Effect of Exercise on Cerebral Circulation

Globus, Mordecai Y.‐T.; Melamed, Eldad; Keren, Andre; Tzivoni, Dan; Granot, Chaim; Lavy, S; Stern, Shlomo

doi:10.1038/jcbfm.1983.43

Cited by 37 publications

(20 citation statements)

References 14 publications

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“…However, significant local increases in flow were seen in the sensorimotor cortex and cerebellum during moder ate exercise but not during light exercise (Gross et al, 1980). In accordance with this, cortical flow, as measured by the 133Xe washout technique, in creases during moderate and heavy exercise (Her holz et al, 1987;Thomas et al, 1989), but not dur ing light dynamic exercise (Globus et al, 1983) in humans. The apparent discrepancy between the highly significant increase in TCGU in the present study and the lack of significant increases in total cerebral blood flow during exercise in dogs (Gross et al, 1980;Musch et al, 1987) Kluver-Barrera-stained histological sections (left) and autoradiographs (middle) from a resting rat and autoradiographs from a rat that ran at a speed of 28 m/min for 20 min (right).…”

Section: Discussionsupporting

confidence: 52%

Exercise-Induced Changes in Local Cerebral Glucose Utilization in the Rat

Vissing

Andersen²,

Diemer

1996

J Cereb Blood Flow Metab

145

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Summary: In exercise, little is known about local cere bral glucose utilization (LCGU), which is an index of functional neurogenic activity. We measured LCGU in resting and running (=85% of maximum O2 uptake) rats (n = 7 in both groups) previously equipped with a tail artery catheter. LCGU was measured quantitatively from 2-deoxY-D-[1-14C]glucose autoradiographs. During exer cise, total cerebral glucose utilization (TCGU) increased by 38% (p < 0.005). LCGU increased (p < 0.05) in areas involved in motor function (motor cortex 39%, cerebel lum = 110%, basal ganglia =30%, substantia nigra =37%, and in the following nuclei: subthalamic 47%, posterior hypothalamic 74%, red 61%, ambiguus 43%, pontine 61 %), areas involved in sensory function (somatosensory 27%, auditory 32%, and visual cortex 42%, thalamus =75%, and in the following nuclei: Darkschewitsch 22%, cochlear 51%, vestibular 30%, superior olive 23%, cuPronounced motor, sensory, and autonomic ad aptation is known to occur in response to both static and dynamic exercise. Such changes must be thought to evoke marked regional changes in cere bral functional activity, but little is known about the effect of exercise on regional cerebral blood flow and in particular on regional cerebral metabolism, which are both indexes of the functional activity of regional neurons (Sokoloff, 1991(Sokoloff, , 1992 729neate 115%), areas involved in autonomic function (dor sal raphe nucleus 30%, and areas in the hypothalamus =35%, amygdala =35%, and hippocampus 29%), and in white matter of the corpus callosum (36%) and cerebel lum (52%). LCGU did not change with exercise in pre frontal and frontal cortex, cingulum, inferior olive, nu cleus of solitary tract and median raphe, lateral septal and interpenduncular nuclei, or in areas of the hippocampus, amygdala, and hypothalamus. Glucose utilization did not decrease during exercise in any of the studied cerebral regions. In summary, heavy dynamic exercise increases TCGU and evokes marked differential changes in LCGU. The findings provide clues to the cerebral areas that par ticipate in the large motor, sensory, and autonomic adap tation occurring in exercise. Key Words: Autoradiogra phy-Brain glucose metabolism-2-Deoxyglucose.

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Section: Discussionsupporting

confidence: 52%

Exercise-Induced Changes in Local Cerebral Glucose Utilization in the Rat

Vissing

Andersen²,

Diemer

1996

J Cereb Blood Flow Metab

145

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“…The variables assessed to evaluate the integrity of dynamic cerebral autoregulation-the LF gain between BP and CBFV oscillations and the phase shift between BP and CBFV oscillations-demonstrated that dynamic cerebral autoregulation remained stable during increasing levels of physical exercise despite the autonomic, mechanical, and metabolic effects of increasing physical effort (7,15,24,28,32,35,41,50,53). In our study, not only did the absolute gain remain stable but we also observed no change in normalized LF gain value.…”

Section: Discussionmentioning

confidence: 46%

“…Cerebral autoregulation has to counterbalance all the cardiovascular and metabolic responses to physical effort. Although some studies suggest that CBF velocity (CBFV) and CBF remain stable despite physical effort (15), several others found an increase in CBFV (14,17,30) as well as regional CBF (10,55) and global CBF during exercise (24,51).…”

mentioning

confidence: 99%

Dynamic cerebral autoregulation remains stable during physical challenge in healthy persons

