To drive a rat to drink, make it smoke first. Rats dependent on nicotine escalate their drinking more quickly than rats that haven’t been exposed to nicotine, researchers report in the April 15 Journal of Neuroscience. The results help explain why alcohol and tobacco addictions in people often go hand in hand.
After nicotine injections, rats that had previously been exposed to alcohol dosed themselves with more alcohol than rats unexposed to nicotine did. Scientists were able to curb this booziness: Rats injected with a compound that made brain cells ignore nicotine did not boost their intake of alcohol.
The double whammy of nicotine and alcohol dependence may be due to a select group of nerve cells throughout the rat brain that respond to this nicotine-aided drinking, Olivier George of the Scripps Research Institute in La Jolla, Calif., and colleagues found. If a similar response happens in humans, studying these particular nerve cells might ultimately lead to better ways to curb both alcohol and tobacco dependencies, the researchers write.