1
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Zhang C, Jamshidi M, Delafontaine-Martel P, Linninger AA, Lesage F. Evaluation of cerebral microcirculation in a mouse model of systemic inflammation. NEUROPHOTONICS 2024; 11:035003. [PMID: 39011517 PMCID: PMC11249390 DOI: 10.1117/1.nph.11.3.035003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 07/17/2024]
Abstract
Significance Perturbations in the microcirculatory system have been observed in neurological conditions, such as Alzheimer's disease or systemic inflammation. However, changes occurring at the level of the capillary are difficult to translate to biomarkers that could be measured macroscopically. Aim We aim to evaluate whether transit time changes reflect capillary stalling and to what degree. Approach We employ a combined spectral optical coherence tomography (OCT) and fluorescence optical imaging (FOI) system to investigate the relation between capillary stalling and transit time in a mouse model of systemic inflammation induced by intraperitoneal injection of lipopolysaccharide. Angiograms are obtained using OCT, and fluorescence signal images are acquired by the FOI system upon intravenous injection of fluorescein isothiocyanate via a catheter inserted into the tail vein. Results Our findings reveal that lipopolysaccharide (LPS) administration significantly increases both the percentage and duration of capillary stalling compared to mice receiving a 0.9% saline injection. Moreover, LPS-induced mice exhibit significantly prolonged arteriovenous transit time compared to control mice. Conclusions These observations suggest that capillary stalling, induced by inflammation, modulates cerebral mean transit time, a measure that has translational potential.
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Affiliation(s)
- Cong Zhang
- Polytechnique Montreal, Department of Electrical Engineering, Montreal, Quebec, Canada
- Montreal Heart Institute, Research center, Montreal, Quebec, Canada
| | - Mohammad Jamshidi
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, Illinois, United States
| | - Patrick Delafontaine-Martel
- Polytechnique Montreal, Department of Electrical Engineering, Montreal, Quebec, Canada
- Montreal Heart Institute, Research center, Montreal, Quebec, Canada
| | - Andreas A Linninger
- University of Illinois at Chicago, Department of Biomedical Engineering, Chicago, Illinois, United States
- University of Illinois at Chicago, Department of Neurosurgery, Chicago, Illinois, United States
| | - Frédéric Lesage
- Polytechnique Montreal, Department of Electrical Engineering, Montreal, Quebec, Canada
- Montreal Heart Institute, Research center, Montreal, Quebec, Canada
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2
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Sun T, Zhao H, Hu L, Shao X, Lu Z, Wang Y, Ling P, Li Y, Zeng K, Chen Q. Enhanced optical imaging and fluorescent labeling for visualizing drug molecules within living organisms. Acta Pharm Sin B 2024; 14:2428-2446. [PMID: 38828150 PMCID: PMC11143489 DOI: 10.1016/j.apsb.2024.01.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 01/07/2024] [Accepted: 01/25/2024] [Indexed: 06/05/2024] Open
Abstract
The visualization of drugs in living systems has become key techniques in modern therapeutics. Recent advancements in optical imaging technologies and molecular design strategies have revolutionized drug visualization. At the subcellular level, super-resolution microscopy has allowed exploration of the molecular landscape within individual cells and the cellular response to drugs. Moving beyond subcellular imaging, researchers have integrated multiple modes, like optical near-infrared II imaging, to study the complex spatiotemporal interactions between drugs and their surroundings. By combining these visualization approaches, researchers gain supplementary information on physiological parameters, metabolic activity, and tissue composition, leading to a comprehensive understanding of drug behavior. This review focuses on cutting-edge technologies in drug visualization, particularly fluorescence imaging, and the main types of fluorescent molecules used. Additionally, we discuss current challenges and prospects in targeted drug research, emphasizing the importance of multidisciplinary cooperation in advancing drug visualization. With the integration of advanced imaging technology and molecular design, drug visualization has the potential to redefine our understanding of pharmacology, enabling the analysis of drug micro-dynamics in subcellular environments from new perspectives and deepening pharmacological research to the levels of the cell and organelles.
