title: Dorsal raphe nucleus projecting retinal ganglion cells: Why Y cells?
abstract: Retinal ganglion Y (alpha) cells are found in retinas ranging from frogs to mice to primates. The highly conserved nature of the large, fast conducting retinal Y cell is a testament to its fundamental task, although precisely what this task is remained ill-defined. The recent discovery that Y-alpha retinal ganglion cells send axon collaterals to the serotonergic dorsal raphe nucleus (DRN) in addition to the lateral geniculate nucleus (LGN), medial interlaminar nucleus (MIN), pretectum and the superior colliculus (SC) has offered new insights into the important survival tasks performed by these cells with highly branched axons. We propose that in addition to its role in visual perception, the Y-alpha retinal ganglion cell provides concurrent signals via axon collaterals to the DRN, the major source of serotonergic afferents to the forebrain, to dramatically inhibit 5-HT activity during orientation or alerting/escape responses, which dis-facilitates ongoing tonic motor activity while dis-inhibiting sensory information processing throughout the visual system. The new data provide a fresh view of these evolutionarily old retinal ganglion cells.
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska, Lincoln, NE, 68583, United States; Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE, 68198, United States; GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China.
authors.forename: Gary E
authors.initials: GE
authors.lastname: Pickard
authors.affiliation: Department of Biomedical Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China; Department of Ophthalmology, The University of Hong Kong, Hong Kong, China; GHM Institute of CNS Regeneration, Jinan University, Guangzhou, China; State Key Laboratory for Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China. Electronic address: hrmaskf@hku.hk.
authors.forename: Kwok-Fai
authors.initials: KF
authors.lastname: So
authors.affiliation: Department of Anatomy and Embryology, School of Basic Medical Sciences, Peking University, Beijing, China; Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing, China; Key Laboratory for Visual Impairment and Restoration (Ministry of Education), Peking University, Beijing, China. Electronic address: mpu@bjmu.edu.cn.
authors.forename: Mingliang
authors.initials: M
authors.lastname: Pu
mesh_terms: D000818:Animals; D065847:Dorsal Raphe Nucleus / Q000502:physiology*; D006801:Humans; D009043:Motor Activity / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000502:physiology*; D012701:Serotonin / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*
chemical_list: D012701:Serotonin
keywords: Alpha cells; Dorsal raphe nucleus; Retinal ganglion cells; Y cells