Multiple Postsynaptic Actions of the Giant Dopamine-Containing Neurone R.Pe.D.1 of <i>Lymnaea Stagnalis</i>

Abstract

ABSTRACT Evidence is presented that the giant neurone R.Pe.D.1 is mono-synaptically connected to follower cells in the right parietal and visceral ganglia and has excitatory, inhibitory and biphasic postsynaptic actions. The spike to e.p.s.p. latency is increased to a new fixed value by high calcium saline, but not by saline in which both the Ca2+ and Mg2+ concentrations have been increased in proportion to one another. Three distinct classes of p.s.p. latency exist. Short e.p.s.p. and b.p.s.p. latencies of ca. 16·0 to 20 ms have been observed, as have longer e.p.s.p. and b.p.s.p. latencies, ca. 38−44 ms. An i.p.s.p. with a latency to onset of ca. 182 ms occurs on the J cells.