Dendritic morphology of caudal periaqueductal gray projecting retinal ganglion cells in Mongolian gerbil (Meriones unguiculatus)

Chaoran Ren; Mingliang Pu; Qi Cui; Kwok-Fai So

doi:10.1371/journal.pone.0103306

Dendritic morphology of caudal periaqueductal gray projecting retinal ganglion cells in Mongolian gerbil (Meriones unguiculatus)

PLoS One. 2014 Jul 23;9(7):e103306. doi: 10.1371/journal.pone.0103306. eCollection 2014.

Authors

Chaoran Ren¹, Mingliang Pu², Qi Cui¹, Kwok-Fai So³

Affiliations

¹ 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.
² 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.
³ 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.

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.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Dendrites / ultrastructure*
Gerbillinae / anatomy & histology*
Male
Periaqueductal Gray / cytology*
Periaqueductal Gray / ultrastructure
Retina / cytology
Retinal Ganglion Cells / ultrastructure*
Rod Opsins / analysis

Substances

Rod Opsins
melanopsin

Grants and funding

This work was funded by The National Program on Key Basic Research Project of China (KFS, 973 Program: 2011CB707501 and 2014CB542205); The Fundamental Research Funds for the Central Universities Grant (KFS, 21609101); Guangdong Natural Science Foundation (CRR, S2013040014831) and the Programme of Introducing Talents of Discipline to Universities (B14036). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.