Author: Manuel Tomás Crespo | Email: email@example.com
Manuel Crespo 1°, Emilia Zapiola 1°, Julieta Acosta 1°, Diego Golombek 1°, Juan Chiesa 1°, Patricia Agostino 1°
1° Laboratorio de Cronobiología, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes
The circadian system regulates several physiological, metabolic, and behavioural rhythms with a period close to 24 h. The molecular basis of this clock consists of a series of negative feedback mechanisms between specific genetic components, such as Per, Cry, Clock and Bmal1 genes. When the availability of food is restricted to an interval of the day (time restricted feeding, TRF), the animals adapt to this condition by feeding only during this interval and develop a food anticipatory activity (FAA) driven by a food-entrainable oscillator (FEO). One of the peripheral circadian oscillators is the gut microbiota, which regulates the synthesis and release of neuromodulators through the microbiota-gut-brain axis.
In this work, we present evidence that motivation for food reward – assayed through the progressive ratio schedule is affected by microbiota depletion and the loss of the circadian gene Per2. In this sense, our results indicate that microbiota depletion with antibiotic treatment affected FAA and motivation under a TRF protocol, demonstrating a role for the gut microbiota in regulating brain reward functions. Moreover, motivation was significantly diminished in the Per2-/- mice, confirming a role of Per2 in motivation processes.
Together, these findings contribute to gain knowledge in potential mechanisms of circadian modulation of motivational states in order to improve treatment related to psychiatric disorders or drugs of abuse and mental disorders.