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Ma YY, Li X, Yu ZY, Luo T, Tan CR, Bai YD, Xu G, Sun BD, Bu XL, Liu YH, Jin WS, Gao YQ, Zhou XF, Liu J, Wang YJ. Oral antioxidant edaravone protects against cognitive deficits induced by chronic hypobaric hypoxia at high altitudes. Transl Psychiatry 2024; 14:415. [PMID: 39362869 PMCID: PMC11450176 DOI: 10.1038/s41398-024-03133-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Revised: 09/20/2024] [Accepted: 09/25/2024] [Indexed: 10/05/2024] Open
Abstract
Chronic hypobaric hypoxia at high altitudes can impair cognitive functions, especially causing deficits in learning and memory, which require therapeutic intervention. Here, we showed that mice subjected to hypobaric hypoxia (simulating an altitude of 5000 m) for one month experienced significant cognitive impairment, accompanied by increased biomarker levels of oxidative stress in the brain and blood. Oral administration of a novel formulation of edaravone, a free radical scavenger approved for the treatment of ischaemic stroke and amyotrophic lateral sclerosis, significantly alleviated oxidative stress and cognitive impairments caused by chronic hypobaric hypoxia. Furthermore, oral edaravone treatment also mitigated neuroinflammation and restored hippocampal neural stem cell exhaustion. Additionally, periostin (Postn) is vital in the cognitive deficits caused by chronic hypobaric hypoxia and may be a molecular target of edaravone. In conclusion, our results suggest that oxidative stress plays a crucial role in the cognitive deficits caused by chronic hypobaric hypoxia and that oral edaravone is a potential medicine for protecting against cognitive deficits caused by chronic hypobaric hypoxia in high-altitude areas.
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Affiliation(s)
- Yuan-Yuan Ma
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Xin Li
- Army 953 Hospital, Shigatse Branch of Xinqiao Hospital, Third Military Medical University, Shigatse, 857000, China
| | - Zhong-Yuan Yu
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Tong Luo
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
| | - Cheng-Rong Tan
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Yu-Di Bai
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Gang Xu
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, 400038, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, 400038, China
- Key Laboratory of High Altitude and Frigidzone Medical Support, PLA, Chongqing, 400038, China
| | - Bin-Da Sun
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, 400038, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, 400038, China
- Key Laboratory of High Altitude and Frigidzone Medical Support, PLA, Chongqing, 400038, China
| | - Xian-Le Bu
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Yu-Hui Liu
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Wang-Sheng Jin
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China
| | - Yu-Qi Gao
- Institute of Medicine and Equipment for High Altitude Region, College of High Altitude Military Medicine, Third Military Medical University, Chongqing, 400038, China
- Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Chongqing, 400038, China
- Key Laboratory of High Altitude and Frigidzone Medical Support, PLA, Chongqing, 400038, China
| | - Xin-Fu Zhou
- Suzhou Auzone Biotech, Suzhou, 215123, China
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Juan Liu
- Department of Special Medicine, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
- Center for Hyperbaric Oxygen Medicine, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
| | - Yan-Jiang Wang
- Department of Neurology and Centre for Clinical Neuroscience, Daping Hospital, Third Military Medical University, Chongqing, 400042, China.
- Chongqing Key Laboratory of Ageing and Brain Diseases, Chongqing, 400042, China.
- State Key Laboratory of Trauma and Chemical Poisoning, Chongqing, 400042, China.
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Tao G, Ma H, Su Y. Effects of long-term exposure to high-altitude on episodic memory: The moderating role of daytime dysfunction. Physiol Behav 2024; 287:114700. [PMID: 39332594 DOI: 10.1016/j.physbeh.2024.114700] [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: 07/20/2024] [Revised: 09/14/2024] [Accepted: 09/20/2024] [Indexed: 09/29/2024]
Abstract
Chronic exposure to high-altitude hypoxic environments may influence short-term memory and working memory. However, its impact on long-term memory, specifically episodic memory, remains understudied. In this study, we systematically investigated the effects of long-term exposure to high altitude (3650 m) on episodic memory, including item memory and source memory. Moreover, we examined the moderating role of daytime dysfunction on the relationship between altitude and episodic memory. In total, 97 participants were enrolled in the study: 49 were from the high-altitude (HA) group, comprising those born and raised in low altitude (LA) areas (< 500 m) and had migrated to HA for 2∼3 years after turning 18; and 48 were from the LA group, who had never lived at high altitudes. Episodic memory was evaluated using a what-when-where task, whereas daytime dysfunction was measured by the Pittsburgh Sleep Quality Index. For item memory, hit rate and correct rejection rate were significantly lower in the HA group relative to the LA group. For source binding memory, the performance in what-where binding and what-when-where binding were decreased in the HA group, but the what-when binding did not differ between the two groups. Furthermore, the effects of altitude on hit rate, what-where binding, and what-when-where binding were significantly pronounced in individuals with higher levels of daytime dysfunction. These findings suggest that long-term exposure to high-altitude hypoxic environments influences episodic memory performance, including item recognition and source-binding memory. Specifically, spatial source memory is affected by high-altitude exposure, whereas temporal source memory remains unaffected. Moreover, these results highlight the importance of considering sleep quality, especially good daytime function, in maintaining optimal episodic memory function following chronic exposure to high altitudes.
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Affiliation(s)
- Getong Tao
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China.
| | - Yanjie Su
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
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3
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Hatch K, Lischka F, Wang M, Xu X, Stimpson CD, Barvir T, Cramer NP, Perl DP, Yu G, Browne CA, Dickstein DL, Galdzicki Z. The role of microglia in neuronal and cognitive function during high altitude acclimatization. Sci Rep 2024; 14:18981. [PMID: 39152179 PMCID: PMC11329659 DOI: 10.1038/s41598-024-69694-9] [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: 03/15/2024] [Accepted: 08/07/2024] [Indexed: 08/19/2024] Open
Abstract
Due to their interactions with the neurovasculature, microglia are implicated in maladaptive responses to hypobaric hypoxia at high altitude (HA). To explore these interactions at HA, pharmacological depletion of microglia with the colony-stimulating factor-1 receptor inhibitor, PLX5622, was employed in male C57BL/6J mice maintained at HA or sea level (SL) for 3-weeks, followed by assessment of ex-vivo hippocampal long-term potentiation (LTP), fear memory recall and microglial dynamics/physiology. Our findings revealed that microglia depletion decreased LTP and reduced glucose levels by 25% at SL but did not affect fear memory recall. At HA, the absence of microglia did not significantly alter HA associated deficits in fear memory or HA mediated decreases in peripheral glucose levels. In regard to microglial dynamics in the cortex, HA enhanced microglial surveillance activity, ablation of microglia resulted in increased chemotactic responses and decreased microglia tip proliferation during ball formation. In contrast, vessel ablation increased cortical microglia tip path tortuosity. In the hippocampus, changes in microglial dynamics were only observed in response to vessel ablation following HA. As the hippocampus is critical for learning and memory, poor hippocampal microglial context-dependent adaptation may be responsible for some of the enduring neurological deficits associated with HA.
