Researchers at the University of Malaga have found that a relevant social stimulus reduces interest in cocaine in animals. The team found that when they gave an animal a positive stimulus, like interaction with another animal, the positive influence decreased the first animal's desire for cocaine.
In this study, the researchers used the conditioned place preference conditioning paradigm, which is a standard model used to study positive and negative effects of drugs. The study was set up with multiple compartments that the mice can move between. If the mice spent more time in a drug-paired (cocaine) compartment compared to a saline compartment, a Conditioned Place Preference (CPP) was found to exist. The researchers discovered that after four days, the mice developed a CPP for the drug-paired compartment.
In the next phase of the experiment, the researchers put a positive stimulus—a juvenile mouse—in the same compartment where the mice had been receiving saline.
“We realized that most of the animals preferred spending more time in this social stimulus to exploring the context where they had received cocaine,” explained Patricia Sampedro, researcher and main author of the study. “We carried out the same experiment but using an inanimate object as stimulus -a Rubik's cube- and, this time, we observed that the animals preferred the drug-paired compartment, which means that the social stimulus is in itself a highly relevant component to catch their attention.”
Based on this behavior, the researchers concluded that a positive stimuli can absolutely influence an animal’s desire for a drug. The results of their findings can be found in the Journal of Psychopharmacology. The scientists plan to continue their research by examining if other positive stimuli, like physical exercise, can produce the same behavioral result.