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Bah TM, Davis CM, Allen EM, Borkar RN, Perez R, Grafe MR, Raber J, Pike MM, Alkayed NJ. Soluble epoxide hydrolase inhibition reverses cognitive dysfunction in a mouse model of metabolic syndrome by modulating inflammation. Prostaglandins Other Lipid Mediat 2024; 173:106850. [PMID: 38735559 PMCID: PMC11218661 DOI: 10.1016/j.prostaglandins.2024.106850] [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: 03/01/2024] [Revised: 04/26/2024] [Accepted: 05/07/2024] [Indexed: 05/14/2024]
Abstract
Midlife metabolic syndrome (MetS) is associated with cognitive impairment in late life. The mechanism of delayed MetS-related cognitive dysfunction (MetSCD) is not clear, but it has been linked to systemic inflammation and chronic cerebral microangiopathy. Currently there is no treatment for late life MetSCD other than early risk factor modification. We investigated the effect of soluble epoxide hydrolase (sEH) inhibitor 4-[[trans-4-[[(tricyclo[3.3.1.13,7]dec-1-ylamino)carbonyl]amino]cyclohexyl]oxy]-benzoic acid (t-AUCB) on cognitive performance, cerebral blood flow (CBF), and central and peripheral inflammation in the high-fat diet (HFD) model of MetS in mice. At 6 weeks of age, male mice were randomly assigned to receive either HFD or standard chow (STD) for 6 months. Mice received either t-AUCB or vehicle for 4 weeks. Cognitive performance was evaluated, followed by CBF measurement using magnetic resonance imaging (MRI). At the end of the study, blood was collected for measurement of eicosanoids and inflammatory cytokines. The brains were then analyzed by immunohistochemistry for glial activation markers. The HFD caused a significant impairment in novel object recognition. Treatment with t-AUCB increased plasma levels of 14,15-EET, prevented this cognitive impairment and modified hippocampal glial activation and plasma cytokine levels, without affecting CBF in mice on HFD. In conclusion, sEH inhibition for four weeks prevents cognitive deficits in mice on chronic HFD by modulating inflammatory processes without affecting CBF.
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Affiliation(s)
- Thierno M Bah
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Catherine M Davis
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Elyse M Allen
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Rohan N Borkar
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - Ruby Perez
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA
| | - Marjorie R Grafe
- Department of Pathology, Oregon Health & Science University, Portland, OR, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, USA; Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR, USA
| | - Martin M Pike
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, USA
| | - Nabil J Alkayed
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA; Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA.
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2
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Mester JR, Rozak MW, Dorr A, Goubran M, Sled JG, Stefanovic B. Network response of brain microvasculature to neuronal stimulation. Neuroimage 2024; 287:120512. [PMID: 38199427 DOI: 10.1016/j.neuroimage.2024.120512] [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: 09/08/2023] [Revised: 12/21/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024] Open
Abstract
Neurovascular coupling (NVC), or the adjustment of blood flow in response to local increases in neuronal activity is a hallmark of healthy brain function, and the physiological foundation for functional magnetic resonance imaging (fMRI). However, it remains only partly understood due to the high complexity of the structure and function of the cerebrovascular network. Here we set out to understand NVC at the network level, i.e. map cerebrovascular network reactivity to activation of neighbouring neurons within a 500×500×500 μm3 cortical volume (∼30 high-resolution 3-nL fMRI voxels). Using 3D two-photon fluorescence microscopy data, we quantified blood volume and flow changes in the brain vessels in response to spatially targeted optogenetic activation of cortical pyramidal neurons. We registered the vessels in a series of image stacks acquired before and after stimulations and applied a deep learning pipeline to segment the microvascular network from each time frame acquired. We then performed image analysis to extract the microvascular graphs, and graph analysis to identify the branch order of each vessel in the network, enabling the stratification of vessels by their branch order, designating branches 1-3 as precapillary arterioles and branches 4+ as capillaries. Forty-five percent of all vessels showed significant calibre changes; with 85 % of responses being dilations. The largest absolute CBV change was in the capillaries; the smallest, in the venules. Capillary CBV change was also the largest fraction of the total CBV change, but normalized to the baseline volume, arterioles and precapillary arterioles showed the biggest relative CBV change. From linescans along arteriole-venule microvascular paths, we measured red blood cell velocities and hematocrit, allowing for estimation of pressure and local resistance along these paths. While diameter changes following neuronal activation gradually declined along the paths; the pressure drops from arterioles to venules increased despite decreasing resistance: blood flow thus increased more than local resistance decreases would predict. By leveraging functional volumetric imaging and high throughput deep learning-based analysis, our study revealed distinct hemodynamic responses across the vessel types comprising the microvascular network. Our findings underscore the need for large, dense sampling of brain vessels for characterization of neurovascular coupling at the network level in health and disease.
