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Yang C, Dong W, Luo J, Ma M, Gao Y, Ni L, Liu H, Cha C, Xiao Y, Huang S. The Median Effective Dose of Intrathecal Hyperbaric Bupivacaine for Cesarean Section at Moderately High-Altitude. Drug Des Devel Ther 2024; 18:1313-1319. [PMID: 38681209 PMCID: PMC11048353 DOI: 10.2147/dddt.s455844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 04/16/2024] [Indexed: 05/01/2024] Open
Abstract
Objective Alterations in altitude can lead to an augmented requirement for local anesthesia among patients. Nevertheless, the necessity for an elevated dosage of local anesthetic for parturients at moderately high altitudes during spinal anesthesia for cesarean section remains uninvestigated. This up-down sequential study endeavors to determine the ED50 dose of bupivacaine required for spinal anesthesia during cesarean sections at moderately high-altitude. Methods Thirty singleton parturients at moderately high altitude underwent elective cesarean section under combined spinal-epidural anesthesia. The up-and-down sequential method was employed, starting with an initial dose of 12mg (1.6mL) of 0.75% hyperbaric bupivacaine for the first participant. The dose for the next case was adjusted up or down by 0.75mg based on the effectiveness of the previous participant. Effectiveness was defined as the bilateral sensory block reaching T6 within 15 minutes after spinal anesthesia injection, without the need for additional epidural anesthesia before fetal delivery. The ED50 dose and 95% confidence interval were calculated using the Dixon sequential method and isotonic regression, respectively. The incidence of maternal hypotension, nausea, and vomiting during the study period was also recorded. Results The ED50 of hyperbaric bupivacaine for spinal anesthesia in cesarean section was calculated as 8.23 mg (95% CI, 6.52-9.32 mg) using the Dixon up-and-down method. Further validation using isotonic regression yielded a value of 8.39 mg (95% CI, 7.48-9.30 mg), confirming the accuracy and sensitivity of the conclusion. During the operation, only 6 parturients experienced hypotension, and no adverse reactions such as nausea, vomiting, and shivering were observed. Conclusion The ED50 dose of 0.75% hyperbaric bupivacaine for spinal anesthesia during cesarean section at moderately high altitude is 8.23 mg, which exceeds the ED50 dose typically required by parturients at low altitude. Comprehensive investigations are warranted to ascertain the ED90 or ED95 dose of local anesthetics for cesarean section at moderately high altitudes, thereby offering enhanced guidance for clinical practice.
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Affiliation(s)
- Chen Yang
- Department of Anesthesia, Obstetrics & Gynecology Hospital, Fudan University, Shanghai, People’s Republic of China
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Wangjun Dong
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Jianbo Luo
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Mengzhao Ma
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Yeyue Gao
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Lijie Ni
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Huixing Liu
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Chengjun Cha
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Yangli Xiao
- Department of Anesthesia, Yongping County People’s Hospital, Yunnan, People’s Republic of China
| | - Shaoqiang Huang
- Department of Anesthesia, Obstetrics & Gynecology Hospital, Fudan University, Shanghai, People’s Republic of China
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2
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Ji X, Bao B, Li LZ, Pu J, Lin Y, Zhang X, Chen Z, Li T. EEG and fNIRS datasets based on Stroop task during two weeks of high-altitude exposure in new immigrants. Sci Data 2024; 11:350. [PMID: 38589476 PMCID: PMC11001964 DOI: 10.1038/s41597-024-03200-8] [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: 01/23/2024] [Accepted: 03/28/2024] [Indexed: 04/10/2024] Open
Abstract
Maintaining sufficient cerebral oxygen metabolism is crucial for human survival, especially in challenging conditions such as high-altitudes. Human cognitive neural activity is sensitive to fluctuations in oxygen levels. However, there is a lack of publicly available datasets on human behavioural responses and cerebral dynamics assessments during the execution of conflicting tasks in natural hypoxic environments. We recruited 80 healthy new immigrant volunteers (males, aged 20 ± 2 years) and employed the Stroop cognitive conflict paradigm. After a two-week exposure to both high and low-altitudes, the behavioural performance, prefrontal oxygen levels, and electroencephalography (EEG) signals were recorded. Comparative analyses were conducted on the behavioural reaction times and accuracy during Stroop tasks, and statistical analyses of participants' prefrontal oxygen levels and EEG signals were performed. We anticipate that our open-access dataset will contribute to the development of monitoring devices and algorithms, designed specifically for measuring cerebral oxygen and EEG dynamics in populations exposed to extreme environments, particularly among individuals suffering from oxygen deficiency.
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Affiliation(s)
- Xiang Ji
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Botao Bao
- School of optoelectronic science and engineering, University of Electronic Science & Technology of China, Chengdu, China
| | - Lin Z Li
- Britton Chance Laboratory of Redox Imaging and Laboratory of Molecular Imaging, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiangbo Pu
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Yu Lin
- The Estee Lauder Companies, Melville, NY, USA
| | - Xin Zhang
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Zemeng Chen
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China
| | - Ting Li
- Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
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3
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Liu Y, Yuan F, Peng Z, Zhan Y, Lin J, Zhang R, Zhang J. Decrease in Cerebral Blood Flow after Reoxygenation Is Associated with Neurological Syndrome Sequelae and Blood Pressure. Brain Sci 2023; 13:1600. [PMID: 38002559 PMCID: PMC10669967 DOI: 10.3390/brainsci13111600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 10/30/2023] [Accepted: 11/06/2023] [Indexed: 11/26/2023] Open
Abstract
Changes in cerebral blood flow (CBF) and regulation of cerebral circulation occur at high altitude (HA). However, the changes in CBF and their associations with neurological syndrome sequelae and blood pressure after subjects return to the lowlands remain unclear. In this study, the subjects were 23 college students who were teaching at an altitude of 4300 m for 30 days. These subjects were studied before reaching the HA (Test 1), one week after returning to the lowlands (Test 2), and three months after returning to the lowlands (Test 3). Symptom scores for de-acclimatization syndrome were evaluated. Changes in CBF were measured using the magnetic resonance imaging arterial spin labeling (ASL) technique. Additionally, the velocity of CBF in the cerebral arteries was measured using a transcranial doppler (TCD). In Test 2 vs. Test 1, the peak systolic velocity and mean velocity in the basilar artery were significantly decreased. CBF exhibited significant decreases in the left putamen/cerebellum crus1/vermis and right thalamus/inferior temporal gyrus, while significant increases were observed in the left postcentral gyrus/precuneus and right middle cingulate gyrus/superior frontal gyrus. In Test 3 vs. Test 1, the basilar artery velocity returned to the baseline level, while CBF continued to decrease. The mean global CBF showed a decreasing trend from Test 1 to Test 3. Furthermore, the mean global CBF had a negative correlation with the systolic pressure, pulse pressure, and mean arterial pressure. The decrease in CBF after reoxygenation may underlie the neurological symptoms in subjects returning to the lowlands. Increased blood pressure could serve as a predictor of a decrease in CBF.
