Intralaminar nuclei reside within the internal medullary lamina and have numerous reciprocal projections, primarily with the basal ganglia and reticular formation (eFig. 9.30).There are two major functional regions of the intralaminar nuclei: rostral and caudal. The rostral intralaminar nuclei have reciprocal connections with the basal ganglia and also relay input from the ascending reticular activating system. Caudal intralaminar nuclei, which include the large centromedian nucleus, are predominantly involved in basal ganglia circuitry.