Chronobiology
Author: Julieta Acosta | Email: juli.acosta05@gmail.com
Julieta Acosta 1°, Victoria A. Acosta-Rodríguez 2°, Nathan Skinner 2°, Justin Krupp 2°, Diego A. Golombek 3°, Joseph S. Takahashi 2°, Patricia V. Agostino 1°
1° Laboratorio de Cronobiología, Universidad Nacional de Quilmes/CONICET, Buenos Aires, Argentina.
2° Department of Neuroscience, Peter O’Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, USA.
3° Laboratorio Interdisciplinario del Tiempo y la Experiencia (LITERA), CONICET, Universidad de San Andrés, Buenos Aires, Argentina.
Most living organisms possess a circadian timing system that has evolved to finely tune their daily interaction with the environment. In mammals, the main circadian clock is synchronized by the light-dark (LD) cycle. Nutrition also strongly influences circadian rhythms. Specifically, when food intake is limited to a few hours each day, it can become a strong synchronizer that triggers food anticipatory rhythms.
We have shown that motivation for food reward is regulated in a circadian manner in mice, peaking at night. This study aims to characterize how the rhythm in motivation is affected by misaligned food and light schedules. We exposed male and female C57Bl/6j mice to 4-hour time-restricted feeding during the light (TRF-D) or dark (TRF-N) phase of the LD cycle. Then, motivation was assessed using the Progressive Ratio task at three different time points. Nucleus Accumbens tissue was collected for mRNA analysis through bulk RNA-seq and single nuclei RNA-seq approaches.
In female and male TRF-N groups, where light and food schedules are aligned, the motivational state increased with fasting hours. Misaligned schedules triggered sex-specific responses. Male TRF-D mice exhibited a greater self-imposed caloric restriction, leading to increased motivational levels at all time points. Females displayed a unique double peak motivational response. These findings advance understanding of circadian impact on motivation, aiming to aid psychiatric and substance abuse treatment.