PMID- 29041976 OWN - NLM STAT- MEDLINE DCOM- 20171106 LR - 20181113 IS - 1880-6805 (Electronic) IS - 1880-6791 (Print) IS - 1880-6791 (Linking) VI - 36 IP - 1 DP - 2017 Oct 17 TI - Human pupillary light reflex during successive irradiation with 1-ms blue- and green-pulsed light. PG - 37 LID - 10.1186/s40101-017-0153-7 [doi] LID - 37 AB - BACKGROUND: In the human retina, the contribution of intrinsically photosensitive retinal ganglion cells (ipRGCs) to the regulation of the pupillary response remains poorly understood. The objective of the current study was to determine the response dynamics of the pupillary light reflex to short, successive pulses of light. In order to better assess the roles of ipRGCs and cones, we used pulses of blue and green light. METHODS: Each participant was exposed to 1-ms blue (466 nm) and/or green (527 nm) light pulses simultaneously or separately, with inter-stimulus intervals (ISIs) of 0, 250, 500, 750, or 1000 ms. Pupil diameter was measured using an infrared camera system. RESULTS: We found that human pupillary light responses during simultaneous irradiation or successive irradiation with ISIs /= 500 ms induced markedly increased pupillary constriction. CONCLUSIONS: We propose that this result may be related to cell hyperpolarization that occurs in the retina just after the first light stimulus is turned off, with the threshold for this effect being between 250 and 500 ms in the human retina. FAU - Lee, Soomin AU - Lee S AUID- ORCID: 0000-0002-7737-1163 AD - Center for Environment, Health and Field Sciences, Chiba University, 6-2-1, Kashiwanoha, Kashiwa, 277-0882, Japan. yisoomin@chiba-u.jp. FAU - Muto, Naoko AU - Muto N AD - Faculty of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan. FAU - Shimomura, Yoshihiro AU - Shimomura Y AD - Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan. FAU - Katsuura, Tetsuo AU - Katsuura T AD - Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan. LA - eng PT - Journal Article DEP - 20171017 PL - England TA - J Physiol Anthropol JT - Journal of physiological anthropology JID - 101269653 SB - IM MH - Adult MH - Anthropology, Physical MH - Female MH - Humans MH - Light MH - Photic Stimulation/*methods MH - Reflex, Pupillary/*physiology MH - Retinal Ganglion Cells/*physiology MH - Young Adult PMC - PMC5646119 COIS- ETHICS APPROVAL AND CONSENT TO PARTICIPATE: Our experiment received institutional ethics approval from the Ethics Committee of the Graduate School of Engineering at Chiba University (no. 26-23), and written informed consent was obtained from each participant. CONSENT FOR PUBLICATION: All participants gave written informed consent for publication after a complete explanation of this study. COMPETING INTERESTS: The authors declare that they have no competing interests. PUBLISHER'S NOTE: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. EDAT- 2017/10/19 06:00 MHDA- 2017/11/07 06:00 PMCR- 2017/10/17 CRDT- 2017/10/19 06:00 PHST- 2017/08/01 00:00 [received] PHST- 2017/10/10 00:00 [accepted] PHST- 2017/10/19 06:00 [entrez] PHST- 2017/10/19 06:00 [pubmed] PHST- 2017/11/07 06:00 [medline] PHST- 2017/10/17 00:00 [pmc-release] AID - 10.1186/s40101-017-0153-7 [pii] AID - 153 [pii] AID - 10.1186/s40101-017-0153-7 [doi] PST - epublish SO - J Physiol Anthropol. 2017 Oct 17;36(1):37. doi: 10.1186/s40101-017-0153-7.