Research Paper Title

Aerobic Exercise Improves Food Reward Systems in Obese Rats via Insulin Signaling Regulation of Dopamine Levels in the Nucleus Accumbens.

Background

The dopaminergic pathway, comprising projections from the ventral tegmental area to the nucleus accumbens, constitutes the core of the brain reward system.

Insufficient food reward caused by dopamine signaling dysfunction in the nucleus accumbens is an important contributor to obesity and may be associated with insulin signaling.

Aerobic exercise has a positive effect on both preventing and treating obesity.

In addition, physical exercise is important in striatal dopamine homeostasis and improves insulin sensitivity in the peripheral and central nervous system.

Therefore, the researchers hypothesised that aerobic exercise may increase dopamine levels in the nucleus accumbens through insulin signaling, thus improving food reward in obesity.

Methods

In the present study, the researchers used a rat model of obesity, induced by a high fat diet.

Results

Obese rats exhibited lower basic dopamine concentration in the nucleus accumbens induced by eating or extracellular insulin, attenuated insulin signalling, and increased fat preference.

Interestingly, an 8-week aerobic exercise regimen reversed these symptoms.

In addition, the researchers noted a significant increase in insulin Akt/GSK3-β signal transduction in the nucleus accumbens.

Conclusions

These data demonstrate that aerobic exercise promotes dopamine levels in the nucleus accumbens through insulin signal transduction, which may constitute an important neurobiological mechanism of exercise against obesity.

Reference

Chen, W.1, Li, J., Liu, J., Wang, D. & Hou, L4. (2019) Aerobic Exercise Improves Food Reward Systems in Obese Rats via Insulin Signaling Regulation of Dopamine Levels in the Nucleus Accumbens. ACS Chemical Neuroscience. 10(6), pp.2801-2808. doi: 10.1021/acschemneuro.9b00022. Epub 2019 May 1.