-AP). In control conditions, blue light flashes directly depolarized the majority of putative glutamatergic cells, which in turn synaptically excited GABAergic interneurons. During bath perfusion with 4-AP, photostimuli triggered a fast EPSP-IPSP sequence which was often followed by tonic-clonic seizure-like activity closely resembling spontaneous ictal discharges. The GABAA-receptor antagonist gabazine blocked the progression of both light-induced and spontaneous seizures. Surprisingly, prolonged photostimuli delivered during ongoing seizures caused a robust interruption of synchronous discharges. Such break was correlated with a membrane potential depolarization block in principal cells, while putative GABAergic interneurons changed their firing activity from a burst-like to an irregular single-spike pattern. These data suggest that photostimulation of glutamatergic neurons triggers seizure-like activity only in the presence of an intact GABAergic transmission and that selectively activating the same glutamatergic cells robustly interrupts ongoing seizures by inducing a strong depolarization block, resulting in the disruption of paroxysmal burst-like firing. PMID:28230208

  3. Neonatal functional blockade of the entorhinal cortex results in disruption of accumbal dopaminergic responses observed in latent inhibition paradigm in adult rats.

    PubMed

    Peterschmitt, Y; Meyer, F; Louilot, A

    2007-04-01

    Latent inhibition (LI) has been found to be disrupted in non-treated patients with schizophrenia. Dopaminergic (DAergic) dysfunctioning is generally acknowledged to occur in schizophrenia. Various abnormalities in the entorhinal cortex (ENT) have been described in patients with schizophrenia. Numerous data also suggest that schizophrenia has a neurodevelopmental origin. The present study was designed to test the hypothesis that reversible inactivation of the ENT during neonatal development results in disrupted DA responses characteristic of LI in adult rats. Tetrodotoxin (TTX) was microinjected locally in the left ENT at postnatal day 8 (PND8). DA variations were recorded in the dorsomedial shell and core parts of the nucleus accumbens (Nacc) using in vivo voltammetry in freely-moving grown-up rats in a LI paradigm. In the first session the animals were pre-exposed (PE) to the conditional stimulus (banana odour) alone. In the second they were aversively conditioned to banana odour. In the third (test) session the following results were obtained in PE animals subjected to temporary inactivation of the ENT at PND8: (1) aversive behaviour was observed in TTX-PE conditioned animals; (2) DA variations in the dorsomedial shell and core parts of the Nacc were similar in TTX-PE and non-pre-exposed conditioned rats. These findings strongly suggest that neonatal disconnection of the ENT disrupts LI in adult animals. They may further our understanding of the pathophysiology of schizophrenia.

  4. 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.

  5. 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.

  6. Dynamics of rat entorhinal cortex layer II and III cells: characteristics of membrane potential resonance at rest predict oscillation properties near threshold

    PubMed Central

    Erchova, I; Kreck, G; Heinemann, U; Herz, A V M

    2004-01-01

    Neurones generate intrinsic subthreshold membrane potential oscillations (MPOs) under various physiological and behavioural conditions. These oscillations influence neural responses and coding properties on many levels. On the single-cell level, MPOs modulate the temporal precision of action potentials; they also have a pronounced impact on large-scale cortical activity. Recent studies have described a close association between the MPOs of a given neurone and its electrical resonance properties. Using intracellular sharp microelectrode recordings we examine both dynamical characteristics in layers II and III of the entorhinal cortex (EC). Our data from EC layer II stellate cells show strong membrane potential resonances and oscillations, both in the range of 5–15 Hz. At the resonance maximum, the membrane impedance can be more than twice as large as the input resistance. In EC layer III cells, MPOs could not be elicited, and frequency-resolved impedances decay monotonically with increasing frequency or has only a small peak followed by a subsequent decay. To quantify and compare the resonance and oscillation properties, we use a simple mathematical model that includes stochastic components to capture channel noise. Based on this model we demonstrate that electrical resonance is closely related though not equivalent to the occurrence of sag-potentials and MPOs. MPO frequencies can be predicted from the membrane impedance curve for stellate cells. The model also explains the broad-band nature of the observed MPOs. This underscores the importance of intrinsic noise sources for subthreshold phenomena and rules out a deterministic description of MPOs. In addition, our results show that the two identified cell classes in the superficial EC layers, which are known to target different areas in the hippocampus, also have different preferred frequency ranges and dynamic characteristics. Intrinsic cell properties may thus play a major role for the frequency

  7. [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

  8. Gonadal status-dependent effects of in vivo β-estradiol administration to female rats on in vitro epileptiform activity induced by low [Mg2+]₀ in combined hippocampus-entorhinal cortex slices.

    PubMed

    Velíšková, Jana; Velíšek, Libor

    2013-12-01

    There are controversial data regarding estrogen effects on neuronal excitability. We investigated whether β-estradiol (EB) administration to ovariectomized (OVX) or gonadally intact female rats alters epileptiform activity within the dentate gyrus network induced in vitro by removing [Mg2+]o in combined hippocampus-entorhinal cortex slices. In vivo EB administration significantly influenced the epileptiform activity in gonadal status-dependent manner. The onset of epileptiform discharges was modestly delayed in slices from OVX rats replaced with physiologically relevant doses of EB but the number of discharges was not affected. In contrast, EB administration to gonadally intact rats had robust effects such that: EB delayed the onset of discharges but significantly increased their number within the dentate gyrus network. Our data suggest that EB in physiologically relevant concentrations does not seem to negatively affect hippocampal neuronal excitability, nevertheless supraphysiological EB levels may enhance seizure severity.

  9. Spontaneous rhythmic field potentials of isolated mouse hippocampal-subicular-entorhinal cortices in vitro.

    PubMed

    Wu, C P; Huang, H L; Asl, M Nassiri; He, J W; Gillis, J; Skinner, F K; Zhang, L

    2006-10-15

    The rodent hippocampal circuit is capable of exhibiting in vitro spontaneous rhythmic field potentials (SRFPs) of 1-4 Hz that originate from the CA3 area and spread to the CA1 area. These SRFPs are largely correlated with GABA-A IPSPs in pyramidal neurons and repetitive discharges in inhibitory interneurons. As such, their generation is thought to result from cooperative network activities involving both pyramidal neurons and GABAergic interneurons. Considering that the hippocampus, subiculum and entorhinal cortex function as an integrated system crucial for memory and cognition, it is of interest to know whether similar SRFPs occur in hippocampal output structures (that is, the subiculum and entorhinal cortex), and if so, to understand the cellular basis of these subicular and entorhinal SRFPs as well as their temporal relation to hippocampal SRFPs. We explored these issues in the present study using thick hippocampal-subicular-entorhinal cortical slices prepared from adult mice. SRFPs were found to spread from the CA1 area to the subicular and entorhinal cortical areas. Subicular and entorhinal cortical SRFPs were correlated with mixed IPSPs/EPSPs in local pyramidal neurons, and their generation was dependent upon the activities of GABA-A and AMPA glutamate receptors. In addition, the isolated subicular circuit could elicit SRFPs independent of CA3 inputs. We hypothesize that the SRFPs represent a basal oscillatory activity of the hippocampal-subicular-entorhinal cortices and that the subiculum functions as both a relay and an amplifier, spreading the SRFPs from the hippocampus to the entorhinal cortex.

  10. 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…

  11. Protective effect of APOE epsilon 2 on intrinsic functional connectivity of the entorhinal cortex is associated with better episodic memory in elderly individuals with risk factors for Alzheimer's disease

    PubMed Central

    Chen, Jiu; Shu, Hao; Wang, Zan; Liu, Duan; Shi, Yongmei; Xu, Lin; Zhang, Zhijun

    2016-01-01

    The apolipoprotein E (APOE) ε4 allele associates with accelerating the conversion from amnestic mild cognitive impairment (aMCI) to Alzheimer's disease (AD), whereas the protectiveAPOEε2 allele appears to be against the disease. Moreover, entorhinal cortex (ERC) is one of the earliest brain regions of AD pathology that disrupts the formation of episodic memory. To investigate the effects of APOE ε2 and ε4alleles on functional connectivity (FC) of ERC and cognition in aMCI. Methods The FC analyses of ERC were performed in 83 aMCI (9 ε2-carrier, 44 ε3ε3, and 30 ε4-carrier) and 88 healthy controls (HC, 15 ε2-carrier, 40 ε3ε3, and 33 ε4-carrier). Multiple linear regression model was performed between the altered ERC connectivities and cognition. In the ERC network, aMCI with ε4-carriers showed decreased FC in the bilateral middle temporal gyrus (MTG), right precuneus, and right precentral gyrus (PreCG), while ε2-carriers showed increased FC in these regions (except the right PreCG) compared to HC. The altered FC between ERC and right MTG correlated with episodic memory performance in aMCI carried ε2 and ε4 alleles. These results suggest that the effects ofAPOEon the ERC network are closely linked to the role of this gene on AD risk, which aMCI with ε4-carriers can accelerate the pathological progression of network-based mechanisms while ε2-carriers may play a protective role in contributing to a compensatory mechanism. It further suggests that APOE can appear to directly affect the ERC-MTG neural pathway associated with the impairment of episodic memory in aMCI. PMID:27542235

  12. Temporal frequency of subthreshold oscillations scales with entorhinal grid cell field spacing.

    PubMed

    Giocomo, Lisa M; Zilli, Eric A; Fransén, Erik; Hasselmo, Michael E

    2007-03-23

    Grid cells in layer II of rat entorhinal cortex fire to spatial locations in a repeating hexagonal grid, with smaller spacing between grid fields for neurons in more dorsal anatomical locations. Data from in vitro whole-cell patch recordings showed differences in frequency of subthreshold membrane potential oscillations in entorhinal neurons that correspond to different positions along the dorsal-to-ventral axis, supporting a model of physiological mechanisms for grid cell responses.

  13. The entorhinal grid map is discretized.

    PubMed

    Stensola, Hanne; Stensola, Tor; Solstad, Trygve; Frøland, Kristian; Moser, May-Britt; Moser, Edvard I

    2012-12-06

    The medial entorhinal cortex (MEC) is part of the brain's circuit for dynamic representation of self-location. The metric of this representation is provided by grid cells, cells with spatial firing fields that tile environments in a periodic hexagonal pattern. Limited anatomical sampling has obscured whether the grid system operates as a unified system or a conglomerate of independent modules. Here we show with recordings from up to 186 grid cells in individual rats that grid cells cluster into a small number of layer-spanning anatomically overlapping modules with distinct scale, orientation, asymmetry and theta-frequency modulation. These modules can respond independently to changes in the geometry of the environment. The discrete topography of the grid-map, and the apparent autonomy of the modules, differ from the graded topography of maps for continuous variables in several sensory systems, raising the possibility that the modularity of the grid map is a product of local self-organizing network dynamics.

  14. Entorhinal cortical innervation of parvalbumin-containing neurons (Basket and Chandelier cells) in the rat Ammon's horn.

    PubMed

    Kiss, J; Buzsaki, G; Morrow, J S; Glantz, S B; Leranth, C

    1996-01-01

    Physiological data suggest that in the CA1-CA3 hippocampal areas of rats, entorhinal cortical efferents directly influence the activity of interneurons, in addition to pyramidal cells. To verify this hypothesis, the following experiments were performed: 1) light microscopic double-immunostaining for parvalbumin and the anterograde tracer Phaseolus vulgaris-leucoagglutinin injected into the entorhinal cortex; 2) light and electron microscopic analysis of cleaved spectrin-immunostained (i.e., degenerating axons and boutons) hippocampal sections following entorhinal cortex lesion; and 3) an electron microscopic study of parvalbumin-immunostained hippocampal sections after entorhinal cortex lesion. The results demonstrate that in the stratum lacunosum-moleculare of the CA1 and CA3 regions, entorhinal cortical axons form asymmetric synaptic contacts on parvalbumin-containing dendritic shafts. In the stratum lacunosum-moleculare, parvalbumin-immunoreactive dendrites represent processes of GABAergic, inhibitory basket and chandelier cells; these interneurons innervate the perisomatic area and axon initial segments of pyramidal cells, respectively. A feed-forward activation of these neurons by the entorhinal input may explain the strong, short-latency inhibition of pyramidal cells.

  15. 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 ...

  16. Entorhinal volume, aerobic fitness, and recognition memory in healthy young adults: a voxel-based morphometry study1

    PubMed Central

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

    2015-01-01

    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 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. PMID:26631814

  17. 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.

  18. 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

  19. Robust path integration in the entorhinal grid cell system with hippocampal feed-back.

    PubMed

    Samu, Dávid; Eros, Péter; Ujfalussy, Balázs; Kiss, Tamás

    2009-07-01

    Animals are able to update their knowledge about their current position solely by integrating the speed and the direction of their movement, which is known as path integration. Recent discoveries suggest that grid cells in the medial entorhinal cortex might perform some of the essential underlying computations of path integration. However, a major concern over path integration is that as the measurement of speed and direction is inaccurate, the representation of the position will become increasingly unreliable. In this paper, we study how allothetic inputs can be used to continually correct the accumulating error in the path integrator system. We set up the model of a mobile agent equipped with the entorhinal representation of idiothetic (grid cell) and allothetic (visual cells) information and simulated its place learning in a virtual environment. Due to competitive learning, a robust hippocampal place code emerges rapidly in the model. At the same time, the hippocampo-entorhinal feed-back connections are modified via Hebbian learning in order to allow hippocampal place cells to influence the attractor dynamics in the entorhinal cortex. We show that the continuous feed-back from the integrated hippocampal place representation is able to stabilize the grid cell code.

  20. Head direction is coded more strongly than movement direction in a population of entorhinal neurons

    PubMed Central

    Raudies, Florian; Brandon, Mark P.; Chapman, G. William; Hasselmo, Michael E.

    2014-01-01

    The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/sec and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. PMID:25451111

  1. Head direction is coded more strongly than movement direction in a population of entorhinal neurons.

    PubMed

    Raudies, Florian; Brandon, Mark P; Chapman, G William; Hasselmo, Michael E

    2015-09-24

    The spatial firing pattern of entorhinal grid cells may be important for navigation. Many different computational models of grid cell firing use path integration based on movement direction and the associated movement speed to drive grid cells. However, the response of neurons to movement direction has rarely been tested, in contrast to multiple studies showing responses of neurons to head direction. Here, we analyzed the difference between head direction and movement direction during rat movement and analyzed cells recorded from entorhinal cortex for their tuning to movement direction. During foraging behavior, movement direction differs significantly from head direction. The analysis of neuron responses shows that only 5 out of 758 medial entorhinal cells show significant coding for both movement direction and head direction when evaluating periods of rat behavior with speeds above 10 cm/s and ±30° angular difference between movement and head direction. None of the cells coded movement direction alone. In contrast, 21 cells in this population coded only head direction during behavioral epochs with these constraints, indicating much stronger coding of head direction in this population. This suggests that the movement direction signal required by most grid cell models may arise from other brain structures than the medial entorhinal cortex. This article is part of a Special Issue entitled SI: Brain and Memory.

  2. 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

  3. Amount of lifetime video gaming is positively associated with entorhinal, hippocampal and occipital volume.

    PubMed

    Kühn, S; Gallinat, J

    2014-07-01

    Playing video games is a popular leisure activity among children and adults, and may therefore potentially influence brain structure. We have previously shown a positive association between probability of gray matter (GM) volume in the ventral striatum and frequent video gaming in adolescence. Here we set out to investigate structural correlates of video gaming in adulthood, as the effects observed in adolescents may reflect only a fraction of the potential neural long-term effects seen in adults. On magnetic resonance imaging (MRI) scans of 62 male adults, we computed voxel-based morphometry to explore the correlation of GM with the lifetime amount of video gaming (termed joystick years). We found a significant positive association between GM in bilateral parahippocamal region (entorhinal cortex) and left occipital cortex/inferior parietal lobe and joystick years (P<0.001, corrected for multiple comparisons). An exploratory analysis showed that the entorhinal GM volume can be predicted by the video game genres played, such as logic/puzzle games and platform games contributing positively, and action-based role-playing games contributing negatively. Furthermore, joystick years were positively correlated with hippocampus volume. The association of lifetime amount of video game playing with bilateral entorhinal cortex, hippocampal and occipital GM volume could reflect adaptive neural plasticity related to navigation and visual attention.

  4. Lateral entorhinal modulation of piriform cortical activity and fine odor discrimination.

    PubMed

    Chapuis, Julie; Cohen, Yaniv; He, Xiaobin; Zhang, Zhijan; Jin, Sen; Xu, Fuqiang; Wilson, Donald A

    2013-08-14

    The lateral entorhinal cortex (LEC) receives direct input from olfactory bulb mitral cells and piriform cortical pyramidal cells and is the gateway for olfactory input to the hippocampus. However, the LEC also projects back to the piriform cortex and olfactory bulb. Activity in the LEC is shaped by input from the perirhinal cortices, hippocampus, and amygdala, and thus could provide a rich contextual modulation of cortical odor processing. The present study further explored LEC feedback to anterior piriform cortex by examining how LEC top-down input modulates anterior piriform cortex odor evoked activity in rats. Retrograde viral tracing confirmed rich LEC projections to both the olfactory bulb and piriform cortices. In anesthetized rats, reversible lesions of the ipsilateral LEC increased anterior piriform cortical single-unit spontaneous activity. In awake animals performing an odor discrimination task, unilateral LEC reversible lesions enhanced ipsilateral piriform cortical local field potential oscillations during odor sampling, with minimal impact on contralateral activity. Bilateral LEC reversible lesions impaired discrimination performance on a well learned, difficult odor discrimination task, but had no impact on a well learned simple odor discrimination task. The simple discrimination task was impaired by bilateral reversible lesions of the anterior piriform cortex. Given the known function of LEC in working memory and multisensory integration, these results suggest it may serve as a powerful top-down modulator of olfactory cortical function and odor perception. Furthermore, the results provide potential insight into how neuropathology in the entorhinal cortex could contribute to early olfactory deficits seen in Alzheimer's disease.

  5. "Aspiration disease".

    PubMed

    Pradhan, D J; Ikins, P M

    1976-03-01

    Aspiration disease, a term used to define both an acute and chronic form of a disease entity, is described. Etiological factors, pathophysiology and therapy are discussed with emphasis on aspiration of gastric juice. A brief mention of a small clinical experience is included.

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

    PubMed

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

    2015-09-23

    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.

  7. How does the modular organization of entorhinal grid cells develop?

    PubMed Central

    Pilly, Praveen K.; Grossberg, Stephen

    2014-01-01

    The entorhinal-hippocampal system plays a crucial role in spatial cognition and navigation. Since the discovery of grid cells in layer II of medial entorhinal cortex (MEC), several types of models have been proposed to explain their development and operation; namely, continuous attractor network models, oscillatory interference models, and self-organizing map (SOM) models. Recent experiments revealing the in vivo intracellular signatures of grid cells (Domnisoru et al., 2013; Schmidt-Heiber and Hausser, 2013), the primarily inhibitory recurrent connectivity of grid cells (Couey et al., 2013; Pastoll et al., 2013), and the topographic organization of grid cells within anatomically overlapping modules of multiple spatial scales along the dorsoventral axis of MEC (Stensola et al., 2012) provide strong constraints and challenges to existing grid cell models. This article provides a computational explanation for how MEC cells can emerge through learning with grid cell properties in modular structures. Within this SOM model, grid cells with different rates of temporal integration learn modular properties with different spatial scales. Model grid cells learn in response to inputs from multiple scales of directionally-selective stripe cells (Krupic et al., 2012; Mhatre et al., 2012) that perform path integration of the linear velocities that are experienced during navigation. Slower rates of grid cell temporal integration support learned associations with stripe cells of larger scales. The explanatory and predictive capabilities of the three types of grid cell models are comparatively analyzed in light of recent data to illustrate how the SOM model overcomes problems that other types of models have not yet handled. PMID:24917799

  8. How does the modular organization of entorhinal grid cells develop?

    PubMed

    Pilly, Praveen K; Grossberg, Stephen

    2014-01-01

    The entorhinal-hippocampal system plays a crucial role in spatial cognition and navigation. Since the discovery of grid cells in layer II of medial entorhinal cortex (MEC), several types of models have been proposed to explain their development and operation; namely, continuous attractor network models, oscillatory interference models, and self-organizing map (SOM) models. Recent experiments revealing the in vivo intracellular signatures of grid cells (Domnisoru et al., 2013; Schmidt-Heiber and Hausser, 2013), the primarily inhibitory recurrent connectivity of grid cells (Couey et al., 2013; Pastoll et al., 2013), and the topographic organization of grid cells within anatomically overlapping modules of multiple spatial scales along the dorsoventral axis of MEC (Stensola et al., 2012) provide strong constraints and challenges to existing grid cell models. This article provides a computational explanation for how MEC cells can emerge through learning with grid cell properties in modular structures. Within this SOM model, grid cells with different rates of temporal integration learn modular properties with different spatial scales. Model grid cells learn in response to inputs from multiple scales of directionally-selective stripe cells (Krupic et al., 2012; Mhatre et al., 2012) that perform path integration of the linear velocities that are experienced during navigation. Slower rates of grid cell temporal integration support learned associations with stripe cells of larger scales. The explanatory and predictive capabilities of the three types of grid cell models are comparatively analyzed in light of recent data to illustrate how the SOM model overcomes problems that other types of models have not yet handled.

  9. Hyperexcitability in combined entorhinal/hippocampal slices of adult rat after exposure to brain-derived neurotrophic factor.

    PubMed

    Scharfman, H E

    1997-08-01

    Effects of brain-derived neurotrophic factor (BDNF) in area CA3, the dentate gyrus, and medial entorhinal cortex were examined electrophysiologically by bath application of BDNF in slices containing the hippocampus and entorhinal cortex. Bath application of 25-100 ng/ml BDNF for 30-90 min increased responses to single afferent stimuli in selective pathways in the majority of slices. In area CA3, responses to mossy fiber stimulation increased in 73% of slices and entorhinal cortex responses to white matter stimulation increased in 64% of slices. After exposure to BDNF, these areas also demonstrated evidence of hyperexcitability, because responses to repetitive stimulation (1-Hz paired pulses for several s) produced multiple population spikes in response to mossy fiber stimulation in CA3 or multiple field potentials in response to white matter stimulation in the entorhinal cortex. Repetitive field potentials persisted after repetitive stimulation ended and usually were followed by spreading depression. Enhancement of responses to single stimuli and hyperexcitability were never evoked in untreated slices or after bath application of boiled BDNF or cytochrome C. The tyrosine kinase antagonist K252a (2 microM) blocked the effects of BDNF. In area CA3, both the potentiation of responses to single stimuli and hyperexcitability showed afferent specificity, because responses to mossy fiber stimulation were affected but responses to fimbria or Schaffer collateral stimulation were not. In addition, regional specificity was demonstrated in that the dentate gyrus was much less affected. The effects of BDNF in area CA3 were similar to those produced by bath application of low doses of kainic acid, which is thought to modulate glutamate release from mossy fiber terminals by a presynaptic action. These results suggest that BDNF has acute effects on excitability in different areas of the hippocampal-entorhinal circuit. These effects appear to be greatest in areas that are highly

  10. Crossed pathways from the entorhinal area to the fascia dentata. II. Provokable in rats.

    PubMed

    Zimmer, J; Hjorth-Simonsen, A

    1975-05-01

    In the rat thhe perforant pathways from the entorhinal area normally innervate the fascia dentata only ipsilaterally. However, unilateral ablation of the entorhinal area (deentorhination) induces the formation of an anomalous crossed projection from the intact contralateral entorhinal area to the septal portion of the deafferented fascia dentata. After deentorhination of rats aged 1-30 days the organization of this projection was analyzed (a) by producing secondary lesions in the intact entorhinal area of perforant paths and observing the results anterograde degeneration with Fink-Heimer silver impregnation techniques, and (b) by staining with Timm's sulfide silver method whichmakes the terminal fields of afferent systems stand out in different tones of colors. Both methods showed the crossed entorhino-dentate projection to consist of two separable components. They were named the crossed medial perforant path and the crossed lateral perforant path, corresponding to their similarity in origin, dendritic localization of termination and Timm stainability to the ordinary, uncrossed medial and the lateral perforant pathways (MPP and LPP) which arise in the medial and lateral parts of the entorhinal cortex, respectively. Similarly induced crossed projections were demonstrated to the subcallosal continuation of fascia dentata, the fasciola cinerea. The heaviest terminal field of the crossed entorhino-dentate projection which was found in the most rostral and medial parts of the deafferented fascia dentata correlated with a lack of expected aberrant extension into theMPP and LPP terminal zones of commissural and ipsilateral hippocampodentate fibers. In Fink-Heimer preparations there was little variation in the distribution of the aberrant crossed sustems over the range of ages studied although the chronic operations performed earliest postnatally (5 days) tended to produce the heaviest representation. This latter observation appeared consistent with changes in the Timm

  11. 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.

  12. A circuit-level model of hippocampal place field dynamics modulated by entorhinal grid and suppression-generating cells.

    PubMed

    Jayet Bray, Laurence C; Quoy, Mathias; Harris, Frederick C; Goodman, Philip H

    2010-01-01

    Hippocampal "place cells" and the precession of their extracellularly recorded spiking during traversal of a "place field" are well-established phenomena. More recent experiments describe associated entorhinal "grid cell" firing, but to date only conceptual models have been offered to explain the potential interactions among entorhinal cortex (EC) and hippocampus. To better understand not only spatial navigation, but mechanisms of episodic and semantic memory consolidation and reconsolidation, more detailed physiological models are needed to guide confirmatory experiments. Here, we report the results of a putative entorhinal-hippocampal circuit level model that incorporates recurrent asynchronous-irregular non-linear (RAIN) dynamics, in the context of recent in vivo findings showing specific intracellular-extracellular precession disparities and place field destabilization by entorhinal lesioning. In particular, during computer-simulated rodent maze navigation, our model demonstrate asymmetric ramp-like depolarization, increased theta power, and frequency (that can explain the phase precession disparity), and a role for STDP and K(AHP) channels. Additionally, we propose distinct roles for two entorhinal cell populations projecting to hippocampus. Grid cell populations transiently trigger place field activity, while tonic "suppression-generating cell" populations minimize aberrant place cell activation, and limit the number of active place cells during traversal of a given field. Applied to place-cell RAIN networks, this tonic suppression explains an otherwise seemingly discordant association with overall increased firing. The findings of this circuit level model suggest in vivo and in vitro experiments that could refute or support the proposed mechanisms of place cell dynamics and modulating influences of EC.

  13. Knock-out of HCN1 subunit flattens dorsal-ventral frequency gradient of medial entorhinal neurons in adult mice.

    PubMed

    Giocomo, Lisa M; Hasselmo, Michael E

    2009-06-10

    Layer II stellate cells at different locations along the dorsal to ventral axis of medial entorhinal cortex show differences in the frequency of intrinsic membrane potential oscillations and resonance (Giocomo et al., 2007). The frequency differences scale with differences in the size and spacing of grid-cell firing fields recorded in layer II of the medial entorhinal cortex in behaving animals. To determine the mechanism for this difference in intrinsic frequency, we analyzed oscillatory properties in adult control mice and adult mice with a global deletion of the HCN1 channel. Data from whole-cell patch recordings show that the oscillation frequency gradient along the dorsal-ventral axis previously shown in juvenile rats also appears in control adult mice, indicating that the dorsal-ventral gradient generalizes across age and species. Knock-out of the HCN1 channel flattens the dorsal-ventral gradient of the membrane potential oscillation frequency, the resonant frequency, the time constant of the "sag" potential and the amplitude of the sag potential. This supports a role of the HCN1 subunit in the mechanism of the frequency gradient in these neurons. These findings have important implications for models of grid cells and generate predictions for future in vivo work on entorhinal grid cells.

  14. A Kalman filtering approach to the representation of kinematic quantities by the hippocampal-entorhinal complex.

    PubMed

    Osborn, Graham Wordsworth

    2010-12-01

    Several regions of the brain which represent kinematic quantities are grouped under a single state-estimator framework. A theoretic effort is made to predict the activity of each cell population as a function of time using a simple state estimator (the Kalman filter). Three brain regions are considered in detail: the parietal cortex (reaching cells), the hippocampus (place cells and head-direction cells), and the entorhinal cortex (grid cells). For the reaching cell and place cell examples, we compute the perceived probability distributions of objects in the environment as a function of the observations. For the grid cell example, we show that the elastic behavior of the grids observed in experiments arises naturally from the Kalman filter. To our knowledge, the application of a tensor Kalman filter to grid cells is completely novel.

  15. OLM interneurons differentially modulate CA3 and entorhinal inputs to hippocampal CA1 neurons.

    PubMed

    Leão, Richardson N; Mikulovic, Sanja; Leão, Katarina E; Munguba, Hermany; Gezelius, Henrik; Enjin, Anders; Patra, Kalicharan; Eriksson, Anders; Loew, Leslie M; Tort, Adriano B L; Kullander, Klas

    2012-11-01

    The vast diversity of GABAergic interneurons is believed to endow hippocampal microcircuits with the required flexibility for memory encoding and retrieval. However, dissection of the functional roles of defined interneuron types has been hampered by the lack of cell-specific tools. We identified a precise molecular marker for a population of hippocampal GABAergic interneurons known as oriens lacunosum-moleculare (OLM) cells. By combining transgenic mice and optogenetic tools, we found that OLM cells are important for gating the information flow in CA1, facilitating the transmission of intrahippocampal information (from CA3) while reducing the influence of extrahippocampal inputs (from the entorhinal cortex). Furthermore, we found that OLM cells were interconnected by gap junctions, received direct cholinergic inputs from subcortical afferents and accounted for the effect of nicotine on synaptic plasticity of the Schaffer collateral pathway. Our results suggest that acetylcholine acting through OLM cells can control the mnemonic processes executed by the hippocampus.

  16. 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

  17. OLM interneurons differentially modulate CA3 and entorhinal inputs to hippocampal CA1 neurons

    PubMed Central

    Leão, Richardson N; Mikulovic, Sanja; Leão, Katarina E; Munguba, Hermany; Gezelius, Henrik; Enjin, Anders; Patra, Kalicharan; Eriksson, Anders; Loew, Leslie M.; Tort, Adriano BL; Kullander, Klas

    2012-01-01

    The vast diversity of GABAergic interneurons is believed to endow hippocampal microcircuits with the required flexibility for memory encoding and retrieval. However, dissection of the functional roles of defined interneuron types have been hampered by the lack of cell specific tools. Here we report a precise molecular marker for a population of hippocampal GABAergic interneurons known as oriens lacunosum-moleculare (OLM) cells. By combining novel transgenic mice and optogenetic tools, we demonstrate that OLM cells have a key role in gating the information flow in CA1, facilitating the transmission of intrahippocampal information (from CA3) while reducing the influence of extrahippocampal inputs (from the entorhinal cortex). We further demonstrate that OLM cells are interconnected by gap junctions, receive direct cholinergic inputs from subcortical afferents, and account for the effect of nicotine on synaptic plasticity of the Schaffer collateral pathway. Our results suggest that acetylcholine acting through OLM cells can control the mnemonic processes executed by the hippocampus. PMID:23042082

  18. Channel noise is essential for perithreshold oscillations in entorhinal stellate neurons.

    PubMed

    Dorval, Alan D; White, John A

    2005-10-26

    Previous experimental and computational work (for review, see White et al., 2000) has suggested that channel noise, generated by the stochastic flicker of voltage-gated ion channels, can be a major contributor to electrical membrane noise in neurons. In spiny stellate neurons of the entorhinal cortex, we remove the primary source of channel noise by pharmacologically blocking the native persistent Na+ conductance. Via the dynamic-clamp technique (Robinson and Kawai, 1993; Sharp et al., 1993), we then introduce virtual persistent Na+ channels into the membranes of the stellate neurons. By altering the mathematical properties of these virtual "knock-ins," we demonstrate that stochastic flicker of persistent Na+ channels is necessary for the existence of slow perithreshold oscillations that characterize stellate neurons. Channel noise also alters the ability of stellate neurons to phase lock to weak sinusoidal stimuli. These results provide the first direct demonstration that physiological levels of channel noise can produce qualitative changes in the integrative properties of neurons.

  19. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Joint Aspiration (Arthrocentesis) KidsHealth > For Parents > Joint Aspiration (Arthrocentesis) Print A A A What's in ... español Aspiración articular (artrocentesis) What It Is A joint aspiration (arthrocentesis) is a test that involves withdrawing ( ...

  20. Transsynaptic progression of amyloid-β-induced neuronal dysfunction within the entorhinal-hippocampal network

    PubMed Central

    Harris, Julie A.; Devidze, Nino; Verret, Laure; Ho, Kaitlyn; Halabisky, Brian; Thwin, Myo T.; Kim, Daniel; Hamto, Patricia; Lo, Iris; Yu, Gui-Qiu; Palop, Jorge J.; Masliah, Eliezer; Mucke, Lennart

    2011-01-01

    SUMMARY The entorhinal cortex (EC) is one of the earliest affected and most vulnerable brain regions in Alzheimer’s disease (AD), which is associated with amyloid-β (Aβ) accumulation in many brain areas. We show selective overexpression of mutant amyloid precursor protein (APP) predominantly in layer II/III neurons of the EC causes cognitive and behavioral abnormalities characteristic of mouse models with widespread neuronal APP overexpression, including hyperactivity, disinhibition, and spatial learning and memory deficits. Overexpression of APP/Aβ in the EC elicited abnormalities in synaptic functions and activity-related molecules in the dentate gyrus and CA1, as well as epileptiform activity in parietal cortex. Soluble Aβ was observed in the dentate gyrus and Aβ deposits in the hippocampus were localized to perforant pathway terminal fields. Thus, APP/Aβ expression in EC neurons can cause transsynaptic deficits, which could initiate the cortical-hippocampal network dysfunction observed in mouse models and human patients with AD. PMID:21040845

  1. Acute Intraoperative Pulmonary Aspiration.

    PubMed

    Nason, Katie S

    2015-08-01

    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 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.

  2. Gateways of ventral and dorsal streams in mouse visual cortex

    PubMed Central

    Wang, Quanxin; Gao, Enquan; Burkhalter, Andreas

    2011-01-01

    It is widely held that the spatial processing functions underlying rodent navigation are similar to those encoding human episodic memory (Doeller et al, 2010). Spatial and nonspatial information are provided by all senses including vision. It has been suggested that visual inputs are fed to the navigational network in cortex and hippocampus through dorsal and ventral intracortical streams (Whitlock et al, 2008), but this has not been shown directly in rodents. We have used cyto- and chemoarchitectonic markers, topographic mapping of receptive fields and pathway tracing to determine in mouse visual cortex whether the lateromedial (LM) and the anterolateral fields (AL), which are the principal targets of primary visual cortex (V1) (Wang and Burkhalter, 2007) specialized for processing nonspatial and spatial visual information (Gao et al, 2006), are distinct areas with diverse connections. We have found that the LM/AL border coincides with a change in type 2 muscarinic acetylcholine receptor (m2AChR) expression in layer 4 and with the representation of the lower visual field periphery. Our quantitative analyses further show that LM strongly projects to temporal cortex as well as the lateral entorhinal cortex, which has weak spatial selectivity (Hargreaves et al, 2005). In contrast, AL has stronger connections with posterior parietal cortex, motor cortex and the spatially selective medial entorhinal cortex (Haftig et al, 2005). These results support the notion that LM and AL are architecturally, topographically and connectionally distinct areas of extrastriate visual cortex and that they are gateways for ventral and dorsal streams. PMID:21289200

  3. Aspirations of Rural Youth.

    ERIC Educational Resources Information Center

    Bajema, Duane H.; Miller, W. Wade; Williams, David L.

    2002-01-01

    Of 883 Iowa high school seniors, 60% lived in towns, 40% on farms. Both groups had a high level of congruence between educational and occupational aspirations and perceived minimal barriers to goal achievement. Farm and town students had equally diverse aspirations. (Contains 23 references.) (SK)

  4. Aspiration in Jaffna Tamil

    ERIC Educational Resources Information Center

    Thananjayarajasingham, S.

    1975-01-01

    The article accounts for the phenomenon of aspiration in Jaffna Tamil, a dialect distinct form South Indian dialects of Tamil. Not being distinctive orphonologically determined, aspiration is dealt with as a prosodic feature affecting voiceless stops in various positions. Distribution and symbolic representation are handled; kymographic evidence…

  5. Joint Aspiration (Arthrocentesis)

    MedlinePlus

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

  6. Seizure-induced plasticity of h channels in entorhinal cortical layer III pyramidal neurons.

    PubMed

    Shah, Mala M; Anderson, Anne E; Leung, Victor; Lin, Xiaodi; Johnston, Daniel

    2004-10-28

    The entorhinal cortex (EC) provides the predominant excitatory drive to the hippocampal CA1 and subicular neurons in chronic epilepsy. Discerning the mechanisms underlying signal integration within EC neurons is essential for understanding network excitability alterations involving the hippocampus during epilepsy. Twenty-four hours following a single seizure episode when there were no behavioral or electrographic seizures, we found enhanced spontaneous activity still present in the rat EC in vivo and in vitro. The increased excitability was accompanied by a profound reduction in I(h) in EC layer III neurons and a significant decline in HCN1 and HCN2 subunits that encode for h channels. Consequently, dendritic excitability was enhanced, resulting in increased neuronal firing despite hyperpolarized membrane potentials. The loss of I(h) and the increased neuronal excitability persisted for 1 week following seizures. Our results suggest that dendritic I(h) plays an important role in determining the excitability of EC layer III neurons and their associated neural networks.

  7. 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.

  8. Overactivation of NR2B-containing NMDA receptors through entorhinal-hippocampal connection initiates accumulation of hyperphosphorylated tau in rat hippocampus after transient middle cerebral artery occlusion.

