Sunday, September 28, 2025 9/28/2025

VISUAL SYSTEM SYNAPSES AND CIRCUITS

Award Number: R01EY003592
ORGANIZATION: NATIONAL EYE INSTITUTE
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)
PERIOD OF PERFORMANCE START DATE: 02/01/1981
PERIOD OF PERFORMANCE END DATE: 03/31/2015

Group Awards By:

View Award Description

VISUAL SYSTEM SYNAPSES AND CIRCUITS - DESCRIPTION (provided by applicant): We will analyze the actions of genes that regulate how photoreceptor synapses in Drosophila form and function, and how these contribute to circuits of neurons in the fly's visual system. Projects focus on the photoreceptor target interneuron in the first and second neuropils, the lamina and medulla, functional counterparts to the outer and inner plexiform layers of the retina. A long-term objective is to understand the organization of multiple-contact synapses (such as dyads and triads) from the fly's photoreceptor tetrad synapses. More recent objectives are to understand how these form and then contribute to the visual system's synaptic microcircuits. Current objectives are to study axon targeting prior to photoreceptor synaptogenesis, and the action of crumbs in directing growth cone trajectories. The numbers and types of feedback photoreceptor synapses will be studied using genetic reagents to label and identify participating neurons at EM level, and the involvement of Kirre and Irrec-like proteins as well as Dscam cell adhesion molecules in establishing the specificity of synapses between two types of lamina feedback interneuron, L2 and L4, as well as in regulating reciprocity between these. The projects use mutants and knockdowns of the corresponding genes, and other genetic reagents. Synaptic function will be examined from mutants that alter the synaptic vesicle phenotype of photoreceptors, or the targeting of their terminals, as well as the recycling of neurotransmitter, histamine, through a beta-alanyl conjugation pathway. Pathway strength for photoreceptor feedback will be evaluated from synapse numbers in different mutant backgrounds to reveal the network regulation of synaptic circuits. These projects examine mutant photoreceptors using advanced methods of serial-section and immuno-EM, and skilled personnel to implement these. Analysis of synaptic circuits in the complex medulla will continue, using serial-EM to identify actual circuits between identified neurons of the pathways underlying spectral discrimination. These data will be used to examine the neural basis of color vision; to identify circuit design and the frequencies of network motifs in synaptic circuits; and to examine the regulation that these undergo in both the lamina and medulla when contributing neurons are eliminated or genetically transformed. The proposed studies will identify the cellular mechanisms for synaptic function and organization in visual systems, and the rearrangements these undergo in functional and disease states of the retina, and will be identified from their genetic bases in a model visual system with marked similarities to the retina. PUBLIC HEALTH RELEVANCE: The studies aim to produce a basic model of synaptogenesis applicable to polyadic synapses like the retina's dyads and triads, and identify underlying genetic bases for changes that result from congenital or dystrophic diseases, or retinal damage, and the regulation of the retina's synaptic networks. The projects analyze how anatomical synaptic circuits, many with counterparts in the retina, give rise to modules of visual behavior.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2013 ( Subtotal = $184,290 )
2013	2013	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	001	33	6/6/2013	EXTENSION WITH OR WITHOUT FUNDS	$9,699
2013	2013	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	000	33	3/11/2013	EXTENSION WITH OR WITHOUT FUNDS	$174,591
														Subtotal = $184,290

Issue Date FY: 2012 ( Subtotal = $193,990 )
2012	2012	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	000	32	3/23/2012	NON-COMPETING CONTINUATION	$193,990
														Subtotal = $193,990

Issue Date FY: 2011 ( Subtotal = $194,692 )
2011	2011	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	000	31	3/9/2011	COMPETING CONTINUATION	$194,692
														Subtotal = $194,692

Issue Date FY: 2010 ( Subtotal = $233,593 )
2010	2010	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	000	30	3/12/2010	NON-COMPETING CONTINUATION	$233,593
														Subtotal = $233,593

Issue Date FY: 2009 ( Subtotal = $235,953 )
2009	2009	DALHOUSIE UNIVERSITY	1355 Oxford Street	HALIFAX, N S				CAN	Vision Research	000	29	6/19/2009	NON-COMPETING CONTINUATION	$235,953
														Subtotal = $235,953

Issue Date FY: 2007 ( Subtotal = $235,953 )
2007	2007	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	27	3/29/2007	NON-COMPETING CONTINUATION	$235,953
														Subtotal = $235,953

Issue Date FY: 2006 ( Subtotal = $268,000 )
2006	2006	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	26	5/12/2006	COMPETING CONTINUATION	$268,000
														Subtotal = $268,000

Issue Date FY: 2005 ( Subtotal = $200,000 )
2005	2005	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	25	3/3/2005	NON-COMPETING CONTINUATION	$200,000
														Subtotal = $200,000

Issue Date FY: 2004 ( Subtotal = $200,000 )
2004	2004	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	24	4/22/2004	NON-COMPETING CONTINUATION	$200,000
														Subtotal = $200,000

Issue Date FY: 2003 ( Subtotal = $200,000 )
2003	2003	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	23		NON-COMPETING CONTINUATION	$200,000
														Subtotal = $200,000

Issue Date FY: 2002 ( Subtotal = $200,000 )
2002	2002	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	22	2/18/2002	COMPETING CONTINUATION	$200,000
														Subtotal = $200,000

Issue Date FY: 2001 ( Subtotal = $132,175 )
2001	2001	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	21	3/19/2001	NON-COMPETING CONTINUATION	$132,175
														Subtotal = $132,175

Issue Date FY: 2000 ( Subtotal = $133,062 )
2000	2000	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	20	3/8/2000	NON-COMPETING CONTINUATION	$133,062
														Subtotal = $133,062

Issue Date FY: 1999 ( Subtotal = $135,647 )
1999	1999	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	19	3/1/1999	COMPETING CONTINUATION	$135,647
														Subtotal = $135,647

Issue Date FY: 1998 ( Subtotal = $113,922 )
1998	1998	DALHOUSIE UNIVERSITY	**	HALIFAX, N S		00000		CAN	Vision Research	000	18	2/27/1998	NON-COMPETING CONTINUATION	$113,922
														Subtotal = $113,922

Grand Total All Awards = $2,861,277

Top

All Categories

About

Search

Reports

Data Submission

Award Information

VISUAL SYSTEM SYNAPSES AND CIRCUITS

Award Number: R01EY003592

ORGANIZATION: NATIONAL EYE INSTITUTE

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

PERIOD OF PERFORMANCE START DATE: 02/01/1981

PERIOD OF PERFORMANCE END DATE: 03/31/2015

Federal Websites

Department of Health & Human Services

HHS Operating Divisions

HHS Staff Divisions

Download A Document Viewer