Glutamate is the predominant excitatory transmitter in the central nervous system, and its cellular uptake is mediated by 5 excitatory amino acid transporters (EAAT1-5) that have distinct distribution patterns in mammalian brain. There are fundamental unanswered questions concerning the structure and function of glutamate transporters and their role in influencing the spatiotemporal profile of synaptically released glutamate. This application proposes to elucidate the molecular mechanisms underlying transporter gating and interaction with substrates, and to characterize the influence of the primary neuronal transporter (EAAT3) on synaptic transmission and synaptic plasticity in the hippocampus.
The specific aims are: 1. To elucidate the mechanism and molecular pharmacology of glutamate transport by identifying and characterizing the structural determinants involved in controlling substrate selectivity and pore access. 2. To test the hypothesis that the neuronal transporter EAAT3 limits activation of extrasynaptic receptors at the Schaeffer collateral-CA1 synapse in hippocampus and influences postsynaptic responses, plasticity, and behavior. The results of these studies will be of significance in neurobiology and medicine because they will provide new tools and insights into the molecular mechanism of glutamate transport and its roles in the brain. Elucidating the transporters' structure, mechanism, and physiological functions is necessary for understanding how they function in normal and pathophysiological processes and for developing new therapeutic strategies for diseases like amyotrophic lateral sclerosis, epilepsy, and stroke.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS033270-11
Application #
7263054
Study Section
Special Emphasis Panel (ZRG1-MDCN-F (03))
Program Officer
Silberberg, Shai D
Project Start
1995-06-01
Project End
2009-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
11
Fiscal Year
2007
Total Cost
$306,358
Indirect Cost
Name
University of Montana
Department
Other Health Professions
Type
Schools of Pharmacy
DUNS #
010379790
City
Missoula
State
MT
Country
United States
Zip Code
59812
Leary, Greg P; Allen, Jean E; Bunger, Peggy L et al. (2012) Single mutation to a sex pheromone receptor provides adaptive specificity between closely related moth species. Proc Natl Acad Sci U S A 109:14081-6
Stone, Emily; Hoffman, Katie; Kavanaugh, Michael (2012) Identifying neurotransmitter spill-over in hippocampal field recordings. Math Biosci 240:169-86
Leary, Greg P; Holley, David C; Stone, Emily F et al. (2011) The central cavity in trimeric glutamate transporters restricts ligand diffusion. Proc Natl Acad Sci U S A 108:14980-5
Sun, Weinan; Hoffman, Katie M; Holley, David C et al. (2011) Specificity and actions of an arylaspartate inhibitor of glutamate transport at the Schaffer collateral-CA1 pyramidal cell synapse. PLoS One 6:e23765
Holley, David C; Kavanaugh, Michael P (2009) Interactions of alkali cations with glutamate transporters. Philos Trans R Soc Lond B Biol Sci 364:155-61
Leary, Gregory P; Stone, Emily F; Holley, David C et al. (2007) The glutamate and chloride permeation pathways are colocalized in individual neuronal glutamate transporter subunits. J Neurosci 27:2938-42
Esslinger, C Sean; Agarwal, Shailesh; Gerdes, John et al. (2005) The substituted aspartate analogue L-beta-threo-benzyl-aspartate preferentially inhibits the neuronal excitatory amino acid transporter EAAT3. Neuropharmacology 49:850-61
Larsson, H Peter; Tzingounis, Anastassios V; Koch, Hans P et al. (2004) Fluorometric measurements of conformational changes in glutamate transporters. Proc Natl Acad Sci U S A 101:3951-6
Stein, Alex; Vaseduvan, Gayatri; Carter, Nicola S et al. (2003) Equilibrative nucleoside transporter family members from Leishmania donovani are electrogenic proton symporters. J Biol Chem 278:35127-34
Otis, T S; Kavanaugh, M P (2000) Isolation of current components and partial reaction cycles in the glial glutamate transporter EAAT2. J Neurosci 20:2749-57

Showing the most recent 10 out of 23 publications