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Resting fluctuations in arterial carbon dioxide induce significant low frequency variations in BOLD signal
We have identified a significant source of low-frequency variation in blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) signal arising from spontaneous fluctuations in arterial carbon dioxide level in volunteers at rest. Expand
Relationship between middle cerebral artery blood velocity and end-tidal PCO2 in the hypocapnic-hypercapnic range in humans.
This study examined the relationship between cerebral blood flow (CBF) and end-tidal PCO2 (PETCO2) in humans. We used transcranial Doppler ultrasound to determine middle cerebral artery peak bloodExpand
Cerebral blood flow and metabolism during exercise
During exercise regional cerebral blood flow (rCBF), as blood velocity in major cerebral arteries and also blood flow in the internal carotid artery increase, suggesting an increase in blood flow toExpand
Cerebral metabolic response to submaximal exercise.
We studied cerebral oxygenation and metabolism during submaximal cycling in 12 subjects. At two work rates, middle cerebral artery blood velocity increased from 62 +/- 3 to 63 +/- 3 and 70 +/- 5 cm/sExpand
Lactate, glucose and O2 uptake in human brain during recovery from maximal exercise
The metabolic activity of the brain has not been evaluated during physical exercise. In six volunteers substrate uptake by the brain was determined during graded exercise and recovery from maximalExpand
The intent to exercise influences the cerebral O2/carbohydrate uptake ratio in humans
During and after maximal exercise there is a 15–30 % decrease in the metabolic uptake ratio (O2/[glucose +1/2lactate]) and a net lactate uptake by the human brain. This study evaluated if thisExpand
Differential responses to CO2 and sympathetic stimulation in the cerebral and femoral circulations in humans
The relative importance of CO2 and sympathetic stimulation in the regulation of cerebral and peripheral vasculatures has not been previously studied in humans. We investigated the effect ofExpand
Effects of partial neuromuscular blockade on carotid baroreflex function during exercise in humans
1 This investigation was designed to determine the contribution of central command to the resetting of the carotid baroreflex during static and dynamic exercise in humans. 2 Thirteen subjectsExpand
Middle cerebral artery blood velocity during exercise with beta-1 adrenergic and unilateral stellate ganglion blockade in humans.
A reduced ability to increase cardiac output (CO) during exercise limits blood flow by vasoconstriction even in active skeletal muscle. Such a flow limitation may also take place in the brain as anExpand
Middle cerebral artery blood velocity during a valsalva maneuver in the standing position.
Occasionally, lifting of a heavy weight leads to dizziness and even to fainting, suggesting that, especially in the standing position, expiratory straining compromises cerebral perfusion. In 10Expand