“…In GABA-sensitive neurons of Onchidium, ion-selective structures for anion and cation channels were analysed by a chemical modification technique (Omura et al, 1979). Various receptors in Onchidium and Aplysia were further modulated with pharmacological agents (Sato, Maruhashi and Yai 1979 ;Maeno, Sawada and Enomoto, 1979). The structure-activity relationship of oligo-peptides was analysed with snail neurons (Ariyoshi and Takeuchi, 1982).…”