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Affiliation(s)
- Kathleen Hatch
- Neuroscience Graduate Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Fritz Lischka
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Mengfan Wang
- Department of Electrical and Computer Engineering, Virginia Tech, Arlington, VA, USA
| | - Xiufen Xu
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Cheryl D Stimpson
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Tara Barvir
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Nathan P Cramer
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD, 21201, USA
| | - Daniel P Perl
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Guoqiang Yu
- Department of Electrical and Computer Engineering, Virginia Tech, Arlington, VA, USA
| | - Caroline A Browne
- Neuroscience Graduate Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Pharmacology and Molecular Therapeutics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Dara L Dickstein
- Neuroscience Graduate Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- The Henry M. Jackson Foundation for the Advancement of Military Medicine Inc. (HJF), 6720A Rockledge Drive, Bethesda, MD, 20817, USA
- Department of Pathology, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Zygmunt Galdzicki
- Neuroscience Graduate Program, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
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Gao J, Guo Z, Zhao M, Cheng X, Jiang X, Liu Y, Zhang W, Yue X, Fei X, Jiang Y, Chen L, Zhang S, Zhao T, Zhu L. Lipidomics and mass spectrometry imaging unveil alterations in mice hippocampus lipid composition exposed to hypoxia. J Lipid Res 2024; 65:100575. [PMID: 38866327 PMCID: PMC11333011 DOI: 10.1016/j.jlr.2024.100575] [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: 03/21/2024] [Revised: 06/03/2024] [Accepted: 06/05/2024] [Indexed: 06/14/2024] Open
Abstract
Lipids are components of cytomembranes that are involved in various biochemical processes. High-altitude hypoxic environments not only affect the body's energy metabolism, but these environments can also cause abnormal lipid metabolism involved in the hypoxia-induced cognitive impairment. Thus, comprehensive lipidomic profiling of the brain tissue is an essential step toward understanding the mechanism of cognitive impairment induced by hypoxic exposure. In the present study, mice showed reduced new-object recognition and spatial memory when exposed to hypobaric hypoxia for 1 day. Histomorphological staining revealed significant morphological and structural damage to the hippocampal tissue, along with prolonged exposure to hypobaric hypoxia. Dynamic lipidomics of the mouse hippocampus showed a significant shift in both the type and distribution of phospholipids, as verified by spatial lipid mapping. Collectively, a diverse and dynamic lipid composition in mice hippocampus was uncovered, which deepens our understanding of biochemical changes during sustained hypoxic exposure and could provide new insights into the cognitive decline induced by high-altitude hypoxia exposure.
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Affiliation(s)
- Jiayue Gao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Zhiying Guo
- Hepato-pancreato-biliary Center, Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Ming Zhao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xiang Cheng
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xiufang Jiang
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yikun Liu
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Wenpeng Zhang
- State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, China
| | - Xiangpei Yue
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xuechao Fei
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Yaqun Jiang
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Lu Chen
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Shaojie Zhang
- Department of Gastroenterology, The Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Tong Zhao
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Lingling Zhu
- Department of Brain Plasticity, Beijing Institute of Basic Medical Sciences, Beijing, China; Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China.
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5
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Guo F, Wang C, Tao G, Ma H, Zhang J, Wang Y. A longitudinal study on the impact of high-altitude hypoxia on perceptual processes. Psychophysiology 2024; 61:e14548. [PMID: 38385977 DOI: 10.1111/psyp.14548] [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: 05/22/2023] [Revised: 02/05/2024] [Accepted: 02/07/2024] [Indexed: 02/23/2024]
Abstract
This study aimed to explore the neural mechanisms underlying high-altitude (HA) adaptation and deadaptation in perceptual processes in lowlanders. Eighteen healthy lowlanders were administered a facial S1-S2 matching task that included incomplete face (S1) and complete face (S2) photographs combined with ERP technology. Participants were tested at four time points: shortly before they departed the HA (Test 1), twenty-five days after entering the HA (Test 2), and one week (Test 3) and one month (Test 4) after returning to the lowlands. Compared with those at sea level (SL), shorter reaction times (RTs), shorter latencies of P1 and N170, and larger amplitudes of complete face N170 were found in HAs. After returning to SL, compared with that of HA, the amplitude of the incomplete face P1 was smaller after one week, and the complete face was smaller after one month. The right hemisphere N170 amplitude was greater after entering HA and one week after returning to SL than at baseline, but it returned to baseline after one month. Taken together, the current findings suggest that HA adaptation increases visual cortex excitation to accelerate perceptual processing. More mental resources are recruited during the configural encoding stage of complete faces after HA exposure. The perceptual processes affected by HA exposure are reversible after returning to SL, but the low-level processing stage differs between incomplete and complete faces due to neural compensation mechanisms. The configural encoding stage in the right hemisphere is affected by HA exposure and requires more than one week but less than one month to recover to baseline.
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Affiliation(s)
- Fumei Guo
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Changming Wang
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, National Center for Neurological Disorders, Beijing, China
| | - Getong Tao
- CAS Key Laboratory of Mental Health, Institute of Psychology, Beijing, China
- Department of Psychology, 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
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
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6
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Su R, Jia S, Zhang N, Wang Y, Li H, Zhang D, Ma H, Su Y. The effects of long-term high-altitude exposure on cognition: A meta-analysis. Neurosci Biobehav Rev 2024; 161:105682. [PMID: 38642865 DOI: 10.1016/j.neubiorev.2024.105682] [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: 03/24/2024] [Revised: 04/14/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024]
Abstract
Long-term high altitudes (HA) exposure's impact on cognition has yielded inconsistent findings in previous research. To address this, we conducted a meta-analysis of 49 studies (6191 individuals) to comprehensively evaluate this effect. Moderating factors such as cognitive task type, altitude (1500-2500 m, 2500-4000 m, and above 4000 m), residential type (chronic and lifelong), adaptation level and demographic factors were analyzed. Cognitive tasks were classified into eight categories: perceptual processes, psychomotor function, long-term memory, working memory, inhibitory control, problem-solving, language, and others. Results revealed a moderate negative effect of HA on cognitive performance (g = -.40, SE =.18, 95% CI = -.76 to -.05). Psychomotor function and long-term memory notably experience the most pronounced decline, while working memory and language skills show moderate decreases due to HA exposure. However, perceptual processes, inhibitory control, and problem-solving abilities remain unaffected. Moreover, residing at altitudes above 4000 m and being a HA immigrant are associated with significant cognitive impairment. In summary, our findings indicate a selective adaptation of cognitive performance to HA conditions.
