Qualitative identity of cerebral neuronal membrane actions of 5HT LSD, and CPZ.

Extra- and intracellular recording of the cerebral cortical actions of close-arterially injected serotonin (5HT) and LSD in the cat shows them to be powerful synaptic inhibitors. They are specifically and differentially blocked by chlorpromazine (CPZ). The membrane parameters including spike generation, polarization, transmembrane conductance, and IPSPs show that all three produce qualitatively identical changes, which must, therefore, be presumed to act on the same receptors with block by CPZ taking place because of competitive inhibition.

Hallucinogen-tranquilizer interaction: its nature.

Study of the competition between hallucinogens and tranquilizers at cerebral synapses and on behavior in various species of animals indicates a continuum of effects from protection to dominance of tranquilizer toxicity as the dose of tranquilizer increases. Data on cat and monkey behavior, supplementing that on the rat, show that it is possible to arrive at a tranquilizer dose that can aggravate instead of protect, in accord with the competitive inhibitory nature of the interaction of hallucinogen and tranquilizer.