Meeting Abstract

111.2  Saturday, Jan. 7  Neurobiological correlates of voluntary exercise: Effects of selective breeding and a high-fat diet CLAGHORN, G.C.*; MEEK, T.H.; PEREA-RODRIGUEZ, J.P.; GARLAND JR, T.; University of California, Riverside; University of California, Riverside; University of California, Riverside; University of California, Riverside gclag001@ucr.edu

Patterns of brain activity during voluntary exercise differ between mice from lines that have been selectively bred for high voluntary wheel running (HR lines) and those from non-selected control (C) lines in regions associated with motivation, reward, learning, and energy balance (Rhodes et al. 2003, Behav. Neurosci. 117:1243-1256). In addition, a diet high in fat with added sucrose (Teklad Western Diet [WD]) was previously shown to stimulate wheel running in HR mice, with little or no effect on C mice (Meek et al., 2010, Int. J. Obesity 34:960-969). We hypothesize that basic neurobiological differences underlie the disparate response to WD between HR and C lines. More generally, highly palatable diets have been shown to change the reward response to unrelated stimuli, and the underlying physiology of these changes may shed light on addiction, compulsive overeating, attention deficit hyperactivity disorder or other human afflictions. Shortly following weaning at 21 days of age, HR and C mice were given ad lib access to either WD or standard chow and access to a wheel for ~6 weeks, at which point wheel running had reached an apparent plateau. Brains were harvested during peak wheel running, 2-3 hours after the onset of darkness. Patterns of brain activity will be examined in areas implicated in motivation, energy balance, and learning using cFos immunohistochemisty. Activity in regions of the dopaminergic signaling pathways will be examined with cFos and the colocalization of cFos and tyrosine hydroxylase. We hypothesize statistical interactions between line-type (HR vs. C), diet, and amount of wheel running prior to sampling. Supported by NSF Predoctoral Fellowship to GC and NSF grant IOS-1121273 to TG.