[The late prolonged motor discharges during stimulation of the segmentary afferents in rat pups: the age-related characteristics].

In experiments on intact 5-30-day rat puppies under slight urethane narcosis, stimulation of contralateral afferents evoked late prolonged discharges in extensor muscles. Apart from these discharges, studies were also made on the outbursts of autogenic periodic motor activity. The specific feature of late discharges within the first 10 days is their extreme duration and the presence of rhythmic components. With respect to the pattern and temporal parameters, there is a strong similarity between late discharges and autogenic periodic motor activity which is typical of newborn rats. The decrease in the intensity of late discharges in ontogenesis is paralleled by inhibition of autogenic activity. The data obtained indicate that late discharges are genetically related to the ancient property of the central nervous system, i.e. the capacity to self-excitation and maintenance of active state.