title: N-cadherin and Ng-CAM/8D9 are involved serially in the migration of newly generated neurons into the adult songbird brain.
abstract: In the adult avian forebrain, neurons continue to be produced in the subependymal zone (SZ), from which they migrate upon radial fibers. To identify ligands regulating this process, we studied N-cadherin and Ng-CAM/8D9 expression in HVC, a neurogenic region of the canary neostriatum. N-cadherin was relatively restricted to the SZ and was expressed by dividing, [3H]thymidine-labeled precursor cells. However, cellular N-cadherin was down-regulated prior to neuronal migration from the SZ. Addition of anti-N-cadherin Fab hastened neuronal migration from adult SZ explants, without influencing neuronal number. Unlike N-cadherin, Ng-CAM/8D9 was expressed by migrating neurons. Anti-8D9 Fab inhibited neuronal migration upon cultured ependymoglia, which did not express Ng-CAM/8D9. Thus, the departure of new neurons from the adult SZ may require their suppression of N-cadherin, whereas their subsequent migration and survival may depend upon neuronal expression of Ng-CAM/8D9 and its interaction with a heterophilic radial cell receptor.
authors.affiliation: Department of Neurology and Neuroscience, Cornell University Medical College, New York, New York 10021.
authors.forename: K
authors.initials: K
authors.lastname: Barami
authors.forename: B
authors.initials: B
authors.lastname: Kirschenbaum
authors.forename: V
authors.initials: V
authors.lastname: Lemmon
authors.forename: S A
authors.initials: SA
authors.lastname: Goldman
mesh_terms: D000818:Animals; D001717:Birds / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000378:metabolism*; D015820:Cadherins / Q000502:physiology*; D002171:Canaries; D015816:Cell Adhesion Molecules, Neuronal / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D004805:Ependyma / Q000166:cytology; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D008938:Mitosis; D009412:Nerve Fibers / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000502:physiology; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D019063:Tenascin; D014018:Tissue Distribution
chemical_list: D015820:Cadherins; D015816:Cell Adhesion Molecules, Neuronal; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D019063:Tenascin