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Affiliation(s)
- James R Mester
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Matthew W Rozak
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Adrienne Dorr
- Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Maged Goubran
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - John G Sled
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Mouse Imaging Centre, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Bojana Stefanovic
- University of Toronto, Department of Medical Biophysics, Toronto, Ontario, Canada; Physical Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada.
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3
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You TY, Dong Q, Cui M. Emerging Links between Cerebral Blood Flow Regulation and Cognitive Decline: A Role for Brain Microvascular Pericytes. Aging Dis 2023:AD.2022.1204. [PMID: 37163446 PMCID: PMC10389833 DOI: 10.14336/ad.2022.1204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Accepted: 12/04/2022] [Indexed: 05/12/2023] Open
Abstract
Cognitive impairment associated with vascular etiology has been of considerable interest in the development of dementia. Recent studies have started to uncover cerebral blood flow deficits in initiating cognitive deterioration. Brain microvascular pericytes, the only type of contractile cells in capillaries, are involved in the precise modulation of vascular hemodynamics due to their ability to regulate resistance in the capillaries. They exhibit potential in maintaining the capillary network geometry and basal vascular tone. In addition, pericytes can facilitate better blood flow supply in response to neurovascular coupling. Their dysfunction is thought to disturb cerebral blood flow causing metabolic imbalances or structural injuries, leading to consequent cognitive decline. In this review, we summarize the characteristics of microvascular pericytes in brain blood flow regulation and outline the framework of a two-hit hypothesis in cognitive decline, where we emphasize how pericytes serve as targets of cerebral blood flow dysregulation that occurs with neurological challenges, ranging from genetic factors, aging, and pathological proteins to ischemic stress.
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Affiliation(s)
- Tong-Yao You
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Qiang Dong
- Department of Neurology, Huashan Hospital, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
- National Center for Neurological Disorders, Huashan Hospital, Fudan University, Shanghai, China
| | - Mei Cui
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
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4
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Alarcon-Martinez L, Shiga Y, Villafranca-Baughman D, Cueva Vargas JL, Vidal Paredes IA, Quintero H, Fortune B, Danesh-Meyer H, Di Polo A. Neurovascular dysfunction in glaucoma. Prog Retin Eye Res 2023; 97:101217. [PMID: 37778617 DOI: 10.1016/j.preteyeres.2023.101217] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/23/2023] [Accepted: 09/25/2023] [Indexed: 10/03/2023]
Abstract
Retinal ganglion cells, the neurons that die in glaucoma, are endowed with a high metabolism requiring optimal provision of oxygen and nutrients to sustain their activity. The timely regulation of blood flow is, therefore, essential to supply firing neurons in active areas with the oxygen and glucose they need for energy. Many glaucoma patients suffer from vascular deficits including reduced blood flow, impaired autoregulation, neurovascular coupling dysfunction, and blood-retina/brain-barrier breakdown. These processes are tightly regulated by a community of cells known as the neurovascular unit comprising neurons, endothelial cells, pericytes, Müller cells, astrocytes, and microglia. In this review, the neurovascular unit takes center stage as we examine the ability of its members to regulate neurovascular interactions and how their function might be altered during glaucomatous stress. Pericytes receive special attention based on recent data demonstrating their key role in the regulation of neurovascular coupling in physiological and pathological conditions. Of particular interest is the discovery and characterization of tunneling nanotubes, thin actin-based conduits that connect distal pericytes, which play essential roles in the complex spatial and temporal distribution of blood within the retinal capillary network. We discuss cellular and molecular mechanisms of neurovascular interactions and their pathophysiological implications, while highlighting opportunities to develop strategies for vascular protection and regeneration to improve functional outcomes in glaucoma.
