The rat retina has five types of ganglion-cell photoreceptors

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..

Medienart:

Artikel

Erscheinungsjahr:

2015

Erschienen:

2015

Enthalten in:

Zur Gesamtaufnahme - volume:130

Enthalten in:

Experimental eye research - 130(2015), Seite 17-28

Sprache:

Englisch

Beteiligte Personen:

Reifler, Aaron N [VerfasserIn]
Chervenak, Andrew P [Sonstige Person]
Dolikian, Michael E [Sonstige Person]
Benenati, Brian A [Sonstige Person]
Meyers, Benjamin S [Sonstige Person]
Demertzis, Zachary D [Sonstige Person]
Lynch, Andrew M [Sonstige Person]
Li, Benjamin Y [Sonstige Person]
Wachter, Rebecca D [Sonstige Person]
Abufarha, Fady S [Sonstige Person]
Dulka, Eden A [Sonstige Person]
Pack, Weston [Sonstige Person]
Zhao, Xiwu [Sonstige Person]
Wong, Kwoon Y [Sonstige Person]

Links:

Volltext
www.ncbi.nlm.nih.gov

BKL:

44.95

Themen:

Axons - physiology
Circadian Rhythm - physiology
Membrane Potentials - physiology
Reflex, Pupillary - physiology
Retinal Ganglion Cells - cytology
Retinal Ganglion Cells - physiology
Retinal Ganglion Cells - radiation effects
Rod Opsins - metabolism
Vision, Ocular - physiology

RVK:

RVK Klassifikation

doi:

10.1016/j.exer.2014.11.010

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

OLC1965407773