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Journal of Ophthalmology
Volume 2017, Article ID 6804853, 8 pages
https://doi.org/10.1155/2017/6804853
Research Article

Regulation of Reentrainment Function Is Dependent on a Certain Minimal Number of Intact Functional ipRGCs in rd Mice

1Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, China
2Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, China

Correspondence should be addressed to Ningli Wang; moc.361.piv@ilgninw

Received 8 June 2017; Accepted 10 October 2017; Published 22 November 2017

Academic Editor: Ji-jing Pang

Copyright © 2017 Jingxue Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose. To investigate the effect of partial ablation of melanopsin-containing retinal ganglion cells (mcRGCs) on nonimage-forming (NIF) visual functions in rd mice lacking rods. Methods. The rd mice were intravitreally injected with different doses (100 ng/μl, 200 ng/μl, and 400 ng/μl) of immunotoxin melanopsin-SAP. And then, the density of ipRGCs was examined. After establishing the animal models with different degrees of ipRGC damage, a wheel-running system was used to evaluate their reentrainment response. Results. Intravitreal injection of melanopsin-SAP led to partial ablation of ipRGCs in a dose-dependent manner. The survival rates of ipRGCs in the 100 ng/μl, 200 ng/μl, and 400 ng/μl groups were 74.14% ± 4.15%, 39.25% ± 2.29%, and 38.38% ± 3.74%, respectively. The wheel-running experiments showed that more severe ipRGC loss was associated with a longer time needed for reentrainment. When the light/dark cycle was delayed by 8 h, the rd mice in the PBS control group took 4.67 ± 0.79 days to complete the synchronization with the shifted cycle, while those in the 100 ng/μl and 200 ng/μl groups required 7.90 ± 0.55 days and 11.00 ± 0.79 days to complete the synchronization with the new light/dark cycle, respectively. Conclusion. Our study indicates that the regulation of some NIF visual functions is dependent on a certain minimal number of intact functional ipRGCs.