Research Highlights

Research News
Friday, September 17, 2010

Web-Based Genetic Feedback Can Help Reduce Alcohol-Related Health Risks

Author: 
John Bowersox

Although genetic feedback has been evaluated as an adjunct to smoking cessation interventions, its efficacy for reducing alcohol-related risks is unknown. The current study evaluated the feasibility, acceptability, and efficacy of a web-based alcohol intervention incorporating genetic feedback and risk information specific to ALDH2 genotype. The ALDH2*2 variant is associated with partial protection against alcohol dependence but confers significantly increased risk for alcohol-related cancers as a function of alcohol exposure. Two hundred Asian-American young adults were randomly assigned to receive web-based personalized genetic feedback or attention-control feedback. Genetic feedback included health risk information specific to alcohol-related cancer or alcohol dependence, depending on genotype. Genetic feedback and risk information resulted in significant reductions in 30-day drinking frequency and quantity among participants with the ALDH2*1/*2 genotype. Genetic feedback was rated highly by participants and also showed some effects on theoretical correlates of behavior change. Results provide initial evidence of the feasibility, acceptability, and brief efficacy of web-based genetic feedback for reducing alcohol-related health risks associated with the ALDH2 genotype. Results also highlight the utility of targeting preventive interventions based on genetically-related risk and protective factors and specific environmental exposures.

Date: 
September 17, 2010
Research News
Friday, September 17, 2010

Moderate Drinking During Pregnancy Alters Gene Expression in the Placenta

Author: 
John Bowersox

Many children adversely affected by maternal drinking during pregnancy cannot be identified early in life using current diagnostic criteria for fetal alcohol spectrum disorder (FASD). In the current study, conducted with pregnant rats, researchers examined whether ethanol-induced alterations in placental gene expression may be useful as diagnostic indicators of maternal drinking during pregnancy and as a prognostic indicators of risk for adverse neurobehavioral outcomes in affected offspring. Analyses of more than 28,000 genes revealed that the expression of 304 known genes was altered twofold or greater in placenta from ethanol-consuming pregnant rats compared with controls. Gene expression changes involved proteins associated with central nervous system development; immunological responses; endocrine function; skeletal, cardiovascular, and cartilage development, as well as other effects. These results suggest that the expression of a sufficiently large number of placental genes is altered after moderate drinking during pregnancy to warrant more detailed investigation of the placenta as a biomarker system for maternal drinking during pregnancy and as an early indicator of FASD. Given the accessibility of placentas following child birth, the gene changes identified in this study have the potential to serve as practical biomarkers of prenatal alcohol exposure and/or predictors of FASD in offspring. In addition, the identity of these genes could inform our understanding of alcohol's effects on placental function.

Date: 
September 17, 2010
Research News
Friday, September 17, 2010

Low Concentrations of Alcohol Inhibit Prenatal Development of Hippocampal Neurons

Author: 
John Bowersox

The learning and memory disabilities associated with fetal alcohol spectrum disorder (FASD) are due, in part, to hippocampal damage caused by ethanol exposure during prenatal development. However, the mechanism by which alcohol damages the developing hippocampus remains poorly understood. In the current study, researchers examined how ethanol exposure in neonatal rats – a period that is developmentally equivalent to the third trimester of pregnancy in humans -- affects neuronal activities in the hippocampus. They report that in vivo and in vitro ethanol exposure potently inhibits molecular processes that are vital for the proper function and maturation of hippocampal neurons. Most importantly, the ethanol effect reaches significance at concentrations that can be achieved by a pregnant woman consuming less than a single standard drink in an hour. Although many other studies have shown effects of ethanol on synaptic function in developing neurons, the study reported here reveals the most potent effect of ethanol to date. It suggests that even low amounts of alcohol consumption during pregnancy may cause irreversible effects on hippocampal neurons and contribute to FASD.

Date: 
September 17, 2010
Research News
Friday, September 17, 2010

Heavy Alcohol Consumption During Adolescence Compromises Hippocampal Development

Author: 
John Bowersox

Binge drinking is common during adolescence, a period of rapid brain development. In this study, researchers used adolescent nonhuman primates to examine the effects of long-term binge alcohol consumption on brain development. They found that an 11-month period of heavy binge alcohol consumption by nonhuman primates led to a significant and persistent reduction in neurogenesis – the birth and maturation of new neurons – in the hippocampus, a brain region involved in learning and memory formation. Alcohol specifically interfered with the division and migration of hippocampal precursor cells. The lasting reduction in hippocampal neurogenesis was paralleled by an increase in neural degeneration. The findings demonstrate that hippocampal development during adolescence is highly vulnerable to alcohol, and suggests that alcohol-induced hippocampal degeneration is one of several factors that may increase the vulnerability to alcohol use disorders.

Date: 
September 17, 2010
Research News
Monday, January 31, 2011

Frontocerebellar abnormalities may signal increased risk for alcohol problems

Author: 
John Bowersox

Brain circuits that connect the frontal lobes with the cerebellum are damaged in chronic alcoholics and may contribute to cognitive deficits in these individuals.  But whether these “frontocerebellar” abnormalities are present in individuals at high risk for alcoholism before they start using alcohol is unknown.  To find out, scientists led by Dr. Megan Herting at the Oregon Health and Science University conducted brain imaging studies with young people whose positive family history for alcoholism put them at high risk for the disease.  Using two different brain imaging techniques -- functional connectivity magnetic resonance imaging and diffusion tensor imaging – the researchers found that family history positive adolescents who had never used alcohol had fewer functional connections between areas of the prefrontal cortex and the cerebellum than did youth with no family history for alcoholism.  The researchers also found that the reduction in functional connectivity was associated with reduced white matter structural integrity in other parts of the frontocerebellar circuitry.  Taken together, the findings suggest that frontocerebellar abnormalities may be a biological marker of risk for alcohol use disorders.

Date: 
January 31, 2011

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