The planned experiments explore the role of presynaptic ionotropic glutamate receptors in modulation of sensory input from peripheral nerves. This proposal aims, in the first place, at determining the distribution of presynaptic AMPA, kainate, and NMDA subunits in the dorsal horn of the spinal cord and in the dorsal column nuclei. I will also determine in what terminals are ionotropic receptors expressed presynaptically, i.e. in primary afferent terminals or also in terminals of interneurons, and if they might play a role in nociception and in presynaptic inhibition. I will determine the type/s of primary afferent terminal and of intrinsic terminals that express different subunits of presynaptic ionotropic glutamate receptors on the basis of morphology, neuroanatomical tracers, and co-expression of other markers suggestive of their functional properties. Finally, I will test the response of presynaptic ionotropic glutamate receptors to peripheral injury and inflammation. The work is based on a light and electron microscopic strategy that involves double- and multiple staining. We have introduced technical modifications, e.g. diluted fixation, without which the present proposal would not have been possible. Besides providing an essentially descriptive overview of the expression and distribution of subunits of the AMPA, kainate and NMDA, we will answer specific questions addressing the possible functional role of presynaptic receptors. These questions and the strategies to answer them are now specifically listed throughout the text and summarized in the conclusions of this revised proposal.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS012440-28
Application #
6916415
Study Section
Integrative, Functional and Cognitive Neuroscience 8 (IFCN)
Program Officer
Porter, Linda L
Project Start
1978-07-01
Project End
2008-06-30
Budget Start
2005-07-01
Budget End
2006-06-30
Support Year
28
Fiscal Year
2005
Total Cost
$277,400
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
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Lucifora, Simona; Willcockson, Helen H; Lu, Chun-Rong et al. (2006) Presynaptic low- and high-affinity kainate receptors in nociceptive spinal afferents. Pain 120:97-105
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Hwang, Se Jin; Burette, Alain; Rustioni, Aldo et al. (2004) Vanilloid receptor VR1-positive primary afferents are glutamatergic and contact spinal neurons that co-express neurokinin receptor NK1 and glutamate receptors. J Neurocytol 33:321-9
Lu, Chun-Rong; Hwang, Se Jin; Phend, Kristen D et al. (2003) Primary afferent terminals that express presynaptic NR1 in rats are mainly from myelinated, mechanosensitive fibers. J Comp Neurol 460:191-202
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Lu, Chun-Rong; Hwang, Se Jin; Phend, Kristen D et al. (2002) Primary afferent terminals in spinal cord express presynaptic AMPA receptors. J Neurosci 22:9522-9
Boukhelifa, M; Parast, M M; Valtschanoff, J G et al. (2001) A role for the cytoskeleton-associated protein palladin in neurite outgrowth. Mol Biol Cell 12:2721-9
Valtschanoff, J G; Rustioni, A; Guo, A et al. (2001) Vanilloid receptor VR1 is both presynaptic and postsynaptic in the superficial laminae of the rat dorsal horn. J Comp Neurol 436:225-35
Hwang, S J; Pagliardini, S; Rustioni, A et al. (2001) Presynaptic kainate receptors in primary afferents to the superficial laminae of the rat spinal cord. J Comp Neurol 436:275-89

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