MOLECULAR LAYER OF ADULT CAT CEREBELLAR CORTEX AFTER LESION OF PARALLEL FIBERS - AN OPTIC AND ELECTRON MICROSCOPE STUDY

Section of parallel fibers by a sagittal cut of the adult cat cerebellar cortex results in a diminution in the number of Purkinje cell dendritic spines, seen on Golgi preparations, for a few millimeters to each side of the lesion. Some dendritic trees even appear to lose some terminal branchlets. The loss of dendritic spines has been confirmed in electron microscopy. Three to five days after the lesion, parallel fibers and their synaptic knobs are seen to undergo the opaque type of Wallerian degenaration. A few days later, degenerating terminals are virtually absent in the tissue. This disappearance is accompanied by a diminution in the number of spines in the inter-dendritic fields. After 15 days many dendrites become densely opaque and persist in the tissue for at least as long as 60 days. A relative increase in the number of synaptic boutons is also observed at these time intervals. © 1969.