Chaoran Ren 1 , 2 , 3 , Liju Luan 1 , 2 , 3 , Benson Wui-Man Lau 4 , 5 , 6 , Xin Huang 1 , 2 , 3 , Jian Yang 4 , 5 , 6 , Yuan Zhou 1 , 2 , 3 , Xihong Wu 3 , 7 , Jie Gao 1 , 2 , 3 , Gary E Pickard 8 , 9 , Kwok-Fai So 4 , 5 , 6 , * , Mingliang Pu 1 , 2 , 3 , *
27 February 2013
Affective visual information, Animal models, Depression, Dorsal Raphe Nucleus, Fluoxetine, Mood, Anxiety, Stress Disorders, Neurophysiology, Retinal ganglion cells, Serotonin, dorsal raphe nucleus, retinal ganglion cell, depression, affective visual information, SSRI
Light is a powerful modulator of higher-order cognitive processes such as mood but it remains unclear which neural circuits mediate the impact of light on affective behavior. We found that light deprivation produces a depressive-like behavioral state that is reversed by activation of direct retinal signals to the serotonergic dorsal raphe nucleus (DRN) in a manner equivalent to treatment with the selective serotonin reuptake inhibitor fluoxetine. Surprisingly, the DRN-projecting retinal ganglion cells (RGCs) are indistinguishable from the classic alpha/Y-like RGC type that contributes to image-forming visual pathways. Silencing RGC firing or specific immunotoxin ablation of DRN-projecting RGCs increased depressive-like behavior and reduced serotonin levels in the DRN. Serotonin has a key role in the pathophysiology of depression, and these results demonstrate that retino-raphe signals modulate DRN serotonergic tone and affective behavior.