title: Multiple cone pathways are involved in photic regulation of retinal dopamine.
abstract: Dopamine is a key neurotransmitter in the retina and plays a central role in the light adaptive processes of the visual system. The sole source of retinal dopamine is dopaminergic amacrine cells (DACs). We and others have previously demonstrated that DACs are activated by rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) upon illumination. However, it is still not clear how each class of photosensitive cells generates light responses in DACs. We genetically isolated cone function in mice to specifically examine the cone-mediated responses of DACs and their neural pathways. In addition to the reported excitatory input to DACs from light-increment (ON) bipolar cells, we found that cones alternatively signal to DACs via a retrograde signalling pathway from ipRGCs. Cones also produce ON and light-decrement (OFF) inhibitory responses in DACs, which are mediated by other amacrine cells, likely driven by type 1 and type 2/3a OFF bipolar cells, respectively. Dye injections indicated that DACs had similar morphological profiles with or without ON/OFF inhibition. Our data demonstrate that cones utilize specific parallel excitatory and inhibitory circuits to modulate DAC activity and efficiently regulate dopamine release and the light-adaptive state of the retina.
authors.affiliation: Institutes of Brain Science, Fudan University, Shanghai 200032, China.|Eye Research Institute, Oakland University, Rochester, MI 48309, USA.
authors.forename: Sheng-Nan
authors.initials: SN
authors.lastname: Qiao
authors.affiliation: Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
authors.forename: Zhijing
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Ruiz Department of Ophthalmology and Visual Science, McGovern Medical School, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.|Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
authors.forename: Christophe P
authors.initials: CP
authors.lastname: Ribelayga
authors.affiliation: Institutes of Brain Science, Fudan University, Shanghai 200032, China.|State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.|Collaborative Innovation Center for Brain Science, Fudan University, Shanghai 200032, China.
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Zhong
authors.affiliation: Eye Research Institute, Oakland University, Rochester, MI 48309, USA.
authors.forename: Dao-Qi
authors.initials: DQ
authors.lastname: Zhang
mesh_terms: D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D025042:Amacrine Cells / Q000502:physiology / Q000528:radiation effects; D000818:Animals; D004298:Dopamine / Q000032:analysis; D007150:Immunohistochemistry; D008027:Light; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials / Q000528:radiation effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018408:Patch-Clamp Techniques; D012165:Retinal Ganglion Cells / Q000473:pathology / Q000502:physiology* / Q000528:radiation effects; D000097573:Red Fluorescent Protein
chemical_list: D015102:3,4-Dihydroxyphenylacetic Acid; D004298:Dopamine; D008164:Luminescent Proteins; D000097573:Red Fluorescent Protein