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Affiliation(s)
- Yanqiu Liu
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Fengjuan Yuan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Zhongwei Peng
- Department of Neurology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Yadong Zhan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jianzhong Lin
- Department of Radiology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China
| | - Ran Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Xiamen University, Xiamen 361102, China
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4
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Hutcheon EA, Vakorin VA, Nunes AS, Ribary U, Ferguson S, Claydon VE, Doesburg SM. Comparing neuronal oscillations during visual spatial attention orienting between normobaric and hypobaric hypoxia. Sci Rep 2023; 13:18021. [PMID: 37865721 PMCID: PMC10590435 DOI: 10.1038/s41598-023-45308-8] [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: 05/27/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023] Open
Abstract
Normobaric hypoxia (NH) and hypobaric hypoxia (HH) are both used to train aircraft pilots to recognize symptoms of hypoxia. NH (low oxygen concentration) training is often preferred because it is more cost effective, simpler, and safer than HH. It is unclear, however, whether NH is neurophysiologically equivalent to HH (high altitude). Previous studies have shown that neural oscillations, particularly those in the alpha band (8-12 Hz), are impacted by hypoxia. Attention tasks have been shown to reliably modulate alpha oscillations, although the neurophysiological impacts of hypoxia during cognitive processing remains poorly understood. To address this we investigated induced and evoked power alongside physiological data while participants performed an attention task during control (normobaric normoxia or NN), NH (fraction of inspired oxygen = 12.8%, partial pressure of inspired oxygen = 87.2 mmHg), and HH (3962 m, partial pressure of inspired oxygen = 87.2 mmHg) conditions inside a hypobaric chamber. No significant differences between NH and HH were found in oxygen saturation, end tidal gases, breathing rate, middle cerebral artery velocity and blood pressure. Induced alpha power was significantly decreased in NH and HH when compared to NN. Participants in the HH condition showed significantly increased induced lower-beta power and evoked higher-beta power, compared with the NH and NN conditions, indicating that NH and HH differ in their impact on neurophysiological activity supporting cognition. NH and HH were found not to be neurophysiologically equivalent as electroencephalography was able to differentiate NH from HH.
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Affiliation(s)
- Evan A Hutcheon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada.
| | - Vasily A Vakorin
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Adonay S Nunes
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, USA
| | - Urs Ribary
- Department of Psychology, Simon Fraser University, Burnaby, BC, Canada
| | - Sherri Ferguson
- Environmental Physiology and Medicine Unit, Faculty of Science, Simon Fraser University, Burnaby, BC, Canada
| | - Victoria E Claydon
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
| | - Sam M Doesburg
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Institute for Neuroscience and Neurotechnology, Simon Fraser University, Burnaby, Canada
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5
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Song R, Tao G, Guo F, Ma H, Zhang J, Wang Y. The change of attention network functions and physiological adaptation during high-altitude hypoxia and reoxygenation. Physiol Behav 2023; 268:114240. [PMID: 37201691 DOI: 10.1016/j.physbeh.2023.114240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 04/09/2023] [Accepted: 05/15/2023] [Indexed: 05/20/2023]
Abstract
Previous studies have not reached a definitive conclusion regarding the effect of high-altitude hypoxia and reoxygenation on attention. To clarify the influence of altitude and exposure time on attention and the relations between physiological activity and attention, we conducted a longitudinal study to track attention network functions in 26 college students. The scores on the attention network test and physiological data, including heart rate, percutaneous arterial oxygen saturation (SpO2), blood pressure, and vital capacity in pulmonary function measurement, were collected at five time-points: two weeks before arriving at high altitude (baseline), within 3 days after arriving at high altitude (HA3), 21 days after arriving at high altitude (HA21), 7 days after returning to sea level (POST7) and 30 days after returning to sea level (POST30). The alerting scores at POST30 were significantly higher than those at baseline, HA3 and HA21; the orienting scores at HA3 were lower than those at POST7 and POST30; the executive control scores at POST7 were significantly lower than those at baseline, HA3, HA21, and POST30; and the executive control scores at HA3 were significantly higher than those at POST30. The change in SpO2 during high-altitude acclimatization (from HA3 to HA21) was positively correlated with the orienting score at HA21. Vital capacity changes during acute deacclimatization positively correlated with orienting scores at POST7. Attention network functions at the behavioral level did not decline after acute hypoxia exposure compared with baseline. Attention network functions after returning to sea level were improved compared with those during acute hypoxia; additionally, alerting and executive function scores were improved compared with those at baseline. Thus, the speed of physiological adaptation could facilitate the recovery of orienting function during acclimatization and deacclimatization.
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Affiliation(s)
- Rui Song
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Getong Tao
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Fumei Guo
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Hailin Ma
- Plateau Brain Science Research Center, Tibet University/South China Normal University, Guangzhou/Tibet, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, China
| | - Yan Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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6
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Cui J, Ma Q, Zhang C, Li Y, Liu J, Xie K, Luo E, Zhai M, Tang C. Keratin 18 Depletion as a Possible Mechanism for the Induction of Apoptosis and Ferroptosis in the Rat Hippocampus After Hypobaric Hypoxia. Neuroscience 2023; 513:64-75. [PMID: 36395917 DOI: 10.1016/j.neuroscience.2022.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/03/2022] [Accepted: 11/08/2022] [Indexed: 11/16/2022]
Abstract
Memory impairment is one of the neuropsychological effects of hypobaric hypoxia (HH), which can be associated with programmed cell death, such as apoptosis and ferroptosis. Emerging evidence indicates crosstalk between apoptosis and ferroptosis, while the crosstalk between HH-induced apoptosis and ferroptosis in the hippocampus has not been clarified. Here, microarray profiles were extracted to analyze the differentially expressed genes with and without HH exposure, and keratin 18 (Krt18) was found to be a potential gene related to both apoptosis and ferroptosis. Then, we conducted morphological observations that showed that apoptosis and ferroptosis coexisted in the rat hippocampus after HH exposure. Combined with the real-time q-PCR analysis, the mRNA expression of Krt18 decreased significantly after HH exposure for 1 day and 3 days, and Mapk10 (JNK3) was upregulated at the corresponding time points. After exposure for 7 days, Krt18 and JNK3 showed no significant change. In conclusion, Krt18 may regulate apoptosis and ferroptosis simultaneously, possibly via the JNK signaling pathway, which might provide a potential central target for apoptosis and ferroptosis in hippocampal injury after HH exposure.
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Affiliation(s)
- Jinxiu Cui
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Qianqian Ma
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China; The College of Life Sciences, Northwest University, 710069 Xi'an, Shaanxi, PR China
| | - Chenxu Zhang
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Yuanzhe Li
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Juan Liu
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Kangning Xie
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Erping Luo
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China
| | - Mingming Zhai
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China.
| | - Chi Tang
- Department of Military Medical Equipment and Metrology, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China; Shaanxi Provincial Key Laboratory of Bioelectromagnetic Detection and Intelligent Perception, School of Military Biomedical Engineering, Fourth Military Medical University, 710032 Xi'an, Shaanxi, PR China.
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7
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Acute Hypobaric Hypoxia Exposure Causes Neurobehavioral Impairments in Rats: Role of Brain Catecholamines and Tetrahydrobiopterin Alterations. Neurochem Res 2023; 48:471-486. [PMID: 36205808 DOI: 10.1007/s11064-022-03767-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/12/2022] [Accepted: 09/22/2022] [Indexed: 02/07/2023]
Abstract
Hypoxia is a state in which the body or a specific part of the body is deprived of adequate oxygen supply at the tissue level. Sojourners involved in different activities at high altitudes (> 2500 m) face hypobaric hypoxia (HH) due to low oxygen in the atmosphere. HH is an example of generalized hypoxia, where the homeostasis of the entire body of an organism is affected and results in neurochemical changes. It is known that lower O2 levels affect catecholamines (CA), severely impairing cognitive and locomotor behavior. However, there is less evidence on the effect of HH-mediated alteration in brain Tetrahydrobiopterin (BH4) levels and its role in neurobehavioral impairments. Hence, this study aimed to shed light on the effect of acute HH on CA and BH4 levels with its neurobehavioral impact on Wistar rat models. After HH exposure, significant alteration of the CA levels in the discrete brain regions, viz., frontal cortex, hippocampus, midbrain, and cerebellum was observed. HH exposure significantly reduced spontaneous motor activity, motor coordination, and spatial memory. The present study suggests that the HH-induced behavioral changes might be related to the alteration of the expression pattern of CA and BH4-related genes and proteins in different rat brain regions. Overall, this study provides novel insights into the role of BH4 and CA in HH-induced neurobehavioral impairments.
