Training rats to recognize the smells of banana and orange may not seem too exciting to most people, but for alcoholics trying to remain abstinent from alcohol, it could mean the difference between relapse and recovery. Researchers have discovered that "alcohol-related cues" like smell can induce a neurochemical response in the brain that may "reinstate alcohol-seeking behavior" after withdrawal and abstinence. In other words, smells may trigger craving for alcohol, which could lead to relapse.
"Addiction is essentially a chronic relapsing disease of the brain," said Friedbert Weiss, Associate Professor in the Department of Neuropharmacology at The Scripps Research Institute and senior author of the study. "Addiction is a relapsing disorder that, even after successful short-term treatments, has a strong tendency to reoccur." Weiss said there are both biological and 'situational' factors involved in relapse; situational factors that include stress, a particular neighborhood, a piece of music, the sight of a liquor bottle, a bar environment, or the smell of alcohol.
"Evidence suggests that all drugs, including alcohol, increase dopamine levels in a part of the brain known as the nucleus accumbens," said Simon N. Katner, Senior Scientist at the Gallo Clinic, University of California and the study's first author. "We wanted to examine if alcohol-associated cues like smell could also alter dopamine levels."
In the study, published in the November edition of Alcoholism: Clinical & Experimental Research, rats were trained to self-administer alcohol or quinine in the presence of particular smells: the smell of alcohol or banana was