[Self-sustaining rhythmic activity of the "peak-wave" type and responses of neuronal and glial cells of the sensomotor cortex of the cat].

In acute unanesthetized immobilized cats a sequence of fast hyperpolarization and long-lasting depolarization was found in pyramidal tract neurons of the sensorimotor cortex during tetanic stimulation (8-14/s for 10 s) of the ventro-postero-lateral nucleus of the thalamus. During long-lasting depolarization after cessation of stimulation self-sustained rhythmic paroxysmal depolarizing membrane potential shifts appeared which were terminated by long-lasting hyperpolarization. In glial cells only depolarization was observed during stimulation as well as during self-sustained "spike-and-wave" rhythmic activity. Hyperpolarization in glial cells appeared only after its termination in neurons. It is suggested that the long-lasting changes in the membrane potential of cortical elements may play a particular role in formation and cessation of "spike-and-wave" rhythmical activity.