SIRT1 modulates Bdnf expression through induction of PGC1a protein levels. A, Representative Western blot image depicting the increase in PGC1a protein levels in the hippocampus of control animals compared with exercising mice. B, Quantification of the PGC1a Western blot. *p < 0.05 (unpaired t test; p = 0.05, df = 4). C, Representative Western blot image depicting the increase in PGC1a protein levels in the hippocampus of mice receiving 117 mg/kg of lactate compared with mice receiving saline. D, Quantification of the PGC1a Western blot. *p < 0.05 (unpaired t test; p = 0.0436 and df = 4). E, Representative Western blot image depicting the increase in PGC1a protein levels in primary neurons treated with lactate (20 mm) and the reversal of this increase upon Sirt inhibitor (sirtinol 50 μm) cotreatment. These results suggest that the lactate-mediated induction of PGC1a protein levels is SIRT1-dependent. F, Quantification of the PGC1a Western blot. *p < 0.05 (one-way ANOVA followed by the Dunnett's post-test; p = 0.0007 for control vs lactate, p = 0.002 for lactate + sirtinol versus lactate). **p < 0.01; ***p < 0.001.