At the molecular level, drugs like salvinorin A (the active ingredient of the hallucinogenic plant Salvia divinorum ) work by activating specific proteins, known as receptors, in the brain and body. Salvinorin A, the most potent naturally occurring hallucinogen, is unusual in that it interacts with only one receptor in the human brain - the kappa opioid receptor (KOR). Scientists know of four distinct types of opioid receptors, but until now the structure of the 'salvia receptor', and the details about how salvinorin A and other drugs interact with it, was a mystery. In a research paper published in the journal Nature, scientists from the University of North Carolina at Chapel Hill, Scripps Research Foundation and two other institutions revealed the first-ever glimpse of the complete structure of the KOR.
Anxiety, depression, stress and social support can predict early alcohol and illicit drug use in youth, according to a study from Carolyn McCarty, PhD, of Seattle Children's Research Institute, and researchers from the University of Washington and Seattle University. Middle school students from the sixth to the eighth grade who felt more emotional support from teachers reported a delay in alcohol and other illicit substance initiation. Those who reported higher levels of separation anxiety from their parents were also at decreased risk for early alcohol use. The study, "Emotional Health Predictors of Substance Use Initiation During Middle School, " was published in advance online in Psychology of Addictive Behaviors. Relatively few studies have examined support for youth from nonfamily members of the adolescent's social support network, including teachers.
A major downside of the medical use of marijuana is the drug's ill effects on working memory, the ability to transiently hold and process information for reasoning, comprehension and learning. Researchers reporting in the March 2 print issue of the Cell Press journal Cell provide new insight into the source of those memory lapses. The answer comes as quite a surprise: Marijuana's major psychoactive ingredient (THC) impairs memory independently of its direct effects on neurons. The side effects stem instead from the drug's action on astroglia, passive support cells long believed to play second fiddle to active neurons. The findings offer important new insight into the brain and raise the possibility that marijuana's benefits for the treatment of pain, seizures and other ailments might some day be attained without hurting memory, the researchers say.
Researchers from Boston University Schools of Medicine (BUSM) and Public Health along with Boston Medical Center have found children's academic achievement test scores not affected by intrauterine exposure to cocaine, tobacco or marijuana. However, alcohol exposure in children who had no evidence of fetal alcohol syndrome (FAS) did lead to lower scores in math reasoning and spelling even after controlling for other intrauterine substance exposures and contextual factors. These findings currently appear on-line in the journal of Vulnerable Children and Youth Studies. There has been widespread concern that intrauterine cocaine exposure (IUCE) may have harmful effects on children's academic performance, particularly at higher grades requiring abstract reasoning and greater attention and control.
Light-to-moderate alcohol consumption has been consistently associated with lower risk of heart disease, but data for stroke are less certain, especially among women. A total of 83, 578 female participants of the Nurses' Health Study who were free of diagnosed cardiovascular disease and cancer at baseline were followed-up from 1980 to 2006. Data on self-reported alcohol consumption were assessed at baseline and updated approximately every 4 years, whereas stroke and potential confounder data were updated at baseline and biennially. Strokes were classified according to the National Survey of Stroke criteria. The authors found that the risk of total stroke is significantly lower among light-to-moderate consumers of alcohol than among subjects reporting no alcohol intake. In comparison with non-drinkers, the estimated risk was 17-21% lower for women averaging up to 15 grams of alcohol per day (one drink/day by US definitions of approximately 14 grams of alcohol, or two UK units of 8g).