Name P. Liam Oey
Department Neurology and Neurosurgery
Section neuromuscular diseases
Function Associate prof
Neurologist/Clinical Neurophysiologist
E-mail:
p.l.oey@umcutrecht.nl
Telephone number: +31 88 7557962
Title research line
1.Micro-neurographic recordings for system identification of the neuromuscular system.
This project is a joint project of the University of Twente and the UMC Utrecht, in collaboration with the TU Delft.
2. Interaction of gastrointestinal and cardiovascular autonomic nervous systems
This project is a joint project of the Department Neurology and Gastrointestinal Research Unit, Department of Gastroenterology and Surgery UMC Utrecht.
3. Role of sympathetic nervous system in the pathogenesis of renal-hypertension
This project is a joint project of the Department Neurology and Department Nephrology UMC Utrecht.
Summary research 1. Human muscle reflexes can be regarded as closed loop control systems, consisting of muscles (actuators), the central nervous system (controller) and the muscle mechanoreceptors, notably the muscle spindles and Golgi tendon organs. The mechanoreceptors are sensitive to length, velocity and force. To understand this reflex system, mathematical physiological models can be used. The model parameters can be estimated by applying mechanical stimuli to subjects, using robotic manipulators and measuring the applied force, position and EMG. With this method, it has for instance been shown that the loop-gain of the reflex control loop can vary, depending on the task given to the subject (e.g. hold this position, or: maintain a steady force). However, this method can not discriminate between the effects of muscle mechanoreceptors and the central nervous system, since there is no information about the mechanoreceptor output. Microneurography, in which a micro-electrode is inserted in a nerve bundle, can be used to measure mechanoreceptor signals.
2. The enteric nervous system is usually described as being a separate and independent entity. The interaction between this enteric system and cardiovascular system is studied by continuous recording of ECG, blood pressure and Muscle Sympathetic Nerve Activity (microneurography) during gastric distention and meal in young- and older healthy subjects as well as patients with irritable bowel syndrome and postprandial hypotension.
3. Microneurography is a method to investigate directly efferent and afferent neural traffic in unmyelinated C fibers and provides direct information about neural control of autonomic effector’s organs including blood vessels and sweat glands. Sympathetic microneurography has become a potent tool to reveal neural function and dysfunctions concerning blood pressure control. This microneurography is applied in this project.
Publications van Schelven LJ, Karemaker JM, Blankestijn PJ, Oey PL.
Short-term sympathetic baroreflex sensitivity increases at lower blood pressures.
Clin Neurophysiol. 2008 Apr;119(4):869-79.
van Orshoven NP, van Schelven LJ, Akkermans LM, Jansen PA, Horowitz M, Feinle-Bisset C, van Huffelen AC, Oey PL.
The effect of intraduodenal glucose on muscle sympathetic nerve activity in healthy young and older subjects.
Clin Auton Res. 2008 Feb;18(1):28-35
Neumann J, Ligtenberg G, Klein IH, Boer P, Oey PL, Koomans HA, Blankestijn PJ.
Sympathetic hyperactivity in hypertensive chronic kidney disease patients is reduced during standard treatment.
Hypertension. 2007 Mar;49(3):506-10.
van Orshoven NP, Oey PL, van Schelven LJ, Roelofs JM, Jansen PA, Akkermans LM.
Effect of gastric distension on cardiovascular parameters: gastrovascular reflex is attenuated in the elderly.
J Physiol. 2004 Mar 1;555(Pt 2):573-83.]
Oey PL, Vos PE, Wieneke GH, Wokke JH, Blankestijn PJ, Karemaker JM.
Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis.
Muscle Nerve. 2002 Mar;25(3):402-8.
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