Striatal dopamine D2 receptor expression, physical activity, and weight gain

Monday, September 22, 2014 — Poster Session I
12:00 p.m. – 2:00 p.m.	FAES Academic Center	NIDDK	NEURO-6

* FARE Award Winner

Authors

• K. Devarakonda
• D.M. Friend
• K.D. Hall
• A.V. Kravitz

Abstract

Striatal dopamine D2 receptor (D2R) function has been linked to obesity. Striatal D2Rs exert inhibitory control over indirect pathway medium spiny neurons (iMSNs), which inhibit movement when stimulated. Therefore we hypothesized that reduced D2R expression on iMSNs reduces movement, which may lead to obesity. To test this hypothesis, male C57BL/6 mice were placed on a long-term high-fat diet, alongside weight-matched controls that remained on chow. Food intake, body composition, and physical activity were periodically measured in both groups. Striatal expression of D2R was assessed at various time points during the diet with D2R autoradiography. On the high-fat diet, mice consumed more calories and gained more weight and body fat, compared to the chow controls. Additionally, the high-fat diet mice reduced their physical activity in both the open field assay and on home cage running wheels. We are currently examining the relationship between physical activity and weight, as well as the role of the striatal dopaminergic system in mediating that relationship.

back to top