Abstract

Summary: The timing of the developmental switch in the GABA A mediated responses from excitatory to inhibitory was studied in Wistar rat CA3 hippocampal pyramidal cells using gramicidin perforated patch‐clamp and extracellular recordings. Gramicidin perforated patch recordings revealed a gradual developmental shift in the reversal potential of synaptic and isoguvacine‐induced GABA A mediated responses from –55 ± 4 mV at postnatal days P0–2 to −74 ± 3 mV at P13–15 with a midpoint of disappearance of the excitatory effects of GABA at around P8. Extracellular recordings in CA3 pyramidal cell layer revealed that the effect of isoguvacine on multiple unit activity (MUA) switched from an increase to a decrease at around P10. The effect of synaptic GABA A mediated responses on MUA switched from an increase to a decrease at around P8. It is concluded that the developmental switch in the action of GABA via GABA A receptors from excitatory to inhibitory occurs in Wistar rat CA3 pyramidal cells at around P8–10, an age that coincides with the transition from immature to mature hippocampal rhythms. We propose that excitatory GABA contributes to enhanced excitability and ictogenesis in the neonatal rat hippocampus.

Keywords

Excitatory postsynaptic potentialInhibitory postsynaptic potentialHippocampal formationNeurosciencePyramidal cellHippocampusExtracellularGABAA receptorBiologyElectrophysiologyNeurotransmissionPatch clampChemistryReceptorCell biologyBiochemistry

MeSH Terms

Action PotentialsAge FactorsAnimalsAnimalsNewbornBicucullineCalcium ChannelsElectrophysiologyExcitatory Postsynaptic PotentialsFemaleGABA-A Receptor AntagonistsGramicidinHippocampusInhibitory Postsynaptic PotentialsIsonicotinic AcidsMalePatch-Clamp TechniquesPyramidal CellsRatsRatsWistarReceptorsGABA-Agamma-Aminobutyric Acid

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Publication Info

Year
2007
Type
article
Volume
48
Issue
s5
Pages
96-105
Citations
165
Access
Closed

Citation Metrics

165
OpenAlex
8
Influential
143
CrossRef

Cite This

Roman Tyzio, Gregory L. Holmes, Yehezkel Ben‐Ari et al. (2007). Timing of the Developmental Switch in GABA<sub>A</sub> Mediated Signaling from Excitation to Inhibition in CA3 Rat Hippocampus Using Gramicidin Perforated Patch and Extracellular Recordings. Epilepsia , 48 (s5) , 96-105. https://doi.org/10.1111/j.1528-1167.2007.01295.x

Identifiers

DOI
10.1111/j.1528-1167.2007.01295.x
PMID
17910587

Data Quality

Data completeness: 86%