Apomorphine induces latent rotation in lesioned rats, amphetamine does not.

Rats with unilateral 6-hydroxydopamine (6HDA) lesions of one nigrostriatal pathway were used to compare the efficacy of apomorphine (Apo) and (+)-amphetamine (Amph) at inducing latent rotational behavior. Rats treated with Apo rotated contralaterally acutely after drug treatment and subsequently, weeks after drug treatment, exhibited rapid contralateral circling when re-introduced to the rotation environment. Amph treated animals, on the other hand, rotated ipsilaterally acutely after drug treatment and exhibited no latent drug effect.