    PubMed

    Xu, Cheng-Shi; Liu, An-Chun; Chen, Juan; Pan, Zhi-Yong; Wan, Qi; Li, Zhi-Qiang; Wang, Ze-Fen

    2015-08-01

    Middle cerebral artery occlusion (MCAO) induces secondary damages in the hippocampus that is remote from primary ischemic regions. Tau hyperphosphorylation is an important risk for neurodegenerative diseases. Increased tau phosphorylation has been identified in ischemic cortex, but little is known regarding the changes in the hippocampus. We showed that unilateral transient MCAO induced accumulation of hyperphosphorylated tau and concurrent dephosphorylation of glycogen synthase kinase-3β at Ser 9 in the ipsilateral hippocampus. These MCAO-induced changes were not reproduced when glutamatergic inputs from the entorhinal cortex to the hippocampus were transected; however, the changes were mimicked by intrahippocampal N-methyl-d-aspartate (NMDA) administration. Inhibition of NMDA receptor (NMDAR) subunit NR2B, but not NR2A activity in the hippocampus attenuated the accumulation of hyperphosphorylated tau and spatial cognitive impairment in MCAO rats. Together, our data suggest that overactivation of NR2B-containing NMDARs through entorhinal-hippocampal connection plays an important role in the accumulation of hyperphosphorylated tau in the hippocampus following MCAO. Glycogen synthase kinase-3β is an important protein kinase involved in NMDARs-mediated tau hyperphosphorylation. This study indicates that early inhibition of NR2B-containing NMDARs may represent a potential strategy to prevent or delay the occurrence of post-stroke dementia. Middle cerebral artery occlusion induces secondary damage in the hippocampus that is remote from primary ischemic regions. We propose that excessive activation of NR2B-containing NMDA receptors through entorhinal-hippocampal connection initiated the accumulation of hyperphosphorylated tau in the hippocampus, which subsequently induced cognitive deficit. This study provides new insights into the prospects of NR2B inhibition in stoke therapy.

  9. Medial perirhinal cortex disambiguates confusable objects.

    PubMed

    Kivisaari, Sasa L; Tyler, Lorraine K; Monsch, Andreas U; Taylor, Kirsten I

    2012-12-01

    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

  10. [Oropharyngeal dysphagia and aspiration].

    PubMed

    Barroso, Julia

    2009-11-01

    Oropharyngeal dysphagia, or inability to swallow liquids and/or solids, is one of the less well known geriatric syndromes, despite its enormous impact on functional ability, quality of life and health in affected individuals. The origin of oropharyngeal dysphagia can be structural or functional. Patients with neurodegenerative or cerebrovascular diseases and the frail elderly are the most vulnerable. The complications of oropharyngeal dysphagia are malnutrition, dehydration and aspiration, all of which are serious and provoke high morbidity and mortality. Oropharyngeal aspiration causes frequent respiratory infections and aspiration pneumonias. Antibiotic therapy must cover the usual microorganisms of the oropharyngeal flora. Oropharyngeal dysphagia should be identified early in risk groups through the use of screening methods involving clinical examination of swallowing and diagnostic confirmation methods. The simplest and most effective therapeutic intervention is adaptation of the texture of the solid and the viscosity of the liquid.

  11. Small intestine aspirate and culture

    MedlinePlus

    ... ency/article/003731.htm Small intestine aspirate and culture To use the sharing features on this page, please enable JavaScript. Small intestine aspirate and culture is a lab test to check for infection ...

  12. 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…

  13. Assessing Children's Career Aspirations

    ERIC Educational Resources Information Center

    Plummer, Donna M.

    2008-01-01

    In the past several years, "Science and Children" has invited preservice and inservice teachers to participate in national studies of students' ideas about scientists (Barman 1997), animals (Barman et al. 2000), and plants (Barman et al. 2003). You are invited to participate in an additional study that will examine children's career aspirations.…

  14. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... Your 1- to 2-Year-Old Aspiration and Biopsy: Bone Marrow KidsHealth > For Parents > Aspiration and Biopsy: Bone Marrow A A A What's in this ... ósea What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  15. Aspiration and Biopsy: Bone Marrow

    MedlinePlus

    ... A Week of Healthy Breakfasts Shyness Aspiration and Biopsy: Bone Marrow KidsHealth > For Teens > Aspiration and Biopsy: Bone Marrow A A A What's in this ... Questions What It Is Bone marrow aspirations and biopsies are performed to examine bone marrow, the spongy ...

  16. Dopaminergic enhancement of excitatory synaptic transmission in layer II entorhinal neurons is dependent on D₁-like receptor-mediated signaling.

    PubMed

    Glovaci, I; Caruana, D A; Chapman, C A

    2014-01-31

    The modulatory neurotransmitter dopamine induces concentration-dependent changes in synaptic transmission in the entorhinal cortex, in which high concentrations of dopamine suppress evoked excitatory postsynaptic potentials (EPSPs) and lower concentrations induce an acute synaptic facilitation. Whole-cell current-clamp recordings were used to investigate the dopaminergic facilitation of synaptic responses in layer II neurons of the rat lateral entorhinal cortex. A constant bath application of 1 μM dopamine resulted in a consistent facilitation of EPSPs evoked in layer II fan cells by layer I stimulation; the size of the facilitation was more variable in pyramidal neurons, and synaptic responses in a small group of multiform neurons were not modulated by dopamine. Isolated inhibitory synaptic responses were not affected by dopamine, and the facilitation of EPSPs was not associated with a change in paired-pulse facilitation ratio. Voltage-clamp recordings of α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) glutamate receptor-mediated excitatory postsynaptic currents (EPSCs) were facilitated by dopamine, but N-methyl-D-aspartate receptor-mediated currents were not. Bath application of the dopamine D₁-like receptor blocker SCH23390 (50 μM), but not the D₂-like receptor blocker sulpiride (50 μM), prevented the facilitation, indicating that it is dependent upon D₁-like receptor activation. Dopamine D₁ receptors lead to activation of protein kinase A (PKA), and including the PKA inhibitor H-89 or KT 5720 in the recording pipette solution prevented the facilitation of EPSCs. PKA-dependent phosphorylation of inhibitor 1 or the dopamine- and cAMP-regulated protein phosphatase (DARPP-32) can lead to a facilitation of AMPA receptor responses by inhibiting the activity of protein phosphatase 1 (PP1) that reduces dephosphorylation of AMPA receptors, and we found here that inhibition of PP1 occluded the facilitatory effect of dopamine. The dopamine

  17. Definition of the orbital cortex in relation to specific connections with limbic and visceral structures and other cortical regions.

    PubMed

    Price, Joseph L

    2007-12-01

    The orbitofrontal cortex is often defined topographically as the cortex on the ventral surface of the frontal lobe. Unfortunately, this definition is not consistently used, and it obscures distinct connectional and functional systems within the orbital cortex. It is difficult to interpret data on the orbital cortex that do not take these different systems into account. Analysis of cortico-cortical connections between areas in the orbital and medial prefrontal cortex indicate two distinct networks in this region. One system, called the orbital network, involves most of the areas in the central orbital cortex. The other system, has been called the medial prefrontal network, though it is actually more complex, since it includes areas on the medial wall, in the medial orbital cortex, and in the posterolateral orbital cortex. Some areas in the medial orbital cortex are involved in both networks. Connections to other brain areas support the distinction between the networks. The orbital network receives several sensory inputs, from olfactory cortex, taste cortex, somatic sensory association cortex, and visual association cortex, and is connected with multisensory areas in the ventrolateral prefrontal cortex and perirhinal cortex. The medial network has outputs to the hypothalamus and brain stem and connects to a cortical circuit that includes the rostral part of the superior temporal gyrus and dorsal bank of the superior temporal sulcus, the cingulate and retrosplenial cortex, the entorhinal and posterior parahippocampal cortex, and the dorsomedial prefrontal cortex.

  18. Fine needle aspiration cytology.

    PubMed Central

    Lever, J V; Trott, P A; Webb, A J

    1985-01-01

    Fine needle aspiration cytology is an inexpensive, atraumatic technique for the diagnosis of disease sites. This paper describes the technique and illustrates how it may be applied to the management of tumours throughout the body. The limitations of the method, the dangers of false positive reports, and the inevitability of false negative diagnoses are emphasised. In a clinical context the method has much to offer by saving patients from inappropriate operations and investigations and allowing surgeons to plan quickly and more rationally. It is an economically valuable technique and deserves greater recognition. Images PMID:2578481

  19. 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.

  20. 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…

  1. Death following crude oil aspiration.

    PubMed

    Rodriguez, M A; Martinez, M C; Martinez-Ruiz, D; Paz Giménez, M; Menéndez, M; Repetto, M

    1991-07-01

    This is a report on three deaths following oil aspiration by workers in petrol tankers. Lung aspiration was demonstrated by the presence of a yellowish-brown material in the alveolar spaces, which was difficult to identify by optic microscopy. Volatile hydrocarbons from petroleum were identified in lung samples by gas chromatography/mass spectrometry.

  2. Interhemispheric connections between the infralimbic and entorhinal cortices: The endopiriform nucleus has limbic connections that parallel the sensory and motor connections of the claustrum.

    PubMed

    Watson, Glenn D R; Smith, Jared B; Alloway, Kevin D

    2017-04-15

    We have previously shown that the claustrum is part of an interhemispheric circuit that interconnects somesthetic-motor and visual-motor cortical regions. The role of the claustrum in processing limbic information, however, is poorly understood. Some evidence suggests that the dorsal endopiriform nucleus (DEn), which lies immediately ventral to the claustrum, has connections with limbic cortical areas and should be considered part of a claustrum-DEn complex. To determine whether DEn has similar patterns of cortical connections as the claustrum, we used anterograde and retrograde tracing techniques to elucidate the connectivity of DEn. Following injections of retrograde tracers into DEn, labeled neurons appeared bilaterally in the infralimbic (IL) cortex and ipsilaterally in the entorhinal and piriform cortices. Anterograde tracer injections in DEn revealed labeled terminals in the same cortical regions, but only in the ipsilateral hemisphere. These tracer injections also revealed extensive longitudinal projections throughout the rostrocaudal extent of the nucleus. Dual retrograde tracer injections into IL and lateral entorhinal cortex (LEnt) revealed intermingling of labeled neurons in ipsilateral DEn, including many double-labeled neurons. In other experiments, anterograde and retrograde tracers were separately injected into IL of each hemisphere of the same animal. This revealed an interhemispheric circuit in which IL projects bilaterally to DEn, with the densest terminal labeling appearing in the contralateral hemisphere around retrogradely labeled neurons that project to IL in that hemisphere. By showing that DEn and claustrum have parallel sets of connections, these results suggest that DEn and claustrum perform similar functions in processing limbic and sensorimotor information, respectively. J. Comp. Neurol. 525:1363-1380, 2017. © 2016 Wiley Periodicals, Inc.

  3. 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

  4. Perirhinal cortex and temporal lobe epilepsy.

    PubMed

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

    2013-08-29

    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.

  5. Aspiration of the retrocalcaneal bursa.

    PubMed Central

    Canoso, J J; Wohlgethan, J R; Newberg, A H; Goldsmith, M R

    1984-01-01

    We aspirated the retrocalcaneal bursa in cadavers to determine the characteristics of bursal fluid. A small amount of clear, viscous fluid was constantly present in the bursa. Leucocyte count was low, and the mucin clot test was good. With the same technique we aspirated the retrocalcaneal bursae of 4 patients. Three had Reiter's syndrome; the bursal fluid was inflammatory, and symptoms promptly resolved after local corticosteroid injection. The fourth patient presented with heel pain; intracellular, positively birefringent crystals were present in the aspirate, consistent with the diagnosis of pseudogout. Images PMID:6712303

  6. 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…

  7. 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…

  8. Specific Metabolomics Adaptations Define a Differential Regional Vulnerability in the Adult Human Cerebral Cortex.

    PubMed

    Cabré, Rosanna; Jové, Mariona; Naudí, Alba; Ayala, Victoria; Piñol-Ripoll, Gerard; Gil-Villar, Maria P; Dominguez-Gonzalez, Mayelin; Obis, Èlia; Berdun, Rebeca; Mota-Martorell, Natalia; Portero-Otin, Manuel; Ferrer, Isidre; Pamplona, Reinald

    2016-01-01

    Brain neurons offer diverse responses to stresses and detrimental factors during development and aging, and as a result of both neurodegenerative and neuropsychiatric disorders. This multiplicity of responses can be ascribed to the great diversity among neuronal populations. Here we have determined the metabolomic profile of three healthy adult human brain regions-entorhinal cortex, hippocampus, and frontal cortex-using mass spectrometry-based technologies. Our results show the existence of a lessened energy demand, mitochondrial stress, and lower one-carbon metabolism (particularly restricted to the methionine cycle) specifically in frontal cortex. These findings, along with the better antioxidant capacity and lower mTOR signaling also seen in frontal cortex, suggest that this brain region is especially resistant to stress compared to the entorhinal cortex and hippocampus, which are more vulnerable regions. Globally, our results show the presence of specific metabolomics adaptations in three mature, healthy human brain regions, confirming the existence of cross-regional differences in cell vulnerability in the human cerebral cortex.

  9. Supersymmetry: aspirations and prospects

    NASA Astrophysics Data System (ADS)

    Tata, Xerxes

    2015-10-01

    The realization in the early 1980s that weak scale supersymmetry stabilizes the Higgs sector of the spectacularly successful Standard Model (SM) led several authors to explore whether low energy supersymmetry could play a role in particle physics. Among these were Richard Arnowitt, Ali Chamseddine and Pran Nath who constructed a viable locally supersymmetric grand unified theory (GUT), laying down the foundation for supergravity GUT models of particle physics. Supergravity models continue to be explored as one of the most promising extensions of the SM. After a quick overview of some of the issues and aspirations of early researchers working to bring supersymmetry into the mainstream of particle physics, we re-examine early arguments that seemed to imply that superpartners would be revealed in experiments at LEP2 or at the Tevatron. Our purpose is to assess whether the absence of any superpartners in searches at LHC8 presents a crisis for supersymmetry. Toward this end, we re-evaluate fine-tuning arguments that lead to upper bounds on (some) superpartner masses. We conclude that phenomenologically viable superpartner spectra that could arise within a high scale model tuned no worse than a few percent are perfectly possible. While no viable underlying model of particle physics that leads to such spectra has yet emerged, we show that the (supergravity-based) radiatively driven natural supersymmetry framework serves as a surrogate for a phenomenological analysis of an underlying theory with modest fine-tuning. We outline the phenomenological implications of this framework, with emphasis on those LHC and electron-positron collider signatures that might point to the underlying natural origin of gauge and Higgs boson masses. We conclude that the supergravity GUT paradigm laid down in 1982 by Arnowitt, Chamseddine and Nath, and others, remains a vibrant possibility.

  10. 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

  11. How reduction of theta rhythm by medial septum inactivation may covary with disruption of entorhinal grid cell responses due to reduced cholinergic transmission.

    PubMed

    Pilly, Praveen K; Grossberg, Stephen

    2013-01-01

    Oscillations in the coordinated firing of brain neurons have been proposed to play important roles in perception, cognition, attention, learning, navigation, and sensory-motor control. The network theta rhythm has been associated with properties of spatial navigation, as has the firing of entorhinal grid cells and hippocampal place cells. Two recent studies reduced the theta rhythm by inactivating the medial septum (MS) and demonstrated a correlated reduction in the characteristic hexagonal spatial firing patterns of grid cells. These results, along with properties of intrinsic membrane potential oscillations (MPOs) in slice preparations of medial entorhinal cortex (MEC), have been interpreted to support oscillatory interference models of grid cell firing. The current article shows that an alternative self-organizing map (SOM) model of grid cells can explain these data about intrinsic and network oscillations without invoking oscillatory interference. In particular, the adverse effects of MS inactivation on grid cells can be understood in terms of how the concomitant reduction in cholinergic inputs may increase the conductances of leak potassium (K(+)) and slow and medium after-hyperpolarization (sAHP and mAHP) channels. This alternative model can also explain data that are problematic for oscillatory interference models, including how knockout of the HCN1 gene in mice, which flattens the dorsoventral gradient in MPO frequency and resonance frequency, does not affect the development of the grid cell dorsoventral gradient of spatial scales, and how hexagonal grid firing fields in bats can occur even in the absence of theta band modulation. These results demonstrate how models of grid cell self-organization can provide new insights into the relationship between brain learning and oscillatory dynamics.

  12. Cytoarchitecture, neuronal composition, and entorhinal afferents of the flying fox hippocampus.

    PubMed

    Buhl, E H; Dann, J F

    1991-04-01

    In a comparative approach, the anatomical organization of the hippocampus was investigated in two species of megachiropteran bats, the grey-headed flying fox, Pteropus poliocephalus, and the little red flying fox, Pteropus scapulatus. In general, the cytoarchitectonic appearance of the flying fox hippocampus corresponded well with that of other mammals, revealing all major subdivisions. While the dentate fascia was trilaminated with a molecular layer, a granule cell layer, and a distinct polymorphic layer, the ammonic subfields were subdivided into stratum lacunosum molecular, stratum radiatum, stratum lucidum or mossy fiber layer (restricted to the CA3 region), pyramidal cell layer, and stratum oriens. In Ammon's horn, only subfields CA1, CA3, and CA3c were clearly discernible, whereas the CA2 region remained indistinct. In some cytoarchitectonic features, such as the dispersion of the pyramidal layer in CA1, the megachiropteran hippocampus resembled the corresponding region in primates. Five characteristic neuronal cell types of the megachiropteran hippocampus were studied in fixed slice preparations after intracellular injection with Lucifer Yellow. While the morphological appearance of CA3 pyramidal cells, horizontal stratum oriens cells, aspiny stellate cells, and mossy cells strongly resembled their counterparts in rodents, primates, and carnivores, granule cells showed an interesting variation from the nonprimate pattern. Like a subset of granule cells in the primate dentate gyrus, 75% of flying fox granule cells revealed 1-2 basal dendrites that ramified in the polymorphic layer. These processes are presumed to form the morphological substrate for recurrent excitation. Entorhinal afferents to Ammon's horn and the dentate fascia were revealed by employing the method of tract tracing in fixed tissue with the carbocyanine dye DiI. Similar to the rat and cat, but unlike the monkey, the entorhino-dentate projection in the flying fox is bilaminate, with medial

  13. Pulmonary aspiration of gastric contents.

    PubMed

    Bynum, L J; Pierce, A K

    1976-12-01

    A retrospective analysis of 50 patients who had been observed to aspirate gastric contents was performed to define better the course of patients with this syndrome. The patients invariably had a disturbance of consciousness, most commonly due to sedative drug overdose or general anesthesia. The onset of clinical signs occurred prompty after aspiration and tended to be similar in all patients, irrespective of their subsequent course or outcome. These findings usually included fever, tachypnea, diffuse rales, and serious hypoxemia. Cough, cyanosis, wheezing, and apnea were each seen in approximately one third of the cases. Apena, shock, and early severe hypoxemia were particularly ominous events. Initial roentgenograms revealed diffuse or localized alveolar infiltrates, which progressed during the next 24 to 36 hours. Subsequent clinical courses followed 3 patterns: 12 per cent of the patients died shortly after aspiration; 62 per cent had rapid clinical and radiologic improvement, with clearing, on average, within 4.5 days; 26 per cent demonstrated rapid improvement, but then had clinical and radiographic progression associated with recovery of bacterial pathogens from the sputum and a fatal outcome in more than 60 per cent. Treatment from the outset by adrenocortical steroids or antimicrobial agents had no demonstrable effect on the outcome. The clinical features of aspiration of gastric contents are characteristic and distinguish it from other forms of aspiration-related lung disease.

  14. [Perioperative Pulmonary Aspiration: Preface and Comments].

    PubMed

    Asai, Takashi

    2016-01-01

    Since the risk of pulmonary aspiration was recognized in obstetric anesthesia in 1930's, numerous efforts have been made to reduce the incidence and severity of perioperative pulmonary aspiration: preoperative fasting, preoperative assessment of risk factors in perioperative pulmonary aspiration, emptying the stomach, rapid-sequence induction of anesthesia with cricoid pressure, and the use of a cuffed tracheal tube. With these efforts, the incidence of pulmonary aspiration has been reduced drastically, and aspiration is now rare. Nevertheless, recent large studies have shown that perioperative pulmonary aspiration is the main cause of anesthesia-related death or irreversible brain damage. In this special issue, experts summarize the current state of perioperative pulmonary aspiration, its diagnosis and treatment, risk factors of pulmonary aspiration, preoperative preventative methods, and appropriate anesthesia methods and airway management in patients at increased risk of pulmonary aspiration.

  15. Specific Metabolomics Adaptations Define a Differential Regional Vulnerability in the Adult Human Cerebral Cortex

    PubMed Central

    Cabré, Rosanna; Jové, Mariona; Naudí, Alba; Ayala, Victoria; Piñol-Ripoll, Gerard; Gil-Villar, Maria P.; Dominguez-Gonzalez, Mayelin; Obis, Èlia; Berdun, Rebeca; Mota-Martorell, Natalia; Portero-Otin, Manuel; Ferrer, Isidre; Pamplona, Reinald

    2016-01-01

    Brain neurons offer diverse responses to stresses and detrimental factors during development and aging, and as a result of both neurodegenerative and neuropsychiatric disorders. This multiplicity of responses can be ascribed to the great diversity among neuronal populations. Here we have determined the metabolomic profile of three healthy adult human brain regions—entorhinal cortex, hippocampus, and frontal cortex—using mass spectrometry-based technologies. Our results show the existence of a lessened energy demand, mitochondrial stress, and lower one-carbon metabolism (particularly restricted to the methionine cycle) specifically in frontal cortex. These findings, along with the better antioxidant capacity and lower mTOR signaling also seen in frontal cortex, suggest that this brain region is especially resistant to stress compared to the entorhinal cortex and hippocampus, which are more vulnerable regions. Globally, our results show the presence of specific metabolomics adaptations in three mature, healthy human brain regions, confirming the existence of cross-regional differences in cell vulnerability in the human cerebral cortex. PMID:28008307

  16. [Prevention of Perioperative Aspiration Pneumonitis].

    PubMed

    Fukuda, Kazuhiko

    2016-01-01

    To prevent perioperative aspiration pneumonitis, it is necessary to reduce the volume and acidity of gastric content. The guideline for preoperative fasting published by Japanese Society of Anesthesiologists recommends fasting from intake of clear fluids, breast milk and nonhuman milk at least 2h, 4h and 6h, respectively, before elective procedures requiring general anesthesia, regional anesthesia or sedation/analgesia. Gastrointestinal stimulants, histamine-2 receptor antagonists, proton pump inhibitors, antacids, antiemetics, anticholinergics are effective for reduction of the volume or acidity of gastric content. However, the routine preoperative use of these drugs to reduce the risk of pulmonary aspiration in patients who have no apparent increased risk for pulmonary aspiration is not recommended.

  17. 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.

  18. 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

  19. Dermabrasion using an ultrasonic surgical aspirator.

    PubMed

    Ito, Y; Kondo, S; Sumiya, N; Yoshii, M; Otani, K; Wako, M

    1996-04-01

    We used an ultrasonic surgical aspirator on the epidermal surface to perform dermabrasion instead of the conventional motor-driven grinder. It was determined on histologic examination that it is possible to fragment the epidermis with greater selectively using the ultrasonic surgical aspirator. Abrasion also can be performed safely on spotty lesions and intricate, problematic regions with the ultrasonic surgical aspirator. We feel that the ultrasonic surgical aspirator is a promising device for use in dermabrasion.

  20. Crowning achievement: a case of dental aspiration.

    PubMed

    Mark, Nicholas M; Lessing, Juan N; Çoruh, Başak

    2015-12-01

    Aspiration of foreign bodies during dental procedures is a rare but potentially serious complication. We present a case of a 75-year-old man who aspirated a dental crown requiring flexible bronchoscopic retrieval. We discuss the risk factors for aspiration, the radiographic features of diagnosis, and the techniques for management and retrieval.

  1. Crowning achievement: a case of dental aspiration

    PubMed Central

    Mark, Nicholas M.; Lessing, Juan N.; Çoruh, Başak

    2015-01-01

    Aspiration of foreign bodies during dental procedures is a rare but potentially serious complication. We present a case of a 75-year-old man who aspirated a dental crown requiring flexible bronchoscopic retrieval. We discuss the risk factors for aspiration, the radiographic features of diagnosis, and the techniques for management and retrieval. PMID:26649115

  2. 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…

  3. The orbitofrontal cortex: novelty, deviation from expectation, and memory.

    PubMed

    Petrides, Michael

    2007-12-01

    The orbitofrontal cortex is strongly connected with limbic areas of the medial temporal lobe that are critically involved in the establishment of declarative memories (entorhinal and perirhinal cortex and the hippocampal region) as well as the amygdala and the hypothalamus that are involved in emotional and motivational states. The present article reviews evidence regarding the role of the orbitofrontal cortex in the processing of novel information, breaches of expectation, and memory. Functional neuroimaging evidence is provided that there is a difference between the anterior and posterior orbitofrontal cortex in such processing. Exposure to novel information gives rise to a selective increase of activity in the granular anterior part of the orbitofrontal cortex (area 11) and this activity increases when subjects attempt to encode this information in memory. If the stimuli violate expectations (e.g., inspection of graffiti-like stimuli in the context of other regular stimuli) or are unpleasant (i.e., exposure to the sounds of car crashes), there is increased response in the posteromedial agranular/dysgranular area 13 of the orbitofrontal region. The anatomic data provide a framework within which to understand these functional neuroimaging findings.

  4. Silent aspiration: what do we know?

    PubMed

    Ramsey, Deborah; Smithard, David; Kalra, Lalit

    2005-01-01

    Although clinically evident aspiration is common in subjects with dysphagia, a significant proportion may aspirate silently, i.e., without any outward signs of swallowing difficulty. This article reviews the literature on the prevalence, etiology, and prognostic significance of silent aspiration. An electronic database search was performed using silent aspiration, aspiration, dysphagia, and stroke as search terms, together with hand-searching of articles. Silent aspiration has been described in many conditions and subgroups of patients (including normal individuals), using a number of detection methods, making comparisons a challenge. The best data are for acute stroke, in which 2%-25% of patients may aspirate silently. Mechanisms associated with silent aspiration may include central or local weakness/incoordination of the pharyngeal musculature, reduced laryngopharyngeal sensation, impaired ability to produce a reflexive cough, and low substance P or dopamine levels. In terms of prognosis, silent aspiration has been associated with increased morbidity and mortality in many but not all studies. However, some degree of silent aspiration at night may be normal in healthy individuals. The phenomenon of silent aspiration is poorly understood and further research is needed to improve methods of detection and thereby better define its prevalence and prognostic significance.

  5. [Pathophysiology and Therapeutic Approach of Pulmonary Aspiration].

    PubMed

    Uchida, Kanji

    2016-01-01

    Pulmonary aspiration is one of the serious adverse events in general anesthesia. Aspiration induced lung injury varies according to the nature of the contents of aspirates (acid or small particles in gastrointestinal tract, bile acid), amount of aspirates, and host-defense status. Early inflammatory responses to acid and small particles from gastrointestinal contents are categorized as aspiration pneumonitis causing rapid respiratory deterioration with early restoration of lung injury within a couple of days. Late phase lung injury is usually "aspiration pneumonia" caused by bacteria colonized in the aspirates. Treatment mainstream is to support respiratory function until the lung resolves from injury. Extracorporeal membrane oxygenation is another promising therapeutic option for cases with severe lung damage to keep the "lung rest" during fulminant lung injury, avoiding further lung damage by injurious ventilation. Empirical administration of antibiotics covering wide spectrum followed by meticulous bacteriological studies to either de-escalate or discontinue antibiotics is crucial.

  6. Aspirations of Latina adolescent suicide attempters

    PubMed Central

    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 in youths’ behavior can be deleterious, such as when adolescents manifest suicidal behaviors. We examined aspirations expressed by 12 Latina adolescent suicide attempters and their parents and compared them to 12 non-suicidal Latinas and parents. Qualitative analyses revealed that incongruence of aspirations between girls and their parents were greater among suicidal teens. Suicidal and non-suicidal Latinas presented contrasting aspirations: the former on gaining independence and the latter on completing their education and pursuing careers. Findings may inform developmental research and ways in which clinicians and policymakers can help Latinas achieve their own and their parents’ aspirations. PMID:24013464

  7. Aspiration of a speaking valve

    PubMed Central

    Schembri, John; Cortis, Kelvin; Mallia Azzopardi, Charles; Montefort, Stephen

    2013-01-01

    Foreign body aspiration (FBA) is a relatively common and serious condition that can result in a spectrum of presentations ranging from incidental to acutely life-threatening. Described here is a case of aspiration of a tracheo-oesophageal speaking valve through a permanent tracheostomy that went unnoticed for a number of years, and an overview of the technique used for its removal. A 70-year-old ex-heavy smoker with a permanent tracheo-oesophageal fistula presented with a relatively recent history of increasing shortness of breath, sputum purulence and haemoptysis. Further investigation with a CT scan and bronchoscopy revealed the presence of a foreign body within his right lower lobe bronchus which was later removed by advancing a flexible bronchoscope over a rigid one. PMID:23861275

  8. Electrophysiological and morphological properties of neurons in layer 5 of the rat postrhinal cortex.

    PubMed

    Sills, Joseph B; Connors, Barry W; Burwell, Rebecca D

    2012-09-01

    The postrhinal (POR) cortex of the rat is homologous to the parahippocampal cortex of the primate based on connections and other criteria. POR provides the major visual and visuospatial input to the hippocampal formation, both directly to CA1 and indirectly through connections with the medial entorhinal cortex. Although the cortical and hippocampal connections of the POR cortex are well described, the physiology of POR neurons has not been studied. Here, we examined the electrical and morphological characteristics of layer 5 neurons from POR cortex of 14- to 16-day-old rats using an in vitro slice preparation. Neurons were subjectively classified as regular-spiking (RS), fast-spiking (FS), or low-threshold spiking (LTS) based on their electrophysiological properties and similarities with neurons in other regions of neocortex. Cells stained with biocytin included pyramidal cells and interneurons with bitufted or multipolar dendritic patterns. Similarity analysis using only physiological data yielded three clusters that corresponded to FS, LTS, and RS classes. The cluster corresponding to the FS class was composed entirely of multipolar nonpyramidal cells, and the cluster corresponding to the RS class was composed entirely of pyramidal cells. The third cluster, corresponding to the LTS class, was heterogeneous and included both multipolar and bitufted dendritic arbors as well as one pyramidal cell. We did not observe any intrinsically bursting pyramidal cells, which is similar to entorhinal cortex but unlike perirhinal cortex. We conclude that POR includes at least two major classes of neocortical inhibitory interneurons, but has a functionally restricted cohort of pyramidal cells.

  9. 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.

  10. Preventing Effect of L-Type Calcium Channel Blockade on Electrophysiological Alterations in Dentate Gyrus Granule Cells Induced by Entorhinal Amyloid Pathology

    PubMed Central

    Pourbadie, Hamid Gholami; Naderi, Nima; Mehranfard, Nasrin; Janahmadi, Mahyar; Khodagholi, Fariba; Motamedi, Fereshteh

    2015-01-01

    The entorhinal cortex (EC) is one of the earliest affected brain regions in Alzheimer’s disease (AD). EC-amyloid pathology induces synaptic failure in the dentate gyrus (DG) with resultant behavioral impairment, but there is little known about its impact on neuronal properties in the DG. It is believed that calcium dyshomeostasis plays a pivotal role in the etiology of AD. Here, the effect of the EC amyloid pathogenesis on cellular properties of DG granule cells and also possible neuroprotective role of L-type calcium channel blockers (CCBs), nimodipine and isradipine, were investigated. The amyloid beta (Aβ) 1–42 was injected bilaterally into the EC of male rats and one week later, electrophysiological properties of DG granule cells were assessed. Voltage clamp recording revealed appearance of giant sIPSC in combination with a decrease in sEPSC frequency which was partially reversed by CCBs in granule cells from Aβ treated rats. EC amyloid pathogenesis induced a significant reduction of input resistance (Rin) accompanied by a profound decreased excitability in the DG granule cells. However, daily administration of CCBs, isradipine or nimodipine (i.c.v. for 6 days), almost preserved the normal excitability against Aβ. In conclusion, lower tendency to fire AP along with reduced Rin suggest that DG granule cells might undergo an alteration in the membrane ion channel activities which finally lead to the behavioral deficits observed in animal models and patients with early-stage Alzheimer’s disease. PMID:25689857

  11. Human P301L-Mutant Tau Expression in Mouse Entorhinal-Hippocampal Network Causes Tau Aggregation and Presynaptic Pathology but No Cognitive Deficits

    PubMed Central

    Harris, Julie A.; Koyama, Akihiko; Maeda, Sumihiro; Ho, Kaitlyn; Devidze, Nino; Dubal, Dena B.; Yu, Gui-Qiu; Masliah, Eliezer; Mucke, Lennart

    2012-01-01

    Accumulation of hyperphosphorylated tau in the entorhinal cortex (EC) is one of the earliest pathological hallmarks in patients with Alzheimer’s disease (AD). It can occur before significant Aβ deposition and appears to “spread” into anatomically connected brain regions. To determine whether this early-stage pathology is sufficient to cause disease progression and cognitive decline in experimental models, we overexpressed mutant human tau (hTauP301L) predominantly in layer II/III neurons of the mouse EC. Cognitive functions remained normal in mice at 4, 8, 12 and 16 months of age, despite early and extensive tau accumulation in the EC. Perforant path (PP) axon terminals within the dentate gyrus (DG) contained abnormal conformations of tau even in young EC-hTau mice, and phosphorylated tau increased with age in both the EC and PP. In old mice, ultrastructural alterations in presynaptic terminals were observed at PP-to-granule cell synapses. Phosphorylated tau was more abundant in presynaptic than postsynaptic elements. Human and pathological tau was also detected within hippocampal neurons of this mouse model. Thus, hTauP301L accumulation predominantly in the EC and related presynaptic pathology in hippocampal circuits was not sufficient to cause robust cognitive deficits within the age range analyzed here. PMID:23029293

  12. Convergence of entorhinal and CA3 inputs onto pyramidal neurons and interneurons in hippocampal area CA1--an anatomical study in the rat.

    PubMed

    Kajiwara, Riichi; Wouterlood, Floris G; Sah, Anupam; Boekel, Amber J; Baks-te Bulte, Luciënne T G; Witter, Menno P

    2008-01-01

    The entorhinal cortex (EC) conveys information to hippocampal field CA1 either directly by way of projections from principal neurons in layer III, or indirectly by axons from layer II via the dentate gyrus, CA3, and Schaffer collaterals. These two pathways differentially influence activity in CA1, yet conclusive evidence is lacking whether and to what extent they converge onto single CA1 neurons. Presently we studied such convergence. Different neuroanatomical tracers injected into layer III of EC and into CA3, respectively, tagged simultaneously the direct entorhino-hippocampal fibers and the indirect innervation of CA1 neurons by Schaffer collaterals. In slices of fixed brains we intracellularly filled CA1 pyramidal cells and interneurons in stratum lacunosum-moleculare (LM) and stratum radiatum (SR). Sections of these slices were scanned in a confocal laser scanning microscope. 3D-reconstruction was used to determine whether boutons of the labeled input fibers were in contact with the intracellularly filled neurons. We analyzed 12 pyramidal neurons and 21 interneurons. Perforant path innervation to pyramidal neurons in our material was observed to be denser than that from CA3. All pyramidal neurons and 17 of the interneurons received contacts of both perforant pathway and Schaffer input on their dendrites and cell bodies. Four interneurons, which were completely embedded in LM, received only labeled perforant pathway input. Thus, we found convergence of both projection systems on single CA1 pyramidal and interneurons with dendrites that access the layers where perforant pathway fibers and Schaffer collaterals end.

  13. Strategies for prophylaxis and treatment for aspiration.

    PubMed

    Kalinowski, Christopher Peter Henry; Kirsch, Jeffery Robert

    2004-12-01

    The absolute incidence of aspiration is difficult to define because of its relatively low occurrence and difficulty in diagnosis. The gastric volume predisposing to aspiration is larger than 30 ml. Fasting times for fluids have reduced; however, a large meal may require 9 hours of preoperative fasting. Preoperative carbohydrate-enriched beverages may attenuate postoperative catabolism. Aspiration occurs most frequently during induction and laryngoscopy. Awake fibre-optic intubation may be a suitable alternative in high-risk cases for aspiration. The role of cricoid pressure in anaesthesia needs re-evaluation as radiological and clinical evidence suggest that it may be ineffective and may impede intubation and ventilation. Chemoprophylaxis does not reduce the severity of aspiration pneumonitis as gastric bile is unaffected by these agents and induces a worse pneumonitis than gastric acid. Patients may be discharged home 2 hours after aspirating provided they are clinically unaffected and have postoperative surveillance.

  14. Aspiration thrombectomy in concert with stent thrombectomy.

    PubMed

    Dumont, Travis M; Mokin, Maxim; Sorkin, Grant C; Levy, Elad I; Siddiqui, Adnan H

    2013-07-12

    In the SWIFT and TREVO 2 trials, aspiration thrombectomy was not able to be performed. Outside these studies, in post-market application, the interventionist can use aspiration thrombectomy in addition to stent device thrombectomy. This technique is described in detail in the present report. Combined aspiration/stentriever thrombectomy may improve recanalization efforts, simplify a second thrombectomy attempt if necessary and may limit distal embolization.

  15. Aspiration

    MedlinePlus

    ... diagnosis of benign lesions. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ... patient with liver disease. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine . 24th ed. Philadelphia, PA: ...

  16. 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?

  17. ASPIRE - the first British student rocket programme

    NASA Astrophysics Data System (ADS)

    Baker, Adam M.; Murray, J.; Osborne, R.; Macfarlane, J.

