Gonadotropin-releasing hormone (GnRH) neurons, which control reproductive function in vertebrates, originate in the olfactory placode and migrate to the basal forebrain late in embryonic life. Cariboni et al. now report that reelin provides an inhibitory signal that guides GnRH neurons on this tortuous journey (see p. 4709). They show that reelin, an extracellular protein that controls neuronal migration in the cerebral cortex, inhibits the migration of immortalised GnRH-secreting neurons in vitro and that treatment of cultured rat brains with an anti-reelin antibody diverts GnRH neurons away from the basal forebrain. In addition, the brains of developing and adult reeler mice, which lack reelin, have fewer GnRH neurons than do wild-type animals. Interestingly, however, the effect of reelin on GnRH neurons is not mediated through its conventional signalling pathway but through an alternative unknown pathway.

©2005.
2005