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Affiliation(s)
- Luis Alarcon-Martinez
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada; Centre for Eye Research Australia, University of Melbourne, Melbourne, Australia
| | - Yukihiro Shiga
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Deborah Villafranca-Baughman
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Jorge L Cueva Vargas
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Isaac A Vidal Paredes
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Heberto Quintero
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada
| | - Brad Fortune
- Discoveries in Sight Research Laboratories, Devers Eye Institute and Legacy Research Institute, Legacy Healthy, Portland, OR, USA
| | - Helen Danesh-Meyer
- Department of Ophthalmology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, University of Auckland, New Zealand
| | - Adriana Di Polo
- Department of Neuroscience, Université de Montréal, PO Box 6128, Station centre-ville, Montreal, QC, Canada; Neuroscience Division, Centre de recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), 900 Saint Denis Street, Montreal, QC, Canada.
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5
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Xu Y, Zhang WH, Allen EM, Fedorov LM, Barnes AP, Qian ZY, Bah TM, Li Y, Wang RK, Shangraw RE, Alkayed NJ. GPR39 Knockout Worsens Microcirculatory Response to Experimental Stroke in a Sex-Dependent Manner. Transl Stroke Res 2023; 14:766-775. [PMID: 36181628 PMCID: PMC10065946 DOI: 10.1007/s12975-022-01093-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/02/2022] [Accepted: 09/26/2022] [Indexed: 10/07/2022]
Abstract
No current treatments target microvascular reperfusion after stroke, which can contribute to poor outcomes even after successful clot retrieval. The G protein-coupled receptor GPR39 is expressed in brain peri-capillary pericytes, and has been implicated in microvascular regulation, but its role in stroke is unknown. We tested the hypothesis that GPR39 plays a protective role after stroke, in part due to preservation of microvascular perfusion. We generated GPR39 knockout (KO) mice and tested whether GPR39 gene deletion worsens capillary blood flow and exacerbates brain injury and functional deficit after focal cerebral ischemia. Stroke was induced in male and female GPR39 KO and WT littermates by 60-min middle cerebral artery occlusion (MCAO). Microvascular perfusion was assessed via capillary red blood cell (RBC) flux in deep cortical layers in vivo using optical microangiography (OMAG). Brain injury was assessed by measuring infarct size by 2,3,5-triphenyltetrazolium chloride staining at 24 h or brain atrophy at 3 weeks after ischemia. Pole and cylinder behavior tests were conducted to assess neurological function deficit at 1 and 3 weeks post-stroke. Male but not female GPR39 KO mice exhibited larger infarcts and lower capillary RBC flux than WT controls after stroke. Male GPR39 KO mice also exhibited worse neurologic deficit at 1 week post-stroke, though functional deficit disappeared in both groups by 3 weeks. GPR39 deletion worsens brain injury, microvascular perfusion, and neurological function after experimental stroke. Results indicate that GPR39 plays a sex-dependent role in re-establishing microvascular flow and limiting ischemic brain damage after stroke.
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Affiliation(s)
- Yifan Xu
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Wenri H Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Elyse M Allen
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Lev M Fedorov
- Transgenic Mouse Models Shared Resource, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Anthony P Barnes
- Department of Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Zu Yuan Qian
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Thierno Madjou Bah
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Yuandong Li
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington School of Medicine, Seattle, WA, USA
| | - Robert E Shangraw
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239-3098, USA.
- Department of Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, 97239, USA.
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6
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The Active Role of Pericytes During Neuroinflammation in the Adult Brain. Cell Mol Neurobiol 2023; 43:525-541. [PMID: 35195811 DOI: 10.1007/s10571-022-01208-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 02/13/2022] [Indexed: 12/11/2022]
Abstract
Microvessels in the central nervous system (CNS) have one of the highest populations of pericytes, indicating their crucial role in maintaining homeostasis. Pericytes are heterogeneous cells located around brain microvessels; they present three different morphologies along the CNS vascular tree: ensheathing, mesh, and thin-strand pericytes. At the arteriole-capillary transition ensheathing pericytes are found, while mesh and thin-strand pericytes are located at capillary beds. Brain pericytes are essential for the establishment and maintenance of the blood-brain barrier, which restricts the passage of soluble and potentially toxic molecules from the circulatory system to the brain parenchyma. Pericytes play a key role in regulating local inflammation at the CNS. Pericytes can respond differentially, depending on the degree of inflammation, by secreting a set of neurotrophic factors to promote cell survival and regeneration, or by potentiating inflammation through the release of inflammatory mediators (e.g., cytokines and chemokines), and the overexpression of cell adhesion molecules. Under inflammatory conditions, pericytes may regulate immune cell trafficking to the CNS and play a role in perpetuating local inflammation. In this review, we describe pericyte responses during acute and chronic neuroinflammation.