    ASPIRE is the first British programme aiming to create and develop a small scale, hybrid engine powered launch vehicle. The project is also unique because it is a wholly amateur effort, volunteer team members having little or no professional experience in launch vehicle design, manufacture and operations; and being a mix of students and young professionals. Participants have the opportunity to develop their experience in the engineering/scientific, operational and management areas which ASPIRE encompasses. This experience will then be validated through the launching of a series of test vehicles, culminating in a demonstration of the orbital insertion of a payload by the year 2000. ASPIRE aims to eventually return an independent orbital launch capability to Britain, for the first time since 1971. This paper outlines the technical details of the ASPIRE rockets, including: airframe design and manufacture, hybrid motor design and testing, avionics development, guidance and recovery techniques, range safety practise and marketing and fund-raising. It will also cover the organisation and ethos of the programme in general. A timeline for the ASPIRE programme will be detailed, from the original ASPIRE 1 construction and launch in 1991/1992, evolving through the current series of ASPIRE Development Vehicles (ADVs), to ASPIRE 2 and 3, where the hybrid motor and other engineering subsystems are to be integrated on an increasing scale. The proposed union of an ASPIRE 3 vehicle with an Australian AUSROC launcher to achieve the 2000 orbital goal will also be covered.

  18. Selective Degeneration of Entorhinal-CA1 Synapses in Alzheimer's Disease via Activation of DAPK1

    PubMed Central

    Shu, Shu; Zhu, Houze; Tang, Na; Chen, Wenting; Li, Xinyan; Li, Hao; Pei, Lei; Liu, Dan; Mu, Yangling; Tian, Qing

    2016-01-01

    Excitatory pyramidal neurons in the entorhinal cortical layer II region (ECIIPN) form functional excitatory synapses with CA1 parvalbumin inhibitory neurons (CA1PV) and undergo selective degeneration in the early stages of Alzheimer's disease (AD). Here, we show that death-associated protein kinase 1 (DAPK1) is selectively activated in ECIIPN of AD mice. Inhibition of DAPK1 by deleting a catalytic domain or a death domain of DAPK1 rescues the ECIIPN-CA1PV synaptic loss and improves spatial learning and memory in AD mice. This study demonstrates that activation of DAPK1 in ECIIPN contributes to a memory loss in AD and hence warrants a promising target for the treatment of AD. SIGNIFICANCE STATEMENT Our recent study reported that excitatory pyramidal neurons in the entorhinal cortical layer II region (ECIIPN) target to CA1 parvalbumin-type inhibitory neurons (CA1PV) at a direct pathway and are one of the most vulnerable brain cells that are selectively degenerated in the early stage of Alzheimer's disease (AD). Our present study shows that death-associated protein kinase 1 (DAPK1) is selectively activated in ECIIPN of AD mice. Inhibition of DAPK1 by deleting a catalytic domain or a death domain of DAPK1 rescues the ECIIPN-CA1PV synaptic loss and improves spatial learning and memory in the early stage of AD. These data not only demonstrate a crucial molecular event for synaptic degeneration but also provide a therapeutic target for the treatment of AD. PMID:27798139

  19. 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…

  20. Effect of aging on cough and swallowing reflexes: implications for preventing aspiration pneumonia.

    PubMed

    Ebihara, Satoru; Ebihara, Takae; Kohzuki, Masahiro

    2012-02-01

    The impairment of airway protective reflexes, i.e., swallowing and cough reflexes, is thought to be one of the major causes for aspiration pneumonia in older people. Restoration of cough and swallowing reflexes in the elderly is key to preventing aspiration pneumonia in the elderly. Although, the medical literature has asserted that cough and swallowing are controlled primarily by the brainstem, recent advances in human brain imaging has provided evidence that cortical and subcortical structures play critical roles in cough and swallowing control. Because of their nature, reflexive cough and swallowing activate both sensory and motor areas in the cortex. In both protective reflexes, the sensory component, including sensory cortex in reflexive circuits, seems to be more vulnerable to aging than the motor component, including the motor cortex. Therefore, the strategy to restore cough and swallowing reflexes should be focused on compensations of sensory components in these reflexive circuits. Remedies to enhance sensory nerve terminals and sensory cortical areas related to these reflexes might be useful to prevent aspiration pneumonia in the elderly.

  1. 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…

  2. 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.

  3. Endometrial aspiration cytology in gynecological disorders

    PubMed Central

    Jadhav, Meenal V.; Phatke, Anjali S.; Kadgi, Nalini Vinayak; Rane, Sharda R.; Kulkarni, Kalpana K.

    2016-01-01

    Context: Endometrial aspiration is not a popular modality for the study of the endometrium despite its simplicity and potential utility. Aim: The present study was aimed at evaluating the utility of endometrial aspiration in various gynecological disorders. Materials and Methods: In this diagnostic accuracy study, 55 prospectively registered women with various gynecological disorders were evaluated clinically and subjected to endometrial aspiration cytology and study of endometrial histology. Endometrial aspiration was performed by infant feeding tube in 10 cases and intra cath cannula in 45 cases. The slides were stained with rapid Papanicolaou (PAP) stain and Leishman stain. Results: Endometrial aspiration cytology showed 90% and 94.6% sampling adequacy with infant feeding tube and intra cath cannula, respectively. Intra cath cannula was very convenient to handle and superior to infant feeding tube in aspirating the endometrium. Of the two stains used, rapid PAP stain was less time-consuming and superior to Leishman stain in studying the nuclear details. Leishman stain was helpful in detecting cytoplasmic vacuoles of secretory endometrium. Overall diagnostic accuracy of endometrial cytology was 90.4% while that for morphological hormonal evaluation was 97.6%. It enjoyed a sensitivity of 91.66%, a specificity of 88.23%, positive predictive value of 94.28%, and negative predictive value of 83.33%. Conclusion: Intra cath cannula emerged as an inexpensive, effective, and convenient device for endometrial aspiration. Endometrial aspiration proved to be a fairly effective, simple, and informative diagnostic modality. PMID:27011435

  4. 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…

  5. Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid

    MedlinePlus

    ... Index A-Z Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid An ultrasound-guided thyroid biopsy ... Thyroid? What is Ultrasound-Guided Fine Needle Aspiration Biopsy of the Thyroid? During a fine needle aspiration ...

  6. Aspiration pneumonia in dogs: pathophysiology, prevention, and diagnosis.

    PubMed

    Schulze, Heidi M; Rahilly, Louisa J

    2012-12-01

    Aspiration pneumonia and aspiration pneumonitis are associated with significant morbidity in veterinary and human medicine. A variety of medical conditions and medications can predispose patients to aspiration, and every precaution should be taken to prevent aspiration from occurring. For dogs that aspirate oral or gastric contents and subsequently develop pneumonia, monitoring and supportive care are imperative. This article discusses the pathophysiology, prevention, and diagnosis of aspiration pneumonia.

  7. SUBCORTICAL CONNECTIONS OF THE PERIRHINAL, POSTRHINAL, AND ENTORHINAL CORTICES OF THE RAT. I. AFFERENTS

    PubMed Central

    Pereira, Inês Tomás; Agster, Kara L.; Burwell, Rebecca D.

    2016-01-01

    In this study we characterized the subcortical afferents for the rat PER areas 35 and 36, POR, and the lateral and medial entorhinal areas (LEA and MEA). We analyzed 33 retrograde tract-tracing experiments distributed across the five regions. For each experiment, we estimated the total numbers, percentages, and densities of labeled cells in 36 subcortical structures and nuclei distributed across septum, basal ganglia, claustrum, amygdala, olfactory structures, thalamus, and hypothalamus. We found that the complement of subcortical inputs differs across the five regions, especially the PER and POR. The PER receives input from the reuniens, suprageniculate, and medial geniculate thalamic nuclei as well as the amygdala. Overall, the subcortical inputs to the PER are consistent with a role in perception, multimodal processing, and the formation of associations that include the motivational significance of individual items and objects. Subcortical inputs to the POR were dominated by the dorsal thalamus, particularly the lateral posterior nucleus, a region implicated in visuospatial attention. The complement of subcortical inputs to the POR is consistent with a role in representing and monitoring the local spatial context. We also report that, in addition to the PER, the LEA and the medial band of the MEA also receive strong amygdala input. In contrast, subcortical input to the POR and the MEA lateral band includes much less amygdala input and is dominated by dorsal thalamic nuclei, particularly nuclei involved in spatial information processing. Like the cortical inputs, the patterns of subcortical inputs to these regions are consistent both with the view that the dorsal hippocampus is important for spatial cognition and the ventral hippocampus is important for affective cognition, and the view that they provide considerable functional integration. We conclude that the patterns of subcortical inputs to the PER, POR, and the entorhinal LEA and MEA provide further evidence

  8. Surgical jejunostomy in aspiration risk patients.

    PubMed Central

    Weltz, C R; Morris, J B; Mullen, J L

    1992-01-01

    One hundred patients underwent laparotomy for independent jejunal feeding tube placement. Neurologic disease was present in 50%, and obtundation (28) and oropharyngeal dysmotility (25) were the most common indications for enteral feeding. The post-pyloric route was chosen because of aspiration risk in almost all (94%) patients. Postoperative (30-day) mortality rate was 21%, because of cardiopulmonary failure in most (18). One death resulted directly from aspiration of tube feeds. Two surgical complications required reoperation: one wound dehiscence and one small bowel obstruction. Four wound infections occurred. Two patients underwent reoperation after tube removal, and four tubes required fluoroscopically guided reinsertion for peritubular drainage (2), removal (1), and occlusion (1). Aspiration pneumonia was present in 18 patients preoperatively and in eight postoperatively. None of the patients with feeding-related preoperative aspiration pneumonia (13) had a recurrence while fed by jejunostomy. Three patients developed postoperative aspiration pneumonia before initiation of jejunostomy feedings. Jejunostomy may be performed with low morbidity rate and substantial reduction of feeding-related aspiration pneumonia, and is the feeding route of choice in aspiration risk patients. PMID:1546899

  9. Coronary air embolism treated with aspiration catheter

    PubMed Central

    Patterson, M S; Kiemeneij, F

    2005-01-01

    Coronary air embolism remains a recognised complication of coronary catheterisation despite a strong emphasis on prevention. Current treatment consists of supportive measures with 100% oxygen and analgesia. Recent case reports describe the use of mechanical treatments aimed at dispersing or removing the air embolus with variable success. A case of coronary air embolism causing an acute coronary syndrome is described that was definitively treated with an aspiration system. The effectiveness of the aspiration system in the distal section of an obtuse marginal artery indicates that such dedicated aspiration systems may prove useful in the standard treatment of air embolism. PMID:15831621

  10. Coronary air embolism treated with aspiration catheter.

    PubMed

    Patterson, M S; Kiemeneij, F

    2005-05-01

    Coronary air embolism remains a recognised complication of coronary catheterisation despite a strong emphasis on prevention. Current treatment consists of supportive measures with 100% oxygen and analgesia. Recent case reports describe the use of mechanical treatments aimed at dispersing or removing the air embolus with variable success. A case of coronary air embolism causing an acute coronary syndrome is described that was definitively treated with an aspiration system. The effectiveness of the aspiration system in the distal section of an obtuse marginal artery indicates that such dedicated aspiration systems may prove useful in the standard treatment of air embolism.

  11. Lack of effect of entorhinal kindling on L-(/sup 3/H)glutamic acid presynaptic uptake and postsynaptic binding in hippocampus

    SciTech Connect

    Slevin, J.T.; Ferrara, L.P.

    1985-07-01

    Sodium-independent L-(/sup 3/H)glutamic acid binding and sodium-dependent L-(/sup 3/H)glutamic acid high affinity uptake were measured in hippocampal membranes of rats administered electroshock seizures or kindled to class 5 seizures by entorhinal cortical stimulation. There were no differences in these glutamatergic synaptic markers among electroshocked, kindled, or surgical control animals. Entorhinal kindling is not a reflection of activity-regulated facilitation of perforant path glutamatergic neurotransmission.

  12. Properties of doublecortin-(DCX)-expressing cells in the piriform cortex compared to the neurogenic dentate gyrus of adult mice.

    PubMed

    Klempin, Friederike; Kronenberg, Golo; Cheung, Giselle; Kettenmann, Helmut; Kempermann, Gerd

    2011-01-01

    The piriform cortex receives input from the olfactory bulb and (via the entorhinal cortex) sends efferents to the hippocampus, thereby connecting the two canonical neurogenic regions of the adult rodent brain. Doublecortin (DCX) is a cytoskeleton-associated protein that is expressed transiently in the course of adult neurogenesis. Interestingly, the adult piriform cortex, which is usually considered non-neurogenic (even though some reports exist that state otherwise), also contains an abundant population of DCX-positive cells. We asked how similar these cells would be to DCX-positive cells in the course of adult hippocampal neurogenesis. Using BAC-generated transgenic mice that express GFP under the DCX promoter, we studied DCX-expression and electrophysiological properties of DCX-positive cells in the mouse piriform cortex in comparison with the dentate gyrus. While one class of cells in the piriform cortex indeed showed features similar to newly generated immature granule neurons, the majority of DCX cells in the piriform cortex was mature and revealed large Na+ currents and multiple action potentials. Furthermore, when proliferative activity was assessed, we found that all DCX-expressing cells in the piriform cortex were strictly postmitotic, suggesting that no DCX-positive "neuroblasts" exist here as they do in the dentate gyrus. We conclude that DCX in the piriform cortex marks a unique population of postmitotic neurons with a subpopulation that retains immature characteristics associated with synaptic plasticity. DCX is thus, per se, no marker of neurogenesis but might be associated more broadly with plasticity.

  13. Healthcare-associated Pneumonia and Aspiration Pneumonia

    PubMed Central

    Komiya, Kosaku; Ishii, Hiroshi; Kadota, Jun-ichi

    2015-01-01

    Healthcare-associated pneumonia (HCAP) is a new concept of pneumonia proposed by the American Thoracic Society/Infectious Diseases Society of America in 2005. This category is located between community-acquired pneumonia and hospital-acquired pneumonia with respect to the characteristics of the causative pathogens and mortality, and primarily targets elderly patients in healthcare facilities. Aspiration among such patients is recognized to be a primary mechanism for the development of pneumonia, particularly since the HCAP guidelines were published. However, it is difficult to manage patients with aspiration pneumonia because the definition of the condition is unclear, and the treatment is associated with ethical aspects. This review focused on the definition, prevalence and role of aspiration pneumonia as a prognostic factor in published studies of HCAP and attempted to identify problems associated with the concept of aspiration pneumonia. PMID:25657850

  14. Aspiration pneumonia in children: an iconographic essay.

    PubMed

    de Oliveira, Gabriel Antonio; Pessanha, Laís Bastos; Guerra, Luiz Felipe Alves; Martins, Diego Lima Nava; Rondina, Ronaldo Garcia; Silva, Jamine Ronacher Passos

    2015-01-01

    In most cases of aspiration pneumonia in children, the disease is specific to this age group. Clinical and radiological correlation is essential for the diagnosis. The present pictorial essay is aimed at showing typical images of the most common etiologies.

  15. Efferent connections of the rostral portion of medial agranular cortex in rats.

    PubMed

    Reep, R L; Corwin, J V; Hashimoto, A; Watson, R T

    1987-08-01

    This study of the rostral part of medial agranular cortex (AGm) was undertaken with two principal aims in mind. First, to delineate the efferent connections of AGm and compare these with the pattern of afferents defined by us in a previous study. Second, to provide a firmer basis for anatomical and functional comparisons with cortical regions in monkeys. Autoradiographic, horseradish peroxidase, and fiber degeneration techniques were used. Rostral AGm has a variety of corticocortical connections--with lateral agranular motor cortex (AGl); visual, auditory, and somatic sensory regions; and limbic/paralimbic areas including orbital, insular, perirhinal, entorhinal, retrosplenial and presubicular fields. The projections to orbital, perirhinal and entorhinal cortices are bilateral. Thalamic projections of rostral AGm are concentrated in the ventral lateral, central lateral, paracentral, mediodorsal and ventromedial nuclei. Moderate terminal fields are consistently seen in the reticular, anteromedial, central medial, gelatinosus, parafascicular, and posterior nuclei. More caudal projections reach the central gray, superior colliculus and pontine gray. The efferents of the adjacent AGl were also examined. Although many of these overlapped those of rostral AGm, there were no efferents to visual or auditory cortex and limbic/paralimbic projections were reduced. Thalamic projections were more focused in the ventral lateral and posterior nuclei and there were no terminal fields in the central gray or superior colliculus. Based on its afferent and efferent connections, role in contralateral neglect, and the results of microstimulation studies, rostral AGm can be viewed as a multimodal association area with strong ties to the motor system. On these structural and functional grounds, rostral AGm bears certain striking resemblances to the frontal eye field, supplementary motor, and arcuate premotor areas of monkey cortex.

  16. To Aspire: A Systematic Reflection on Understanding Aspirations in Higher Education

    ERIC Educational Resources Information Center

    Gale, Trevor; Parker, Stephen

    2015-01-01

    Aspirations for higher education by people from low socioeconomic status backgrounds are now a focus of government policy in many OECD nations. This is part of a global trend emphasizing the perceived benefits of "raising" aspirations among under-represented groups as a social inclusion strategy to widen university participation, but…

  17. A modified-simple technique of removing the lens cortex during cataract surgery

    PubMed Central

    Han, Kyung Eun; Han, Se Hoon; Lim, Dongkwon; Shin, Min Chul

    2017-01-01

    We describe here a surgical technique of removing the remaining cortex after phacoemulsification without performing the conventional irrigation/aspiration (I/A) procedure. In this technique, the remaining cortex attached to the posterior capsule was separated and dissected into several pieces by continuous irrigation with balanced salt solution, which was supplied through a syringe attached to a bent, blunt-tip needle. Approximately, 10 s of manual irrigation separated most of the remaining cortex from the posterior capsule. Then, the capsular bag was inflated with an ophthalmic viscoelastic device (OVD), and this pushed the separated cortex toward the capsular fornix mechanically. An intraocular lens was inserted into the capsular bag, following which the remaining cortex and OVD were removed concomitantly using an automated I/A handpiece. This technique is a simple and easy maneuver to remove the cortex from all areas, including the subincisional area, and reduce the possibility of a posterior capsule tear. PMID:28300744

  18. Low distribution of synaptic vesicle protein 2A and synaptotagimin-1 in the cerebral cortex and hippocampus of spontaneously epileptic rats exhibiting both tonic convulsion and absence seizure.

    PubMed

    Hanaya, R; Hosoyama, H; Sugata, S; Tokudome, M; Hirano, H; Tokimura, H; Kurisu, K; Serikawa, T; Sasa, M; Arita, K

    2012-09-27

    The spontaneously epileptic rat (SER) is a double mutant (zi/zi, tm/tm) which begins to exhibit tonic convulsions and absence seizures after 6 weeks of age, and repetitive tonic seizures over time induce sclerosis-like changes in SER hippocampus with high brain-derived neurotrophic factor (BDNF) expression. Levetiracetam, which binds to synaptic vesicle protein 2A (SV2A), inhibited both tonic convulsions and absence seizures in SERs. We studied SER brains histologically and immunohistochemically after verification by electroencephalography (EEG), as SERs exhibit seizure-related alterations in the cerebral cortex and hippocampus. SERs did not show interictal abnormal spikes and slow waves typical of focal epilepsy or symptomatic generalized epilepsy. The difference in neuronal density of the cerebral cortex was insignificant between SER and Wistar rats, and apoptotic neurons did not appear in SERs. BDNF distributions portrayed higher values in the entorhinal and piriform cortices which would relate with hippocampal sclerosis-like changes. Similar synaptophysin expression in the cerebral cortex and hippocampus was found in both animals. Low and diffuse SV2A distribution portrayed in the cerebral cortex and hippocampus of SERs was significantly less than that of all cerebral lobes and inner molecular layer (IML) of the dentate gyrus (DG) of Wistar rats. The extent of low SV2A expression/distribution in SERs was particularly remarkable in the frontal (51% of control) and entorhinal cortices (47%). Lower synaptotagmin-1 expression (vs Wistar rats) was located in the frontal (31%), piriform (13%) and entorhinal (39%) cortices, and IML of the DG (38%) in SER. Focal low distribution of synaptotagmin-1 accompanying low SV2A expression may contribute to epileptogenesis and seizure propagation in SER.

  19. Epileptiform synchronization and high-frequency oscillations in brain slices comprising piriform and entorhinal cortices.

    PubMed

    Hamidi, S; Lévesque, M; Avoli, M

    2014-12-05

    We employed field potential recordings in extended in vitro brain slices form Sprague-Dawley rats containing the piriform and entorhinal cortices (PC and EC, respectively) to identify the characteristics of epileptiform discharges and concomitant high-frequency oscillations (HFOs, ripples: 80-200Hz, fast ripples: 250-500Hz) during bath application of 4-aminopyridine (4AP, 50μM). Ictal-like discharges occurred in PC and EC either synchronously or independently of each other; synchronous ictal discharges always emerged from a synchronous "fast" interictal background whereas asynchronous ictal discharges were preceded by a "slow" interictal event. In addition, asynchronous ictal discharges had longer duration and interval of occurrence than synchronous ictal discharges, and contained a higher proportion of ripples and fast ripples. Cutting the connections between PC and EC made synchronicity disappear and increased ictal discharges duration in the EC but failed in changing HFO occurrence in both areas. Finally, antagonizing ionotropic glutamatergic receptors abolished ictal activity in all experiments, increased the duration and rate of occurrence of interictal discharges occurring in PC-EC interconnected slices while it did not influence the slow asynchronous interictal discharges in both areas. Our results identify some novel in vitro interactions between olfactory (PC) and limbic (EC) structures that presumably contribute to in vivo ictogenesis as well.

  20. Stability analysis of micropipette aspiration of neutrophils.

    PubMed Central

    Derganc, J; Bozic, B; Svetina, S; Zeks, B

    2000-01-01

    During micropipette aspiration, neutrophil leukocytes exhibit a liquid-drop behavior, i.e., if a neutrophil is aspirated by a pressure larger than a certain threshold pressure, it flows continuously into the pipette. The point of the largest aspiration pressure at which the neutrophil can still be held in a stable equilibrium is called the critical point of aspiration. Here, we present a theoretical analysis of the equilibrium behavior and stability of a neutrophil during micropipette aspiration with the aim to rigorously characterize the critical point. We take the energy minimization approach, in which the critical point is well defined as the point of the stability breakdown. We use the basic liquid-drop model of neutrophil rheology extended by considering also the neutrophil elastic area expansivity. Our analysis predicts that the behavior at large pipette radii or small elastic area expansivity is close to the one predicted by the basic liquid-drop model, where the critical point is attained slightly before the projection length reaches the pipette radius. The effect of elastic area expansivity is qualitatively different at smaller pipette radii, where our analysis predicts that the critical point is attained at the projection lengths that may significantly exceed the pipette radius. PMID:10866944

  1. [What is the contribution of aspiration cytology?].

    PubMed

    Pluot, M

    1999-01-01

    Aspiration cytology of thyroid nodules is essentially designed to determine the benign nature of the nodule in order to avoid purely diagnosis surgery. It is reliable in the diagnosis of anaplastic papillary and medullary carcinomas and most lymphomas, but is more problematical for the diagnosis of the benign or malignant nature of Hürthle cell tumours and certain vesicular tumours, in which cytology reveals a suspicious, doubtful or undetermined appearance. However, whether they are unambiguous or doubtful, fine needle aspiration cytology results help the surgeon to define the therapeutic strategy under the best possible conditions. A therapeutic approach is proposed, based on the formulation of aspiration cytology results into benign, malignant, suspicious and inadequate.

  2. [Patient's Risk Factors for Perioperative Aspiration Pneumonia].

    PubMed

    Ishikawa, Teruhiko; Isono, Shiroh

    2016-01-01

    This article reviews patient's own risk factors for perioperative aspiration pneumonia. Maintaining the function of the lower esophageal sphincter (LES), the airway protective reflex, and the oral hygiene are the most important to prevent the pneumonia. The LES is adversely affected by excessive stomach distention, some medication given in perioperative periods, and habitual smoking, as well as pathological status such as esophageal hiatus hernia and achalasia. Postapoplectic patients may have insufficient airway protective reflex including swallowing and laryngeal reflex. It is emphasized that the perioperative oral care is increasing in its importance for the prevention of aspiration pneumonia.

  3. Entorhinal theta-frequency input to the dentate gyrus trisynaptically evokes hippocampal CA1 LTP

    PubMed Central

    Stepan, Jens; Dine, Julien; Fenzl, Thomas; Polta, Stephanie A.; von Wolff, Gregor; Wotjak, Carsten T.; Eder, Matthias

    2012-01-01

    There exists substantial evidence that some forms of explicit learning in mammals require long-term potentiation (LTP) at hippocampal CA3-CA1 synapses. While CA1 LTP has been well characterized at the monosynaptic level, it still remains unclear how the afferent systems to the hippocampus can initiate formation of this neuroplastic phenomenon. Using voltage-sensitive dye imaging (VSDI) in a mouse brain slice preparation, we show that evoked entorhinal cortical (EC) theta-frequency input to the dentate gyrus highly effectively generates waves of neuronal activity which propagate through the entire trisynaptic circuit of the hippocampus (“HTC-Waves”). This flow of activity, which we also demonstrate in vivo, critically depends on frequency facilitation of mossy fiber to CA3 synaptic transmission. The HTC-Waves are rapidly boosted by the cognitive enhancer caffeine (5 μM) and the stress hormone corticosterone (100 nM). They precisely follow the rhythm of the EC input, involve high-frequency firing (>100 Hz) of CA3 pyramidal neurons, and induce NMDA receptor-dependent CA1 LTP within a few seconds. Our study provides the first experimental evidence that synchronous theta-rhythmical spiking of EC stellate cells, as occurring during EC theta oscillations, has the capacity to drive induction of CA1 LTP via the hippocampal trisynaptic pathway. Moreover, we present data pointing to a basic filter mechanism of the hippocampus regarding EC inputs and describe a methodology to reveal alterations in the “input–output relationship” of the hippocampal trisynaptic circuit. PMID:22988432

  4. Transthoracic needle aspiration in solitary pulmonary nodule

    PubMed Central

    Yang, Wen; Jiang, Hongli; Khan, Ali Nawaz; Allen, Carolyn; Bertolaccini, Luca

    2017-01-01

    With improved awareness of public health and the recent advances in various imaging technologies, the detection rate of solitary pulmonary nodules (SPN) is continuously increasing. Transthoracic needle aspiration (TTNA) has represented a major approach for the diagnosis and differential diagnosis of pulmonary masses, owing to its simplicity and minimal invasiveness. This paper demonstrates the role of TTNA in SPN. PMID:28331827

  5. 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.

  6. Factors Influencing High School Students' Career Aspirations

    ERIC Educational Resources Information Center

    Tang, Mei; Pan, Wei; Newmeyer, Mark D.

    2008-01-01

    This article explores the factors influencing high school students' career aspirations with a study analyzing 141 high school students. The Social Cognitive Career Development Model was utilized to examine the interactive relationships among learning experiences, career self-efficacy, outcome expectations, career interests, and career choices. The…

  7. Occupational Aspirations and Expectations of Australian Adolescents

    ERIC Educational Resources Information Center

    Patton, Wendy; Creed, Peter

    2007-01-01

    Adolescents across the five years of high school (169 females and 164 males) completed a survey that identified occupational status aspirations and expectations coded into six types-- realistic, investigative, artistic, social, enterprising, or conventional--according to the RIASEC model (Holland, 1997). As the focus of the study was to explore…

  8. Aspiring Girls: Great Expectations or Impossible Dreams?

    ERIC Educational Resources Information Center

    Richards, Gill; Posnett, Carol

    2012-01-01

    This study explores girls' aspirations for their future. The context was an ex-coalmining area where concerns had been raised by the local authority about the levels of girls' achievement. The focus of the research was the views of Year 6 girls as they prepared for their transition to secondary school and Year 11 girls as they prepared for their…

  9. Female Aspirants to the Roman Catholic Priesthood.

    ERIC Educational Resources Information Center

    Celmer, Virginia; Winer, Jane L.

    1990-01-01

    Investigated Holland vocational-personality types, job satisfaction, and psychological dysfunction among 85 parish priests, 55 nonparish priests, and 235 women who aspire to, but are barred from, ordination in the Roman Catholic Church. Found women's Holland-type code was most similar to code of clergy member as assigned by Dictionary of Holland…

  10. The Gap between Aspiration and Practice

    ERIC Educational Resources Information Center

    Tuckett, Alan

    2013-01-01

    At the time of the fifth UNESCO international conference on adult education (CONFINTEA V) in Hamburg in 1997, it seemed that a resilient alliance of governments and civil society organizations had been created. This alliance would have the commitment and cooperation needed to pursue the ambitious aspirations captured in the 10 themes of the…

  11. Aspiration pneumonia in children: an iconographic essay*

    PubMed Central

    de Oliveira, Gabriel Antonio; Pessanha, Laís Bastos; Guerra, Luiz Felipe Alves; Martins, Diego Lima Nava; Rondina, Ronaldo Garcia; Silva, Jamine Ronacher Passos

    2015-01-01

    In most cases of aspiration pneumonia in children, the disease is specific to this age group. Clinical and radiological correlation is essential for the diagnosis. The present pictorial essay is aimed at showing typical images of the most common etiologies. PMID:26811557

  12. 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…

  13. 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

  14. 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.

  15. A novel function for Wnt signaling modulating neuronal firing activity and the temporal structure of spontaneous oscillation in the entorhinal-hippocampal circuit.

    PubMed

    Oliva, Carolina A; Inestrosa, Nibaldo C

    2015-07-01

    During early and late postnatal developments, the establishment of functional neuronal connectivity depends on molecules like Wnt that help the recently formed synapses to establish and consolidate their new cellular interactions. However, unlike other molecules, whether Wnt can modulate the firing properties of cells is unknown. Here, for the first time we explore the physiological effect of the canonical and non-canonical Wnt pathways on a circuit that is currently generating oscillatory activity, the entorhinal cortex-hippocampal circuit. Our results indicate that Wnt pathways have strong influence in the circuital and cellular properties depending on the Wnt protein isoforms, concentration, and type of neuronal circuit. Antibodies against canonical and non-canonical ligands, as well as WASP-1 and sFRP-2, demonstrate that constitutive release of Wnts contributes to the maintenance of the network and intrinsic properties of the circuit. Furthermore, we found that the excess of Wnt3a or the permanent intracellular activation of the pathway with BIO-6 accelerates the period of the oscillation by disrupting the oscillatory units (Up states) in short units, presumably by affecting the synaptic mechanisms that couples neurons into the oscillatory cycle, but without affecting the spike generation. Instead, low doses of Wnt5a increase the period of the oscillation in EC by incorporating new cells into the network activity, probably modifying firing activity in other places of the circuit. Moreover, we found that Wnt signaling operates under different principles in the hippocampus. Using pyrvinium pamoate, a Wnt/β-catenin dependent pathway inhibitor, we demonstrated that this pathway is essential to keep the firing activity in the circuit CA3, and in less degree of CA1 circuit. However, CA1 circuit possesses homeostatic mechanisms to up-regulate the firing activity when it has been suppressed in CA3, and to down-modulate the cellular excitability when exacerbated

  16. Risk and outcome of aspiration pneumonia in a city hospital.

    PubMed Central

    Jones, J.

    1993-01-01

    Because aspiration pneumonia contributes significantly to morbidity and mortality in hospitalized patients, this study was undertaken to identify risk factors for morbidity and mortality associated with aspiration pneumonia. Patients with a discharge diagnosis of aspiration pneumonia in 1985 and 1990 were studied. Factors associated with death from aspiration pneumonia were: altered mental status, cerebrovascular accident, endotracheal intubation, tachycardia, and hypoxemia. Fever, cough, and unilateral infiltrates on chest radiograph were associated with survival. Attention to proper positioning of comatose patients, aggressive treatment of gastroesophageal reflux, and strict attention to endotracheal tubes and tracheostomies should decrease the morbidity and mortality associated with aspiration pneumonia. PMID:8350375

  17. Ultrasonic gas alloy atomization under near-zero aspiration pressure

    NASA Astrophysics Data System (ADS)

    Yan, Pengfei; Wang, Deping; Yan, Biao

    2015-04-01

    In this paper, ultrasonic gas atomization (USGA) of Zn-Al under near-zero aspiration pressure was discussed. The protrusion length of delivery tube was modified to adjust the aspiration pressure. Under near-zero aspiration pressure, melt filming was observed by camera and more fine powders were produced. While under larger subambient aspiration pressure, melt filming was unavailable, corresponding to less fine powders. The results suggest that the position of the wake near the delivery tube can be optimized under near-zero aspiration. Less protrusion of delivery tube reduces the energy loss in gas flow deflection. Both facilitate to produce finer powders.

  18. Dysphagia, dystussia, and aspiration pneumonia in elderly people.

    PubMed

    Ebihara, Satoru; Sekiya, Hideki; Miyagi, Midori; Ebihara, Takae; Okazaki, Tatsuma

    2016-03-01

    Despite the development and wide distribution of guidelines for pneumonia, death from pneumonia is increasing due to population aging. Conventionally, aspiration pneumonia was mainly thought to be one of the infectious diseases. However, we have proven that chronic repeated aspiration of a small amount of sterile material can cause the usual type of aspiration pneumonia in mouse lung. Moreover, chronic repeated aspiration of small amounts induced chronic inflammation in both frail elderly people and mouse lung. These observations suggest the need for a paradigm shift of the treatment for pneumonia in the elderly. Since aspiration pneumonia is fundamentally based on dysphagia, we should shift the therapy for aspiration pneumonia from pathogen-oriented therapy to function-oriented therapy. Function-oriented therapy in aspiration pneumonia means therapy focusing on slowing or reversing the functional decline that occurs as part of the aging process, such as "dementia → dysphagia → dystussia → atussia → silent aspiration". Atussia is ultimate dysfunction of cough physiology, and aspiration with atussia is called silent aspiration, which leads to the development of life-threatening aspiration pneumonia. Research pursuing effective strategies to restore function in the elderly is warranted in order to decrease pneumonia deaths in elderly people.

  19. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:26902707

  1. Facial Blast Injury Resulting in Sand Aspiration

    DTIC Science & Technology

    2009-01-01

    recent case of a blast-injury survivor in Iraq with findings consistent with sand aspiration on computed tomography (CT) and review presentation...which may contain material such as calcium carbonate or aluminum silicate, produces characteristic findings on both computed tomography (CT) and...extubated. On hospital day 2, copious thick fluid described as “muddy” was suctioned from the respiratory tract, at which time a well tolerated

  2. Percutaneous gallbladder aspiration for acute cholecystitis

    PubMed Central

    Rassameehiran, Supannee; Nugent, Kenneth

    2016-01-01

    Early cholecystectomy for patients with acute cholecystitis may not be possible in some clinical settings. Percutaneous gallbladder aspiration (PGBA) offers an alternative approach, but the benefits and risks of this procedure are unclear. We synthesized data on the outcomes of PGBA in acute cholecystitis patients using data sources from online databases, including MEDLINE and EMBASE, and bibliographies of included studies from January 2000 through December 2015. Two reviewers independently reviewed and critiqued the quality of each study. Seven eligible studies met our criteria. The success rates in single PGBA and repetitive PGBA (2–4 times) were 50% to 93% and 76% to 96%, respectively. Complication rates were 0% to 8% and were unrelated to the size of needle gauge used for aspiration and the number of aspirations. Salvage percutaneous cholecystostomy (PC) and urgent surgery were required in 0% to 43% of patients and 0% to 4% of patients, respectively. Two studies with antibiotic instillation had clinical success rates of 95% and 96%. In conclusion, repetitive PGBA combined with antibiotic instillation and salvage PC are useful alternatives to early cholecystectomy in patients with acute cholecystitis. PMID:27695167

  3. 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.

  4. Dysphagia, dystussia, and aspiration pneumonia in elderly people

    PubMed Central

    Sekiya, Hideki; Miyagi, Midori; Ebihara, Takae; Okazaki, Tatsuma

    2016-01-01

    Despite the development and wide distribution of guidelines for pneumonia, death from pneumonia is increasing due to population aging. Conventionally, aspiration pneumonia was mainly thought to be one of the infectious diseases. However, we have proven that chronic repeated aspiration of a small amount of sterile material can cause the usual type of aspiration pneumonia in mouse lung. Moreover, chronic repeated aspiration of small amounts induced chronic inflammation in both frail elderly people and mouse lung. These observations suggest the need for a paradigm shift of the treatment for pneumonia in the elderly. Since aspiration pneumonia is fundamentally based on dysphagia, we should shift the therapy for aspiration pneumonia from pathogen-oriented therapy to function-oriented therapy. Function-oriented therapy in aspiration pneumonia means therapy focusing on slowing or reversing the functional decline that occurs as part of the aging process, such as “dementia → dysphagia → dystussia → atussia → silent aspiration”. Atussia is ultimate dysfunction of cough physiology, and aspiration with atussia is called silent aspiration, which leads to the development of life-threatening aspiration pneumonia. Research pursuing effective strategies to restore function in the elderly is warranted in order to decrease pneumonia deaths in elderly people. PMID:27076964

  5. Importance of diffuse aspiration bronchiolitis caused by chronic occult aspiration in the elderly.

    PubMed

    Matsuse, T; Oka, T; Kida, K; Fukuchi, Y

    1996-11-01

    Diffuse aspiration bronchiolitis (DAB) is a new term that we proposed to define a clinical entity that is characterized by a chronic inflammation of bronchioles caused by recurrent aspiration of foreign particles. In the present study, a total of 4,880 consecutive autopsies were reviewed and we found 31 patients with DAB (0.64%). To investigate the clinicopathologic features of DAB, the 23 patients with DAB (age, 81.2 +/- 6.2 years [mean +/- SD]), from whom clinical information was available, had their features compared to those of 40 randomly selected patients with aspiration pneumonia (age, 81.9 +/- 8.3 years [mean +/- SD]). Oropharyngeal dysphagia was observed in half of the patients with DAB, and two thirds of patients with DAB were bedridden. The onset of DAB was more insidious than aspiration pneumonia, and in half of the patients with DAB episodes of aspiration were unrecognized. Neurologic disorders (52.2%) and dementia (47.8%) were common associated diseases. Most patients with DAB showed signs of bronchorrhea, bronchospasm, and dyspnea. The macroscopic appearance of the cut surface of DAB lung showed diffusely scattered miliary yellowish nodules that resembled those of diffuse panbronchiolitis (DPB). Histologic findings of DAB were characterized by localization of chronic mural inflammation with foreign body reaction in bronchioles. Recurrence of small amounts of aspiration might play a role in the pathogenesis of DAB. In view of possible therapeutic intervention, we emphasized the importance of recognizing this entity and differentiating DAB from pulmonary diseases associated with bronchospasm in the elderly, in particular, late-onset asthma and DPB.