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Affiliation(s)
- Ting Sun
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- Institute of Biochemical and Biotechnological Drugs, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
| | - Huanxin Zhao
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Luyao Hu
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Xintian Shao
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- School of Life Sciences, Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Zhiyuan Lu
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
| | - Yuli Wang
- Tianjin Pharmaceutical DA REN TANG Group Corporation Limited Traditional Chinese Pharmacy Research Institute, Tianjin 300457, China
- Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemistry Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Peixue Ling
- Institute of Biochemical and Biotechnological Drugs, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, Jinan 250012, China
- Key Laboratory of Biopharmaceuticals, Postdoctoral Scientific Research Workstation, Shandong Academy of Pharmaceutical Science, Jinan 250098, China
| | - Yubo Li
- School of Chinese Materia Medica, Tianjin University of Traditional Chinese Medicine, Tianjin 301617, China
| | - Kewu Zeng
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Qixin Chen
- School of Pharmaceutical Sciences, National Key Laboratory of Advanced Drug Delivery System, Medical Science and Technology Innovation Center, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250062, China
- Departments of Diagnostic Radiology, Surgery, Chemical and Biomolecular Engineering, and Biomedical Engineering, Yong Loo Lin School of Medicine and College of Design and Engineering, National University of Singapore, Singapore 119074, Singapore
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3
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Zarate SM, Huntington TE, Bagher P, Srinivasan R. Aging reduces calreticulin expression and alters spontaneous calcium signals in astrocytic endfeet of the mouse dorsolateral striatum. NPJ AGING 2023; 9:5. [PMID: 37002232 PMCID: PMC10066375 DOI: 10.1038/s41514-023-00102-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Accepted: 03/15/2023] [Indexed: 04/03/2023]
Abstract
Aging-related impairment of the blood brain barrier (BBB) and neurovascular unit (NVU) increases the risk for neurodegeneration. Among various cells that participate in BBB and NVU function, calcium signals in astrocytic endfeet are crucial for maintaining BBB and NVU integrity. To assess if aging is associated with altered calcium signals within astrocytic endfeet of the dorsolateral striatum (DLS), we expressed GCaMP6f in DLS astrocytes of young (3-4 months), middle-aged (12-15 months) and aging (20-30 months) mice. Compared to endfeet in young mice, DLS endfeet in aging mice demonstrated decreased calreticulin expression, and alterations to both spontaneous membrane-associated and mitochondrial calcium signals. While young mice required both extracellular and endoplasmic reticulum calcium sources for endfoot signals, middle-aged and aging mice showed heavy dependence on endoplasmic reticulum calcium. Thus, astrocytic endfeet show significant changes in calcium buffering and sources throughout the lifespan, which is important for understanding mechanisms by which aging impairs the BBB and NVU.
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Affiliation(s)
- Sara M Zarate
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA
| | - Taylor E Huntington
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA
- Texas A&M Institute for Neuroscience (TAMIN), Texas A&M University, College Station, TX, 77843, USA
| | - Pooneh Bagher
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Rahul Srinivasan
- Department of Neuroscience & Experimental Therapeutics, Texas A&M University School of Medicine, 8447 Riverside Pkwy, Bryan, TX, 77807, USA.
- Texas A&M Institute for Neuroscience (TAMIN), Texas A&M University, College Station, TX, 77843, USA.
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4
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Yin L, Gao DS, Hu JM, Zhong C, Xi W. Long-term development of dynamic changes in neurovascular coupling after acute temporal lobe epilepsy. Brain Res 2022; 1784:147858. [PMID: 35245486 DOI: 10.1016/j.brainres.2022.147858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 02/23/2022] [Accepted: 02/27/2022] [Indexed: 12/25/2022]
Abstract
Epilepsy is an abnormal brain state that may be induced by synchronous neuronal activation and also abnormalities in energy metabolism or the oxygen supply vascular system. Neurovascular coupling (NVC), the relationship between neuron, capillary, and penetrating artery, remains unexplored on a fine-scale with respect to the pathology process after acute temporal lobe epilepsy (TLE). Here we use two-photon microscopy (TPM) to provide high temporal-spatial resolution imaging to identify changes in NVC during spontaneous and electro-stimulated (ES) states in awake mice. Implantation of a long-term craniotomy window allowed TPM recording of the pathological development after the acute Kainic Acid temporal lobe epilepsy model. Our results provide direct evidence that the capillary and penetrating artery are not correlated to rhythmic neuronal activity during acute epilepsy. During the CSD period, NVC shows a strong correlation. We demonstrate that NVC exhibits nonlinear dynamics after status epilepticus. Furthermore, the vascular correlation to neuronal signals in spontaneous and ES states shows dynamic changes which correlate to the evolution after acute TLE. Understanding NVC in all TLE stages, from the acute through the TLE pathological development, may provide new therapeutic pathways.
