The overall goal of this proposal is to improve our understanding of the peripheral and central mechanisms of visceral pain processing. More specifically this project proposes to study the peripheral events that might lead to activation of visceral nociceptive afferents (both sympathetic and vagal) from the heart, lungs and esophagus using selective natural mechanical (graded pressure distention) and algesic chemical stimuli (intra-atrial, pericardial or aerosol administration to the esophagus and tracheo-bronchial tree of 5-HT, bradykinin, adenosine, histamine or PGE2). Later experiments will begin to examine the central visceral representation of these stimuli. In this application it is proposed to use a multi-disciplinary approach incorporating a variety of anatomical, pharmacological, behavioral and eletrophysiological techniques to answer four specific aims: (1) to examine and define the precise location of action of chemical and mechanical stimuli within specific organs of the thoracic viscera (i.e., heart, lungs or esophagus). (2) to characterize the adequate nociceptive stimulus, either chemical and/or mechanical, for these organs and examine potential interactions between these stimuli. (3) to define the precise afferent pathway for each of these noxious stimuli from the heart, lungs and esophagus, and examine interactions between sympathetic and vagal afferents. (4) to examine the neural substrates and the central pathways involved in mediating, or modulating, visceral pain of cardiac, respiratory or esophageal origin. This proposal represents the first systematic examination of thoracic visceral nociceptive mechanisms and will likely yield new and valuable information concerning the relative importance of chemical and mechanical activation of vagal and sympathetic afferents in mediating pain from the heart, lungs and esophagus and of the central representation and processing of noxious visceral information from the thorax.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29NS029844-02
Application #
3478384
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1991-07-18
Project End
1996-06-30
Budget Start
1992-07-01
Budget End
1993-06-30
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost
Name
University of Iowa
Department
Type
Schools of Medicine
DUNS #
041294109
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Meller, S T; Dykstra, C; Gebhart, G F (1996) Acute mechanical hyperalgesia in the rat can be produced by coactivation of spinal ionotropic AMPA and metabotropic glutamate receptors, activation of phospholipase A2 and generation of cyclooxygenase products. Prog Brain Res 110:177-92
Meller, S T; Dykstra, C; Gebhart, G F (1996) Acute thermal hyperalgesia in the rat is produced by activation of N-methyl-D-aspartate receptors and protein kinase C and production of nitric oxide. Neuroscience 71:327-35
Maves, T J; Gebhart, G F; Meller, S T (1995) Continuous infusion of acidified saline around the rat sciatic nerve produces thermal hyperalgesia. Neurosci Lett 194:45-8
McDermott, D A; Meller, S T; Gebhart, G F et al. (1995) Use of an indwelling catheter for examining cardiovascular responses to pericardial administration of bradykinin in rat. Cardiovasc Res 30:39-46
Meller, S T; Dykstra, C L; Gebhart, G F (1994) Investigations of the possible role for carbon monoxide (CO) in thermal and mechanical hyperalgesia in the rat. Neuroreport 5:2337-41
Euchner-Wamser, I; Meller, S T; Gebhart, G F (1994) A model of cardiac nociception in chronically instrumented rats: behavioral and electrophysiological effects of pericardial administration of algogenic substances. Pain 58:117-28
Meller, S T; Cummings, C P; Traub, R J et al. (1994) The role of nitric oxide in the development and maintenance of the hyperalgesia produced by intraplantar injection of carrageenan in the rat. Neuroscience 60:367-74
Meller, S T; Dykstra, C; Grzybycki, D et al. (1994) The possible role of glia in nociceptive processing and hyperalgesia in the spinal cord of the rat. Neuropharmacology 33:1471-8
Meller, S T; Gebhart, G F (1994) Spinal mediators of hyperalgesia. Drugs 47 Suppl 5:10-20;discussion 46-7
Traub, R J; Lim, F; Sengupta, J N et al. (1994) Noxious distention of viscera results in differential c-Fos expression in second order sensory neurons receiving 'sympathetic' or 'parasympathetic' input. Neurosci Lett 180:71-5

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