title: Effects of strobe light stimulation on postnatal developing rat retina.
abstract: The nature and intensity of visual stimuli have changed in recent years because of television and other dynamic light sources. Although light stimuli accompanied by contrast and strength changes are thought to have an influence on visual system development, little information is available on the effects of dynamic light stimuli such as a strobe light on visual system development. Thus, this study was designed to evaluate changes caused by dynamic light stimuli during retinal development. This study used 80 Sprague-Dawley rats. From eye opening (postnatal day 14), half of the rats were maintained on a daily 12-h light/dark cycle (control group) and the remaining animals were raised under a 12-h strobe light (2 Hz)/dark cycle (strobe light-reared group). Morphological analyses and electroretinogram (ERG) were performed at postnatal weeks 3, 4, 6, 8, and 10. Among retinal neurons, tyrosine hydroxylase-immunoreactive (TH-IR, dopaminergic amacrine cells) cells showed marked plastic changes, such as variations in numbers and soma sizes. In whole-mount preparations at 6, 8, and 10 weeks, type I TH-IR cells showed a decreased number and larger somata, while type II TH-IR cells showed an increased number in strobe-reared animals. Functional assessment by scotopic ERG showed that a-wave and b-wave amplitudes increased at 6 and 8 weeks in strobe-reared animals. These results show that exposure to a strobe light during development causes changes in TH-IR cell number and morphology, leading to a disturbance in normal visual functions.
authors.affiliation: Department of Anatomy, School of Medicine, Ewha Womans University, 911-1 Mok5dong, Yang-chon, Seoul, 158-710, Korea.
authors.forename: Jung-A
authors.initials: JA
authors.lastname: Shin
authors.forename: Eojin
authors.initials: E
authors.lastname: Jeong
authors.forename: In-Beom
authors.initials: IB
authors.lastname: Kim
authors.forename: Hwa-Young
authors.initials: HY
authors.lastname: Lee
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002452:Cell Count; D004596:Electroretinography; D005071:Evoked Potentials / Q000528:radiation effects; D008027:Light; D009474:Neurons / Q000378:metabolism / Q000528:radiation effects; D010775:Photic Stimulation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000166:cytology / Q000254:growth & development / Q000528:radiation effects; D012542:Scattering, Radiation; D018709:Statistics, Nonparametric; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014795:Visual Pathways / Q000187:drug effects* / Q000254:growth & development*
chemical_list: D014446:Tyrosine 3-Monooxygenase