The role of inhibitory mechanisms in hippocampal long-term potentiation.

The role of inhibitory processes in long-term potentiation (LTP) was investigated in hippocampal slices of the rat. GABAergic inhibition, tested by double shock experiments and by intracellular recording of inhibitory postsynaptic potentials, was not reduced in CA 1 pyramidal neurones after the induction of LTP. In cells recorded with caesium chloride-filled electrodes LTP could not be elicited. A reduction of intrinsic potassium-dependent inhibition may thus be responsible for LTP.