Climbing fiber destruction affects dendrite and spine membrane organization in Purkinje cells.

Destruction of climbing fibers, one of the presynaptic inputs to Purkinje cells, was achieved by intraperitoneal injection of 3-acetylpyridine in rats. Freeze-fracture morphology of the Purkinje cell membrane was studied under these conditions. Quantitative analysis reveals a decrease in the number of intramembrane particles (IMP) in the membrane E-face of dendrites and spines of large dendrites, both postsynaptic targets for climbing fibers. The membrane of the perikaryon and of the spines from the spiny branchlets were unaffected by climbing fiber destruction. These results suggest that under the conditions studied, the membrane organization in well-defined areas of the Purkinje cell may be influenced by presynaptic factors.