A pretectofacial projection in the cat: a possible link in the visually-triggered blink reflex pathways

A direct projection from the pretectum to the facial motor nucleus was shown to exist in the cat by the anterograde and retrograde horseradish peroxidase (HRP) methods. Pretectofacial fibers arise from the olivary pretectal nucleus and end mainly in the dorsal division of the facial motor nucleus, bilaterally, with a contralateral predominance. It is known that the olivary pretectal nucleus receives retinal fibers, and that the dorsal division of the facial motor nucleus contains orbicularis oculi motoneurons. Thus, the pretectofacial fibers are assumed to cause protective lid closure with certain visual stimuli.