Figure 3.

Lactate induces exercise-dependent Bdnf pI and activity-dependent gene expression in mouse primary neurons. A, Intraperitoneal injection of lactate (117 mg/kg) significantly induces cortical Bdnf pI but not pIV or coding expression levels as measured by real-time RT-PCR. The expression was analyzed from the hippocampi of 4 control mice, 4 mice receiving 117 mg/kg lactate. *p < 0.05 (unpaired t test; p = 0.036, df = 6 for lactate 117 mg/kg vs control). B, Lactate significantly induces Bdnf pI expression in primary hippocampal neurons as measured by real-time RT-PCR. **p < 0.01 (unpaired t test; p = 0.0073 and df = 9 for lactate 20 mm vs control). n = 5. Each replicate consisted of primary neurons obtained from different cultures and treated with fresh dilutions of the compounds for 1 h. C, Lactate significantly induces Bdnf pI and activity-dependent gene (Arc and Zif268) expression in primary cortical neurons as measured by real-time RT-PCR. **p < 0.01 (unpaired t test; Bdnf pI, p = 0.0014 and df = 4 for lactate 20 mm vs control; Arc, p = 0.0014 and df = 5 for lactate 20 mm vs control; Zif268, p = 0.0039 and df = 6 for lactate 20 mm vs control). n = 4. Each replicate consisted of primary neurons obtained from different cultures and treated with fresh dilutions of the compounds for 1 h. D, E, Representative Western blot images depicting the lactate-mediated increase in BDNF, ZIF268, and ARC protein levels in mixed (cortical and hippocampal) primary neurons. F, Quantification of the BDNF Western blots. *p < 0.05 (unpaired t test; p = 0.0199, df = 4). G, Quantification of the ZIF268 Western blots. *p < 0.05 (unpaired t test; p < 0.0001, df = 2). H, Quantification of the ARC Western blots. *p < 0.05 (unpaired t test; p = 0.0483, df = 4). ***p < 0.001; ****p < 0.0001.