Table 1.

Striatal DA and DOPAC levels in acute and chronic young adult (6–10 weeks old) MPD.

Animal group	N	DA (ng/mg tissue)	DOPAC (ng/mg tissue)
Young acute control	5	13.81 ± 1.73	1.43 ± 0.39
Young acute MPDa	5	6.34 ± 0.86*	0.74 ± 0.27*
Young chronic control	7	12.97 ± 1.33	1.65 ± 0.47
Young chronic MPDb	7	3.26 ± 0.41**	0.48 ± 0.36**

^aThe young acute MPD received two injections of MPTP hydrochloride (25 mg/kg/dose made in saline, s.c.) 2 h apart. Experiments were conducted 2 h post-acute treatment. The acute control group received saline only.

^bThe young chronic MPD received 10 doses of MPTP hydrochloride (25 mg/kg/dose in saline, s.c.) in combination with an adjuvant, probenecid (250 mg/kg/injection dissolved in dimethyl sulfoxide, i.p.). The 10-dose regimen was administered on a 5-week schedule with an interval of 3.5 days between injections. Experiments were conducted 6 weeks post-chronic treatment. The chronic control group received probenecid only.

*Significantly lower than the acute saline control group (P < 0.002).

**Significantly lower than the chronic probenecid control group (P < 0.0001).