Jj. Wagner et Be. Alger, INCREASED NEURONAL EXCITABILITY DURING DEPOLARIZATION-INDUCED SUPPRESSION OF INHIBITION IN RAT HIPPOCAMPUS, Journal of physiology, 495(1), 1996, pp. 107-112
1. Depolarization-induced suppression of inhibition (DSI) is a form of
plasticity of gamma-aminobutyric acid (GABA(A))-mediated (henceforth
'GABAergic') responses in the CNS. We made whole-cell recordings from
CA1 pyramidal neurons to investigate the effects of DSI on excitatory
synaptic transmission in the hippocampal slice preparation. 2. Signifi
cant enhancement of the voltage-clamped excitatory postsynaptic curren
t (EPSC) occurs during DSI of the temporally overlapping inhibitory po
stsynaptic current. Viiith high levels of calcium chelators in the pip
ette solution, or bath application of bicuculline, EPSC enhancement is
blocked, suggesting that it results from DSI and that the DSI process
selectively affects GABAergic, but not glutamatergic, transmission. 3
. The probability of synaptically evoked action potential firing is in
creased during DSI under current clamp. DSI could influence other exci
tatory phenomena as well.