GABAergic and glycinergic inhibitory pathways in the inner plexiform layer modulate the flow of visual information between bipolar cells and ganglion cells and are an essential element in retinal information processing. In mammalian retina the precise roles of the different inhibitory neurotransmitters, receptor subtypes and circuits are not well understood. Different bipolar cell types separate the visual signal into distinct visual channels, e.g., rod versus cone, on versus off and sustained versus transient signals. Distinct GABAA and GABAC receptors found on bipolar cell terminals have been shown to have different biophysical properties and are present in different proportions on distinct cell types. Glycine receptors have also been shown to be present on bipolar cell terminals, but their functional roles on most bipolar cells is unclear. The goal of the proposed study is to analyze the role of GABAergic and glycinergic inhibition of bipolar cell terminals on spatial and temporal processing in the IPL. We will measure the light-evoked inhibitory signals in different bipolar cell types to determine whether these distinct receptor types mediate unique inhibitory signals and whether the distinct bipolar cell signaling pathways utilize distinct inhibitory signals, which affects transmission from bipolar cells to third order cells

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Postdoctoral Individual National Research Service Award (F32)
Project #
5F32EY015629-02
Application #
6881646
Study Section
Special Emphasis Panel (ZRG1-F03B (20))
Program Officer
Hunter, Chyren
Project Start
2004-03-12
Project End
2006-03-11
Budget Start
2005-03-12
Budget End
2006-03-11
Support Year
2
Fiscal Year
2005
Total Cost
$48,296
Indirect Cost
Name
Washington University
Department
Ophthalmology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Eggers, Erika D; McCall, Maureen A; Lukasiewicz, Peter D (2007) Presynaptic inhibition differentially shapes transmission in distinct circuits in the mouse retina. J Physiol 582:569-82
Eggers, Erika D; Lukasiewicz, Peter D (2006) Receptor and transmitter release properties set the time course of retinal inhibition. J Neurosci 26:9413-25
Eggers, Erika D; Lukasiewicz, Peter D (2006) GABA(A), GABA(C) and glycine receptor-mediated inhibition differentially affects light-evoked signalling from mouse retinal rod bipolar cells. J Physiol 572:215-25
Lukasiewicz, Peter D; Eggers, Erika D; Sagdullaev, Botir T et al. (2004) GABAC receptor-mediated inhibition in the retina. Vision Res 44:3289-96