Current(I)-voltage(V) relationships of the neuromembrane of an identifiable giant neurone of an Afican giant snail (Achatina fulica Férussac) in the presence of an inhibitory tripeptide,L-Lys-L-Phe-L-Tyr

Summary An inhibitory tripeptide, L-Lys-L-Phe-L-Tyr, caused membrane hyperpolarization of the TAN (tonically autoactive neurone) resulting in an elevated firing level. The tripeptide, however, did not markedly affect either the TAN I–V curve or the firing pattern obtained by transmembrane triangular current injection.The authors wish to express their thanks to Prof. M. Kohsaka and Prof. A. Mori of Okayama University for the helpful advice, and to Dr A. Inoue of Daiichi Pharmaceutical Co. for the donation of L-Lys-L-Phe-L-Tyr.