Effects of oxotremorine after nigrostriatal lesions in rats.

Bilateral injection of 6-hydroxy-dopamine (6-OH-DA) (8mug/4mul) into the substantia nigra causes a significant decrease of the dopamine content in the nucleus caudatus. The intraventricular application of 6-OH-DA (250 mug/10 mul) induces a considerable decrease of dopamine in the caudate nucleus as well as in the globus pallidus and in the medial septal region. Simultaneous changes in norepinephrine content are less spezific. It has to be assumed that there are dopaminergic nerve endings in the glubus pallidus not originating in the substantia nigra. Only after intraventricular applications of 6-OH-DA s short-term and reversible reduction of oxotremorin-induced tremor has been observed. Lesions of the nigrostriatal pathway cause an impairment of motility, probably elicited by rigidity and akinesia. These symptoms correlate better than the tremor to biochemical changes following nigro-striatal pathway lesions.