[Slow electrical potentials arising after the initial response in the somatosensory cortex of the brain of the cat upon stimulation of the ventroposterolateral nucleus of the thalamus].

Experiments were carried out on cats under pentobarbital anaesthesia. A single electrical stimulus applied to the VPL nucleus evoked in g. sigmoideus posterior a primary response, followed by delayed negative wave and slow negativity. Generation of these potentials was accompanied by three spike-like deflections in the subcortical white matter. The delayed negative wave was generated in the middle layers of the cortex and was not reflected on its surface. The slow negativity correlated with a transient increase in extracellular potassium concentration. It is suggested that the delayed negative wave reflects the excitation of stellate cells, slow negativity--mainly glial depolarization. The generation of three mentioned responses is connected with the arrival of excitation to the cortex via three systems of afferent fibres projecting from the VPL nucleus to the somatosensory cortex.