Abstract:
:Ontogenesis of GABAergic signaling may play an important role in developmental changes in seizure susceptibility in the high-potassium model of ictogenesis in vitro. The age-dependent effects of [K(+)](o) on the reversal potential of the GABA(A)-mediated responses and membrane potential in hippocampal slices in vitro were compared with the effect of GABA(A)-receptors antagonists and GABA(A) modulators on high-potassium induced seizures in the CA3 pyramidal layer of rat hippocampus in vivo. GABA(A) responses were depolarizing at P8-12 and hyperpolarizing at P17-21. In P8-12 rats, GABA(A) responses switch their polarity from depolarizing to hyperpolarizing upon elevation of extracellular potassium. At approximately 10 mM [K(+)](o), activation of GABA(A) receptors produced an isoelectric, purely shunting response characterized by no changes in the membrane potential but an increase in the membrane conductance. In P17-21 rats, the hyperpolarizing GABA(A) driving force progressively increased with elevation of [K(+)](o). In P8-12 rats in vivo, GABA(A)-receptor antagonists did not affect the occurrence of ictal discharges induced by intrahippocampal injection of 10 mM [K(+)](o), but significantly increased seizure duration. Diazepam and isoguvacine completely prevented seizures induced by 10 mM [K(+)](o). In P17-21 rats, GABA(A)-receptor antagonists strongly increased the occurrence of ictal activity induced both by 10 mM [K(+)](o). Taken together, these results suggest that anticonvulsive effects of GABA are because of the combination of shunting and hyperpolarizing actions of GABA. Although shunting GABA is already efficient in the young age group, a developmental increase in the hyperpolarizing GABA(A) driving force likely contributes to the increase in the GABAergic control of seizures upon maturation.
journal_name
Hippocampusjournal_title
Hippocampusauthors
Isaev D,Isaeva E,Khazipov R,Holmes GLdoi
10.1002/hipo.20259subject
Has Abstractpub_date
2007-01-01 00:00:00pages
210-9issue
3eissn
1050-9631issn
1098-1063journal_volume
17pub_type
杂志文章相关文献
HIPPOCAMPUS文献大全abstract::Previous work has shown that immunohistochemical imaging of Fos protein is a reliable marker for changes in activity related to recognition memory in the perirhinal (PRH) cortex of the medial temporal lobe; however, whether PRH Fos expression is necessary for recognition memory had not been established. To investigate...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22028
更新日期:2012-11-01 00:00:00
abstract::During certain movements (termed "type I," "instrumental," or "voluntary"), the rodent hippocampal EEG is dominated by regular 7-10 Hz waves. This "theta rhythm" is accompanied by increased firing of hippocampal interneurons and dentate gyrus granule cells. No obvious theta rhythm is present in comparable situations i...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.450010204
更新日期:1991-04-01 00:00:00
abstract::Gelsolin is an actin-binding protein that regulates actin filament-severing and capping activity in the various processes of cell motilities. Here, we report the expression of gelsolin mRNA and protein in the hippocampus following transections of the entorhinal afferents. Northern blot analysis showed that transcript ...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20134
更新日期:2006-01-01 00:00:00
abstract::The present study has investigated the role of ATP in the induction of synaptic plasticity, using local application of ATP by picopump administration into the stratum radiatum of guinea pig hippocampal region CA1. Excitatory postsynaptic currents (EPSCs) evoked by stimulation of Schaffer collateral/commissural afferen...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.7999
更新日期:2003-01-01 00:00:00
abstract::The role of perforant pathway-dentate granule cell synapses in cognitive behavior was examined focusing on synaptic Zn(2+) signaling in the dentate gyrus. Object recognition memory was transiently impaired when extracellular Zn(2+) levels were decreased by injection of clioquinol and N,N,N',N'-tetrakis-(2-pyridylmethy...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22322
更新日期:2014-11-01 00:00:00
abstract::In this study the subcortical afferents for the rat PER areas 35 and 36, POR, and the lateral and medial entorhinal areas (LEA and MEA) were characterized. We analyzed 33 retrograde tract-tracing experiments distributed across the five regions. For each experiment, we estimated the total numbers, percentages, and dens...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22603
更新日期:2016-09-01 00:00:00
abstract::Norepinephrine, is involved in the enhancement of learning and memory formation by regulating synaptic mechanisms through its ability to activate pre- and post-synaptic adrenergic receptors. Here we show that β-agonists of norepinephrine facilitate the induction of both associational LTP and sharp wave ripples (SPW-Rs...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22665
更新日期:2016-12-01 00:00:00
abstract::We recorded neuromagnetic fields evoked by a somatosensory oddball task requiring subjects to discriminate target stimuli from nontarget stimuli, which are different in stimulation intensity, with a mental count of the target stimuli. A whole head type 80-channel magnetoencephalography (MEG) system with a 50-mm baseli...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.10196
更新日期:2004-01-01 00:00:00
abstract::Once thought to produce global, nonspecific brain injury, drugs of abuse are now known to produce selective neuro-adaptations in particular brain regions. These neuro-adaptations are being closely examined for clues to the development, maintenance, and treatment of addiction. The hippocampus is an area of particular i...
