gamma-Aminobutyrate sensitivity does not change during long-term potentiation in rat hippocampal slices.
Long-term potentiation is a long-lasting enhancement of synaptic efficacy following brief, high-frequency, repetitive stimulation of a monosynaptic input. Intracellular recordings have shown that the inhibitory postsynaptic potential changes in amplitude during long-term potentiation. Yet how this may occur is unclear. To test for a possible alteration in postsynaptic sensitivity to the recurrent inhibitory transmitter gamma-aminobutyrate, we have examined the effect of gamma-aminobutyrate, focally applied to the hippocampal CA1 cell-body layer, on the extracellular recorded action potential (population spike). We found that the degree, duration, dose-dependence and time-course of inhibition produced by gamma-aminobutyrate are unchanged during long-term potentiation. This suggests that a change in sensitivity of CA1 pyramidal cells to the transmitter gamma-aminobutyrate is not the reason for the alteration in the inhibitory postsynaptic potential during long-term potentiation.
D000818:Animals; D005071:Evoked Potentials; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D005680:gamma-Aminobutyric Acid