Role of the circadian nuclear receptor REV-ERBα in dorsal raphe serotonin synthesis in mood regulation

Abstract

Affective disorders are frequently associated with disrupted circadian rhythms. The existence of rhythmic secretion of central serotonin (5-hydroxytryptamine, 5-HT) pattern has been reported; however, the functional mechanism underlying the circadian control of 5-HTergic mood regulation remains largely unknown. Here, we investigate the role of the circadian nuclear receptor REV-ERB alpha in regulating tryptophan hydroxylase 2 (Tph2), the rate-limiting enzyme of 5-HT synthesis. We demonstrate that the REV-ERB alpha expressed in dorsal raphe (DR) 5-HTergic neurons functionally competes with PET-1-a nuclear activator crucial for 5-HTergic neuron development. In mice, genetic ablation of DR 5-HTergic REV-ERB alpha increases Tph2 expression, leading to elevated DR 5-HT levels and reduced depression-like behaviors at dusk. Further, pharmacological manipulation of the mice DR REV-ERB alpha activity increases DR 5-HT levels and affects despair-related behaviors. Our findings provide valuable insights into the molecular and cellular link between the circadian rhythm and the mood-controlling DR 5-HTergic systems.,Circadian nuclear receptor, REV-ERBa regulates the rhythmic serotonin synthesis in the central nervous system, highlighting the molecular connections between circadian clock and mood regulation,