Role of the Thalamus in Sleep Control: Sleep–Wakefulness Studies in Chronic Diencephalic and Athalamic Cats11This paper was written at the Mental Retardation Center of the Neuropsychiatric Institute, University of California at Los Angeles, aided by USPHS Grants HDO5953, HDO4612 and MHO7097. The experiments on the diencephalic and athalamic cats were performed at the Departamento de Medicina Experimental, Escuela de Medicina, Universidad de Chile, Santiago, aided by Grant G68-429 from Foundations Fund for Research in Psychiatry, New Haven, Connecticut, U.S.A.