Retinal Dopamine Mediates Multiple Dimensions of Light-Adapted Vision

• Authors: Chad R. Jackson, Vanderbilt University; Guo-Xiang Ruan, Vanderbilt University; Fazila Aseem, Emory University; Jane Abey, Emory University; Karen Gamble, University of Alabama-Birmingham; Greg Stanwood, Vanderbilt University School of Medicine; Richard D. Palmiter, University of Washington; P Michael Iuvone, Emory University; Douglas G. McMahon, Vanderbilt University
• Journal Title: Journal of Neuroscience Nursing
• Volume: Volume 32, Number 27
• Publisher: Society for Neuroscience | 2012-07-04, Pages 9359-9368
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1523/JNEUROSCI.0711-12.2012
• Subjects: Biology, Neuroscience

Abstract

Dopamine is a key neuromodulator in the retina and brain that supports motor, cognitive and visual function. Here, we developed a mouse model, on a C57 background, in which expression of the rate-limiting enzyme for dopamine synthesis, tyrosine hydroxylase, is specifically disrupted in the retina. This model enabled assessment of the overall role of retinal dopamine in vision using electrophysiological (electroretinogram), psychophysical (optokinetic tracking) and pharmacological techniques. Significant disruptions were observed in high-resolution, light-adapted vision caused by specific deficits in light responses, contrast sensitivity, acuity and circadian rhythms in this retinal dopamine-depleted mouse model. These global effects of retinal dopamine on vision are driven by the differential actions of dopamine D1 and D4 receptors on specific retinal functions and appear to be due to the ongoing bioavailability of dopamine, rather than developmental effects. Taken together, our data indicate that dopamine is necessary for the circadian nature of light-adapted vision, as well as optimal contrast detection and acuity.