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Affiliation(s)
- Rui Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China; Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Shurong Jia
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Niannian Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yiyi Wang
- Department of Psychology, University of Chicago, Chicago, IL 60637, United States
| | - Hao Li
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Delong Zhang
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China; School of Psychology, Center for Studies of Psychological Application, and Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou, China
| | - Hailin Ma
- Key Laboratory of High Altitudes Brain Science and Environmental Acclimation, Tibet University, Lhasa 85000, China
| | - Yanjie Su
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100871, China.
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7
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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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8
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Fan H, Meng Y, Zhu L, Fan M, Wang D, Zhao Y. A review of methods for assessment of cognitive function in high-altitude hypoxic environments. Brain Behav 2024; 14:e3418. [PMID: 38409925 PMCID: PMC10897364 DOI: 10.1002/brb3.3418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/03/2024] [Accepted: 01/13/2024] [Indexed: 02/28/2024] Open
Abstract
Hypoxic environments like those present at high altitudes may negatively affect brain function. Varying levels of hypoxia, whether acute or chronic, are previously shown to impair cognitive function in humans. Assessment and prevention of such cognitive impairment require detection of cognitive changes and impairment using specific cognitive function assessment tools. This paper summarizes the findings of previous research, outlines the methods for cognitive function assessment used at a high altitude, elaborates the need to develop standardized and systematic cognitive function assessment tools for high-altitude hypoxia environments.
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Affiliation(s)
- Haojie Fan
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Ying Meng
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Lingling Zhu
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
| | - Ming Fan
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
- School of Information Sciences & EngineeringLanzhou UniversityLanzhouChina
| | - Du‐Ming Wang
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
| | - Yong‐Qi Zhao
- Department of PsychologyZhejiang Sci‐Tech UniversityHangzhouChina
- Department of Cognitive and StressBeijing Institute of Basic Medical SciencesBeijingChina
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9
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Damgaard V, Mariegaard J, Lindhardsen JM, Ehrenreich H, Miskowiak KW. Neuroprotective Effects of Moderate Hypoxia: A Systematic Review. Brain Sci 2023; 13:1648. [PMID: 38137096 PMCID: PMC10741927 DOI: 10.3390/brainsci13121648] [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: 10/31/2023] [Revised: 11/22/2023] [Accepted: 11/23/2023] [Indexed: 12/24/2023] Open
Abstract
Emerging evidence highlights moderate hypoxia as a candidate treatment for brain disorders. This systematic review examines findings and the methodological quality of studies investigating hypoxia (10-16% O2) for ≥14 days in humans, as well as the neurobiological mechanisms triggered by hypoxia in animals, and suggests optimal treatment protocols to guide future studies. We followed the preferred reporting items for systematic reviews and meta-analysis (PRISMA) 2020. Searches were performed on PubMed/MEDLINE, PsycInfo, EMBASE, and the Cochrane Library, in May-September 2023. Two authors independently reviewed the human studies with the following tools: (1) revised Cochrane collaboration's risk of bias for randomized trials 2.0; (2) the risk of bias in nonrandomized studies of interventions. We identified 58 eligible studies (k = 8 human studies with N = 274 individuals; k = 48 animal studies) reporting the effects of hypoxia on cognition, motor function, neuroimaging, neuronal/synaptic morphology, inflammation, oxidative stress, erythropoietin, neurotrophins, and Alzheimer's disease markers. A total of 75% of human studies indicated cognitive and/or neurological benefits, although all studies were evaluated ashigh risk of bias due to a lack of randomization and assessor blinding. Low-dose intermittent or continuous hypoxia repeated for 30-240 min sessions, preferably in combination with motor-cognitive training, produced beneficial effects, and high-dose hypoxia with longer (≥6 h) durations and chronic exposure produced more adverse effects. Larger and methodologically stronger translational studies are warranted.
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Affiliation(s)
- Viktoria Damgaard
- Neurocognition and Emotion in Affective Disorders (NEAD) Centre, Copenhagen Affective Disorder Research Centre, Psychiatric Centre Copenhagen, Frederiksberg Hospital, Hovedvejen 17, DK-2000 Frederiksberg, Denmark; (V.D.); (J.M.)
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen, Denmark
| | - Johanna Mariegaard
- Neurocognition and Emotion in Affective Disorders (NEAD) Centre, Copenhagen Affective Disorder Research Centre, Psychiatric Centre Copenhagen, Frederiksberg Hospital, Hovedvejen 17, DK-2000 Frederiksberg, Denmark; (V.D.); (J.M.)
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen, Denmark
| | - Julie Marie Lindhardsen
- Neurocognition and Emotion in Affective Disorders (NEAD) Centre, Copenhagen Affective Disorder Research Centre, Psychiatric Centre Copenhagen, Frederiksberg Hospital, Hovedvejen 17, DK-2000 Frederiksberg, Denmark; (V.D.); (J.M.)
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen, Denmark
| | - Hannelore Ehrenreich
- University of Göttingen, 37075 Göttingen, Germany;
- Clinical Neuroscience, Max Planck Institute for Multidisciplinary Sciences, City Campus, 37075 Göttingen, Germany
| | - Kamilla Woznica Miskowiak
- Neurocognition and Emotion in Affective Disorders (NEAD) Centre, Copenhagen Affective Disorder Research Centre, Psychiatric Centre Copenhagen, Frederiksberg Hospital, Hovedvejen 17, DK-2000 Frederiksberg, Denmark; (V.D.); (J.M.)
- Department of Psychology, University of Copenhagen, Øster Farimagsgade 2A, DK-1353 Copenhagen, Denmark
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Temme LA, Wittels HL, Wishon MJ, St. Onge P, McDonald SM, Hecocks D, Wittels SH. Continuous Physiological Monitoring of the Combined Exposure to Hypoxia and High Cognitive Load in Military Personnel. BIOLOGY 2023; 12:1398. [PMID: 37997997 PMCID: PMC10669144 DOI: 10.3390/biology12111398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/25/2023]
Abstract
Military aviators endure high cognitive loads and hypoxic environments during flight operations, impacting the autonomic nervous system (ANS). The synergistic effects of these exposures on the ANS, however, are less clear. This study investigated the simultaneous effects of mild hypoxia and high cognitive load on the ANS in military personnel. This study employed a two-factor experimental design. Twenty-four healthy participants aged between 19 and 45 years were exposed to mild hypoxia (14.0% O2), normoxia (21.0% O2), and hyperoxia (33.0% O2). During each epoch (n = 5), participants continuously performed one 15 min and one 10 min series of simulated, in-flight tasks separated by 1 min of rest. Exposure sequences (hypoxia-normoxia and normoxia-hyperoxia) were separated by a 60 min break. Heart rate (HR), heart rate variability (HRV), and O2 saturation (SpO2) were continuously measured via an armband monitor (Warfighter MonitorTM, Tiger Tech Solutions, Inc., Miami, FL, USA). Paired and independent t-tests were used to evaluate differences in HR, HRV, and SpO2 within and between exposure sequences. Survival analyses were performed to assess the timing and magnitude of the ANS responses. Sympathetic nervous system (SNS) activity during hypoxia was highest in epoch 1 (HR: +6.9 bpm, p = 0.002; rMSSD: -9.7 ms, p = 0.003; SDNN: -11.3 ms, p = 0.003; SpO2: -8.4%, p < 0.0000) and appeared to slightly decline with non-significant increases in HRV. During normoxia, SNS activity was heightened, albeit non-significantly, in epoch 1, with higher HR (68.5 bpm vs. 73.0 bpm, p = 0.06), lower HRV (rMSSD: 45.1 ms vs. 38.7 ms, p = 0.09 and SDNN: 52.5 ms vs. 45.1 ms, p = 0.08), and lower SpO2 (-0.7% p = 0.05). In epochs 2-4, HR, HRV, and SpO2 trended towards baseline values. Significant between-group differences in HR, HRV, and O2 saturation were observed. Hypoxia elicited significantly greater HRs (+5.0, p = 0.03), lower rMSSD (-7.1, p = 0.03), lower SDNN (-8.2, p = 0.03), and lower SpO2 (-1.4%, p = 0.002) compared to normoxia. Hyperoxia appeared to augment the parasympathetic reactivation reflected by significantly lower HR, in addition to higher HRV and O2 relative to normoxia. Hypoxia induced a greater ANS response in military personnel during the simultaneous exposure to high cognitive load. The significant and differential ANS responses to varying O2 levels and high cognitive load observed highlight the importance of continuously monitoring multiple physiological parameters during flight operations.
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Affiliation(s)
- Leonard A. Temme
- Army Aeromedical Research Laboratory, Fort Novosel, AL 36362, USA; (L.A.T.); (P.S.O.)
| | | | - Michael J. Wishon
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
| | - Paul St. Onge
- Army Aeromedical Research Laboratory, Fort Novosel, AL 36362, USA; (L.A.T.); (P.S.O.)
| | - Samantha M. McDonald
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
- School of Kinesiology and Recreation, Illinois State University, Normal, IL 61761, USA
| | - Dustin Hecocks
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
| | - S. Howard Wittels
- Tiger Tech Solutions, Inc., Miami, FL 33140, USA (M.J.W.); (D.H.); (S.H.W.)
- Department of Anesthesiology, Mount Sinai Medical Center, Miami, FL 33140, USA
- Department of Anesthesiology, Wertheim School of Medicine, Florida International University, Miami, FL 33199, USA
- Miami Beach Anesthesiology Associates, Miami, FL 33140, USA
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11
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Cao Y, Cao S, Ge RL, Bao H, Mou Y, Ji W. Brain-aging related protein expression and imaging characteristics of mice exposed to chronic hypoxia at high altitude. Front Aging Neurosci 2023; 15:1268230. [PMID: 37849650 PMCID: PMC10577427 DOI: 10.3389/fnagi.2023.1268230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/18/2023] [Indexed: 10/19/2023] Open
Abstract
Objective To determine changes in protein expression related to brain aging and imaging features in mice after chronic hypoxia exposure at high altitude. Method A total of 24 healthy 4-week-old mice were randomly divided into high altitude hypoxia (HH) and plain control (PC) groups (n = 8 per group). HH mice were transported from Xi'an (450 m above sea level) to Maduo (4,300 m above sea level) while PC mice were raised in Xi'an. After 6 months, 7.0T magnetic resonance imaging (MRI) was performed. All mice completed T2-weighted imaging (T2WI), diffusion tensor imaging (DTI), resting-state functional MRI (rs-fMRI), arterial spin labeling (ASL), and magnetic resonance angiography (MRA) examinations. Next, brain slices were prepared and Nissl staining was used to observe morphological changes in neurons. Ultrastructural changes in neurons were observed by transmission electron microscopy. Expression changes of Caspase-3, klotho, P16, P21, and P53 at the gene and protein levels were detected by real-time PCR (RT-PCR) and Western blot. Results The number of neuronal Nissl bodies in the hippocampus and frontal cortex was significantly decreased in the HH group compared to the PC group. Some hippocampal and frontal cortical neurons were apoptotic, the nuclei were wrinkled, chromatin was aggregated, and most mitochondria were mildly swollen (crista lysis, fracture). Compared with the PC group, the HH group showed elevated expression of caspase-3 mRNA, P16 mRNA, P21 mRNA, and P53 mRNA in the hippocampus and frontal cortex. Expression of Klotho mRNA in the frontal cortex was also significantly decreased. Western blot results showed that caspase-3 protein expression in the hippocampus and frontal cortex of the HH group was increased compared with the PC group. Moreover, there was decreased Klotho protein expression and significantly increased P-P53 protein expression. Compared with the PC group, expression of P16 protein in the frontal cortex of the HH group was increased and the gray matter (GM) volume in the left visceral area, left caudate nucleus, and left piriform cortex was decreased. Furthermore, the amplitude of low frequency fluctuation was decreased in the left posterior nongranular insular lobe, right small cell reticular nucleus, left flocculus, left accessory flocculus, and left primary auditory area, but increased in the GM layer of the left superior colliculus. Regional homogeneity was decreased in the left and right olfactory regions, but increased in the left bed nucleus. After exposure to high altitude, functional connectivity (FC) between the bilateral caudate nucleus and thalamus, corpus callosum, cingulate gyrus, anterior limbic cortex, globus pallidus, and hippocampus was weakened. FC between the right caudate nucleus and hypothalamus and entorhinal cortex was also weakened. The fractional anisotropy value of the left hippocampus was decreased in the HH group. Compared with the PC group, the HH group showed significantly increased inner diameters of the bilateral common carotid artery and left internal carotid artery. The cerebral blood flow values of the bilateral cortex and bilateral hippocampus in the HH group did not change significantly. Conclusion Taken together, our findings show that chronic hypoxia exposure at high altitude may promote neuronal apoptosis and abnormal expression of related proteins, changing the structure and function of brain. These changes may contribute to brain aging.
