RESPONSE OF THE DAMAGED DOPAMINE SYSTEM TO G(M1) AND SEMISYNTHETIC GANGLIOSIDES - EFFECTS OF DOSE AND EXTENT OF LESION

G(M1) ganglioside, administered to young C57/B16J mice with moderate ( approx 85%) 1-methyl-4-phenyl-1,2,3,6-terahydropyridine (MPTP)-induced striatal dopamine depletions, caused a dose-dependent increase in str iatal dopamine levels. This effect was maximal between 7.0 and 30.0 mg /kg and was not apparent at higher and lower doses of G(M1) G(M1) gang lioside treatment had no effect on striatal dopamine levels in mice wi th more extensive lesions of the dopamine system (i.e. approx 93% loss of striatal dopamine). The semisynthetic ganglioside derivative LIGA. 20, administered orally, also increased striatal dopamine levels in m oderately lesioned animals, albeit at lower doses than G(M1) LIGA 20 a dministration also resulted in increased striatal dopamine levels in a nimals with more extensive dopamine lesions, where Gut had no effect. These results show that both G(M1) and its semisynthetic derivative LI GA 20 can partially restore striatal dopamine levels in MPTP-treated m ice and that LIGA 20 is more potent and not subject to the same dose-l imiting effects as G(M1).