Reviews To Read – January 3, 2018.
From the NIDA IRP Real World Assessment, Prediction and Treatment Unit.
In this invited commentary, Bill Kowalczyk and I weighed in on a new rat model of addiction developed by Chiara Giuliano in Barry Everitt’s lab at the University of Cambridge. Like other recently developed models of addiction, this one goes beyond the older approach of just letting rats press levers for drug injections. These rats learned that they had to press one lever just to gain access to a second lever that would give them access to drug. By drawing things out across two successively accessed levers—sort of like inserting an “are you sure?” pop-up window in a chain of computer commands—the researchers made it easier to study the phases across which a rat starts merely seeking a drink and then finally decides to take the drink. Oh, and one more thing. Pressing the second lever sometimes gave the rats an electric shock instead of a drink.
With that method in place, the researchers tested a medication intended to break the process of alcohol-seeking at the earliest possible point. Presumably, for a person with an alcohol-use disorder, this would translate into preventing the initial temptation to have a drink, rather than letting the temptation happen but making it easier to put down the drink (as some currently available medications such as naltrexone seem to do).
Bill and I were not 100% convinced that the new, experimental medication was working better in these rats than currently available medications do. We also raised some questions about what the electric-shock punishment really means when the rat gets it instead of alcohol. After all, when a person with a drinking problem buys a drink, the result is first drunkenness, then (often) problems resulting from drunkenness—not problems that arrive immediately instead of drunkenness.
On the whole, however, we liked seeing this comparatively nuanced approach to the study of how rats choose between alcohol and safety from punishment, and the attention paid to how rats (like people) differ from each other in what they’re willing to risk. With some tweaking, this set of methods could be a nice screening tool for potential treatments.