Bryś

Brown²,

Marthol³

et al. 2003

American Journal of Physiology-Heart and Circulatory Physiology

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. Dynamic cerebral autoregulation remains stable during physical challenge in healthy persons. Am J Physiol Heart Circ Physiol 285: H1048-H1054, 2003; 10.1152/ajpheart.00062.2003.-The effects of physical activity on cerebral blood flow (CBF) and cerebral autoregulation (CA) have not yet been fully evaluated. There is controversy as to whether increasing heart rate (HR), blood pressure (BP), and sympathetic and metabolic activity with altered levels of CO2 might compromise CBF and CA. To evaluate these effects, we studied middle cerebral artery blood flow velocity (CBFV) and CA in 40 healthy young adults at rest and during increasing levels of physical exercise. We continuously monitored HR, BP, endexpiratory CO 2, and CBFV with transcranial Doppler sonography at rest and during stepwise ergometric challenge at 50, 100, and 150 W. The modulation of BP and CBFV in the low-frequency (LF) range (0.04-0.14 Hz) was calculated with an autoregression algorithm. CA was evaluated by calculating the phase shift angle and gain between BP and CBFV oscillations in the LF range. The LF BP-CBFV gain was then normalized by conductance. Cerebrovascular resistance (CVR) was calculated as mean BP adjusted to brain level divided by mean CBFV. HR, BP, CO 2, and CBFV increased significantly with exercise. Phase shift angle, absolute and normalized LF BP-CBFV gain, and CVR, however, remained stable. Stable phase shift, LF BP-CBFV gain, and CVR demonstrate that progressive physical exercise does not alter CA despite increasing HR, BP, and CO 2. CA seems to compensate for the hemodynamic effects and increasing CO2 levels during exercise.cross-spectral analysis; low-frequency blood pressure-cerebral blood flow velocity gain; phase shift angle; cerebrovascular resistance CEREBRAL AUTOREGULATION normally ensures that cerebral blood flow (CBF) remains relatively constant despite fluctuations in blood pressure (BP), provided that mean BP remains within the range of autoregulation, usually from 50 to 170 mmHg (6,21,37). If BP exceeds these limits, CBF increases, initially in a curvilinear relation, and then follows BP passively in a linear relation (21, 31). During increasing levels of physical effort, cerebral perfusion is not only driven by increasing BP and heart rate (HR) but also has to adjust to high levels of sympathetic activity and to altered metabolism with changes in PO 2 and PCO 2 . With increasing muscle metabolism, PO 2 in the blood decreases, whereas PCO 2 increases, unless augmented respiration compensates for the higher O 2 demand and production of CO 2 (17,35,54). Cerebral autoregulation has to counterbalance all the cardiovascular and metabolic responses to physical effort. Although some studies suggest that CBF velocity (CBFV) and CBF remain stable despite physical effort (15), several others found an increase in CBFV (14, 17, 30) as well as regional CBF (10, 55) and global CBF during exercise (24, 51).During cardiovascular changes as they occur with increasing physical challenge, cerebral autoregulation can be evaluated b...

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“…Generally such studies involve free movement of a limb, while the subject's head remains immobilized to avoid motion artifact during brain imaging. Thus, for instance, brain activation in human subjects has been studied with SPECT during supine exercise [10,11] and cycling [12], in which the head remained immobilized inside the scanner. Likewise, PET has been applied to the brain imaging of manual tool use in monkeys, while these animals have their head and torso restrained in a chair [13], and other similar examples could be cited.…”

Section: Studies During Partial Immobilizationmentioning

confidence: 99%

Mapping brain function in freely moving subjects

Holschneider

Maarek

2004

Neuroscience & Biobehavioral Reviews

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Expression of many fundamental mammalian behaviors such as, for example, aggression, mating, foraging or social behaviors, depend on locomotor activity. A central dilemma in the functional neuroimaging of these behaviors has been the fact that conventional neuroimaging techniques generally rely on immobilization of the subject, which extinguishes all but the simplest activity. Ideally, imaging could occur in freely moving subjects, while presenting minimal interference with the subject's natural behavior. Here we provide an overview of several approaches that have been undertaken in the past to achieve this aim in both tethered and freely moving animals, as well as in nonrestrained human subjects. Applications of specific radiotracers to single photon emission computed tomography and positron emission tomography are discussed in which brain activation is imaged after completion of the behavioral task and capture of the tracer. Potential applications to clinical neuropsychiatry are discussed, as well as challenges inherent to constraint-free functional neuroimaging. Future applications of these methods promise to increase our understanding of the neural circuits underlying mammalian behavior in health and disease.

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Effect of Exercise on Cerebral Circulation

Cited by 37 publications

References 14 publications

Exercise-Induced Changes in Local Cerebral Glucose Utilization in the Rat

Exercise-Induced Changes in Local Cerebral Glucose Utilization in the Rat

Dynamic cerebral autoregulation remains stable during physical challenge in healthy persons

Mapping brain function in freely moving subjects

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