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Affiliation(s)
- Liu Yin
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China
| | - Dave Schwinn Gao
- Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Jiefang Road 88th, Hangzhou, 310016, PR China
| | - Jia Ming Hu
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China
| | - Chen Zhong
- Key Laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province, College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China. Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China. Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
| | - Wang Xi
- Interdisciplinary Institute of Neuroscience and Technology, Department of Anesthesiology, the Second Affiliated Hospital, School of Medicine, Zhejiang University, Kaixuan Road 258th, Hangzhou, 310020, PR China; Key Laboratory of Biomedical Engineering of Ministry of Education, College of Biomedical Engineering and instrument Science, Zhejiang University, Hangzhou 310027, PR China.
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5
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Abstract
In 2001, the concept of the neurovascular unit was introduced at the Stroke Progress Review Group meeting. The neurovascular unit is an important element of the health and disease status of blood vessels and nerves in the central nervous system. Since then, the neurovascular unit has attracted increasing interest from research teams, who have contributed greatly to the prevention, treatment, and prognosis of stroke and neurodegenerative diseases. However, additional research is needed to establish an efficient, low-cost, and low-energy in vitro model of the neurovascular unit, as well as enable noninvasive observation of neurovascular units in vivo and in vitro. In this review, we first summarize the composition of neurovascular units, then investigate the efficacy of different types of stem cells and cell culture methods in the construction of neurovascular unit models, and finally assess the progress of imaging methods used to observe neurovascular units in recent years and their positive role in the monitoring and investigation of the mechanisms of a variety of central nervous system diseases.
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Affiliation(s)
- Taiwei Dong
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, China
| | - Min Li
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, China
| | - Feng Gao
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, China
| | - Peifeng Wei
- College of Pharmacy, Shaanxi University of Chinese Medicine, Xianyang, Shaanxi Province, China
| | - Jian Wang
- College of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan Provinve, China
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6
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van Lanen RH, Melchers S, Hoogland G, Schijns OE, Zandvoort MAV, Haeren RH, Rijkers K. Microvascular changes associated with epilepsy: A narrative review. J Cereb Blood Flow Metab 2021; 41:2492-2509. [PMID: 33866850 PMCID: PMC8504411 DOI: 10.1177/0271678x211010388] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The blood-brain barrier (BBB) is dysfunctional in temporal lobe epilepsy (TLE). In this regard, microvascular changes are likely present. The aim of this review is to provide an overview of the current knowledge on microvascular changes in epilepsy, and includes clinical and preclinical evidence of seizure induced angiogenesis, barriergenesis and microcirculatory alterations. Anatomical studies show increased microvascular density in the hippocampus, amygdala, and neocortex accompanied by BBB leakage in various rodent epilepsy models. In human TLE, a decrease in afferent vessels, morphologically abnormal vessels, and an increase in endothelial basement membranes have been observed. Both clinical and experimental evidence suggests that basement membrane changes, such as string vessels and protrusions, indicate and visualize a misbalance between endothelial cell proliferation and barriergenesis. Vascular endothelial growth factor (VEGF) appears to play a crucial role. Following an altered vascular anatomy, its physiological functioning is affected as expressed by neurovascular decoupling that subsequently leads to hypoperfusion, disrupted parenchymal homeostasis and potentially to seizures". Thus, epilepsy might be a condition characterized by disturbed cerebral microvasculature in which VEGF plays a pivotal role. Additional physiological data from patients is however required to validate findings from models and histological studies on patient biopsies.
