Building And Breaking Connections: How Neuronal Networks Influence Alcoholism
Source: Texas A&M University
Summary: According to a new study, researchers found that alcohol-seeking behavior may be induced by altering the strength of connections between particular neurons.
About 15.1 million American adults have alcohol use disorder, meaning they cannot stop drinking despite adverse consequences, in other words, they have what is commonly referred to as alcoholism. Although it has been known that alterations in the connections between neurons in the brain likely play a role in alcohol dependence and other addictions, the cause-and-effect between these brain alterations and behavior has been less clear. Researchers from the Texas A&M University found that by applying a long-term potentiation protocol to animal models, could directly induce a persistent change in their drinking behavior. The study results indicated that alcohol-seeking behavior may be induced by altering the strength of connections between particular neurons. The research findings were published in the journal Nature Neuroscience.
The research team mimicked the effect of alcohol with optogenetics, in which specially implanted proteins sensitive to light can be rapidly turned on and off within the brain. This process stimulates neuronal activity and essentially recreates the learning and memory that comes from actually performing an activity. Either way, it results in changes to the strength of synapses. But what is more exciting, the team were able to reverse the alcohol-mediated synaptic strengthening by reversing the process. They did so with the opposite of long-term potentiation, what they call long-term depression and decreased drinking behavior. These changes affected particular neurons called D1 (tells the brain to keep drinking) and D2 (tells the brain to stop drinking). Although using this exact process in a human brain wouldn’t be feasible now, the results indicate possible targets for drugs or other therapies in the future.
Asst. Prof Jun Wang said, “Our results provide pretty solid evidence that there is indeed a cause-and-effect relationship between the long-term synaptic changes and alcohol-seeking behavior”, “Essentially, when brain changes are reversed, an individual may not want to drink for a long time.”
More Information: Tengfei Ma et al, “Bidirectional and long-lasting control of alcohol-seeking behavior by corticostriatal LTP and LTD”, Nature Neuroscience (2018). DOI: 10.1038/s41593-018-0081-9