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Affiliation(s)
- Yaxin Cao
- Tangdu Hospital of Air Force Military Medical University, Xi’an, China
| | - Shundao Cao
- Department of Neurology, Xi’an No. 1 Hospital, Xi’an, China
| | - Ri-Li Ge
- Research Center for High Altitude Medicine, Qinghai University, Xining, China
| | - Haihua Bao
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Yalin Mou
- Department of Medical Imaging Center, Qinghai University Affiliated Hospital, Xining, China
| | - Weizhong Ji
- Qinghai Provincial People’s Hospital, Xining, China
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12
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Reiser AE, Furian M, Lichtblau M, Buergin A, Schneider SR, Appenzeller P, Mayer L, Muralt L, Mademilov M, Abdyraeva A, Aidaralieva S, Muratbekova A, Akylbekov A, Sheraliev U, Shabykeeva S, Sooronbaev TM, Ulrich S, Bloch KE. Effect of acetazolamide on visuomotor performance at high altitude in healthy people 40 years of age or older-RCT. PLoS One 2023; 18:e0280585. [PMID: 36662903 PMCID: PMC9858039 DOI: 10.1371/journal.pone.0280585] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Accepted: 01/04/2023] [Indexed: 01/22/2023] Open
Abstract
OBJECTIVE Altitude travel is increasingly popular also for middle-aged and older tourists and professionals. Due to the sensitivity of the central nervous system to hypoxia, altitude exposure may impair visuomotor performance although this has not been extensively studied. Therefore, we investigated whether a sojourn at moderately high altitude is associated with visuomotor performance impairments in healthy adults, 40y of age or older, and whether this adverse altitude-effect can be prevented by acetazolamide, a drug used to prevent acute mountain sickness. METHODS In this randomized placebo-controlled parallel-design trial, 59 healthy lowlanders, aged 40-75y, were assigned to acetazolamide (375 mg/day, n = 34) or placebo (n = 25), administered one day before ascent and while staying at high altitude (3100m). Visuomotor performance was assessed at 760m and 3100m after arrival and in the next morning (post-sleep) by a computer-assisted test (Motor-Task-Manager). It quantified deviation of a participant-controlled cursor affected by rotation during target tracking. Primary outcome was the directional error during post-sleep recall of adaptation to rotation estimated by multilevel linear regression modeling. Additionally, adaptation, immediate recall, and correct test execution were evaluated. RESULTS Compared to 760m, assessments at 3100m with placebo revealed a mean (95%CI) increase in directional error during adaptation and immediate recall by 1.9° (0.2 to 3.5, p = 0.024) and 1.1° (0.4 to 1.8, p = 0.002), respectively. Post-sleep recall remained unchanged (p = NS), however post-sleep correct test execution was 14% less likely (9 to 19, p<0.001). Acetazolamide improved directional error during post-sleep recall by 5.6° (2.6 to 8.6, p<0.001) and post-sleep probability of correct test execution by 36% (30 to 42, p<0.001) compared to placebo. CONCLUSION In healthy individuals, 40y of age or older, altitude exposure impaired adaptation to and immediate recall and correct execution of a visuomotor task. Preventive acetazolamide treatment improved visuomotor performance after one night at altitude and increased the probability of correct test execution compared to placebo. CLINICALTRIALS.GOV IDENTIFIER ClinicalTrials.gov NCT03536520.
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Affiliation(s)
- Aurelia E. Reiser
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Michael Furian
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Mona Lichtblau
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Aline Buergin
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Simon R. Schneider
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Paula Appenzeller
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Laura Mayer
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Lara Muralt
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Maamed Mademilov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ainura Abdyraeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Shoira Aidaralieva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Aibermet Muratbekova
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Azamat Akylbekov
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Ulan Sheraliev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Saltanat Shabykeeva
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Talant M. Sooronbaev
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
- Department of Respiratory Medicine, National Center of Cardiology and Internal Medicine, Bishkek, Kyrgyz Republic
| | - Silvia Ulrich
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
| | - Konrad E. Bloch
- Department of Respiratory Medicine, University Hospital Zurich, Zurich, Switzerland
- Swiss-Kyrgyz High Altitude Medicine and Research Initiative, Zurich, Switzerland/ Bishkek, Kyrgyz Republic
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Cognition and Neuropsychological Changes at Altitude-A Systematic Review of Literature. Brain Sci 2022; 12:brainsci12121736. [PMID: 36552195 PMCID: PMC9775937 DOI: 10.3390/brainsci12121736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/05/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
High-altitude (HA) exposure affects cognitive functions, but studies have found inconsistent results. The aim of this systematic review was to evaluate the effects of HA exposure on cognitive functions in healthy subjects. A structural overview of the applied neuropsychological tests was provided with a classification of superordinate cognitive domains. A literature search was performed using PubMed up to October 2021 according to PRISMA guidelines. Eligibility criteria included a healthy human cohort exposed to altitude in the field (at minimum 2440 m [8000 ft]) or in a hypoxic environment in a laboratory, and an assessment of cognitive domains. The literature search identified 52 studies (29 of these were field studies; altitude range: 2440 m-8848 m [8000-29,029 ft]). Researchers applied 112 different neuropsychological tests. Attentional capacity, concentration, and executive functions were the most frequently studied. In the laboratory, the ratio of altitude-induced impairments (64.7%) was twice as high compared to results showing no change or improved results (35.3%), but altitudes studied were similar in the chamber compared to field studies. In the field, the opposite results were found (66.4 % no change or improvements, 33.6% impairments). Since better acclimatization can be assumed in the field studies, the findings support the hypothesis that sufficient acclimatization has beneficial effects on cognitive functions at HA. However, it also becomes apparent that research in this area would benefit most if a consensus could be reached on a standardized framework of freely available neurocognitive tests.
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Kiselev AR, Arablinsky NA, Mironov SA, Umetov MA, Berns SA, Yavelov IS, Drapkina OM. Physiological and pathophysiological aspects of short-term middle-altitude adaptation in humans. КАРДИОВАСКУЛЯРНАЯ ТЕРАПИЯ И ПРОФИЛАКТИКА 2022. [DOI: 10.15829/1728-8800-2022-3306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The review presents up-to-date information on the physiological and pathophysiological aspects of short-term middle-altitude adaptation in healthy individuals and patients with various chronic diseases. Unlike acute mountain sickness, which develops going to ≥3000, the physiological aspects of human adaptation to 2000-2500 m remain insufficiently studied. However, these altitudes are the most visited among tourist groups and individually.