journal_title:Hippocampus
pub_type: 杂志文章,评审
doi:10.1002/hipo.20161
更新日期:2006-01-01 00:00:00
abstract::Although it is well established that the integrity of the medial temporal lobe (MTL) is critical for declarative memory, the functional organization of the MTL remains a matter of intense debate. One issue that has received little consideration so far is whether the hippocampus can function normally in the presence of...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20800
更新日期:2011-08-01 00:00:00
abstract::It is well documented that place cells and grid cells in echolocating bats show properties similar to those described in rodents, and yet, continuous theta-frequency oscillations, proposed to play a central role in grid/place cell formation, are not present in bat recordings. These comparative neurophysiological data ...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22469
更新日期:2015-12-01 00:00:00
abstract::Rats were trained on an operant conditional discrimination in which an ambiguous stimulus (X) indicated both the occasions on which responding in the presence of a second cue (A) would be reinforced and the occasions on which responding in the presence of a third cue (B) would not be reinforced (X --> A+, A-, X --> B-...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/(SICI)1098-1063(1998)8:2<138::AID-HIPO6>3.
更新日期:1998-01-01 00:00:00
abstract::In all species examined, the dentate gyrus develops over an extended period that begins during gestation and continues up to adulthood. The aim of this study was to investigate the pattern of postnatal cell production in the dentate gyrus of the guinea pig, a rodent whose brain development has features more closely re...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20050
更新日期:2005-01-01 00:00:00
abstract::Neural correlates of spatial representation can be found in the activity of the hippocampal place cells. These neurons are characterized by firing whenever the animal is located in a particular area of the space, the place field. Place fields are modulated by sensory cues, such as visual, auditory, or olfactory cues, ...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22198
更新日期:2013-12-01 00:00:00
abstract::Aging is associated with an impaired ability to maintain long-term potentiation (LTP), but the underlying cause of the impairment remains unclear. To gain a better understanding of the cellular and molecular mechanisms responsible for this impairment, the synaptic transmission and plasticity were studied in the CA1 re...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.10032
更新日期:2002-01-01 00:00:00
abstract::The advent of high-resolution magnetic resonance imaging (MRI) has enabled in vivo research in a variety of populations and diseases on the structure and function of hippocampal subfields and subdivisions of the parahippocampal gyrus. Because of the many extant and highly discrepant segmentation protocols, comparing r...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22671
更新日期:2017-01-01 00:00:00
abstract::Fear can be extinguished by repeated exposure to a cue that signals threat. However, extinction does not erase fear, as an extinguished cue presented in a context distinct from that of extinction results in renewed fear of that cue. The hippocampus, which is involved in the formation of contextual representations, is ...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20954
更新日期:2012-05-01 00:00:00
abstract::Neuregulins (NRGs) are ligands of ErbB receptor tyrosine kinases. The NRG1-ErbB4 pathway has been shown to modulate hippocampal synaptic plasticity and network oscillations in the adult rodent brain. To identify cells that mediate these effects, here we determine the expression pattern of ErbB4 in four functionally di...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20675
更新日期:2010-06-01 00:00:00
abstract::In this article, we present a framework to perform statistical shape analysis for segmented hippocampi, including an efficient permutation test for detecting subtle class differences, and a regularized discriminative direction method for visualizing the shape discrepancy. Fisher permutation and bootstrap tests are pre...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20639
更新日期:2009-06-01 00:00:00
abstract::In this review, we aim to reappraise the organization of intrinsic and extrinsic networks of the entorhinal cortex with a focus on the concept of parallel cortical connectivity streams. The concept of two entorhinal areas, the lateral and medial entorhinal cortex, belonging to two parallel input-output streams mediati...
