"Curiously, different RhoGAP18B transcripts, RA and RC, regulate the stimulant and sedating effects of ethanol, respectively," the researchers said. While the exact mechanisms underlying these distinct effects remain uncertain, "our data clearly show that Rho-type GTPases are intimately involved in the regulation of behavioral responses to ethanol exposure, thus implicating actin dynamics in the process."

Di Fiore said his group will next sequence human DNA samples in search of evidence that Eps8 variants might play a role in alcoholism. If that hypothesis is borne out, drugs that moderate the cytoskeleton might offer a new method for treating addiction, he suggested.