title: Circadian perinatal photoperiod has enduring effects on retinal dopamine and visual function.
abstract: Visual system development depends on neural activity, driven by intrinsic and light-sensitive mechanisms. Here, we examined the effects on retinal function due to exposure to summer- and winter-like circadian light cycles during development and adulthood. Retinal light responses, visual behaviors, dopamine content, retinal morphology, and gene expression were assessed in mice reared in seasonal photoperiods consisting of light/dark cycles of 8:16, 16:8, and 12:12 h, respectively. Mice exposed to short, winter-like, light cycles showed enduring deficits in photopic retinal light responses and visual contrast sensitivity, but only transient changes were observed for scotopic measures. Dopamine levels were significantly lower in short photoperiod mice, and dopaminergic agonist treatment rescued the photopic light response deficits. Tyrosine hydroxylase and Early Growth Response factor-1 mRNA expression were reduced in short photoperiod retinas. Therefore, seasonal light cycles experienced during retinal development and maturation have lasting influence on retinal and visual function, likely through developmental programming of retinal dopamine.
authors.affiliation: Department of Biological Sciences, Vanderbilt University, Nashville, Tennessee 37235 and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37235.
authors.forename: Chad R
authors.initials: CR
authors.lastname: Jackson
authors.forename: Megan
authors.initials: M
authors.lastname: Capozzi
authors.forename: Heng
authors.initials: H
authors.lastname: Dai
authors.forename: Douglas G
authors.initials: DG
authors.lastname: McMahon
mesh_terms: D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001549:Benzamides / Q000494:pharmacology; D002940:Circadian Rhythm / Q000502:physiology*; D015350:Contrast Sensitivity / Q000187:drug effects; D004298:Dopamine / Q000378:metabolism*; D018491:Dopamine Agonists / Q000494:pharmacology; D004622:Embryo, Mammalian; D005260:Female; D015870:Gene Expression / Q000187:drug effects / Q000528:radiation effects; D008027:Light; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017120:Nystagmus, Optokinetic / Q000187:drug effects / Q000502:physiology*; D017440:Photoperiod; D010879:Piperazines / Q000494:pharmacology; D011247:Pregnancy; D012160:Retina / Q000187:drug effects / Q000502:physiology*; D013997:Time Factors
chemical_list: D001549:Benzamides; D018491:Dopamine Agonists; C477501:N-((4-(2-cyanophenyl)-1-piperazinyl)methyl)-3-methylbenzamide; D010879:Piperazines; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D004298:Dopamine
keywords: circadian; dopamine; electroretinogram; photoperiod; retina; vision