1
|
Kostoglou K, Bello-Robles F, Brassard P, Chacon M, Claassen JA, Czosnyka M, Elting JW, Hu K, Labrecque L, Liu J, Marmarelis VZ, Payne SJ, Shin DC, Simpson D, Smirl J, Panerai RB, Mitsis GD. Time-domain methods for quantifying dynamic cerebral blood flow autoregulation: Review and recommendations. A white paper from the Cerebrovascular Research Network (CARNet). J Cereb Blood Flow Metab 2024; 44:1480-1514. [PMID: 38688529 DOI: 10.1177/0271678x241249276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Cerebral Autoregulation (CA) is an important physiological mechanism stabilizing cerebral blood flow (CBF) in response to changes in cerebral perfusion pressure (CPP). By maintaining an adequate, relatively constant supply of blood flow, CA plays a critical role in brain function. Quantifying CA under different physiological and pathological states is crucial for understanding its implications. This knowledge may serve as a foundation for informed clinical decision-making, particularly in cases where CA may become impaired. The quantification of CA functionality typically involves constructing models that capture the relationship between CPP (or arterial blood pressure) and experimental measures of CBF. Besides describing normal CA function, these models provide a means to detect possible deviations from the latter. In this context, a recent white paper from the Cerebrovascular Research Network focused on Transfer Function Analysis (TFA), which obtains frequency domain estimates of dynamic CA. In the present paper, we consider the use of time-domain techniques as an alternative approach. Due to their increased flexibility, time-domain methods enable the mitigation of measurement/physiological noise and the incorporation of nonlinearities and time variations in CA dynamics. Here, we provide practical recommendations and guidelines to support researchers and clinicians in effectively utilizing these techniques to study CA.
Collapse
Affiliation(s)
- Kyriaki Kostoglou
- Department of Electrical and Computer Engineering, McGill University, Montreal, QC, Canada
- Institute of Neural Engineering, Graz University of Technology, Graz, Austria
| | - Felipe Bello-Robles
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile
| | - Patrice Brassard
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec, QC, Canada
- Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, QC, Canada
| | - Max Chacon
- Departamento de Ingeniería Informática, Universidad de Santiago de Chile, Santiago, Chile
| | - Jurgen Ahr Claassen
- Department of Geriatrics, Radboud University Medical Center, Research Institute for Medical Innovation and Donders Institute, Nijmegen, The Netherlands
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM), Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
| | - Marek Czosnyka
- Department of Clinical Neurosciences, Neurosurgery Department, University of Cambridge, Cambridge, UK
| | - Jan-Willem Elting
- Department of Neurology and Clinical Neurophysiology, University Medical Center Groningen, Groningen, The Netherlands
| | - Kun Hu
- Medical Biodynamics Program, Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA, USA
| | - Lawrence Labrecque
- Department of Kinesiology, Faculty of Medicine, Université Laval, Quebec, QC, Canada
- Research Center of the Institut universitaire de cardiologie et de pneumologie de Québec, Quebec, QC, Canada
| | - Jia Liu
- Laboratory for Engineering and Scientific Computing, Institute of Advanced Computing and Digital Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, China
| | - Vasilis Z Marmarelis
- Department Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - Stephen J Payne
- Institute of Applied Mechanics, National Taiwan University, Taipei, Taiwan
| | - Dae Cheol Shin
- Department Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA
| | - David Simpson
- Institute of Sound and Vibration Research, University of Southampton, Southampton, UK
| | - Jonathan Smirl
- Cerebrovascular Concussion Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Sport Injury Prevention Research Centre, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ronney B Panerai
- Cerebral Haemodynamics in Ageing and Stroke Medicine (CHiASM), Department of Cardiovascular Sciences, University of Leicester, Leicester, UK
- NIHR Leicester Biomedical Research Centre, British Heart Foundation, Glenfield Hospital, Leicester, UK
| | - Georgios D Mitsis
- Department of Bioengineering, McGill University, Montreal, QC, Canada
| |
Collapse
|
2
|
Bokov P, Koehl B, Benzouid C, Verlhac S, Missud F, Benkerrou M, Delclaux C. No Increase in Masked Hypertension Prevalence in Children With Sickle Cell Disease in France. Am J Hypertens 2024; 37:358-365. [PMID: 38323455 DOI: 10.1093/ajh/hpae013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/11/2024] [Accepted: 01/26/2024] [Indexed: 02/08/2024] Open
Abstract
