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Genetics Glossary

Agonist: An agent that mimics the actions or effects of another agent at a receptor (e.g., a drug that mimics the effects of a neurotransmitter).

Allele: One of two or more forms of a gene that reside at the same position on a pair of chromosomes; different alleles of a gene may serve the same function (e.g., code for an enzyme that breaks down alcohol) but may result in proteins with different...

Genetics Primer

Genetics is the study of genes— the heritable information that contains the codes for proteins and other molecules which form and maintain an organism’s structure and function. In most organisms, these genes are found in strands of deoxyribonucleic acid (DNA) molecules. The specific structure of the DNA (described below) ensures that the genetic information can be passed from one generation to the...

Identifying Genetic Variation for Alcohol Dependence

Over the last decade, three large-scale projects have catalyzed a revolution in genetic technologies and studies. First, the Human Genome Project laid the foundation for modern genetic studies of disease by determining the basic sequence of the 3 billion building blocks (i.e., base pairs) that make up the human genome and by identifying the approximately 25,000 genes included in this sequence (htt...

A Watershed Year for an Update on the Genetics of Alcoholism

It is easy to think of genetics as the study of genes, but given our current knowledge of genetics, this definition is now considered inadequate. Genetics is the study of differences among individuals—even between identical twins. We know that some differences between individuals are linked to variations in DNA sequence (i.e., the genome), but most differences actually are caused by complex...

Immune Function Genes, Genetics, and the Neurobiology of Addiction

The nervous system and the immune system interact closely to regulate the body’s immune responses, including inflammatory responses. Accordingly, the term “neuroimmune system” refers to the immune system and those components of the nervous system that help regulate immune responses and also encompasses the hormones and other signaling molecules that convey signals between the immune and nervous...

Bridging Animal and Human Models: Translating From (and to) Animal Genetics

Alcoholism is a complex disorder arising from a combination of genetic and environmental factors. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM–IV) (American Psychiatric Association 1994) requires that three of seven criteria be present during a 12-month period for a diagnosis of alcohol dependence. These criteria are tolerance, withdrawal symptoms, loss of control...

Genetic and Genomic Web Resources for Research on Alcohol Use and Abuse

There are two major ways of publishing scientific data and results: (1) the standard peer-reviewed paper, which dates back to volume 1 of the Philosophical Transactions of the Royal Society in 1665; and (2) online distribution of data, resources, and software using the Internet that dates back a mere 21 years to the first Web site at the European Organization for Nuclear Research (CERN)...

Using Genetically Engineered Animal Models in the Postgenomic Era to Understand Gene Function in Alcoholism

During the first decade of the new millennium, remarkable advances in technology allowed investigators in all areas of biological research to collect massive amounts of genetic data at an unprecedented rate. The genomics revolution, which began with the sequencing of the human genome, was the basis for efforts such as the 1,000 Genomes Project (http://www.1000genomes.org/) that strive to compile a...

Genetic and Environmental Determinants of Stress Responding

The development of alcohol dependence is a complex process influenced by both genetic and environmental risk factors (Prescott and Kendler 1999). The relative contributions of genetic and environmental influences fluctuate across development. During adolescence the initiation of alcohol use is strongly influenced by environmental factors (Dick et al. 2007; Heath et al. 1997; Karvonen 1995...