Investigation of Changes in Membrane Potential and Rhythmic Activity of the Retzius Neuron upon Stimulation of the Sensory P-Neuron

It was found that in "natural neural networks", ganglia of the nervous system of a leech, the frequency of rhythmic excitation (a series of nerve impulses, RE) of one neuron is modulated upon activation of other neurons. Changes in the electrophysiological characteristics of the leech Retzius cell in response to electrical stimulation of one of the sensory neurons (P-cells) were revealed. Registration of changes in the membrane potential of neurons, as well as electrical stimulation of the P-cell was carried out using microelectrodes introduced into the cells. It was found that during electrical stimulation, P-cells increase the frequency of spontaneous RE of Retzius cells, the membrane potential of P-cells increases, but Retzius cells do not change. With an increase in the duration of stimulation, the RE frequency increases in both the P-cell and the Retzius cell. It has been found that RE Retzius cells, upon stimulation of P-cells, arise against the background of RE of the Retzius cell. Thus, during RE of sensory neurons and synaptic transmission to the Retzius cell, RE frequency modulation occurs. According to the authors, changes in the frequency of spontaneous RE of the Retzius neuron in the "natural neural network" are associated not only with a change in the RE frequency during excitation along nerve fibers from skin receptors, but also with the transformation of RE both between cells of one ganglion and between cells in different ganglia leech nerve chain

This work was financially supported by the RSF (grant RSF no. 19-79-30062)

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