Dr. Michel Barrot, assistant professor of psychiatry at UT Southwestern and lead author of the paper, said researchers used genetically altered mice to show that pain both physiological and psychological as well as pleasure can activate changes in the nucleus accumbens, the forebrain structure critical for reward and motivation processes. The findings appeared in a recent issue of Proceedings of the National Academy of Sciences.
Senior author Dr. Eric Nestler, chairman of psychiatry at UT Southwestern, had previously established that drugs of abuse activate CREB, a specific binding protein known for playing a role in the plasticity and adaptation of nerves in the nucleus accumbens. This action between a drug and a binding site is involved with the learning processes and can affect the interaction between subject and environment.
Barrot worked with Nestler on the earlier research that laid the scientific basis for the study in Proceedings.
Researchers reported that they used viral-mediated gene transfer to deliver and overexpress CREB locally, thus mimicking the CREB hyperactivity seen after the delivery of drugs of abuse or exposure to stress. The mice were then tested for their sensitivity to rewards, such as morphine or sucrose, as well as for their sensitivity to anxiety-causing negative situations or painful stimuli.
"In the paper we show that inducing local CREB hyperactivity decreases the emotional response of an animal in different ways, including those that are rewarding, aversive, anxiety-provoking or hurtful," Barrot said. "On the other hand, a decrease in activ
Contact: Ann Harrell
UT Southwestern Medical Center