Ketamine depression of excitatory and inhibitory cholinergic responses in Aplysia neurons

The effects of ketamine on the cholinergic excitatory and inhibitory (Cl component) responses in Aplysia neurons were examined using the iontophoretic application of ACh and the two-microelectrode voltage clamp technique. Ketamine reduced both responses non-competitively to the same extent in a dose-dependent and reversible manner at concentrations between 10(-6) and 10(-3) M, without changing the reversal potentials. These findings suggest that ketamine depresses the cholinergic responses by affecting the gating mechanism at postsynaptic membranes.