Sweetness effect of stevioside in paraventricular thalamic enhanced the feeding motivation of mice

Abstract

Attitudes towards the consumption of various types of sweetened food products are controlled by the central nervous system. Therefore, finding the brain regions responsible for regulating the feeding decisions on sweeteners in animals will provide new strategies for the development of sweeteners. Here, we selected sucrose and the other two plant sweeteners: stevioside and xylitol, then provided the mice with the diets supplemented with 25% sucrose, 1.25% stevioside and 25.05% xylitol, respectively, to ensure that these diets had the same sweetness. The mice showed strong preference for HSD (high sucrose diet) and HSSD (high stevioside diet), but they were not interested in HXD (high xylitol diet) with the same sweetness as HSD. After six weeks of intermittent exposure to different sweet diets, when the mice have consumed the corresponding diet, the c-fos expression level in paraventricular thalamic (PVT) of mice in HSD group is significantly higher than those in the HXD group (p < 0.0001) and CD group (p = 0.0006), and there was no significant difference from the HSSD group to HXD group (p = 0.0507). Though fiber photometry, we found that the PVT of mice were involved in the feeding motivation of different sweet diets. When the mice consumed sucrose solution, the neuronal activity of PVT increased rapidly and peaked at the instant when the mice obtained the sucrose solution, this phenomenon was also observed in the HSSD group of mice. The PVT activity of mice exposed to water and xylitol solutions has no fluctuation. Our data indicate that PVT is involved in the regulation of the feeding motivation of mice for different sweeteners, and stevioside can activate PVT like sucrose to increase the feeding motivation of animals.