The long term goal of this project is to explore the physiology and functional roles of the intrinsically photosensitive retinal ganglion cells (ipRGCs). The present proposal is to investigate the interactions of ipRGCs with key processes in the developing retina. The ipRGCs are the first functional photoreceptors of the mammalian retina, generating electrical responses to light more than a week before rod and cone photoreceptors are mature enough to affect retinal output. At this age, ganglion cell axons are already establishing and refining their central projections to the visual centers of the brain. This process is thought to be dependent on retinal activity, especially the waves of electrical activity that sweep across the inner retina. During a critical developmental stage (first postnatal week in mice), retinal waves are driven by a network of cholinergic (starburst) amacrine cells which excite each other as well as ganglion cells through nicotinic receptors. These ?Stage II? retinal waves have been considered immune from photic influence due to the immaturity of the classical photoreceptors. However, our preliminary evidence shows that light does, in fact, modulate the behavior of Stage II retinal waves and this influence requires melanopsin, the photopigment of ipRGCs. In return, the waves excite ipRGCs. These bidirectional interactions between retinal waves and ipRGCs are unexpected, and have significant implications for visual system development. The central focus of this renewal application is to explore the nature, mechanisms and functional implications of the bidirectional interactions between ipRGCs and Stage II retinal waves.
The specific aims of the proposal are: 1) to determine the synaptic mechanisms by which waves excite melanopsin ganglion cells and how the waves shape the central projections of ipRGCs;and 2) to assess the impact of ipRGCs on retinal waves, the mechanisms responsible for these effects, and their impact on development of retinal projections to central visual targets. Proposed studies will be conducted in wildtype and genetically modified mice and will involve in vitro recordings and pharmacological manipulation of retinal neurons;gene expression profiling;and tracing of retinofugal projections. These studies will help to document an important and novel functional role for ganglion cell photoreceptors, and will clarify mechanisms responsible for their surprising influence on other retinal neurons. They will refine our understanding of the role of lightdriven activity in visual system development and may prompt a reconsideration of the possible impact of lighting environments on visual system development in premature human infants.

Public Health Relevance

This project will assess the effects of light on electrical activity in the developing retina and the role of a newly discovered light-sensitive retinal cell in this process. Such activity is crucial for the normal development and function of the visual regions of the brain, so disturbances in this process, as may occur in premature infants, could have negative effects on the health of the visual system.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY017137-09
Application #
8721961
Study Section
Biology and Diseases of the Posterior Eye (BDPE)
Program Officer
Greenwell, Thomas
Project Start
2006-02-01
Project End
2015-08-31
Budget Start
2014-09-01
Budget End
2015-08-31
Support Year
9
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Brown University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
City
Providence
State
RI
Country
United States
Zip Code
02912
Fernandez, Diego Carlos; Fogerson, P Michelle; Lazzerini Ospri, Lorenzo et al. (2018) Light Affects Mood and Learning through Distinct Retina-Brain Pathways. Cell 175:71-84.e18
Chew, Kylie S; Renna, Jordan M; McNeill, David S et al. (2017) A subset of ipRGCs regulates both maturation of the circadian clock and segregation of retinogeniculate projections in mice. Elife 6:
Sabbah, Shai; Berg, Daniel; Papendorp, Carin et al. (2017) A Cre Mouse Line for Probing Irradiance- and Direction-Encoding Retinal Networks. eNeuro 4:
Lessieur, Emma M; Fogerty, Joseph; Gaivin, Robert J et al. (2017) The Ciliopathy Gene ahi1 Is Required for Zebrafish Cone Photoreceptor Outer Segment Morphogenesis and Survival. Invest Ophthalmol Vis Sci 58:448-460
Walker, Marquis T; Rupp, Alan; Elsaesser, Rebecca et al. (2015) RdgB2 is required for dim-light input into intrinsically photosensitive retinal ganglion cells. Mol Biol Cell 26:3671-8
Renna, Jordan M; Chellappa, Deepa K; Ross, Christopher L et al. (2015) Melanopsin ganglion cells extend dendrites into the outer retina during early postnatal development. Dev Neurobiol 75:935-46
Lucas, Robert J; Peirson, Stuart N; Berson, David M et al. (2014) Measuring and using light in the melanopsin age. Trends Neurosci 37:1-9
Weng, Shijun; Estevez, Maureen E; Berson, David M (2013) Mouse ganglion-cell photoreceptors are driven by the most sensitive rod pathway and by both types of cones. PLoS One 8:e66480
Van Hook, Matthew J; Wong, Kwoon Y; Berson, David M (2012) Dopaminergic modulation of ganglion-cell photoreceptors in rat. Eur J Neurosci 35:507-18
Renna, Jordan M; Weng, Shijun; Berson, David M (2011) Light acts through melanopsin to alter retinal waves and segregation of retinogeniculate afferents. Nat Neurosci 14:827-9

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