Cholinergic disinhibition in hippocampal slices of the rat.

In hippocampal slices of the rat maintained in vitro the addition of carbachol to the perfusion medium caused a depolarization accompanied by a conductance decrease and a block of inhibitory postsynaptic potentials in CAl pyramidal cells. During tetrodotoxin poisoning a smaller depolarization with conductance decrease was observed. Atropine blocked the effects of carbachol.