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8
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Burtscher J, Niedermeier M, Hüfner K, van den Burg E, Kopp M, Stoop R, Burtscher M, Gatterer H, Millet GP. The interplay of hypoxic and mental stress: Implications for anxiety and depressive disorders. Neurosci Biobehav Rev 2022; 138:104718. [PMID: 35661753 DOI: 10.1016/j.neubiorev.2022.104718] [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] [Received: 04/07/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 12/14/2022]
Abstract
Adequate oxygen supply is essential for the human brain to meet its high energy demands. Therefore, elaborate molecular and systemic mechanism are in place to enable adaptation to low oxygen availability. Anxiety and depressive disorders are characterized by alterations in brain oxygen metabolism and of its components, such as mitochondria or hypoxia inducible factor (HIF)-pathways. Conversely, sensitivity and tolerance to hypoxia may depend on parameters of mental stress and the severity of anxiety and depressive disorders. Here we discuss relevant mechanisms of adaptations to hypoxia, as well as their involvement in mental stress and the etiopathogenesis of anxiety and depressive disorders. We suggest that mechanisms of adaptations to hypoxia (including metabolic responses, inflammation, and the activation of chemosensitive brain regions) modulate and are modulated by stress-related pathways and associated psychiatric diseases. While severe chronic hypoxia or dysfunctional hypoxia adaptations can contribute to the pathogenesis of anxiety and depressive disorders, harnessing controlled responses to hypoxia to increase cellular and psychological resilience emerges as a novel treatment strategy for these diseases.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland.
| | - Martin Niedermeier
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Katharina Hüfner
- Department of Psychiatry, Psychotherapy, Psychosomatics and Medical Psychology, University Clinic for Psychiatry II, Innsbruck Medical University, Innsbruck, Austria
| | - Erwin van den Burg
- Department of Psychiatry, Center of Psychiatric Neuroscience (CNP), University Hospital of Lausanne (CHUV), Prilly, Lausanne, Switzerland
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Ron Stoop
- Department of Psychiatry, Center of Psychiatric Neuroscience (CNP), University Hospital of Lausanne (CHUV), Prilly, Lausanne, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Hannes Gatterer
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland; Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
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9
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Dynamic cerebral blood flow changes with FOXOs stimulation are involved in neuronal damage associated with high-altitude cerebral edema in mice. Brain Res 2022; 1790:147987. [PMID: 35724762 DOI: 10.1016/j.brainres.2022.147987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 05/21/2022] [Accepted: 06/14/2022] [Indexed: 11/22/2022]
Abstract
Acute hypobaric hypoxia (AHH) exposure causes altitude mountain sickness (AMS) and life-threatening high altitude cerebral edema (HACE). Despite decades of research, the role of cerebral blood flow (CBF) changes in the pathophysiology of severe AMS remains unclear. The current study evaluated spatiotemporal responses of CBF associated with HACE in mice during the early stages of ascent to high altitudes. First, mice were exposed to AHH to test their tolerance to increasing altitudes (3000-8000 m). Because of its significant influence on both locomotor activity and rotarod behavior tests in mice, further observations were initiated at an altitude of 6000 m to investigate the specific pathophysiology of AMS. Compared with controls, laser speckle contrast imaging (LSCI) revealed a significant decrease in CBF during the early stage (0.5-24 h) at an altitude of 6000 m that was accompanied by a significant increase in brain water content (BWC). Moreover, observations of brain lipid oxidative damage and oxidative stress during the early stage of AHH exposure revealed DNA and cellular damage in cortical and hippocampal regions. Transcriptome profiling of the hippocampus revealed upregulation of forkhead box transcription factors. Similarly, western blot assays revealed upregulation of FOXO1a, FOXO3a, caspase-3 and Bax, and downregulation of Bcl-2, indicating a temporal influence of AHH on mitochondrial function and neuronal apoptosis. Thus, we found that the pathophysiology of HACE occurred with dynamic CBF changes, which triggered oxidative stress and neuronal damage in the mouse brain after AHH exposure. Our findings provide potential strategies for treatment of AHH in the future.
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10
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Yeung MK, Chu VW. Viewing neurovascular coupling through the lens of combined EEG-fNIRS: A systematic review of current methods. Psychophysiology 2022; 59:e14054. [PMID: 35357703 DOI: 10.1111/psyp.14054] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 02/01/2022] [Accepted: 03/08/2022] [Indexed: 12/25/2022]
Abstract
Neurovascular coupling is a key physiological mechanism that occurs in the healthy human brain, and understanding this process has implications for understanding the aging and neuropsychiatric populations. Combined electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) has emerged as a promising, noninvasive tool for probing neurovascular interactions in humans. However, the utility of this approach critically depends on the methodological quality used for multimodal integration. Despite a growing number of combined EEG-fNIRS applications reported in recent years, the methodological rigor of past studies remains unclear, limiting the accurate interpretation of reported findings and hindering the translational application of this multimodal approach. To fill this knowledge gap, we critically evaluated various methodological aspects of previous combined EEG-fNIRS studies performed in healthy individuals. A literature search was conducted using PubMed and PsycINFO on June 28, 2021. Studies involving concurrent EEG and fNIRS measurements in awake and healthy individuals were selected. After screening and eligibility assessment, 96 studies were included in the methodological evaluation. Specifically, we critically reviewed various aspects of participant sampling, experimental design, signal acquisition, data preprocessing, outcome selection, data analysis, and results presentation reported in these studies. Altogether, we identified several notable strengths and limitations of the existing EEG-fNIRS literature. In light of these limitations and the features of combined EEG-fNIRS, recommendations are made to improve and standardize research practices to facilitate the use of combined EEG-fNIRS when studying healthy neurovascular coupling processes and alterations in neurovascular coupling among various populations.
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Affiliation(s)
- Michael K Yeung
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China
| | - Vivian W Chu
- Department of Rehabilitation Sciences, The Hong Kong Polytechnic University, Hong Kong, China
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11
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Talks BJ, Campbell C, Larcombe SJ, Marlow L, Finnegan SL, Lewis CT, Lucas SJE, Harrison OK, Pattinson KTS. Baseline Psychological Traits Contribute to Lake Louise Acute Mountain Sickness Score at High Altitude. High Alt Med Biol 2022; 23:69-77. [PMID: 35353609 PMCID: PMC8982137 DOI: 10.1089/ham.2021.0073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Talks, Benjamin James, Catherine Campbell, Stephanie J. Larcombe, Lucy Marlow, Sarah L. Finnegan, Christopher T. Lewis, Samuel J.E. Lucas, Olivia K. Harrison, and Kyle T.S. Pattinson. Baseline psychological traits contribute to Lake Louise Acute Mountain Sickness score at high altitude. High Alt Med Biol. 23:69-77, 2022. Background: Interoception refers to an individual's ability to sense their internal bodily sensations. Acute mountain sickness (AMS) is a common feature of ascent to high altitude that is only partially explained by measures of peripheral physiology. We hypothesized that interoceptive ability may explain the disconnect between measures of physiology and symptom experience in AMS. Methods: Two groups of 18 participants were recruited to complete a respiratory interoceptive task three times at 2-week intervals. The control group remained in Birmingham (140 m altitude) for all three tests. The altitude group completed test 1 in Birmingham, test 2 the day after arrival at 2,624 m, and test 3 at 2,728 m after an 11-day trek at high altitude (up to 4,800 m). Results: By measuring changes to metacognitive performance, we showed that acute ascent to altitude neither presented an interoceptive challenge, nor acted as interoceptive training. However, AMS symptom burden throughout the trek was found to relate to sea level measures of anxiety, agoraphobia, and neuroticism. Conclusions: This suggests that the Lake Louise AMS score is not solely a reflection of physiological changes on ascent to high altitude, despite often being used as such by researchers and commercial trekking companies alike.