  6. When Aspirations Exceed Expectations: Quixotic Hope Increases Depression among Students

    PubMed Central

    Cruwys, Tegan

    2015-01-01

    A paradox exists in modern schooling: students are simultaneously more positive about the future and more depressed than ever. We suggest that these two phenomena may be linked. Two studies demonstrated that students are more likely to be depressed when educational aspirations exceed expectations. In Study 1 (N = 85) aspiring to a thesis grade higher than one expected predicted greater depression at the beginning and end of the academic year. In Study 2 (N = 2820) aspiring to a level of education (e.g., attending college) higher than one expected to achieve predicted greater depression cross-sectionally and five years later. In both cases the negative effects of aspiring high while expecting low persisted even after controlling for whether or not students achieved their educational aspirations. These findings highlight the danger of teaching students to aspire higher without also investing time and money to ensure that students can reasonably expect to achieve their educational goals. PMID:26352151

  7. The use of oxytocin in nipple fluid aspiration.

    PubMed

    Zhang, Liping; Shao, Zhi-Ming; Beatty, Perrin; Sartippour, Maryam; Wang, He-Jing; Elashoff, Robert; Chang, Helena; Brooks, Mai N

    2003-01-01

    It has been shown that early detection of breast cancer saves lives. Recently there has been increasing interest in nipple aspirate fluid as a potential avenue for breast cancer diagnosis. One major challenge regarding studies of nipple aspirate fluid is the ability to obtain adequate samples. Here we describe the use of nasal oxytocin in a group of volunteer women in order to increase the yield of nipple aspirate fluid.

  8. Efferent connections of the orbitofrontal cortex in the marmoset (Saguinus oedipus).

    PubMed

    Leichnetz, G R; Astruc, J

    1975-02-07

    Unilateral partial ablations were made in the orbitofrontal cortex of 4 adult marmosets (Saguinus oedipus) and fiber degeneration was traced using the Nauta-Gygax and Fink-Heimer selective silver impregnation techniques. Corticocortical projections were found to the ipsilateral convexity and medial aspect of the frontal lobe and to the homologous orbitofrontal areas of the contralateral hemisphere. Fiber degeneration was followed through the uncinate fascicle to the temporal and insular cortices, and caudally into the rostrolateral entorhinal cortex. Other fibers joined the cingulum bundle and terminated throughout the cingulate cortex. Subcortical projections were observed to the lateral and basal amygdaloid nuclei, caudate head, ventrolateral putamen and ventral claustrum. The lateral preoptic and hypothalamic areas received a small number of fibers, as did the intralaminar and reticular thalamic nuclei. The dorsomedial nucleus of the thalamus was recipient of a large group of fibers which followed the ventral internal capsule and joined the inferior thalamic peduncle to terminate there. Preterminal debris appeared heaviest in the dorsomedial thalamic nucleus, pars magnocellularis (MDmc) in more caudal orbital lesions. A subthalamic projection to field H of Forel was observed. A small number of fibers terminated in the lateral midbrain tegmentum, but no appreciable fiber degeneration was observed more caudally than the midbrain. These results are compared in some areas to findings in the rhesus monkey. The possibility of a topical organization in the orbital cortical and thalamic projections is discussed.

  9. [An Overview of Incidence and Outcome of Perioperative Pulmonary Aspiration].

    PubMed

    Nakazawa, Koichi; Shinoda, Ken

    2016-01-01

    Examination of the literature suggests that the incidence of aspiration pneumonia in the perioperative period is relatively infrequent. Since Mendelson's report of aspiration pneumonitis in 1946, the factors that contribute to the likelihood of aspiration have been identified, and numerous attempts for preventions for regurgitation or pulmonary aspiration have been made. The low incidence of major morbidity of anesthesia-related pulmonary aspiration may be due to adopting quality measures, applying practice guidelines for preoperative fasting, and the use of pharmacologic agents to reduce the risk of pulmonary aspiration. More systematic preoperative checking and more careful selection of patients are necessary when a supraglottic airway is used in preference to a tracheal tube. Second generation supraglottic airways may not reduce the risk of regurgitation, but may reduce the chance of aspiration if the mask position is correct and drain tube works well. Because the mortality and morbidity of aspiration pneumonia remain relatively high, the preoperative risk evaluation is very important to avoid regurgitation or aspiration.

  10. Effects of aspiration on fundamental frequency in Taiwanese syllables

    NASA Astrophysics Data System (ADS)

    Lai, Yuwen; Jongman, Allard

    2005-04-01

    The perturbation effect on vowel fundamental frequency (F0) by voiceless aspirated and unaspirated prevocalic obstruents is investigated in Taiwanese. It is well known that F0 is significantly higher after voiceless than voiced stops. However, the perturbation effect caused by aspiration has received much less attention. Twenty-eight minimal pairs contrasting in prevocalic aspiration across three different places of articulation from seven tonal categories in Taiwanese were recorded from two male and two female speakers. An acoustic study was conducted on a total of 1120 syllables. Onset, offset, and mean F0 as well as contours of the tones after the aspirated and unaspirated obstruents were compared. Results indicate that the onset and mean F0 are significantly higher when following aspirated obstruents but no difference was found in offset F0. Tonal contour comparison shows that the F0 raising effect triggered by aspirated obstruents disappears at 50-60% of the tone. Higher larynx and faster airflow rate are posited as the major factors for the higher F0 after voiceless aspirated obstruents. The present results warrant a reconsideration of the traditional theory of aspiration-induced tonal split according to which a tonal split resulted from the lowering of F0 due to aspiration.

  11. Silent aspiration detection by breath and swallowing sound analysis.

    PubMed

    Sarraf Shirazi, Samaneh; Moussavi, Zahra

    2012-01-01

    Detecting aspiration after swallows (the entry of bolus into trachea) is often a difficult task particularly when the patient does not cough; those are called silent aspiration. In this study, the application of acoustical analysis in detecting silent aspiration is investigated. We recorded the swallowing and the breath sounds of 10 individuals with swallowing disorders, who demonstrated silent aspiration during the fiberoptic endoscopic evaluation of swallowing (FEES) assessment. We analyzed the power spectral density (PSD) of the breath sound signals following each swallow; the PSD showed higher magnitude at low frequencies for the breath sounds following an aspiration. Therefore, we divided the frequency range below 300 Hz into 3 sub-bands, over which we calculated the average power as the characteristic features for the classification purpose. Then, the fuzzy k-means unsupervised classification method was deployed to find the two clusters in the data set: the aspirated and non-aspirated groups. The results were evaluated using the FEES assessments provided by the speech language pathologists. The results show 82.3% accuracy in detecting swallows with silent aspiration. Although the proposed method should be verified on a larger dataset, the results are promising for the use of acoustical analysis as a clinical tool to detect silent aspiration.

  12. 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)

  13. Perirhinal Cortex Hyperexcitability in Pilocarpine-Treated Epileptic Rats

    PubMed Central

    Benini, Ruba; Longo, Daniela; Biagini, Giuseppe; Avoli, Massimo

    2016-01-01

    The perirhinal cortex (PC), which is heavily connected with several epileptogenic regions of the limbic system such as the entorhinal cortex and amygdala, is involved in the generation and spread of seizures. However, the functional alterations occurring within an epileptic PC network are unknown. Here, we analyzed this issue by using in vitro electrophysiology and immunohistochemistry in brain tissue obtained from pilocarpine-treated epileptic rats and age-matched, nonepileptic controls (NECs). Neurons recorded intracellularly from the PC deep layers in the two experimental groups had similar intrinsic and firing properties and generated spontaneous depolarizing and hyperpolarizing postsynaptic potentials with comparable duration and amplitude. However, spontaneous and stimulus-induced epileptiform discharges were seen with field potential recordings in over one-fifth of pilocarpine-treated slices but never in NEC tissue. These network events were reduced in duration by antagonizing NMDA receptors and abolished by NMDA + non-NMDA glutamatergic receptor antagonists. Pharmacologically isolated isolated inhibitory postsynaptic potentials had reversal potentials for the early GABAA receptor-mediated component that were significantly more depolarized in pilocarpine-treated cells. Experiments with a potassium-chloride cotransporter 2 antibody identified, in pilocarpine-treated PC, a significant immunostaining decrease that could not be explained by neuronal loss. However, interneurons expressing parvalbumin and neuropeptide Y were found to be decreased throughout the PC, whereas cholecystokinin-positive cells were diminished in superficial layers. These findings demonstrate synaptic hyper-excitability that is contributed by attenuated inhibition in the PC of pilocarpine-treated epileptic rats and underscore the role of PC networks in temporal lobe epilepsy. PMID:20865722

  14. Osteogenic potential of reamer irrigator aspirator (RIA) aspirate collected from patients undergoing hip arthroplasty.

    PubMed

    Porter, Ryan M; Liu, Fangjun; Pilapil, Carmencita; Betz, Oliver B; Vrahas, Mark S; Harris, Mitchel B; Evans, Christopher H

    2009-01-01

    Intramedullary nailing preceded by canal reaming is the current standard of treatment for long-bone fractures requiring stabilization. However, conventional reaming methods can elevate intramedullary temperature and pressure, potentially resulting in necrotic bone, systemic embolism, and pulmonary complications. To address this problem, a reamer irrigator aspirator (RIA) has been developed that combines irrigation and suction for reduced-pressure reaming with temperature modulation. Osseous particles aspirated by the RIA can be recovered by filtration for use as an autograft, but the flow-through is typically discarded. The purpose of this study was to assess whether this discarded filtrate has osteogenic properties that could be used to enhance the total repair potential of aspirate. RIA aspirate was collected from five patients (ages 71-78) undergoing hip hemiarthroplasty. Osseous particles were removed using an open-pore filter, and the resulting filtrate (230 +/- 200 mL) was processed by Ficoll-gradient centrifugation to isolate mononuclear cells (6.2 +/- 5.2 x 10(6) cells/mL). The aqueous supernatant contained FGF-2, IGF-I, and latent TGF-beta1, but BMP-2 was below the limit of detection. The cell fraction included culture plastic-adherent, fibroblastic cells that displayed a surface marker profile indicative of mesenchymal stem cells and that could be induced along the osteogenic, adipogenic, and chondrogenic lineages in vitro. When compared to outgrowth cells from the culture of osseous particles, filtrate cells were more sensitive to seeding density during osteogenic culture but had similar capacity for chondrogenesis. These results suggest using RIA aspirate to develop improved, clinically expeditious, cost-effective technologies for accelerating the healing of bone and other musculoskeletal tissues.

  15. Osteogenic Potential of Reamer Irrigator Aspirator (RIA) Aspirate Collected from Patients Undergoing Hip Arthroplasty

    PubMed Central

    Porter, Ryan M.; Liu, Fangjun; Pilapil, Carmencita; Betz, Oliver B.; Vrahas, Mark S.; Harris, Mitchel B.; Evans, Christopher H.

    2009-01-01

    Intramedullary nailing preceded by canal reaming is the current standard of treatment for long-bone fractures requiring stabilization. However, conventional reaming methods can elevate intramedullary temperature and pressure, potentially resulting in necrotic bone, systemic embolism, and pulmonary complications. To address this problem, a reamer irrigator aspirator (RIA) has been developed that combines irrigation and suction for reduced-pressure reaming with temperature modulation. Osseous particles aspirated by the RIA can be recovered by filtration for use as an autograft, but the flow-through is typically discarded. The purpose of this study was to assess whether this discarded filtrate has osteogenic properties that could be used to enhance the total repair potential of aspirate. RIA aspirate was collected from five patients (ages 71–78) undergoing hip hemiarthroplasty. Osseous particles were removed using an open-pore filter, and the resulting filtrate (230 ± 200 mL) was processed by Ficoll-gradient centrifugation to isolate mononuclear cells (6.2 ± 5.2 × 106 cells/mL). The aqueous supernatant contained FGF-2, IGF-I, and latent TGF-β1, but BMP-2 was below the limit of detection. The cell fraction included culture plastic-adherent, fibroblastic cells that displayed a surface marker profile indicative of mesenchymal stem cells and that could be induced along the osteogenic, adipogenic, and chondrogenic lineages in vitro. When compared to outgrowth cells from the culture of osseous particles, filtrate cells were more sensitive to seeding density during osteogenic culture but had similar capacity for chondrogenesis. These results suggest using RIA aspirate to develop improved, clinically expeditious, cost-effective technologies for accelerating the healing of bone and other musculoskeletal tissues. PMID:18655129

  16. Emergent intrathecal baclofen withdrawal after pseudomeningocele aspiration.

    PubMed

    Smith, Timothy R; Mithal, Divakar S; Park, Anne; Bohnen, Angela; Adel, Joseph; Rosenow, Joshua M

    2013-01-01

    Intrathecal baclofen (ITB) infusion has become a common treatment for severe spasticity. Many complications of these drug delivery systems have been reported such as those related to improper dosing, mechanical failure of the implanted pump or catheter, or post-operative wound issues. We report a case of ITB withdrawal after pseudomeningocele aspiration. A 21 year-old male with spastic quadriparesis due to traumatic brian injury (TBI) presented with a pseudomeningocele surrounding an ITB pump (215 mcg/day, continuous) implanted in the abdomen. The pseudomeningocele was percutaneously aspirated and approximately 15 hours later the patient developed signs and symptoms of acute baclofen withdrawal. As a result, the patient underwent an exploration of the ITB infusion system with an intraoperative epidural blood patch. The symptoms of ITB withdrawal improved over the next 18 hours. The subcutaneous cerebrospinal fluid (CSF) collection partially recurred 48 hours later, but this resolved after a second epidural blood patch. The case illustrates a unique presentation of a serious complication of ITB infusion. This underscores that timely diagnosis and treatment of acute baclofen withdrawal is key to optimal outcomes.

  17. Young APOE[subscript 4] Targeted Replacement Mice Exhibit Poor Spatial Learning and Memory, with Reduced Dendritic Spine Density in the Medial Entorhinal Cortex

    ERIC Educational Resources Information Center

    Rodriguez, Gustavo A.; Burns, Mark P.; Weeber, Edwin J.; Rebeck, G. William

    2013-01-01

    The apolipoprotein E4 ("APOE-[epsilon]4") allele is the strongest genetic risk factor for developing late-onset Alzheimer's disease, and may predispose individuals to Alzheimer's-related cognitive decline by affecting normal brain function early in life. To investigate the impact of human APOE alleles on cognitive performance in mice, we trained…

  18. Respective Role of the Dorsal Hippocampus and the Entorhinal Cortex during the Recombination of Previously Learned Olfactory-Tactile Associations in the Rat

    ERIC Educational Resources Information Center

    Boisselier, Lise; Ferry, Barbara; Gervais, Rémi

    2017-01-01

    The hippocampal formation has been extensively described as a key component for object recognition in conjunction with place and context. The present study aimed at describing neural mechanisms in the hippocampal formation that support olfactory-tactile (OT) object discrimination in a task where space and context were not taken into account. The…

  19. Interneurons, tau and amyloid-β in the piriform cortex in Alzheimer's disease.

    PubMed

    Saiz-Sanchez, Daniel; De la Rosa-Prieto, Carlos; Ubeda-Banon, Isabel; Martinez-Marcos, Alino

    2015-07-01

    Impaired olfaction has been described as an early symptom of Alzheimer's disease. Neuroanatomical changes underlying this deficit in the olfactory system are largely unknown. Interestingly, neuropathology begins in the transentorhinal cortex and extends to the neighboring limbic system and basal telencephalic structures that mediate olfactory processing, including the anterior olfactory nucleus and olfactory bulb. The human piriform cortex has been described as a crucial area in odor quality coding; disruption of this region mediates early olfactory deficits in Alzheimer's disease. Most neuropathological investigations have focused on the entorhinal cortex and hippocampus, whereas the piriform cortex has largely been neglected. This work aims to characterize the expression of the neuropathological amyloid-β peptide, tau protein and interneuron population markers (calretinin, parvalbumin and somatostatin) in the piriform cortex of ten Alzheimer-diagnosed (80.4 ± 8.3 years old) and five control (69.6 ± 11.1) cases. Here, we examined the distribution of different interneuronal markers as well as co-localization of interneurons and pathological markers. Results indicated preferential vulnerability of somatostatin- (p = 0.0001 < α = 0.05) and calretinin-positive (p = 0.013 < α = 0.05) cells that colocalized with amyloid-β peptide, while the prevalence of parvalbumin-positive cells was increased (p = 0.045 < α = 0.05) in the Alzheimer's cases. These data may help to reveal the neural basis of olfactory deficits linked to Alzheimer's disease as well as to characterize neuronal populations preferentially vulnerable to neuropathology in regions critically involved in early stages of the disease.

  20. Optogenetic Stimulation of Lateral Amygdala Input to Posterior Piriform Cortex Modulates Single-Unit and Ensemble Odor Processing.

    PubMed

    Sadrian, Benjamin; Wilson, Donald A

    2015-01-01

    Olfactory information is synthesized within the olfactory cortex to provide not only an odor percept, but also a contextual significance that supports appropriate behavioral response to specific odor cues. The piriform cortex serves as a communication hub within this circuit by sharing reciprocal connectivity with higher processing regions, such as the lateral entorhinal cortex and amygdala. The functional significance of these descending inputs on piriform cortical processing of odorants is currently not well understood. We have employed optogenetic methods to selectively stimulate lateral and basolateral amygdala (BLA) afferent fibers innervating the posterior piriform cortex (pPCX) to quantify BLA modulation of pPCX odor-evoked activity. Single unit odor-evoked activity of anesthetized BLA-infected animals was significantly modulated compared with control animal recordings, with individual cells displaying either enhancement or suppression of odor-driven spiking. In addition, BLA activation induced a decorrelation of odor-evoked pPCX ensemble activity relative to odor alone. Together these results indicate a modulatory role in pPCX odor processing for the BLA complex. This interaction could contribute to learned changes in PCX activity following associative conditioning, as well as support alternate patterns of odor processing that are state-dependent.

  1. 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…

  2. Factors Related to Postgraduate Educational Aspirations of Women College Graduates.

    ERIC Educational Resources Information Center

    de Wolf, Virginia A.

    This study compared 105 women university baccalaureates intending graduate study the year following graduation with women graduates matched by age and major who did not intend such study. Aspirers had significantly higher GPAs than non-aspirers, were more satisfied with their undergraduate major, had more often selected their major as preparation…

  3. 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…

  4. 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...

  5. 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...

  6. A new portable aspirator for culicidae and other winged insects.

    PubMed

    Governatori, M; Bulgarini, C; Rivasi, F; Pampiglione, S

    1993-12-01

    A new type of portable aspirator is described. The aspirator uses as a suction device a fan that normally cools computers, in conjunction with other structural elements especially designed to cope with the greater suction power available. The device proved to be efficient, strong, light, easy to use, and silent.

  7. Career Aspirations of Women in the 20th Century

    ERIC Educational Resources Information Center

    Domenico, Desirae M.; Jones, Karen H.

    2006-01-01

    Women have increasingly become more involved in the workforce following World War II. Paid employment of women has shifted from primarily traditional female-oriented jobs to more non-traditional, and previously male-oriented careers. Women's participation in the workforce has lead to the study of career aspirations of women. Career aspirations are…

  8. A tale of three aspirations: foreign bodies in the airway.

    PubMed

    Pritt, B; Harmon, M; Schwartz, M; Cooper, K

    2003-10-01

    Tracheobronchial foreign body aspiration is a serious medical problem, with clinical manifestations ranging from acute asphyxiation to insidious lung damage, as demonstrated by the three presented cases. Patient 1 aspirated during dinner, emergency bronchoscopy retrieved pieces of food, and she fully recovered the following day. Patient 2 presented with recurrent pneumonia and a right lower lobe lung abscess. After right lower lobectomy, pathology revealed a foreign object in the right main stem bronchus, a peanut aspirated one year earlier. Patient 3 became unresponsive several days after spinal surgery. The differential diagnosis included myocardial infarction, stroke, and foreign body aspiration. The patient died and necropsy revealed a foreign body in the right main stem bronchus (cooked meat). Thus, foreign body aspiration is not always suspected clinically, and the pathologist may play an important role in making the diagnosis. Histological identification of the aspirated material may be necessary for definitive diagnosis. Therefore, sections of commonly aspirated foods are presented, together with a 10 year history of aspirated objects received by this institution's surgical pathology department.

  9. 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…

  10. An Analysis of Taiwanese Aboriginal Students' Educational Aspirations

    ERIC Educational Resources Information Center

    Hou, Hsiao-I; Huang, Chia-Kai

    2012-01-01

    By analysing the national data from the Junior Survey of the Taiwan Higher Education Dataset, this study identified significant variables influencing the educational aspirations of aboriginal students at technical and vocational institutions. The study shows that several variables are predictive of the educational aspirations of aboriginal…

  11. Study of Educational Aspirations of Preparatory School Students in Yemen.

    ERIC Educational Resources Information Center

    Edington, Everett D.

    To identify causes for low enrollment in secondary agricultural schools in Yemen, the United States Agency for International Development and the Yemen Ministry of Education surveyed 990 preparatory (junior high) students, examining their educational aspirations, differences between rural and urban youth, major influences on student aspirations,…

  12. The Aspiration-Attainment Gap: Black Students and Education

    ERIC Educational Resources Information Center

    Buttaro, Anthony, Jr.; Battle, Juan; Pastrana, Antonio, Jr.

    2010-01-01

    Using a nationally representative sample from two waves of the National Educational Longitudinal Study (NELS), this research examines the aspiration-attainment gap that exists for Black students (N = 823). This gap is a measure of the difference between the educational level students said they aspired to reach reported in 1988 when attending 8th…

  13. Stability of Career Aspirations: A Longitudinal Test of Gottfredson's Theory

    ERIC Educational Resources Information Center

    Junk, Kate E.; Armstrong, Patrick Ian

    2010-01-01

    Gottfredson's theory of the career compromise process was evaluated using a longitudinal data set of 2,353 female and 321 male students recruited for Zuckerman's "Seven College Study," who reported their career aspirations twice over a 1-year period. Expressed career aspirations were coded on the dimensions of sex type, prestige, and the…

  14. 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.

  15. 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…

  16. 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…

  17. Mortality, morbidity, and disease severity of patients with aspiration pneumonia

    PubMed Central

    Lanspa, Michael J.; Jones, Barbara E.; Brown, Samuel M.; Dean, Nathan C.

    2013-01-01

    Background Aspiration pneumonia is a common syndrome, although less well characterized than other pneumonia syndromes. We describe a large population of patients with aspiration pneumonia. Methods In this retrospective population study, we queried the electronic medical record at a tertiary-care, university-affiliated hospital from 1996–2006. Patients were initially identified by ICD-9 code 507.x; subsequent physician chart review excluded patients with aspiration pneumonitis and those without a confirmatory radiograph. Patients with community-acquired aspiration pneumonia were compared to a contemporaneous population of community-acquired pneumonia (CAP) patients. We compared CURB-65 predicted mortality with actual 30-day mortality. Results We identified 628 patients with aspiration pneumonia, of which 510 were community-acquired. Median age was 77, with 30-day mortality of 21%. Compared to CAP patients, patients with community-acquired aspiration pneumonia had more frequent inpatient admission (99% vs. 58%) and ICU admission (38% vs. 14%), higher Charlson comorbidity index (3 vs. 1), and higher prevalence of “do not resuscitate/intubate” orders (24% vs. 11%). CURB-65 predicted mortality poorly in aspiration pneumonia patients (AUC 0.66). Conclusions Patients with community-acquired aspiration pneumonia are older, have more comorbidities, and demonstrate higher mortality than CAP patients, even after adjustment for age and comorbidities. CURB-65 poorly predicts mortality in this population. PMID:23184866

  18. Calculating Student Aspiration: Bourdieu, Spatiality and the Politics of Recognition

    ERIC Educational Resources Information Center

    Gale, Trevor; Parker, Stephen

    2015-01-01

    This paper reports on a recent study of aspirations for higher education by secondary school students from disadvantaged backgrounds in regional Australia. At the same time, it goes in search of explanations that transcend a Bourdieuian account of aspirations as produced by and reproductive of cultural histories and dominance, given the apparent…

  19. Students' School Motivation and Aspiration over High School Years

    ERIC Educational Resources Information Center

    Yeung, Alexander Seeshing; McInerney, Dennis M.

    2005-01-01

    Students from a school in Hong Kong (n = 199) responded to 22 items asking about their school motivation and aspirations in a survey. Structural equation models found four school motivation factors consistent with the task, effort, competition, and praise scales of the Inventory of School Motivation, one education aspiration factor, one career…

  20. Molecular signalling pathways in the cerebral cortex are required for retrieval of one-trial avoidance learning in rats.

    PubMed

    Barros, D M; Izquierdo, L A; Mello e Souza, T; Ardenghi, P G; Pereira, P; Medina, J H; Izquierdo, I

    2000-09-01

    Rats were implanted bilaterally with cannulae in the CA1 region of the dorsal hippocampus, the entorhinal cortex, anterior cingulate cortex, posterior parietal cortex, or the basolateral complex of the amygdala. The animals were trained in one-trial step-down inhibitory avoidance and tested 24 h later. Prior (10 min) to the retention test, through the cannulae, they received 0.5 microl infusions of a vehicle (2% dimethylsulfoxide in saline), or of the following drugs dissolved in the vehicle: the glutamate NMDA receptor blocker, aminophosphonopentanoic acid (AP5, 2.0 or 5.0 microg), the AMPA receptor blocker, 6,7-dinitroquinoxaline-2,3 (1H,4H)dione (DNQX, 0.4 or 1.0 microg), the metabotropic receptor antagonist, methylcarboxyphenylglycine (MCPG, 0.5 or 2.5 microg), the inhibitor of cAMP-dependent protein kinase (PKA), Rp-cAMPs (0.1 or 0.5 microg), the PKA stimulant, Sp-cAMPs (0.5 microg), or the inhibitor of the mitogen-activated protein kinase (MAPK), PD098059 (10 or 50 microM). All these drugs, at the same doses, had been previously found to alter long-term memory formation of this task. Here, retrieval test performance was blocked by DNQX, MCPG, Rp-cAMPs and PD098059 and enhanced by Sp-cAMPs infused into CA1 or the entorhinal cortex. The drugs had similar effects when infused into the parietal or anterior cingulate cortex, except that in these two areas AP5 also blocked retrieval, and in the cingulate cortex DNQX had no effect. Infusions into the basolateral amygdala were ineffective except for DNQX, which hindered retrieval. None of the treatments that affected retrieval had any influence on performance in an open field or in a plus maze; therefore, their effect on retention testing can not be attributed to an influence on locomotion, exploration or anxiety. The results indicate that the four cortical regions studied participate actively in, and are necessary for, retrieval of the one-trial avoidance task. They require metabotropic and/or NMDA glutamate

  1. 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.

  2. Transrectal fine needle aspiration cytology of granulomatous prostatitis.

    PubMed

    Mondal, A; Mukherjee, B; Ghosh, E

    1994-07-01

    Transrectal fine needle aspiration cytology by Franzen technique was carried out from January, 1985 till January, 1992 on 567 patients having prostatomegaly which were suspicious of malignancy by clinical per rectal examination. Granulomatous prostatitis was diagnosed in 56 cases. Analysis showed 34 cases were tuberculous prostatitis and 22 cases were nonspecific granulomatous prostatitis. Comparison of aspiration cytology with bacteriological study of the aspirated material and histopathology showed correct diagnosis of granulomatous prostatitis by fine needle aspiration. The findings indicate that transrectal fine needle aspiration cytology is a reliable procedure for diagnosis of granulomatous prostatitis which can clinically mimic prostatic malignancy when it presents as a diffuse or nodular enlargement with firm to hard consistency.

  3. Acid aspiration-induced airways hyperresponsiveness in mice

    PubMed Central

    Leclair, Timothy R.; von Reyn, Jessica; Larrabee, Yuna C.; Cloutier, Mary E.; Irvin, Charles G.; Bates, Jason H. T.

    2009-01-01

    The role of gastroesophageal reflux and micro-aspiration as a trigger of airways hyperresponsiveness (AHR) in patients with asthma is controversial. The role of acid reflux and aspiration as a direct cause of AHR in normal subjects is also unclear. We speculated that aspiration of a weak acid with a pH (1.8) equivalent to the upper range of typical gastric contents would lead to AHR in naive mice. We further speculated that modest reductions in aspirate acidity to a level expected during gastric acid suppression therapy (pH 4.0) would impede aspiration-induced AHR. BALB/c female mice were briefly anesthetized with isoflurane and allowed to aspirate 75 μl of saline with HCl (pH 1.8, 4.0, or 7.4) or underwent sham aspiration. Mice were re-anesthetized 2 or 24 h later, underwent tracheostomy, and were coupled to a mechanical ventilator. Forced oscillations were used to periodically measure respiratory impedance (Zrs) following aerosol delivery of saline and increasing doses of methacholine to measure for AHR. Values for elastance (H), airways resistance (RN), and tissue damping (G) were derived from Zrs. Aspirate pH of 1.8 led to a significant overall increase in peak RN, G, and H compared with pH 4.0 and 7.4 at 2 and 24 h. Differences between pH 7.4 and 4.0 were not significant. In mice aspirating pH 1.8 compared with controls, airway lavage fluid contained more neutrophils, higher protein, and demonstrated higher permeability. We conclude that acid aspiration triggers an acute AHR, driven principally by breakdown of epithelial barrier integrity within the airways. PMID:19797689

  4. Fine needle aspiration cytology in fibromatosis

    PubMed Central

    Tanwar, Pranay; Gupta, Nalini; Vasishta, Rakesh Kumar; Singh, Gurpreet

    2012-01-01

    Fibromatosis form a spectrum of clinicopathologic entities characterized by the infiltrative proliferation of fibroblasts that lack malignant cytologic features. The fibromatosis can be localized or infiltrative and multicentric and can involve internal tissues and organs as the mesentery, retroperitoneum, breast, and almost every organ and region of the body, including the bones, the meninges and the central nervous system. We report a case of 37-year-old male who presented with a right supraclavicular mass with superficial infiltrative type of fibromatosis and fine needle aspiration cytology (FNAC) was performed. We report this case because of limited literature of FNAC in fibromatosis and quick role of FNAC in the diagnosis of fibromatosis. PMID:22438623

  5. [Our experiences with early vacuum aspiration (miniinterruption)].

    PubMed

    Poradovský, K; Ondás, P; Posluch, J

    1982-07-01

    The authors report their experiences with 80 early vacuum aspirations (mini-interruptions) performed at the 1st Dept. of Gynecology and Obstetrics of the University Hospital in Kosice during 1980-81. The procedure was performed between days 36-42 in 15% of the women, between days 43-49 in 52.7% of the women, between days 50-56 in 27.5%, and between days 57-60 in 5% of the women. Interruption of pregnancy did not require general anesthesia or hospitalization of the patients. Complications occurred in 10% of the women, 6.25% due to residua and 2.5% to inflammation. Further experience should reduce the occurrence of complications. The authors consider the method to be advantageous and prospective. (author's modified)

  6. Religiosity and Migration Aspirations among Mexican Youth.

    PubMed

    Hoffman, Steven; Marsiglia, Flavio Francisco; Ayers, Stephanie L

    2015-02-01

    International migration has become an important topic of discussion from a policy and humanitarian perspective. Part of the debate includes a renewed interest in understanding the factors that influence decisions about migration to the US among Mexican youth still residing in their country of origin. The purpose of this study was to advance knowledge specifically about internal and external religiosity and their influence on youths' migration aspirations. The data for this study were collected in 2007 from students enrolled in an alternative high school program located in the state of Guanajuato, Mexico. The findings indicated that as external religiosity increases, the desire to work or live in the USA decreases. Furthermore, as internal religiosity increases, the desire to work or live in the USA and plans to migrate increase. The results are interpreted and discussed in light of previous research on religious and cultural norm adherence.

  7. Complications of oropharyngeal dysphagia: aspiration pneumonia.

    PubMed

    Almirall, Jordi; Cabré, Mateu; Clavé, Pere

    2012-01-01

    The incidence and prevalence of aspiration pneumonia (AP) are poorly defined. They increase in direct relation with age and underlying diseases. The pathogenesis of AP presumes the contribution of risk factors that alter swallowing function and predispose to the oropharyngeal bacterial colonization. The microbial etiology of AP involves Staphylococcus aureus, Haemophilus influenzae and Streptococcus pneumoniae for community-acquired AP and Gram-negative aerobic bacilli in nosocomial pneumonia. It is worth bearing in mind the relative unimportance of anaerobic bacteria in AP. When we choose the empirical antibiotic treatment, we have to consider some pathogens identified in oropharyngeal flora. Empirical treatment with antianaerobics should only be used in certain patients. According to some known risks factors, the prevention of AP should include measures in order to avoid it.

  8. Religiosity and Migration Aspirations among Mexican Youth

    PubMed Central

    Marsiglia, Flavio Francisco; Ayers, Stephanie L.

    2014-01-01

    International migration has become an important topic of discussion from a policy and humanitarian perspective. Part of the debate includes a renewed interest in understanding the factors that influence decisions about migration to the US among Mexican youth still residing in their country of origin. The purpose of this study was to advance knowledge specifically about internal and external religiosity and their influence on youths' migration aspirations. The data for this study were collected in 2007 from students enrolled in an alternative high school program located in the state of Guanajuato, Mexico. The findings indicated that as external religiosity increases, the desire to work or live in the USA decreases. Furthermore, as internal religiosity increases, the desire to work or live in the USA and plans to migrate increase. The results are interpreted and discussed in light of previous research on religious and cultural norm adherence. PMID:25663825

  9. [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.

  10. Sialorrhea and aspiration pneumonia: a case study.

    PubMed

    Trigoboff, Eileen; Grace, Jeffery; Szymanski, Herman; Bhullar, Jaspinder; Lee, Claudia; Watson, Thomas

    2013-05-01

    This case study compares two different clinical outcomes for a patient with a long-standing psychotic disorder prescribed clozapine on two occasions. During the first trial, clozapine was used at a higher dose for this patient (350-450mg/day) and included clinically significant sialorrhea, pneumonia, and pneumonia-like illnesses requiring immediate medical intervention including hospitalization. There were also patient complaints of fatigue, cough, choking, and constipation leading to poor adherence. Clozapine was discontinued when the patient withdrew his consent due to side effects, despite his awareness of its benefits, including reduction of command hallucinations and irritability. The second clozapine trial was associated with lower daily doses and therapeutic serum blood levels. The patient was actively participating in and adhering to the medication plan. A very narrow window of clozapine dose was exceeded for two days and the patient complained of hypersalivation, cough, and lethargy. He was subsequently hospitalized for a two week period to treat aspiration pneumonia. This hospitalization helped establish the ideal daily dose of clozapine for this patient and also brought the relationship between aspiration pneumonia and clozapine to the attention of the psychiatrist and medical specialist. Once the appropriate dosage for this patient was established, his psychotic and affective symptoms were controlled, he was not hampered by adverse side effects, and he started to actively participate in social and recreational activities and plans that culminated in discharge from a state psychiatric facility to a supportive community residence. It is our hope that the lessons we have learned from our shared experience with this patient will be of benefit to other clinicians and patients.

  11. Sialorrhea and Aspiration Pneumonia: A Case Study

    PubMed Central

    Grace, Jeffery; Szymanski, Herman; Bhullar, Jaspinder; Lee, Claudia; Watson, Thomas

    2013-01-01

    This case study compares two different clinical outcomes for a patient with a long-standing psychotic disorder prescribed clozapine on two occasions. During the first trial, clozapine was used at a higher dose for this patient (350-450mg/day) and included clinically significant sialorrhea, pneumonia, and pneumonia-like illnesses requiring immediate medical intervention including hospitalization. There were also patient complaints of fatigue, cough, choking, and constipation leading to poor adherence. Clozapine was discontinued when the patient withdrew his consent due to side effects, despite his awareness of its benefits, including reduction of command hallucinations and irritability. The second clozapine trial was associated with lower daily doses and therapeutic serum blood levels. The patient was actively participating in and adhering to the medication plan. A very narrow window of clozapine dose was exceeded for two days and the patient complained of hypersalivation, cough, and lethargy. He was subsequently hospitalized for a two week period to treat aspiration pneumonia. This hospitalization helped establish the ideal daily dose of clozapine for this patient and also brought the relationship between aspiration pneumonia and clozapine to the attention of the psychiatrist and medical specialist. Once the appropriate dosage for this patient was established, his psychotic and affective symptoms were controlled, he was not hampered by adverse side effects, and he started to actively participate in social and recreational activities and plans that culminated in discharge from a state psychiatric facility to a supportive community residence. It is our hope that the lessons we have learned from our shared experience with this patient will be of benefit to other clinicians and patients. PMID:23882437

  12. Preventing aspiration in the nursing home: the role of biofilm and data from the ICU.

    PubMed

    Drinka, Paul

    2010-01-01

    Two aspiration syndromes have been identified: Aspiration pneumonia is infectious caused by micro-aspiration of oral bacteria secondary to neurogenic dysphagia or sedation. Infectious bacteria may also be aspirated from the stomach. Aspiration pneumonitis classically follows large bolus aspiration of food, acid, or digestive enzymes and is initially noninfectious. Large bolus gastric aspiration events may have an acute/dramatic onset. This article discusses (1) prevention of recurrent aspiration events caused by 2 common motility disorders: neurogenic dysphagia and gastro esophageal reflux; (2) mechanical source control (debridement/drainage) of sites that may harbor large collections of bacteria protected from antibiotics in biofilm including dental plaque, coated tongue, and chronic sinusitis.

