dopamine system tagged posts

A new study at the Netherlands Institute for Neuroscience has examined how the dopamine system processes aversive unpleasant events.

It is well known that the dopamine system plays a crucial role in motivation, learning and movement. One of the main functions of dopamine is to predict the occurrence of rewarding experiences and the availability of rewards in our environment. In this context, the dopamine system informs our brains about so-called ‘reward prediction errors’ — the difference between received and predicted rewards. Dopamine neurons become more active when a reward occurs unexpectedly or if it is bigger than expected, and they show depressed activity when we receive less reward than predicted...

Japanese macaques are exposed to stress during rank fights. Credit: Konstanze Meindl Hightlights: A putative COMT splice mutant (HT3) was associated with increased cortisol excretion. •This haplotype was widely distributed among males. •Cortisol excretion was inversely correlated with physical aggression. •No correlation between cortisol and social rank was found.

Certain genes, such as the COMT gene, are thought to play a role in determining our stress response. Researchers have now studied this gene in macaques, a genus of Old World monkeys, and for the first time have shown that a specific variant of the gene is associated with higher excretion of the stress hormone cortisol. The gene variant may also influence social rank among the animals.

Animals that live in groups face a vari...