TANGENTIAL MIGRATION OF LUTEINIZING-HORMONE-RELEASING HORMONE (LHRH) NEURONS IN THE MEDIAL TELENCEPHALON IN ASSOCIATION WITH TRANSIENT AXONS EXTENDING FROM THE OLFACTORY NERVE

During embryonic development, luteinizing hormone-releasing hormone (L HRH) neurons migrate to the brain from the medial olfactory epithelium through the olfactory nerve. LHRH neurons enter the brain and migrate tangentially along the medial edge of the telencephalon in close asso ciation with a neural cell adhesion molecule (N-CAM) enriched fiber bu ndle. In the current work we wished to determine whether this N-CAM en riched fiber bundle is an extension of the olfactory nerve. Ablation e xperiments, immunocytochemistry and diI implants all suggest that LHRH neurons migrate in association with a very small subset of transient N-CAM enriched neuronal processes which extend out of the olfactory ne rve proper to the septal-preoptic area.