| Abstract: | The effect of increasing the intracellular calcium ion concentration by various methods (iontophoretic injection into the cytoplasm, generation of a burst of action potentials, addition of uncouplers of oxidative phosphorylation to the external solution, causing release of calcium from mitochondria) on the inward current induced by injection of cAMP into the neuron (the cAMP current) was investigated on the neuron membrane ofHelix pomatia under voltage clamp conditions. In all cases an increase in the intracellular calcium ion concentration was found to lead to an increase in amplitude, and in many cases duration, of the cAMP current. It is suggested that membrane structures responsible for appearance of the cAMP current have two phosphorylation centers: cAMP-dependent and calcium-calmodulin-dependent. The possible role of this process in signal integration at the intraneuronal level is discussed.A. A. Bogomolets Institute of Physiology, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Neirofiziologiya, Vol. 17, No. 1, pp. 78–84, January–February, 1985. |
