The term oral paramedian nucleus refers to the more caudal of two cell groups located in the floor of the fourth ventricle between the nucleus prepositus and the midline of the medulla in the human ( Paxinos-2012 ) and the macaque ( Paxinos-2009a ). The other is the dorsal paramedian nucleus. Some authors regard the oral nucleus as part of the dorsal nucleus ( Crosby-1962 ).