CHARACTERIZING ELECTROPHYSIOLOGICAL DATA RECORDED DURING BINGE EATING BEHAVIOR IN RATS

Binge eating (BE) is a difficult-to-treat behavior with high relapse rates, thus complicating several disorders including obesity. Studies trying to better understand eating disorders including BE behavior using systems neuroscience approaches have used EEG, functional MRI, and PET in patients with and without BE. Few studies, however, have attempted to use systems neuroscience approaches in pre-clinical models of BE. This approach holds the promise of being used to characterize the activity of brain circuits underlying BE behavior to find similarities with clinical data and help validate existing pre-clinical models. To address this knowledge gap, we recorded brain reward circuit activity during BE sessions with and without induction of various amounts of hunger. We correlated recorded brain reward circuit activity changes with observed increases in binge size that were induced by food deprivation (24 and 48 hours). Rats (N=12) were placed in a chamber with food and local field potential (LFP) was recorded for 90 minutes. LFP was recorded in each rat using electrodes implanted in the bilateral nucleus accumbens (NAc) core and shell. The two main behaviors that were defined from the recorded video were a rest behavior and a binge behavior. A rest was defined as little to no movement and a binge was defined as the time interval during which food was consumed. The electrophysiological data was processed and LFP data associated with rest was compared to that associated with binge within animals. Overall during a binge session, the comparison of rest LFP power spectral densities from 4-90 Hz revealed that the power in the theta, alpha, and beta bands showed a decrease from rest to binge behavior across animals. Low and high gamma frequency ranges showed a slight but statistically significant increase from the resting state to active binge state, indicating that a correlation exists between the observed behavior and the neural data. Ongoing analysis seeks to identify LFP features (power, phase coherence, and power coupling) that correlate with binge size variation induced by food deprivation (24hrs or 48hrs). We have begun to define a neural signature of how BE is distinct from rest. In future, we hope to identify specific features that correlate with hunger and the palatability of the food through ongoing analysis.