Effects of physical exercise on central nervous system functions: a review of brain region specific adaptations

Abstract

Pathologies of central nervous system (CNS) functions are involved in prevalent conditions such as Alzheimer's disease, depression, and Parkinson's disease. Notable pathologies include dysfunctions of circadian rhythm, central metabolism, cardiovascular function, central stress responses, and movement mediated by the basal ganglia. Although evidence suggests exercise may benefit these conditions, the neurobiological mechanisms of exercise in specific brain regions involved in these important CNS functions have yet to be clarified. Here we review murine evidence about the effects of exercise on discrete brain regions involved in important CNS functions. Exercise effects on circadian rhythm, central metabolism, cardiovascular function, stress responses in the brain stem and hypothalamic pituitary axis, and movement are examined. The databases Pubmed, Web of Science, and Embase were searched for articles investigating regional brain adaptations to exercise. Brain regions examined included the brain stem, hypothalamus, and basal ganglia. We found evidence of multiple regional adaptations to both forced and voluntary exercise. Exercise can induce molecular adaptations in neuronal function in many instances. Taken together, these findings suggest that the regional physiological adaptations that occur with exercise could constitute a promising field for elucidating molecular and cellular mechanisms of recovery in psychiatric and neurological health conditions.

Keywords: Basal nuclei; Brain stem; Depression; Disease; Exercise; Hypothalamus; Neurobiology; Neurodegenerative Diseases; Neurophysiology; Stress.

Figure 1

Flow diagram of included studies (adapted from [24]).

Figure 2

Effects of voluntary exercise in the brain stem, hypothalamus, and basal ganglia. Legend: Δ = no change; BDNF mRNA = brain derived neurotrophic factor mRNA; c-fos = protein induced acutely by several factors including cytokines; COX = cytochrome oxidase, an indicator of brain regional functional activity; CRF = corticotropin releasing factor/hormone; 5HT = serotonin; 5HTT = serotonin transporter; 5HT1A mRNA = serotonin receptor 1A mRNA; 5HT1B mRNA = serotonin receptor 1B mRNA; Δ α1b-ADR mRNA = α1b-adrenergic receptor (α1b-ADR) mRNA; α-synuclein = precursor protein of amyloid; DRN = dorsal raphe nucleus; ER = endoplasmic reticulum; galanin = a regulatory peptide cleaved from preprogalanin; GR = glucocorticoid receptor; H = hypothalamus; HSP72 = heat shock protein 72; mtDNA: nuclear DNA = mitochondrial DNA to nuclear DNA ratio; NOS = nitric oxide synthase; NTS = nucleus tractus solitarii; P = pituitary; preprogalanin = a precursor of galanin; PVN = paraventricular nucleus; BG = basal ganglia; S = striatum; VTA = ventral tegmental area.