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Zhu W, Davis CM, Allen EM, Feller SL, Bah TM, Shangraw RE, Wang RK, Alkayed NJ. Sex Difference in Capillary Reperfusion After Transient Middle Cerebral Artery Occlusion in Diabetic Mice. Stroke 2023; 54:364-373. [PMID: 36689578 PMCID: PMC9883047 DOI: 10.1161/strokeaha.122.040972] [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: 08/14/2022] [Accepted: 12/13/2022] [Indexed: 01/25/2023]
Abstract
BACKGROUND Type 2 diabetes (DM2) exacerbates stroke injury, reduces efficacy of endovascular therapy, and worsens long-term functional outcome. Sex differences exist in stroke incidence, response to therapy, poststroke microvascular dysfunction, and functional recovery. In this study, we tested the hypotheses that poor outcome after stroke in the setting of DM2 is linked to impaired microvascular tissue reperfusion and that male and female DM2 mice exhibit different microvascular reperfusion response after transient middle cerebral artery occlusion (MCAO). METHODS Transient MCAO was induced for 60 minutes using an intraluminal filament in young adult DM2 and nondiabetic control male and female mice. Capillary flux in deep cortical layers was assessed using optical coherence tomography-based optical microangiography (OMAG), and associated regional brain infarct size was evaluated by hematoxylin and eosin staining. RESULTS Compared to baseline, MCAO reduced absolute capillary red blood cell flux by 84% at 24 hours post-MCAO in male DM2 (P<0.001) but not male control mice. When normalized to pre-MCAO baseline, red blood cell flux 24 hours after stroke was 64% lower in male DM2 mice than male nondiabetic controls (P<0.01). In females, MCAO decreased capillary flux by 48% at 24 hours post-MCAO compared with baseline in DM2 (P<0.05) but not in control mice. Red blood cell flux of female DM2 mice did not differ from that of nondiabetic controls either before or 24 hours after MCAO. Furthermore, normalized capillary flux 24 hours after MCAO failed to differ between female DM2 mice and nondiabetic controls. Concomitantly, male but not female DM2 mice experienced 25% larger infarct in caudate-putamen versus respective nondiabetic controls (P<0.05). CONCLUSIONS DM2 impairs capillary perfusion and exacerbates ischemic deep brain injury in male but not female young adult mice. Premenopausal females appear to be protected against DM2-related capillary dysfunction and brain injury.
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Affiliation(s)
- Wenbin Zhu
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Elyse M Allen
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Sarah L Feller
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Thierno M Bah
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Robert E Shangraw
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
| | - Ruikang K Wang
- Department of Bioengineering, University of Washington, Seattle, WA, USA 98195
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA 97239
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA 97239
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8
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Role of Vitamin D Deficiency in the Pathogenesis of Cardiovascular and Cerebrovascular Diseases. Nutrients 2023; 15:nu15020334. [PMID: 36678205 PMCID: PMC9864832 DOI: 10.3390/nu15020334] [Citation(s) in RCA: 30] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/12/2023] Open
Abstract
Deficiency in vitamin D (VitD), a lipid-soluble vitamin and steroid hormone, affects approximately 24% to 40% of the population of the Western world. In addition to its well-documented effects on the musculoskeletal system, VitD also contributes importantly to the promotion and preservation of cardiovascular health via modulating the immune and inflammatory functions and regulating cell proliferation and migration, endothelial function, renin expression, and extracellular matrix homeostasis. This brief overview focuses on the cardiovascular and cerebrovascular effects of VitD and the cellular, molecular, and functional changes that occur in the circulatory system in VitD deficiency (VDD). It explores the links among VDD and adverse vascular remodeling, endothelial dysfunction, vascular inflammation, and increased risk for cardiovascular and cerebrovascular diseases. Improved understanding of the complex role of VDD in the pathogenesis of atherosclerotic cardiovascular diseases, stroke, and vascular cognitive impairment is crucial for all cardiologists, dietitians, and geriatricians, as VDD presents an easy target for intervention.
