Abnormal development of the facial nerve nucleus in reeler mutant mice.

The architectonics and development of the facial nerve nucleus have been compared in reeler and normal mice. In both genotypes neurons were generated at E10, and their axons entered the facial nerve at E11. Cell bodies migrated radially at E12-E13, possibly along radial neuroepithelial fibres. From the end of migration, the reeler nucleus was less superficially located and less clearly organised than the normal nucleus. The normal adult architectonic divisions were present in the mutant, but less distinct than in the normal nucleus. These observations have been related to other data on the developmental biology of the reeler brain. It is suggested that the reeler gene could affect an interaction between neurons or between neurons and radial fibres at the end of migration.