[Postsynaptic reactions of neurons of the sensomotor cortex of the cat during evoked and self-sustained rhythmic activity of the "peak-wave" type].
Intracellular correlates of evoked rhythmic cortical "spike-and-wave" potentials produced in sensorimotor cortex during 3/s stimulation of the thalamic relay nucleus (VPL) and of self-sustained "spike-and-wave" afterdischarges following 8-14/s stimulation of the same nucleus were studied in acute experiments on cats immobilized by myorelaxants. Intracellular recordings of pyramidal tract neurons revealed that different components of evoked "spike-and-wave" potentials, i. e. the spike-like negative wave and the long lasting negative wave, are postsynaptic in origin: the first is due to EPSPs with spike discharges, and the latter--to IPSPs of cortical neurons. Components of "spike-and-wave" afterdischarge mostly reflect the paroxysmal depolarizing shifts of the membrane potential of cortical neurons. After cessation of sustained "spike-and-wave" activity the long-lasting hyperpolarization accompanied by inhibition of spike discharges and subsequent recovery was observed in cortical neurons. It is presumed that the negative wave of the evoked "spike-and-wave" potential as well as slow negative potentials of direct cortical and primary responses reflect IPSPs of deeper parts of pyramidal tract neurons, while the waves of the sustained "spike-and-wave" afterdischarges are due to paroxysmal depolarizing shifts in cortical neurons.
D000818:Animals; D002415:Cats; D004553:Electric Conductivity; D004558:Electric Stimulation; D004569:Electroencephalography; D005071:Evoked Potentials; D009044:Motor Cortex / Q000502:physiology*; D009433:Neural Inhibition; D011712:Pyramidal Tracts / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology*; D009435:Synaptic Transmission; D013787:Thalamic Nuclei / Q000502:physiology*
Postsinapticheskie reaktsii neĭronov sensomotornoĭ kory koshki vo vremia vyzvannoĭ i samopodderzhivaiushcheisia ritmicheskoĭ aktivnosti tipa "pik-volna".