Amphetamine induced rotation in the assessment of lesions and grafts in the unilateral rat model of Parkinson's disease.

In the unilateral rat model of Parkinson's disease (PD), amphetamine induced rotation is widely used as an index of both lesion deficits and of graft-derived recovery. We have analysed the time course of the rotational response in lesioned rats, and in rats with lesions and dopamine grafts. In lesioned rats, the rotation exhibited a typical dose-dependent response, with low rates of rotation in the first 10 min after injection, rising gradually to a maximum after 20-30 min. Grafted rats exhibited a peak of rotation in the first 10 min after injection, which then fell to a minimum after 30 min. We demonstrate that the response seen in grafted rats is both drug and dose-dependent and show that the rotational profile results from interaction of the grafted and intact striata which exhibit differential temporal responses to the amphetamine.