BACKGROUND An important prevalence (32%-45%) of masked hypertension has been reported in children with sickle cell disease (SCD). Stroke screening is well established using transcranial Doppler (TCD) ultrasound. The objectives of our proof-of-concept study in childhood SCD were to evaluate the prevalence of hypertension and its relationships with cerebral vasculopathy (TCD velocity) and to further evaluate in a subgroup of children the correlations of cardiovascular autonomic nervous system indices with TCD velocity. METHODS Ambulatory blood pressure measurement (ABPM) and TCD velocity were obtained in children with SCD and in a restricted sample, cardiac sympathovagal balance using heart rate variability analyses, baroreflex sensitivity, and pulse wave velocity were measured. RESULTS In 41 children with SCD (median age 14.0 years, 19 girls, SS/Sβ + thalassemia/SC: 33/2/6), ABPM results showed masked hypertension in 2/41 (5%, 95% confidence interval, 0-11) children, consistent with the prevalence in the general pediatric population, elevated blood pressure (BP) in 4/41 (10%) children, and a lack of a normal nocturnal dip in 19/41 children (46%). Children with increased TCD velocity had lower nocturnal dipping of systolic BP. In the 10 participants with extensive cardiovascular assessment, increased TCD velocity was associated with parasympathetic withdrawal and baroreflex failure. Exaggerated orthostatic pressor response or orthostatic hypertension was observed in 7/10 children that was linked to parasympathetic withdrawal. CONCLUSIONS Autonomic nervous system dysfunction, namely loss of parasympathetic modulation, of SCD contributes to increase TCD velocity but is not associated with an increased prevalence of masked hypertension. CLINICAL TRIALS REGISTRATION NCT04911049.
Collapse
Affiliation(s)
- Plamen Bokov
- Paris University, AP-HP, Robert Debré Hospital, Department of Physiology, INSERM NeuroDiderot, Paris, France
| | - Berengere Koehl
- Department of Hematology, Paris University, AP-HP, Robert Debré Hospital, Sickle Cell Disease Center, Hematology Unit, Paris, France
- UMR_S1134, BIGR, INSERM, Institut National de la Transfusion Sanguine, Laboratoire d'Excellence GR-Ex, Paris, France
| | - Chérine Benzouid
- Department of Physiology, AP-HP, Robert Debré Hospital, Paris, France
| | - Suzanne Verlhac
- Department of Pediatric Imaging, AP-HP, Robert Debré Hospital, Paris, France
| | - Florence Missud
- Sickle Cell Disease Center, Hematology Unit, Robert Debré Hospital, AP-HP, Paris, France
- INSERM UMR 1123, ECEVE, Paris, France
| | - Malika Benkerrou
- Sickle Cell Disease Center, Hematology Unit, Robert Debré Hospital, AP-HP, Paris, France
- INSERM UMR 1123, ECEVE, Paris, France
| | - Christophe Delclaux
- Paris University, AP-HP, Robert Debré Hospital, Department of Physiology, INSERM NeuroDiderot, Paris, France
| |
Collapse
|
3
|
Lakatos LB, Shin DC, Müller M, Österreich M, Marmarelis V, Bolognese M. Impaired dynamic cerebral autoregulation measured in the middle cerebral artery in patients with vertebrobasilar ischemia is associated with autonomic failure. J Stroke Cerebrovasc Dis 2024; 33:107454. [PMID: 37931481 PMCID: PMC10841591 DOI: 10.1016/j.jstrokecerebrovasdis.2023.107454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 10/21/2023] [Accepted: 10/26/2023] [Indexed: 11/08/2023] Open
Abstract
OBJECTIVES To assess whether vertebrobasilar artery ischemia (VBI) affects cortical cerebral blood flow (CBF) regulation. MATERIAL AND METHODS 107 consecutive patients (mean age 65 ± 15 years; women 21) with VBI underwent structured stroke care with assessment of dynamic cerebral autoregulation (dCA) in both middle cerebral arteries (MCAs) by transfer function analysis using spontaneous oscillations of blood pressure (BP) and CBF velocity that yields by extraction of phase and gain information in the very low (0.02-0.07 Hz), low (0.07-0.15 Hz) and high frequency (0.15-0.5 Hz) ranges. Additionally, power spectrum analysis of BP and heart rate variability (HRV) was performed. The control group consists of 29 age- and sex-matched healthy persons. RESULTS Compared to controls, phase in the VBI patients was significantly reduced and gain increased in the very low frequencies (VLF), in the low (LF), phase was significantly reduced only ipsilaterally. In the high frequencies (HF), phase reduction was only marginally significant. BP power spectral density (PSD) was much higher in the patients than in the controls across all frequencies. In the PSD of heart rate variability the controls but not the patients exhibited a strong peak around 0.11Hz, while the patients, but not the controls, exhibit a strong peak around 0.36 Hz. In regression analysis, patient's phase and gain results were not related to age, sex, arterial hypertension, diabetes mellitus, renal dysfunction, heart failure as indicated by left ventricular ejection fraction, stroke subtype, presence or absence of cerebral small vessel disease. CONCLUSION Patients with VBI exhibit bilateral cortical autoregulation impairment in association with an autonomic nervous system disbalance. CLINICALTRIALS GOV IDENTIFIER NCT04611672.
