[Changes in the concentration of extracellular potassium and the slow negative potential in the somatosensory area of the cortex in response to stimulation of the ventroposterolateral nucleus of the thalamus in the cat].

A single electrical stimulus applied to the VPL nucleus with intensity, strong enough to elicit in gyrus sigmoideus posterior slow negativity following the primary response, caused a local increase in [K+]0 reaching 0.2 mM. On the basis of this finding it is supposed that the slow negativity reflects mainly depolarization.