  13. Organization of the connections between claustrum and cortex in the mouse

    PubMed Central

    Wang, Quanxin; Ng, Lydia; Harris, Julie A.; Feng, David; Li, Yang; Royall, Josh J.; Oh, Seung Wook; Bernard, Amy; Sunkin, Susan M.; Koch, Christof

    2016-01-01

    ABSTRACT The connections between the claustrum and the cortex in mouse are systematically investigated with adeno‐associated virus (AAV), an anterograde viral tracer. We first define the boundary and the three‐dimensional structure of the claustrum based on a variety of molecular and anatomical data. From AAV injections into 42 neocortical and allocortical areas, we conclude that most cortical areas send bilateral projections to the claustrum, the majority being denser on the ipsilateral side. This includes prelimbic, infralimbic, medial, ventrolateral and lateral orbital, ventral retrosplenial, dorsal and posterior agranular insular, visceral, temporal association, dorsal and ventral auditory, ectorhinal, perirhinal, lateral entorhinal, and anteromedial, posteromedial, lateroposterior, laterointermediate, and postrhinal visual areas. In contrast, the cingulate and the secondary motor areas send denser projections to the contralateral claustrum than to the ipsilateral one. The gustatory, primary auditory, primary visual, rostrolateral visual, and medial entorhinal cortices send projections only to the ipsilateral claustrum. Primary motor, primary somatosensory and subicular areas barely send projections to either ipsi‐ or contralateral claustrum. Corticoclaustral projections are organized in a rough topographic manner, with variable projection strengths. We find that the claustrum, in turn, sends widespread projections preferentially to ipsilateral cortical areas with different projection strengths and laminar distribution patterns and to certain contralateral cortical areas. Our quantitative results show that the claustrum has strong reciprocal and bilateral connections with prefrontal and cingulate areas as well as strong reciprocal connections with the ipsilateral temporal and retrohippocampal areas, suggesting that it may play a crucial role in a variety of cognitive processes. J. Comp. Neurol. 525:1317–1346, 2017. © 2016 Wiley Periodicals, Inc. PMID

  14. [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.

  15. Neuropeptide S facilitates mice olfactory function through activation of cognate receptor-expressing neurons in the olfactory cortex.

    PubMed

    Shao, Yu-Feng; Zhao, Peng; Dong, Chao-Yu; Li, Jing; Kong, Xiang-Pan; Wang, Hai-Liang; Dai, Li-Rong; Hou, Yi-Ping

    2013-01-01

    Neuropeptide S (NPS) is a newly identified neuromodulator located in the brainstem and regulates various biological functions by selectively activating the NPS receptors (NPSR). High level expression of NPSR mRNA in the olfactory cortex suggests that NPS-NPSR system might be involved in the regulation of olfactory function. The present study was undertaken to investigate the effects of intracerebroventricular (i.c.v.) injection of NPS or co-injection of NPSR antagonist on the olfactory behaviors, food intake, and c-Fos expression in olfactory cortex in mice. In addition, dual-immunofluorescence was employed to identify NPS-induced Fos immunereactive (-ir) neurons that also bear NPSR. NPS (0.1-1 nmol) i.c.v. injection significantly reduced the latency to find the buried food, and increased olfactory differentiation of different odors and the total sniffing time spent in olfactory habituation/dishabituation tasks. NPS facilitated olfactory ability most at the dose of 0.5 nmol, which could be blocked by co-injection of 40 nmol NPSR antagonist [D-Val(5)]NPS. NPS administration dose-dependently inhibited food intake in fasted mice. Ex-vivo c-Fos and NPSR immunohistochemistry in the olfactory cortex revealed that, as compared with vehicle-treated mice, NPS markedly enhanced c-Fos expression in the anterior olfactory nucleus (AON), piriform cortex (Pir), ventral tenia tecta (VTT), the anterior cortical amygdaloid nucleus (ACo) and lateral entorhinal cortex (LEnt). The percentage of Fos-ir neurons that also express NPSR were 88.5% and 98.1% in the AON and Pir, respectively. The present findings demonstrated that NPS, via selective activation of the neurons bearing NPSR in the olfactory cortex, facilitates olfactory function in mice.

  16. CX-516 Cortex pharmaceuticals.

    PubMed

    Danysz, Wojciech

    2002-07-01

    CX-516 is one of a series of AMPA modulators under development by Cortex, in collaboration with Shire and Servier, for the potential treatment of Alzheimer's disease (AD), schizophrenia and mild cognitive impairment (MCI) [234221]. By June 2001, CX-516 was in phase II trials for both schizophrenia and attention deficit hyperactivity disorder (ADHD) [412513]. A phase II trial in fragile X syndrome and autism was expected to start in May 2002 [449861]. In October 2001, Cortex was awarded a Phase II SBIR grant of $769,818 from the National Institutes of Mental Health to investigate the therapeutic potential of AMPAkines in schizophrenia. This award was to support a phase IIb study of CX-516 as a combination therapy in schizophrenia patients concomitantly treated with olanzapine. The trial was to enroll 80 patients and employ a randomized, double-blind, placebo-controlled design in which the placebo group was to receive olanzapine plus placebo and the active group was to receive olanzapine plus CX-516 [425982]. In April 2000, Shire and Cortex signed an option agreement in which Shire was to evaluate CX-516for the treatment of ADHD. Under the terms of the agreement, Shire would undertake a double-blind, placebo-controlled evaluation of CX-516 involving ADHD patients. If the study proved effective, Shire would have the right to convert its option into an exclusive worldwide license for the AMPAkines for ADHD under a development and licensing agreement. Should Shire elect to execute this agreement, Shire would bear all future developmental costs [363618]. By February 2002, Cortex and Servier had revealed their intention to begin enrolment for an international study of an AMPAkine compound as a potential treatment for MCI in the near future. Assuming enrollment proceeded as anticipated, results were expected during the second quarter of 2003 [439301]. By May 2002, phase II trials were underway [450134]. In March 2002, Cortex was awarded extended funding under the

  17. 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

  18. Prevention of suicide: aspirations and evidence.

    PubMed Central

    Gunnell, D.; Frankel, S.

    1994-01-01

    The Health of the Nation white paper set a target for 15% reduction in overall suicide rates by the year 2000. If the targets are to be achieved interventions must be identified which are of proved effectiveness. This paper examines the evidence on the available interventions and points of access to the population at risk. No single intervention has been shown in a well conducted randomised controlled trial to reduce suicide. The greatest potential seems to arise from limiting the availability of methods. In particular it is likely that the introduction of the catalytic convertor will lead to reduced lethality of care exhausts and reductions in suicide using this method. General practitioner education programmes, the effectiveness of lithium and maintenance antidepressants, and limits on the quantity of medicines available over the counter or on prescription should all be evaluated. Particular high risk groups include people recently discharged from psychiatric hospitals and those with a history of parasuicide. Many social processes affect suicide rates and these rather than specific interventions may help or hinder the ability to realise the Health of the Nation targets. Well conducted trials are essential to distinguish complex social processes from the effects of specific interventions for suicide prevention. This review of the available evidence offers little support for the aspiration that the posited targets can be achieved on the basis of current knowledge and current policy. Images p1229-a p1233-a PMID:8080520

  19. Hollow needle cataract aspiration in antiquity.

    PubMed

    Pérez-Cambrodí, Rafael J; Ascaso, Francisco J; Diab, Fathi; Alzamora-Rodríguez, Antonio; Grzybowski, Andrzej

    2015-12-01

    The dislocation of the crystalline lens or couching technique was the predominant procedure to surgically remove cataracts until the 18th century A.D. However, in the Middle Ages, some Arab physicians tried to aspirate the opaque lens by means of a glass tube following a paracentesis. Some literary sources attributed the origins of this technique to Antyllus of Alexandria, a Greek surgeon who lived in the 2nd century A.D. in the Roman Empire. Nevertheless, this statement remains unclear and is probably the consequence of posterior interpretations or incorrect translations of the manuscripts. In recent years, the discovery of the hollow needles from Montbellet (France) and Viladamat (Spain), in archaeological settlements dated between the 1st century and 3rd century A.D., has reopened the possibility of cataract extraction as an option in the surgical management of soft cataracts in the antiquity. In any case, these findings are exceptional, and thus, probably this technique was not widely practised and very likely disparaged by the medical community.

  20. Dermal mass aspirate from a Persian cat.

    PubMed

    Zimmerman, Kurt; Feldman, Bernard; Robertson, John; Herring, Erin S; Manning, Thomas

    2003-01-01

    A 1-year-old spayed female Persian cat with alopecia and weight loss had numerous variably ulcerated dermal nodules. Cytologic examination of an aspirate of one of the nodules revealed pyogranulomatous inflammation along with septate hyphae and basophilic round bodies, 0.5-1.0 microm in diameter, surrounded by a thin clear halo (arthrospores). The cytologic diagnosis was dermatophytic pseudomycetoma. Histologically, there were dermal granulomas containing poorly staining, septate hyphae with bulbous spores embedded within abundant amorphous eosinophilic material (Splendore-Hoeppli reaction), and the histologic diagnosis was pseudomycetoma-associated chronic multifocal severe granulomatous dermatitis with lymphocytic perifolliculitis and furunculosis. Microsporum canis was cultured from the lesion. Pseudomycetomas are distinguished from fungal mycetomas, or eumycotic mycetomas, by the findings of multiple lesions, lack of a history of skin trauma, an association with dermatophytes, most commonly Microsporum canis, and, histologically, lack of true cement material and a more abundant Splendore-Hoeppli reaction in pseudomycetomas. Additionally, pseudomycetomas differ from dermatophytosis, in which lesions are restricted to epidermal structures. Persian cats have a high incidence of pseudomycetoma formation, suggesting a heritable predisposition. The prognosis is fair with systemic antifungal therapy. When examining cytologic specimens from Persian cats with single or multiple dermal nodules, especially if pyogranulomatous inflammation is present, a diagnosis of pseudomycetoma should be suspected and is warranted if arthrospores and refractile septate hyphae are present.

  1. Amniotic fluid aspiration in cases of SIDS.

    PubMed

    Fracasso, Tony; Karger, Bernd; Vennemann, Mechtild; Bajanowski, Thomas; Golla-Schindler, Ute Maria; Pfeiffer, Heidi

    2010-03-01

    The scope of this study was to evaluate the incidence and the eventual consequences of amniotic fluid aspiration (AFA) in cases of sudden infant death. Cases of sudden infant death syndrome (SIDS; n = 113: 39 females, 74 males; mean age 4.6 months) were compared to a control group of 39 cases of explained death (14 females, 25 males; mean age 5.6 months). In each case, sections of the lung stained with hematoxylin and eosin and with the immunohistochemical reaction 34BE12 specific for cytokeratins were available. The microscope slides were observed at x200 magnification and semi-quantitatively classified into four categories(-, +, ++, and +++). In both groups, rests of amniotic fluid could be observed up to the fourth month of life. The comparison between the two groups did not show any significant difference. In the SIDS group, immunohistochemical reactions with the antibodies CD68, MRP8, MRP14, 27E10, 25F9, CD3, CD20Cy, and CD45R0 were available for the lungs. Twelve cases with AFA were compared to a group of SIDS cases without AFA with similar age and pathological distribution to evaluate whether the presence of amniotic remnants induced inflammatory changes in the lungs. No differences emerged. This study shows that AFA is not a rare event. Even moderate to severe AFA does not necessary cause death. A correlation between AFA and SIDS could not be shown.

  2. Lung ultrasound findings in meconium aspiration syndrome.

    PubMed

    Piastra, Marco; Yousef, Nadya; Brat, Roselyne; Manzoni, Paolo; Mokhtari, Mostafa; De Luca, Daniele

    2014-09-01

    Meconium aspiration syndrome (MAS) is a rare and life-threatening neonatal lung injury induced by meconium in the lung and airways. Lung ultrasound (LUS) is a quick, easy and cheap imaging technique that is increasingly being used in critical care settings, also for newborns. In this paper we describe ultrasound findings in MAS. Six patients with MAS of variable severity were examined by LUS during the first hours of life. Chest X-rays were used as reference. The following dynamic LUS signs were seen in all patients: (1) B-pattern (interstitial) coalescent or sparse; (2) consolidations; (3) atelectasis; (4) bronchograms. No pattern was observed for the distribution of signs in lung areas, although the signs varied with time, probably due to the changing localisation of meconium in the lungs. LUS images corresponded well with X-ray findings. In conclusion, we provide the first formal description of LUS findings in neonates with MAS. LUS is a useful and promising tool in the diagnosis and management of MAS, providing real-time bedside imaging, with the additional potential benefit of limiting radiation exposure in sick neonates.

  3. Current Concepts in the Management of Meconium Aspiration Syndrome.

    PubMed

    Chettri, Subhash; Bhat, B Vishnu; Adhisivam, B

    2016-10-01

    In developing countries, meconium aspiration syndrome (MAS) is an important cause of morbidity and mortality among neonates. The concepts of pathophysiology and management of meconium stained amniotic fluid (MSAF) and meconium aspiration syndrome have undergone tremendous change in recent years. Routine intranatal and postnatal endotracheal suctioning of meconium in vigorous infants is no longer recommended. Recent studies have challenged its role even in non-vigorous infants. Supportive therapy like oxygen supplementation, mechanical ventilation and intravenous fluids are the cornerstone in the management of meconium aspiration syndrome. Availability of surfactant, inhaled nitric oxide, high frequency ventilators and extracorporeal membrane oxygenation has made it possible to salvage more infants with meconium aspiration syndrome. In this review the authors have discussed the current concepts in the pathophysiology and management of MAS. Drugs in trials and future therapeutic targets are also discussed briefly.

  4. Cognitive correlates of adolescents' aspirations to leadership: a developmental study.

    PubMed

    Singer, M

    1990-06-01

    The study examined age and gender differences in leadership aspirations among teenage adolescents. It was hypothesized that adolescents' valence, self-efficacy and attribution perceptions about leadership would be predictive of their aspirations to leadership. Altogether 52 fourth form and 78 seventh form high school students completed a questionnaire measuring (a) overall leadership aspirations, (b) 13 valence-instrumentality expectancies for 13 leadership outcomes, (c) self-efficacy perceptions, and (d) attributions of effective leadership. The results revealed significant gender differences in valence scores and significant age differences in self-efficacy and attribution measures. Regression analyses indicated that fourth formers' leadership aspirations were significantly predicted from their "ease-of-success" self-efficacy expectation; whereas seventh formers from either valence perceptions (males) or self-efficacy and attribution scores (females). These results were discussed in the context of the valence and self-efficacy models of career decision-making processes and attribution theory.

  5. Ultrasound-guided needle aspiration of amoebic liver abscess.

    PubMed Central

    Ramani, A.; Ramani, R.; Kumar, M. S.; Lakhkar, B. N.; Kundaje, G. N.

    1993-01-01

    This prospective study was carried out on 200 patients with clinically, ultrasonographically and serologically confirmed amoebic liver abscess. The role of ultrasound-guided needle aspiration in addition to medications was evaluated compared to drug treatment alone. Both the groups were monitored clinically and sonographically for up to 6 months after diagnosis. The initial response (after 15 days) was better in the aspirated group (P < 0.05) but resolution of abscess after 6 months were similar. There was a more rapid clinical response in the aspirated group, particularly in those with larger (> 6 cm) abscesses and there were no complications. Percutaneous ultrasound-guided needle aspiration is a safe diagnostic and therapeutic approach which enhances clinical recovery, accelerates resolution, especially in large abscesses, and prevents complications. PMID:8346134

  6. Pulmonary aspiration following Dettol poisoning: the scope for prevention.

    PubMed

    Chan, T Y; Critchley, J A

    1996-10-01

    1. After ingestion, Dettol liquid (4.8% chloroxylenol, pine oil, isopropyl, alcohol), a common household disinfectant, can cause central nervous system depression and corrosion of the oral mucosa, larynx and the gastrointestinal tract. The main risk from Dettol poisoning is pulmonary aspiration, leading to pneumonia, adult respiratory distress syndrome (ARDS) and/or sudden cardiorespiratory arrest. 2. To determine to what extent pulmonary aspiration in Dettol poisoning could be prevented, 13 patients treated in a general teaching hospital in Hong Kong were studied. Their clinical details were compared with those of control Dettol poisoning cases without pulmonary aspiration in order to identify possible risk factors for this complication. 3. At presentation, evidence of pulmonary aspiration was present in eight of the 13 patients prior to gastric emptying, but the use of gastric lavage without adequate protection of the airways could have aggravated the problem in three. In two other patients, evidence of aspiration was only present after gastric lavage was performed. The consequences of pulmonary aspiration were pneumonia (n = 10), ARDS (n = 2), acute exacerbation of asthma or chronic obstructive airway disease (n = 2) and sudden cardiorespiratory arrest (n = 1). Three patients with aspiration pneumonia (n = 2), ARDS (n = 1) and/or sudden cardiorespiratory arrest (n = 1) died. 4. Compared with the controls, the median amount of Dettol ingested was considerably larger (400 vs 150 ml), vomiting (100% vs 72.6%) and drowsiness/ confusion (60.2% vs 19.4%) occurred more often. 5. Amongst the 13 patients with Dettol poisoning and pulmonary aspiration, gastric lavage using the nasogastric tube technique without adequate production of the airways had been responsible for the occurrence or worsening of aspiration in two and three patients, respectively. Thus, gastric lavage particularly when using a nasogastric tube appeared to carry more harm than benefits in patients with

  7. From Educational Aspirations to College Enrollment: A Road with Many Paths

    ERIC Educational Resources Information Center

    Liu, Lu

    2009-01-01

    Educational aspiration is one of the most important factors influencing an individual's educational attainment. Although students' aspirations are changeable and the stability of their aspirations is important for their goal reaching, previous studies are rather limited in their ability to capture aspiration changes due to their incomplete…

  8. 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…

  9. Survey of Foreign Body Aspiration in Airways and Lungs

    PubMed Central

    Samarei, R.

    2014-01-01

    Introduction: Foreign body aspiration is a very serious problem and the diversity of clinical protests in each geographic region has its own characteristics and common problems of childhood that is an important cause of mortality and morbidity. No area is separate from this problem and conducting this research is due to achieve basic information regarding foreign body aspiration. Materials and Methods: This was performed as descriptive - cross sectional study on 200 cases that has been hospitalized in Imam Khomeini Hospital, Urmia due to foreign body aspiration problem from 2009 to 2011. And all cases of foreign body aspiration records extracted and analyzed using SPSS 16 software. Results: Foreign body aspiration under 4 years was 57% and was more common in males than females; approximately 74% of patients were hospitalized in the first 10 days and 13% of patients did not remember the initial incident that led to the aspiration. Cough and shortness of breath and reduced lung sounds and wheezing were common symptoms. Chest radiographic findings are not specific and can be normal of a high percentage. The most common aspirated foreign body was food especially sunflower seeds. Right bronchus with 55% of cases was more common than the left bronchus and all patients were treated with rigid bronchoscopy, 24% of patients had complications, 15% had hospitalized with pneumonia. Totally, 75% of patients were urban residents. Discussion: We need to understand all the aspects related to foreign body aspiration and education to the community, to recognize symptoms and type of foreign body in terms of geographical area and to create a strong clinical suspicion in physicians and awareness of its prevalence that by reducing the incidence and early detecting and treatment can reduce the mortality and morbidity and prevent additional expenses. PMID:25363168

  10. A Case of Bipolar Affective Disorder and Aspiration Pneumonia

    PubMed Central

    Dell'Erba, Gaetano

    2013-01-01

    Adults with mental illness are at a higher risk of aspiration pneumonia than the general population. We describe the case of a patient with bipolar affective disorder and two separate episodes of aspiration pneumonia associated with acute mania. We propose that he had multiple predisposing factors, including hyperverbosity, sedative medications, polydipsia (psychogenic and secondary to a comorbidity of diabetes insipidus), and neuroleptic side effects. PMID:23956911

  11. 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

  12. 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

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

    PubMed

    Schindler, Andreas; Bartels, Andreas

    2016-05-24

    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.

  14. Risk of aspiration in care home residents and associated factors.

    PubMed

    van der Maarel-Wierink, Claar D; van der Putten, Gert-Jan; De Visschere, Luc M J; Bronkhorst, Ewald M; de Baat, Cees; Schols, Jos M G A

    2015-02-01

    Pneumonia is a prevalent cause of death in care home residents. Dysphagia is a significant risk factor of aspiration pneumonia. The purpose of the current study was to screen for risk of aspiration in care home residents in the Netherlands and assess potential risk factors of aspiration. Five experienced speech-language therapists assessed 203 care home residents (115 primarily physically disabled, 88 primarily cognitively impaired) 60 and older in the first week after admission to a care home. In 43 (21.2%) residents, speech-language therapists assessed risk of aspiration and found no significant difference between physically disabled (26.1%) and cognitively impaired (14.8%) residents. After multivariate logistic regression analysis, the final prediction model for risk of aspiration showed Parkinson's disease as a significant factor (odds ratio = 5.11; 95% confidence interval [1.49, 17.52]) . The authors therefore conclude that risk of aspiration is a relevant care problem among Dutch care home residents and requires further assessment.

  15. Coevolution of aspirations and cooperation in spatial prisoner's dilemma game

    NASA Astrophysics Data System (ADS)

    Chen, Wei; Wu, Te; Li, Zhiwu; Wang, Long

    2015-01-01

    Suboptimal outcomes are often more acceptable than the best ones when the latter are hard or even impossible to find. In order to describe the emergence of cooperation when suboptimal alternatives prevail, an evolutionary game model is established by considering the effects of aspirations. A win-stay-lose-shift like rule for strategy updating is proposed. The rule prescribes that if the payoff of the current strategy is greater than the aspiration, the strategy remains, otherwise the strategy changes. Aspiration updating allows for individuals to adjust their expected payoff levels. It is shown that suboptimal alternatives can promote the emergence and persistence of cooperation over a wide range of the temptation to defect. Furthermore, a nontrivial phenomenon is found that cooperators prevail as the temptation increases when it is small. The aspirations are stabilized at an intermediate level which can most facilitate cooperation. The obtained results also show that the average level of aspirations decreases as the temptation increases. Furthermore, the variance of aspiration levels is minimized for an intermediate level of temptation.

  16. Neurocontrol in sensory cortex

    NASA Astrophysics Data System (ADS)

    Ritt, Jason; Nandi, Anirban; Schroeder, Joseph; Ching, Shinung

    Technology to control neural ensembles is rapidly advancing, but many important challenges remain in applications, such as design of controls (e.g. stimulation patterns) with specificity comparable to natural sensory encoding. We use the rodent whisker tactile system as a model for active touch, in which sensory information is acquired in a closed loop between feedforward encoding of sensory information and feedback guidance of sensing motions. Motivated by this system, we present optimal control strategies that are tailored for underactuation (a large ratio of neurons or degrees of freedom to stimulation channels) and limited observability (absence of direct measurement of the system state), common in available stimulation technologies for freely behaving animals. Using a control framework, we have begun to elucidate the feedback effect of sensory cortex activity on sensing in behaving animals. For example, by optogenetically perturbing primary sensory cortex (SI) activity at varied timing relative to individual whisker motions, we find that SI modulates future sensing behavior within 15 msec, on a whisk by whisk basis, changing the flow of incoming sensory information based on past experience. J.T.R. and S.C. hold Career Awards at the Scientific Interface from the Burroughs Wellcome Fund.

  17. Risk Factors for Aspiration Pneumonia in Older Adults

    PubMed Central

    Manabe, Toshie; Teramoto, Shinji; Tamiya, Nanako; Okochi, Jiro; Hizawa, Nobuyuki

    2015-01-01

    Backgrounds Aspiration pneumonia is a dominant form of community-acquired and healthcare-associated pneumonia, and a leading cause of death among ageing populations. However, the risk factors for developing aspiration pneumonia in older adults have not been fully evaluated. The purpose of the present study was to determine the risk factors for aspiration pneumonia among the elderly. Methodology and Principal Findings We conducted an observational study using data from a nationwide survey of geriatric medical and nursing center in Japan. The study subjects included 9930 patients (median age: 86 years, women: 76%) who were divided into two groups: those who had experienced an episode of aspiration pneumonia in the previous 3 months and those who had not. Data on demographics, clinical status, activities of daily living (ADL), and major illnesses were compared between subjects with and without aspiration pneumonia. Two hundred and fifty-nine subjects (2.6% of the total sample) were in the aspiration pneumonia group. In the univariate analysis, older age was not found to be a risk factor for aspiration pneumonia, but the following were: sputum suctioning (odds ratio [OR] = 17.25, 95% confidence interval [CI]: 13.16–22.62, p < 0.001), daily oxygen therapy (OR = 8.29, 95% CI: 4.39–15.65), feeding support dependency (OR = 8.10, 95% CI: 6.27–10.48, p < 0.001), and urinary catheterization (OR = 4.08, 95% CI: 2.81–5.91, p < 0.001). In the multiple logistic regression analysis, the risk factors associated with aspiration pneumonia after propensity-adjustment (258 subjects each) were sputum suctioning (OR = 3.276, 95% CI: 1.910–5.619), deterioration of swallowing function in the past 3 months (OR = 3.584, 95% CI: 1.948–6.952), dehydration (OR = 8.019, 95% CI: 2.720–23.643), and dementia (OR = 1.618, 95% CI: 1.031–2.539). Conclusion The risk factors for aspiration pneumonia were sputum suctioning, deterioration of swallowing function, dehydration, and dementia

  18. Semi-Supervised Learning of Cartesian Factors: A Top-Down Model of the Entorhinal Hippocampal Complex

    PubMed Central

    Lőrincz, András; Sárkány, András

    2017-01-01

    The existence of place cells (PCs), grid cells (GCs), border cells (BCs), and head direction cells (HCs) as well as the dependencies between them have been enigmatic. We make an effort to explain their nature by introducing the concept of Cartesian Factors. These factors have specific properties: (i) they assume and complement each other, like direction and position and (ii) they have localized discrete representations with predictive attractors enabling implicit metric-like computations. In our model, HCs make the distributed and local representation of direction. Predictive attractor dynamics on that network forms the Cartesian Factor “direction.” We embed these HCs and idiothetic visual information into a semi-supervised sparse autoencoding comparator structure that compresses its inputs and learns PCs, the distributed local and direction independent (allothetic) representation of the Cartesian Factor of global space. We use a supervised, information compressing predictive algorithm and form direction sensitive (oriented) GCs from the learned PCs by means of an attractor-like algorithm. Since the algorithm can continue the grid structure beyond the region of the PCs, i.e., beyond its learning domain, thus the GCs and the PCs together form our metric-like Cartesian Factors of space. We also stipulate that the same algorithm can produce BCs. Our algorithm applies (a) a bag representation that models the “what system” and (b) magnitude ordered place cell activities that model either the integrate-and-fire mechanism, or theta phase precession, or both. We relate the components of the algorithm to the entorhinal-hippocampal complex and to its working. The algorithm requires both spatial and lifetime sparsification that may gain support from the two-stage memory formation of this complex. PMID:28270783

  19. Semi-Supervised Learning of Cartesian Factors: A Top-Down Model of the Entorhinal Hippocampal Complex.

    PubMed

    Lőrincz, András; Sárkány, András

    2017-01-01

    The existence of place cells (PCs), grid cells (GCs), border cells (BCs), and head direction cells (HCs) as well as the dependencies between them have been enigmatic. We make an effort to explain their nature by introducing the concept of Cartesian Factors. These factors have specific properties: (i) they assume and complement each other, like direction and position and (ii) they have localized discrete representations with predictive attractors enabling implicit metric-like computations. In our model, HCs make the distributed and local representation of direction. Predictive attractor dynamics on that network forms the Cartesian Factor "direction." We embed these HCs and idiothetic visual information into a semi-supervised sparse autoencoding comparator structure that compresses its inputs and learns PCs, the distributed local and direction independent (allothetic) representation of the Cartesian Factor of global space. We use a supervised, information compressing predictive algorithm and form direction sensitive (oriented) GCs from the learned PCs by means of an attractor-like algorithm. Since the algorithm can continue the grid structure beyond the region of the PCs, i.e., beyond its learning domain, thus the GCs and the PCs together form our metric-like Cartesian Factors of space. We also stipulate that the same algorithm can produce BCs. Our algorithm applies (a) a bag representation that models the "what system" and (b) magnitude ordered place cell activities that model either the integrate-and-fire mechanism, or theta phase precession, or both. We relate the components of the algorithm to the entorhinal-hippocampal complex and to its working. The algorithm requires both spatial and lifetime sparsification that may gain support from the two-stage memory formation of this complex.

  20. The extremely low-frequency magnetic field exposure differently affects the AMPAR and NMDAR subunit expressions in the hippocampus, entorhinal cortex and prefrontal cortex without effects on the rat spatial learning and memory.

    PubMed

    Li, Chao; Xie, Meilan; Luo, Fenlan; He, Chao; Wang, Jiali; Tan, Gang; Hu, Zhian

    2014-10-01

    In the present study, we investigated the effects of chronic exposure (14 and 28 days) to a 50 Hz, 0.5 mT extremely low-frequency magnetic field (ELF-MF) on the NMDAR and AMPAR subunit expressions and rat spatial learning and memory. Using the Western blotting method, we found ELF-MF exposure specifically decreased the expressions of GluA2 in the EC post 28 day exposure and GluA3 of AMPAR subunits in the PFC after 14 day exposure, while it did not affect the AMPAR subunit expression in the hippocampus at both time points. As for NMDAR subunits, 14 day ELF-MF exposure significantly increased the levels of GluN2A and GluN2B in the hippocampus. Moreover, the levels of GluN1 and GluN2A were enhanced in the EC and PFC after two weeks of ELF-MF exposure. Interestingly, 28 day ELF-MF exposure induced a different expression pattern for NMDAR subunits. The increased GluN2A expression observed at 14 day post ELF-MF exposure was recovered after prolonged exposure in the hippocampus and PFC. In the EC, the increased expression of GluN1 achieved to control level and, specifically, a decrease in GluN2A level was observed. Surprisingly, neither 14 nor 28 day ELF-MF did affect the rat spatial reference memory as assessed by water maze. These results indicate that the dynamic and brain-region specific changes in ionotropic glutamate receptor expression induced by ELF-MF are insufficient to influence the rat spatial learning ability.

  1. 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

  2. Word Recognition in Auditory Cortex

    ERIC Educational Resources Information Center

    DeWitt, Iain D. J.

    2013-01-01

    Although spoken word recognition is more fundamental to human communication than text recognition, knowledge of word-processing in auditory cortex is comparatively impoverished. This dissertation synthesizes current models of auditory cortex, models of cortical pattern recognition, models of single-word reading, results in phonetics and results in…

  3. Characterization and distribution of (125I)epidepride binding to dopamine D2 receptors in basal ganglia and cortex of human brain

    SciTech Connect

    Joyce, J.N.; Janowsky, A.; Neve, K.A. )

    1991-06-01

    The distribution and pharmacology of the binding of {sup 125}I-epidepride, a substituted benzamide with high affinity and selectivity for dopamine (DA) D2 receptors in rat brain is described in human brain. Saturation analysis of the binding of {sup 125}I-epidepride to membranes derived from striatum and regions of cortex demonstrated similar Kd values (34 and 28-33 pM, respectively) but differing maximum density of binding site values (152 and 3-8 fmol/mg of protein, respectively). The pharmacological profile of binding in cortex was also similar to striatum (epidepride greater than spiperone greater than butaclamol = flupenthixol greater than clozapine) except that an additional low-affinity site, blocked by the alpha-2 adrenergic antagonist idazoxan, was present in cortex. Quantification by autoradiography also demonstrated the greatest binding in the basal ganglia, with the striatum exhibiting greater binding than the pallidal complex or midbrain regions. For the pallidum, binding in the external segment was higher than the internal segment. Within the midbrain the binding of {sup 125}I-epidepride correlated well with the known distribution of DA-containing cell bodies, with the substantia nigra (pars compacta and pars lateralis) and ventral tegmental area (A10) higher than area A8 and central gray. Binding in frontal and parietal cortex was highest in the internal layers (layers V and VI). Temporal cortex showed a 2-fold higher density of binding than other cortical regions and a trilaminar pattern; binding was greater in the external (layers I and II) and internal layers than in the middle layers (III and IV). This pattern changed in the parahippocampal complex. Within the lateral occipitotemporal cortex, binding was densest in layers I to III and very low in layers IV to VI, but binding was almost nonexistent in the adjacent entorhinal cortex.

  4. Laryngeal Elevation Velocity and Aspiration in Acute Ischemic Stroke Patients

    PubMed Central

    Zhang, Jing; Zhou, Yun; Wei, Na; Yang, Bo; Wang, Anxin; Zhou, Hai; Zhao, Xingquan; Wang, Yongjun; Liu, Liping; Ouyoung, Melody; Villegas, Brenda; Groher, Michael

    2016-01-01

    Objectives Aspiration after stroke has been associated with aspiration pneumonia, which contributes to increased mortality of stroke. Laryngeal elevation is a core mechanism for protection from aspiration. Few studies have explored the predictive value of laryngeal elevation velocity for aspiration after stroke. This study aimed to explore the ability of laryngeal elevation velocity to predict aspiration in patients with acute ischemic stroke. Methods This was a prospective cohort study that included consecutive acute ischemic stroke patients treated at a teaching hospital during a 10-month period. Patients underwent magnetic resonance imaging (MRI) to confirm the diagnosis of acute ischemic stroke. Patients who were at risk of aspiration and could swallow 5 ml of diluted barium (40%, w/v) for a videofluoroscopic swallowing (VFS) study were included. The association between abnormal indices in the oral and pharyngeal phase of the VFS study and aspiration was examined using univariate analyses. These indices included the lip closure, tongue movement and control, laryngeal elevation velocity and range, the latency of pharyngeal swallowing, pharyngeal transit time (PTT), abnormal epiglottis tilt, residual barium in the pharynx, and the duration of upper esophageal sphincter (UES) opening. The laryngeal elevation velocity (%/s) was calculated as the range of laryngeal elevation (%) from the resting position to the maximum superior position or to the position where the laryngeal vestibule is fully closed divided by the corresponding duration of laryngeal elevation. The range of laryngeal elevation (%) was the percentage calculated as the distance between the resting laryngeal position and the maximum superior excursion position or position where the laryngeal vestibule is fully closed divided by the distance between the resting laryngeal position and the lowest edge of the mandible. A logistic regression analysis was used to determine the predictive value for aspiration

  5. Electroconvulsive therapy and structural neuroplasticity in neocortical, limbic and paralimbic cortex

    PubMed Central

    Pirnia, T; Joshi, S H; Leaver, A M; Vasavada, M; Njau, S; Woods, R P; Espinoza, R; Narr, K L

    2016-01-01

    Electroconvulsive therapy (ECT) is a highly effective and rapidly acting treatment for severe depression. To understand the biological bases of therapeutic response, we examined variations in cortical thickness from magnetic resonance imaging (MRI) data in 29 patients scanned at three time points during an ECT treatment index series and in 29 controls at two time points. Changes in thickness across time and with symptom improvement were evaluated at high spatial resolution across the cortex and within discrete cortical regions of interest. Patients showed increased thickness over the course of ECT in the bilateral anterior cingulate cortex (ACC), inferior and superior temporal, parahippocampal, entorhinal and fusiform cortex and in distributed prefrontal areas. No changes across time occurred in controls. In temporal and fusiform regions showing significant ECT effects, thickness differed between patients and controls at baseline and change in thickness related to therapeutic response in patients. In the ACC, these relationships occurred in treatment responders only, and thickness measured soon after treatment initiation predicted the overall ECT response. ECT leads to widespread neuroplasticity in neocortical, limbic and paralimbic regions and changes relate to the extent of antidepressant response. Variations in ACC thickness, which discriminate treatment responders and predict response early in the course of ECT, may represent a biomarker of overall clinical outcome. Because post-mortem studies show focal reductions in glial density and neuronal size in patients with severe depression, ECT-related increases in thickness may be attributable to neuroplastic processes affecting the size and/or density of neurons and glia and their connections. PMID:27271858

  6. Thermal blooming on laser propagation in an aspirating pipe

    NASA Astrophysics Data System (ADS)

    Zhu, Fuyin; Wang, Jihong; Ren, Ge; Tan, Yufeng; Zhu, Nengbing; Ai, Zhiwei

    2016-10-01

    Thermal blooming effect of gas on laser propagation can seriously degrade performance of far-field beam quality and energy distribution. Numerical simulation is carried out to study the influences of thermal blooming on laser propagation in line pipes. A physical model of thermal blooming effect of gas on laser propagation in an aspirating pipe is established. Axial flow and suction in the outlet are used to attenuate the thermal blooming effect. Based on the computational fluid dynamics (CFD) software, stable calculation of flow field is carried out first, then the optical field and the fluent field is coupling calculated by means of user defined function (UDF). The results show that radial flow is enhanced in the aspirating pipe and the index of refraction gradient caused by thermal blooming effect is decreased. It is indicated that the beam quality of the outlet is improved compared with the pipe model without aspirating. The optical path difference (OPD) distribution of the outlet is analyzed and decomposed by Zernike polynomials. It is shown that the defocus item of 4m aspirating pipe is decreased more than an order of magnitude compared with the 4m pipe without aspirating.

  7. Dental prosthesis aspiration: An uncommon cause of respiratory distress.

    PubMed

    De Wilde, Belphine A L; Malfait, Thomas L; Bonte, Katrien; Malfait, Thomas L A

    2016-12-01

    We present a case of a 66-year-old Caucasian man with acute respiratory distress. The patient had a history of multiple cerebrovascular accidents which resulted in left hemiplegia, swallowing problems, and aphasia. He was tentatively diagnosed with aspiration pneumonia. However, because of clinical deterioration further investigations concluded to the aspiration of a dental prosthesis. After intubation and stabilization, the prosthesis could be manually extracted. However, the patient developed a Staphylococcus epidermidis sepsis and despite adequate antibiotic therapy, he eventually died. Dental prosthesis aspiration is a medical situation associated with a higher morbidity and mortality rate compared to ingested foreign bodies. It requires a high level of suspicion to ensure a timely diagnosis and life-saving treatment. Thorough history taking is of great importance in case of tracheobronchial aspiration, which is in the adult population mostly secondary to an underlying disorder. In impaired adults with missing dental prostheses there should be extra awareness for this problem. This case report illustrates the importance of a detailed history in case of tracheobronchial aspiration and shows the limitations in the diagnostic usefulness of bedside chest radiography.

