Exercise has been touted to do everything from treat depression to improve memor
y, with the power to cure a host of problems while preventing even more. In particular, exercise leads to the release of certain neurotransmitters
in the brain that alleviate pain, both physical and mental. Additionally, it is one of the few ways scientists have found to generate new neurons
. Much of the research done in this area has focused on running, but all types of aerobic exercise provide benefits. Although the exact nature of these benefits is still being determined, enough research has been done to provide even skeptics with a motivation to take up exercise. Exercise exerts its effects on the brain through several mechanisms, including neurogenesis, mood enhancement, and endorphin releas
e. This paper not only examines how these mechanisms improve cognitive functioning and elevate mood states, but also proposes potential directions for future research. Furthermore, it provides an explanation for exercise's generally non-habit forming nature, despite effects on the reward centers of the brain that mimic those of highly addictive drugs like morphine.
One of the most exciting changes that exercise causes is neurogenesis, or the creation of new neurons. The new neurons are created in the hippocampus, the center of learning and memory in the brain (1), however the exact mechanism behind this neurogenesis is still being explored. At a cellular level, it is possible that the mild stress generated by exercise stimulates an influx of calcium, which activates transcription factors in existing hippocampus neurons. The transcription factors initiate the expression of the BDNF (Brain-Derived Neurotrophic Factor) gene, creating BDNF proteins that act to promote neurogenesis (17). Thus the generation of BDNF is a protective response to stress, and BDNF acts not only to generate new neuron
s, but also to protect existing neurons and to promote synaptic plasticity (the efficiency of signal transmission
across the synaptic cleft between neurons, generally considered the basis of learning and memory) (1, 3, 17). However, BDNF's effects are more than protective, they are reparative