|
|
||||||||
1 Ritchie Centre for Baby Health Research, Monash Institute of Reproduction and Development, Monash University, Clayton, Victoria, 3168 Australia; and 2 Department of Human and General Physiology, University of Bologna, I-40127 Bologna, Italy
Nitric oxide (NO), being produced by active
neurones and also being a cerebral vasodilator, may couple brain
activity and blood flow in sleep, particularly during active sleep
(AS), which is characterized by widespread neural activation and
markedly elevated cerebral blood flow (CBF) compared with quiet
wakefulness (QW) and quiet sleep (QS). This study examined CBF and
cerebral vascular resistance (CVR) in lambs (n = 6)
during spontaneous sleep-wake cycles before and after infusion of
N
-nitro-L-arginine
(L-NNA), an inhibitor of NO synthase. L-NNA infusion produced increases in CVR and decreases in CBF during all
sleep-wake stages, with the greatest changes occurring in AS (
CVR,
88 ± 19%;
CBF
24 ± 8%). The characteristic CVR and CBF differences among AS, QS, and QW disappeared within 1-3 h of
L-NNA infusion, but had reappeared by 24 h despite
persisting cerebral vasoconstriction. These experiments show that NO
promotes cerebral vasodilatation during sleep as well as wakefulness,
particularly during AS. Additionally, NO is the major, although not
sole, determinant of the CBF differences that exist between sleep-wake states.
N
-nitro-L-arginine, cerebral
blood flow; cerebral vascular resistance; lamb
This article has been cited by other articles:
![]() |
G. E. Meadows, F. Kotajima, A. Vazir, K. Kostikas, A. K. Simonds, M. J. Morrell, and D. R. Corfield Overnight Changes in the Cerebral Vascular Response to Isocapnic Hypoxia and Hypercapnia in Healthy Humans: Protection Against Stroke Stroke, November 1, 2005; 36(11): 2367 - 2372. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Grant, C. Franzini, J. Wild, K. J. Eede, and A. M. Walker Autoregulation of the cerebral circulation during sleep in newborn lambs J. Physiol., May 1, 2005; 564(3): 923 - 930. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. E. Meadows, D. M. O'Driscoll, A. K. Simonds, M. J. Morrell, and D. R. Corfield Cerebral blood flow response to isocapnic hypoxia during slow-wave sleep and wakefulness J Appl Physiol, October 1, 2004; 97(4): 1343 - 1348. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. E. Meadows, H. M. A. Dunroy, M. J. Morrell, and D. R. Corfield Hypercapnic cerebral vascular reactivity is decreased, in humans, during sleep compared with wakefulness J Appl Physiol, June 1, 2003; 94(6): 2197 - 2202. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |