We set out to fully examine the frequency domain relationship between arterial pressure and cerebral blood flow. Oscillatory lower body negative pressure (OLBNP) was used to create consistent blood pressure oscillations of varying frequency and amplitude to rigorously test for a frequency- and/or amplitude-dependent relationship between arterial pressure and cerebral flow. We also examined the predictions from OLBNP data for the cerebral flow response to the stepwise drop in pressure subsequent to deflation of ischaemic thigh cuffs. We measured spectral powers, cross-spectral coherence, and transfer function gains and phases in arterial pressure and cerebral flow during three amplitudes (0, 20, and 40 mmHg) and three frequencies (0.10, 0.05, and 0.03 Hz) of OLBNP in nine healthy young volunteers. Pressure fluctuations were directly related to OLBNP amplitude and inversely to OLBNP frequency. Although cerebral flow oscillations were increased, they did not demonstrate the same frequency dependence seen in pressure oscillations. The overall pattern of the pressure-flow relation was of decreasing coherence and gain and increasing phase with decreasing frequency, characteristic of a high-pass filter. Coherence between pressure and flow was increased at all frequencies by OLBNP, but was still significantly lower at frequencies below 0.07 Hz despite the augmented pressure input. In addition, predictions of thigh cuff data from spectral estimates were extremely inconsistent and highly variable, suggesting that cerebral autoregulation is a frequency-dependent mechanism that may not be fully characterized by linear methods.
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http://dx.doi.org/10.1113/jphysiol.2004.066969 | DOI Listing |
Front Oncol
January 2025
The Translational Research Institute for Neurological Disorders of Wannan Medical College, Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College (Yijishan Hospital of Wannan Medical College), Wuhu, Anhui, China.
Introduction: Gliomas, particularly glioblastomas (GBM), are highly aggressive with a poor prognosis and low survival rate. Currently, deoxyelephantopin (DET) has shown promising anti-inflammatory and anti-tumor effects. Using clinical prognostic analysis, molecular docking, and network pharmacology, this study aims to explore the primary targets and signaling pathways to identify novel GBM treatment approaches.
View Article and Find Full Text PDFFront Aging Neurosci
January 2025
Department of Neurology, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, China.
Introduction: Cerebral small vessel disease (CSVD) is a chronic systemic degenerative disease affecting small blood vessels in the brain, leading to cognitive impairments. Transcranial direct current stimulation (tDCS), a non-invasive brain stimulation technique that applies low electrical currents to the scalp, shows promise in treating cognitive and movement disorders. However, further clinical evaluation is required to assess the long-term effects of tDCS on neuroplasticity and gait in patients with CSVD.
View Article and Find Full Text PDFClin Kidney J
January 2025
Department of Nephrology, Beijing Friendship Hospital, Capital Medical University, Xicheng District, Beijing, China.
Background: Neurovascular coupling (NVC), as indicated by a comprehensive analysis of the amplitude of low-frequency fluctuation (ALFF) and cerebral blood flow (CBF), provides mechanistic insights into neurological disorders. Patients undergoing peritoneal dialysis (PD) and hemodialysis (HD) often face cognitive impairment, the causes of which are not fully understood.
Methods: ALFF was derived from functional magnetic resonance imaging, and CBF was quantified using arterial spin labeling in a cohort comprising 58 patients with PD, 60 patients with HD and 62 healthy controls.
Emerg Med Int
January 2025
Nanjing Comprehensive Stroke Center, Affiliated Nanjing Brain Hospital of Nanjing Medical University, Nanjing, China.
Ischemic stroke is one of the major emergency diseases leading to death and disability worldwide, characterized by its acute onset and the urgent need for prompt medical intervention to reduce mortality and long-term disability. Chronic terminal internal carotid artery and/or middle cerebral artery occlusion (CTI/MCAO) is an important subtype of intracranial artery occlusive disease. The superficial temporal artery-to-MCA (STA-MCA) bypass has been proposed to improve cerebral blood flow (CBF) and cerebrovascular reserve (CVR), potentially enhancing neurological outcomes.
View Article and Find Full Text PDFBioact Mater
April 2025
Beijing Key Laboratory for Biomaterials and Neural Regeneration, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing 100083, China.
The mammalian brain has an extremely limited ability to regenerate lost neurons and to recover function following ischemic stroke. A biomaterial strategy of slowly-releasing various regeneration-promoting factors to activate endogenous neurogenesis represents a safe and practical neuronal replacement therapy. In this study, basic fibroblast growth factor (bFGF)-Chitosan gel is injected into the stroke cavity.
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