AUTHOR=Valeeva Guzel , Abdullin Azat , Tyzio Roman , Skorinkin Andrei , Nikolski Evgeny , Ben-Ari Yehezkiel , Khazipov Rustem TITLE=Temporal Coding at the Immature Depolarizing GABAergic Synapse JOURNAL=Frontiers in Cellular Neuroscience VOLUME=Volume 4 - 2010 YEAR=2010 URL=https://www.frontiersin.org/journals/cellular-neuroscience/articles/10.3389/fncel.2010.00017 DOI=10.3389/fncel.2010.00017 ISSN=1662-5102 ABSTRACT=
In the developing hippocampus, GABA exerts depolarizing and excitatory actions and contributes to the generation of neuronal network driven giant depolarizing potentials (GDPs). Here, we studied spike time coding at immature GABAergic synapses and its impact on synchronization of the neuronal network during GDPs in the neonatal (postnatal days P2–6) rat hippocampal slices. Using extracellular recordings, we found that the delays of action potentials (APs) evoked by synaptic activation of GABA(A) receptors are long (mean, 65 ms) and variable (within a time window of 10–200 ms). During patch-clamp recordings, depolarizing GABAergic responses were mainly subthreshold and their amplification by persistent sodium conductance was required to trigger APs. AP delays at GABAergic synapses shortened and their variability reduced with an increase in intracellular chloride concentration during whole-cell recordings. Negative shift of the GABA reversal potential (