The term superior paraolivary nucleus refers to one of four cell groups identified by Nissl stain in the periolivary region of the macaque. The others are the medioventral periolivary nucleus, the lateroventral periolivary nucleus, and the dorsal periolivary region ( Paxinos-2009a ). It is also identified by some authors in the rat ( Paxinos-2009b ) and the mouse ( Paxinos-2001 ). Functionally it is part of the subcortical auditory system ( Swanson-2004 ).