November 2013 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.
January 2014 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.
January 2014 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.
March 2014 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.
April 2014 Exposing rats to THC increases the likelihood that the animals will later self-administer nicotine. THC-exposed rats are also willing to work harder to obtain nicotine. When extrapolated to people, the findings suggest that THC’s pharmacological impact on the brain may make a person who uses marijuana more vulnerable to developing nicotine addiction, an underappreciated health consequence of marijuana use.
May 2014 Driving under the influence of marijuana is a dangerous public health concern. NIDA researchers have discovered that breath expelled into a Breathalyzer-style collection device contained measurable amounts of THC for up to 2 hours after participants in a recent clinical trial smoked the drug.
May 2014 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.
June 2014 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.
July 2014 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.