[Quasielectrostatic impact on individual neurons: frequency modulation of activity and excitation]

The quasielectrostatic impact (QESI) on the electrical activity of an isolated neuron of mollusc was investigated. It was shown that QESI with the frequencies of (0.05--1) Hz controls the time pattern of the nerve cell electrical activity, producing the frequency modulation (FM) of action potentials (AP) in accordance with the frequency and field intensity applied. The threshold intensity of the transmembrane currents produced by QESI for FM AP effect of the spontaneously active neurorrs are of the order to 10(-13)--10(-12) A, while the threshold shifts of the membrane potentials for different cells vary as (10--100) muV. These figures correlate with the effective field intensity of the order of 0.1--1 V/m in the extracellular space under intact conditions. The obtained data are considered to be important for ephatic cellular interaction and the role of the low level slow potential shifts as the control factor in the formation of pulse activity time pattern of neurons of the intact brain.