Co-expression of two subtypes of melatonin receptor on rat M1-type intrinsically photosensitive retinal ganglion cells

Wen-Long Sheng; Wei-Yi Chen; Xiong-Li Yang; Yong-Mei Zhong; Shi-Jun Weng

doi:10.1371/journal.pone.0117967

Co-expression of two subtypes of melatonin receptor on rat M1-type intrinsically photosensitive retinal ganglion cells

PLoS One. 2015 Feb 25;10(2):e0117967. doi: 10.1371/journal.pone.0117967. eCollection 2015.

Authors

Wen-Long Sheng¹, Wei-Yi Chen¹, Xiong-Li Yang¹, Yong-Mei Zhong¹, Shi-Jun Weng¹

Affiliation

¹ Institute of Neurobiology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China.

Abstract

Intrinsically photosensitive retinal ganglion cells (ipRGCs) are involved in circadian and other non-image forming visual responses. An open question is whether the activity of these neurons may also be under the regulation mediated by the neurohormone melatonin. In the present work, by double-staining immunohistochemical technique, we studied the expression of MT1 and MT2, two known subtypes of mammalian melatonin receptors, in rat ipRGCs. A single subset of retinal ganglion cells labeled by the specific antibody against melanopsin exhibited the morphology typical of M1-type ipRGCs. Immunoreactivity for both MT1 and MT2 receptors was clearly seen in the cytoplasm of all labeled ipRGCs, indicating that these two receptors were co-expressed in each of these neurons. Furthermore, labeling for both the receptors were found in neonatal M1 cells as early as the day of birth. It is therefore highly plausible that retinal melatonin may directly modulate the activity of ipRGCs, thus regulating non-image forming visual functions.

Publication types

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

MeSH terms

Animals
Animals, Newborn
Cytoplasm / metabolism
Gene Expression
Immunohistochemistry
Male
Photoreceptor Cells, Vertebrate / cytology
Photoreceptor Cells, Vertebrate / metabolism*
Protein Transport
Rats
Receptor, Melatonin, MT1 / genetics
Receptor, Melatonin, MT1 / metabolism*
Receptor, Melatonin, MT2 / genetics
Receptor, Melatonin, MT2 / metabolism*
Retinal Ganglion Cells / cytology
Retinal Ganglion Cells / metabolism*

Substances

Receptor, Melatonin, MT1
Receptor, Melatonin, MT2

Associated data

Dryad/10.5061/dryad.3Q7P2

Grants and funding

This work was supported by grants from the National Program of Basic Research sponsored by the Ministry of Science and Technology of China (2011CB504602; http://www.most.gov.cn/eng/), the National Natural Science Foundation of China (30930034, 31070967, 31171055, 31121061, 31100796; http://www.nsfc.gov.cn/Portal0/default152.htm), and an ARVO/Pfizer Collaborative Research Fellowship to Shi-Jun Weng (from the ARVO Foundation for Eye Research; http://www.arvo.org/foundation/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.