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Affiliation(s)
- Rick Hgj van Lanen
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Stan Melchers
- Faculty of Health Medicine and Life Sciences, Maastricht University, Maastricht, the Netherlands
| | - Govert Hoogland
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Academic Center for Epileptology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Olaf Emg Schijns
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Academic Center for Epileptology, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Marc Amj van Zandvoort
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Department of Molecular Cell Biology, School for Mental Health and Neuroscience, Maastricht University Medical Center, Maastricht, the Netherlands.,School for Cardiovascular Diseases, Maastricht University Medical Center, Maastricht, the Netherlands
| | - Roel Hl Haeren
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands.,Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland
| | - Kim Rijkers
- Department of Neurosurgery, Maastricht University Medical Center, Maastricht, the Netherlands.,School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Academic Center for Epileptology, Maastricht University Medical Center, Maastricht, the Netherlands
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7
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Heuser K, Enger R. Astrocytic Ca 2+ Signaling in Epilepsy. Front Cell Neurosci 2021; 15:695380. [PMID: 34335188 PMCID: PMC8320018 DOI: 10.3389/fncel.2021.695380] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/16/2021] [Indexed: 01/10/2023] Open
Abstract
Epilepsy is one of the most common neurological disorders – estimated to affect at least 65 million worldwide. Most of the epilepsy research has so far focused on how to dampen neuronal discharges and to explain how changes in intrinsic neuronal activity or network function cause seizures. As a result, pharmacological therapy has largely been limited to symptomatic treatment targeted at neurons. Given the expanding spectrum of functions ascribed to the non-neuronal constituents of the brain, in both physiological brain function and in brain disorders, it is natural to closely consider the roles of astrocytes in epilepsy. It is now widely accepted that astrocytes are key controllers of the composition of the extracellular fluids, and may directly interact with neurons by releasing gliotransmitters. A central tenet is that astrocytic intracellular Ca2+ signals promote release of such signaling substances, either through synaptic or non-synaptic mechanisms. Accruing evidence suggests that astrocytic Ca2+ signals play important roles in both seizures and epilepsy, and this review aims to highlight the current knowledge of the roles of this central astrocytic signaling mechanism in ictogenesis and epileptogenesis.
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Affiliation(s)
- Kjell Heuser
- Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
| | - Rune Enger
- Letten Centre and GliaLab, Division of Anatomy, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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8
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Lim HK, You N, Bae S, Kang BM, Shon YM, Kim SG, Suh M. Differential contribution of excitatory and inhibitory neurons in shaping neurovascular coupling in different epileptic neural states. J Cereb Blood Flow Metab 2021; 41:1145-1161. [PMID: 32669018 PMCID: PMC8054729 DOI: 10.1177/0271678x20934071] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Understanding the neurovascular coupling (NVC) underlying hemodynamic changes in epilepsy is crucial to properly interpreting functional brain imaging signals associated with epileptic events. However, how excitatory and inhibitory neurons affect vascular responses in different epileptic states remains unknown. We conducted real-time in vivo measurements of cerebral blood flow (CBF), vessel diameter, and excitatory and inhibitory neuronal calcium signals during recurrent focal seizures. During preictal states, decreases in CBF and arteriole diameter were closely related to decreased γ-band local field potential (LFP) power, which was linked to relatively elevated excitatory and reduced inhibitory neuronal activity levels. Notably, this preictal condition was followed by a strengthened ictal event. In particular, the preictal inhibitory activity level was positively correlated with coherent oscillating activity specific to inhibitory neurons. In contrast, ictal states were characterized by elevated synchrony in excitatory neurons. Given these findings, we suggest that excitatory and inhibitory neurons differentially contribute to shaping the ictal and preictal neural states, respectively. Moreover, the preictal vascular activity, alongside with the γ-band, may reflect the relative levels of excitatory and inhibitory neuronal activity, and upcoming ictal activity. Our findings provide useful insights into how perfusion signals of different epileptic states are related in terms of NVC.
