The architectural complexity of the retina is brought about by a series of developmental events controlling"""""""" proliferation, fate determination, migration, process outgrowth, target recognition, synaptogenesis and cell death. These processes establish a precisely layered structure in which retinal neurons become positioned at different depths, connected via two intervening synaptic layers. Superimposed upon this layered organization, certain cell types are distributed as orderly arrays across a given layer so that they, and their processes, ensure a uniform sampling of the retinal surface as they establish connectivity with their afferent and target neurons. This research program is seeking to understand the cellular, molecular and genetic determinants of this patterning and connectivity in such arrays, focusing upon the population of horizontal cells. A quantitative trait analysis of horizontal cell number in recombinant inbred strains will first identify genes that control the size of this neuronal population. Chimeric mice will be produced from parental strains that differ in horizontal cell number, to determine whether dendritic field size is controlled by cell-intrinsic vs environmental instructions. A comparable quantitative trait analysis of the cone photoreceptors will also be conducted, and the role played by the afferents in specifying dendritic patterning of horizontal cells will be examined in various knockout and recombinant inbred strains in which the convergence ratio between cones and horizontal cells is modulated, or in which neurotransmissionbetween these afferents and the dendrites is altered or abolished. The roles played by both homotypic neighbors and by afferents in the establishment of this connectivity will be determined, examining the hypothesis that the onset of visual activity drives a competitive interaction between neighboring horizontal cells as they seek to colonize individual pedicles in the developing outer plexiform layer. Microarray analysis of embryonicretina from .two parental strains . showing a two-fold difference in both horizontal and cone cell number will be used to identify downstream genes critical for the establishment of these differences. These experiments will reveal the genes that regulate horizontal and cone cell number, as well as the biological mechanisms by which horizontal cells establish their morphological patterning, dendritic coverage and connectivity with cone afferents during development.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
3R01EY011087-09S1
Application #
7596763
Study Section
Biology and Diseases of the Posterior Eye Study Section (BDPE)
Program Officer
Greenwell, Thomas
Project Start
1996-12-01
Project End
2008-08-31
Budget Start
2007-09-01
Budget End
2008-08-31
Support Year
9
Fiscal Year
2008
Total Cost
$72,866
Indirect Cost
Name
University of California Santa Barbara
Department
Neurosciences
Type
Organized Research Units
DUNS #
094878394
City
Santa Barbara
State
CA
Country
United States
Zip Code
93106
Reese, Benjamin E; Keeley, Patrick W (2016) Genomic control of neuronal demographics in the retina. Prog Retin Eye Res 55:246-259
Keeley, Patrick W; Sliff, Buranee J; Lee, Sammy C S et al. (2012) Neuronal clustering and fasciculation phenotype in Dscam- and Bax-deficient mouse retinas. J Comp Neurol 520:1349-64
Reese, Benjamin E; Keeley, Patrick W; Lee, Sammy C S et al. (2011) Developmental plasticity of dendritic morphology and the establishment of coverage and connectivity in the outer retina. Dev Neurobiol 71:1273-85
Reese, Benjamin E (2011) Development of the retina and optic pathway. Vision Res 51:613-32
Petrs-Silva, Hilda; Dinculescu, Astra; Li, Qiuhong et al. (2011) Novel properties of tyrosine-mutant AAV2 vectors in the mouse retina. Mol Ther 19:293-301
Whitney, Irene E; Raven, Mary A; Ciobanu, Daniel C et al. (2011) Genetic modulation of horizontal cell number in the mouse retina. Proc Natl Acad Sci U S A 108:9697-702
Whitney, Irene E; Raven, Mary A; Lu, Lu et al. (2011) A QTL on chromosome 10 modulates cone photoreceptor number in the mouse retina. Invest Ophthalmol Vis Sci 52:3228-36
Keeley, Patrick W; Reese, Benjamin E (2010) Morphology of dopaminergic amacrine cells in the mouse retina: independence from homotypic interactions. J Comp Neurol 518:1220-31
Keeley, Patrick W; Reese, Benjamin E (2010) Role of afferents in the differentiation of bipolar cells in the mouse retina. J Neurosci 30:1677-85
Petrs-Silva, Hilda; Dinculescu, Astra; Li, Qiuhong et al. (2009) High-efficiency transduction of the mouse retina by tyrosine-mutant AAV serotype vectors. Mol Ther 17:463-71

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