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Affiliation(s)
- Benjamin James Talks
- Population Health Sciences Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom.,Birmingham Medical Research Expeditionary Society, Birmingham, United Kingdom
| | - Catherine Campbell
- Population Health Sciences Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Stephanie J Larcombe
- Birmingham Medical Research Expeditionary Society, Birmingham, United Kingdom.,Medical School, University of Birmingham, Birmingham, United Kingdom
| | - Lucy Marlow
- Warwick Medical School, Warwick University, Coventry, United Kingdom.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Sarah L Finnegan
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Christopher T Lewis
- Birmingham Medical Research Expeditionary Society, Birmingham, United Kingdom.,Department of Anesthesia, Ysbyty Gwynedd, Bangor, United Kingdom
| | - Samuel J E Lucas
- Birmingham Medical Research Expeditionary Society, Birmingham, United Kingdom.,School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Olivia K Harrison
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Translational Neuromodeling Unit, Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, Switzerland.,School of Pharmacy, University of Otago, Dunedin, New Zealand
| | - Kyle T S Pattinson
- Birmingham Medical Research Expeditionary Society, Birmingham, United Kingdom.,Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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12
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Keough JRG, Cates VC, Tymko MM, Boulet LM, Jamieson AN, Foster GE, Day TA. Regional differences in cerebrovascular reactivity in response to acute isocapnic hypoxia in healthy humans: Methodological considerations. Respir Physiol Neurobiol 2021; 294:103770. [PMID: 34343693 DOI: 10.1016/j.resp.2021.103770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 07/15/2021] [Accepted: 07/29/2021] [Indexed: 11/30/2022]
Abstract
The cerebrovasculature responds to blood gas challenges. Regional differences (anterior vs. posterior) in cerebrovascular responses to increases in CO2 have been extensively studied. However, regional cerebrovascular reactivity (CVR) responses to low O2 (hypoxia) are equivocal, likely due to differences in analysis. We assessed the effects of acute isocapnic hypoxia on regional CVR comparing absolute and relative (%-change) responses in the middle cerebral artery (MCA) and posterior cerebral artery (PCA). We instrumented 14 healthy participants with a transcranial Doppler ultrasound (cerebral blood velocity), finometer (beat-by-beat blood pressure), dual gas analyzer (end-tidal CO2 and O2), and utilized a dynamic end-tidal forcing system to elicit a single 5-min bout of isocapnic hypoxia (∼45 Torr PETO2, ∼80 % SpO2). During exposure to acute hypoxia, absolute responses were larger in the anterior compared to posterior cerebral circulation (P < 0.001), but were not different when comparing relative responses (P = 0.45). Consistent reporting of CVR to hypoxia will aid understanding normative responses, particularly in assessing populations with impaired cerebrovascular function.
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Affiliation(s)
- Joanna R G Keough
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Valerie C Cates
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Michael M Tymko
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada; Faculty of Kinesiology, Sport and Recreation, University of Alberta, Edmonton, Alberta, Canada
| | - Lindsey M Boulet
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada; Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Alenna N Jamieson
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada
| | - Glen E Foster
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, Alberta, Canada.
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13
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Burtscher J, Mallet RT, Burtscher M, Millet GP. Hypoxia and brain aging: Neurodegeneration or neuroprotection? Ageing Res Rev 2021; 68:101343. [PMID: 33862277 DOI: 10.1016/j.arr.2021.101343] [Citation(s) in RCA: 100] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 12/12/2022]
Abstract
The absolute reliance of the mammalian brain on oxygen to generate ATP renders it acutely vulnerable to hypoxia, whether at high altitude or in clinical settings of anemia or pulmonary disease. Hypoxia is pivotal to the pathogeneses of myriad neurological disorders, including Alzheimer's, Parkinson's and other age-related neurodegenerative diseases. Conversely, reduced environmental oxygen, e.g. sojourns or residing at high altitudes, may impart favorable effects on aging and mortality. Moreover, controlled hypoxia exposure may represent a treatment strategy for age-related neurological disorders. This review discusses evidence of hypoxia's beneficial vs. detrimental impacts on the aging brain and the molecular mechanisms that mediate these divergent effects. It draws upon an extensive literature search on the effects of hypoxia/altitude on brain aging, and detailed analysis of all identified studies directly comparing brain responses to hypoxia in young vs. aged humans or rodents. Special attention is directed toward the risks vs. benefits of hypoxia exposure to the elderly, and potential therapeutic applications of hypoxia for neurodegenerative diseases. Finally, important questions for future research are discussed.
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Affiliation(s)
- Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland; Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland.
| | - Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX 76107, USA
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, Austria
| | - Grégoire P Millet
- Institute of Sport Sciences, University of Lausanne, CH-1015, Lausanne, Switzerland
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14
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Mallet RT, Burtscher J, Richalet JP, Millet GP, Burtscher M. Impact of High Altitude on Cardiovascular Health: Current Perspectives. Vasc Health Risk Manag 2021; 17:317-335. [PMID: 34135590 PMCID: PMC8197622 DOI: 10.2147/vhrm.s294121] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Globally, about 400 million people reside at terrestrial altitudes above 1500 m, and more than 100 million lowlanders visit mountainous areas above 2500 m annually. The interactions between the low barometric pressure and partial pressure of O2, climate, individual genetic, lifestyle and socio-economic factors, as well as adaptation and acclimatization processes at high elevations are extremely complex. It is challenging to decipher the effects of these myriad factors on the cardiovascular health in high altitude residents, and even more so in those ascending to high altitudes with or without preexisting diseases. This review aims to interpret epidemiological observations in high-altitude populations; present and discuss cardiovascular responses to acute and subacute high-altitude exposure in general and more specifically in people with preexisting cardiovascular diseases; the relations between cardiovascular pathologies and neurodegenerative diseases at altitude; the effects of high-altitude exercise; and the putative cardioprotective mechanisms of hypobaric hypoxia.