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Affiliation(s)
- A. R. Kiselev
- National Medical Research Center for Therapy and Preventive Medicine
| | - N. A. Arablinsky
- National Medical Research Center for Therapy and Preventive Medicine
| | - S. A. Mironov
- National Medical Research Center for Therapy and Preventive Medicine
| | - M. A. Umetov
- Kh. M. BerbekovKabardino-Balkarian State University
| | - S. A. Berns
- National Medical Research Center for Therapy and Preventive Medicine
| | - I. S. Yavelov
- National Medical Research Center for Therapy and Preventive Medicine
| | - O. M. Drapkina
- National Medical Research Center for Therapy and Preventive Medicine
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15
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Kiselev AR, Arablinsky NA, Mironov SA, Umetov MA, Berns SA, Yavelov IS, Drapkina OM. Physiological and pathophysiological aspects of short-term middle-altitude adaptation in humans. КАРДИОВАСКУЛЯРНАЯ ТЕРАПИЯ И ПРОФИЛАКТИКА 2022. [DOI: 10.15829/1728-8800-20223306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
The review presents up-to-date information on the physiological and pathophysiological aspects of short-term middle-altitude adaptation in healthy individuals and patients with various chronic diseases. Unlike acute mountain sickness, which develops going to ≥3000, the physiological aspects of human adaptation to 2000-2500 m remain insufficiently studied. However, these altitudes are the most visited among tourist groups and individually.
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Affiliation(s)
- A. R. Kiselev
- National Medical Research Center for Therapy and Preventive Medicine
| | - N. A. Arablinsky
- National Medical Research Center for Therapy and Preventive Medicine
| | - S. A. Mironov
- National Medical Research Center for Therapy and Preventive Medicine
| | - M. A. Umetov
- Kh. M. BerbekovKabardino-Balkarian State University
| | - S. A. Berns
- National Medical Research Center for Therapy and Preventive Medicine
| | - I. S. Yavelov
- National Medical Research Center for Therapy and Preventive Medicine
| | - O. M. Drapkina
- National Medical Research Center for Therapy and Preventive Medicine
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Zhang YQ, Zhang WJ, Liu JH, Ji WZ. Effects of Chronic Hypoxic Environment on Cognitive Function and Neuroimaging Measures in a High-Altitude Population. Front Aging Neurosci 2022; 14:788322. [PMID: 35601614 PMCID: PMC9122256 DOI: 10.3389/fnagi.2022.788322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 03/31/2022] [Indexed: 11/13/2022] Open
Abstract
Objective This study aimed to investigate the effects of long-term hypoxic environment exposure on cognitive ability and neuroimaging characteristics in a highland population in China. Methods Health system workers in Maduo County (4,300 m above sea level) and Minhe County (1,700 m above sea level) were selected as research participants and divided into a high-altitude (HA) group and low-altitude (LA) group, respectively. Cognitive ability was assessed using the Montreal Cognitive Assessment (MoCA), Verbal Fluency Test (VFT), Symbol Digit Modalities Test (SDMT), Trail Making Test A and B (TMT), Digit Span Test (DST), and Rey Auditory Verbal Learning Test (RAVLT). All participants underwent a magnetic resonance imaging (MRI) scan, resting state functional MRI scan, and diffusion tensor imaging to clarify changes in regional gray matter (GM) volume, anisotropy index (FA), local consistency (ReHo), and low-frequency oscillation amplitude (ALFF). Results The HA group had significantly lower MoCA, DST, VFT, RAVLT, and TMT scores compared to the control group. No significant differences were found in SDMT score. Furthermore, compared to the LA group, the HA group had significantly lower GM density of the left olfactory cortex, right medial orbital superior frontal gyrus, bilateral insula, left globus pallidus, and temporal lobe (left superior temporal gyrus temporal pole, bilateral middle temporal gyrus temporal pole, and right middle temporal gyrus). In terms of FA, compared with the LA group, the HA group had lower values for the corpus callosum, corpus callosum knee, bilateral radiative corona, and left internal capsule. The HA group had lower ALFF values of the left cerebellum, left putamen, left orbital inferior frontal gyrus, and left precuneus, but higher ALFF values of the left fusiform gyrus, bilateral inferior temporal gyrus, left orbital superior frontal gyrus and medial superior frontal gyrus, compared to the LA group. There was no significant group difference in ReHo values. Conclusion Our findings suggest that a chronic hypoxic environment can induce extensive cognitive impairment. Decreased GM density in multiple brain regions, damaged nerve fibers, and unbalanced neuronal activity intensity in different brain regions may be the structural and functional basis of cognitive impairment due to hypoxia.
