Some observations on the fiber connections of the di‐ and mesencephalon in the cat. II. Fiber connections of the pretectal region and the posterior commissure

Abstract

THIRTEEN FIGURESAlthough the di-and mesencephalon have been the subject of numerous investigations dealing with the anatomy as well as the physiology of these parts of the brain, many points have remained obscure, and among these may be mentioned the delimitation and functional significance of the area of transition between thalamus and tectum opticum, the pretectal region and posterior commissure of this study. I n particular for the pretectal region, configuration and homologies vary from report to report. The present paper will consider as pretectal region the area of transition between thalamus and tectum opticum, lying immediately lateral to the nucleus of the posterior commissure (Brown, '43), on the inward side of the large-celled nucleus of the optic tract, medial to the nucleus suprageniculatus of the thalamus, fusing caudally with the superior colliculus, and limited ventrally by pretecto-mesencephalic fibers running parallel with or penetrating the medial elements of the trigeminal and medial fillets. I n the cat a distinct nucleus limitans separates the thalamus and pretectal region. Our delimitation corresponds well with the pretectal group as described by Rose ( '42) for the sheep and cat. We agree with this author that sagittal and horizontal sections show up the area much more strikingly than frontal 139

Νευρωνικός Έλεγχος Του Μεγέθους Των Κινήσεων Μετατόπισης Του Βλέμματος: Νευροανατομικές Και Νευροφυσιολογικές Προσεγγίσεις

“…light labeling appeared in the magnocellular subdivision of the nucleus of posterior commissure (NPCm). This result is consistent with early anterograde degeneration studies that reported NPCm to be more directly implicated in eye movements (Bucher and Bürgi 1952;Carpenter and Peter 1970).…”