Collapse
Affiliation(s)
- Lehel Barna Lakatos
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| | - Dae C Shin
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States
| | - Martin Müller
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland.
| | - Mareike Österreich
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| | - Vasilis Marmarelis
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, United States
| | - Manuel Bolognese
- Department of Neurology and Neurorehabilitation, Lucerne Kantonsspital, Spitalstrasse Switzerland
| |
Collapse
|
4
|
Marmarelis VZ, Shin DC, Hamner JW, Tan CO. Dynamic effects of cholinergic blockade upon cerebral blood flow autoregulation in healthy adults. Front Physiol 2022; 13:1015544. [PMID: 36406984 PMCID: PMC9666788 DOI: 10.3389/fphys.2022.1015544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Accepted: 10/05/2022] [Indexed: 01/25/2023] Open
Abstract
Background: Cerebral flow autoregulation (CFA) is a homeostatic mechanism critical for survival. The autonomic nervous system (ANS) plays a key role in maintaining proper CFA function. More quantitative studies of how the ANS influences CFA are desirable. Objective: To discover and quantify the dynamic effects of cholinergic blockade upon CFA in response to changes of arterial blood pressure and blood CO2 tension in healthy adults. Methods: We analyzed time-series data of spontaneous beat-to-beat mean arterial blood pressure (ABP) and cerebral blood flow velocity in the middle cerebral arteries (CFV), as well as breath-to-breath end-tidal CO2 (CO2), collected in 9 adults before and after cholinergic blockade, in order to obtain subject-specific predictive input-output models of the dynamic effects of changes in ABP and CO2 (inputs) upon CFV (output). These models are defined in convolutional form using "kernel" functions (or, equivalently, Transfer Functions in the frequency domain) that are estimated via the robust method of Laguerre expansions. Results: Cholinergic blockade caused statistically significant changes in the obtained kernel estimates (and the corresponding Transfer Functions) that define the linear dynamics of the ABP-to-CFV and CO2-to-CFV causal relations. The kernel changes due to cholinergic blockade reflect the effects of the cholinergic mechanism and exhibited, in the frequency domain, resonant peaks at 0.22 Hz and 0.06 Hz for the ABP-to-CFV and CO2-to-CFV dynamics, respectively. Conclusion: Quantitative estimates of the dynamics of the cholinergic component in CFA are found as average changes of the ABP-to-CFV and CO2-to-CFV kernels, and corresponding Transfer Functions, before and after cholinergic blockade.