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Wang H, Li X, Li J, Gao Y, Li W, Zhao X, Wen R, Han J, Chen K, Liu L. Sleep, short-term memory, and mood states of volunteers with increasing altitude. Front Psychiatry 2022; 13:952399. [PMID: 36311491 PMCID: PMC9600328 DOI: 10.3389/fpsyt.2022.952399] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
PURPOSE This study sought to identify the changes and potential association between sleep characteristics and short-term memory, and mood states among volunteers at different altitudes and times. METHOD A total of 26 healthy volunteers were recruited from the PLA General Hospital, and we conducted a longitudinal prospective survey for over 1 year from November 2019 to April 2021. First, we collected demographic data, sleep parameters by overnight polysomnography (PSG), short-term memory by digit span test, and mood states by completing a questionnaire with a brief profile of mood states among participants in the plain (53 m). Then, we continuously followed them up to collect data in the 3rd month at an altitude of 1,650 m (on the 3rd month of the 1-year survey period), the 3rd month at an altitude of 4,000 m (on the 6th month of the 1-year survey period), and the 9th month at an altitude of 4,000 m (on the 12th month of the 1-year survey period). Multiple linear regression analysis was used to construct models between sleep parameters and short-term memory, and mood states. RESULTS The prevalence of sleep apnea syndrome (SAS) significantly increased with rising elevation (P < 0.01). The apnea-hypopnea index (AHI), the mean apnea time (MAT), the longest apnea time (LAT), and the duration of time with SaO2 < 90% (TSA90) were increased (P < 0.05), and the mean pulse oxygen saturation (MSpO2), the lowest pulse oxygen saturation (LSpO2), and heart rate were significantly decreased with increasing altitude (P < 0.05). Digit span scores were decreased with increasing altitude (P < 0.001). A negative mood was more severe and a positive mood increasingly faded with rising elevation (P < 0.001). Additionally, linear correlation analysis showed that higher AHI, LAT, and MAT were strongly associated with a greater decline in short-term memory (in the 3rd and 9th month at an altitude of 4,000 m, respectively: r s = -0.897, -0.901; r s = -0.691, -0.749; r s = -0.732, -0.794, P < 0.001), and also were strongly associated with more severe negative mood (in the 3rd month at altitudes of 1,650 m and 4,000 m, respectively: r s = 0.655, 0.715, 0.724; r s = 0.771, 0.638, 0.737, P < 0.000625). Multiple linear regression pointed out that AHI was a significant predictor of negative mood among people at different altitudes (in the 3rd month at an altitude of 1,650 m: TMD = 33.161 + 6.495*AHI; in the 3rd month at an altitude of 4,000 m: TMD = 74.247 + 1.589*AHI, P < 0.05). CONCLUSION SAS developed easily in high altitudes, most often in CSA (central sleep apnea, CSA). The sleep, short-term memory, and negative mood were significantly more damaged with elevation in volunteers. Sleep parameters were closely associated with short-term memory and mood states in volunteers at high altitudes; the higher the sleep parameters (AHI, LAT, and MAT) scores, the more significant the mood disorders and the more obvious impairment of short-term memory. AHI was a critical predictor of the negative mood of volunteers at different altitudes. This study provides evidence that could help with the prevention and control of sleep disorder, cognitive disorder, and negative mood among populations with high altitudes.
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Affiliation(s)
| | - Xueyan Li
- Gansu University of Chinese Medicine, Lanzhou, China
| | - Jianhua Li
- Department of Cardiology, The Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
| | - Yinghui Gao
- PKU-UPenn Sleep Center, Peking University International Hospital, Beijing, China
| | - Weihua Li
- Gansu Armed Police Corps Hospital, Lanzhou, China
| | - Xinke Zhao
- Sleep Center, The Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China
| | - Ruoqing Wen
- Gansu University of Chinese Medicine, Lanzhou, China
| | - Jiming Han
- Medical College, Yan'an University, Yan'an, China
| | - Kaibing Chen
- Sleep Center, The Affiliated Hospital of Gansu University of Chinese Medicine, Lanzhou, China
| | - Lin Liu
- Department of Respiratory and Critical Care Medicine of the Second Medical Center & National Clinical Research Center for Geriatric Diseases, Chinese PLA General Hospital, Beijing, China
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Association of Peripheral Plasma Neurotransmitters with Cognitive Performance in Chronic High-altitude Exposure. Neuroscience 2021; 463:97-107. [PMID: 33540052 DOI: 10.1016/j.neuroscience.2021.01.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 01/20/2021] [Accepted: 01/22/2021] [Indexed: 12/17/2022]
Abstract
Long-term living at high altitude causes significant impairment of cognitive function. Central neurotransmitters are potential mediators of cognitive performance. We aimed to determine whether there were significant associations between select peripheral plasma neurotransmitters and cognitive performance in humans with chronic high-altitude (HA) exposure and to determine the association between peripheral plasma neurotransmitters and brain neurotransmitters in rats after chronic hypobaric hypoxia (HH) exposure. We demonstrated that 3,4-dihydroxy-L-phenylalanine (DOPA), dopamine, serotonin, 5-hydroxyindole-3-acetic acid (5-HIAA) and GABA in the peripheral plasma were associated with cognitive performance in humans with HA exposure. Consistent with this result, peripheral plasma DOPA, dopamine, serotonin, 5-HIAA and glutamate were associated with brain neurotransmitter levels after chronic HH exposure in rats. These results provide experimental data indicating that neurotransmitter levels and cognitive performance are modified in chronic high-altitude exposure, with a possible causal effect.
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Yurkevicius BR, Bradbury KE, Nixon AC, Mitchell KM, Luippold AJ, Mayer TA, Alba BK, Salgado RM, Charkoudian N. Influence of Acetazolamide on Hand Strength and Manual Dexterity During a 30-h Simulated High Altitude Exposure. Mil Med 2020; 185:e1161-e1167. [PMID: 32175586 DOI: 10.1093/milmed/usaa041] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
INTRODUCTION High altitude missions pose significant challenges to Warfighter medical readiness and performance. Decreased circulating oxygen levels cause a decrease in exercise performance and can cause debilitating symptoms associated with acute mountain sickness, especially with rapid ascent. Acetazolamide (AZ) is known to minimize symptoms of acute mountain sickness, but it is unknown whether this medication alters hand strength and manual dexterity during altitude exposure. MATERIALS AND METHODS Ten male volunteers (22 ± 4 yr, 75.9 ± 13.7 kg, 174.9 ± 9.3 cm) participated in two separate 30 h simulated altitude exposures (496 mmHg, equivalent to 3,500 m, 20°C, 20% RH) in a hypobaric chamber. Participants were given either a placebo or 250 mg of AZ twice daily for 3.5 d (2 sea-level [SL] days + the 30 h altitude exposure) in a randomized, single-blind, crossover design. During SL and both altitude (ALT) exposures, hand function tests were performed, including hand grip and finger pinch strength tests, as well as the Purdue Pegboard (PP) and magazine loading tests to assess manual dexterity. Paired T tests and two-way repeated measure analysis of variance were used as appropriate to evaluate the effects of AZ and ALT. The value of p < 0.05 was accepted for statistical significance. RESULTS There were no influences of acute ALT exposure or AZ treatment on hand strength (eg, grip strength; SL: 39.2 ± 5.5 kg vs. ALT: 41.5 ± 6.9 kg, p > 0.05) or dexterity (eg, PPassembly; placebo: 35.5 ± 5.3 vs. AZ: 34.3 ± 4.6, p > 0.05) in our volunteers. Two dexterity tests (PPsum and magazine loading) showed improvements over time at ALT, regardless of treatment, where scores were improved after 10 h of exposure compared to at 1 h (eg, magazine loading: 56 ± 12 vs. 48 ± 10, p < 0.001). This pattern was not seen in the PPassembly test or any strength measurements. CONCLUSIONS Our results suggest that 500 mg/d of AZ does not influence hand strength or manual dexterity during a 30 h exposure to 3,500 m simulated ALT. Acute ALT exposure (1 h) did not influence dexterity or strength, although some measures of dexterity showed improvements as exposure time increased. We conclude that use of AZ to optimize medical readiness at ALT is unlikely to impair the Warfighter's ability to complete mission tasks that depend on hand function.