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9
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Davis CM, Ibrahim AH, Alkayed NJ. Cytochrome P450-derived eicosanoids in brain: From basic discovery to clinical translation. ADVANCES IN PHARMACOLOGY 2023; 97:283-326. [DOI: 10.1016/bs.apha.2022.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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10
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Dufort C, Wang Y, Hu X. Microglia: Active participants in brain capillary function. J Cereb Blood Flow Metab 2022; 42:2161-2163. [PMID: 35942567 PMCID: PMC9580179 DOI: 10.1177/0271678x221119292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 07/05/2022] [Accepted: 07/12/2022] [Indexed: 11/17/2022]
Abstract
A recent study by Bisht, Okojie, and Sharma, et al. characterizes a population of capillary-associated microglia (CAM) whose cell bodies are positioned along small blood vessels in the healthy mouse brain. Through elegant, longitudinal intravital imaging of brain vasculature and CAMs, the authors have uncovered the significance of microglia in cerebral blood flow regulation. Further investigation into the functions of this CAM population and how they interact with surrounding cells within the neurovascular unit will improve our understanding of vascular regulation and cerebrovascular diseases.
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Affiliation(s)
- Connor Dufort
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Yangfan Wang
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Xiaoming Hu
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA
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11
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Davis CM, Zhang WH, Bah TM, Roese NE, Allen EM, Leung P, Boutros SJ, Marzulla T, Patel E, Nie X, Alkayed FN, Huang JH, Jensen MA, Raber J, Pike MM, Alkayed NJ. Age-dependent cognitive impairment, hydrocephalus and leukocyte infiltration in transgenic mice with endothelial expression of human EPHX2. NPJ AGING 2022; 8:9. [PMID: 35927273 PMCID: PMC9256583 DOI: 10.1038/s41514-022-00090-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 05/31/2022] [Indexed: 12/30/2022]
Abstract
Soluble epoxide hydrolase (sEH) is upregulated in microvascular endothelium of human brain with vascular cognitive impairment (VCI). Transgenic endothelial expression of human sEH in mice (Tie2hsEH) induces endothelial dysfunction (ED), a pathogenetic mechanism of VCI. We sought to determine if endothelial upregulation of sEH is sufficient to cause cognitive impairment, and if cognitive impairment due to chronic hypoperfusion induced by unilateral common carotid artery occlusion (CCAO) is exacerbated in Tie2hsEH mice. Behavioral performance was assessed by the open field, rotarod, novel object, Morris water maze and fear conditioning tests. Cerebral blood flow and brain morphology were evaluated by MRI, and inflammatory changes investigated using immunohistochemistry and flow cytometry. We demonstrate that transgenic endothelial expression of sEH is sufficient to induce cognitive impairment, associated with leukocyte infiltration, brain atrophy and accelerated, age-dependent ventriculomegaly, identifying ED and sEH upregulation as potential underlying mechanisms and therapeutic targets for VCI.
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Affiliation(s)
- Catherine M Davis
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Wenri H Zhang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Thierno M Bah
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Natalie E Roese
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Elyse M Allen
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Philberta Leung
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Sydney J Boutros
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Tessa Marzulla
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Esha Patel
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Xiao Nie
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Farah N Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Justin H Huang
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Michael A Jensen
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, 97239, USA
- Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Martin M Pike
- Advanced Imaging Research Center, Oregon Health & Science University, Portland, OR, 97239, USA
| | - Nabil J Alkayed
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, 97239, USA.
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, 97239, USA.
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12
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Lansdell TA, Chambers LC, Dorrance AM. Endothelial Cells and the Cerebral Circulation. Compr Physiol 2022; 12:3449-3508. [PMID: 35766836 DOI: 10.1002/cphy.c210015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Endothelial cells form the innermost layer of all blood vessels and are the only vascular component that remains throughout all vascular segments. The cerebral vasculature has several unique properties not found in the peripheral circulation; this requires that the cerebral endothelium be considered as a unique entity. Cerebral endothelial cells perform several functions vital for brain health. The cerebral vasculature is responsible for protecting the brain from external threats carried in the blood. The endothelial cells are central to this requirement as they form the basis of the blood-brain barrier. The endothelium also regulates fibrinolysis, thrombosis, platelet activation, vascular permeability, metabolism, catabolism, inflammation, and white cell trafficking. Endothelial cells regulate the changes in vascular structure caused by angiogenesis and artery remodeling. Further, the endothelium contributes to vascular tone, allowing proper perfusion of the brain which has high energy demands and no energy stores. In this article, we discuss the basic anatomy and physiology of the cerebral endothelium. Where appropriate, we discuss the detrimental effects of high blood pressure on the cerebral endothelium and the contribution of cerebrovascular disease endothelial dysfunction and dementia. © 2022 American Physiological Society. Compr Physiol 12:3449-3508, 2022.
