The rat retina has five types of ganglion-cell photoreceptors.

Autor: Reifler AN; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Chervenak AP; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Dolikian ME; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Benenati BA; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Meyers BS; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Demertzis ZD; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Lynch AM; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Li BY; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Wachter RD; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Abufarha FS; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Dulka EA; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Pack W; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Zhao X; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA., Wong KY; Department of Ophthalmology & Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA; Department of Molecular, Cellular & Developmental Biology, University of Michigan, Ann Arbor, MI 48105, USA. Electronic address: kwoon@umich.edu.
Jazyk: angličtina
Zdroj: Experimental eye research [Exp Eye Res] 2015 Jan; Vol. 130, pp. 17-28. Date of Electronic Publication: 2014 Nov 18.
DOI: 10.1016/j.exer.2014.11.010
Abstrakt: Intrinsically photosensitive retinal ganglion cells (ipRGCs) are inner retinal photoreceptors that mediate non-image-forming visual functions, e.g. pupillary constriction, regulation of pineal melatonin release, and circadian photoentrainment. Five types of ipRGCs were recently discovered in mouse, but whether they exist in other mammals remained unknown. We report that the rat also has five types of ipRGCs, whose morphologies match those of mouse ipRGCs; this is the first demonstration of all five cell types in a non-mouse species. Through immunostaining and λmax measurements, we showed that melanopsin is likely the photopigment of all rat ipRGCs. The various cell types exhibited diverse spontaneous spike rates, with the M1 type spiking the least and M4 spiking the most, just like we had observed for their mouse counterparts. Also similar to mouse, all ipRGCs in rat generated not only sluggish intrinsic photoresponses but also fast, synaptically driven ones. However, we noticed two significant differences between these species. First, whereas we learned previously that all mouse ipRGCs had equally sustained synaptic light responses, rat M1 cells' synaptic photoresponses were far more transient than those of M2-M5. Since M1 cells provide all input to the circadian clock, this rat-versus-mouse discrepancy could explain the difference in photoentrainment threshold between mouse and other species. Second, rat ipRGCs' melanopsin-based spiking photoresponses could be classified into three varieties, but only two were discerned for mouse ipRGCs. This correlation of spiking photoresponses with cell types will help researchers classify ipRGCs in multielectrode-array (MEA) spike recordings.
(Copyright © 2014 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
Externí odkaz: