Texas A&M to Give Cocaine to Rats for Decision-Making Research
The five-year grant from the National Institutes of Health will be used to determine “how chronic cocaine administration affects a type of decision making called ‘impulsive choice,’” Setlow explained.
"In a nutshell, we (and that includes rats or humans) prefer large rewards over small rewards. But if we have to start waiting for the large rewards, then the small and instant rewards quickly become more attractive. The longer the delay to the large reward, the more attractive the small reward becomes."
In his experiments, the rats will actually become addicts by choice. They will press a small lever to get a “hit” of cocaine, and Setlow will examine various aspects of decision making by the rats and what long-term mechanisms affect behavior. The “big question” they want to find out is whether the rat has to be a “full-blown” addict or if a small amount of cocaine will do the trick for it to respond differently.
"We will give the rats a choice to make—a small immediate reward, such as a small amount of food, or a larger but delayed reward, like a large amount of food. We will look to see how our cocaine-addicted rats choose compared to rats who have not used cocaine, what brain changes are responsible for these altered choices, and ultimately, whether these changes can be reversed,” Setlow said.
He continued, “Importantly, all of the cocaine use in our rats will happen months before
we start testing their decision-making abilities, so the rats are not on cocaine while they are choosing. We're interested in how that earlier period of cocaine use causes long-term—perhaps permanent—changes in the brain that lead to impulsive decision making."
Information learned from the project could lead to improved treatment for a variety of addictions. Because increased impulsive choices appear to persist long after a drug user has stopped taking drugs, there are high relapse rates that follow even the best currently used addiction therapies, Setlow said.
"What we learn could give us some better answers to these and other big
questions, and hopefully help in the treatment of millions of people who
suffer from substance addiction.”