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Affiliation(s)
- Theresa A Lansdell
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Laura C Chambers
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Anne M Dorrance
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, 48824, USA
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13
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Keep RF, Jones HC, Drewes LR. Advances in brain barriers and brain fluids research in 2021: great progress in a time of adversity. Fluids Barriers CNS 2022; 19:48. [PMID: 35681151 PMCID: PMC9178944 DOI: 10.1186/s12987-022-00343-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Accepted: 05/16/2022] [Indexed: 11/10/2022] Open
Abstract
This editorial highlights advances in brain barrier and brain fluid research in 2021. It covers research on components of the blood–brain barrier, neurovascular unit and brain fluid systems; how brain barriers and brain fluid systems are impacted by neurological disorders and their role in disease progression; and advances in strategies for treating such disorders.
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Affiliation(s)
- Richard F Keep
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI, 48109-2200, USA.
| | | | - Lester R Drewes
- Department of Biomedical Sciences, University of Minnesota Medical School Duluth, Duluth, MN, 55812, USA
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14
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Zhu WM, Neuhaus A, Beard DJ, Sutherland BA, DeLuca GC. Neurovascular coupling mechanisms in health and neurovascular uncoupling in Alzheimer's disease. Brain 2022; 145:2276-2292. [PMID: 35551356 PMCID: PMC9337814 DOI: 10.1093/brain/awac174] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 11/25/2022] Open
Abstract
To match the metabolic demands of the brain, mechanisms have evolved to couple neuronal activity to vasodilation, thus increasing local cerebral blood flow and delivery of oxygen and glucose to active neurons. Rather than relying on metabolic feedback signals such as the consumption of oxygen or glucose, the main signalling pathways rely on the release of vasoactive molecules by neurons and astrocytes, which act on contractile cells. Vascular smooth muscle cells and pericytes are the contractile cells associated with arterioles and capillaries, respectively, which relax and induce vasodilation. Much progress has been made in understanding the complex signalling pathways of neurovascular coupling, but issues such as the contributions of capillary pericytes and astrocyte calcium signal remain contentious. Study of neurovascular coupling mechanisms is especially important as cerebral blood flow dysregulation is a prominent feature of Alzheimer’s disease. In this article we will discuss developments and controversies in the understanding of neurovascular coupling and finish by discussing current knowledge concerning neurovascular uncoupling in Alzheimer’s disease.
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Affiliation(s)
- Winston M Zhu
- Oxford Medical School, University of Oxford, Oxford, UK
| | - Ain Neuhaus
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Daniel J Beard
- Acute Stroke Programme, Radcliffe Department of Medicine, University of Oxford, Oxford, UK.,School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Brad A Sutherland
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, Australia
| | - Gabriele C DeLuca
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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15
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Alkayed NJ, Cao Z, Qian ZY, Nagarajan S, Liu X, Nelson JW, Xie F, Li B, Fan W, Liu L, Grafe MR, Davis CM, Xiao X, Barnes AP, Kaul S. Control of Coronary Vascular Resistance by Eicosanoids via a Novel GPCR. Am J Physiol Cell Physiol 2022; 322:C1011-C1021. [PMID: 35385329 PMCID: PMC9255704 DOI: 10.1152/ajpcell.00454.2021] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Arachidonic acid metabolites epoxyeicosatrienoates (EETs) and hydroxyeicosatetraenoates (HETEs) are important regulators of myocardial blood flow and coronary vascular resistance (CVR), but their mechanisms of action are not fully understood. We applied a chemoproteomics strategy using a clickable photoaffinity probe to identify G protein coupled receptor 39 (GPR39) as a microvascular smooth muscle cell (mVSMC) receptor selective for two endogenous eicosanoids, 15-HETE and 14,15-EET, which act on the receptor to oppose each other's activity. The former increases mVSMC intracellular calcium via GPR39 and augments coronary microvascular resistance, and the latter inhibits these actions. Furthermore, we find that the efficacy of both ligands is potentiated by zinc acting as an allosteric modulator. Measurements of coronary perfusion pressure (CPP) in GPR39-null hearts using the Langendorff preparation indicate the receptor senses these eicosanoids to regulate microvascular tone. These results implicate GPR39 as an eicosanoid receptor and key regulator of myocardial tissue perfusion. Our findings will have a major impact on understanding the roles of eicosanoids in cardiovascular physiology and disease and provide an opportunity for the development of novel GPR39-targeting therapies for cardiovascular disease.
