Differential effects of granule cell transplantation on two sprouted axonal systems in granuloprival coeruleocerebellar cultures

Exposure of coeruleocerebellar cultures to cytosine arabinoside for the first 5 days in vitro destroyed granule cells and induced sprouting of cortical neurites (Purkinje cell recurrent axon collaterals) and catecholaminergic fibers. Transplantation of such granuloprival cultures with kainic acid-treated cerebellar explants as a source of granule cells resulted in a reduction of silver-positive cortical neurites, but not of histofluorescent catecholaminergic axons. Tissue levels of catecholamines were similar in transplanted and non-transplanted cultures. Differences in types of contacts made with target Purkinje cells in vitro may account for the difference in response to granule cell transplantation by the two axonal groups.