Collapse
Affiliation(s)
- Vasilis Z. Marmarelis
- Biomedical Engineering, University of Southern CA, Los Angeles, MA, United States,*Correspondence: Vasilis Z. Marmarelis,
| | - Dae C. Shin
- Biomedical Engineering, University of Southern CA, Los Angeles, MA, United States
| | - Jason W. Hamner
- Cardiovascular Research Laboratory, Spaulding Rehabilitation Hospital, Boston, MA, United States
| | - Can Ozan Tan
- Electrical Engineering Math and Computer Science, University of Twente, Enschede, Netherlands
| |
Collapse
|
5
|
Scholkmann F, Tachtsidis I, Wolf M, Wolf U. Systemic physiology augmented functional near-infrared spectroscopy: a powerful approach to study the embodied human brain. NEUROPHOTONICS 2022; 9:030801. [PMID: 35832785 PMCID: PMC9272976 DOI: 10.1117/1.nph.9.3.030801] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 06/07/2022] [Indexed: 05/15/2023]
Abstract
In this Outlook paper, we explain why an accurate physiological interpretation of functional near-infrared spectroscopy (fNIRS) neuroimaging signals is facilitated when systemic physiological activity (e.g., cardiorespiratory and autonomic activity) is measured simultaneously by employing systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS). The rationale for SPA-fNIRS is twofold: (i) SPA-fNIRS enables a more complete interpretation and understanding of the fNIRS signals measured at the head since they contain components originating from neurovascular coupling and from systemic physiological sources. The systemic physiology signals measured with SPA-fNIRS can be used for regressing out physiological confounding components in fNIRS signals. Misinterpretations can thus be minimized. (ii) SPA-fNIRS enables to study the embodied brain by linking the brain with the physiological state of the entire body, allowing novel insights into their complex interplay. We envisage the SPA-fNIRS approach will become increasingly important in the future.
Collapse
Affiliation(s)
- Felix Scholkmann
- University of Bern, Institute of Complementary and Integrative Medicine, Bern, Switzerland
- University Hospital Zurich, University of Zurich, Biomedical Optics Research Laboratory, Neonatology Research, Department of Neonatology, Zurich, Switzerland
| | - Ilias Tachtsidis
- University College London, Biomedical Optics Research Laboratory, Department of Medical Physics and Biomedical Engineering, London, United Kingdom
| | - Martin Wolf
- University Hospital Zurich, University of Zurich, Biomedical Optics Research Laboratory, Neonatology Research, Department of Neonatology, Zurich, Switzerland
| | - Ursula Wolf
- University of Bern, Institute of Complementary and Integrative Medicine, Bern, Switzerland
| |
Collapse
|
6
|
Llwyd O, Fan JL, Müller M. Effect of drug interventions on cerebral hemodynamics in ischemic stroke patients. J Cereb Blood Flow Metab 2022; 42:471-485. [PMID: 34738511 PMCID: PMC8985436 DOI: 10.1177/0271678x211058261] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The ischemic penumbra is sensitive to alterations in cerebral perfusion. A myriad of drugs are used in acute ischemic stroke (AIS) management, yet their impact on cerebral hemodynamics is poorly understood. As part of the Cerebral Autoregulation Network led INFOMATAS project (Identifying New Targets for Management and Therapy in Acute Stroke), this paper reviews some of the most common drugs a patient with AIS will come across and their potential influence on cerebral hemodynamics with a particular focus being on cerebral autoregulation (CA). We first discuss how compounds that promote clot lysis and prevent clot formation could potentially impact cerebral hemodynamics, before focusing on how the different classes of antihypertensive drugs can influence cerebral hemodynamics. We discuss the different properties of each drug and their potential impact on cerebral perfusion and CA. With emerging interest in CA status of AIS patients, either during or soon after treatment when timely reperfusion and salvageable tissue is at its most critical, the properties of these pharmacological agents may be relevant for modelling cerebral perfusion accuracy and for setting individualised treatment strategies.