journal_title:Hippocampus
pub_type: 杂志文章,评审
doi:10.1002/hipo.23145
更新日期:2019-12-01 00:00:00
abstract::The mechanisms underlying memory are under intense investigation. One of the most promising candidates at the cellular level is long-term potentiation (LTP). Numerous pharmacological and molecular genetic manipulations have led to alteration in both LTP and memory. However, the causal relationship between these phenot...
journal_title:Hippocampus
pub_type: 杂志文章,评审
doi:10.1002/hipo.10101
更新日期:2002-01-01 00:00:00
abstract::Episodic memory improves during childhood and this improvement has been associated with age differences in hippocampal function, but previous research has not manipulated the possible underlying mechanisms. We tested the hypothesis that age-related differences in hippocampal activation may reflect changes in retrieval...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.22538
更新日期:2016-04-01 00:00:00
abstract::Changes in the spatial arrangement or identity of objects inside a familiar environment induce reexploration. The present study looks at modifications of place cell activity during such renewed exploration. Hungry rats foraged for food in a cylinder with a salient cue card attached to the wall and with two distinct ob...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20060
更新日期:2005-01-01 00:00:00
abstract::Neuronal mechanisms of episodic memory, the conscious recollection of autobiographical events, are largely unknown because electrophysiological studies in humans are conducted only in exceptional circumstances. Unit recording studies in animals are thus crucial for understanding the neurophysiological substrate that e...
journal_title:Hippocampus
pub_type: 杂志文章,评审
doi:10.1002/hipo.20204
更新日期:2006-01-01 00:00:00
abstract::Previous attempts to elucidate whether a loss of hippocampal synapses occurs during aging provided conflicting results, possibly due to the unavailability, at the time, of unbiased methods for synapse quantitation. This study was designed to reexamine the issue by means of modern technical procedures that provide unbi...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.450020411
更新日期:1992-10-01 00:00:00
abstract::Adult neurogenesis continues throughout life in the mammalian hippocampus. The precise function of the adult generated neurons remains uncertain although there is growing evidence that they are involved in hippocampus-dependent learning and memory. Training rats on a hidden platform version of the Morris water task ha...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20692
更新日期:2010-07-01 00:00:00
abstract::Two experiments assessed the effects of 1) combined subicular complex and posterior cingulate cortical lesions on training-induced neuronal activity (TIA) in the anterior ventral (AV) and medial dorsal (MD) thalamic nuclei; 2) hippocampal (Ammon's horn and dentate gyrus) lesions on TIA in cingulate cortex and in the A...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/(SICI)1098-1063(1998)8:5<491::AID-HIPO8>3.
更新日期:1998-01-01 00:00:00
abstract::The present study evaluated the effects of a single intrahippocampal administration of brain-derived neurotrophic factor (BDNF) on memory retention in a water maze. Adult rats were trained in a water maze (acquisition phase, day 1). Immediately after the last training trial subjects were injected in the right hippocam...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.10220
更新日期:2004-01-01 00:00:00
abstract::Persistent neural activity lasting for seconds after transient stimulation has been observed in several brain areas. This activity has been taken to be indicative of the integration of inputs on long time scales. Passive membrane properties render neural time constants to be on the order of milliseconds. Intense synap...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.20112
更新日期:2005-01-01 00:00:00
abstract::To minimize the variability in the extent of lesions made by injections of the excitotoxin ibotenic acid in rhesus monkeys, we developed and validated an MRI-based method to determine the efficacy of the injections soon after surgery. T2-weighted MR images were obtained 6-11 days after surgery from 17 brain hemisphere...
journal_title:Hippocampus
pub_type: 杂志文章
doi:10.1002/hipo.1050
更新日期:2001-01-01 00:00:00