HYPOTHALAMIC BUT NOT CORTICAL GRAFTS INDUCE RECOVERY OF SEXUAL-BEHAVIOR AND CONNECTIVITY IN MEDIAL PREOPTIC AREA-LESIONED RATS

We have previously shown that hypothalamic fetal brain grafts induced recovery of sexual behavior in medial preoptic area (MPOA)-lesioned ma le rats. In the present series of experiments, male rats with complete ly abolished sexual behavior by MPOA lesions received either hypothala mic or frontal cortical fetal grafts. The animals that received hypoth alamic grafts showed a gradual recovery of sexual behavior. In contras t, those animals who received cortical grafts did not recover sexual b ehavior during the 15 weeks after the graft. In addition, to evaluate the connectivity of the grafted tissue with the host brain, a retrogra de tracer, fluorogold, was injected in the dorsal tegmental area. Fluo rogold-labeled cells were found in the hypothalamic, but not in the co rtical grafts. These results suggest that specificity of the grafted t issue and connectivity between brain grafts and host tissue are necess ary for the recovery of male sexual behavior in MPOA-lesioned rats.