title: Dendritic morphology of caudal periaqueductal gray projecting retinal ganglion cells in Mongolian gerbil (Meriones unguiculatus).
abstract: In this study we investigated the morphological features of the caudal periaqueductal gray (cPAG)-projecting retinal ganglion cells (RGCs) in Mongolian gerbils using retrograde labeling, in vitro intracellular injection, confocal microscopy and three-dimensional reconstruction approaches. cPAG-projecting RGCs exhibit small somata (10-17 µm) and irregular dendritic fields (201-298 µm). Sizes of somata and dendritic fields do not show obvious variation at different distance from the optic disk (eccentricity). Dendrites are moderately branched. Morphological analysis (n = 23) reveals that cPAG-projecting RGCs ramified in sublamina a and b in the inner plexiform layer. These cells exhibit different stratification patterns based on the thickness of dendritic bands in sublaminas a and b: majority of analyzed cells (16 out of 23) have two bands of arborizations share similar thickness. The rest of analyzed cells (7 out of 23) exhibit thinner band in sublamina a than in sublamina b. Together, the present study suggests that cPAG of Mongolian gerbil could receive direct retinal inputs from two types of bistratified RGCs. Furthermore, a small subset of melanopsin-expressing RGCs (total 41 in 6 animals) is shown to innervate the rostral PAG (rPAG). Functional characteristics of these non-visual center projecting RGCs remain to be determined.
authors: Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, PR China; Guangdong Medical Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, PR China; GHM Collaboration and Innovation Center for Tissue Regeneration and Repair, Jinan University, Guangzhou, PR China.
authors: Chaoran
authors: C
authors: Ren
authors: Department of Anatomy, School of Basic Medical Sciences, Peking University, Beijing, PR China; Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing, PR China; Key Laboratory for Visual Impairment and Restoration (Ministry of Education), Peking University, Beijing, PR China.
authors: Mingliang
authors: M
authors: Pu
authors: Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, PR China; Guangdong Medical Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, PR China; GHM Collaboration and Innovation Center for Tissue Regeneration and Repair, Jinan University, Guangzhou, PR China.
authors: Qi
authors: Q
authors: Cui
authors: Guangdong-Hongkong-Macau Institute of CNS Regeneration, Jinan University, Guangzhou, PR China; Guangdong Medical Key Laboratory of Brain Function and Diseases, Jinan University, Guangzhou, PR China; GHM Collaboration and Innovation Center for Tissue Regeneration and Repair, Jinan University, Guangzhou, PR China; Department of Ophthalmology and State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, PR China.
authors: Kwok-Fai
authors: KF
authors: So
mesh_terms: D000818:Animals; D003712:Dendrites / Q000648:ultrastructure*; D005849:Gerbillinae / Q000033:anatomy & histology*; D008297:Male; D010487:Periaqueductal Gray / Q000166:cytology* / Q000648:ultrastructure; D012160:Retina / Q000166:cytology; D012165:Retinal Ganglion Cells / Q000648:ultrastructure*; D017299:Rod Opsins / Q000032:analysis; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin