Functional recovery following transplantation of ventral mesencephalic cells in rat subjected to 6-OHDA lesions of the mesolimbic dopaminergic neurons.

Lesion of mesolimbic dopaminergic neurons induces hypoactivity and hypo-exploration in a new environment, lack of hyperactivity to amphetamine and hyperresponsiveness to apomorphine. Transplantation of embryonic dopaminergic cells from rat embryos into the deafferented nucleus accumbens restores, 8 weeks after grafting, some of the deficits obtained after the lesion. Spontaneous activity and behavioral responses in an open-field are improved and some of the grafted rats show a complete recovery of amphetamine-induced hyperactivity. However, hyperresponsiveness to apomorphine has not been significantly reduced by the treatment. These results indicate that transplanted dopaminergic neurons can restore some of the functional activities of the n. accumbens.