Cadherins guide migrating Purkinje cells to specific parasagittal domains during cerebellar development.

Several cadherins are expressed in parasagittal Purkinje cell domains, which can be defined by their afferent and efferent connectivity in the developing and mature cerebellum. By in vivo electroporation in chicken embryos, we demonstrate that Purkinje cell progenitors, which overexpress cadherin-6B or cadherin-7, distribute preferentially to those Purkinje cell domains, which express the respective cadherin endogenously. This differential distribution may be based, at least in part, on the guidance of migrating neurons along neurites that express the same cadherin. Selective induction of apoptosis and cadherin-based cell sorting within cortical domains do not seem to contribute to the differential distribution. These results show that cadherins can tell early neurons where to integrate in functional brain gray matter, possibly by a cadherin-based homotypic adhesive mechanism.