Researchers at the Baylor College of Medicine discovered that rats exposed to nicotine increased their alcohol consumption and experienced a decrease in their alcohol-induced dopamine responses.
“Our findings indicate the mechanisms by which nicotine influences the neural systems associated with alcohol abuse, providing a foundation for conceptualizing strategies aimed at diminishing the link between smoking and later alcohol abuse,” sais senior author John Dani, of the Baylor College of Medicine.
Investigators also found that rats exposed to nicotine subsequently sought to drink alcohol more often than other rats. When the animals did drink, signaling in the brain’s reward system was dampened.
According to researchers, this decreased reward response to alcohol arose via two mechanisms: an initial activation of stress hormone receptors and a subsequent increase in inhibitory signaling in the brain. These processes were responsible for causing the rats to self-administer more alcohol after nicotine exposure.
Exposure to nicotine at an early age might lead to greater vulnerability to alcohol abuse later in life, according to researchers.
“Therefore, greater vigilance is called for to prevent the initial exposure to nicotine and to follow those at risk,” said Dani. “In addition, our work suggests that stress hormones are candidate targets for prevention or treatment therapies.”