Abstract
BACKGROUND: Recent studies have shown that the endocannabinoid system has a positive effect on the release of dopamine in the limbic cortex, and the reward mechanism of dopamine is a key factor influencing exercise motivation.
OBJECTIVE: To systematically investigate the composition of the endocannabinoid system and its important role in neurotransmitter regulation, emotion regulation and pain perception, and to focus on exploring how the endocannabinoid system promotes the improvement of exercise motivation through the dopamine reward system, signal integration in motor control regions and fatigue recovery mechanism.
METHODS: Computerized searches were conducted in CNKI, WanFang, VIP, PubMed, MedReading and Web of Science databases The search terms included “endocannabinoid system, exercise motivation, dopamine reward system, neuromodulation, cannabinoid receptor, anandamide, 2-arachidonoylglycerol” in Chinese and English. According to the inclusion and exclusion criteria, 84 articles were finally included for review.
RESULTS AND CONCLUSION: This study reveals the significant role of the endocannabinoid system in promoting exercise motivation. (1) In the reward pathway, the endocannabinoid system acts on the mesolimbic dopamine pathway and stimulates dopamine release through downstream cannabinoid type 1 receptors, thereby enhancing the rewarding effect of the dopaminergic pathway and ultimately increasing the pleasure during exercise. (2) In terms of motor control, the endocannabinoid system achieves an optimal state by regulating synaptic plasticity changes in the ventromedial prefrontal cortex, and it precisely transmits signals to the striato-cortical circuit through spatial positioning to maintain the stability of exercise motivation. Moreover, the anti-inflammatory mechanism mediated by cannabinoid type 2 receptors can protect the nervous system from damage by inhibiting the excessive activation of microglial M1 polarization. (3) In terms of fatigue recovery, the endocannabinoid system, on the one hand, alleviates post-exercise discomfort and reduces fatigue caused by exercise by inhibiting the body’s pain receptors through cannabinoid type 1 or type 2 receptors. On the other hand, it can increase the plasticity of brain neurons and improve the structure of muscle fibers through the action of anandamide-brain-derived neurotrophic factor to help restore physical strength quickly. In conclusion, targeting the endocannabinoid system can effectively enhance people’s desire to engage in sports activities, , which has important clinical value and significance, especially for those who have not participated in physical exercise for a long time or those suffering from depression. However, more experimental evidence is needed to support this conclusion.