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Postexercise Executive Function Benefits And Cerebral Blood Flow: In The Lab And At Home, Benjamin Tari
Postexercise Executive Function Benefits And Cerebral Blood Flow: In The Lab And At Home, Benjamin Tari
Electronic Thesis and Dissertation Repository
A single bout of aerobic exercise improves executive function; however, the mechanism, or mechanisms, supporting this improvement remain unclear. One candidate mechanism is an exercise-mediated increase in cerebral blood flow (CBF) that enhances the efficiency of executive-related frontoparietal networks. To evaluate the link between exercise, CBF and executive function, three separate experiments were conducted. In the first study, separate 10-min sessions of moderate-to-heavy-intensity aerobic exercise, and a hypercapnic environment (i.e., 5% CO2) were implemented. The hypercapnic condition was included because it increases CBF independent of the metabolic demands of exercise. The second study investigated whether exercise intensity-specific changes …
Cerebrovascular Compliance In Humans, Marcy Erin Moir
Cerebrovascular Compliance In Humans, Marcy Erin Moir
Electronic Thesis and Dissertation Repository
Pulsatile blood flow consists of two components: steady flow and oscillatory flow. Steady blood flow is primarily regulated by vascular resistance while vascular compliance represents a key mediator of oscillatory blood flow. However, most studies investigating the regulation of cerebral blood flow in humans have focused on vascular resistance. Recently, emerging evidence has implicated vascular compliance as an important contributor to the regulation of cerebral perfusion. Therefore, the research contained herein aimed to i) quantify cerebrovascular compliance responses to blood pressure alterations and ii) explore mechanisms regulating cerebrovascular compliance in humans. The studies employed a Windkessel modelling approach to calculate …
Non-Invasive Quantification Of Cerebral Oxygen Metabolism By Hybrid Positron Emission Tomography/Magnetic Resonance Imaging, Lucas Diovani Lopes Narciso
Non-Invasive Quantification Of Cerebral Oxygen Metabolism By Hybrid Positron Emission Tomography/Magnetic Resonance Imaging, Lucas Diovani Lopes Narciso
Electronic Thesis and Dissertation Repository
Although positron emission tomography (PET) remains the gold standard for quantifying cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2), the procedures are invasive and complex, requiring arterial sampling and accounting for blood-borne activity. Non-invasive methods generally require extracting an image-derived input function (IDIF) from the carotid arteries; however, these methods are sensitive to partial volume errors due to the poor spatial resolution of PET. Hybrid PET/magnetic resonance imaging (MRI) offers an alternative non-invasive approach by using MRI to calibrate PET data. PET/MR imaging of oxidative metabolism (PMROx) is a reference-based approach that uses whole-brain (WB) …
Reactivity Of The Middle Cerebral Artery To Carbon Dioxide, Nicole Coverdale
Reactivity Of The Middle Cerebral Artery To Carbon Dioxide, Nicole Coverdale
Electronic Thesis and Dissertation Repository
Transcranial Doppler ultrasound (TCD) is used for the assessment of cerebral blood flow velocity (CBFV) at the middle cerebral artery (MCA) with the assumption that diameter of the artery does not change. Thus, CBFV is equivalent to cerebral blood flow (CBF). The purpose of this thesis was determine if the MCA dilates during hypercapnia (HC) and/or constricts during hypocapnia (HO) in healthy young and older adults using 3T magnetic resonance imaging (MRI). We also determined how these changes in MCA cross-sectional area (CSA) influence estimates of CBF and cerebrovascular reactivity (CVR) from TCD in young and older adults. Lastly, we …