[Coding the rhythm of adequate stimulation of a crayfish mechanoreceptor neurons by slow oscillations in its firing rate]. / Kodirovanie ritma adekvatnogo razdrazheniia mekhanoretseptornogo neirona raka medlennymi kolebaniiami chastoty ego impul'snoi aktivnosti.

Rhythmic (with periods from 0.5 to 29 sec) adequate stimulations of a single neuron in the crayfish isolated mechanoreceptor induced periodic slow oscillations in its firing rate of which the oscillations with period by 6--10 times exceeding that of stimulation, prevailed. This period was affected by neither stimulation intensity, nor by initial spontaneous firing rate but revealed regular variations on changes of the stimulation frequency. Latencies of the induced oscillations varied from several seconds (for high frequencies) to several minutes (for low frequencies), and on repeated trains of stimuli the latencies grew shorter. After cessation of stimulation these oscillations persisted for several minutes; they could be transformed by another stimulation frequency in 1--3 min. The data suggest that the coding of stimulation rhythm in the firing rate oscillations is related to rhythms of energy metabolism in the nervous cell.

[Relationship between the spike responses of crayfish mechanoreceptor neurons and the initial functional state and degree of aggregation of their Nissl substance]. / Zavisimost' impul'snykh reaktsii mekhanoretseptornogo neirona rechnogo raka ot iskhodnogo funktsional'nogo sostoianiia i stepeni agregatsii veshchestva Nisslia.

The discharges of a single neuron in the crayfish isolated stretch receptor to square standard adequate stimuli were studied. The following parameters were analyzed: response duration, number of impulses per burst, inhibitory pause duration, amplitude and shape of the frequencygram. Preliminary desaggregation of Nissl substance correlated with increase in discharges. When initial frequency of the discharge was low or when the stretch receptor was in resting state, especially in winter time, and the Nissl substance showed high degree of aggregation, discharges to the same stimuli were weaker, and their range diminished. It is suggested that intensified discharges are determined by intracellular redistribution and uptake of calcium which take place during desaggregation of the Nissl substance.