Molecular Functions of BDNF
BDNF binds to TrkB receptors, activating intracellular signaling cascades (MAPK/ERK pathway, PI3K/Akt pathway). This promotes long-term potentiation (LTP), strengthening the molecular basis of learning and memory. In the hippocampus, BDNF is described as encouraging neural stem cell proliferation and differentiation, supporting new neuron generation (neurogenesis). This pathway comes mainly from rodent research, and its extent in adult humans remains a matter of differing views as of August 2026. For the prefrontal cortex, it is thought to help maintain dendritic spine density and protect synaptic connections underlying executive function, though this too rests mainly on animal research.
Relationship Between Exercise and BDNF
Aerobic exercise is widely cited as a factor that promotes BDNF secretion. Sustained moderate-intensity exercise is reported to raise blood BDNF shortly after the session, with levels then returning gradually toward baseline. Higher intensity is noted to produce a larger acute elevation, but which intensity best supports a long-term increase in baseline secretion is unsettled as of August 2026. Irisin released from skeletal muscle during contraction is also examined as a route involved in brain BDNF expression.
BDNF and Cognitive Performance
A positive association between blood BDNF concentration and cognitive test scores has been reported, most often in memory and executive function tasks. MRI studies of older adults who kept up aerobic exercise have also reported differences in hippocampal volume, and their relationship to BDNF-mediated pathways is under discussion (intervention length and the size of the change differ across studies). Acute BDNF elevation from pre-test exercise is examined as a possible route to feeling more focused, though effects on test scores vary widely between individuals.