INTRACEREBROVENTRICULARLY TRANSPLANTED EMBRYONIC NEURONAL TISSUE FROMINFLAMMATORY-RESISTANT F344 N RATS DECREASES ACOUSTIC STARTLE RESPONSES IN INFLAMMATORY-SUSCEPTIBLE LEW/N RATS/

Recently, we have shown that intracerebral transplantation of fetal F3 44/N hypothalamic tissue into LEW/N rats converts the LEW/N inflammato ry-susceptible phenotype into an inflammatory-resistant phenotype in L EW/N hosts, Because LEW/N rats also exhibit relatively high acoustic s tartle responses (ASRs) compared to F344/N rats, in the present study we examined the effects on ASR of transplantation of F344/N hypothalam ic tissue into the third ventricle of LEW/N rats, Dissected neuronal t issue from F344/N rats (Day E15-16) was implanted into the third ventr icle of LEW/N rats, After 4 wk of postoperative survival, the animals' responses to acoustic startle stimuli were tested. Compared to naive and sham-operated animals, LEW/N rats transplanted with hypothalamic t issue exhibited significant decreases in ASR amplitudes, A similar dec rease in ASR amplitude was observed in the group of LEW/N rats transpl anted with embryonic striatal tissue, Our results indicate that the th ird ventricular neuronal grafts may modulate behavioral responses in t he LEW/N rats. Although the mechanism of this effect is unknown, these studies suggest that intracerebral neuronal transplantation is a viab le method with which to explore mechanisms of behavioral, neuroendocri ne, and inflammatory response associations.