Neuronal activity in the anterior paraventricular nucleus of thalamus positively correlated with sweetener consumption in mice

Although the brain can discriminate between various sweet substances, the underlying neural mechanisms of this complex behavior remain elusive. This study examines the role of the anterior paraventricular nucleus of the thalamus (aPVT) in governing sweet preference in mice. We fed the mice six different diets with equal sweetness for six weeks: control diet (CD), high sucrose diet (HSD), high stevioside diet (HSSD), high xylitol diet (HXD), high glycyrrhizin diet (HGD), and high mogroside diet (HMD). The mice exhibited a marked preference specifically for the HSD and HSSD. Following consumption of these diets, c-Fos expression levels in the aPVT were significantly higher in these two groups compared to the others. Utilizing fiber photometry calcium imaging, we observed rapid activation of aPVT neurons in response to sucrose and stevioside intake, but not to xylitol or water. Our findings suggest that aPVT activity aligns with sweet preference in mice, and notably, stevioside is the sole plant-based sweetener that elicits an aPVT response comparable to that of sucrose.