Osmoregulatory neurons clockwork is altered during metabolic disorder induced by high energy diet in the Sand rat Psammomys obesus

ABSTRACT Increasing evidences highlight the role of vasopressin (AVP) in the regulation of metabolic functions and the association between hydration state and metabolic disorders. Supraoptic nuclei (SON) neurons are particularly sensitive to metabolic changes, as shown by the loss of plasma AVP rhythmicity during diabetes. We aimed in this work to determine the effect of high energy (HE) feeding on SON clock functioning in Psammomys obesus, a desert herbivore rodent in which metabolic syndrome is nutritionally induced. Animals were subjected to either normal or HE feeding for 3 months. Immunohistochemical study indicates that AVP and the circadian transcription factor CLOCK profiles follow daily oscillations with higher content in the beginning of the rest period in control group fed with low energy (LE) diet. Our data show that HE feeding induces critical changes through impairment of daily AVP and CLOCK cycling in the SON. These findings show clearly that SON clockwork is altered by HE diet-induced metabolic changes. Further studies are needed to better understand SON neurons responses to metabolic derangement.