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Affiliation(s)
- Nabil J Alkayed
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Zhiping Cao
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Zu Yuan Qian
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Shanthi Nagarajan
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States.,Medicinal Chemistry Core, Oregon Health & Science University, Portland, Oregon, United States
| | - Xuehong Liu
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Jonathan W Nelson
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Fuchun Xie
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon, United States
| | - Bingbing Li
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon, United States
| | - Wei Fan
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Lijuan Liu
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Marjorie R Grafe
- DDepartment of Pathology, Oregon Health & Science University, Portland, Oregon, United States
| | - Catherine M Davis
- Department of Anesthesiology and Perioperative Medicine, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Xiangshu Xiao
- Department of Physiology and Pharmacology, Oregon Health & Science University, Portland, Oregon, United States.,The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Anthony P Barnes
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
| | - Sanjiv Kaul
- The Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, United States
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16
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Shaw K, Boyd K, Anderle S, Hammond-Haley M, Amin D, Bonnar O, Hall CN. Gradual Not Sudden Change: Multiple Sites of Functional Transition Across the Microvascular Bed. Front Aging Neurosci 2022; 13:779823. [PMID: 35237142 PMCID: PMC8885127 DOI: 10.3389/fnagi.2021.779823] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 12/20/2021] [Indexed: 01/03/2023] Open
Abstract
In understanding the role of the neurovascular unit as both a biomarker and target for disease interventions, it is vital to appreciate how the function of different components of this unit change along the vascular tree. The cells of the neurovascular unit together perform an array of vital functions, protecting the brain from circulating toxins and infection, while providing nutrients and clearing away waste products. To do so, the brain's microvasculature dilates to direct energy substrates to active neurons, regulates access to circulating immune cells, and promotes angiogenesis in response to decreased blood supply, as well as pulsating to help clear waste products and maintain the oxygen supply. Different parts of the cerebrovascular tree contribute differently to various aspects of these functions, and previously, it has been assumed that there are discrete types of vessel along the vascular network that mediate different functions. Another option, however, is that the multiple transitions in function that occur across the vascular network do so at many locations, such that vascular function changes gradually, rather than in sharp steps between clearly distinct vessel types. Here, by reference to new data as well as by reviewing historical and recent literature, we argue that this latter scenario is likely the case and that vascular function gradually changes across the network without clear transition points between arteriole, precapillary arteriole and capillary. This is because classically localized functions are in fact performed by wide swathes of the vasculature, and different functional markers start and stop being expressed at different points along the vascular tree. Furthermore, vascular branch points show alterations in their mural cell morphology that suggest functional specializations irrespective of their position within the network. Together this work emphasizes the need for studies to consider where transitions of different functions occur, and the importance of defining these locations, in order to better understand the vascular network and how to target it to treat disease.
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Affiliation(s)
- Kira Shaw
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | - Katie Boyd
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | - Silvia Anderle
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
| | | | - Davina Amin
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
| | - Orla Bonnar
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital and Harvard Medical School, Charlestown Navy Yard, MA, United States
| | - Catherine N. Hall
- Sussex Neuroscience, School of Psychology, University of Sussex, Falmer, United Kingdom
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17
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Hartmann DA, Coelho-Santos V, Shih AY. Pericyte Control of Blood Flow Across Microvascular Zones in the Central Nervous System. Annu Rev Physiol 2022; 84:331-354. [PMID: 34672718 PMCID: PMC10480047 DOI: 10.1146/annurev-physiol-061121-040127] [Citation(s) in RCA: 70] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The vast majority of the brain's vascular length is composed of capillaries, where our understanding of blood flow control remains incomplete. This review synthesizes current knowledge on the control of blood flow across microvascular zones by addressing issues with nomenclature and drawing on new developments from in vivo optical imaging and single-cell transcriptomics. Recent studies have highlighted important distinctions in mural cell morphology, gene expression, and contractile dynamics, which can explain observed differences in response to vasoactive mediators between arteriole, transitional, and capillary zones. Smooth muscle cells of arterioles and ensheathing pericytes of the arteriole-capillary transitional zone control large-scale, rapid changes in blood flow. In contrast, capillary pericytes downstream of the transitional zone act on slower and smaller scales and are involved in establishing resting capillary tone and flow heterogeneity. Many unresolved issues remain, including the vasoactive mediators that activate the different pericyte types in vivo, the role of pericyte-endothelial communication in conducting signals from capillaries to arterioles, and how neurological disease affects these mechanisms.
