Sex Hormone Linked to Cocaine Addiction Susceptibility
An animal study released by the University of Texas at Arlington has found that the female sex hormone estradiol—a synthetic version of the naturally occurring estrogen—has been linked with increased susceptibility to cocaine addiction. The finding backs previous research that shows women are more likely than men to develop an addiction to cocaine, try cocaine at a younger age, use larger amounts of the drug, and suffer an overdose.
The study, which was published in the journal Pharmacology Biochemistry and Behavior, was the first to demonstrate the link between estradiol and cocaine.
“Our research fills a significant gap in the knowledge of drug addiction, and it provides a crucial link to understanding how fluctuating hormone levels can cause females to be more sensitive to the rewarding effects of cocaine,” study senior author Linda Perrotti, professor and chair of the Department of Psychology at UTA, said in a news release.
The UTA study used experimentally naïve adult (90 to 120 days old) male and female Long Evans rats that were triple-housed with same-sex cage mates in a climate controlled environment. Using a research technique known as conditioned-place preference—a preclinical behavioral model used to study the rewarding and aversive effects of drugs—UTA researchers observed heightened sensitivity to the acute rewarding effects of cocaine in females, and levels were also found to fluctuate depending on where females were in their reproductive cycles.
“[W]e have established that [estradiol] enhances cocaine-conditioned reward by potentiating cocaine-context associations formed during conditioning,” the researchers wrote. “Additionally, activation of ERK1/2 [the extracellular signal-regulated kinase 1/2] during cocaine-conditioning is necessary for the potentiation of cocaine-conditioned reward by [estradiol].”
References
Buccafusco JJ, Buccafusco JJ. Methods of Behavioral Analysis in Neuroscience. CRC Press; 2009.
