A stressed rat will seek a dose of cocaine that is too weak to motivate an unstressed rat. Researchers traced the physiological pathway that links stress and the stress hormone corticosterone to increased dopamine activity and heightened responsiveness to cocaine.
Can marijuana use put offspring at heightened risk for opiate addiction, even if the use stops before the offspring are conceived? Results from a recent NIDA-funded study are consistent with other studies suggesting that a parent’s history of drug use, even preconception, may affect a child’s brain function and behavior.
Dr. Paul E. M. Phillips spoke on “Phasic Dopamine Transmission During Substance Abuse,” describing investigations that he has led into the role of brief, seconds-long bursts of dopamine signaling in addictive processes. Dr. Rita Z. Goldstein spoke on “Targeting the Brain, Cognition, and Motivation for Intervention in Addiction.”
The Scientific Director of NIDA’s Intramural Research Program talks about switching off animals’ compulsive cocaine seeking by optogenetically activating the prefrontal cortex, and the implications of this work for people. In an accompanying podcast, Dr. Bonci walks viewers through experiments that showed that prefrontal cortex activity levels may constitute a simple switch controlling whether or not animals compulsively seek cocaine.
Two recent studies suggest that genotyping may enable clinicians to base therapies on individual patients’ potential responsiveness to opioid drugs’ therapeutic effects and vulnerability to their harmful effects.
A brain response occurs in the nucleus accumbens when rats encounter a cue that they associate with previous cocaine self-administration, but not a cue associated with a pleasurable non-drug experience. Moreover, the response correlates in time and intensity with the animals’ cue-induced relapse to cocaine-seeking.
One of NIDA’s goals is to try to understand the individual differences that contribute to whether or not someone who takes a drug will become addicted to it. Dr. Rutter’s research focuses on three types of differences: Environmental, developmental, and genetic and epigenetic.