[Changes in neuronal excitability elicited by subthreshold depolarization as a possible mechanism of interval-selective interrelations in the central nervous system].

The cellular process that may be considered as a mechanism of interval-selective functional interrelations between neurons in the mammalian brain identified in the previous studies has been studied in neurons of mollusc Lymnaea stagnalis. This process consists of regular excitability changes resulting in high probability (0.6-1) of the impulse reaction elicited by the subthreshold depolarization current shock applied in time intervals (specific, individual for each neuron) after identical subthreshold conditioned stimulus. It is shown that a cycle of the excitability changes after subthreshold depolarization is not a result of the time summation of electrotonic, local or postsynaptic potentials of a neuron, but may be represented by the endogenous (cytoplasmatic) process insensitive to the mediator application and reversibly changed when one of the modulator peptide (bombesin) is applied.