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Affiliation(s)
- Robert T Mallet
- Department of Physiology and Anatomy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Johannes Burtscher
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Jean-Paul Richalet
- Laboratoire Hypoxie & Poumon, UMR Inserm U1272, Université Sorbonne Paris Nord 13, Bobigny Cedex, F-93017, France
| | - Gregoire P Millet
- Department of Biomedical Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
- Institute of Sport Sciences, University of Lausanne, Lausanne, CH-1015, Switzerland
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, Innsbruck, A-6020, Austria
- Austrian Society for Alpine and High-Altitude Medicine, Mieming, Austria
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15
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Barclay H, Mukerji S, Kayser B, O'Donnell T, Tzeng YC, Hill S, Knapp K, Legg S, Frei D, Fan JL. Respiratory alkalinization and posterior cerebral artery dilatation predict acute mountain sickness severity during 10 h normobaric hypoxia. Exp Physiol 2020; 106:175-190. [PMID: 33347666 DOI: 10.1113/ep088938] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022]
Abstract
NEW FINDINGS What is the central question of this study? The pathophysiology of acute mountain sickness (AMS), involving the respiratory, renal and cerebrovascular systems, remains poorly understood. How do the early adaptations in these systems during a simulated altitude of 5000 m relate to AMS risk? What is the main finding and its importance? The rate of blood alkalosis and cerebral artery dilatation predict AMS severity during the first 10 h of exposure to a simulated altitude of 5000 m. Slow metabolic compensation by the kidneys of respiratory alkalosis attributable to a brisk breathing response together with excessive brain blood vessel dilatation might be involved in early development of AMS. ABSTRACT The complex pathophysiology of acute mountain sickness (AMS) remains poorly understood and is likely to involve maladaptive responses of the respiratory, renal and cerebrovascular systems to hypoxia. Using stepwise linear regression, we tested the hypothesis that exacerbated respiratory alkalosis, as a result of a brisk ventilatory response, sluggish renal compensation in acute hypoxia and dysregulation of cerebral perfusion predict AMS severity. We assessed the Lake Louise score (LLS, an index of AMS severity), fluid balance, ventilation, venous pH, bicarbonate, sodium and creatinine concentrations, body weight, urinary pH and cerebral blood flow [internal carotid artery (ICA) and vertebral artery (VA) blood flow and diameter], in 27 healthy individuals (13 women) throughout 10 h exposures to normobaric normoxia (fraction of inspired O2 = 0.21) and normobaric hypoxia (fraction of inspired O2 = 0.117, simulated 5000 m) in a randomized, single-blinded manner. In comparison to normoxia, hypoxia increased the LLS, ventilation, venous and urinary pH, and blood flow and diameter in the ICA and VA, while venous concentrations of both bicarbonate and creatinine were decreased (P < 0.001 for all). There were significant correlations between AMS severity and the rates of change in blood pH, sodium concentration and VA diameter and more positive fluid balance (P < 0.05). Stepwise regression found increased blood pH [beta coefficient (β) = 0.589, P < 0.001] and VA diameter (β = 0.418, P = 0.008) to be significant predictors of AMS severity in our cohort [F(2, 20) = 16.1, R2 = 0.617, P < 0.001, n = 24], accounting for 62% of the variance in peak LLS. Using classic regression variable selection, our data implicate the degree of respiratory alkalosis and cerebrovascular dilatation in the early stages of AMS development.
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Affiliation(s)
- Holly Barclay
- Wellington Medical Technology Group, Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand.,Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Saptarshi Mukerji
- Emergency Department, Wellington Regional Hospital, Capital & Coast District Health Board, Wellington, New Zealand
| | - Bengt Kayser
- Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - Terrence O'Donnell
- Wellington Medical Technology Group, Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand.,Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Yu-Chieh Tzeng
- Wellington Medical Technology Group, Department of Surgery & Anaesthesia, University of Otago, Wellington, New Zealand.,Centre for Translational Physiology, University of Otago, Wellington, New Zealand
| | - Stephen Hill
- School of Psychology, Massey University, Palmerston North, New Zealand
| | - Katie Knapp
- School of Psychology, Massey University, Palmerston North, New Zealand
| | - Stephen Legg
- Centre for Ergonomics, Occupational Health and Safety, Massey University, Palmerston North, New Zealand
| | - Dan Frei
- Department of Anaesthesia and Pain Medicine, Wellington Regional Hospital, Capital & Coast District Health Board, Wellington, New Zealand
| | - Jui-Lin Fan
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
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16
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Steady-state cerebral blood flow regulation at altitude: interaction between oxygen and carbon dioxide. Eur J Appl Physiol 2019; 119:2529-2544. [DOI: 10.1007/s00421-019-04206-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 08/06/2019] [Indexed: 02/07/2023]
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17
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Howe CA, Ainslie PN, Tremblay JC, Carter HH, Patrician A, Stembridge M, Williams A, Drane AL, Delorme E, Rieger MG, Tymko MM, Gasho C, Santoro A, MacLeod DB, Hoiland RL. UBC-Nepal Expedition: Haemoconcentration underlies the reductions in cerebral blood flow observed during acclimatization to high altitude. Exp Physiol 2019; 104:1963-1972. [PMID: 31410899 DOI: 10.1113/ep087663] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 08/13/2019] [Indexed: 12/16/2022]
Abstract
NEW FINDINGS What is the central question of this study? The aim was to evaluate the degree to which increases in haematocrit alter cerebral blood flow and cerebral oxygen delivery during acclimatization to high altitude. What is the main finding and its importance? Through haemodilution, we determined that, after 1 week of acclimatization, the primary mechanism contributing to the cerebral blood flow response during acclimatization is an increase in haemoglobin and haematocrit. The remaining contribution to the cerebral blood flow response during acclimatization is likely to be attributable to ventilatory acclimatization. ABSTRACT At high altitude, an increase in haematocrit (Hct) is achieved through altitude-induced diuresis and erythropoiesis, both of which result in increased arterial oxygen content. Given the impact of alterations in Hct on oxygen content, haemoconcentration has been hypothesized to mediate, in part, the attenuation of the initial elevation in cerebral blood flow (CBF) at high altitude. To test this hypothesis, healthy men (n = 13) ascended to 5050 m over 9 days without the aid of prophylactic acclimatization medications. After 1 week of acclimatization at 5050 m, participants were haemodiluted by rapid saline infusion (2.10 ± 0.28 l) to return Hct towards pre-acclimatization values. Arterial blood gases, Hct, global CBF (duplex ultrasound) and haemodynamic variables were measured after initial arrival at 5050 m and after 1 week of acclimatization at high altitude, before and after the haemodilution protocol. After 1 week at 5050 m, the Hct increased from 42.5 ± 2.5 to 49.6 ± 2.5% (P < 0.001), and it was subsequently reduced to 45.6 ± 2.3% (P < 0.001) after haemodilution. Global CBF decreased from 844 ± 160 to 619 ± 136 ml min-1 (P = 0.033) after 1 week of acclimatization and increased to 714 ± 204 ml min -1 (P = 0.045) after haemodilution. Despite the significant changes in Hct, and thus oxygen content, cerebral oxygen delivery was unchanged at all time points. Furthermore, these observations occurred in the absence of any changes in mean arterial blood pressure, cardiac output, arterial blood pH or oxygen saturation pre- and posthaemodilution. These data highlight the influence of Hct in the regulation of CBF and are the first to demonstrate experimentally that haemoconcentration contributes to the reduction in CBF during acclimatization to altitude.
