Acetylcholine Receptors in Aplysia Neurones

Abstract

In 1962, Tauc and Gerschenfeld reported that an ionophoretic injection of acetylcholine (ACh) causes a depolarizing response in some Aplysia neurones and a hyperpolarizing response in others. Both of these responses could be blocked by (+)-tubocurarine. The additional finding that the depolarizing responses could be selectively eliminated by hexamethonium showed that the two effects were mediated by different receptor types. Moreover, certain spontaneous i.p.s.ps in the ACh-hyperpolarized cells were, like the ACh response, blocked by (+)-tubocurarine, suggesting that at least one of the two receptor types plays a physiological role.