a, c, e, g. Representative immunoblots of whole brain (a and e) or hippocampal lysates (c and g) from control- and rapamycin-treated mice; b, d, f, h. Quantitative densitometric analyses. Phosphorylated (activated) p70 and phosphorylated 4EBP (b and d), but not S473 phosphorylated PKB/Akt nor phosphorylated PKCalpha (f and h) were decreased in brains of rapamycin-fed mice (P as indicated, unpaired Student’s t test, n=6-10 for each group). Mice were fed with rapamycin-supplemented chow for 16 weeks. i-j. Rapamycin-fed mice C57BL/6J show improved spatial learning and memory. i. Spatial training. Mean latencies to reach a hidden platform were significantly reduced for rapamycin-fed male mice compared to control-fed animals (Significant effect of treatment on performance, F(3,54)=6.40, P as indicated, two-way ANOVA). j. Probe trial. Retention of the former platform site was enhanced in rapamycin-fed male mice with respect to the control-fed group (P as indicated, one-way ANOVA). n=10 for each group. Mice were fed with rapamycin-supplemented chow for 16 weeks. k. Old rapamycin-fed mice show improved memory of an aversive stimulus. Latencies to enter a dark compartment were increased as a result of enhanced memory of an aversive event (2-second foot shock) in rapamycin-fed mice of mixed gender at 25 months of age (P as indicated, upaired Student’s t test). n=9-14 for each group. Data are means ± SEM.

a. Percent time spent engaged in thigmotactic swimming was significantly reduced in male rapamycin-fed mice. b. Percent time spent in thigmotactic swimming on the first day of training was indistinguishable between the two experimental groups; percent time of thigmotaxis decreased significantly as training progressed for both groups [significant effect of day number on thigmotaxis, F(3,54)=14.12; P<0.0001, two-way ANOVA]. Rapamycin-fed mice spent less times swimming close to the tank wall at all times during training (P as indicated, Tukey’s post-hoc test applied to a significant effect of day number on thigmotaxis as above, n=10 for each group). c. Swim traces for day 4 trials (3 representative swim traces are shown for each experimental group; Top panel, control-fed; Lower panel, rapamycin-fed mice). Mice were fed with rapamycin-supplemented chow for 16 weeks. d. Elevated plus maze. Fourteen month-old mice fed with rapamycin for 40 weeks spent less time in the closed arms of the elevated plus maze, indicating decreased anxiety (F(1,45)=7.06; P as indicated, two-way ANOVA). n=11-14 for each group. e-f. Decreased depressive-like behavior in rapamycin-fed mice. e. Floating. Percent time spent floating was significantly lower [F(2,75)=3.3, P=0.04, two-way ANOVA] for rapamycin-fed 8 month-old male mice as compared to control-fed animals (P as indicated, unpaired Student’s t test, n=10 for each group). Mice were fed with rapamycin-supplemented chow for 16 weeks. f. Tail suspension test. Both young (4 month-old) and adult (12 month-old) mice fed with rapamycin for 16 and 40 weeks respectively spent less time immobile when suspended from their tails, indicating that rapamycin treatment reduces depressive-like behavior [F(1,83)=7.26; P as indicated, two-way ANOVA). n=10-16 for each group. Data are means ± SEM.

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.