[Participation of the substantia innominata in differential inhibition in the cat]

Elaboration of differentiation, its disturbance resulting from bilateral lesion of the substantia innominata and its subsequent restoration was studied in cats. Ablation of the substantia innominata was accompanied by disturbances of the internal inhibition. The initial level, that before the operation, was not obtained even after a long training. It is suggested that substantia innominata modulates cortical activity and its ablation prolongs the afferent synthesis.