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Affiliation(s)
- Hyun-Kyoung Lim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biological Sciences, Sungkyunkwan University, Suwon, South Korea
| | - Nayeon You
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Sungjun Bae
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Bok-Man Kang
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Young-Min Shon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon, South Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon, South Korea
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9
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In Vitro and In Vivo Study of the Short-Term Vasomotor Response during Epileptic Seizures. Brain Sci 2020; 10:brainsci10120942. [PMID: 33297329 PMCID: PMC7762235 DOI: 10.3390/brainsci10120942] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 11/29/2020] [Accepted: 11/30/2020] [Indexed: 02/07/2023] Open
Abstract
Epilepsy remains one of the most common brain disorders, and the different types of epilepsy encompass a wide variety of physiological manifestations. Clinical and preclinical findings indicate that cerebral blood flow is usually focally increased at seizure onset, shortly after the beginning of ictal events. Nevertheless, many questions remain about the relationship between vasomotor changes in the epileptic foci and the epileptic behavior of neurons and astrocytes. To study this relationship, we performed a series of in vitro and in vivo experiments using the 4-aminopyridine model of epileptic seizures. It was found that in vitro pathological synchronization of neurons and the depolarization of astrocytes is accompanied by rapid short-term vasoconstriction, while in vivo vasodilation during the seizure prevails. We suggest that vasomotor activity during epileptic seizures is a correlate of the complex, self-sustained response that includes neuronal and astrocytic oscillations, and that underlies the clinical presentation of epilepsy.
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10
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Tran CHT, George AG, Teskey GC, Gordon GR. Seizures elevate gliovascular unit Ca2+ and cause sustained vasoconstriction. JCI Insight 2020; 5:136469. [PMID: 33004688 PMCID: PMC7566700 DOI: 10.1172/jci.insight.136469] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/20/2020] [Indexed: 12/31/2022] Open
Abstract
Seizures can result in a severe hypoperfusion/hypoxic attack that causes postictal memory and behavioral impairments. However, neither postictal changes to microvasculature nor Ca2+ changes in key cell types controlling blood perfusion have been visualized in vivo, leaving essential components of the underlying cellular mechanisms unclear. Here, we use 2-photon microvascular and Ca2+ imaging in awake mice to show that seizures result in a robust vasoconstriction of cortical penetrating arterioles, which temporally mirrors the prolonged postictal hypoxia. The vascular effect was dependent on cyclooxygenase 2, as pretreatment with ibuprofen prevented postictal vasoconstriction. Moreover, seizures caused a rapid elevation in astrocyte endfoot Ca2+ that was confined to the seizure period, and vascular smooth muscle cells displayed a significant increase in Ca2+ both during and following seizures, lasting up to 75 minutes. Our data show enduring postictal vasoconstriction and temporal activities of 2 cell types within the neurovascular unit that are associated with seizure-induced hypoperfusion/hypoxia. These findings support prevention of this event may be a novel and tractable treatment strategy in patients with epilepsy who experience extended postseizure impairments. Seizures cause enduring microvascular constriction via long lasting calcium elevations in vascular smooth muscle cells.
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Affiliation(s)
- Cam Ha T Tran
- Hotchkiss Brain Institute and.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
| | - Antis G George
- Hotchkiss Brain Institute and.,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - G Campbell Teskey
- Hotchkiss Brain Institute and.,Department of Cell Biology and Anatomy, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Grant R Gordon
- Hotchkiss Brain Institute and.,Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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11
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Kim YS, Choi J, Yoon BE. Neuron-Glia Interactions in Neurodevelopmental Disorders. Cells 2020; 9:cells9102176. [PMID: 32992620 PMCID: PMC7601502 DOI: 10.3390/cells9102176] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 09/24/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
Recent studies have revealed synaptic dysfunction to be a hallmark of various psychiatric diseases, and that glial cells participate in synapse formation, development, and plasticity. Glial cells contribute to neuroinflammation and synaptic homeostasis, the latter being essential for maintaining the physiological function of the central nervous system (CNS). In particular, glial cells undergo gliotransmission and regulate neuronal activity in tripartite synapses via ion channels (gap junction hemichannel, volume regulated anion channel, and bestrophin-1), receptors (for neurotransmitters and cytokines), or transporters (GLT-1, GLAST, and GATs) that are expressed on glial cell membranes. In this review, we propose that dysfunction in neuron-glia interactions may contribute to the pathogenesis of neurodevelopmental disorders. Understanding the mechanisms of neuron-glia interaction for synapse formation and maturation will contribute to the development of novel therapeutic targets of neurodevelopmental disorders.
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Affiliation(s)
- Yoo Sung Kim
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
| | - Juwon Choi
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
| | - Bo-Eun Yoon
- Department of Molecular Biology, Dankook University, Cheonan 31116, Korea; (Y.S.K.); (J.C.)
- Department of Nanobiomedical science, Dankook University, Cheonan 31116, Korea
- Correspondence: ; Tel.: +82-41-529-6085
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12
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Pardridge WM. The Isolated Brain Microvessel: A Versatile Experimental Model of the Blood-Brain Barrier. Front Physiol 2020; 11:398. [PMID: 32457645 PMCID: PMC7221163 DOI: 10.3389/fphys.2020.00398] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 04/02/2020] [Indexed: 12/12/2022] Open
Abstract
A versatile experimental model for the investigation of the blood-brain barrier (BBB), including the neuro-vascular unit, is the isolated brain microvessel preparation. Brain microvessels are primarily comprised of endothelial cells, but also include pericytes, pre-capillary arteriolar smooth muscle cells, astrocyte foot processes, and occasional nerve endings. These microvessels can be isolated from brain with a 3 h procedure, and the microvessels are free of brain parenchyma. Brain microvessels have been isolated from fresh animal brain, fresh human brain obtained at neurosurgery, as well as fresh or frozen autopsy human brain. Brain microvessels are the starting point for isolation of brain microvessel RNA, which then enables the production of BBB cDNA libraries and a genomics analysis of the brain microvasculature. Brain microvessels, combined with quantitative targeted absolute proteomics, allow for the quantitation of specific transporters or receptors expressed at the brain microvasculature. Brain microvessels, combined with specific antibodies and immune labeling of isolated capillaries, allow for the cellular location of proteins expressed within the neuro-vascular unit. Isolated brain microvessels can be used as an “in vitro” preparation of the BBB for the study of the kinetic parameters of BBB carrier-mediated transport (CMT) systems, or for the determination of dissociation constants of peptide binding to BBB receptor-mediated transport (RMT) systems expressed at either the animal or the human BBB. This review will discuss how the isolated brain microvessel model system has advanced our understanding of the organization and functional properties of the BBB, and highlight recent renewed interest in this 50 year old model of the BBB.
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Affiliation(s)
- William M Pardridge
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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Lu X, Moeini M, Li B, Lu Y, Damseh R, Pouliot P, Thorin É, Lesage F. A Pilot Study Investigating Changes in Capillary Hemodynamics and Its Modulation by Exercise in the APP-PS1 Alzheimer Mouse Model. Front Neurosci 2019; 13:1261. [PMID: 31920472 PMCID: PMC6915102 DOI: 10.3389/fnins.2019.01261] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 11/06/2019] [Indexed: 12/11/2022] Open
Abstract
Dysfunction in neurovascular coupling that results in a mismatch between cerebral blood flow and neuronal activity has been suggested to play a key role in the pathogenesis of Alzheimer's disease (AD). Meanwhile, physical exercise is a powerful approach for maintaining cognitive health and could play a preventive role against the progression of AD. Given the fundamental role of capillaries in oxygen transport to tissue, our pilot study aimed to characterize changes in capillary hemodynamics with AD and AD supplemented by exercise. Exploiting two-photon microscopy, intrinsic signal optical imaging, and magnetic resonance imaging, we found hemodynamic alterations and lower vascular density with AD that were reversed by exercise. We further observed that capillary properties were branch order-dependent and that stimulation-evoked changes were attenuated with AD but increased by exercise. Our study provides novel indications into cerebral microcirculatory disturbances with AD and the modulating role of voluntary exercise on these alterations.
