COCAINE, AMPHETAMINE AND CATHINONE, BUT NOT NOMIFENSINE AND PARGYLINEINCREASE CALCIUM INWARD CURRENT IN INTERNALLY PERFUSED NEURONS

The influence of cocaine, amphetamine, cathinone, pargyline and nomife nsine on inward calcium current was studied using internally perfused neurons of the snail Lymnaea Stagnalis. While nomifensine and pargylin e inhibited inward calcium current in the concentrations 10(-7)-10(-4) M and did not affect them in the concentrations 10(-9)-10(-8) M, coca ine, amphetamine and cathinone had a biphasic action on inward calcium current, causing activation (10-30 percent) at 10(-9)-10(-7) M, and i nhibition at higher concentrations. Only cathinone caused a shift of t he I-V characteristics of the membrane along the potential axis. It is suggested that drugs of abuse affect membrane excitability and inward calcium current in neurons directly.