Table 2.

Neurochemical measures 5 days following bilateral infusion of soluble GFRα1 or vehicle to the SN of aged rats

Dependent measure	Brain region	Bilateral vehicle infusion to SN	Bilateral soluble GFRα-1 infusion to SN	p value of unpaired two-tailed t-test
ng DA per mg protein	Striatum	318.2±12.09	341.0±8.51	0.17
	SN	9.5±0.55	8.2±0.92	0.27
	NAc	150.5±14.56	151.2±10.98	0.97
	VTA	33.1±2.85	30.0±3.88	0.55
ng TH per µg protein	Striatum	0.53±0.080	0.64±0.091	0.41
	SN	0.051±0.0055	0.046±0.0093	0.71
	NAc	0.16±0.037	0.15±0.035	0.91
	VTA	0.28±0.032	0.28±0.045	0.99
ng DA per ng TH	Striatum	0.65±0.105	0.58±0.079	0.60
	SN	0.20±0.013	0.20±0.025	1.00
	NAc	1.04±0.115	1.11±0.172	0.76
	VTA	0.13±0.013	0.12±0.017	0.58
pmol DOPAC per pmol DA	Striatum	0.075±0.0029	0.076±0.0058	0.94
	SN	0.10±0.009	0.12±0.004	0.17
	NAc	0.13±0.006	0.13±0.009	0.76
	VTA	0.15±0.007	0.16±0.009	0.50

DA per protein, TH per protein, DA per TH, and DOPAC per DA (a measure of DA turnover) were measured in the striatum, SN, NAc, and VTA of aged rats 5 days after direct bilateral infusion of 1 ng soluble GFRα1 (n=4) or vehicle (n=4) into the SN. The data reflect the mean ± SEM for each group and brain region. The measures were compared for each brain region between the vehicle and GFRα1-treated groups using an unpaired twotailed t-test. None of these measures was significantly different between the treatment groups for any of the brain regions