title: The melanopic sensitivity function accounts for melanopsin-driven responses in mice under diverse lighting conditions.
abstract: In addition to rods and cones, photoreception in mammals extends to a third retinal cell type expressing the photopigment melanopsin. The influences of this novel opsin are widespread, ranging from pupillary and circadian responses to brightness perception, yet established approaches to quantifying the biological effects of light do not adequately account for melanopsin sensitivity. We have recently proposed a novel metric, the melanopic sensitivity function (V(Z)λ), to address this deficiency. Here, we further validate this new measure with a variety of tests based on potential barriers to its applicability identified in the literature or relating to obvious practical benefits. Using electrophysiogical approaches and pupillometry, initially in rodless+coneless mice, our data demonstrate that under a very wide range of different conditions (including switching between stimuli with highly divergent spectral content) the V(Z)λ function provides an accurate prediction of the sensitivity of melanopsin-dependent responses. We further show that V(Z)λ provides the best available description of the spectral sensitivity of at least one aspect of the visual response in mice with functional rods and cones: tonic firing activity in the lateral geniculate nuclei. Together, these data establish V(Z)λ as an important new approach for light measurement with widespread practical utility.
authors.affiliation: Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Brown
authors.forename: Annette E
authors.initials: AE
authors.lastname: Allen
authors.forename: Jazi
authors.initials: J
authors.lastname: al-Enezi
authors.forename: Jonathan
authors.initials: J
authors.lastname: Wynne
authors.forename: Luc
authors.initials: L
authors.lastname: Schlangen
authors.forename: Vanja
authors.initials: V
authors.lastname: Hommes
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lucas
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D004594:Electrophysiology; D008027:Light; D008297:Male; D051379:Mice; D008959:Models, Neurological; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism / Q000502:physiology*; D011680:Pupil / Q000502:physiology*; D012160:Retina / Q000502:physiology; D017299:Rod Opsins / Q000378:metabolism*; D014785:Vision, Ocular; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin