title: The ERG responses to light stimuli of melanopsin-expressing retinal ganglion cells that are independent of rods and cones.
abstract: The mechanisms by which melanopsin-expressing retinal ganglion cells (mRGCs) regulate circadian rhythms in humans have not been established. To understand mRGC characteristics and their role independent of effects due to the rods and cones, mRGC responses should be induced or measured independent of cone and rod responses. In the present study, we obtained results from light stimuli which differentially induce only the mRGC response by using a receptor-silent substitution technique. The mRGCs responded linearly to contrast changes of light stimuli, whereas they showed complicated responses to frequency changes with regard to the latency of response time. These results suggest that mRGC behavior is not a simple response to the various frequencies found in solar light but may be related to intrinsic neural circuits with feedback connections in the mRGC pathway. The results in this study also demonstrated that the test stimuli affected only the mRGC response and that this could be successfully detected by using the electroretinogram (ERG).
authors.affiliation: Department of Living Environmental Science, Fukuoka Women's University, Fukuoka, Japan. fukuda@fwu.ac.jp
authors.forename: Yumi
authors.initials: Y
authors.lastname: Fukuda
authors.forename: Sei-ichi
authors.initials: S
authors.lastname: Tsujimura
authors.forename: Shigekazu
authors.initials: S
authors.lastname: Higuchi
authors.forename: Akira
authors.initials: A
authors.lastname: Yasukouchi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Morita
mesh_terms: D000328:Adult; D002940:Circadian Rhythm; D004596:Electroretinography; D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology*; D012165:Retinal Ganglion Cells / Q000378:metabolism*; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology*; D017299:Rod Opsins / Q000096:biosynthesis*; D055815:Young Adult; D000099210:Melanopsin
chemical_list: D017299:Rod Opsins; D000099210:Melanopsin