  8. ACCURATE TEMPERATURE MEASUREMENTS IN A NATURALLY-ASPIRATED RADIATION SHIELD

    SciTech Connect

    Kurzeja, R.

    2009-09-09

    Experiments and calculations were conducted with a 0.13 mm fine wire thermocouple within a naturally-aspirated Gill radiation shield to assess and improve the accuracy of air temperature measurements without the use of mechanical aspiration, wind speed or radiation measurements. It was found that this thermocouple measured the air temperature with root-mean-square errors of 0.35 K within the Gill shield without correction. A linear temperature correction was evaluated based on the difference between the interior plate and thermocouple temperatures. This correction was found to be relatively insensitive to shield design and yielded an error of 0.16 K for combined day and night observations. The correction was reliable in the daytime when the wind speed usually exceeds 1 m s{sup -1} but occasionally performed poorly at night during very light winds. Inspection of the standard deviation in the thermocouple wire temperature identified these periods but did not unambiguously locate the most serious events. However, estimates of sensor accuracy during these periods is complicated by the much larger sampling volume of the mechanically-aspirated sensor compared with the naturally-aspirated sensor and the presence of significant near surface temperature gradients. The root-mean-square errors therefore are upper limits to the aspiration error since they include intrinsic sensor differences and intermittent volume sampling differences.

  9. Pulmonary aspiration of gastric contents during routine endoscopy

    SciTech Connect

    La France, N.D.; Cole, P.; Wolfe, E.; Giardello, F.; Wagner, H.N.

    1985-05-01

    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. Fever 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.

  10. Prevention and treatment of aspiration pneumonia in intensive care units.

    PubMed

    d'Escrivan, Thibaud; Guery, Benoit

    2005-01-01

    Aspiration is a leading cause of nosocomial infection in the intensive care unit. Techniques to avoid or reduce aspiration are important in preventing pneumonia and pneumonitis. The most important preventive measures include the semi-recumbent position, the surveillance of enteral feeding, the use of promotility agents, and avoiding excessive sedation. The analysis of the pathogens involved in these syndromes usually shows a minor role for the anerobes. With regard to treatment, aspiration pneumonitis does not require any antimicrobials; on the contrary, aspiration pneumonia has to be treated. Empiric antimicrobials treatment should be started on clinical suspicion. The choice of the drug has to be guided by local pathogen epidemiology and clinical features; in fact, community type pneumonia requires a first-line antimicrobial such as amoxicillin/clavulanic acid. On the contrary, a nosocomial type of infection needs to be treated as a ventilator-associated pneumonia in agreement with published guidelines. Nevertheless, quantitative culture should be obtained in order to de-escalate antimicrobials. In conclusion, aspiration pneumonia is a frequently encountered disease that can be prevented by relatively simple measures.

  11. 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.

  12. Aspiration biopsy of testis: another method for histologic examination

    SciTech Connect

    Nseyo, U.O.; Englander, L.S.; Huben, R.P.; Pontes, J.E.

    1984-08-01

    The most important method for evaluating the pathogenesis of male infertility is open testicular biopsy. Herein the authors describe a method of aspiration biopsy of testis for histologic examination. Sexually mature dogs and rats treated with chemotherapeutic agents and ionizing radiation were followed with periodic testicular aspiration biopsy during and after treatment. The histologic findings from the aspiration biopsy compare with the results of routine histologic examination in assessing spermatogenetic activity and delineating pathologic changes. The puncture in the experimental animals was performed under general anesthesia. In human patients testicular biopsy could be done under local anesthesia in an outpatient clinic. The procedure would be less painful, minimally invasive, and more cost-effective.

  13. 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

  14. The Reamer-Irrigator-Aspirator System: A Review.

    PubMed

    Billow, Damien; Khlopas, Anton; Chughtai, Morad; Saleh, Anas; Siqueira, Marcelo B; Marinello, Patrick; Mont, Michael A

    2016-10-26

    The reamer-irrigator-aspirator (RIA) system has been recently developed to decrease the incidence of osseous thermal necrosis and fat embolism associated with intramedullary reaming of long bones in trauma cases. This is achieved by continuous irrigation and suction. Recently, the use of RIA has been expanded to harvest bone graft and debride the medullary canal of long bones in cases of osteomyelitis and intramedullary tumors. Additionally, the collection system of this device has been utilized for its ability to capture bone graft and marrow aspirate. The purpose of this study is to report a comprehensive literature review on the: 1) use of RIA for canal reaming prior to intramedullary nailing; 2) use of RIA for the treatment of intramedullary osteomyelitis of long bones; 3) use of RIA for bone graft harvesting; 4) osteogenic potential of the RIA aspirate; and 5) future applications of the RIA system.

  15. Aspiration prevention protocol: decreasing postoperative pneumonia in heart surgery patients.

    PubMed

    Starks, Bobbie; Harbert, Christy

    2011-10-01

    BACKGROUND Postoperative pneumonia contributes to morbidity and mortality in patients who have open heart surgery. OBJECTIVES To determine if measures to reduce aspiration in patients after cardiothoracic surgery would decrease the occurrence of postoperative pneumonia. METHODS All patients undergoing cardiothoracic surgery from April 2008 through October 2008 were prospectively enrolled in the study. An aspiration prevention protocol was developed and implemented in a 24-bed intensive care unit. The protocol incorporated a bedside swallowing evaluation by a speech therapist and progressive oral intake. RESULTS In the 6 months before development and implementation of the protocol, postoperative pneumonia developed in 11% of patients. After implementation of the protocol, no patients had postoperative pneumonia (P < .01). CONCLUSIONS Implementing an aspiration prevention protocol was effective in reducing the occurrence of postoperative pneumonia in patients who had cardiothoracic surgery.

  16. Aspiration pneumonia in an infant with neurological sequelae - case report.

    PubMed

    Dop, Dalia; Gheonea, Cristian; Stănescu, Georgeta Ligia; Moroşanu, Aritina Elvira; Diaconu, Radu; Niculescu, Elena Carmen; Ognean, Maria Livia; Niculescu, Dragoş

    2015-01-01

    Aspiration pneumonia is a frequent cause of morbidity and mortality in children with neurological deficits. We present the case of a 4-month-old infant from the Foster Care Center, with severe psychomotor retardation, blindness, and associated cardiac malformation, who was admitted to the Pediatrics Clinic of the Emergency County Hospital of Craiova, Romania, presenting aspiration pneumonia and moderate respiratory insufficiency. Under sustained, early instituted treatment, the evolution was towards death. The chest radiography and histopathological examination of the pulmonary tissue confirmed the diagnosis. The neurological impairment was not only a favoring factor for aspiration, through the deglutition disorders, but it was also an aggravating one, through the bacterial colonization of the lungs.

  17. 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.

  18. Evaluation of the lipid-rich layer of reamer aspirate.

    PubMed

    Kay Sinclair, Sarina S; Jeray, Kyle J; Tanner, Stephanie L; Burg, Karen J L

    2010-08-01

    The fatty layer of aspirate obtained by reaming the femoral shaft using a reamer/irrigator/aspirator (RIA) device was characterized for fatty acid content and the presence of adult stem cells. Gas chromatography analysis was performed on samples taken from multiple patients to determine and compare the fatty acid contents of aspirate lipid samples. All four patients had the same four fatty acids present in the highest percentages: oleic, palmitic, linoleic and stearic. After successful isolation from bulk material, cells isolated from this lipid-rich layer were studied to determine their osteogenic and growth potential on a clinically available ceramic bone graft substitute. The results of metabolic activity and intracellular protein assays indicated that the ceramics supported growth of the cells isolated from the aspirate fat layer, although levels of alkaline phosphatase (ALP) expression were low for cells grown on the ceramics. Cells will not transition along the osteogenic pathway when they are actively dividing, and active growth may have contributed to the lack of ALP expression in this study. Isolated cells grown on tissue culture plastic expressed significant levels of the bone marker ALP. The results of this study suggest that cells isolated from the fat layer of RIA aspirate proliferate on ceramic bone void filler and have the potential to differentiate along an osteogenic pathway. Previously considered waste, the lipid-rich fat layer of aspirate may be a source of mesenchymal stem cells that, either alone or in conjunction with currently available synthetic bone graft material, could be used to stimulate new bone growth.

  19. Fine-Needle Aspiration in the Evaluation of Thyroid Neoplasms.

    PubMed

    Oertel, Yolanda C.

    1997-01-01

    Fine-needle aspiration (FNA) is a safe, rapid, and accurate diagnostic tool. Although it continues to gain acceptance, the pace is slow. Probably, if more pathologists master the basics (i.e., learn how to obtain a good sample), this simple technique could be utilized to its fullest advantage. If the sample is not adequate or representative of the lesion, the diagnosis will not be correct. Based on personal experience, we believe that suction should be minimal when obtaining thyroid aspirates. Cytologic diagnostic criteria for the most common neoplasms of the thyroid gland are provided.

  20. AstroBiology Explorer Mission Concepts (ABE/ASPIRE)

    NASA Technical Reports Server (NTRS)

    Sandford, Scott; Ennico, Kimberly A.

    2006-01-01

    The AstroBiology Explorer (ABE) and the Astrobiology Space InfraRed Explorer (ASPIRE) Mission Concepts are two missions designed to address the questions (1) Where do we come from? and (2) Are we alone? as outlined in NASA s Origins Program using infrared spectroscopy to explore the identity, abundance, and distribution of molecules of astrobiological importance throughout the Universe. The ABE mission s observational program is focused on six tasks to: (1) Investigate the evolution of ice and organics in dense clouds and star formation regions, and the young stellar/planetary systems that form in them; (2) Measure the evolution of complex organic molecules in stellar outflows; (3) Study the organic composition of a wide variety of solar system objects including asteroids, comets, and the planets and their satellites; (4) Identify organic compounds in the diffuse interstellar medium and determine their distribution , abundance, and change with environment; (5) Detect and identify organic compounds in other galaxies and determine their dependence on galactic type; and (6) Measure deuterium enrichments in interstellar organics and use them as tracers of chemical processes. The ASPIRE mission s observational program expands upon ABE's core mission and adds tasks that (7) Address the role of silicates in interstellar organic chemistry; and (8) Use different resolution spectra to assess the relative roles and abundances of gas- and solid-state materials. ABE (ASPIRE) achieves these goals using a highly sensitive, cryogenically-cooled telescope in an Earth drift-away heliocentric orbit, armed with a suite of infrared spectrometers that cover the 2.5-20(40) micron spectral region at moderate spectral resolution (R>2000). ASPIRE's spectrometer complement also includes a high-resolution (R>25,000) module over the 4-8 micron spectral region. Both missions target lists are chosen to observe a statistically significant sample of a large number of objects of varied types in

  1. Cytologic findings of tracheobronchial aspirates from 66 thoroughbred racehorses.

    PubMed

    Sweeney, C R; Humber, K A; Roby, K A

    1992-07-01

    Tracheobronchial aspirates obtained from 66 healthy Thoroughbred racehorses in training at the same track were examined. Twenty-seven percent of the horses had greater than 20% neutrophils in the aspirate. Eosinophils, mast cells, giant cells, and Curschmann's spirals of mucus were observed in 94, 83, 65, and 42% of the horses, respectively. Hemosiderophages were observed in 86% of the horses, half of which had previous confirmation of exercise-induced pulmonary hemorrhage. Although fungal elements were seen in 70% of the horses, bacteria were detected in only 3% of the horses. The authors conclude that inflammatory airway disease is widespread in the racing Thoroughbred population.

  2. Cooperation in aspiration-based N -person prisoner's dilemmas

    NASA Astrophysics Data System (ADS)

    Płatkowski, Tadeusz; Bujnowski, Paweł

    2009-03-01

    We propose a mathematical model of the N -person prisoner’s dilemma game played by a continuous population of agents with a time-dependent aspiration level. The model—a system of differential equations—takes into account the evolution of the aspiration level and of the mean frequency of the cooperators in the population. The dependence of the asymptotic level of cooperation on the individual payoffs and on the transition rates determining the agent’s reaction to the received payoffs is studied. In general the existence and the magnitude of the asymptotic level of cooperation depends on N , the payoffs and the transition rates, and decreases with increasing N .

  3. Pulmonary Aspiration of Gastric Acid—Mendelson's Syndrome

    PubMed Central

    Berris, Barnet; Kasler, David

    1965-01-01

    Three cases of pulmonary aspiration of gastric acid as a complication of obstetrical anesthesia are described. The clinical picture consists of dyspnea, cyanosis, tachycardia and shock appearing several hours after the aspiration has occurred. On examination, the chest may be quite clear, but the chest radiograph shows a picture indistinguishable from that of pulmonary edema. The most important therapeutic measure is the intravenous administration of corticosteroids in large doses for several days. Bronchoscopy is contraindicated. With routine use of epidural anesthesia, this obstetrical complication can be avoided. PMID:14289137

  4. Chemosensory Learning in the Cortex

    PubMed Central

    Rolls, Edmund T.

    2011-01-01

    Taste is a primary reinforcer. Olfactory–taste and visual–taste association learning takes place in the primate including human orbitofrontal cortex to build representations of flavor. Rapid reversal of this learning can occur using a rule-based learning system that can be reset when an expected taste or flavor reward is not obtained, that is by negative reward prediction error, to which a population of neurons in the orbitofrontal cortex responds. The representation in the orbitofrontal cortex but not the primary taste or olfactory cortex is of the reward value of the visual/olfactory/taste input as shown by devaluation experiments in which food is fed to satiety, and by correlations of the activations with subjective pleasantness ratings in humans. Sensory-specific satiety for taste, olfactory, visual, and oral somatosensory inputs produced by feeding a particular food to satiety is implemented it is proposed by medium-term synaptic adaptation in the orbitofrontal cortex. Cognitive factors, including word-level descriptions, modulate the representation of the reward value of food in the orbitofrontal cortex, and this effect is learned it is proposed by associative modification of top-down synapses onto neurons activated by bottom-up taste and olfactory inputs when both are active in the orbitofrontal cortex. A similar associative synaptic learning process is proposed to be part of the mechanism for the top-down attentional control to the reward value vs. the sensory properties such as intensity of taste and olfactory inputs in the orbitofrontal cortex, as part of a biased activation theory of selective attention. PMID:21954379

  5. Anatomical pathways for auditory memory II: information from rostral superior temporal gyrus to dorsolateral temporal pole and medial temporal cortex

    PubMed Central

    Muñoz-López, M.; Insausti, R.; Mohedano-Moriano, A.; Mishkin, M.; Saunders, R. C.

    2015-01-01

    Auditory recognition memory in non-human primates differs from recognition memory in other sensory systems. Monkeys learn the rule for visual and tactile delayed matching-to-sample within a few sessions, and then show one-trial recognition memory lasting 10–20 min. In contrast, monkeys require hundreds of sessions to master the rule for auditory recognition, and then show retention lasting no longer than 30–40 s. Moreover, unlike the severe effects of rhinal lesions on visual memory, such lesions have no effect on the monkeys' auditory memory performance. The anatomical pathways for auditory memory may differ from those in vision. Long-term visual recognition memory requires anatomical connections from the visual association area TE with areas 35 and 36 of the perirhinal cortex (PRC). We examined whether there is a similar anatomical route for auditory processing, or that poor auditory recognition memory may reflect the lack of such a pathway. Our hypothesis is that an auditory pathway for recognition memory originates in the higher order processing areas of the rostral superior temporal gyrus (rSTG), and then connects via the dorsolateral temporal pole to access the rhinal cortex of the medial temporal lobe. To test this, we placed retrograde (3% FB and 2% DY) and anterograde (10% BDA 10,000 mW) tracer injections in rSTG and the dorsolateral area 38DL of the temporal pole. Results showed that area 38DL receives dense projections from auditory association areas Ts1, TAa, TPO of the rSTG, from the rostral parabelt and, to a lesser extent, from areas Ts2-3 and PGa. In turn, area 38DL projects densely to area 35 of PRC, entorhinal cortex (EC), and to areas TH/TF of the posterior parahippocampal cortex. Significantly, this projection avoids most of area 36r/c of PRC. This anatomical arrangement may contribute to our understanding of the poor auditory memory of rhesus monkeys. PMID:26041980

  6. MRI volumetry of prefrontal cortex

    NASA Astrophysics Data System (ADS)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was cortex boundaries on 3D images was critical to obtaining accurate measurements. MR prefrontal cortex volumetry by stereology can yield accurate and repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  7. Structure of a micropipette-aspirated vesicle determined from the bending-energy model.

    PubMed

    Chen, Jeff Z Y

    2012-10-01

    The structure of the system consisting of an aspirating pipette and an aspirated vesicle is investigated with fixed total vesicle volume, total vesicle surface area, and aspirated volume fraction, based on the bending-energy model. Through an energetic consideration, the usage of an aspirated volume fraction can be converted to the aspirating pressure for the determination of a phase diagram; the procedure identifies a first-order transition, between a weakly aspirated state and the strongly aspirated state, as the pressure increases. The physical properties of the system are obtained from minimization of the bending energy by an implementation of the simulated annealing Monte Carlo procedure, which searches for a minimum in a multivariable space. An analysis of the hysteresis effects indicates that the experimentally observed aspirating and releasing critical pressures are related to the location of the spinodal points.

  8. 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…

  9. 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.

  10. 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

  11. Does aspiration of bones and joints affect results of later bone scanning

    SciTech Connect

    Canale, S.T.; Harkness, R.M.; Thomas, P.A.; Massie, J.D.

    1985-01-01

    To determine the effect, if any, of needle aspiration on /sup 99m/Tc bone scanning, three different areas of 15 dogs were first aspirated and then imaged with technetium bone scintigraphy. The hip joint was aspirated, the distal femoral metaphysis was drilled and aspirated, and the tibial periosteum was scraped with an 18- or 20-gauge needle. Varying amounts of trauma were inflicted to simulate varying difficulties at aspiration. /sup 99m/Tc bone scans were obtained from 5 h to 10 days later. There was no evidence of focal technetium uptake after any hip joint aspiration. This was consistent regardless of the amount of trauma inflicted or the time from aspiration to bone scanning. Metaphyseal cortical drilling and tibial periosteal scraping occasionally caused some focal uptake when scanning was delayed greater than 2 days. When osteomyelitis or pyarthrosis is clinically suspected, joint aspiration can be performed without fear of producing a false- positive bone scan.

  12. Comparison of the CDC Backpack aspirator and the Prokopack aspirator for sampling indoor- and outdoor-resting mosquitoes in southern Tanzania

    PubMed Central

    2011-01-01

    Background Resting mosquitoes can easily be collected using an aspirating device. The most commonly used mechanical aspirator is the CDC Backpack aspirator. Recently, a simple, and low-cost aspirator called the Prokopack has been devised and proved to have comparable performance. The following study evaluates the Prokopack aspirator compared to the CDC backpack aspirator when sampling resting mosquitoes in rural Tanzania. Methods Mosquitoes were sampled in- and outdoors of 48 typical rural African households using both aspirators. The aspirators were rotated between collectors and households in a randomized, Latin Square design. Outdoor collections were performed using artificial resting places (large barrel and car tyre), underneath the outdoor kitchen (kibanda) roof and from a drop-net. Data were analysed with generalized linear models. Results The number of mosquitoes collected using the CDC Backpack and the Prokopack aspirator were not significantly different both in- and outdoors (indoors p = 0.735; large barrel p = 0.867; car tyre p = 0.418; kibanda p = 0.519). The Prokopack was superior for sampling of drop-nets due to its smaller size. The number mosquitoes collected per technician was more consistent when using the Prokopack aspirator. The Prokopack was more user-friendly: technicians preferred using the it over the CDC backpack aspirator as it weighs considerably less, retains its charge for longer and is easier to manoeuvre. Conclusions The Prokopack proved in the field to be more advantageous than the CDC Backpack aspirator. It can be self assembled using simple, low-cost and easily attainable materials. This device is a useful tool for researchers or vector-control surveillance programs operating in rural Africa, as it is far simpler and quicker than traditional means of sampling resting mosquitoes. Further longitudinal evaluations of the Prokopack aspirator versus the gold standard pyrethrum spray catch for indoor resting catches are recommended. PMID

  13. Effects of coda voicing and aspiration on Hindi vowels

    NASA Astrophysics Data System (ADS)

    Lampp, Claire; Reklis, Heidi

    2001-05-01

    This study reexamines the well-attested coda voicing effect on vowel duration [Chen, Phonetica 22, 125-159 (1970)], in conjunction with the relationship between vowel duration and aspiration of codas. The first step was to replicate the results of Maddieson and Gandour [UCLA Working Papers Phonetics 31, 46-52 (1976)] with a larger, language-specific data set. Four nonsense syllables ending in [open-o] followed by [k, kh, g, gh] were read aloud in ten different carrier sentences by four native speakers of Hindi. Results confirm that longer vowels precede voiced word-final consonants and aspirated word-final consonants. Thus, among the syllables, vowel duration would be longest when preceding the voiced aspirate [gh]. Coda voicing, and thus, vowel duration, have been shown to correlate negatively to vowel F1 in English and Arabic [Wolf, J. Phonetics 6, 299-309 (1978); de Jong and Zawaydeh ibid, 30, 53-75 (2002)]. It is not known whether vowel F1 depends directly on coda voicing, or is determined indirectly via duration. Since voicing and aspiration both increase duration, F1 measurements of this data set (which will be presented) may answer that question.

  14. Parental Involvement, Children's Aspirations, and Achievement in New Immigrant Families

    ERIC Educational Resources Information Center

    Jung, Eunjoo; Zhang, Yue

    2016-01-01

    The authors investigated the relationships among multiple aspects of parental involvement (English proficiency, school involvement, control and monitoring of children), children's aspirations, and achievement in new immigrant families in the United States. They used data on immigrant parents and school-age children (N = 1,255) from the New…

  15. Uncertainty in Early Occupational Aspirations: Role Exploration or Aimlessness?

    ERIC Educational Resources Information Center

    Staff, Jeremy; Harris, Angel; Sabates, Ricardo; Briddell, Laine

    2010-01-01

    Many youth in the United States lack clear occupational aspirations. This uncertainty in achievement ambitions may benefit socio-economic 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…

  16. Failing Young People? Education and Aspirations in a Deprived Community

    ERIC Educational Resources Information Center

    Sinclair, S.; McKendrick, J. H.; Scott, G.

    2010-01-01

    Recent UK government statements and education policies have emphasized the need to instil a "culture of aspiration" among young people in deprived communities to address social exclusion. Specific proposals include raising the school leaving age to 18 and extending compulsory employment training. These statements and measures express the…

  17. Personal Commitment: A Prerequisite for Women Aspiring to Educational Administration.

    ERIC Educational Resources Information Center

    Moore, Colleen A.

    The decline in the number and status of women in educational administration and the magnitude of their lack of representation in administrative positions is evidenced by numerous studies. To achieve the goal of identifying the components of the problem, solutions suggested by the research, and implications for women who aspire to administrative…

  18. 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.

  19. Aspiration Levels and Educational Choices: An Experimental Study

    ERIC Educational Resources Information Center

    Page, Lionel; Garboua, Louis Levy; Montmarquette, Claude

    2007-01-01

    The explanation of social inequalities in education is still a debated issue in economics. Recent empirical studies tend to downplay the potential role of credit constraint. This article tests a different potential explanation of social inequalities in education, specifically that social differences in aspiration level result in different…

  20. Auditing Inequity: Teaching Aspiring Administrators to Be Social Justice Leaders

    ERIC Educational Resources Information Center

    Hernandez, Frank; Marshall, Joanne

    2017-01-01

    While much has been written about preparing educational leaders to lead for social justice, much less has been written about how to do so. This study is one of the first to analyze the reflections and written assignments of aspiring administrators to determine what they are currently thinking about poverty, race/ethnicity, and social justice…

  1. Women Teachers' Aspirations to School Leadership in Uganda

    ERIC Educational Resources Information Center

    Sperandio, Jill; Kagoda, Alice Merab

    2010-01-01

    Purpose: The under-representation of women in the leadership of secondary schooling is a problem common to many developing countries, raising issues of social justice and sustainable development. It has its roots in societal understandings about leadership, the schooling and career aspirations of girls, the organizational characteristics of the…

  2. Needed: A Valid Measure of Women's Career Aspirations.

    ERIC Educational Resources Information Center

    Lentz, Linda P.

    As part of a longitudinal study of women's and coeducational college graduates, women's career salience ratings and aspirations were compared. Participants were 1979 female graduates of 15 small, private, liberal arts colleges in the northeastern United States that had three selectivity levels: selective, very selective, and highly selective. A…

  3. Subject Choice and Occupational Aspirations among Pupils at Girls' Schools

    ERIC Educational Resources Information Center

    Francis, Becky; Hutchings, Merryn; Archer, Louise; Amelling, Lindsay

    2003-01-01

    Various studies have found that British girls' curriculum subject preferences and future aspirations have changed and diversified in recent years. Other work has suggested that girls educated in single-sex schools might have a different (perhaps less gender-stereotypical) experience of education in comparison with their contemporaries at…

  4. Latino Males Degree Aspirations in Community College: A Qualitative Study

    ERIC Educational Resources Information Center

    Dorame, Francisco

    2012-01-01

    Latino males are the least likely to attend, persist, and attain a baccalaureate degree compared to other male groups in higher education. Moreover, they tend to have the lowest degree aspirations of any major race or ethnic group (Saenz & Ponjuan, 2009; Driscoll, 2007; Swail, Cabrera, & Lee, 2004; Laanan, 2000; Kao & Tienda, 1998). To…

  5. College Aspirations and Preparation: How AVID Students Beat the Odds

    ERIC Educational Resources Information Center

    Cronin, Dana

    2013-01-01

    A study of "at risk" high school youth revealed how student participation in the Advancement Via Individual Determination (AVID) program positively affected student achievement and increased college aspirations and entrance rates. The experiences of the students, teachers, and administrators were examined using a case study approach…

  6. The Career Aspirations of Rural Appalachian High School Students

    ERIC Educational Resources Information Center

    Ali, Saba Rasheed; Saunders, Jodi L.

    2009-01-01

    The purpose of the present study was to investigate the contributions of several social cognitive career theory (SCCT) factors in predicting the career aspirations of a group of high school students living in the central part of rural Appalachia. Sixty-three high school students completed measures assessing their vocational/educational…

  7. Career Aspirations of Undergraduate Mathematics Majors: An Exploratory Study

    ERIC Educational Resources Information Center

    Piotrowski, Chris; Hemasinha, Rohan

    2012-01-01

    There has been much research attention on ability level, motivation, and self-efficacy of students at schools of science, technology, engineering and mathematics (STEM). However, there is scant research on vocational choice, career development and aspirations of these students. The current study addresses this gap in the literature by asking…

  8. The Evolution of Roles and Aspirations: Burgeoning Choices for Females.

    ERIC Educational Resources Information Center

    Scott, Robert A.

    Traditional female status, roles, and aspirations and changes that have occurred in American society are traced. While women were barred from colleges and universities in the 1800's, they now account for more than 50 percent of college students. It is projected that by the year 2000, women will represent an even larger percentage of the college…

  9. Desired Mobility or Satisfied Immobility? Migratory Aspirations among Knowledge Workers

    ERIC Educational Resources Information Center

    Ferro, Anna

    2006-01-01

    Among the aspects discussed within the globalisation process, the international mobility of professional workers assumes considerable relevance. This paper focuses on migratory aspirations among knowledge workers within the context of economic globalisation and market restructuring in Romania. Due to a lack of literature dealing with these issues,…

  10. Aspirations, Expectations, and Attitudes of South Carolina High School Students.

    ERIC Educational Resources Information Center

    Boyd, Virlyn A.

    Forty-two representative South Carolina high schools were surveyed via similar, group administered questionnaires in 1966-67 (5,400 sophomore students) and again in 1969-69 (4,376 senior students) to determine: (1) the aspirations and expectations of South Carolina youth with regard to occupation, education, marriage and family size, future…

  11. Searching for Autonomy: Young Black Men, Schooling and Aspirations

    ERIC Educational Resources Information Center

    Law, Ian; Finney, Sarah; Swann, Sarah Jane

    2014-01-01

    This article examines the relationships between being young and black, and educational and career aspirations, drawing on new research evidence from two recent studies carried out in two urban locations in Northern England. The first of these studies forms part of a wider research project concerned with analysing the connections between aspects of…

  12. First-Year Student Aspirations: A Multinodal Analysis

    ERIC Educational Resources Information Center

    Grellier, Jane

    2014-01-01

    This article explores the aspirations of first-year university students in a particular socio-geographic context, by juxtaposing this context with those of Western universities in the 1970s. The rhizomatic analysis enables student voices and personal narratives to complement, extend and undercut the words of published researchers and of the…

  13. The Hierarchical Personality Structure of Aspiring Creative Writers

    ERIC Educational Resources Information Center

    Maslej, Marta M.; Rain, Marina; Fong, Katrina; Oatley, Keith; Mar, Raymond A.

    2014-01-01

    Empirical studies of personality traits in creative writers have demonstrated mixed findings, perhaps due to issues of sampling, measurement, and the reporting of statistical information. The goal of this study is to quantify the personality structure of aspiring creative writers according to a modern hierarchal model of trait personality. A…

  14. Effects of coda voicing and aspiration on Hindi vowels

    NASA Astrophysics Data System (ADS)

    Lampp, Claire; Reklis, Heidi

    2004-05-01

    This study reexamines the well-attested coda voicing effect on vowel duration [Chen, Phonetica 22, 125-159 (1970)], in conjunction with the relationship between vowel duration and aspiration of codas. The first step was to replicate the results of Maddieson and Gandour [UCLA Working Papers Phonetics 31, 46-52 (1976)] with a larger, language-specific data set. Four nonsense syllables ending in [open-o] followed by [k, kh, g, gh] were read aloud in ten different carrier sentences by four native speakers of Hindi. Results confirm that longer vowels precede voiced word-final consonants and aspirated word-final consonants. Thus, among the syllables, vowel duration would be longest when preceding the voiced aspirate [gh]. Coda voicing, and thus, vowel duration, have been shown to correlate negatively to vowel F1 in English and Arabic [Wolf, J. Phonetics 6, 299-309 (1978); de Jong and Zawaydeh ibid, 30, 53-75 (2002)]. It is not known whether vowel F1 depends directly on coda voicing, or is determined indirectly via duration. Since voicing and aspiration both increase duration, F1 measurements of this data set (which will be presented) may answer that question.

  15. The Intangibles: Advice for New and Aspiring Heads

    ERIC Educational Resources Information Center

    Walsh, Matthew J.

    2010-01-01

    For those who have just been appointed to their first headship or who are aspiring to be a head of school, they undoubtedly know the importance of the mechanics of finance, curriculum, development, and trustee work. These are critical to their success. After four years of headship, however, the author has come to learn that the intangibles can be…

  16. Adolescent Boys' Science Aspirations: Masculinity, Capital, and Power

    ERIC Educational Resources Information Center

    Archer, Louise; DeWitt, Jennifer; Willis, Beatrice

    2014-01-01

    There is widespread international concern about post-16 participation rates in science, with women's under-representation constituting a particular issue. This paper contributes to these debates through a novel, critical examination of the role of masculinity within boys' negotiations of science aspirations. Drawing on a UK longitudinal study of…

  17. 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.

  18. Pulmonary Paragonimiasis Diagnosed by Fine-Needle Aspiration Biopsy▿

    PubMed Central

    Zarrin-Khameh, Neda; Citron, Deborah R.; Stager, Charles E.; Laucirica, Rodolfo

    2008-01-01

    We report a case of paragonimiasis involving a 12-year-old Latin American boy. The diagnosis was made by fine-needle aspiration biopsy of a pulmonary nodule. Identification of the species by morphometric analysis of the eggs indicated that the infection was caused by Paragonimus mexicanus. PMID:18385444

  19. Tracheoesophageal Fistula Secondary to Esophageal Carcinoma Presenting With Aspiration Pneumonia

    PubMed Central

    Adler, Leon; Kabnick, Earl M.; Patel, Mahendra; Azueta, Victor; Helfgott, Andrew; Alexander, Leslie L.; Tafreshi, Mahmood

    1985-01-01

    Tracheoesophageal fistulas should be suspected in patients with recurring chronic aspiration pneumonitis. They are most often secondary to intrathoracic malignancies. A case report of a patient with this disorder is presented, along with a review of pertinent literature. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:3999155

  20. Acute pneumonia in Zimbabwe: bacterial isolates by lung aspiration.

    PubMed Central

    Ikeogu, M O

    1988-01-01

    Forty children, aged 2 months to 11 years, with severe acute pneumonia were investigated by needle aspiration of the lung. Fourteen organisms were isolated in only 13 patients. Streptococcus pneumoniae was isolated in six patients, Staphylococcus aureus in three, and Haemophilus influenzae in two. Two patients had mixed organisms. PMID:3196056

  1. Foreign body aspiration pneumonia in an intravenous drug user

    PubMed Central

    Bhaskar, Balu; Andelkovic, Vladimir

    2012-01-01

    Heroin use is associated with several well described respiratory complications, including noncardiogenic pulmonary edema, aspiration pneumonitis, acute respiratory distress syndrome,pneumonia, lung abscess, septic pulmonary emboli, and atelectasis. We describe an interesting case of a young female patient, an intravenous heroin user who presented with progressive dyspnea, hypoxia, and left lung consolidation. PMID:22412782

  2. An Unusual Case of Foreign Body Aspiration in an Infant

    PubMed Central

    Dias, E

    2012-01-01

    Inhalation of foreign body is a serious condition in childhood and may result in acute respiratory distress, lung injury or death. A nine month old baby with history of severe respiratory distress, cyanosis and gasping breathing diagnosed as foreign body aspiration due to a balloon which was recovered post mortem during the removal of the endotracheal tube. PMID:23439996

  3. Aspire Public Schools: Building the Organizational Capacity for Healthy Growth

    ERIC Educational Resources Information Center

    Saxton, Amy; Perigo, Mike

    2008-01-01

    Two years into an aggressive expansion plan, Aspire Public Schools was on track in terms of school openings, but behind on its goals to add a layer of management. The schools were performing well, but the nonprofit's leaders were stretched paper thin and concerned about the organization's ability to perform in the face of more growth. Determined…

  4. The anaesthetic consideration of tracheobronchial foreign body aspiration in children

    PubMed Central

    2016-01-01

    Cases of tracheobronchial foreign body aspiration are frequently encountered emergency cases of childhood; and, delays in its recognition and treatment do result in serious morbidity and mortality. Diagnosis mainly relies on taking history which should indicate what the foreign body is, when it has been aspirated and where it is located. Belated consultation can cause misdiagnosis with the mixing of the symptoms and data with those of other pathologies common to childhood and further delays in the correct diagnosis. Bronchoscopy is required for the differential diagnosis of suspected tracheobronchial foreign body aspiration in order to eliminate other common pediatric respiratory concerns. Given the shared use of the airways by the surgeon and the anaesthesiologist, bronchoscopy is a challenging procedure requiring experienced teams with an efficient method of intercommunication, and also well planning of the anaesthesia and bronchoscopy ahead of the procedures. Despite the recent popularisation of the fiberoptic brochoscopes, the rigid bronchoscopy remains to be used commonly and is regarded to provide the gold standard technique. There have been reports in the literature on the uses of inhalation and/or intravenous (IV) anaesthesia and spontaneous or controlled ventilation methods without any demonstration of the superiority of one technique over the other. The most suitable methods of anaesthesia and ventilation would be those that reduce the risks of complications, morbidity and mortality; and, preventive measures should be taken with priority against childhood cases of tracheobronchial foreign body aspiration. PMID:28149580

  5. Aspirations for a Master's-Level Teaching Profession in England

    ERIC Educational Resources Information Center

    Thomas, Lorraine

    2016-01-01

    This research investigates aspirations for a master's-level teaching profession in England, providing key stakeholder perceptions in one densely populated region within a multiple case study. Although this intended move to a master's-level profession represented a major shift in teachers' professional development in England, only limited…

  6. Aspiring Principal Development Programme Evaluation in New Zealand

    ERIC Educational Resources Information Center

    Piggot-Irvine, Eileen; Youngs, Howard

    2011-01-01

    Purpose: The New Zealand Ministry of Education has constructed a wide-ranging "Professional Development Plan" providing a four-stage national pathway for progression to principalship; the first stage has been the conduction of the National Aspiring Principals Pilot (NAPP) programme in five regional locations. The purpose of this paper is…

  7. Factors Affecting the Career Aspirations of Asian Americans.

    ERIC Educational Resources Information Center

    Leung, S. Alvin

    This study examined the career aspirations of Asian American college students, using a retrospective method of data collection that asked subjects to report various occupational alternatives that they have considered in their lifetime so far. Male (N=52) and female (N=97) Asian Americans were compared with a Euro-American group of 95 males and 151…

  8. 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.; Hamilton, D. R.

    2002-01-01

    BACKGROUND: As a medical emergency that can affect even well-screened, healthy individuals, peritonitis developing during a long-duration space exploration mission may dictate deviation from traditional clinical practice due to the absence of otherwise indicated surgical capabilities. Medical management can treat many intra-abdominal processes, but treatment failures are inevitable. In these circumstances, percutaneous aspiration under sonographic guidance could provide a "rescue" strategy. Hypothesis: Sonographically guided percutaneous aspiration of intra-peritoneal fluid can be performed in microgravity. METHODS: Investigations were conducted in the microgravity environment of NASA's KC-135 research aircraft (0 G). The subjects were anesthetized female Yorkshire pigs weighing 50 kg. The procedures were rehearsed in a terrestrial animal lab (1 G). Colored saline (500 mL) was introduced through an intra-peritoneal catheter during flight. A high-definition ultrasound system (HDI-5000, ATL, Bothell, WA) was used to guide a 16-gauge needle into the peritoneal cavity to aspirate fluid. RESULTS: Intra-peritoneal fluid collections were easily identified, distinct from surrounding viscera, and on occasion became more obvious during weightless conditions. Subjectively, with adequate restraint of the subject and operators, the procedure was no more demanding than during the 1-G rehearsals. CONCLUSIONS: Sonographically guided percutaneous aspiration of intra-peritoneal fluid collections is feasible in weightlessness. Treatment of intra-abdominal inflammatory conditions in spaceflight might rely on pharmacological options, backed by sonographically guided percutaneous aspiration for the "rescue" of treatment failures. While this risk mitigation strategy cannot guarantee success, it may be the most practical option given severe resource limitations.

