Introduction: Exercise attenuates inflammation and enhances levels of brain-derived neurotrophic factor (BDNF). Exercise also enhances parasympathetic tone, although its role in activating the cholinergic anti-inflammatory pathway is unclear. The physiological pathways of exercise's effect on inflammation are obscure.
Aims: To critically review the evidence on the role of BDNF in the anti-inflammatory effects of exercise and its potential involvement in the cholinergic anti-inflammatory pathway.
Methods: Critical literature review of studies published in MEDLINE, PubMed, CINAHL, Embase, and Cochrane databases.
Results: BDNF is critically involved in the bidirectional signaling between immune and neurosensory cells and in the regulation of parasympathetic system responses. BDNF is also intricately involved in the inflammatory response: inflammation induces BDNF production, and, in turn, BDNF exerts pro- and/or anti-inflammatory effects. Although exercise modulates BDNF and its receptors in lymphocytes, data on BDNF's immunoregulatory/anti-inflammatory effects in relation to exercise are scarce. Moreover, BDNF increases cholinergic activity and is modulated by parasympathetic system activation. However, its involvement in the cholinergic anti-inflammatory pathway has not been investigated.
Conclusion: Converging lines of evidence implicate BDNF in exercise-mediated regulation of inflammation; however, data are insufficient to draw concrete conclusions. We suggest that there is a need to investigate BDNF as a potential modulator/mediator of the anti-inflammatory effects of exercise and of the cholinergic anti-inflammatory pathway during exercise. Such research would have implications for a wide range of inflammatory diseases and for planning targeted exercise protocols.
Keywords: brain-derived neurotrophic factor; cholinergic anti-inflammatory pathway; critical illness; early progressive mobility; exercise; immunity; inflammation; parasympathetic nervous system; physical activity.
© The Author(s) 2014.