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Affiliation(s)
- David A Hartmann
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California, USA
| | - Vanessa Coelho-Santos
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, Washington, USA;
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
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18
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Procter TV, Williams A, Montagne A. Interplay between brain pericytes and endothelial cells in dementia. THE AMERICAN JOURNAL OF PATHOLOGY 2021; 191:1917-1931. [PMID: 34329605 DOI: 10.1016/j.ajpath.2021.07.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/23/2021] [Accepted: 07/02/2021] [Indexed: 02/06/2023]
Abstract
Dementia is becoming an increasingly important disease due to an aging population and limited treatment options. Cerebral small vessel disease (cSVD) and Alzheimer's disease (AD) are the two most common causes of dementia with vascular dysfunction being a large component of both their pathophysiologies. The neurogliovascular unit (NVU), and in particular the blood-brain barrier (BBB) are required for maintaining brain homeostasis. A complex interaction exists between the endothelial cells, which line the blood vessels and pericytes, which surround them in the NVU. Disruption of the BBB occurs in dementia precipitating cognitive decline. In this review, we highlight how dysfunction of the endothelial-pericyte crosstalk contributes to dementia, focusing on cSVD and AD. This review examines how loss of pericyte coverage occurs and subsequent downstream changes. Furthermore, it examines how disruption to intimate crosstalk between endothelial cells and pericytes leads to alterations in cerebral blood flow, transcription, neuroinflammation and transcytosis contributing to breakdown of the BBB. This review illustrates how cumulation of loss of endothelial-pericyte crosstalk is a major driving force in dementia pathology.
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Affiliation(s)
- Tessa V Procter
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK
| | - Anna Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh BioQuarter, Edinburgh, UK; UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK
| | - Axel Montagne
- UK Dementia Research Institute, Edinburgh Medical School, University of Edinburgh, Edinburgh, UK; Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK.
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19
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Chen Y, Zhang J. How Energy Supports Our Brain to Yield Consciousness: Insights From Neuroimaging Based on the Neuroenergetics Hypothesis. Front Syst Neurosci 2021; 15:648860. [PMID: 34295226 PMCID: PMC8291083 DOI: 10.3389/fnsys.2021.648860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2021] [Accepted: 05/26/2021] [Indexed: 11/13/2022] Open
Abstract
Consciousness is considered a result of specific neuronal processes and mechanisms in the brain. Various suggested neuronal mechanisms, including the information integration theory (IIT), global neuronal workspace theory (GNWS), and neuronal construction of time and space as in the context of the temporospatial theory of consciousness (TTC), have been laid forth. However, despite their focus on different neuronal mechanisms, these theories neglect the energetic-metabolic basis of the neuronal mechanisms that are supposed to yield consciousness. Based on the findings of physiology-induced (sleep), pharmacology-induced (general anesthesia), and pathology-induced [vegetative state/unresponsive wakeful syndrome (VS/UWS)] loss of consciousness in both human subjects and animals, we, in this study, suggest that the energetic-metabolic processes focusing on ATP, glucose, and γ-aminobutyrate/glutamate are indispensable for functional connectivity (FC) of normal brain networks that renders consciousness possible. Therefore, we describe the energetic-metabolic predispositions of consciousness (EPC) that complement the current theories focused on the neural correlates of consciousness (NCC).
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Affiliation(s)
- Yali Chen
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China
| | - Jun Zhang
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, Shanghai, China.,Department of Oncology, Shanghai Medical college, Fudan University, Shanghai, China
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20
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Alkayed NJ, Cipolla MJ. Vascular Biology. Stroke 2021; 52:2440-2441. [PMID: 34078110 DOI: 10.1161/strokeaha.121.033556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Nabil J Alkayed
- Department of Anesthesiology and Perioperative Medicine, Portland, OR (N.J.A.)
| | - Marilyn J Cipolla
- Department of Neurological Science, University of Vermont Larner College of Medicine, Burlington (M.J.C.)
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