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Affiliation(s)
- Xuecong Lu
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Mohammad Moeini
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
| | - Yuankang Lu
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Rafat Damseh
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Philippe Pouliot
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
| | - Éric Thorin
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
- Department of Surgery, Faculty of Medicine, Université de Montréal, Montreal, QC, Canada
| | - Frédéric Lesage
- Biomedical Engineering Institute, École Polytechnique de Montréal, Montreal, QC, Canada
- Montreal Heart Institute, Research Center, Montreal, QC, Canada
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Lu Y, Zhang C, Lu X, Moeini M, Thorin E, Lesage F. Impact of atherosclerotic disease on cerebral microvasculature and tissue oxygenation in awake LDLR-/-hApoB+/+ transgenic mice. NEUROPHOTONICS 2019; 6:045003. [PMID: 31673566 PMCID: PMC6811703 DOI: 10.1117/1.nph.6.4.045003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/17/2019] [Indexed: 05/17/2023]
Abstract
We explore cortical microvasculature changes during the progression of atherosclerosis using young and old transgenic atherosclerotic (ATX) mice with thinned-skull cranial window. In awake animals, exploiting intrinsic signal optical imaging, Doppler optical coherence tomography, and two-photon microscopy, we investigate how the progression of atherosclerotic disease affects the morphology and function of cortical microvasculature as well as baseline cerebral tissue oxygenation. Results show that aged ATX mice exhibited weaker hemodynamic response in the somatosensory cortex to whisker stimulation and that the diameter of their descending arterioles and associated mean blood flow decreased significantly compared with the young ATX group. Data from two-photon phosphorescence lifetime microscopy indicate that old ATX mice had lower and more heterogeneous partial pressure of oxygen ( PO 2 ) in cortical tissue than young ATX mice. In addition, hypoxic micropockets in cortical tissue were found in old, but not young, ATX mice. Capillary red blood cell (RBC) flux, RBC velocity, RBC velocity heterogeneity, hematocrit, and diameter were also measured using line scans with two-photon fluorescence microscopy. When compared with the young group, RBC flux, velocity, and hematocrit decreased and RBC velocity heterogeneity increased in old ATX mice, presumably due to disturbed blood supply from arterioles that were affected by atherosclerosis. Finally, dilation of capillaries in old ATX mice was observed, which suggests that capillaries play an active role in compensating for an oxygen deficit in brain tissue.
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Affiliation(s)
- Yuankang Lu
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
| | - Cong Zhang
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
| | - Xuecong Lu
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
| | - Mohammad Moeini
- Amirkabir University of Technology (Tehran Polytechnic), Biomedical Engineering Department, Tehran, Iran
| | - Eric Thorin
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
- Université de Montréal, Department of Pharmacology and Physiology, Faculty of Medicine, Montréal, Québec, Canada
| | - Frédéric Lesage
- École Polytechnique de Montréal, Laboratoire d’Imagerie optique et moléculaire, Montréal, Québec, Canada
- Institut de Cardiologie de Montréal, Montréal, Québec, Canada
- Address all correspondence to Frédéric Lesage, E-mail:
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15
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Michelson NJ, Vanni MP, Murphy TH. Comparison between transgenic and AAV-PHP.eB-mediated expression of GCaMP6s using in vivo wide-field functional imaging of brain activity. NEUROPHOTONICS 2019; 6:025014. [PMID: 31763351 PMCID: PMC6864505 DOI: 10.1117/1.nph.6.2.025014] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/22/2019] [Indexed: 05/13/2023]
Abstract
We employ transcranial wide-field single-photon imaging to compare genetically encoded calcium sensors under transgenic or viral vector expression strategies. Awake, head-fixed animals and brief visual flash stimuli are used to assess function. The use of awake transcranial imaging may reduce confounds attributed to cranial window implantation or anesthesia states. We report differences in wide-field epifluorescence brightness and peak Δ F / F 0 response to visual stimulation between expression strategies. Other metrics for indicator performance include fluctuation analysis (standard deviation) and regional correlation maps made from spontaneous activity. We suggest that multiple measures, such as stimulus-evoked signal-to-noise ratio, brightness, and averaged visual Δ F / F 0 response, may be necessary to characterize indicator sensitivity and methods of expression. Furthermore, we show that strategies using blood brain barrier-permeable viruses, such as PHP.eB, yield comparable expression and function as those derived from transgenic mice. We suggest that testing of new genetically engineered activity sensors could employ a single-photon, wide-field imaging pipeline involving visual stimulation in awake mice that have been intravenously injected with PHP.eB.
