[The effect of different regimens of intracellular electrostimulation on the dynamics of neuronal adaptation...

Was studied the influence of rhythmic, random and contingent intracellular electrostimulation on the character of the initial spike activity of individual identified and nonidentified neurons of the isolated CNS of Lymnaea stagnalis snail under the conditions of the controlled experiment. Stimulation and recording of neuron activity were realized via the same microelectrode. In the process of neuron adaptation to the regimens of stimulation used two phases were distinguished being estimated with the help of various statistic criteria. The expression and stability of observed adaptive alterations of endogenous rhythm system were different during the phases determined. At the first phase which reflected a search for the strategy of the optimization of input external influences, the dispersion of interspike intervals and disorder of discharge patterns increased. The true neuron adaptation was developed at the second phase and observed only at contingent reinforcement. Such an adaptation was followed by steady alterations of endogenous rhythm system resulted in minimization or maximization of frequency of associative auto-reinforcements. Alterations accompanying the effect of optimization of external influences were the most expressive at the end of the epoch of corresponding contingent stimulation and remained for some minutes after its cessation. In the paper are discussed the possible mechanisms of the observed endo-neuronal adaptive reconstructions of spike activity.