Abstract
AbstractRetinal projections to the thalamus and midbrain were studied by the Nauta‐Laidlaw technique. After unilateral enucleation, degeneration was found in five areas: dorsal lateral geniculate nucleus (LGNd, thalamus), ventral lateral geniculate nucleus (LGNv, subthalamus), nucleus of optic tract (NOT, pretectum), superior colliculus (S.C., tectum), and accessory optic nuclei (AON, tegmentum). Degeneration after focal lesions in nasal retina made by photocoagulation is found in four areas of the contralateral LGNd: Laminae A and B, nucleus interlaminaris centralis (NIC), and the medial part of nucleus interlaminaris medialis (NIM). Temporal lesions lead to degeneration ipsilaterally in three areas: lamina A1, NIC, and the lateral part of NIM. Central lesions are followed by bilateral projections; the area of degeneration on each side is greater than that of peripheral lesions of comparable size. Focal degeneration is found in NIM after either central or peripheral retinal lesions. Each retina projects to both NOT and both S.C. In NOT, degeneration following nasal lesions is strictly contralateral while after temporal lesions is mainly ipsilateral. A bilateral projection of temporal retina to NOT constitutes an exception to theories of chiasmal decussation. Both nasal and temporal projections to AON are wholly crossed, thus constituting another example of projection of temporal retina to the contralateral side, Nasal fibers project contralaterally and nearly all temporal fibers ipsilaterally to S.C.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call