David L. Deitcher
Professor
David L. Deitcher

Phone

607-254-4315
Fax: 607-254-1303

Address

Department of Neurobiology & Behavior
W125 Seeley G. Mudd Hall
Cornell University
Ithaca, NY 14853-2703

Email

Web Sites

Department Profile

Research Description

The vesicular release of neurotransmitters at the synapse is the major way that neurons communicate with each other. Three proteins: Syntaxin, SNAP-25, and synaptobrevin are thought to be crucial for the process of neurotransmitter release. These proteins are known collectively as the SNAREs and they form a very stable SNARE complex through the interaction of amphipathic helices. How does the formation of this protein complex correspond to the process of neurotransmitter release? What is the function of these proteins in neurotransmitter release? The Deitcher laboratory is studying the function of these presynaptic proteins in the genetically amenable organism Drosophila melanogaster to answer these questions. By generating mutations in the genes encoding presynaptic proteins, the lab is defining the function of specific synaptic proteins in neurotransmitter and neuropeptide release. We are currently concentrating our efforts on the role of the protein SNAP-25 in neurotransmitter release. We have identified a temperature-sensitive mutant in SNAP-25, SNAP-25ts. This mutation results in an increase in neurotransmitter release at room temperature but it decreases the stability of the SNARE complex. SNARE complexes containing SNAP-25ts also appear to be in a more relaxed conformation than those complexes containing wild type SNAP-25 protein. We are currently examining the relationship between SNARE conformation and vesicle fusion using additional SNAP-25 alleles and by transgenic expression of SNAP-25 cDNAs containing site-directed mutations.

The laboratory is also examining the role of the SNARE proteins in neuropeptide release using a novel GFP-tagged neuropeptide transgenic system. This system allows us to quantitate neuropeptide release optically in situ.

The Deitcher laboratory is also examining the formation of synapses in adult flies. Synapse formation is well-studied in Drosophila larvae but the mechanisms governing the formation of adult synapses in the fly have not been examined. Our evidence indicates that the process of synaptogenesis in the larva and adult differ in substantial ways. We are also interested in how synapses change as the fly ages. This is potentially a useful system for modeling aging and neurodegeneration in humans.

Selected Publications

  • Vilinsky, I., Stewart, B., Drummond, J., Robinson, I., and Deitcher, D. (2002) A Drosophila SNAP-25 Null Mutant Reveals Context-Dependent Redundancy With SNAP-24 In Neurotransmission. Genetics 162, 259-271.
  • Deitcher, D (2002) Effective Mining of Information in Sequence Databases. In: Bioinformatics 2002: A Neuroscientist's Guide to Tools and Techniques for Mining and Refining Massive Data Sets, Williams and Goldowitz, eds, Society for Neuroscience, Washington.
  • Deitcher, D (2002) Exocytosis, endocytosis, and development. Seminars in Cell and Developmental Biology, 13, 71-76.
  • Stewart, B., Mohtashami, M., Rivlin, P., Deitcher, D., Trimble, W., and Boulianne, G. (2002) Disruption of Synaptic Structure and Function by Mutant NSF at Drosophila Neuromuscular Synapses. J. Neurobiol., 51, 261-271.
  • Rao, S, Stewart, B, Rivlin, P, Vilinsky, I, Watson, B, Lang, C, Boulianne, G, Salpeter, M, and Deitcher, D (2001) Two Distinct Effects on Neurotransmission in a Temperature-Sensitive SNAP-25 Mutant. EMBO J, 20, 6761-6771.
  • Watson, B, Vilinsky, I, and Deitcher, D (2001) Generation of a Semi-Dominant Mutation with Temperature Sensitive Effects on Both Locomotion and Phototransduction in Drosophila Melanogaster. J. Neurgenet., 15, 75-95.
  • Forlano, P, Deitcher, D, Myers, D, and Bass, A (2001) Anatomical distribution and cellular basis for high levels of estrogen synthesis in the brain of teleost fish: aromatase enzyme and mRNA expression identify glia as source. J. Neurosci., 21, 8943-8955.
  • Rao, S, Lang, C, Levitan, E, and Deitcher, D (2001) Visualization of Neuropeptide Expression, Transport, and Exocytosis in Drosophila melanogaster. J. Neurobiol. 49, 159-172.
  • Deitcher, D (2001) shibire's enhancer is Cancer's Suppressor. TINS, 24, 625-626.
  • Sucher, N, Deitcher, D, Baro, D, Harris-Warrick, R, Guenther, E (2000) Genes and Channels: Patch/Voltage-Clamp Analysis and Single Cell RT-PCR. Cell Tissue Res. 302, 295-307.

Movement of Secretory Granules Across an Axon. View Movie
Movement of Secretory Granules in Synaptic Boutouns. View Movie