The paraventricular thalamus input to central amygdala controls depression-related behaviors

The dysregulation of neuronal networks may contribute to the etiology of major depressive disorder (MDD). However, the neural connections underlying the symptoms of MDD have yet to be elucidated. Here, we observed that glutamatergic neurons in the paraventricular thalamus (PVT) were activated by chronic unpredictable stress (CUS) with higher expression numbers of ΔFosB-labeled neurons and protein expression levels, activation of PVT neurons caused depressive-like phenotypes, whereas suppression of PVT neuronal activity induced an antidepressant effect in male, but not female mice, which were achieved by using a chemogenetic approach. Moreover, we found that PVT glutamatergic neurons showed strong neuronal projections to the central amygdala (CeA), activation of the CeA-projecting neurons in PVT or the neuronal terminals of PVT-CeA projection neurons induced depression-related behaviors or showed enhanced stress-induced susceptibility. These results suggest that PVT is a key depression-controlling nucleus, and PVT-CeA projection regulates depression-related behaviors in a sex-dependent manner, which could be served as an essential pathway for morbidity and treatment of depression.