Low-frequency LFP oscillations (1-9 Hz) changes reward-related brain regions during sugar-based T-maze decision...

The global rise in sugar-rich diets is a major public health concern because excessive sugar intake can disrupt the brain's reward circuitry. This neurobiological dysfunction is considered a key factor leading to significant health complications, including obesity, sugar addiction, and neurological issues, which requires a deeper understanding of sugar's effects on the brain and behavior. This study investigated the impact of chronic consumption of sugar-enriched agar-based diet (SD) compared to a control diet (CD) in male C57BL/6Mlac mice. A T-maze task was used to assess reward-seeking behavior, while local field potential (LFP) recordings were obtained from neural circuit related with reward processing including the nucleus accumbens (NAc), dorsal hippocampus (dHP), medial prefrontal cortex (mPFC), and olfactory bulb (OB) to evaluate neural dynamics. Mice in the SD-group exhibited a significant increase in body weight, indicating metabolic adaptation to chronic sugar intake. However, behavioral analysis revealed no significant differences between the SD- and CD-groups in terms of percent time preference or total traveled distance, suggesting that prolonged sugar consumption may not have overtly enhanced reward-seeking behavior in this paradigm. In contrast, neurophysiological data showed a significant reduction in the NAc theta-band (5-9 Hz) LFP power during the turning epoch. This dissociation between behavioral outcomes and neural activity points to the complexity of sugar's effects on the brain, possibly involving compensatory mechanisms in other regions of the reward circuitry. These findings highlight the sensitivity of the NAc to chronic sugar exposure and provide novel insights into the neural substrates underlying sugar-related decision-making.