[Does synaptic elimination contribute to the organization of cerebellar microzones of climbing fiber projection?].

In adult rats whose cerebellar Purkinje cells (PCs) remain polyinnervated by olivary climbing fibres (CFs) after postnatal irradiation, topographical maps of responsive PCs to mechanical stimulation of the third row of contralateral vibrissae show that these cells are more numerous and more diffusely distributed than in the normal rat. PCs responding with the "best responses" are distributed evenly from the midline to 400 microns lateral in the contralateral hemivermis of lobule VII, and not in a parasagittal microzone centred on the plane 200 microns as in the normal rat. Thus it seems likely that synaptic elimination should contribute to microzone formation during postnatal development of the normal cerebellum.