Abstract
Some Mexican volcano mice (Neotomodon alstoni), when in captivity and fed regularly on a laboratory rodents’ diet, develop obesity. The aims of the present work are to compare lean and obese mice with regard to the main characteristics of the sleep–wake cycle in 12:12 LD, and to investigate if there is a correlation with changes in metabolic-related blood parameters (leptin, insulin, triacylglycerides, corticosterone and the glucose tolerance test). The analysis of the sleep–wake cycle evaluated the temporal distribution of vigilance states and indicated a poly-phasic architecture. Trends were observed in obese mice to have increased percentages of slow wave sleep and decreased wakefulness, but the percentage of rapid eye movement sleep was not different. Obese mice had higher concentrations of leptin and insulin, and showed a slower glucose removal from blood at noon than at midnight, indicating a possible resistance to these hormones. We propose that volcano mice are a good model for studying daily rhythms and metabolic disorders related to obesity.
Acknowledgments
We would like to thank Jim Waterhouse for English edition and useful comments; M. Soriano, D. Salazar and I. Antunez for animal care and animal house assistance. This work was supported by PAPIIT, UNAM IN225311; CFG was supported by CONACyT scholar fellowship in Posgrado en Ciencias Biológicas No 220274-23056 for M.Sc. degree.