Project Summary

Paul J. Kenny, Ph.D. (Young Investigator 2004) of The Scripps Research Institute, notes that depressed patients may have anhedonia, a decreased capacity to experience previously pleasurable and rewarding activities, because of problems with brain reward circuitries. In the proposed project, Dr. Kenny aims to study reward circuitry in mice by employing intracranial self-stimulation (ICSS), which involves implantation of a stimulating electrode in the animal’s brain reward circuits. From this electrode, it is possible to obtain a minimum “threshold” current that the mouse finds rewarding, and will press a lever to obtain. A decrease in reward circuitry function results in an elevation of ICSS thresholds, meaning more current is required to activate brain reward circuits. Conversely, increased function of reward circuits lowers ICSS thresholds. Dr. Kenny plans on using the ICSS procedure to study brain reward function in genetically modified mice missing the metabotropic glutamate 5 receptor, which has been implicated in regulating brain reward circuitry. Such mice offer unique ways to investigate the pathology of depression.

Program Area: MOOD DISORDERS\Unipolar Depression

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