a and c. Monoamine levels in midbrain. a. Monoamine levels were significantly increased in midbrain of mice fed with rapamycin for 16 weeks (F(1,55)=11.57; P=0.0013, two-way ANOVA) and c. for 40 weeks (F(1,56)=65.8; P<0.0001, two-way ANOVA). DA was significantly increased in midbrain at 16 weeks of rapamycin treatment (P=0.04) while DA, DOPAC, HVA, 5-HT AND 5-HIAA were significantly increased in midbrain at 40 weeks (P=0.007, P=0.01, P<0.001, P=0.02 and P=0.01 respectively). NE levels showed a significant increase when analyzed independently (P=0.018, unpaired Student’s t test). n=5 for each group. c and d. Monoamine levels in hippocampus. Monoamine levels were not significantly different between experimental groups at 16 weeks (b) nor at 40 weeks (d) of rapamycin treatment. e and f. No differences in DA metabolism were found among experimental groups at 16 (e) nor at 40 (f) weeks of rapamycin treatment. g-h. Cortical NET levels are not affected by rapamycin treatment. e. Representative immunoblots of cortical lysates from control- and rapamycin-treated mice probed with antibodies specific for the indicated proteins. f. Quantitative densitometric analyses indicate that cortical NET levels are not affected by rapamycin treatment (P>0.05, unpaired Student’s t test). n=5 for each group. Data are means ± SEM.