The term caudal pontine reticular nucleus refers to a major cellular component of the reticular formation (classical) in the pontine reticular formation ( Carpenter-1983 ). Identified by Nissl stain, it is variously described as continuous across the midline or bounded medially by the raphe nuclei (classical) and the reticulotegmental nucleus. It is bounded dorsomedially by the medial longitudinal fasciculus of the pons, ventromedially by the trapezoid body and ventrolaterally by the superior olivary complex . The remainder of its boundaries are defined by several smaller reticular and cranial nerve nuclei. It is bounded rostrally by the rostral pontine reticular nucleus and caudally by the central medullary reticular group. It is found in the human ( Carpenter-1983 ), the macaque ( Martin-2000 ), the rat ( Swanson-2004 ) and the mouse ( Hof-2000 ). Some authors distinguish the most ventromedial portion as the ventral part of the pontine reticular nucleus ( Hof-2000; Paxinos-2009b ). In the rat the majority of noradrenergic neurons of the A5 cell group are located in this nucleus. Functionally it belongs to the reticular formation (functional) of the subcortical motor system ( Swanson-2004 ).