RT info:eu-repo/semantics/article T1 Drastic decline in vasoactive intestinal peptide expression in the suprachiasmatic nucleus in obese mice on a long-term high-fat diet. A1 Afonso Oramas, Domingo A1 Santana Cordón, Laura A1 Lemus Mesa, Alejandro A1 Teixidó Trujillo, Silvia A1 Rodríguez Rodríguez, Ana Elena A1 Cruz Muros, Ignacio de la A1 González Gómez, Miriam A1 Barroso Chinea, Pedro K1 Suprachiasmatic nucleus K1 Nucleus accumbens K1 Vasoactive intestinal peptide K1 Neuropeptide y obesity K1 High-fat diet AB The suprachiasmatic nucleus (SCN) is the main region for the regulation of circadian rhythms. Although the SCN contains a heterogeneous neurochemical phenotype with a wide variety of neuropeptides, a key role has been suggested for the vasoactive intestinal neuropeptide (VIP) as a modulator circadian, reproductive, and seasonal rhythms. VIP is a 28-amino acid polypeptide hormone that belongs to the secretin-glucagon peptide superfamily and shares 68 % homology with the pituitary adenylate cyclase-activating polypeptide (PACAP). VIP acts as an endogenous appetite inhibitor in the central nervous system, where it participates in the control of appetite and energy homeostasis. In recent years, significant efforts have been made to better understand the role of VIP in the regulation of appetite/satiety and energy balance. This study aimed to elucidate the long-term effect of an obesogenic diet on the distribution and expression pattern of VIP in the SCN and nucleus accumbens (NAc) of C57BL/6 mice. A total of 15 female C57BL/6J mice were used in this study. Female mice were fed ad libitum with water and, either a standard diet (SD) or a high-fat diet (HFD) to induce obesity. There were 7 female mice on the SD and 8 on the HFD. The duration of the experiment was 365 days. The morphological study was performed using immunohistochemistry and double immunofluorescence techniques to study the neurochemical profile of VIP neurons of the SCN of C57BL/6 mice. Our data show that HFD-fed mice gained weight and showed reduced VIP expression in neurons of the SCN and also in fibres located in the NAc. Moreover, we observed a loss of neuropeptide Y (NPY) expression in fibres surrounding the SCN. Our findings on VIP may contribute to the understanding of the pathophysiological mechanisms underlying obesity in regions associated with uncontrolled intake of high-fat foods and the reward system, thus facilitating the identification of novel therapeutic targets. SN 1873-2747 YR 2023 FD 2023 LK http://riull.ull.es/xmlui/handle/915/35026 UL http://riull.ull.es/xmlui/handle/915/35026 LA en DS Repositorio institucional de la Universidad de La Laguna RD 08-oct-2024