Neuron Responsible for Alcoholism Found

Amy Taylor September 04, 2015

Research published in the Journal of Neuroscience points out the population of neurons in the brain which could predict a person’s tendency to engage in alcoholism. The new findings, according to the researchers, are an important step towards developing treatments that target this form of substance abuse.

"Alcoholism is a very common disease," says lead author Jun Wang, M.D., Ph.D. He and his team found that alcohol actually changes the physical structure of medium spiny neurons - the main type of cell in the striatum. Neurons can be thought like a tree, the researchers explain. They have many branches, spines and protrusions coming off them. They each have one of two types of dopamine receptors, D1 or D2, and so can be thought of as either D1 or D2 neurons. D1 neurons are informally called part of a "go" pathway in the brain, while D2 neurons are in the "no-go" pathway. In other words, when D2 neurons are activated, they discourage action—telling you to wait, to stop, to do nothing.

The team found that periodic consumption of large amounts of alcohol acts on D1 neurons, making them much more excitable, which means that they activate with less stimulation.

"If these neurons are excited, you will want to drink alcohol," Wang explained. "You’ll have a craving." That is to say, when neurons with D1 receptors are activated, they compel you to perform an action—reaching for another bottle of tequila, in this case. This then creates a cycle, where drinking causes easier activation, and activation causes more drinking.”

"When you drink alcohol, long-term memory is enhanced, in a way," Wang said. "But this memory process is not useful—in fact, it underlies addiction since it affects the ’go’ neurons." Because there was no difference in the number of each type of spine in the D2 (no-go) neurons of alcohol-consuming and control models, the researchers realized there was a specific relationship between D1 neurons and alcohol consumption.

The research was co-authored by scientists from the University of California San Francisco.

Source of this article: Alcohol Elicits Functional and Structural Plasticity Selectively in Dopamine D1 Receptor-Expressing Neurons of the Dorsomedial Striatum