INDUCTION OF A SLOW CAMP-SENSITIVE SODIUM CURRENT IN MOLLUSK NEURONS BY ACTIVATORS OF G-PROTEINS

The experiments have been carried out with isolated Helix pomatia neur ons by the method of two-microelectrode voltage clamping. cAMP and the activators of G-proteins, F-, GTP and Gpp (NH)p, were injected via io nophoresis into the neurons using a seven-channel microelectrode. It i s found that the G-protein activators induce both input and output cur rents in the neurons where slow sodium current can be activated by cAM P. The input G-activated and cAMP-activated currents are similar in ki netics, voltage dependence and reverse voltage. The G- and cAMP-respon ses are not additive. The results obtained allow the conclusion that t he G-protein activators can stimulate the slow cAMP-sensitive sodium c hannels.