  9. The supramammillary nucleus and the claustrum activate the cortex during REM sleep

    PubMed Central

    Renouard, Leslie; Billwiller, Francesca; Ogawa, Keiko; Clément, Olivier; Camargo, Nutabi; Abdelkarim, Mouaadh; Gay, Nadine; Scoté-Blachon, Céline; Touré, Rouguy; Libourel, Paul-Antoine; Ravassard, Pascal; Salvert, Denise; Peyron, Christelle; Claustrat, Bruno; Léger, Lucienne; Salin, Paul; Malleret, Gael; Fort, Patrice; Luppi, Pierre-Hervé

    2015-01-01

    Evidence in humans suggests that limbic cortices are more active during rapid eye movement (REM or paradoxical) sleep than during waking, a phenomenon fitting with the presence of vivid dreaming during this state. In that context, it seemed essential to determine which populations of cortical neurons are activated during REM sleep. Our aim in the present study is to fill this gap by combining gene expression analysis, functional neuroanatomy, and neurochemical lesions in rats. We find in rats that, during REM sleep hypersomnia compared to control and REM sleep deprivation, the dentate gyrus, claustrum, cortical amygdaloid nucleus, and medial entorhinal and retrosplenial cortices are the only cortical structures containing neurons with an increased expression of Bdnf, FOS, and ARC, known markers of activation and/or synaptic plasticity. Further, the dentate gyrus is the only cortical structure containing more FOS-labeled neurons during REM sleep hypersomnia than during waking. Combining FOS staining, retrograde labeling, and neurochemical lesion, we then provide evidence that FOS overexpression occurring in the cortex during REM sleep hypersomnia is due to projections from the supramammillary nucleus and the claustrum. Our results strongly suggest that only a subset of cortical and hippocampal neurons are activated and display plasticity during REM sleep by means of ascending projections from the claustrum and the supramammillary nucleus. Our results pave the way for future studies to identify the function of REM sleep with regard to dreaming and emotional memory processing. PMID:26601158

  10. 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…

  11. Structural and Socio-Psychological Influences on Adolescents' Educational Aspirations and Subsequent Academic Achievement

    ERIC Educational Resources Information Center

    Rothon, Catherine; Arephin, Muna; Klineberg, Emily; Cattell, Vicky; Stansfeld, Stephen

    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…

  12. Career Decision-Making, Career Barriers and Occupational Aspirations in Chinese Adolescents

    ERIC Educational Resources Information Center

    Creed, Peter A.; Wong, Oi Yin; Hood, Michelle

    2009-01-01

    The study tested the relationship between occupational aspirations/expectations (type and status) and decision-making difficulties, efficacy and career barriers in 498 Chinese high school students. Males aspired to investigative and enterprising types, but expected realistic and enterprising ones; females aspired to enterprising and conventional…

  13. Exploring the Factors that Influence Men and Women to Form Medical Career Aspirations.

    ERIC Educational Resources Information Center

    Antony, James Soto

    1998-01-01

    Medical-career aspirations prior to college are examined in longitudinal data (N=27,065; 59.1% female). Men and women aspire to medical careers at roughly the same rate and for mostly the same reasons, but the strength of influence varies significantly for certain factors. Fewer women maintain medical-career aspirations during college. (Author/EMK)

  14. 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…

  15. Validity of Vocational Aspirations and Interest Inventories: Extended, Replicated, and Reinterpreted.

    ERIC Educational Resources Information Center

    Holland, John L.; And Others

    1990-01-01

    Found classified vocational aspirations of 467 male and 250 female Navy recruits superior to Vocational Preference Inventory (VPI). Predictions for subjects with coherent vocational aspirations were very predictive over short time interval. Hypothesized links between coherence of vocational aspirations and Identity Scale, NEO Personality Inventory…

  16. 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…

  17. Intrinsic Aspirations and Personal Meaning across Adulthood: Conceptual Interrelations and Age/Sex Differences

    ERIC Educational Resources Information Center

    Morgan, Jessica; Robinson, Oliver

    2013-01-01

    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,…

  18. Use of the reamer-irrigator-aspirator technique to obtain autograft for ankle and hindfoot arthrodesis.

    PubMed

    Herscovici, D; Scaduto, J M

    2012-01-01

    The use of autograft bone is the best option when undertaking a procedure that requires bone graft because it is osteogenic, osteoconductive and osseo-inductive. Pain, morbidity and complications associated with harvesting iliac or non-iliac sites occur in between 6% and 30% of cases. An alternative source of graft with possibly a lower morbidity is the intramedullary canal. In this study, 28 patients undergoing 30 arthrodesis procedures on the hindfoot had a mean of 48 cm(3) (43 to 50) of bone harvested locally from the hindfoot or the tibial shaft by antegrade or retrograde reaming. No patient sustained a fracture of the calcaneum, talus or tibia. There was no morbidity except for one complication when the reamer breached the medial tibial cortex. This healed uneventfully. This method of using the reamer-irrigator-aspirator system is an extension of the standard technique of intramedullary reaming of the lower limb: it produces good-quality bone graft with viable growth factors consistent with that of the iliac crest, and donor site morbidity is low. This is an efficient method of obtaining autologous bone for use in arthrodesis of the ankle or hindfoot.

  19. Human GV oocytes generated by mitotically active germ cells obtained from follicular aspirates

    PubMed Central

    Ding, Xinbao; Liu, Guishu; Xu, Bo; Wu, Changqing; Hui, Ning; Ni, Xin; Wang, Jian; Du, Meirong; Teng, Xiaoming; Wu, Ji

    2016-01-01

    Human female germline stem cells (FGSCs) have opened new opportunities for understanding human oogenesis, delaying menopause, treating infertility, and providing a new strategy for preserving fertility. However, the shortage of adult human ovaries tissues available impedes their future investigations and clinical applications. Here, we have established FGSC lines from scarce ovarian cortical tissues that exist in follicular aspirates (faFGSCs), which are produced and discarded in in vitro fertilization centers worldwide. The faFGSCs have characteristics of germline stem cells involved in the gene expression profile, growth characteristics, and a normal karyotype consistent with that of FGSCs obtained from ovarian cortexes surgically removed from patients (srFGSCs). Furthermore, faFGSCs have developmental potentials including spontaneous differentiation into oocytes under feeder-free conditions, communicating with granulosa cells by gap junctions and paracrine factors, entering meiosis after RA induction, as well as forming follicles after injection into human ovarian cortical tissues xenografted into adult immunodeficient female mice. Lastly, we developed a strategy guiding FGSCs differentiated into germinal vesicle (GV) stage oocytes in vitro and revealed their developmental mechanisms. Our study not only provides a new approach to obtain human FGSCs for medical treatment, but also opens several avenues to investigate human oogenesis in vitro. PMID:27357640

  20. 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

  1. 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

  2. Development of adrenal cortex zonation.

    PubMed

    Xing, Yewei; Lerario, Antonio M; Rainey, William; Hammer, Gary D

    2015-06-01

    The human adult adrenal cortex is composed of the zona glomerulosa (zG), zona fasciculata (zF), and zona reticularis (zR), which are responsible for production of mineralocorticoids, glucocorticoids, and adrenal androgens, respectively. The final completion of cortical zonation in humans does not occur until puberty with the establishment of the zR and its production of adrenal androgens; a process called adrenarche. The maintenance of the adrenal cortex involves the centripetal displacement and differentiation of peripheral Sonic hedgehog-positive progenitors cells into zG cells that later transition to zF cells and subsequently zR cells.

  3. Causal Evidence for the Role of Specific GABAergic Interneuron Types in Entorhinal Recruitment of Dentate Granule Cells

    PubMed Central

    Lee, Cheng-Ta; Kao, Min-Hua; Hou, Wen-Hsien; Wei, Yu-Ting; Chen, Chin-Lin; Lien, Cheng-Chang

    2016-01-01

    The dentate gyrus (DG) is the primary gate of the hippocampus and controls information flow from the cortex to the hippocampus proper. To maintain normal function, granule cells (GCs), the principal neurons in the DG, receive fine-tuned inhibition from local-circuit GABAergic inhibitory interneurons (INs). Abnormalities of GABAergic circuits in the DG are associated with several brain disorders, including epilepsy, autism, schizophrenia, and Alzheimer disease. Therefore, understanding the network mechanisms of inhibitory control of GCs is of functional and pathophysiological importance. GABAergic inhibitory INs are heterogeneous, but it is unclear how individual subtypes contribute to GC activity. Using cell-type-specific optogenetic perturbation, we investigated whether and how two major IN populations defined by parvalbumin (PV) and somatostatin (SST) expression, regulate GC input transformations. We showed that PV-expressing (PV+) INs, and not SST-expressing (SST+) INs, primarily suppress GC responses to single cortical stimulation. In addition, these two IN classes differentially regulate GC responses to θ and γ frequency inputs from the cortex. Notably, PV+ INs specifically control the onset of the spike series, whereas SST+ INs preferentially regulate the later spikes in the series. Together, PV+ and SST+ GABAergic INs engage differentially in GC input-output transformations in response to various activity patterns. PMID:27830729

  4. A study of underlying variables affecting aspirations of rural adolescents.

    PubMed

    Quaglia, R J; Perry, C M

    1995-01-01

    Aspirations are comprised of two major components--inspiration and ambition. Ambitions represents the ability to look ahead and invest in the future. Inspiration can be described as the ability to invest the time, energy, and effort to reach those ambitions. Variables such as how and why students spend their time illustrate the dynamics of these two components. The data in this report are based on the responses to the Aspirations Survey of 2,677 eighth- to twelfth-grade students from seven rural schools in Maine. The data suggest that many students have no understanding of why they engage in certain activities. If students are to be responsible for their education and more importantly for themselves, they must see purpose in their pursuits.

  5. Suicidal Ideation and Migration Aspirations among Youth in Central Mexico

    PubMed Central

    Hoffman, Steven

    2014-01-01

    Over the past 100 years the state of Guanajuato has consistently been one of the highest migrant sending states in Mexico. Youth living in high migratory states such as Guanajuato are heavily influenced by the expectation that they will travel to the US, and research has shown that those who do not migrate may be looked down upon by members of their community. This secondary analysis looks at the connection between suicidal ideation and migration aspirations among a group of adolescents living in Guanajuato, Mexico. Data were originally collected in 2007 as part of a comprehensive health survey of youth attending an alternative high schooling program. Regression analyses show that suicidal ideation predicts intentions to migrate among both males and females, while other factors differentially influence the adolescents by gender. The results indicate that suicidal ideation may be associated with migration aspirations among Mexican youth living in high migratory communities. Study limitations and implications are discussed. PMID:24373268

  6. How to overcome surfactant dysfunction in meconium aspiration syndrome?

    PubMed

    Mokra, Daniela; Calkovska, Andrea

    2013-06-01

    Surfactant dysfunction in meconium aspiration syndrome (MAS) is caused by meconium components, by plasma proteins leaking through the injured alveolocapillary membrane and by substances originated in meconium-induced inflammation. Surfactant inactivation in MAS may be diminished by several ways. Firstly, aspirated meconium should be removed from the lungs to decrease concentrations of meconium inhibitors coming into the contact with surfactant in the alveolar compartment. Once the endogenous surfactant becomes inactivated, components of surfactant should be substituted by exogenous surfactant at a sufficient dose, and surfactant administration should be repeated, if oxygenation remains compromised. To delay the inactivation by inhibitors, exogenous surfactants may be enriched with surfactant proteins, phospholipids, or other substances such as polymers. Finally, to diminish an adverse action of products of meconium-induced inflammation on both endogenous and exogenously delivered surfactant, anti-inflammatory drugs may be administered. A combined therapeutic approach may result in better outcome in patients with MAS and in lower costs of treatment.

  7. Massive reflux and aspiration after radiographically inserted gastrostomy tube placement.

    PubMed

    Chesoni, Sandra A; Bach, John R; Okamura, Erica Mia

    2015-01-01

    To the authors' knowledge, fatal postgastrostomy aspiration within 2 days of enteral nutrition has not been reported. The authors report consecutive cases of severe postgastrotomy aspiration with one being fatal for a 26-yr-old with Duchenne muscular dystrophy 2 days after initiation of gastrostomy feedings. Previous to these consecutive radiographically inserted gastrostomies, all gastrotomies at the institution were percutaneous endoscopic gastrostomies or open gastrostomies. Radiographically inserted gastrostomy tubes have an increased likelihood of being oriented toward the esophagus as opposed to the duodenum, which may increase the risk for reflux. Elimination of invasive airway tubes should be delayed until after gastrostomy feedings are documented to be well tolerated. Oximetry and repeated measurements of vital capacity can suggest changes in the status of airway clearance.

  8. [Aspiration syndrome due to laryngeal cleft in an infant].

    PubMed

    Cuestas, Giselle; Demarchi, Victoria; Zanetta, Adrián; Urquizo, Mauricio; Lobos, Pablo; Razetti, Juan

    2014-02-01

    Aspiration is the passage of food content and endogenous secretions into the airway. Anatomical, neuromuscular or functional anomalies are among the major causes. The laryngeal cleft is a rare congenital anomaly that should be considered in the differential diagnosis of aspiration syndrome in neonates and infants. The main symptoms are stridor, recurrent respiratory infections and cyanotic crisis, cough and choking during feeding. The diagnosis is confirmed by endoscopic examination. The therapeutic behaviour will depend on the extent of the cleft, among other factors. We describe the clinical manifestations, diagnostic methods and treatment of an infant with this disease, and we emphasize the need for recognition of swallowing disorders in children in order to establish an accurate diagnosis and appropriate treatment to prevent and avoid malnutrition as well as a severe and potentially irreversible lung compromise.

  9. Suicidal ideation and migration aspirations among youth in central Mexico.

    PubMed

    Hoffman, Steven

    2013-10-16

    Over the past 100 years the state of Guanajuato has consistently been one of the highest migrant sending states in Mexico. Youth living in high migratory states such as Guanajuato are heavily influenced by the expectation that they will travel to the US, and research has shown that those who do not migrate may be looked down upon by members of their community. This secondary analysis looks at the connection between suicidal ideation and migration aspirations among a group of adolescents living in Guanajuato, Mexico. Data were originally collected in 2007 as part of a comprehensive health survey of youth attending an alternative high schooling program. Regression analyses show that suicidal ideation predicts intentions to migrate among both males and females, while other factors differentially influence the adolescents by gender. The results indicate that suicidal ideation may be associated with migration aspirations among Mexican youth living in high migratory communities. Study limitations and implications are discussed.

  10. Behavior of liquid metal droplets in an aspirating nozzle. Revision

    SciTech Connect

    Swank, W.D.; Fincke, J.R.; Mason, T.A.

    1990-12-31

    Measurements of particle size, velocity, and relative mass flux were made on spray field produced by aspirating liquid tin into 350{degrees}C argon flowing through a venturi nozzle via a small orifice in the throat of the nozzle. Details of the aspiration and droplet formation process were observed through windows in the nozzle. The spatial distribution of droplet size, velocity, and relative number density were measured at a location 10 mm from the nozzle exit. Due to the presence of separated flow in the nozzle, changes in nozzle inlet pressure did not significantly effect resulting droplet size and velocity. This suggests that good aerodynamic nozzle design is required if spray characteristics are to be controlled by nozzle flow. 5 refs.

  11. Behavior of liquid metal droplets in an aspirating nozzle

    SciTech Connect

    Swank, W.D.; Fincke, J.R.; Mason, T.A.

    1990-01-01

    Measurements of particle size, velocity, and relative mass flux were made on spray field produced by aspirating liquid tin into 350{degrees}C argon flowing through a venturi nozzle via a small orifice in the throat of the nozzle. Details of the aspiration and droplet formation process were observed through windows in the nozzle. The spatial distribution of droplet size, velocity, and relative number density were measured at a location 10 mm from the nozzle exit. Due to the presence of separated flow in the nozzle, changes in nozzle inlet pressure did not significantly effect resulting droplet size and velocity. This suggests that good aerodynamic nozzle design is required if spray characteristics are to be controlled by nozzle flow. 5 refs.

  12. Stainless steel crown aspiration during sedation in pediatric dentistry.

    PubMed

    Adewumi, A; Kays, David W

    2008-01-01

    Foreign body aspiration (FBA) causes death in more than 300 children every year in the United States. Morbidity and mortality are increased in children due to narrow airways and immature protective mechanisms. Factors to consider in pediatric dentistry are: (1) the patient's age and behavior; (2) presence and extent of disability; (3) local anesthesia; (4) body positioning; and (5) loose teeth. FBA requires prompt recognition and early treatment to minimize potentially serious and sometimes fatal consequences. The purpose of this case report was to describe the aspiration of a stainless steel crown in a 5-year-old boy during conscious sedation. It also discusses how a prompt and accurate diagnosis, early referral, and immediate treatment helped prevent serious complications.

  13. Art in Science Promoting Interest in Research and Exploration (ASPIRE)

    NASA Astrophysics Data System (ADS)

    Fillingim, M.; Zevin, D.; Thrall, L.; Croft, S.; Raftery, C.; Shackelford, R.

    2015-11-01

    Led by U.C. Berkeley's Center for Science Education at the Space Sciences Laboratory in partnership with U.C. Berkeley Astronomy, the Lawrence Hall of Science, and the YMCA of the Central Bay Area, Art in Science Promoting Interest in Research and Exploration (ASPIRE) is a NASA EPOESS-funded program mainly for high school students that explores NASA science through art and highlights the need for and uses of art and visualizations in science. ASPIRE's aim is to motivate more diverse young people (especially African Americans) to learn about Science, Technology, Engineering, and Mathematics (STEM) topics and careers, via 1) Intensive summer workshops; 2) Drop-in after school workshops; 3) Astronomy visualization-focused outreach programming at public venues including a series of free star parties where the students help run the events; and 5) A website and a number of social networking strategies that highlight our youth's artwork.

  14. Aspiring and Residing IT Leaders: A Legacy for the Future

    ERIC Educational Resources Information Center

    McIntosh, Keith W.

    2012-01-01

    Many people think there is a quick road to leadership success. Those who want to become IT leaders--that is, "aspiring leaders"--often think: "If I just do my job well, I will rise to a leadership position." Those who are already IT leaders--that is, "residing leaders"--often think: "If I just do my job well, I will leave a lasting legacy." Doing…

  15. Primary pulmonary botryomycosis: a late complication of foreign body aspiration

    PubMed Central

    Tuggey, J; Hosker, H; DaCosta, P

    2000-01-01

    Primary pulmonary botryomycosis is a rare cause of haemoptysis and can enter the differential diagnosis of a mass on the plain chest radiograph. The case history is presented of a 63 year old man with botryomycosis which was initially thought to be a bronchial carcinoma. When the diagnosis was made several years later it was found to be secondary to persisting vegetable material in the bronchial tree following previous aspiration.

 PMID:11083895

  16. Aspiration tests in aqueous foam using a breathing simulator

    SciTech Connect

    Archuleta, M.M.

    1995-12-01

    Non-toxic aqueous foams are being developed by Sandia National Laboratories (SNL) for the National Institute of Justice (NIJ) for use in crowd control, cell extractions, and group disturbances in the criminal justice prison systems. The potential for aspiration of aqueous foam during its use and the resulting adverse effects associated with complete immersion in aqueous foam is of major concern to the NIJ when examining the effectiveness and safety of using this technology as a Less-Than-Lethal weapon. This preliminary study was designed to evaluate the maximum quantity of foam that might be aspirated by an individual following total immersion in an SNL-developed aqueous foam. A.T.W. Reed Breathing simulator equipped with a 622 Silverman cam was used to simulate the aspiration of an ammonium laureth sulfate aqueous foam developed by SNL and generated at expansion ratios in the range of 500:1 to 1000:1. Although the natural instinct of an individual immersed in foam is to cover their nose and mouth with a hand or cloth, thus breaking the bubbles and decreasing the potential for aspiration, this study was performed to examine a worst case scenario where mouth breathing only was examined, and no attempt was made to block foam entry into the breathing port. Two breathing rates were examined: one that simulated a sedentary individual with a mean breathing rate of 6.27 breaths/minute, and one that simulated an agitated or heavily breathing individual with a mean breathing rate of 23.7 breaths/minute. The results of this study indicate that, if breathing in aqueous foam without movement, an air pocket forms around the nose and mouth within one minute of immersion.

  17. Perfectionism and life aspirations in intrinsically and extrinsically religious individuals.

    PubMed

    Steffen, Patrick R

    2014-08-01

    Religiosity is related to positive health and life satisfaction but the pathways through which this occurs have not been clearly delineated. The purpose of this study was to examine potential mediators of the relationships between intrinsic and extrinsic religiosity and negative affect and life satisfaction. Perfectionism and life aspirations are two possible pathways through which religious orientation is related to outcome. It was hypothesized that adaptive perfectionism and intrinsic life aspirations would act as mediators between intrinsic religiosity and negative affect and life satisfaction, and that maladaptive perfectionism and extrinsic life aspirations would act as mediators between the extrinsic religiosity and negative affect and life satisfaction. Two consecutive samples of religious college students (N = 540 and N = 485) completed measures of the Age Universal Religious Orientation Index, the Frost Multi-Dimensional Perfectionism Scale, the Aspiration Index, the Beck Depression Inventory-II, the Spielberger State-Trait Anxiety Inventory, and the Satisfaction with Life Scale. Intrinsic religiosity had a direct negative relationship with negative affect and positive relationship with life satisfaction. Contrary to the hypotheses, intrinsic religiosity had its strongest indirect effect via maladaptive perfectionism such that increased intrinsic religiosity was related to decreased maladaptive perfectionism which in turn lead to better negative affect and life satisfaction. Extrinsic religiosity was related to increased maladaptive perfectionism and thereby indirectly contributed to worse negative affect and life satisfaction. Interestingly, when the effects of maladaptive perfectionism were controlled, the direct effects of extrinsic religiosity were related to reduced negative affect and increased life satisfaction. Overall, the strongest mediator in this study of both intrinsic and extrinsic religiosity was maladaptive perfectionism, with intrinsic

  18. Use of Videofluoroscopic Swallowing Study in Patients with Aspiration Pneumonia

    PubMed Central

    Park, Seunglee; Lee, Jin-Youn; Jung, Heeyoune; Koh, Seong-Eun; Lee, In-Sik; Yoo, Kwang Ha; Lee, Seung Ah

    2012-01-01

    Objective To investigate the clinical characteristics of dysphagic elderly Korean patients diagnosed with aspiration pneumonia as well as to examine the necessity of performing a videofluoroscopic swallowing study (VFSS) in order to confirm the presence of dysphagia in such patients. Method The medical records of dysphagic elderly Korean subjects diagnosed with aspiration pneumonia were retrospectively reviewed for demographic and clinical characteristics as well as for VFSS findings. Results In total, medical records of 105 elderly patients (81 men and 24 women) were reviewed in this study. Of the 105 patients, 82.9% (n=87) were admitted via the emergency department, and 41.0% (n=43) were confined to a bed. Eighty percent (n=84) of the 105 patients were diagnosed with brain disorders, and 68.6% (n=72) involved more than one systemic disease, such as diabetes mellitus, cancers, chronic cardiopulmonary disorders, chronic renal disorders, and chronic liver disorders. Only 66.7% (n=70) of the 105 patients underwent VFSS, all of which showed abnormal findings during the oral or pharyngeal phase, or both. Conclusion In this study, among 105 dysphagic elderly patients with aspiration pneumonia, only 66.7% (n=70) underwent VFSS in order to confirm the presence of dysphagia. As observed in this study, the evaluation of dysphagia is essential in order to consider elderly patients with aspiration pneumonia, particularly in patients with poor functional status, brain disorders, or more than one systemic disease. A greater awareness of dysphagia in the elderly, as well as the diagnostic procedures thereof, particularly VFSS, is needed among medical professionals in Korea. PMID:23342310

  19. Riedel thyroiditis: Fine needle aspiration findings of a rare entity.

    PubMed

    Weidner, Anna-Sophie; Molina, David; DeSimone, Robert A; Cohen, Marc A; Giorgadze, Tamar; Scognamiglio, Theresa; Hoda, Rana S

    2015-09-01

    Riedel thyroiditis is a rare fibrosing disorder characterized by extension of the fibroinflammatory process beyond the thyroid capsule. Due to the nature of this lesion, fine-needle aspiration often yields scant material and may be interpreted as non-diagnostic. In this report, we describe cytologic features that allow the cytopathologist to favor a diagnosis of Riedel thyroiditis, thereby guiding appropriate further work-up and management.

  20. Aspiration-based partner switching boosts cooperation in social dilemmas.

    PubMed

    Li, Zhi; Yang, Zhihu; Wu, Te; Wang, Long

    2014-01-01

    Most previous studies concerning linking dynamics often assumed that links pairing individuals should be identified and treated differently during topology adjusting procedure, in order to promote cooperation. A common assumption was that cooperators were expected to avoid being exploited by quickly breaking up relationships with defectors. Then the so-called prosocial links linking two cooperators (abbreviated as CC links hereafter) would be much favored by evolution, whereby cooperation was promoted. However, we suggest that this is not always necessary. Here, we developed a minimal model in which an aspiration-based partner switching mechanism was embedded to regulate the evolution of cooperation in social dilemmas. Individuals adjusted social ties in a self-questioning manner in line with the learning theory. Less game information was involved during dynamic linking and all links were tackled anonymously irrespective of their types (i.e., CD links, DD links, or CC links). The main results indicate that cooperation flourishes for a broad range of parameters. The denser the underlying network, the more difficult the evolution of cooperation. More importantly, moderate aspirations do much better in promoting the evolution of altruistic behavior and for most cases there exists the optimal aspiration level that most benefits cooperation. Too strong or too weak selection intensity turns out to be pretty conducive to the evolution of cooperation in such a dynamical system.

  1. Numerical determination of personal aerosol sampler aspiration efficiency.

    PubMed

    Lo Savio, Simone; Paradisi, Paolo; Tampieri, Francesco; Belosi, Franco; Morigi, Maria Pia; Agostini, Sergio

    2003-04-01

    In this work the determination of the aspiration efficiency of personal aerosol samplers, commonly used in occupational exposure assessment, is investigated by means of CFD techniques. Specifically, it will be described a code to calculate the particle trajectories in a given flow field. At the present state the code considers only the effects of the mean flow field on the particle motion, whereas the turbulent diffusion effects are neglected. Comparisons with experimental measurements are also given in the framework of a research contract, supported by the European Community, with several experimental contributions from the participants. The main objective of the European research is to develop a new approach to experimentation with airborne particle flows, working on a reduced scale. This methodology has the advantage of allowing real-time aerosol determination and use of small wind tunnels, with a better experimental control. In this article we describe how the methodology has been verified using computational fluid dynamics. Experimental and numerical aspiration efficiencies have been compared and the influence of gravity and turbulence intensity in full and reduced scale has been investigated. The numerical techniques described here are in agreement with previous similar research and allow at least qualitative predictions of aspiration efficiency for real samplers, taking care of orientation from the incoming air flow. The major discrepancies among predicted and experimental results may be a consequence of bounce effects, which are very difficult to eliminate also by greasing the sampler surface.

  2. Aspiration pneumonia: experimental evaluation of albumin and steroid therapy.

    PubMed Central

    Toung, T J; Bordos, D; Benson, D W; Carter, D; Zuidema, G D; Permutt, S; Cameron, J L

    1976-01-01

    An experimental model using an ex vivo perfused ventilated canine pulmonary lobe was used to study aspiration pneumonia. After intrabronchial acid instillation, the lobe weight tripled, air way pressure and pulmonary artery pressure doubled, and intrapulmonary shunting increased from 5.5% to 53.4%. If large quantities of albumin were added to the lobe perfusate 5 minutes after intrabronchial acid instillation, weight gain, air way and pulmonary artery pressure, and intrapulmonary shunting were unchanged from control levels. If large quantities of steroid were added to the lobe perfusate 5 minutes after intrabronchial acid instillation, the lobe weight doubled but air way pressure and pulmonary artery pressure, and intrapulmonary shunting were not significantly different from control values. It is surmised that intrapulmonary acid aspiration causes an immediate and marked changed in pulmonary capillary permeability. Albumin administration by counteracting this permeability change, and steroid administration by modifying the permeability change, are both beneficial following acid aspiration. Images Fig. 7a. Fig. 7a., Fig. 7c. PMID:1247316

  3. Food Particle Aspiration Associated with Hemorrhagic Shock: A Diagnostic Dilemma.

    PubMed

    Tashtoush, Basheer; Schroeder, Jonathan; Memarpour, Roya; Oliveira, Eduardo; Medina, Michael; Hadeh, Anas; Ramirez, Jose; Smolley, Laurence

    2015-01-01

    The hemodynamic compromise caused by a large aspirated food particle in the airway can become the focus of medical attention and a distraction from rare but fatal Heimlich maneuver related injuries after an incident of food aspiration. We herein present a case of an 84-year-old man who was brought to the emergency department after an episode of choking at a restaurant followed by several failed Heimlich maneuver attempts. Despite relieving the airway obstruction by extracting a large piece of steak from the airway, the patient remained hypotensive and required continued hemodynamic support. Repeated laboratory tests within 24 hrs of aspiration showed a significant decline in the hemoglobin level. A computed tomography (CT) scan of the abdomen and pelvis showed a lacerated liver with a large subcapsular hematoma draining into the pelvis. Conclusion. Hepatic rupture is a rare complication of Heimlich maneuver; this paper represents the second case report in the literature. It emphasizes the necessity of early identification and surveillance of fatal Heimlich maneuver complications in a high risk population.

  4. Food Particle Aspiration Associated with Hemorrhagic Shock: A Diagnostic Dilemma

    PubMed Central

    Schroeder, Jonathan; Memarpour, Roya; Oliveira, Eduardo; Medina, Michael; Smolley, Laurence

    2015-01-01

    The hemodynamic compromise caused by a large aspirated food particle in the airway can become the focus of medical attention and a distraction from rare but fatal Heimlich maneuver related injuries after an incident of food aspiration. We herein present a case of an 84-year-old man who was brought to the emergency department after an episode of choking at a restaurant followed by several failed Heimlich maneuver attempts. Despite relieving the airway obstruction by extracting a large piece of steak from the airway, the patient remained hypotensive and required continued hemodynamic support. Repeated laboratory tests within 24 hrs of aspiration showed a significant decline in the hemoglobin level. A computed tomography (CT) scan of the abdomen and pelvis showed a lacerated liver with a large subcapsular hematoma draining into the pelvis. Conclusion. Hepatic rupture is a rare complication of Heimlich maneuver; this paper represents the second case report in the literature. It emphasizes the necessity of early identification and surveillance of fatal Heimlich maneuver complications in a high risk population. PMID:26090241

  5. Population coding in somatosensory cortex.

    PubMed

    Petersen, Rasmus S; Panzeri, Stefano; Diamond, Mathew E

    2002-08-01

    Computational analyses have begun to elucidate which components of somatosensory cortical population activity may encode basic stimulus features. Recent results from rat barrel cortex suggest that the essence of this code is not synergistic spike patterns, but rather the precise timing of single neuron's first post-stimulus spikes. This may form the basis for a fast, robust population code.

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

    SciTech Connect

    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 a 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.

  7. Social interaction with a cagemate in pain facilitates subsequent spinal nociception via activation of the medial prefrontal cortex in rats.

    PubMed

    Li, Zhen; Lu, Yun-Fei; Li, Chun-Li; Wang, Yan; Sun, Wei; He, Ting; Chen, Xue-Feng; Wang, Xiao-Liang; Chen, Jun

    2014-07-01

    Empathy for the pain experience of others can lead to the activation of pain-related brain areas and can even induce aberrant responses to pain in human observers. Recent evidence shows this high-level emotional and cognitive process also exists in lower animals; however, the mechanisms underlying this phenomenon remain unknown. In the present study we found that, after social interaction with a rat that had received subcutaneous injection of bee venom (BV), only the cagemate observer (CO) but not the noncagemate observer (NCO) showed bilateral mechanical hypersensitivity and an enhanced paw flinch reflex following BV injection. Moreover, neuronal activities labeled by c-Fos immunoreactivity in the spinal dorsal horn of CO rats were also significantly increased relative to the control 1 hour after BV injection. A stress-related response can be excluded because serum corticosterone concentration following social interaction with demonstrator rats in pain was not changed in CO rats relative to NCO and isolated control rats. Anxiety can also be excluded because anxiety-like behaviors could be seen in both the CO and NCO rats tested in the open-field test. Finally, bilateral lesions of the medial prefrontal cortex eliminated the enhancement of the BV-induced paw flinch reflex in CO rats, but bilateral lesions of either the amygdala or the entorhinal cortex failed. Together, we have provided another line of evidence for the existence of familiarity-dependent empathy for pain in rats and have demonstrated that the medial prefrontal cortex plays a critical role in processing the empathy-related enhancement of spinal nociception.

  8. 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…

  9. The rat cortex in stereotaxic coordinates.

    PubMed

    Schober, W

    1986-01-01

    On the basis of Nissl-preparations the cortex of albino rats has been mapped cytoarchitectonically. 13 frontal sections through the cortex are illustrated with coordinates. Therewith exists a stereotaxic atlas of the cortex of the rat and one can realize exactly experimental investigations in the different cortical areas.

  10. The Functions of the Orbitofrontal Cortex

    ERIC Educational Resources Information Center

    Rolls, Edmund T.

    2004-01-01

    The orbitofrontal cortex contains the secondary taste cortex, in which the reward value of taste is represented. It also contains the secondary and tertiary olfactory cortical areas, in which information about the identity and also about the reward value of odours is represented. The orbitofrontal cortex also receives information about the sight…

  11. On the presence of dendrite bundles in the cerebral cortex of the Madagascan lesser hedgehog tenrec and the red-eared pond turtle.

    PubMed

    Schmolke, C; Künzle, H

    1997-09-01

    In mammals with a well-differentiated neocortex apical dendrites of pyramidal cells form vertical bundles. Little is known about the presence of dendrite bundles in animals with a poorly differentiated cortex. In this paper the presence of dendrite bundles has been investigated in the lesser hedgehog tenrec, Echinops telfairi, a basal insectivore with a very low degree of neocorticalization. In a further step the arrangement of dendrites has been analyzed in the cerebral cortex of the red-eared pond turtle, Pseudemys scripta elegans. Among non-mammalian vertebrates, reptiles have a cerebral cortex that is relatively most comparable with the mammalian one, and the cerebral cortex of turtles shows more structural and functional similarities with the cortex in mammals than those of other reptiles. In the hedgehog tenrec, bundles of apical dendrites are found in all neo-cortical areas, the cingulate and retrosplenial cortices. The shape and arrangement of dendrite bundles are primarily determined by apical dendrites of lamina V pyramids. Apical dendrites originating in laminae III/IV or VI join these bundles, and do not give rise to separate sets of bundles in the supra- and infragranular layers as in other mammals. Center to center distances between bundles determined in the neocortical areas A(2-4) range from 7 to 76 microm, with an average of 32 microm. Area-specific differences are found concerning the length of bundles as well as the number, caliber, branching pattern and packing density of dendrites sharing an individual bundle. In the three-layered entorhinal cortex and the hippocampus dendrite bundles are not observed. In the turtle, no vertical bundles of dendrites are seen either in the medial, dorsomedial or medial part of the dorsal cortex. Only in the lateral part of the dorsal cortex are isolated bundles of apical dendrites originating from groups of perikarya situated below the main level of lamina II detected. Our findings suggest that the presence of

  12. 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

  13. Total laryngectomy for management of chronic aspiration pneumonia in a myopathic dog.

    PubMed

    Vernau, Karen M; Marks, Stanley L; Kuhn, Maggie A; Culp, William T N; Owens, Tammy J; Shelton, G Diane; Siddiqui, Tausif; Pollard, Rachel; Belafsky, Peter C

    2016-07-01

    A 5-month-old female pit bull terrier dog evaluated for ataxia, progressive regurgitation, and recurrent aspiration pneumonia had markedly elevated creatine kinase activity, non-inflammatory generalized myopathy, and severe esophageal dysmotility. A narrow-field total laryngectomy was performed. The dog is doing well 30 months after surgery, and no longer has episodes of aspiration pneumonia, despite intermittent regurgitation. This case represents the first application of total laryngectomy for the prevention of chronic recurrent aspiration pneumonia in the dog.

  14. Inadequate fine needle aspiration biopsy samples: Pathologists versus other specialists

    PubMed Central

    Gomez-Macías, GS; Garza-Guajardo, R; Segura-Luna, J

    2009-01-01

    Background: Fine needle aspiration biopsy (FNAB) is a simple, sensitive, quick and inexpensive method in which operator experience is essential for obtaining the best results. Methods: A descriptive study in which the aspiration biopsy cases of the Pathology and Cytopathology Service of the University Hospital of the UANL (2003–2005) were analyzed. These were divided into three study groups: Group 1, FNAB performed by a pathologist; Group 2, FNAB performed by specialists who are not pathologists, Group 3, FNAB guided by an imaging study with immediate evaluation by a pathologist. The samples were classified as adequate and inadequate for diagnosis, the organ, the size and characteristics of the lesions were taken into consideration. Results: A total of 1905 FNAB were included. In Group 1: 1347 were performed of which 1242 (92.2%) were adequate and 105 (7.7%) were inadequate. Of the 237 from Group 2, 178 were adequate (75.1%) and 59 inadequate (24.8%); in Group 3 there were 321 of which 283 (88.1%) were adequate and 38 (11.8%) inadequate. A statistically significant difference was found between FNAB performed by Group 1 (p< 0.001) and the other groups. A multivariate analysis was done where the organ punctured, the study groups, the size and characteristics of the lesion by study group were compared, finding that the most important variable was the person who performed the procedure. Conclusion: The experience and training of the person performing the aspiration biopsy, as well as immediate evaluation of the material when it is guided, substantially reduces the number of inadequate samples, improving the sensitivity of the method as well as reducing the need for open biopsies to reach a diagnosis. PMID:19621092

  15. Fine-needle aspiration biopsy: a historical overview.

    PubMed

    Rosa, Marilin

    2008-11-01

    Fine needle aspiration biopsy is a safe, inexpensive and accurate technique for the diagnosis of benign and malignant conditions. Its increase in popularity in the present days has made it a technique used on daily basis in the majority of medical centers in United States and around the world. However, the situation was not always like this. In its beginnings the procedure suffered from all kinds of criticism and attacks. The purpose of this manuscript is to provide an overview about the development of this technique from its birth to our days.

