Direct retino-raphe projection alters serotonergic tone and affective behavior.
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.
Department of Anatomy, School of Basic Medical Sciences, Peking University, Beijing, China.
Chaoran
C
Ren
Liju
L
Luan
Benson
B
Wui-Man Lau
Xin
X
Huang
Jian
J
Yang
Yuan
Y
Zhou
Xihong
X
Wu
Jie
J
Gao
Gary E
GE
Pickard
Kwok-Fai
KF
So
Mingliang
M
Pu
D000200:Action Potentials / Q000187:drug effects / Q000502:physiology; D000339:Affect / Q000187:drug effects / Q000502:physiology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D003624:Darkness; D005473:Fluoxetine / Q000494:pharmacology; D005849:Gerbillinae; D007099:Imipramine / Q000494:pharmacology; D008297:Male; D009434:Neural Pathways / Q000378:metabolism / Q000502:physiology; D011903:Raphe Nuclei / Q000378:metabolism / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*
D005473:Fluoxetine; D012701:Serotonin; D007099:Imipramine