The objective of this proposal is to gain knowledge about the organization of visceral sensory processing in the upper cervical spinal cord. Recent observations led to the concept that this region may integrate visceral information to modulate nociceptive responses. Preliminary evidence in rats suggests that upper cervical neurons with descending projections process noxious inputs to produce inhibitory effects on sensory transmission in lower segments. Additionally a group of descending neurons in C1-C2 segments have respiration-phased discharge. No clear contribution to normal breathing has been found for these neurons. A possible function that has not been considered previously is that visceral input to high cervical respiratory neurons may influence the descending outflow to produce the sensation of dyspnea. The overall hypothesis is that upper cervical neurons with descending projections are excited by visceral spinal input and vagal input, and thus could modulate neuronal activity in lower spinal segments.
Specific aims are designed to answer the following questions: 1) What is the anatomical distribution and neurochemical content of upper cervical propriospinal neurons? 2) Does chemical activation/inactivation of upper cervical neurons affect spinoparabrachial or spinothalamic tract neurons in thoracic and lumbosacral segments? 3) Are C1-C2 descending propriospinal neurons, including respiratory neurons, excited by visceral afferent inputs? 4) What are the electrophysiologic, morphologic and neurochemical characteristics of single C1-C2 neurons examined after intracellular penetration? Neuroanatomical, immunohistochemical and neurophysiological techniques will be used to determine basic information about upper cervical propriospinal neurons, including respiratory neurons. Data derived from these studies will provide understanding of central neural mechanisms which may be involved in conditions such as autonomic dysreflexia, silent myocardial ischemia, and dyspnea.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS035471-02
Application #
2460655
Study Section
Respiratory and Applied Physiology Study Section (RAP)
Program Officer
Baughman, Robert W
Project Start
1996-09-01
Project End
2000-07-31
Budget Start
1997-08-01
Budget End
1998-07-31
Support Year
2
Fiscal Year
1997
Total Cost
Indirect Cost
Name
University of Oklahoma Health Sciences Center
Department
Physiology
Type
Schools of Medicine
DUNS #
937727907
City
Oklahoma City
State
OK
Country
United States
Zip Code
73117
Ardell, J L; Andresen, M C; Armour, J A et al. (2016) Translational neurocardiology: preclinical models and cardioneural integrative aspects. J Physiol 594:3877-909
Ghorbani, Marie Louise M; Qin, Chao; Wu, Mingyuan et al. (2011) Characterization of upper thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in diabetic rats. Auton Neurosci 165:168-77
Qin, Chao; Goodman, Melanie D; Little, Janine M et al. (2010) Comparison of activity characteristics of the cuneate nucleus and thoracic spinal neurons receiving noxious cardiac and/or somatic inputs in rats. Brain Res 1346:102-11
Goodman-Keiser, Melanie D; Qin, Chao; Thompson, Ann M et al. (2010) Upper thoracic postsynaptic dorsal column neurons conduct cardiac mechanoreceptive information, but not cardiac chemical nociception in rats. Brain Res 1366:71-84
Gao, Jie; Wu, Mingyuan; Li, Linggen et al. (2010) Effects of spinal cord stimulation with ""standard clinical"" and higher frequencies on peripheral blood flow in rats. Brain Res 1313:53-61
Qin, Chao; Malykhina, Anna P; Thompson, Ann M et al. (2010) Cross-organ sensitization of thoracic spinal neurons receiving noxious cardiac input in rats with gastroesophageal reflux. Am J Physiol Gastrointest Liver Physiol 298:G934-42
Qin, C; Yang, X; Wu, M et al. (2009) Modulation of neuronal activity in dorsal column nuclei by upper cervical spinal cord stimulation in rats. Neuroscience 164:770-6
Qin, Chao; Du, Jian-qing; Tang, Jing-shi et al. (2009) Bradykinin is involved in the mediation of cardiac nociception during ischemia through upper thoracic spinal neurons. Curr Neurovasc Res 6:89-94
Qin, Chao; Ghorbani, Marie L M; Wu, Mingyuan et al. (2009) Characterization of upper thoracic spinal neurons responding to esophageal distension in diabetic rats. Auton Neurosci 145:27-34
Wu, Mingyuan; Linderoth, Bengt; Foreman, Robert D (2008) Putative mechanisms behind effects of spinal cord stimulation on vascular diseases: a review of experimental studies. Auton Neurosci 138:9-23

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