Linked Life Data

15961234

Source:http://linkedlifedata.com/resource/pubmed/id/15961234

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-7-11
pubmed:abstractText
The local circuitry of the mammalian limbic cortices, including the hippocampus, is capable of generating spontaneous rhythmic activities of 0.5-4 Hz when isolated in vitro. These rhythmic activities are mediated by synchronous inhibitory postsynaptic potentials in pyramidal neurons as the result of repeated discharges of inhibitory interneurons. As such, they are thought to represent an intrinsic inhibitory rhythm. It is unknown at present whether such a rhythm occurs in the immature rodent hippocampus and, if so, the postnatal time window in which it develops. We explored these issues using our recently developed whole mouse hippocampal isolate preparation in vitro. We found that spontaneous rhythmic field potentials started to emerge in mouse hippocampal isolates around postnatal day 10, stabilized after postnatal day 15 and persisted into adulthood. In postnatal days 11-14 mouse hippocampi, the properties of these rhythmic potentials were in keeping with a CA3-driven, IPSP-based intrinsic network activity. The lack of spontaneous field rhythm in neonatal (postnatal days 2-7) hippocampi cannot be attributed to the excitatory activities mediated by gamma-aminobutyric acid type A (GABA-A) receptors, as chloride-dependent hyperpolarizing inhibitory postsynaptic potentials were detectable in neonatal pyramidal neurons at voltages near resting potentials and pharmacological antagonisms of GABA-A receptors produced robust epileptiform discharges in neonatal hippocampi. High frequency afferent stimulation or applications of 4-aminopyridine at low micromolar concentrations failed to induce persistent field rhythm in neonatal hippocampi, suggesting that an overall weak glutamatergic drive is not the sole causing factor. We suggest that the inhibitory postsynaptic potential-based spontaneous rhythmic field potentials develop in a discrete time window during the second postnatal week in the mouse hippocampus due to a fine-tuning in the structure and function of CA3 recurrent circuitry and associated GABAergic inhibitory interneurons.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0306-4522
pubmed:author
pubmed:issnType
Print
pubmed:volume
134
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
107-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:15961234-2-Amino-5-phosphonovalerate, pubmed-meshheading:15961234-4-Aminopyridine, pubmed-meshheading:15961234-6-Cyano-7-nitroquinoxaline-2,3-dione, pubmed-meshheading:15961234-Action Potentials, pubmed-meshheading:15961234-Age Factors, pubmed-meshheading:15961234-Animals, pubmed-meshheading:15961234-Animals, Newborn, pubmed-meshheading:15961234-Bicuculline, pubmed-meshheading:15961234-Dose-Response Relationship, Radiation, pubmed-meshheading:15961234-Drug Interactions, pubmed-meshheading:15961234-Electric Stimulation, pubmed-meshheading:15961234-Excitatory Amino Acid Antagonists, pubmed-meshheading:15961234-Excitatory Postsynaptic Potentials, pubmed-meshheading:15961234-GABA Antagonists, pubmed-meshheading:15961234-Hippocampus, pubmed-meshheading:15961234-Mice, pubmed-meshheading:15961234-Mice, Inbred C57BL, pubmed-meshheading:15961234-Neurons, pubmed-meshheading:15961234-Patch-Clamp Techniques, pubmed-meshheading:15961234-Periodicity, pubmed-meshheading:15961234-Potassium Channel Blockers, pubmed-meshheading:15961234-gamma-Aminobutyric Acid
pubmed:year
2005
pubmed:articleTitle
Postnatal development of intrinsic GABAergic rhythms in mouse hippocampus.
pubmed:affiliation
Toronto Western Research Institute, University of Toronto, Canada.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't