Collapse
Affiliation(s)
- Osian Llwyd
- Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine Research Group, University of Leicester, Leicester, UK
| | - Jui-Lin Fan
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
| | - Martin Müller
- Neurozentrum, Klinik für Neurologie und Neurorehabilitation, Luzerner Kantonsspital, Spitalstrasse, Luzern, Switzerland
| |
Collapse
|
7
|
Marmarelis VZ, Shin DC, Zhang R. The Dynamic Relationship Between Cortical Oxygenation and End-Tidal CO 2 Transient Changes Is Impaired in Mild Cognitive Impairment Patients. Front Physiol 2021; 12:772456. [PMID: 34955886 PMCID: PMC8695976 DOI: 10.3389/fphys.2021.772456] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 11/19/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Recent studies have utilized data-based dynamic modeling to establish strong association between dysregulation of cerebral perfusion and Mild Cognitive Impairment (MCI), expressed in terms of impaired CO2 dynamic vasomotor reactivity in the cerebral vasculature. This raises the question of whether this is due to dysregulation of central mechanisms (baroreflex and chemoreflex) or mechanisms of cortical tissue oxygenation (CTO) in MCI patients. We seek to answer this question using data-based input-output predictive dynamic models. Objective: To use subject-specific data-based multivariate input-output dynamic models to quantify the effects of systemic hemodynamic and blood CO2 changes upon CTO and to examine possible differences in CTO regulation in MCI patients versus age-matched controls, after the dynamic effects of central regulatory mechanisms have been accounted for by using cerebral flow measurements as another input. Methods: The employed model-based approach utilized the general dynamic modeling methodology of Laguerre expansions of kernels to analyze spontaneous time-series data in order to quantify the dynamic effects upon CTO (an index of relative capillary hemoglobin saturation distribution measured via near-infrared spectroscopy) of contemporaneous changes in end-tidal CO2 (proxy for arterial CO2), arterial blood pressure and cerebral blood flow velocity in the middle cerebral arteries (measured via transcranial Doppler). Model-based indices (physio-markers) were computed for these distinct dynamic relationships. Results: The obtained model-based indices revealed significant statistical differences of CO2 dynamic vasomotor reactivity in cortical tissue, combined with "perfusivity" that quantifies the dynamic relationship between flow velocity in cerebral arteries and CTO in MCI patients versus age-matched controls (p = 0.006). Significant difference between MCI patients and age-matched controls was also found in the respective model-prediction accuracy (p = 0.0001). Combination of these model-based indices via the Fisher Discriminant achieved even smaller p-value (p = 5 × 10-5) when comparing MCI patients with controls. The differences in dynamics of CTO in MCI patients are in lower frequencies (<0.05 Hz), suggesting impairment in endocrine/metabolic (rather than neural) mechanisms. Conclusion: The presented model-based approach elucidates the multivariate dynamic connectivity in the regulation of cerebral perfusion and yields model-based indices that may serve as physio-markers of possible dysregulation of CTO during transient CO2 changes in MCI patients.
Collapse
Affiliation(s)
- Vasilis Z. Marmarelis
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA, United States
| | - Dae C. Shin
- Biomedical Engineering Department, University of Southern California, Los Angeles, CA, United States
| | - Rong Zhang
- Institute for Exercise and Environmental Medicine, UT Southwestern Medical Center, Dallas, TX, United States
| |
Collapse
|
8
|
Abstract
PURPOSE OF REVIEW Rapidly emerging evidence implicates an important role of gut-brain-bone marrow (BM) axis involving gut microbiota (GM), gut epithelial wall permeability, increased production of pro-inflammatory BM cells and neuroinflammation in hypertension (HTN). However, the precise sequence of events involving these organs remains to be established. Furthermore, whether an impaired gut-brain-BM axis is a cause or consequence of HTN is actively under investigation. This will be extremely important for translation of this fundamental knowledge to novel, innovative approaches for the control and management of HTN. Therefore, our objectives are to summarize the latest hypothesis, provide evidence for and against the impaired gut, BM and brain interactions in HTN and discuss perspectives and future directions. RECENT FINDINGS Hypertensive stimuli activate autonomic neural pathways resulting in increased sympathetic and decreased parasympathetic cardiovascular modulation. This directly affects the functions of cardiovascular-relevant organs to increase blood pressure. Increases in sympathetic drive to the gut and BM also trigger sequences of signaling events that ultimately contribute to altered GM, increased gut permeability, enhanced gut- and brain-targeted pro-inflammatory cells from the BM in perpetuation and establishment of HTN. SUMMARY In this review, we present the mechanisms involving the brain, gut, and BM, whose dysfunctional interactions may be critical in persistent neuroinflammation and key in the development and establishment of HTN.
Collapse
Affiliation(s)
- Jing Li
- Department of Physiology and Functional Genomics, University of Florida College of Medicine, Gainesville, FL, USA
| | | | | |
Collapse
|
9
|
Presa JL, Saravia F, Bagi Z, Filosa JA. Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension. Front Physiol 2020; 11:584135. [PMID: 33101063 PMCID: PMC7546852 DOI: 10.3389/fphys.2020.584135] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 12/18/2022] Open
Abstract
Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.
Collapse
Affiliation(s)
- Jessica L Presa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Flavia Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Zsolt Bagi
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jessica A Filosa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| |
Collapse
|