Regulation of Voluntary Physical Activity Behavior: A Review of Evidence Involving Dopaminergic Pathways in the Brain

Abstract

Physical activity leads to well-established health benefits. Current efforts to enhance physical activity have targeted mainly socioeconomic factors. However, despite these efforts, only a small number of adults engage in regular physical activity to the point of meeting current recommendations. Evidence collected in rodent models and humans establish a strong central nervous system component that regulates physical activity behavior. In particular, dopaminergic pathways in the central nervous system are among the best-characterized biological mechanisms to date with respect to regulating reward, motivation, and habit formation, which are critical for establishing regular physical activity. Herein, we discuss evidence for a role of brain dopamine in the regulation of voluntary physical activity behavior based on selective breeding and pharmacological studies in rodents, as well as genetic studies in both rodents and humans. While these studies establish a role of dopamine and associated mechanisms in the brain in the regulation of voluntary physical activity behavior, there is clearly need for more research on the underlying biology involved in motivation for physical activity and the formation of a physical activity habit. Such knowledge at the basic science level may ultimately be translated into better strategies to enhance physical activity levels within the society.

Keywords: dopamine; exercise; habit; motivation; neurobiology.

Figure 1

Dopamine Pathways. Dopaminergic neurons originating from the ventral tegmental area (VTA) project to the nucleus accumbens (NAc), amygdala, hippocampus, and prefrontal cortex (PFC) and are referred to as the mesocorticolimbic DA pathway. Dopaminergic neurons originating from the substantia nigra pars compacta (SNc) project primarily to the dorsal striatum and are referred to as the nigrostriatal DA pathway.

Figure 2

Genetic regulation of voluntary physical activity through dopamine pathways in the brain. A proposed model depicting genetic evidence-based potential biological mechanisms involved in the regulation of motivation for physical activity via dopamine-associated pathways (see text for explanation of genes shown; arrow head indicates procession, with the size of the arrow representing degree of procession; T head indicates inhibition/reduction).