Striatal reconstruction by striatal grafts

It is now well established that striatal lesions induce motor and cognitive deficits in rats, and that grafts of embryonic striatal tissue can survive , integrate into the lesioned host brain and alleviate the behavioural defi cits in both motor and cognitive spheres. How? Since normal striatal functi on is dependent upon it's integration within a connected cortical-subcortic al neuronal circuitry, and the deficits following striatal damage appear to reflect a "disconnexion" syndrome, the observation of recovery suggests th at the grafts re-establish a connected circuitry within the host brain. Evi dence to corroborate or refute this hypothesis, in comparison with a less-s pecific mechanism (or mechanisms) of recovery, is considered, including ana tomical, electrophysiological and neurochemical demonstrations of functiona l circuit reconstruction in the host brain by striatal tissue transplants.