Mutual modulating effects of serotonin and dopamine on neurons of rat spinal ganglia

It was established in experiments on isolated rat spinal ganglia that the introduction of dopoamine (0.01–1.0 µM) into a superfusate potentiates the depolarizing responses of the neurons evoked by the action of serotonin, which is delivered from a micropipette under pressure, while the addition of serotonin in the same concentrations potentiates the depolarizing responses of the neurons evoked by the action of dopamine. The mutual potentiation of the effects of dopamine and serotonin depends on the concentration of the monoamines and is eliminated by blockers of the D₁- (but not D₂-dopamine) and type 2 serotonin (but not IA) receptors. The mutual potentiation of the effects of monoamines is of a postsynaptic nature and is associated with a change in the intracellular concentration of second messengers (Ca²⁺ and cAMP).A. M. Gor'kii Donetsk Medical Institute, Ministry of Health of the Ukrainian SSR. Translated from Neirofiziologiya, Vol. 23, No. 2, pp. 168–173, March–April, 1991.