Postsynaptic pharmacology of psychoactive substances in Aplysia californica

The effects of antidepressants and neuroleptics on postsynaptic iontophoretic responses to acetylcholine and dopamine have been examined in identified neurons of the central nervous system of Aplysia californica. The results demonstrate an antidopaminergic action of neuroleptics in accordance with in vivo and in vitro results in higher animals. Some of the antidepressant drugs tested also caused a blockade of dopamine hyperpolarizing responses. The incidence of anticholinergic activity of both antidepressants and neuroleptics also correlates well with other systems. The results furthermore suggest that the psychoactive drugs tested behave as antagonists for the neurotransmitter postsynaptic receptor sites.