[Classification of the responses of a giant neuron from the snail Acatina fulica Férussac, caused by inhibitory sugstances depending on chlorine ions].

GABA, three of its derivatives (l-GABOB, d-GABOB and delta-amino valeric acid), acetycholine (Ach), dopamine (DA) and l-Phe-Tyr all inhibit an identifiable giant neurone (the TAN, tonically autoactive neurone) of Achatina fulica. These effects were examined by microdrop application in two different conditions: in physiological solution and in the absence of chloride ions. The results show that the relatively transient (rapid) inhibitions caused by GABA, by its derivatives and by Ach are dependent on chloride ions; the relatively maintained (long-lasting) inhibitions, caused by DA and l-Phe-Tyr, are independent of chloride ions.