Amphetamine-induced rotation reveals post 6-OHDA lesion neurochemical reorganization

Early postlesion amphetamine-induced contralateral rotation has been linked to intraneuronal dopamine (DA) accumulation and transmitter release associated with axonal degeneration. Animals in the present study sustained severe unilateral depletion of striatal DA with or without a near-complete loss of ipsilateral mesolimbic DA. Contralateral rotation to 1.0 mg/kg (+)-amphetamine was observed on days 1 and 4 postlesion, and was greatly enhanced in mesolimbic-lesioned animals on day 4. On days 7 and 14, very little contralateral turning was observed and there was an emergence of low-rate ipsilateral rotation. These changes in direction and magnitude of rotational response suggest neurochemical adaptations which continue beyond initial periods of intraneuronal accumulation and degeneration-induced release.