GABAERGIC AND GLYCINERGIC INPUTS TO THE RABBIT OCULOMOTOR NUCLEUS WITH SPECIAL EMPHASIS ON THE MEDIAL RECTUS SUBDIVISION

Contradictory results have been reported about the inhibitory input to the medial rectus subdivision of the oculomotor nucleus of the cat. I n the present ultrastructural study, we quantified the GABAergic and g lycinergic terminals in the various subdivisions of the rabbit oculomo tor nucleus with the use of post-embedding immunocytochemistry combine d with retrograde tracing of horseradish peroxidase. The density of th e GABAergic input to the medial rectus subdivision was as substantial as that to the other subdivisions and the postsynaptic distribution of the GABAergic and glycinergic innervation did not differ among the di fferent oculomotor subdivisions.