A new study on the effects of alcohol on learning and memory has found that repeated exposure to alcohol enhances synaptic plasticity in areas of the brain that control our capacity to learn. Put simply, this suggests that with repeated drinking, the brain creates subconscious memories that are associated with alcohol, and thus creates alcohol cravings.
Neurobiologist Hitoshi Morikawa, lead author of the study, said that most people think alcohol only affects conscious memory, such as remembering the definition of a word or where your car is parked, but in fact, the subconscious memory is affected as well, and that alcohol may increase the brain’s capacity to “learn” certain habits. The new study adds to a growing body of evidence that addiction is a learning and memory disorder.
When a person drinks alcohol or uses any addictive substance, his or her subconscious learns to consume more of that substance. The brain also becomes more receptive to forming subconscious memories and habits regarding small details, such as food, music, people, and social situations.
Morikawa said that people aren’t really addicted to the pleasure they get from drinking alcohol, but instead to the environmental, behavioral, and psychological cues that are reinforced every time alcohol is consumed.
Substances like cocaine and alcohol release a flood of dopamine, a neurotransmitter that is associated with feelings of pleasure, in the brain. Morikawa said that people usually think of dopamine as a “happy transmitter,” but it’s actually a “learning transmitter,” because it enforces the synapses that are activated upon the release of dopamine.
In this scenario, alcohol takes over the dopamine system and tells the brain that drinking is rewarding, and thus worth repeating. When a person drinks repeatedly, the brain learns that all the things that are associated with drinking (such as friends, bars, certain foods, and certain music) are also rewarding, and associates those cues to alcohol. The more often a person does these things while drinking (and the more dopamine is released), certain synapses are strengthened and the brain craves the set of experiences that are associated with drinking.
Morikawa hopes that by deepening his understand of the neurobiological foundation of addiction, he can develop medication that will help people suffering from alcohol abuse and alcoholism. The medication would weaken, rather than strengthen, key synapses, which would weaken the subconscious memories associated with addiction.
Source: Science Daily, Can Alcohol Help the Brain Remember? Repeated Ethanol Exposure Enhances Synaptic Plasticity in Key Brain Area, Study Finds, April 12, 2011