| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Department of Biological Sciences, Michigan Technological University, Houghton, MI, USA
2 Casualty Care, U.S. Army Institute of Surgical Research, Fort Sam Houston, TX, USA
3 Departments of Medicine and Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, USA
* To whom correspondence should be addressed. E-mail: jcarter{at}mtu.edu.
Autonomic responses may underlie associations among anxiety, vestibular dysfunction, and unexplained syncope. Mental stress (MS), an anxiety-inducing
stimulus, causes forearm vasodilation, whereas the vestibulosympathetic reflex(VSR) causes forearm vasoconstriction. The purpose of this study was to
examine the combined effects of mental and vestibular stimulation on neurovascular control in the forearm. Heart rate, arterial pressure (Finapres), and forearm blood flow (ATL Doppler) were measured in 10 healthy volunteers in the
prone position during 1) head-down rotation (HDR), 2) MS (mental arithmetic), and 3) combined HDR and MS. Forearm vascular resistance (FVR) increased during HDR (70±12 to 96±16 mmHg/ml/min) and decreased during MS (78±17 to 46±7 mmHg/ml/min). During the combined HDR and MS trial, FVR did not change (
-9±15 mmHg/ml/min) and was not significantly different from the algebraic sum of each trial performed alone (-6±13 mmHg/ml/min). Arm muscle sympathetic nerve activity (MSNA; microneurography) was measured in seven additional subjects. MSNA increased during HDR (13±2 to 17±2 bursts/min) and the combined HDR and MS trial (11±2 to 16±2 bursts/min). Increases in MSNA during the combination trial (5±2 bursts/min) were not different from the algebraic sum of each trial performed alone (6±2 bursts/min). We conclude an additive neurovascular interaction exists between MS and the VSR in the forearm. Activation of the VSR prevented forearm vasodilation during MS, suggesting that activation of the VSR may help protect against stress-induced syncope.
This article has been cited by other articles:
|
|
 |
|
  N. T. Kuipers, C. L. Sauder, J. R. Carter, and C. A. Ray Neurovascular responses to mental stress in the supine and upright postures J Appl Physiol, April 1, 2008; 104(4): 1129 - 1136. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. R. Carter and C. A. Ray Sympathetic responses to vestibular activation in humans Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R681 - R688. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. E. Wilson, C. L. Sauder, M. L. Kearney, N. T. Kuipers, U. A. Leuenberger, K. D. Monahan, and C. A. Ray Skin-surface cooling elicits peripheral and visceral vasoconstriction in humans J Appl Physiol, October 1, 2007; 103(4): 1257 - 1262. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Dyckman, K. D. Monahan, and C. A. Ray Effect of baroreflex loading on the responsiveness of the vestibulosympathetic reflex in humans J Appl Physiol, September 1, 2007; 103(3): 1001 - 1006. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Noto, T. Sato, M. Kudo, K. Kurata, and K. Hirota The Relationship Between Salivary Biomarkers and State-Trait Anxiety Inventory Score Under Mental Arithmetic Stress: A Pilot Study. Anesth. Analg., December 1, 2005; 101(6): 1873 - 1876. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
