ACTIONS OF CERTAIN AMINES ON CEREBRAL CORTICAL NEURONES

Abstract

A number of derivatives of tryptamine and phenethylamine, and certain other compounds, were tested on neurones in the cerebral cortex of cats by iontophoretic release from micro‐pipettes. The characteristic action of many of these compounds was a depression of the neuronal discharge initiated by synaptic activity or by the application of l‐glutamate; imidazolylacetic acid, dopamine, ephedrine and ergometrine were particularly effective. Catechol amines, hydroxytryptamines and imidazolylacetic acid had a relatively quick and rapidly reversible action, not unlike that of γ‐aminobutyric acid, whereas ephedrine and derivatives of lysergic acid diethylamide caused a slower and more prolonged depression of the amplitude of spikes, rather like atropine. Several compounds, including 5‐hydroxytryptamine, adrenaline and ergometrine, could also excite the same neurone when larger amounts were applied. A few substances, such as dopa and methylergometrine, had a predominantly excitant action. 1963 British Pharmacological Society