Do neurons in the vertebrate CNS migrate on laminin?

AUTOR(ES)

Liesi, P

RESUMO

In adult rat brain the extracellular matrix glycoprotein, laminin, is found only in basement membranes, but is transiently expressed by astrocytes after brain injury. Here, I show that laminin also appears in immature brain cells during CNS development, and that its presence coincides with phases of neuronal migration. In early embryos, laminin is seen throughout the whole thickness of the forming brain, and is apparently synthesized by the cells, as judged by its intracytoplasmic localization. As development proceeds, intracellular laminin becomes restricted to the periventricular regions while punctate deposits of laminin follow the course of vimentin-positive radial glial fibers. In most brain regions, the adult pattern of laminin expression is achieved by birth. In the post-natal rat cerebellum, however, laminin is detected in external granule cells, in Purkinje cells, and in punctate deposits along the radial Bergmann glial fibers. By day 24 after birth, when the migration of external granule cells is complete, all laminin immunoreactivity disappears from these structures. The transient expression of laminin in regions where neurons are migrating raises the possibility that laminin plays a role in neuronal migration during CNS development.

Documentos Relacionados

• The histamine H4 receptor is functionally expressed on neurons in the mammalian CNS
• Central nervous system neurons migrate on astroglial fibers from heterotypic brain regions in vitro.
• Laminin-immunoreactive glia distinguish regenerative adult CNS systems from non-regenerative ones.
• Serotonin induces or inhibits neuritic regeneration of leech CNS neurons depending on neuronal identity
• Rapid desensitization of glutamate receptors in vertebrate central neurons.