Modulation of the histamine-induced inhibitory response in an identified Onchidium neuron by cyclic nucleotides.

Intrinsic beating activity in the identified molluscan neuron Be-1 can be inhibited for a relatively long time by a short application of histamine. Cyclic AMP enhanced both the amplitude and duration of this inhibitory histamine response (H2-response), while cyclic GMP depressed the H2-response. However, when only these nucleotides were applied, they produced no significant, change in the beating spike activity.