Autonomic neural control of cerebral hemodynamics.
Despite the rich innervation of the cerebral vasculature by both sympathetic and parasympathetic nerves, the role of autonomic control in cerebral circulation and, particularly, cerebral hemodynamics is not entirely clear. Previous animal studies have reported inconsistent results regarding the effects of electrical stimulation or denervation on cerebral blood flow (CBF), cerebral pressure-flow relationship, and cerebral vessel response to metabolic stimuli. Moreover, with the advance of transcranial Doppler ultrasound (TCD), which yields accurate measurements of CBF velocity (CBFV) with high time resolution, it has been found that in humans CBFV in the middle cerebral artery decreased substantially during lower body negative pressure (LBNP) and head-up tilt in the absence of systemic hypotension, which suggests the presence of cerebral vasoconstriction associated with augmented sympathetic nerve activity during orthostatic stress. These observations were based on assessing static measures of cerebral circulation, i.e., mean values of artevial blood pressure (ABP) and CBF with a low time resolution.
Mitsis
Georgios D
GD
Department of Electrical and Computer Engineering, PO Box 20537, Kallipoleos 75, Nicosia 1678 Cyprus. gmitsis@ucy.ac.cy
Zhang
Rong
R
Levine
Benjamin D
BD
Tzanalaridou
Efthalia
E
Katritsis
Demosthenes G
DG
Marmarelis
Vasilis Z
VZ
D000328:Adult; D001340:Autonomic Nerve Block; D001341:Autonomic Nervous System / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D002245:Carbon Dioxide / Q000378:metabolism; D002536:Cerebral Arteries / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D015999:Multivariate Analysis; D017711:Nonlinear Dynamics; D017585:Ultrasonography, Doppler, Transcranial
D002245:Carbon Dioxide