[Dependence of Retzius' neuron reaction to succinic acid on its initial functional state]

It has been shown on leech Retzius neuron that the effect of succinic acid on impulse activity, respiration and redox state of flavin nucleotides depends on initial values of these parameters with the exception of membrane potential. In this case independent of its initial value the membrane potential becomes equal to 35 +/- 6 mV. The analysis of the evidence obtained has shown that the higher is the activation of cell respiration under the effect of succinic acid, the less are changes in redox-reaction of flavin nucleotides. At stronger activation of respiration the frequency of impulse activity is increased and the value of membrane potential decreased. At smaller changes of respiration the impulse activity frequency is not changed while the membrane potential increases as a rule.