Responses of an identified Helix pomatia neuron to application of peptides,mediators, prostaglandins,and cyclic nucleotides

Extracellular application of oxytocin, Lys-vasopressin, and Leu-enkephalin to neuron RPa1 ofHelix pomatia evoked the generation of pacemaker potentials and the appearance of potentiation of spike activity of bursting type, characteristic of this cell. Noradrenalin and prostaglandins of the E group had a similar action. Dibutyryl-cyclic AMP, the phosphodiesterase inhibitor papaverine, and sodium fluoride, a nonspecific activator of adenylate cyclase, also initiated or potentiated bursting discharges of the neuron. It is suggested that the effects of oxytocin, Lys-vasopressin, Leu-enkephalin, noradrenalin, and prostaglandins of the E group are mediated through intracellular processes linked with activation of adenylate cyclase by these substances, leading to an increase in the cyclic AMP content in the nerve cell.P. K. Anokhin Research Institute of Normal Physiology, Academy of Medical Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 13, No. 1, pp. 80–87, January–February, 1981.