The term pontine central gray refers to a relatively thin layer of cells in the dorsal pontine tegmentum. It forms the floor of the fourth ventricle. Major bounding structures are the medial longitudinal fasciculus of the pons ventrally, the locus ceruleus laterally, and the midline medially. Continuous with the periaqueductal gray rostrally and the central gray of the medulla caudally, it is found in the human ( Paxinos-2012 ), the macaque ( Martin-2000 ), the rat ( Paxinos-2009b ), and the mouse ( Franklin-2008 ). Five small nuclei are embedded in the pontine central gray. Authors differ with regard to the identities of certain of them. All identify four: the dorsal tegmental nucleus, Barrington's nucleus, supragenual nucleus and laterodorsal tegmental nucleus. The fifth for some authors is the lateral tegmental nucleus ( Swanson-2004 ). For others the fifth is the posterodorsal tegmental nucleus ( Paxinos-2012; Paxinos-2009a; Paxinos-2009b; Franklin-2008 ). The pontine central gray and most of the embedded nuclei are included in the functionally defined dorsal pontine gray of Swanson-2004.