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Affiliation(s)
- Connor A Howe
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Joshua C Tremblay
- Cardiovascular Stress Response Laboratory, School of Kinesiology and Health Studies, Queen's University, Kingston, ON, Canada
| | - Howard H Carter
- Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - Alex Patrician
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Mike Stembridge
- Cardiff Centre for Exercise and Health, Cardiff Metropolitan University, Cardiff, UK
| | - Alex Williams
- International Collaboration on Repair Discoveries, University of British Columbia, Vancouver, BC, Canada
| | - Aimee L Drane
- Cardiff Centre for Exercise and Health, Cardiff Metropolitan University, Cardiff, UK
| | - Eric Delorme
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Mathew G Rieger
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Michael M Tymko
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
| | - Chris Gasho
- VA Loma Linda Healthcare System and Loma Linda University School of Medicine, Loma Linda, CA, USA
| | - Antoinette Santoro
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - David B MacLeod
- Department of Anesthesiology, Duke University Medical Center, Durham, NC, USA
| | - Ryan L Hoiland
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia - Okanagan Campus, Kelowna, BC, Canada
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18
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De Bels D, Pierrakos C, Bruneteau A, Reul F, Crevecoeur Q, Marrone N, Vissenaeken D, Borgers G, Balestra C, Honoré PM, Theunissen S. Variation of Cognitive Function During a Short Stay at Hypobaric Hypoxia Chamber (Altitude: 3842 M). Front Physiol 2019; 10:806. [PMID: 31316394 PMCID: PMC6611417 DOI: 10.3389/fphys.2019.00806] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
Objective To observe the effects of a fast-acute ascent to high altitude on brain cognitive function and transcranial doppler parameters in order to understand the physiological countermeasures of hypoxia. Methods 17 high-altitude-naïve male subjects (mean age was 26.3 ± 8.1 years) participated in the study. We measured Critical Flicker Fusion Frequency (CFFF), blood oxygen saturation, Psychology Experiment Building (PEBL) including three tests (Modified Math Processing Task, Perceptual Vigilance Task, and Time Estimation Task), as well as Cerebral Blood Flow index (CBFi), mean cerebral artery Systolic and diastolic velocities, Cerebral Pulsatility index (CPi), and heart Rate. All were measured at sea level, at least 1 h after arrival at the hypobaric hypoxia equivalent of 3842 m and 1 h after return to sea level. Results Under acute exposure to hypobaric hypoxic conditions, significant decrease in CFFF [42.1 ± 1 vs. 43.5 ± 1.7 Hz at sea level (asl), p < 0.01], CBFi (611 ± 51 vs. 665 ± 71 asl, p < 0.01) and blood oxygen saturation (83 ± 4% vs. 98 ± 1% asl, p < 0.001) as compared to pre-ascent values were observed. Physiological countermeasures to hypoxia could be involved as there was no significant change in neuropsychometric tests, Systolic and Diastolic velocities and CPi. A significant increase in Heart Rate (81 ± 15 bpm vs. 66 ± 15 bpm asl, p < 0.001) was observed. All parameters returned to their basal values 1 h after regaining sea level. Conclusion Hypoxia results in a decrease in CFFF, CBFi and oxygen saturation and in an increase in heart rate. As it decreased, Cerebral Blood Flow index does not seem to be the physiological measurement of choice to hypoxia explaining the maintenance of cognitive performance after acute exposure to hypobaric hypoxia and requires further investigation. Cerebral oxygen delivery and extraction could be one of the underlying mechanisms.
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Affiliation(s)
- D De Bels
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium.,Unit of Oxygen Study, Translational Research Laboratory, Université Libre de Bruxelles, Brussels, Belgium.,Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - C Pierrakos
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium.,Unit of Oxygen Study, Translational Research Laboratory, Université Libre de Bruxelles, Brussels, Belgium
| | - A Bruneteau
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - F Reul
- Faculty of Medicine, Université catholique de Louvain, Brussels, Belgium
| | - Q Crevecoeur
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - N Marrone
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - D Vissenaeken
- Hypobaric Chamber, Queen Astrid Military Hospital, Brussels, Belgium
| | - G Borgers
- Hypobaric Chamber, Queen Astrid Military Hospital, Brussels, Belgium
| | - C Balestra
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
| | - P M Honoré
- Department of Intensive Care Medicine, Brugmann University Hospital, Brussels, Belgium
| | - S Theunissen
- Laboratory of Integrative Physiology, Haute Ecole Bruxelles-Brabant, Brussels, Belgium
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19
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Xing CY, Serrador JM, Knox A, Ren LH, Zhao P, Wang H, Liu J. Cerebral Blood Flow, Oxygen Delivery, and Pulsatility Responses to Oxygen Inhalation at High Altitude: Highlanders vs. Lowlanders. Front Physiol 2019; 10:61. [PMID: 30792663 PMCID: PMC6375252 DOI: 10.3389/fphys.2019.00061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 01/18/2019] [Indexed: 01/24/2023] Open
Abstract
Objective: To determine whether the acute cerebral hemodynamic responses to oxygen inhalation are impacted by race or acclimation to high altitude. Methods: Three groups of young healthy males, who were Tibetans (highlanders, n = 15) with lifelong exposure to high altitude, and Han Chinese (lowlanders) with five-year (Han-5 yr, n = 15) and three-day (Han-3 d, n = 16) exposures, participated in the study at an altitude of 3658 m. Cerebral blood flow velocity (CBFV) was recorded for three minutes prior to and during pure oxygen inhalation (2 L/min), respectively, using a transcranial color-coded duplex (TCCD) sonography at the middle cerebral artery (MCA). The blood draw and simultaneous monitoring of blood pressure (BP), heart rate (HR), and finger arterial oxygen saturation (SaO2) were also performed. Results: Values are Mean ± SEM. The three groups had similar demographic characteristics and HR responses, with the group differences (P < 0.05) found in hemoglobin concentration (16.9 ± 0.9, 18.4 ± 1.3, and 15.5 ± 1.0 gm/dL), baseline BPs and HR as expected. Both the Tibetans and Han-5yr groups presented blunted BP responses to O2-inhalation when compared to the Han-3d group; more interestingly, the Tibetans showed significantly reduced responses compared with Han-5yr and Han-3d in CBFV, cerebral oxygen delivery (COD), and pulsatility index (PI) as assessed by Δ%CBFV/ΔSaO2 (-1.50 ± 0.25 vs. -2.24 ± 0.25 and -2.23 ± 0.27, P = 0.049 and 0.048), Δ%COD/ΔSaO2 (-0.52 ± 0.27 vs. -1.33 ± 0.26 and -1.38 ± 0.28, P = 0.044 and 0.031), and Δ%PI (7 ± 2 vs. 16 ± 3 and 16 ± 3 %, P = 0.036 and 0.023), respectively. Conclusion: These findings provide evidence on the Tibetans trait of a distinct cerebral hemodynamic regulatory pattern to keep more stable cerebral blood flow (CBF), oxygen delivery, and pulsatility in response to oxygen inhalation as compared with Han Chinese, which is likely due to a genetic adaptation to altitude.
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Affiliation(s)
- Chang-Yang Xing
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Jorge M Serrador
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Allan Knox
- Exercise Science Department, California Lutheran University, Thousand Oaks, CA, United States
| | - Li-Hua Ren
- General Hospital of Tibet Military Area Command, Lhasa, China
| | - Ping Zhao
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Hong Wang
- Department of Ultrasound Diagnostics, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
| | - Jie Liu
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.,Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, Newark, NJ, United States
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20
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Cramer NP, Korotcov A, Bosomtwi A, Xu X, Holman DR, Whiting K, Jones S, Hoy A, Dardzinski BJ, Galdzicki Z. Neuronal and vascular deficits following chronic adaptation to high altitude. Exp Neurol 2018; 311:293-304. [PMID: 30321497 DOI: 10.1016/j.expneurol.2018.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/20/2018] [Accepted: 10/10/2018] [Indexed: 02/03/2023]
Abstract
We sought to understand the mechanisms underlying cognitive deficits that are reported to affect non-native subjects following their prolonged stay and/or work at high altitude (HA). We found that mice exposed to a simulated environment of 5000 m exhibit deficits in hippocampal learning and memory accompanied by abnormalities in brain MR imaging. Exposure (1-8 months) to HA led to an increase in brain ventricular volume, a reduction in relative cerebral blood flow and changes in diffusion tensor imaging (DTI) derived parameters within the hippocampus and corpus callosum. Furthermore, neuropathological examination revealed significant expansion of the neurovascular network, microglia activation and demyelination within the corpus callosum. Electrophysiological recordings from the corpus callosum indicated that axonal excitabilities are increased while refractory periods are longer despite a lack of change in action potential conduction velocities of both myelinated and unmyelinated fibers. Next generation RNA-sequencing identified alterations in hippocampal and amygdala transcriptome signaling pathways linked to angiogenesis, neuroinflammation and myelination. Our findings reveal that exposure to hypobaric-hypoxia triggers maladaptive responses inducing cognitive deficits and suggest potential mechanisms underlying the adverse impacts of staying or traveling at high altitude.
