Is it possible that stress can lead to cocaine abuse or is it the other way around? According to the results in recent mouse studies, the stress-evoked changes in circuits that regulate serotonin in certain parts of the brain can precipitate a low mood and a relapse in cocaine-seeking.
Science Daily recently published a release that examined the findings of this study.
“The impetus for this research was our interest in how stress alters the brain’s cell receptors and protein signals in ways that lead to mood changes, depression, anxiety, and drug seeking,” said Dr. Michael Bruchas, acting instructor of pharmacology at the University of Washington (UW). The senior author was Dr. Charles Chavkin, the Allan and Phyllis Treuer Professor of Pharmacology and director of the UW Center for Drug Addiction Research.
This team of researchers explained that the dynorphin/kaapa opioid system that is found in certain brain cells, can be activated either through repeated stress or by giving a chemical that triggers a receptor on the cells. When this system is activated, it creates a conditioned place aversion in mice.
As a result, the mice tend to want to avoid smell, locations or tactile sensations that are similar to those present during a troubling experience. Additional research suggests that this response is medicated by the stress-evoked release of dynorphins, which are considered to be the “feel bad” brain signals.
“Stress appears to be a motivator for the relapse in drug seeking,” said one of the study authors. “They feel crummy so they go where there might be something that will make them feel okay again. They head to a spot that had the drug available in the past, an action researchers call cocaine place preference.”