CGRP expression in the rat olivocerebellar system during postnatal development.

CGRP-like immunoreactivity was studied in the cerebellar cortex and precerebellar nuclei of neonatal rats. From postnatal day (PD) 0 to PD 13-15, CGRP immunoreactivity was transiently found in fiber-like structures around Purkinje cells, defining parasagittal bands. Following the same time course, transient labeling was also found in the inferior olive neurons which, in the adult, distribute their axons to the olivocerebellar compartments corresponding to the immunoreactive bands. It is concluded that CGRP is transiently expressed in specific climbing fiber compartments.