This project will examine the cellular and molecular mechanisms that govern the establishment and plasticity of synapses in a model genetic system, the Drosophila neuromuscular junction. These problems will be studied using manipulations at the cellular and molecular level, applied with single cell precision during embryonic and larval development. We have previously characterized several of the cellular events involved in the establishment and growth of the synapse. We are now poised to apply novel tools, developed in the lab, to test hypotheses about the role of electrical activity during neuromuscular development and functional plasticity. The methods include the use """"""""Electrical Knock Out"""""""" or EKO ion channels, that suppress electrical activity in specific motoneurons and/or muscle fibers. There are four specific goals in this proposal. First, we plan to expand our repertoire of tools for controlling electrical activity in vivo to include channel constructs enhance electrical activity, providing a complementary set of tools to the EKO constructs. Second, using these methods, several hypotheses about the roles of electrical activity in regulating neuromuscular connectivity and synaptic refinement during embryogenesis and larval development will be tested. Third, the role of neuromuscular activity in regulating the functional plasticity of the synapse will be examined. The latter analysis will focus on the putative orthograde and retrograde signals which are proposed to regulate a form of synaptic homeostasis at the neuromuscular junction. Finally, by focally control electrical activity in specific cells, we propose to carry out a genetic screen to identify the molecules whose functions are involved in regulating synaptic development and plasticity. The many molecular-genetic tools available in Drosophila, combined with vital imaging and electrophysiological analyses, makes this system particularly well-suited to uncover the molecular mechanisms that govern synaptic development and dynamic functional plasticity.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS031651-11
Application #
6637359
Study Section
Special Emphasis Panel (ZRG1-MDCN-7 (01))
Program Officer
Porter, Linda L
Project Start
1993-05-01
Project End
2005-07-31
Budget Start
2003-08-01
Budget End
2004-07-31
Support Year
11
Fiscal Year
2003
Total Cost
$277,799
Indirect Cost
Name
Yale University
Department
Physiology
Type
Schools of Arts and Sciences
DUNS #
043207562
City
New Haven
State
CT
Country
United States
Zip Code
06520
Vonhoff, Fernando; Keshishian, Haig (2017) In Vivo Calcium Signaling during Synaptic Refinement at the Drosophila Neuromuscular Junction. J Neurosci 37:5511-5526
Vonhoff, Fernando; Keshishian, Haig (2017) Cyclic nucleotide signaling is required during synaptic refinement at the Drosophila neuromuscular junction. Dev Neurobiol 77:39-60
Berke, Brett; Wittnam, Jessica; McNeill, Elizabeth et al. (2013) Retrograde BMP signaling at the synapse: a permissive signal for synapse maturation and activity-dependent plasticity. J Neurosci 33:17937-50
Olsen, Douglas P; Keshishian, Haig (2012) Experimental methods for examining synaptic plasticity in Drosophila. Cold Spring Harb Protoc 2012:162-73
Berke, Brett; Keshishian, Haig (2011) Cracking the combinatorial semaphorin code. Neuron 70:175-7
Leiserson, William M; Keshishian, Haig (2011) Maintenance and regulation of extracellular volume and the ion environment in Drosophila larval nerves. Glia 59:1312-21
Leiserson, William M; Forbush, Biff; Keshishian, Haig (2011) Drosophila glia use a conserved cotransporter mechanism to regulate extracellular volume. Glia 59:320-32
Carrillo, Robert A; Olsen, Douglas P; Yoon, Kenneth S et al. (2010) Presynaptic activity and CaMKII modulate retrograde semaphorin signaling and synaptic refinement. Neuron 68:32-44
Nicholson, Louise; Singh, Gunisha K; Osterwalder, Thomas et al. (2008) Spatial and temporal control of gene expression in Drosophila using the inducible GeneSwitch GAL4 system. I. Screen for larval nervous system drivers. Genetics 178:215-34
Fernandes, Joyce J; Keshishian, Haig (2005) Motoneurons regulate myoblast proliferation and patterning in Drosophila. Dev Biol 277:493-505

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