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.
Methamphetamine alters brain structures involved in decision-making and impairs the ability to suppress habitual behaviors that have become useless or counterproductive. The two effects were correlated, indicating that the structural change underlies the decline in mental flexibility.
Ketoprofen, an anti-inflammatory agent commonly prescribed to treat arthritis, reduces neuronal damage in rats that have been exposed to chronic stress and methamphetamine. If this finding of a recent NIDA-supported study extrapolates to humans, anti-inflammatory medications may gain a place in the treatment of methamphetamine addiction.
Researchers have shut down laboratory rats’ compulsive cocaine seeking by stimulating an area of the animals’ prefrontal cortex. The finding raises the possibility that stimulating neurons in this brain area may weaken or break cocaine’s grip on the behavior of people who are addicted to the drug.
A meta-analysis of 13 genome-wide association studies of African Americans’ smoking patterns confirms the significance of genetic variation in region 15q25.1. The analysis also tentatively implicates several genome locations that have not previously been associated with smoking behaviors.
Dr. Marilyn Huestis of NIDA’s Intramural Research Program talks about conducting research on drug effects with human subjects, developing tests to help law enforcement identify drugged drivers, and an assay to help identify children whose prenatal exposure to anti-HIV drugs may put them at risk for adverse developmental outcomes.