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Affiliation(s)
- Nathan P Cramer
- Department of Anatomy, Physiology and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Alexandru Korotcov
- Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Department of Radiology and Radiological Sciences, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Asamoah Bosomtwi
- Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Department of Radiology and Radiological Sciences, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Xiufen Xu
- Department of Anatomy, Physiology and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Derek R Holman
- Department of Anatomy, Physiology and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Molecular & Cell Biology Graduate Program, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, MD, United States
| | - Kathleen Whiting
- Department of Anatomy, Physiology and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Neuroscience Graduate Program, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Scott Jones
- Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Department of Radiology and Radiological Sciences, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Andrew Hoy
- Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Department of Radiology and Radiological Sciences, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Bernard J Dardzinski
- Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Department of Radiology and Radiological Sciences, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Zygmunt Galdzicki
- Department of Anatomy, Physiology and Genetics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Center for Neuroscience and Regenerative Medicine, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States; Molecular & Cell Biology Graduate Program, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, MD, United States; Neuroscience Graduate Program, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
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21
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Ventilatory and cerebrovascular regulation and integration at high-altitude. Clin Auton Res 2018; 28:423-435. [PMID: 29574504 DOI: 10.1007/s10286-018-0522-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 03/09/2018] [Indexed: 01/17/2023]
Abstract
Ascent to high-altitude elicits compensatory physiological adaptations in order to improve oxygenation throughout the body. The brain is particularly vulnerable to the hypoxemia of terrestrial altitude exposure. Herein we review the ventilatory and cerebrovascular changes at altitude and how they are both implicated in the maintenance of oxygen delivery to the brain. Further, the interdependence of ventilation and cerebral blood flow at altitude is discussed. Following the acute hypoxic ventilatory response, acclimatization leads to progressive increases in ventilation, and a partial mitigation of hypoxemia. Simultaneously, cerebral blood flow increases during initial exposure to altitude when hypoxemia is the greatest. Following ventilatory acclimatization to altitude, and an increase in hemoglobin concentration-which both underscore improvements in arterial oxygen content over time at altitude-cerebral blood flow progressively decreases back to sea-level values. The complimentary nature of these responses (ventilatory, hematological and cerebral) lead to a tightly maintained cerebral oxygen delivery while at altitude. Despite this general maintenance of global cerebral oxygen delivery, the manner in which this occurs reflects integration of these physiological responses. Indeed, ventilation directly influences cerebral blood flow by determining the prevailing blood gas and acid/base stimuli at altitude, but cerebral blood flow may also influence ventilation by altering central chemoreceptor stimulation via central CO2 washout. The causes and consequences of the integration of ventilatory and cerebral blood flow regulation at high altitude are outlined.
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22
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Wang X, Wei W, Yuan F, Li S, Lin J, Zhang J. Regional cerebral blood flow in natives at high altitude: An arterial spin labeled MRI study. J Magn Reson Imaging 2018; 48:708-717. [PMID: 29493838 DOI: 10.1002/jmri.25996] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Accepted: 02/13/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND It is known that a neurologic sequence occurs at high altitudes (HA); hence, cerebral blood flow (CBF) might vary by altitude. PURPOSE To use arterial spin labeled (ASL) MRI to evaluate absolute CBF differences between subjects who live at HA and lowlands. STUDY TYPE Cohort prospective trial. POPULATION In all, 64 HA Tibetans, 19 lowland Tibetans, and 25 lowland Han subjects. FIELD STRENGTH/SEQUENCE CBF was measured with the pulsed ASL sequence at 3T. ASSESSMENT CBF was correlated with abode altitude in HA Tibetans; CBF differences among HA Tibetans, lowland Tibetans, and lowland Han subjects was assessed. STATISTICAL TESTS Pearson correlation assessed the correlation. Independent t-tests analyzed group differences. RESULTS In HA Tibetans, CBF decreased with altitude in the bilateral anterior and posterior cingulate gyri, fusiform gyrus, cerebellar tonsil and cortices, and thalamus as well as left middle and inferior temporal gyri and right insula (P < 0.05); HA Tibetans (vs. lowland Tibetans) had lower CBF in the left hemisphere (precuneus, anterior cingulate gyrus, fusiform gyrus, and lingual gyrus) and right hemisphere (superior parietal lobule, precuneus, posterior cingulate gyrus, and cerebellar tonsil), while they had higher CBF in the left inferior parietal lobule, lentiform nucleus, and inferior frontal gyrus (P < 0.05). The overlapping regions, in which CBF in HA Tibetans correlated with altitude and decreased (vs. lowland Tibetans), were selected for region of interest analysis, and the results showed lower CBF in HA Tibetans than lowland Han subjects (P < 0.05). DATA CONCLUSION HA adaptation in Tibetans is associated with a decrease of regional CBF. LEVEL OF EVIDENCE 2 Technical Efficacy: Stage 4 J. Magn. Reson. Imaging 2018.
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Affiliation(s)
- Xiaochuan Wang
- Department of Neurology, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Wenping Wei
- MRI Center, First Affiliated Hospital of Xiamen University, Xiamen, China
| | - Fengjuan Yuan
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
| | - Shanhua Li
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
| | - Jianzhong Lin
- Magnetic Resonance Center, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, Medical College of Xiamen University, Xiamen, China
- Institute for Brain Research and Rehabilitation, South China Normal University, Guangzhou, China
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23
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Cho SY, So WY, Roh HT. The Effects of Taekwondo Training on Peripheral Neuroplasticity-Related Growth Factors, Cerebral Blood Flow Velocity, and Cognitive Functions in Healthy Children: A Randomized Controlled Trial. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2017; 14:ijerph14050454. [PMID: 28441325 PMCID: PMC5451905 DOI: 10.3390/ijerph14050454] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/21/2017] [Accepted: 04/22/2017] [Indexed: 11/26/2022]
Abstract
Although regular Taekwondo (TKD) training has been reported to be effective for improving cognitive function in children, the mechanism underlying this improvement remains unclear. The purpose of the present study was to observe changes in neuroplasticity-related growth factors in the blood, assess cerebral blood flow velocity, and verify the resulting changes in children’s cognitive function after TKD training. Thirty healthy elementary school students were randomly assigned to control (n = 15) and TKD (n = 15) groups. The TKD training was conducted for 60 min at a rating of perceived exertion (RPE) of 11–15, 5 times per week, for 16 weeks. Brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and insulin-like growth factor-1 (IGF-1) levels were measured by blood sampling before and after the training, and the cerebral blood flow velocities (peak systolic [MCAs], end diastolic [MCAd], mean cerebral blood flow velocities [MCAm], and pulsatility index [PI]) of the middle cerebral artery (MCA) were measured using Doppler ultrasonography. For cognitive function assessment, Stroop Color and Word Tests (Word, Color, and Color-Word) were administered along with other measurements. The serum BDNF, VEGF, and IGF-1 levels and the Color-Word test scores among the sub-factors of the Stroop Color and Word Test scores were significantly higher in the TKD group after the intervention (p < 0.05). On the other hand, no statistically significant differences were found in any factors related to cerebral blood flow velocities, or in the Word test and Color test scores (p > 0.05). Thus, 16-week TKD training did not significantly affect cerebral blood flow velocities, but the training may have been effective in increasing children’s cognitive function by inducing an increase in the levels of neuroplasticity-related growth factors.
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Affiliation(s)
- Su-Youn Cho
- Department of Taekwondo, Youngsan University, Yangsan-si 50510, Korea.
| | - Wi-Young So
- Sports and Health Care Major, College of Humanities and Arts, Korea National University of Transportation, Chungju-si 27469, Korea.
| | - Hee-Tae Roh
- Department of Physical Education, College of Arts and Physical Education, Dong-A University, Busan 49315, Korea.
