Scientists made a compelling discovery about the neurons in our brains that fuel addiction, and the finding could potentially lead to better cures in the future.
Basically, there are two types of drinkers in this world: ones that can go out and have a casual beer, and others who go out for a drink, but somehow, it always escalates into five. What makes it so difficult to abstain from having “just one more”? Scientists are finally unraveling the mystery of the brain’s alcohol-chasing tendencies.
According to new research at Texas A&M University, alcohol consumption alters the structure and function of neurons in the region of the brain that plays a huge role in goal-driven behaviors. The group of neurons, called D1, are part of the “go” pathway in the brain. So when alcohol activates the “go” neurons, it switches on the part of the brain that makes you want to act — in this case, causing you to crave more booze.
On the opposite side of the spectrum, the alcohol could activate a different type of neurons called D2, which are part of the “no-go” pathway. The D2 neurons have the opposite effect on the brain, telling you to stop drinking.
For a little neuroscience background, there are two kinds of neurotransmitters in the brain (inhibitory and excitatory) that alter the behavior of neurons including D1 and D2. You’ve probably already guessed their effects from the names. Excitatory neurotransmitters stimulate neurons while inhibitory neurotransmitters calm neurons and create balance. When drugs and alcohol are consumed, an excitatory neurotransmitter called dopamine is released in the brain, which is well known to contribute to addiction. The scientists wondered what role the D1 and D2 neurons play in the development of addiction.
To find out, the research team used fluorescent light to study these neurons in mice. While dopamine alone strongly reinforces drug use by providing the euphoric reward of commonly abused drugs, the research shows that the D1 receptor also plays a part in fueling the addiction. The more alcohol the lab mice consumed, the more excitable the D1 neurons became, eventually requiring less dopamine to fire. Thus, a vicious cycle is created — booze consumption makes a neuron more sensitive, which in turn increases the craving to drink.
After making this discovery, the researchers wanted to dig deeper and see what would happen in the brain if specific neurons were blocked. In this case, the mice were given a drug to partially block the D1 receptor, which significantly reduced the desire to drink.
“If we suppress this activity, we’re able to suppress alcohol consumption,” said Jun Wang, the study’s lead author and assistant professor in the Department of Neuroscience and Experimental Therapeutics at Texas A&M. “This is a major finding. Perhaps in the future, researchers can use these findings to develop a specific treatment targeting these neurons.”
By better understanding the way addiction forms in the brain, researchers will have the potential to create more effective cures for it. “My ultimate goal is to understand how the addicted brain works,” Wang says. “And once we do, one day, we’ll be able to suppress the craving for another round of drinks and ultimately, stop the cycle of alcoholism.”