Figure 8.

A proposed model by which exercise induces Bdnf expression in the hippocampus. Exercise induces lactate synthesis in the muscle. Lactate is transported through the circulation to the brain. In the hippocampus, lactate induces Bdnf expression through SIRT1-dependent induction of PGC1a. PGC1a, in turn, coordinates the increase in Fndc5 expression, which is known to induce Bdnf expression. This induction mediates exercise's positive effects on memory, cognition, and synaptic transmission.