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24
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Liu W, Liu J, Lou X, Zheng D, Wu B, Wang DJJ, Ma L. A longitudinal study of cerebral blood flow under hypoxia at high altitude using 3D pseudo-continuous arterial spin labeling. Sci Rep 2017; 7:43246. [PMID: 28240265 PMCID: PMC5327438 DOI: 10.1038/srep43246] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 01/20/2017] [Indexed: 12/14/2022] Open
Abstract
Changes in cerebral blood flow (CBF) may occur with acute exposure to high altitude; however, the CBF of the brain parenchyma has not been studied to date. In this study, identical magnetic resonance scans using arterial spin labeling (ASL) were performed to study the haemodynamic changes at both sea level and high altitude. We found that with acute exposure to high altitude, the CBF in acute mountain sickness (AMS) subjects was higher (P < 0.05), while the CBF of non-AMS subjects was lower (P > 0.05) compared with those at sea level. Moreover, magnetic resonance angiography in both AMS and non-AMS subjects showed a significant increase in the cross-sectional areas of the internal carotid, basilar, and middle cerebral arteries on the first day at high altitude. These findings support that AMS may be related to increased CBF rather than vasodilation; these results contradict most previous studies that reported no relationship between CBF changes and the occurrence of AMS. This discrepancy may be attributed to the use of ASL for CBF measurement at both sea level and high altitude in this study, which has substantial advantages over transcranial Doppler for the assessment of CBF.
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Affiliation(s)
- Wenjia Liu
- Department of Radiology, Chinese PLA General Hospital, Beijing, China
| | - Jie Liu
- Department of Radiology, Tibet Military General Hospital, Lhasa, Tibet, China
| | - Xin Lou
- Department of Radiology, Chinese PLA General Hospital, Beijing, China.,Department of Neurology, University of California, Los Angeles, CA, USA
| | - Dandan Zheng
- GE Healthcare, MR Research China, Beijing, China
| | - Bing Wu
- GE Healthcare, MR Research China, Beijing, China
| | - Danny J J Wang
- Department of Neurology, University of California, Los Angeles, CA, USA
| | - Lin Ma
- Department of Radiology, Chinese PLA General Hospital, Beijing, China
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25
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Wei W, Wang X, Gong Q, Fan M, Zhang J. Cortical Thickness of Native Tibetans in the Qinghai-Tibetan Plateau. AJNR Am J Neuroradiol 2017; 38:553-560. [PMID: 28104637 DOI: 10.3174/ajnr.a5050] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 10/24/2016] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE High-altitude environmental factors and genetic variants together could have exerted their effects on the human brain. The present study was designed to investigate the cerebral morphology in high-altitude native Tibetans. MATERIALS AND METHODS T1-weighted brain images were obtained from 77 Tibetan adolescents on the Qinghai-Tibetan Plateau (altitude, 2300-5300 m) and 80 matched Han controls living at sea level. Cortical thickness, curvature, and sulcus were analyzed by using FreeSurfer. RESULTS Cortical thickness was significantly decreased in the left posterior cingulate cortex, lingual gyrus, superior parietal cortex, precuneus, and rostral middle frontal cortex and the right medial orbitofrontal cortex, lateral occipital cortex, precuneus, and paracentral lobule. Curvature was significantly decreased in the left superior parietal cortex and right superior marginal gyrus; the depth of the sulcus was significantly increased in the left inferior temporal gyrus and significantly decreased in the right superior marginal gyrus, superior temporal gyrus, and insular cortex. Moreover, cortical thickness was negatively correlated with altitude in the left superior and middle temporal gyri, rostral middle frontal cortex, insular cortex, posterior cingulate cortex, precuneus, lingual gyrus, and the right superior temporal gyrus. Curvature was positively correlated with altitude in the left rostral middle frontal cortex, insular cortex, and middle temporal gyrus. The depth of the sulcus was negatively correlated with altitude in the left lingual gyrus and right medial orbitofrontal cortex. CONCLUSIONS Differences in cortical morphometry in native Tibetans may reflect adaptations related to high altitude.
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Affiliation(s)
- W Wei
- From the MRI Center (W.W.), First Affiliated Hospital of Xiamen University, Xiamen, China.,Institute of Brain Disease and Cognition (W.W., J.Z.), Medical College of Xiamen University, Xiamen, China
| | - X Wang
- Department of Neurology (X.W.), Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Q Gong
- Huaxi Magnetic Resonance Research Center (Q.G.), West China Hospital, Sichuan University, Chengdu, China
| | - M Fan
- Department of Cognitive Sciences (M.F.), Institute of Basic Medical Sciences, Beijing, China
| | - J Zhang
- Institute of Brain Disease and Cognition (W.W., J.Z.), Medical College of Xiamen University, Xiamen, China
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26
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Characteristics of EEG activity during high altitude hypoxia and lowland reoxygenation. Brain Res 2016; 1648:243-249. [DOI: 10.1016/j.brainres.2016.07.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 06/12/2016] [Accepted: 07/12/2016] [Indexed: 11/20/2022]
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27
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Liu J, Liu Y, Ren LH, Li L, Wang Z, Liu SS, Li SZ, Cao TS. Effects of race and sex on cerebral hemodynamics, oxygen delivery and blood flow distribution in response to high altitude. Sci Rep 2016; 6:30500. [PMID: 27503416 PMCID: PMC4977556 DOI: 10.1038/srep30500] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 07/06/2016] [Indexed: 11/25/2022] Open
Abstract
To assess racial, sexual, and regional differences in cerebral hemodynamic response to high altitude (HA, 3658 m). We performed cross-sectional comparisons on total cerebral blood flow (TCBF = sum of bilateral internal carotid and vertebral arterial blood flows = QICA + QVA), total cerebrovascular resistance (TCVR), total cerebral oxygen delivery (TCOD) and QVA/TCBF (%), among six groups of young healthy subjects: Tibetans (2-year staying) and Han (Han Chinese) at sea level, Han (2-day, 1-year and 5-year) and Tibetans at HA. Bilateral ICA and VA diameters and flow velocities were derived from duplex ultrasonography; and simultaneous measurements of arterial pressure, oxygen saturation, and hemoglobin concentration were conducted. Neither acute (2-day) nor chronic (>1 year) responses showed sex differences in Han, except that women showed lower TCOD compared with men. Tibetans and Han exhibited different chronic responses (percentage alteration relative to the sea-level counterpart value) in TCBF (−17% vs. 0%), TCVR (22% vs. 12%), TCOD (0% vs. 10%) and QVA/TCBF (0% vs. 2.4%, absolute increase), with lower resting TCOD found in SL- and HA-Tibetans. Our findings indicate racial but not sex differences in cerebral hemodynamic adaptations to HA, with Tibetans (but not Han) demonstrating an altitude-related change of CBF distribution.
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Affiliation(s)
- Jie Liu
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yang Liu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Li-Hua Ren
- General Hospital of Tibet Military Area Command, Lhasa, Tibet Autonomous Region, China
| | - Li Li
- Department of Ultrasonic Medicine, Affiliated Hospital of Tibet University for Nationalities, Xianyang, Shaanxi, China
| | - Zhen Wang
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shan-Shan Liu
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Su-Zhi Li
- General Hospital of Tibet Military Area Command, Lhasa, Tibet Autonomous Region, China
| | - Tie-Sheng Cao
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
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28
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Bhattarai S, Elson W, Pradhan R, Pandey P. Cervical artery dissection at high altitude: an overview of two patients. J Travel Med 2016; 24:taw067. [PMID: 27799499 DOI: 10.1093/jtm/taw067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 09/01/2016] [Indexed: 11/14/2022]
Abstract
While altitude illness is common in the Himalayas, conditions unrelated to altitude illness also occur. High altitude cerebral oedema HACE is a global phenomenon of gradual onset affecting both cerebral hemispheres. We outline two cases of cervical artery dissection presenting with sudden onset of focal neurological symptoms at high altitude.
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