Dopamine – a compound present in the body as a neurotransmitter
Everyone knows that physical exercise is one of the hardest new years resolutions to keep up with, but new research has suggested that there could be a scientific reason as to why finding the motivation to exercise can be so difficult
Exercise is probably one of the best things someone can do to keep their body healthy: it can improve one’s overall physical and mental health, it can reduce the risk of getting severe illnesses and it helps to control weight by burning calories. Yet, even with so many benefits, people still lack the motivation to exercise. Lead researcher Alexxai V. Kravitz – of the Diabetes, Endocrinology, and Obesity Branch at the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) – wondered why it is that obese animals have such a hard time doing physical activity, and while doing his research came up with the following hypothesis that a dysfunction in a rodents’ dopamine system might help to explain their lack of physical exercise…
“We know that physical activity is linked to overall good health, but not much is known about why people or animals with obesity are less active. There is a common belief that obese animals don’t move as much because carrying extra body weight is physically disabling. But our findings suggest that assumption does not explain the whole story.”
Additionally, there have been more studies that have made the link between dopamine and obesity. In fact, dopamine is critical for movement, and obesity is associated with a lack of movement, clearly hinting towards a negative correlation between the two.
Another test done by researchers in an attempt to understand the affects of dopamine was by examining dopamine receptors in mice. Through this experiment, it was found that mice on a high fat diet gained significantly more weight than those on a normal diet, but the mice on a high-fat diet moved less before they gained the majority of the weight, which suggests that the extra weight could not have been responsible for the reduced movement. So, to identify what was actually causing the physical inactivity in the mice, the researchers used dopamine signalling to find that D-2 type receptor (D2R) binding, found in the striatum, was reduced in obese mice. When scientists genetically removed D2Rs from the striatum of lean mice to determine if there was a causal link between D2Rs and inactivity, they found that these mice did not gain more weight, despite their physical inactivity. This suggests that although deficits in striatal D2R contribute to physical inactivity in obesity, such inactivity is more “a consequence than a cause of obesity,”
Finally, I will end on a quote from Danielle Friend, first author of the study and former NIDDK postdoctoral fellow, who said that “there are probably other factors involved as well, but the deficit in D2 is sufficient to explain the lack of activity,”
Source used – medical news today.