  16. Granulomatous lung disease in children by aspiration of medications.

    PubMed

    Hański, W; Figurski, R; Fermus, R

    1987-01-01

    Post mortem examinations of 8 infants, 11 d to 5 months old and one 12 year old girl, demonstrated foreign bodies in the lungs which could be identified as orally administered drugs: cholestyramine (Questran) and phenobarbital (Luminal, Gardenal) or phenydantin-components. The microscopic changes caused by such deposits and the histologic methods of identifying medicines are presented. The authors point to the role of aspiration in deposit formation and to the pseudomiliary granulomatous nature of subsequent changes. It is proposed to define the alterations as a separate form of aspiratory lesion in children.

  17. Aspiration of tracheoesophageal prosthesis in a laryngectomized patient

    PubMed Central

    2012-01-01

    Background The voice prosthesis inserted into a tracheoesophageal fistula has become the most widely used device for voice rehabilitation in patients with total laryngectomy. Case presentation We describe a case of tracheoesophageal prosthesis’ (TEP) aspiration in a laryngectomized patient, with permanent tracheal stoma, that appeared during standard cleaning procedure, despite a programme of training for the safe management of patients with voice prosthesis. Conclusions The definitive diagnosis and treatment were performed by flexible bronchoscopy, that may be considered the procedure of choice in these cases, also on the basis of the literature. PMID:22958961

  18. Fine needle aspiration cytology of thymic carcinoid tumor.

    PubMed

    Wang, D Y; Kuo, S H; Chang, D B; Yang, P C; Lee, Y C; Hsu, H C; Luh, K T

    1995-01-01

    Carcinoid tumors of the thymus are very rare, and their cytologic findings have not been reported previously in English. Retrospective study of fine needle aspiration (FNA) cytologic features in four histopathologically verified thymic carcinoid tumors are described here in detail. The FNA cytology of thymic carcinoids is characterized by predominantly single and some loose clusters of small, round to oval cells with scanty cytoplasm, interspersed with some larger cells with moderate to abundant, granular cytoplasm. The differential diagnosis of the cytologic features between carcinoid tumor and other mediastinal tumors is also discussed.

  19. Meconium aspiration syndrome treatment - new approaches using old drugs.

    PubMed

    Ivanov, Vadim A

    2006-01-01

    Presently, modern medicine does not offer any disease-modifying treatment for meconium aspiration syndrome (MAS). Several medications with already established safety profiles when employed for similar or other conditions could be useful for MAS treatment. N-Acetylcysteine and DNAse have the capability to reduce viscosity and thickness of meconium by breaking disulfide bonds and slicing DNA, respectively. N-Acetylcysteine, antiprotease drugs, or low pH buffer solutions may have the capability to neutralize meconium's digestive enzymes responsible for lung damage in patients with MAS. All these compounds have great potential to reduce meconium's pathogenic properties which in turn could alleviate MAS severity.

  20. Metastatic Chordoma: A Diagnostic Challenge on Fine Needle Aspiration

    PubMed Central

    Tranesh, Ghassan; Nassar, Aziza

    2016-01-01

    Chordomas are primary low grade malignant tumors of bone that usually arise within both ends of axial skeleton. The Notochord is a midline, ectoderm-derived structure that defines the phylum of chordates. Chordomas may pose difficult diagnostic challenges when encountered in secondary locations, such as lungs or other parenchymatous organs. We report the cytologic findings of a metastatic chordoma sampled through CT-scan guided fine needle aspiration (FNA) of lower lobe lung nodule in a 54-year-old man diagnosed with recurrent chordoma involving the lumber spine and paraspinal region. PMID:26881166

  1. Laryngospasm With Apparent Aspiration During Sedation With Nitrous Oxide.

    PubMed

    Babl, Franz E; Grindlay, Joanne; Barrett, Michael Joseph

    2015-11-01

    Nitrous oxide and oxygen mixture has become increasingly popular for the procedural sedation and analgesia of children in the emergency department. In general, nitrous oxide is regarded as a very safe agent according to large case series. We report a case of single-agent nitrous oxide sedation of a child, complicated by laryngospasm and radiographically confirmed bilateral upper lobe pulmonary opacities. Although rarely reported with parenteral sedative agents, laryngospasm and apparent aspiration has not been previously reported in isolated nitrous oxide sedation. This case highlights that, similar to other sedative agents, nitrous oxide administration also needs to be conducted by staff and in settings in which airway emergencies can be appropriately managed.

  2. Sclerosing hemangioma: A diagnostic dilemma in fine needle aspiration cytology

    PubMed Central

    Zeng, Jennifer; Zhou, Fang; Wei, Xiao-Jun; Kovacs, Sandor; Simsir, Aylin; Shi, Yan

    2016-01-01

    Sclerosing hemangioma of the lung is a benign neoplasm with a widely debated histogenesis. It has a polymorphic histomorphology characterized by a biphasic cell population of “surface cells” and “round cells” arranged in four general patterns: Papillary, solid, angiomatous, and sclerotic. This variability in histomorphology makes it difficult to diagnose sclerosing hemangioma by fine needle aspiration (FNA). We present a case of sclerosing hemangioma diagnosed on FNA with immunohistochemistry performed on an accompanied cell block. The clinical presentation, cytomorphology, immunohistochemistry, and differential diagnoses are discussed. PMID:27168758

  3. Perineal nodule due to enterobiasis: an aspiration cytologic diagnosis.

    PubMed

    Kumar, Neeta; Sharma, Prashant; Sachdeva, Ritesh; Jain, Shyama

    2003-01-01

    Subcutaneous swelling due to Enterobious vermicularis infection is rare. Their presence in perineal subcutaneous tissue is unusual and a clinical curiosity. A case of subcutaneous nodule in the perineum due to E. vermicularis infection diagnosed on fine-needle aspiration is described. Tissue reaction was granulomatous with neutrophils and eosinophils. Lack of familiarity with the morphology of parasites or its eggs, degeneration, and inadequate sampling may make the diagnosis difficult. This case report provides the morphologic clues to cytopathologists toward rendering a diagnosis and alerts them to the possibility of parasitic infection in unusual locations.

  4. Optical evaluation of red blood cell geometry using micropipette aspiration.

    PubMed

    Engström, K G; Möller, B; Meiselman, H J

    1992-01-01

    Although red blood cell (RBC) geometry has been extensively studied by micropipette aspiration, the small size of RBC and pipettes vs. the optical resolution of light microscopy suggests the need to consider potential errors. The present study addressed such difficulties and investigated four specific problems: (1) use of exact equations to calculate RBC membrane area and volume; (2) calibration of the pipette internal diameter (PID); (3) correction for a noncylindrical pipette barrel; (4) diffraction distortion of the RBC image. The observed PID represents a cylinder lens enlargement that can be theoretically derived from the glass/buffer refractive index ratio (1.49/1.33 = 1.12). This enlargement was experimentally confirmed by: (1) studying pipettes bent to allow measurement through the barrel (horizontal) and at the orifice (vertical), with a resulting diameter ratio of 1.12 +/- 0.01; (2) and by replacing the surrounding buffer with immersion oil and hence abolishing the lens phenomenon (ratio = 1.12 +/- 0.02). In addition, use of aspirated oil droplets demonstrated a 3.2 +/- 0.2% error when the PID is focused at a sharp, maximum diameter. The average pipette cone angle was 1.49 +/- 0.09 degrees and varied considerably with pipette pulling procedures; calculated tongue geometry inside the pipette was affected by the noncylindrical pipette barrel. The RBC diffraction error, demonstrated by touching two aspirated cells held by opposing pipettes, was 0.091 +/- 0.002 microns. The PID, cone angle, and diffraction artifacts significantly (p < 0.001) affected calculated RBC geometry (average errors up to 5.4% for area and 9.6% for volume). Two new methods to calculate, rather than directly measure, the PID from images of a single RBC, during either osmotic or pressure manipulation, were evaluated; the osmotic method closely predicted the PID, whereas the pressure method markedly underestimated the PID. Our results thus confirm the need to consider the above

  5. Mechanical stability of particle-stabilized droplets under micropipette aspiration

    NASA Astrophysics Data System (ADS)

    Samudrala, Niveditha; Nam, Jin; Sarfati, Raphaël; Style, Robert W.; Dufresne, Eric R.

    2017-01-01

    We investigate the mechanical behavior of particle-stabilized droplets using micropipette aspiration. We observe that droplets stabilized with amphiphilic dumbbell-shaped particles exhibit a two-stage response to increasing suction pressure. Droplets first drip, then wrinkle and buckle like an elastic shell. While particles have a dramatic impact on the mechanism of failure, the mechanical strength of the droplets is only modestly increased. On the other hand, droplets coated with the molecular surfactant sodium dodecyl sulfate are even weaker than bare droplets. In all cases, the magnitude of the critical pressure for the onset of instabilities is set by the fluid surface tension.

  6. Aspiration pneumonia and death in Huntington’s disease

    PubMed Central

    Heemskerk, Anne-Wil; Roos, Raymund A.C.

    2012-01-01

    Huntington’s disease (HD) is a progressive neurodegenerative autosomal dominant disease characterized by choreatic and hypokinetic movements, disturbed behaviour, and cognitive decline. Pneumonia is the most common cause of death, followed by cardiovasculair diseases. It has been suggested that choking is the causative underlying factor for pneumonia in HD. As a detailed specification of the type of pneumonia has never been performed, we analyzed the records of our Brain Bank containing 224 cases to determine the exact cause of death and type of pneumonia. The conclusion is that the majority (86.8%) of our HD patients where the cause of death could be identified died from aspiration pneumonia. PMID:22307361

  7. Ductal lavage, nipple aspiration, and ductoscopy for breast cancer diagnosis.

    PubMed

    Dooley, William C

    2003-01-01

    The intraductal approach to breast cancer has been invigorated this year by a series of papers exploring ductal-based screening through nipple aspiration and lavage and ductal exploration through endoscopy. The merging of these efforts to define the earliest biologic changes in the progression toward breast cancer is opening new fields for both bench-translational and clinical research. These techniques have already begun to show value in defining the presence and extent of proliferative disease in high-risk patients, allowing for more informed therapeutic decision making.

  8. Aspirated safety pin requiring thoracotomy: report of a case and review.

    PubMed

    Causey, A L; Talton, D S; Miller, R C; Warren, E T

    1997-12-01

    Foreign body aspirations in children are relatively uncommon occurrences, but they can be a serious events, causing respiratory distress, atelectasis, chronic pulmonary infections, or death. Safety pins are not commonly aspirated objects and account for less than 3% of all foreign bodies found in the tracheobronchial tree. Fewer than 2% of patients require thoracotomy, and most aspirated materials can be removed by bronchoscopy, with low morbidity and mortality. A discussion of airway foreign bodies follows the presentation of a case of an older child who aspirated a safety pin, which required open thoracostomy for removal.

  9. North American Summit on Aspiration in the Critically Ill Patient: consensus statement.

    PubMed

    McClave, Stephen A; DeMeo, Mark T; DeLegge, Mark H; DiSario, James A; Heyland, Daren K; Maloney, James P; Metheny, Norma A; Moore, Frederick A; Scolapio, James S; Spain, David A; Zaloga, Gary P

    2002-01-01

    Aspiration is the leading cause of pneumonia in the intensive care unit and the most serious complication of enteral tube feeding (ETF). Although aspiration is common, the clinical consequences are variable because of differences in nature of the aspirated material and individual host responses. A number of defense mechanisms normally present in the upper aerodigestive system that protect against aspiration become compromised by clinical events that occur frequently in the critical care setting, subjecting the patient to increased risk. The true incidence of aspiration has been difficult to determine in the past because of vague definitions, poor assessment monitors, and varying levels of clinical recognition. Standardization of terminology is an important step in helping to define the problem, design appropriate research studies, and develop strategies to reduce risk. Traditional clinical monitors of glucose oxidase strips and blue food coloring (BFC) should no longer be used. A modified approach to use of gastric residual volumes and identification of clinical factors that predispose to aspiration allow for risk stratification and an algorhythm approach to the management of the critically ill patient on ETF. Although the patient with confirmed aspiration should be monitored for clinical consequences and receive supportive pulmonary care, ETF may be continued when accompanied by appropriate steps to reduce risk of further aspiration. Management strategies for treating aspiration pneumonia are based on degree of diagnostic certainty, time of onset, and host factors.

  10. Immunocytochemical detection of milk proteins in tracheal aspirates of ventilated infants: a pilot study.

    PubMed

    Miller, Jamey; Colasurdo, Giuseppe N; Khan, Amir M; Jajoo, Charu; Patel, Tarak J; Fan, Leland L; Elidemir, Okan

    2002-11-01

    In this study, we evaluated immunocytochemical staining for milk proteins (alpha-lactalbumin and beta-lactoglobulin) in tracheal aspirates of mechanically ventilated infants, and assessed whether this staining technique supported a clinical diagnosis of aspiration in infants receiving orogastric feedings. All newborns requiring mechanical ventilation in the neonatal intensive care unit of a major tertiary care hospital were potential subjects for this study. Tracheal aspirates were obtained prior to the introduction of enteral feeding and at various time points thereafter in newborns requiring mechanical ventilation. Cells were obtained and processed for immunocytochemical staining of alpha-lactalbumin and beta-lactoglobulin. In total, 88 specimens recovered from 34 infants were adequate for staining. Alveolar macrophages recovered from most of the infants who were never fed (true negative controls) did not display immunoreactivity for milk proteins: 4/34 or 12% of infants' aspirates demonstrated presence of milk proteins before enteral feeding was commenced. Tracheal aspirates obtained from 12 infants after introduction of enteral feedings appeared to support clinical and radiological findings suggestive of aspiration events, with positive immunostaining on several occasions. These observations support our work in a murine model and demonstrate that immunocytochemical staining of tracheal aspirates for milk proteins may enhance the ability to diagnose pulmonary aspiration. Further studies are needed to define the clinical significance of our findings and the effects of single and repeated aspiration events on respiratory status.

  11. The natural history and clinical consequences of aspiration in acute stroke.

    PubMed

    Kidd, D; Lawson, J; Nesbitt, R; MacMahon, J

    1995-06-01

    Sixty consecutive patients admitted to a teaching hospital with acute stroke were studied prospectively for 3 months to define the natural history and consequences of lung aspiration. Using videofluoroscopy, aspiration was identified in 25 patients (42%) within 72 h of stroke onset, and had resolved in all but three patients (8%) after 3 months. It was closely related to the presence of dysphagia, which itself resolved within 2 weeks in all but the persistent aspirators. Lower respiratory tract infection (LRTI) was more common in aspirating patients (68%) than non-aspirators (6%). The use of intravenous fluids without oral intake did not appear to prevent LRTI in aspirating patients who were also dysphagic. Pneumonia occurred after 2 weeks in the three patients subsequently found to aspirate persistently. Aspiration is a transient phenomenon in most cases of acute stroke; it is associated with a high incidence of LRTI, but mortality in this series was not significantly associated either with respiratory tract infection or aspiration itself.

  12. Effectiveness of milrinone for cardiogenic shock due to massive pulmonary aspiration: a case report

    PubMed Central

    Park, Jeong Heon; Kim, Dong Hee; Kim, Seok-Kon; Jeon, Dae Geun; Song, Jaegyok; Ji, Seung Heon; Lee, Gwan Woo; Kang, Bong Jin

    2014-01-01

    Pulmonary aspiration of gastric contents is one of the most frightening complications during anesthesia. Although pulmonary aspiration of gastric contents in general surgical patients is not common and resulting long-term morbidity and mortality are rare, severe hypoxemia and other sequelae of pulmonary aspiration continue to be reported. We report a case of massive aspiration of gastric contents during induction of general anesthesia, resulting in cardiac arrest due to severe pulmonary hypertension and myocardial infarction. Sustained cardiac arrest and shock that did not respond the conventional resuscitation was successfully treated using milrinone. The patient was discharged without complications in 20 days. PMID:25006374

  13. Yield optimisation and molecular characterisation of uncultured CD271+ mesenchymal stem cells in the Reamer Irrigator Aspirator waste bag.

    PubMed

    Churchman, Sarah M; Kouroupis, Dimitrios; Boxall, Sally A; Roshdy, Tarek; Tan, Hiang B; McGonagle, Dennis; Giannoudis, Peter V; Jones, Elena A

    2013-12-13

    Bone reconstruction requires the use of autografts from patients' iliac crest (IC); for large-volume defects bone void fillers and autologous mesenchymal stem cells (MSCs) are often added. The Reamer/Irrigator/Aspirator (RIA) device provides the means of harvesting large amounts of autograft and additionally yields a waste bag containing MSCs, which is currently discarded. The aim of this study was to enumerate and characterise native MSCs from RIA waste bag and compare them to 'gold-standard' donor-matched MSCs from IC bone marrow (BM). IC-BM from age matched trauma patients was used as control. In RIA waste bags the median MSC yield established using a colony-forming fibroblast assay was 314333 (range 5 x 104-1.4 x 106), equivalent to approximately one litre of IC-BM aspirate. CD271+ cells were present at high levels in RIA waste bags, had MSC surface phenotype (CD90+CD73+CD105+CD34>sup>-CD61-CD19-CD31-CD33-) and expressed genes associated with multipotentiality, osteogenesis, adipogenesis and angiogenic support. RIA- CD271+ MSCs were transcriptionally similar to donor-matched IC-CD271+ MSCs (76 % transcripts); with the majority of bone-related and Wnt pathway molecules being expressed at comparable levels. Lower-level expression of MCAM/CD146 and 5/13 hypoxia-related molecules was found in RIA-CD271+ MSCs, potentially reflecting their native residence in a more hypoxic environment of the endosteum and bone cortex. These data suggest that long bones contain very large numbers of MSCs, transcriptionally-similar to IC-BM MSCs; they can be procured by reaming using the RIA device and used, following concentration, as autologous and potentially allogeneic bone repair therapy.

  14. Spheres of Influence: What Shapes Young People's Aspirations at Age 12/13 and What Are the Implications for Education Policy?

    ERIC Educational Resources Information Center

    Archer, Louise; DeWitt, Jennifer; Wong, Billy

    2014-01-01

    Young people's aspirations remain an enduring focus of education policy interest and concern. Drawing on data from an ongoing five-year study of young people's science and career aspirations (age 10-14), this paper asks what do young people aspire to at age 12/13, and what influences these aspirations? It outlines the main aspirations and sources…

  15. Aspiring to leadership--identifying teacher-leaders.

    PubMed

    Rogers, John

    2005-11-01

    Educational institutions need effective leaders at many levels. This paper explores the applicability of the Porter/Mazlow need-priority and Herzberg maintenance-motivation models to the challenge of identifying individuals who aspire to leadership. The review includes literature from teaching, engineering, medicine, astronomy, business, and the military. Autonomy need and achievement motivation consistently distinguished leaders from non-leaders in several studies. Affiliation and esteem needs also characterized leaders in two studies. These empirical data support the use of these theoretical models, which are intuitively appealing and have potential for practical applications. One such application could be the identification and recruitment of education "champions" who would be teacher-leaders at dispersed sites. Through self-reflection faculty members could become aware of their needs and motivations and may realize their leadership aspirations and accept the teacher-leader role. For an education "champions" program to be successful, the department leadership would need to attend to the organizational culture and provide release time for the teacher-leaders. A blueprint for the development of teacher-leaders is outlined.

  16. Gluteal Compartment Syndrome following an Iliac Bone Marrow Aspiration

    PubMed Central

    Vega-Najera, Carlos; Leal-Contreras, Carlos; Leal-Berumen, Irene

    2013-01-01

    The compartment syndrome is a condition characterized by a raised hydraulic pressure within a closed and non expandable anatomical space. It leads to a vascular insufficiency that becomes critical once the vascular flow cannot return the fluids back to the venous system. This causes a potential irreversible damage of the contents of the compartment, especially within the muscle tissues. Gluteal compartment syndrome (GCS) secondary to hematomas is seldom reported. Here we present a case of a 51-year-old patient with history of a non-Hodgkin lymphoma who underwent a bone marrow aspiration from the posterior iliac crest that had excessive bleeding at the puncture zone. The patient complained of increasing pain, tenderness, and buttock swelling. Intraoperative pressure validation of the gluteal compartment was performed, and a GCS was diagnosed. The patient was treated with a gluteal region fasciotomy. The patient recovered from pain and swelling and was discharged shortly after from the hospital. We believe clotting and hematologic disorders are a primary risk factor in patients who require bone marrow aspirations or biopsies. It is important to improve awareness of GCS in order to achieve early diagnosis, avoid complications, and have a better prognosis. PMID:24392235

  17. Meconium aspiration syndrome: possible pathophysiological mechanisms and future potential therapies.

    PubMed

    Lindenskov, Paal Helge Haakonsen; Castellheim, Albert; Saugstad, Ola Didrik; Mollnes, Tom Eirik

    2015-01-01

    Does meconium cause meconium aspiration syndrome (MAS) or is meconium discharge only a marker of fetal hypoxia? This dispute has lasted for centuries, but since the 1960s, detrimental effects of meconium itself on the lungs have been demonstrated in animal experiments. In clinical MAS, persistent pulmonary hypertension of the newborn is the leading cause of death in MAS. Regarding the complex chemical composition of meconium, it is difficult to identify a single agent responsible for the pathophysiology. However, considering that meconium is stored in the intestines, partly unexposed to the immune system, aspirated meconium could be recognized as ‘danger', representing damaged self. The common denominator in the pathophysiology could therefore be activation of innate immunity. Thus, a bulk of evidence implies that meconium is a potent activator of inflammatory mediators, including cytokines, complement, prostaglandins and reactive oxygen species. We hypothesize that the two main recognition systems of innate immunity, the Toll-like receptors and the complement system, recognize meconium as ‘danger', which leads not only to lung dysfunction but also to a systemic inflammatory response. This might have therapeutic implications in the future.

  18. Kinematics of red cell aspiration by fluorescence-imaged microdeformation.

    PubMed Central

    Discher, D E; Mohandas, N

    1996-01-01

    Maps of fluorescing red cell membrane components on a pipette-aspirated projection are quantitated in an effort to elucidate and unify the heterogeneous kinematics of deformation. Transient gradients of diffusing fluorescent lipid first demonstrate the fluidity of an otherwise uniform-density bilayer and corroborate a "universal" calibration scale for relative surface density. A steep but smooth and stable gradient in the densities of the skeleton components spectrin, actin, and protein 4.1 is used to estimate large elastic strains along the aspirated skeleton. The deformation fields are argued to be an unhindered response to loading in the surface normal direction. Density maps intermediate to those of the compressible skeleton and fluid bilayer are exhibited by particular transmembrane proteins (e.g., Band 3) and yield estimates for the skeleton-connected fractions. Such connected proteins appear to occupy a significant proportion of the undeformed membrane surface and can lead to steric exclusion of unconnected integral membrane proteins from regions of network condensation. Consistent with membrane repatterning kinematics in reversible deformation, final vesiculation of the projection tip produces a cell fragment concentrated in freely diffusing proteins but depleted of skeleton. Images FIGURE 1 FIGURE 2 FIGURE 4 FIGURE 5 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 PMID:8889146

  19. Mechanosensitive shivering of model tissues under controlled aspiration

    PubMed Central

    Guevorkian, Karine; Gonzalez-Rodriguez, David; Carlier, Camille; Dufour, Sylvie; Brochard-Wyart, Françoise

    2011-01-01

    During embryonic development and wound healing, the mechanical signals transmitted from cells to their neighbors induce tissue rearrangement and directional movements. It has been observed that forces exerted between cells in a developing tissue under stress are not always monotonically varying, but they can be pulsatile. Here we investigate the response of model tissues to controlled external stresses. Spherical cellular aggregates are subjected to one-dimensional stretching forces using micropipette aspiration. At large enough pressures, the aggregate flows smoothly inside the pipette. However, in a narrow range of moderate aspiration pressures, the aggregate responds by pulsed contractions or “shivering.” We explain the emergence of this shivering behavior by means of a simple analytical model where the uniaxially stretched cells are represented by a string of Kelvin–Voigt elements. Beyond a deformation threshold, cells contract and pull on neighboring cells after a time delay for cell response. Such an active behavior has previously been found to cause tissue pulsation during dorsal closure of Drosophila embryo. PMID:21771735

  20. A Patient With Aspiration Pneumonia After Mandibular Osteotomy With Genioplasty.

    PubMed

    Ohba, Seigo; Kawasaki, Takako; Hashimoto, Megumi; Yoshida, Noriaki; Ashina, Izumi

    2016-06-01

    Orthognathic surgery including maxillary osteotomy, mandibular osteotomy, and genioplasty is a reliable treatment strategy for jaw deformity. However, there are some complications associated with these surgeries, including neurovascular damage and abnormal bleeding. The authors present here a patient of aspiration pneumonia after mandibular osteotomy.An 18-year-old female patient underwent sagittal split ramus osteotomy and genioplasty for mandibular prognathism. She began choking and coughing immediately after surgery. She was diagnosed with aspiration pneumonia based on chest radiography and computed tomography findings. Her hyoid bone was shifted 23 mm inferiorly after surgery, and this movement may have caused swallowing dysfunction. She was treated with intravenous antibiotics and discharged on the 18th postoperative day.Although the hyoid bone is transiently shifted inferiorly by mandibular setback with or without genioplasty, this shift does not usually affect swallowing function. Damage to the suprahyoid muscles during genioplasty may cause both an inferior shift and dysmobility of the hyoid bone. Therefore, surgeons must be careful not to damage the suprahyoid muscles at the lingual site osteotomy in genioplasty to avoid this complication.

  1. 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.

  2. Aspiration pneumonia after concurrent chemoradiotherapy for head-and-neck cancer

    PubMed Central

    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.

    2016-01-01

    Background Aspiration pneumonia represents an under-reported complication of chemoradiotherapy in head-and-neck cancer. This study evaluated the incidence, risk factors, and mortality of aspiration pneumonia in a large cohort of head-and-neck cancer patients treated with concurrent chemoradiotherapy. Methods Patients with head-and-neck cancer diagnosed between 2000 and 2009 were identified from the SEER-Medicare database. Aspiration pneumonia was identified from Medicare billing claims. The cumulative incidence, risk factors, and survival after aspiration pneumonia were estimated and compared to a non-cancer population. Results Of 3,513 head-and-neck cancer patients, 801 patients developed aspiration pneumonia at a median time of 5 months after initiating treatment. The 1- and 5-year cumulative incidence of aspiration pneumonia was 15.8% and 23.8% for head-and-neck cancer patients and 3.6% and 8.7% for non-cancer controls, respectively. Among cancer patients multivariate analysis identified independent risk factors (p<0.05) for aspiration pneumonia including hypopharyngeal and nasopharyngeal tumors, male gender, older age, increased comorbidity, no surgery prior to radiation, and care received at a teaching hospital. Among cancer patients who experienced aspiration pneumonia, 674 (84%) were hospitalized of which 301 (45%) were admitted to an intensive care unit. Thirty-day mortality after hospitalization for aspiration pneumonia was 32.5%. Aspiration pneumonia was associated with a 42% increased risk of death (HR=1.42, p<0.001) after controlling for confounders. Conclusions This study found that nearly one-quarter of elderly patients will develop aspiration pneumonia within 5 years of chemoradiotherapy for head-and-neck cancer. A better understanding of mitigating factors will help identify patients at risk for this potentially lethal complication. PMID:25537836

  3. Phase precession and variable spatial scaling in a periodic attractor map model of medial entorhinal grid cells with realistic after-spike dynamics.

    PubMed

    Navratilova, Zaneta; Giocomo, Lisa M; Fellous, Jean-Marc; Hasselmo, Michael E; McNaughton, Bruce L

    2012-04-01

    We present a model that describes the generation of the spatial (grid fields) and temporal (phase precession) properties of medial entorhinal cortical (MEC) neurons by combining network and intrinsic cellular properties. The model incorporates network architecture derived from earlier attractor map models, and is implemented in 1D for simplicity. Periodic driving of conjunctive (position × head-direction) layer-III MEC cells at theta frequency with intensity proportional to the rat's speed, moves an 'activity bump' forward in network space at a corresponding speed. The addition of prolonged excitatory currents and simple after-spike dynamics resembling those observed in MEC stellate cells (for which new data are presented) accounts for both phase precession and the change in scale of grid fields along the dorso-ventral axis of MEC. Phase precession in the model depends on both synaptic connectivity and intrinsic currents, each of which drive neural spiking either during entry into, or during exit out of a grid field. Thus, the model predicts that the slope of phase precession changes between entry into and exit out of the field. The model also exhibits independent variation in grid spatial period and grid field size, which suggests possible experimental tests of the model.

  4. Multimap formation in visual cortex

    PubMed Central

    Jain, Rishabh; Millin, Rachel; Mel, Bartlett W.

    2015-01-01

    An extrastriate visual area such as V2 or V4 contains neurons selective for a multitude of complex shapes, all sharing a common topographic organization. Simultaneously developing multiple interdigitated maps—hereafter a “multimap”—is challenging in that neurons must compete to generate a diversity of response types locally, while cooperating with their dispersed same-type neighbors to achieve uniform visual field coverage for their response type at all orientations, scales, etc. Previously proposed map development schemes have relied on smooth spatial interaction functions to establish both topography and columnar organization, but by locally homogenizing cells' response properties, local smoothing mechanisms effectively rule out multimap formation. We found in computer simulations that the key requirements for multimap development are that neurons are enabled for plasticity only within highly active regions of cortex designated “learning eligibility regions” (LERs), but within an LER, each cell's learning rate is determined only by its activity level with no dependence on location. We show that a hybrid developmental rule that combines spatial and activity-dependent learning criteria in this way successfully produces multimaps when the input stream contains multiple distinct feature types, or in the degenerate case of a single feature type, produces a V1-like map with “salt-and-pepper” structure. Our results support the hypothesis that cortical maps containing a fine mixture of different response types, whether in monkey extrastriate cortex, mouse V1 or elsewhere in the cortex, rather than signaling a breakdown of map formation mechanisms at the fine scale, are a product of a generic cortical developmental scheme designed to map cells with a diversity of response properties across a shared topographic space. PMID:26641946

  5. Patterns of Spontaneous Local Network Activity in Developing Cerebral Cortex: Relationship to Adult Cognitive Function.

    PubMed

    Peinado, Alejandro; Abrams, Charles K

    2015-01-01

    Detecting neurodevelopμental disorders of cognition at the earliest possible stages could assist in understanding them mechanistically and ultimately in treating them. Finding early physiological predictors that could be visualized with functional neuroimaging would represent an important advance in this regard. We hypothesized that one potential source of physiological predictors is the spontaneous local network activity prominent during specific periods in development. To test this we used calcium imaging in brain slices and analyzed variations in the frequency and intensity of this early activity in one area, the entorhinal cortex (EC), in order to correlate early activity with level of cognitive function later in life. We focused on EC because of its known role in different types of cognitive processes and because it is an area where spontaneous activity is prominent during early postnatal development in rodent models of cortical development. Using rat strains (Long-Evans, Wistar, Sprague-Dawley and Brattleboro) known to differ in cognitive performance in adulthood we asked whether neonatal animals exhibit corresponding strain-related differences in EC spontaneous activity. Our results show significant differences in this activity between strains: compared to a high cognitive-performing strain, we consistently found an increase in frequency and decrease in intensity in neonates from three lower performing strains. Activity was most different in one strain considered a model of schizophrenia-like psychopathology. While we cannot necessarily infer a causal relationship between early activity and adult cognition our findings suggest that the pattern of spontaneous activity in development could be an early predictor of a developmental trajectory advancing toward sub-optimal cognitive performance in adulthood. Our results further suggest that the strength of dopaminergic signaling, by setting the balance between excitation and inhibition, is a potential underlying

  6. Rural Scholars or Bright Rednecks? Aspirations for a Sense of Place among Rural Youth in Appalachia.

    ERIC Educational Resources Information Center

    Howley, Craig; And Others

    This study compares the attitudes of academically gifted rural students with those of their classmates with regard to their communities and their aspirations for a sense of place. Although West Virginia, a largely rural state in Appalachia, is considered by outsiders as a place of deprivation, despair, and backwardness, an aspiration for a sense…

  7. 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…

  8. Creative Aspirations or Pipe Dreams? Toward Understanding Creative Mortification in Children and Adolescents

    ERIC Educational Resources Information Center

    Beghetto, Ronald A.; Dilley, Anna E.

    2016-01-01

    What experiences influence the development of creativity in children and adolescents? One experience is the mortification of creative aspirations. Creative mortification (CM) refers to the loss of one's willingness to pursue a particular creative aspiration following a negative performance outcome. The purpose of this article is to introduce an…

  9. Aspiration, Identity and Self Belief: Snapshots of Social Structure at Work

    ERIC Educational Resources Information Center

    Riddell, Richard, Ed.

    2010-01-01

    This book presents the evidence gathered from original interviews to show how the aspirations of young people develop in light of their social circumstances. Those who attend independent schools will find that the relationship between what goes on at home and at school makes it socially almost impossible not to have achievable aspirations for a…

  10. Independent School Department Heads: The Influence of Role Ambiguity, Relationships, and Professional Development on Career Aspirations

    ERIC Educational Resources Information Center

    Kinsella, Shane

    2012-01-01

    Little research exists on the career aspirations of department heads in independent schools. What does exist focuses on public school teachers in the United States and the United Kingdom. This study sought to determine the career aspirations, job satisfaction, and job efficacy of department heads. Using data from an original survey instrument…

  11. 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…

  12. 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,…

  13. Educational and Career Aspirations of Secondary School Students in Grenada Following the American Intervention.

    ERIC Educational Resources Information Center

    Chadwick, Bruce A.; Albrecht, Stan L.

    1989-01-01

    Examined educational and occupational aspirations of secondary school students in Grenada following 1983 American intervention. Questionnaire data from 729 students revealed that Grenadian students had exceptionally and unrealistically high aspirations. Opportunity structure in Grenada was found to be very limited compared to that in United…

  14. Parents' Aspirations for Their Children's Educational and Occupational Prospects in Greece: The Role of Social Class

    ERIC Educational Resources Information Center

    Vryonides, Marios; Gouvias, Dionysios

    2012-01-01

    This paper focuses on parents and the way they perceive and formulate expectations and aspirations about their children's educational and occupational outcomes. Drawing on evidence from a survey among more than 700 parents of primary school pupils this paper demonstrates that interesting patterns in parental aspirations can be observed. These…

  15. Motivation and Career Aspirations of Female Students Studying Science at Achimota School in Accra, Ghana

    ERIC Educational Resources Information Center

    Andoh, Paul K.; Bosiakoh, Thomas Antwi; Afranie, Stephen

    2012-01-01

    This paper examines science education for girls in Achimota School, a second cycle institution in Accra, in terms of their motivations for pursuing science and future aspirations. It explores parental backgrounds and how they impacted on the motivations and aspirations of the girls. The survey method was adopted in this study, which involved a…

  16. The Relationship between Career Variables and Occupational Aspirations and Expectations for Australian High School Adolescents

    ERIC Educational Resources Information Center

    Patton, Wendy; Creed, Peter

    2007-01-01

    This study surveyed 925 Australian high school students enrolled in grades 8 through 12 on measures of occupational aspirations, occupational expectations, career status aspirations, and career status expectations; it tested the association between these variables and career maturity, career indecision, career decision-making self-efficacy, and…

  17. The Effects on Motor Performance of Setting an Overt Level of Aspiration by Mentally Retarded Students.

    ERIC Educational Resources Information Center

    Kozar, Bill

    This study investigates the effects of setting an overt level of aspiration on the standing long jump performance of mildly and moderately retarded institutionalized children. Thirty-three mildly retarded and seven moderately retarded students were randomly assigned to either an overt level of aspiration (OLA) group or a control group. Each…

  18. Developing Conceptual Understandings of the Capacity to Aspire for Higher Education

    ERIC Educational Resources Information Center

    Prodonovich, Samuel; Perry, Laura B.; Taggart, Andrew

    2014-01-01

    This paper reviews research and theory relating to aspirations for higher education as a cultural capacity. Understanding the social and cultural dimensions of aspirations for higher education is important as they are increasingly becoming part of social commentary and more recently educational policy, research and practice. This paper synthesises…

  19. Project ASPIRE: Assisting Special Populations in Readiness for Employment. A California Work Ability Project.

    ERIC Educational Resources Information Center

    Butler, Marsha L.

    ASPIRE--"Assisting Special Populations in Readiness for Employment"--is a secondary special education transition program featuring coordinated services between the public and private sectors to integrate secondary level disabled students into subsidized private sector employment. ASPIRE was introduced into the Lake Tahoe Unified School…

  20. Aspiring Principals' Perception of the Challenges of Beginning Principals and the Support That They Need

    ERIC Educational Resources Information Center

    Ng, Pak Tee

    2015-01-01

    This paper presents the results of an exploratory research project about the perception of aspiring principals regarding the challenges of beginning principals and the support that they need. These aspiring principals are participants on the Leaders in Education Programme (LEP) in Singapore. According to the research findings, the LEP participants…