Brain changes caused by stroke may lead to an increase in alcohol-seeking behaviour, an animal study has showed.
The findings revealed that stroke kills neurons in a part of the brain called the dorsal lateral striatum, and they stop inhibiting certain neurons in the mid-brain.
These mid-brain neurons, which are now far more excitable, send a signal to a particular type of dopamine receptor, called D1 — which compels an individual to perform an action like having an alcoholic beverage.
“This circuit is interesting because it means that when the dorsal lateral striatum neurons die, the result is increased excitement of the D1 neurons in the dorsomedial striatum,” said Jun Wang, Assistant Professor at the Texas A&M University.
“It is this increased excitement that we think is causing alcohol-seeking behaviour,” Wang added.
In the study, published in the journal Scientific Reports, after the animal models suffered an ischemic stroke in the middle cerebral artery — one of the most common types of stroke in humans — they showed much lower overall fluid intake but increased preference for alcohol over water when they did drink.
“Their preference for alcohol can be seen five days after stroke and through at least the first month after the stroke,” Wang said.
“Specifically, when given a choice between water and alcohol, they chose alcohol a higher percentage of the time than they did before the stroke,” he added.
However, when the D1 receptor was inhibited, alcohol-seeking behaviour in individuals with stroke damage decreased significantly, while the control group did not exhibit much of a change.
“This is a hint at how the brain works. Something to inhibit this D1 receptor might be a possible therapeutic target for a drug to help people resist the urge to drink after a stroke,” Wang said.