Normal neuronal migration
Ontogenesis of both central and peripheral nervous systems depends on basic, molecular and cellular mechanisms of the normal neuronal migration. Any deviation leads to neural malformations. All neural cells and structures derive from the neural ectoderm, which under the influence of the notochord an...
| Autores: | , |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2011 |
| País: | México |
| Institución: | Universidad Nacional Autónoma de México |
| Repositorio: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:58220040008 |
| Acceso en línea: | https://www.redalyc.org/articulo.oa?id=58220040008 |
| Access Level: | acceso abierto |
| Palabra clave: | Medicina cerebral cortex Neuronal migration molecular mechanisms |
| Sumario: | Ontogenesis of both central and peripheral nervous systems depends on basic, molecular and cellular mechanisms of the normal neuronal migration. Any deviation leads to neural malformations. All neural cells and structures derive from the neural ectoderm, which under the influence of the notochord and the molecules Noggin and Chordin, is transformed consecutively into neural plate, neural groove, neural tube and primary vesicles. Of the latter, the most rostral, the prosencephalon, two vesicles are bilaterally generated, the telencephalon and in the middle, the unpaired diencephalons. The telencepahlic vesicles generate the cerebral hemispheres and the lateral ventricles; the latter constitutes the main source of progenitor neuroepithelial cells (NEC) in the subventricular zone. The NEC massively migrates to constitute the cerebral cortex and other hemispheric structures in the telencephalon and diencephalon. The NEC expresses a broad repertory of markers: BLBP, GLAST, vimentin, tenascin, S100β and, in primates GFAP; in a sequential order the NEC form the first cortical layer formed by the marginal zone and the subplate. The marginal zone harbors the Cajal-Retzius reelin positive neurons and reelin negative neurons. Reelin, besides signaling stop to migrating neurons, also participates in ordering the cortical layers; it is known that in mutant mice lacking reelin cortical layers are disrupted. Genetic studies indicate that ApoER2, Vldr (both reelin receptors) and Dab1, reelin signaling adaptor protein, enter into a common pathway leading Dab1 to phosphorylation in migrating neurons. Cortical pyramidal neurons generate at germinal zone; interneurons generate both in Vz and SVZ in medial ganglionic eminence and caudal GE. Two types of neuronal migration coexist, radial and tangential. In radial migration, the neurons move perpendicular to marginal zone and radial glia serves as a scaffold to migrating cells; in the tangential way, neurons migrate in parallel to brain surface guided by semaphorins, neuropilins, cell adhesion molecules, neuregulins, chemokines and the slit and robo families of attractant and repellent molecules. The migratory cycle of neurons involves leading process dynamics and somal translocation, which involves the movement of perinuclear material, organelles and nucleus. Leading process stability depends on the microtubular array that links the leading edge of the cell with the soma... |
|---|