The course of direct projections from the abducens nucleus to the contralateral medial rectus subdivision of the oculomotor nucleus in the cat.

We have used autoradiography (tritiated leucine) to investigate the projections of a number of nuclear groups of the cat pons. Some cells of the abducens nucleus have axons that cross the midline, ascend in the opposite median longitudinal fasciculus (MLF) and synapse on the cells of the oculomotor complex which have been identified by others as those innervating the medial rectus muscle.