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Affiliation(s)
- Nicholas J. Michelson
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
| | - Matthieu P. Vanni
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Université de Montréal, School of Optometry, Montréal, Québec, Canada
| | - Timothy H. Murphy
- Kinsmen Laboratory of Neurological Research, Department of Psychiatry, Vancouver, British Columbia, Canada
- University of British Columbia, Djavad Mowafaghian Centre for Brain Health, Vancouver, British Columbia, Canada
- Address all correspondence to Timothy H. Murphy E-mail:
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Masamoto K, Vazquez A. Optical imaging and modulation of neurovascular responses. J Cereb Blood Flow Metab 2018; 38:2057-2072. [PMID: 30334644 PMCID: PMC6282226 DOI: 10.1177/0271678x18803372] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/02/2018] [Indexed: 12/17/2022]
Abstract
The cerebral microvasculature consists of pial vascular networks, parenchymal descending arterioles, ascending venules and parenchymal capillaries. This vascular compartmentalization is vital to precisely deliver blood to balance continuously varying neural demands in multiple brain regions. Optical imaging techniques have facilitated the investigation of dynamic spatial and temporal properties of microvascular functions in real time. Their combination with transgenic animal models encoding specific genetic targets have further strengthened the importance of optical methods for neurovascular research by allowing for the modulation and monitoring of neuro vascular function. Image analysis methods with three-dimensional reconstruction are also helping to understand the complexity of microscopic observations. Here, we review the compartmentalized cerebral microvascular responses to global perturbations as well as regional changes in response to neural activity to highlight the differences in vascular action sites. In addition, microvascular responses elicited by optical modulation of different cell-type targets are summarized with emphasis on variable spatiotemporal dynamics of microvascular responses. Finally, long-term changes in microvascular compartmentalization are discussed to help understand potential relationships between CBF disturbances and the development of neurodegenerative diseases and cognitive decline.
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Affiliation(s)
- Kazuto Masamoto
- Faculty of Informatics and Engineering, University of Electro-Communications, Tokyo, Japan
- Brain Science Inspired Life Support Research Center, University of Electro-Communications, Tokyo, Japan
| | - Alberto Vazquez
- Departments of Radiology and Bioengineering, University of Pittsburgh, PA, USA
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Koide M, Moshkforoush A, Tsoukias NM, Hill-Eubanks DC, Wellman GC, Nelson MT, Dabertrand F. The yin and yang of K V channels in cerebral small vessel pathologies. Microcirculation 2018; 25. [PMID: 29247493 DOI: 10.1111/micc.12436] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
Cerebral SVDs encompass a group of genetic and sporadic pathological processes leading to brain lesions, cognitive decline, and stroke. There is no specific treatment for SVDs, which progress silently for years before becoming clinically symptomatic. Here, we examine parallels in the functional defects of PAs in CADASIL, a monogenic form of SVD, and in response to SAH, a common type of hemorrhagic stroke that also targets the brain microvasculature. Both animal models exhibit dysregulation of the voltage-gated potassium channel, KV 1, in arteriolar myocytes, an impairment that compromises responses to vasoactive stimuli and impacts CBF autoregulation and local dilatory responses to neuronal activity (NVC). However, the extent to which this channelopathy-like defect ultimately contributes to these pathologies is unknown. Combining experimental data with computational modeling, we describe the role of KV 1 channels in the regulation of myocyte membrane potential at rest and during the modest increase in extracellular potassium associated with NVC. We conclude that PA resting membrane potential and myogenic tone depend strongly on KV 1.2/1.5 channel density, and that reciprocal changes in KV channel density in CADASIL and SAH produce opposite effects on extracellular potassium-mediated dilation during NVC.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Arash Moshkforoush
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | | | - George C Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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