VISUALIZATION OF OUTGROWING AXONS OF GRAFTED NEURONS BY ANTEROGRADE LABELING WITH PHASEOLUS-VULGARIS-LEUKOAGGLUTININ IN THE MOTOR CORTEX OFTHE RAT

Fetal cerebral cortical tissue was transplanted into an aspirated lesi on cavity made in the sensorimotor cortex of adult rats. Ten weeks aft er grafting, outgrowing fibers from the graft were visualized by an an terograde tracing technique using Phaseolus vulgaris leucoagglutinin ( PHA-L). It was demonstrated that the efferent fibers grew into the nei ghboring host cortical tissue, the corpus callosum and in some cases a pproached caudate/putamen. Characteristic axon arborization with abund ant boutons were found in the host cortical tissue, but only in close vicinity to the grafts. It is concluded that the PHA-L anterograde tra cing technique can be a useful tool to assess the degree of anatomical integration of the transplants into the host tissue.