Reelin and radial glial cells

Abstract

Defects of the radial glial scaffold in reeler mice were detected and characterized after the radial neuronal migration defects in this mutant had been described (Caviness and Rakic, 1978; Caviness et al., 1988; Pinto-Lord et al., 1982). Based on these findings, it has been hypothesized that radial glial defects contribute to the malpositioning of radially migrating neurons. Experimental evidence that Reelin may directly influence the development of radial glial cells is quite recent (Förster et al., 2002; Weiss et al., 2003; Hartfuss et al., 2003; Luque et al., 2003). The question as to why Reelin should simultaneously act on two different cell types, neurons and radial glial cells, turned out to be a semantic problem when radial glial cells were shown to be precursors of radially migrating neurons (Malatesta et al., 2000; Noctor et al., 2001; Miyata et al., 2001). Thus, when discussing a role of Reelin in the formation of the radial glial scaffold, the changing view of radial glial cell function in cortical development has to be taken into account.