By Mia De Graaf
Original Source: www.dailymail.co.uk
No one ever seems to go for ‘just one drink’.
And scientists claim to have discovered the reason why.
According to a new study, the human brain contains particular neurons, called D2, that tell us to stop drinking.
But problematically, D2 neurons tend to become deactivated when we drink too much alcohol, the Texas A&M Health Science Center College of Medicine study concludes.
This deactivation means we drink more, in a self-perpetuating cycle.
And according to lead author Professor Jun Wang, binge drinking balanced out by a dry spell only serves to weaken these neurons.
However, researchers hope the findings could provide insight into another mechanism underlying the complicated disease of alcoholism, leading to more specific targeted treatment.
By activating particular neurons, scientists may be able to influence drinking behavior.
‘At least from the addiction point of view, D2 neurons are good,’ said Jun Wang, the corresponding author on the paper and assistant professor in the Department of Neuroscience and Experimental Therapeutics at the Texas A&M College of Medicine.
‘When they are activated, they inhibit drinking behavior, and therefore activating them is important for preventing problem drinking behavior.’
The study backed by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) comes after Dr Wang identified another neurons, called D1, which incite cravings.
The previous study, published in September 2015, found alcohol consumption alters the physical structure and function of neurons, called medium spiny neurons, in the dorsomedial striatum.
Essentially, they found that activation of one type of neuron, called D1, determines whether one drink leads to two.
Each neuron has one of two types of dopamine receptors – D1 or D2 – and so can be thought of as either D1 or D2 neurons.
Each neuron has one of two types of dopamine receptors – D1 or D2 – and so can be thought of as either D1 or D2 neurons. D1 neurons incite alcohol cravings, whereas D2 neurons tell us to stop drinking
D1 neurons are informally called part of a ‘go’ pathway in the brain. Therefore, they are the ones that incite alcohol cravings.
D2 neurons, meanwhile, are in the ‘no-go’ pathway, meaning that when D2 neurons are activated, they discourage action – telling you to do nothing.
Dr Wang and his team tested the theory on animals.
They found that in animal models, repeated cycles of excessive alcohol intake, followed by abstaining from alcohol, changed the strength of these neuronal connections.
In others words, regular binge drinking separated by dry spells actually trained the brain to crave drinking.
‘Think of the binge drinking behavior of so many young adults,’ Wang said.
‘Essentially they are probably doing the same thing that we’ve shown leads to inhibition of these so-called “good” neurons and contributes to greater alcohol consumption.’