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Affiliation(s)
- Beau R Yurkevicius
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA.,Oak Ridge Institute for Science and Education, 1299 Bethel Valley Road, Oak Ridge, TN 37830, USA
| | - Karleigh E Bradbury
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Adam C Nixon
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Katherine M Mitchell
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Adam J Luippold
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Thomas A Mayer
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA.,Oak Ridge Institute for Science and Education, 1299 Bethel Valley Road, Oak Ridge, TN 37830, USA
| | - Billie K Alba
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Roy M Salgado
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
| | - Nisha Charkoudian
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, 10 General Greene Avenue, Natick, MA 01760, USA
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20
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Guo Z, Fan C, Li T, Gesang L, Yin W, Wang N, Weng X, Gong Q, Zhang J, Wang J. Neural network correlates of high-altitude adaptive genetic variants in Tibetans: A pilot, exploratory study. Hum Brain Mapp 2020; 41:2406-2430. [PMID: 32128935 PMCID: PMC7267913 DOI: 10.1002/hbm.24954] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 01/16/2020] [Accepted: 02/09/2020] [Indexed: 02/05/2023] Open
Abstract
Although substantial progress has been made in the identification of genetic substrates underlying physiology, neuropsychology, and brain organization, the genotype–phenotype associations remain largely unknown in the context of high‐altitude (HA) adaptation. Here, we related HA adaptive genetic variants in three gene loci (EGLN1, EPAS1, and PPARA) to interindividual variance in a set of physiological characteristics, neuropsychological tests, and topological attributes of large‐scale structural and functional brain networks in 135 indigenous Tibetan highlanders. Analyses of individual HA adaptive single‐nucleotide polymorphisms (SNPs) revealed that specific SNPs selectively modulated physiological characteristics (erythrocyte level, ratio between forced expiratory volume in the first second to forced vital capacity, arterial oxygen saturation, and heart rate) and structural network centrality (the left anterior orbital gyrus) with no effects on neuropsychology or functional brain networks. Further analyses of genetic adaptive scores, which summarized the overall degree of genetic adaptation to HA, revealed significant correlations only with structural brain networks with respect to local interconnectivity of the whole networks, intermodule communication between the right frontal and parietal module and the left occipital module, nodal centrality in several frontal regions, and connectivity strength of a subnetwork predominantly involving in intramodule edges in the right temporal and occipital module. Moreover, the associations were dependent on gene loci, weight types, or topological scales. Together, these findings shed new light on genotype–phenotype interactions under HA hypoxia and have important implications for developing new strategies to optimize organism and tissue responses to chronic hypoxia induced by extreme environments or diseases.
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Affiliation(s)
- Zhiyue Guo
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Cunxiu Fan
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, Fujian, China.,Department of Neurology, Shanghai Changhai Hospital, Navy Medical University, Shanghai, China
| | - Ting Li
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Luobu Gesang
- Institute of High Altitude Medicine, Tibet Autonomous Region People's Hospital, Lhasa, Tibet Autonomous Region, China
| | - Wu Yin
- Department of Radiology, Tibet Autonomous Region People's Hospital, Lhasa, Tibet Autonomous Region, China
| | - Ningkai Wang
- Department of Psychology, Hangzhou Normal University, Hangzhou, China
| | - Xuchu Weng
- Guangdong Key Laboratory of Mental Health and Cognitive Science, Center for Studies of Psychological Application, South China Normal University, Institute for Brain Research and Rehabilitation, Guangzhou, China
| | - Qiyong Gong
- Huaxi Magnetic Resonance Research Center, West China Hospital, Sichuan University, Chengdu, China
| | - Jiaxing Zhang
- Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen, Fujian, China
| | - Jinhui Wang
- Guangdong Key Laboratory of Mental Health and Cognitive Science, Center for Studies of Psychological Application, South China Normal University, Institute for Brain Research and Rehabilitation, Guangzhou, China
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21
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Individual chronic mountain sickness symptom is an early warning sign of cognitive impairment. Physiol Behav 2020; 214:112748. [DOI: 10.1016/j.physbeh.2019.112748] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/18/2019] [Accepted: 11/22/2019] [Indexed: 12/14/2022]
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22
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Tavares-Silva E, Donatto FF, Medeiros RMV, Santos SA, Caris AV, Thomatieli-Santos RV. Carbohydrate supplementation and psychophysiological responses during moderate exercise in hypoxia. J Int Soc Sports Nutr 2020; 17:3. [PMID: 31906976 PMCID: PMC6945642 DOI: 10.1186/s12970-019-0331-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 12/12/2019] [Indexed: 12/14/2022] Open
Abstract
Background Rating of Perceived Exertion (RPE) is a subjective scale to monitor overload and fatigue during exercise. Hypoxia may worsen the perception of fatigue, compromising the self-reported perception of effort and increasing RPE. The objective was to evaluate the effects of carbohydrate (CHO) supplementation on RPE during exercise in hypoxia simulating 4200 m. Methods Eight male physically active volunteers performed two exercises at 50% VO2peak and 1% slope: exercise in hypoxia + placebo or exercise in hypoxia + CHO (6% maltodextrin) with supplementation at 20, 40, and 60 min during exercise. Oxygen Saturation (SaO2%) was assessed at baseline and after exercise, while RPE and HR were measured each 10 min during the trial. Results SaO2% decreased after exercise in both conditions of hypoxia compared to rest. The RPE did not differ between groups. However, the RPE increased in hypoxia after 20 min of exercise in relation to 10 min. The Area Under the Curve (AUC) of RPE was lower in hypoxia + CHO compared to hypoxia. The AUC of the HR/RPE ratio in the hypoxia + CHO group was higher in relation to hypoxia. Conclusions Our results indicate that CHO supplementation does not change RPE induced by 60 min of exercise at 50% VO2peak in hypoxia equivalent to 4200 m at the different times analyzed. However, in hypoxia + CHO the (AUC)-60 min of total RPE decreased during exercise, while the heart rate/RPE ratio improved, indicating lower RPE in the hypoxic environment.
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Affiliation(s)
- E Tavares-Silva
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - F F Donatto
- Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil
| | - R M V Medeiros
- Centro Universitário do Rio Grande do Norte (UNI-RN), Natal, Brazil
| | - S A Santos
- Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil
| | - A V Caris
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil
| | - R V Thomatieli-Santos
- Department of Psychobiology, Universidade Federal de São Paulo, São Paulo, Brazil. .,Department of Bioscience, Universidade Federal de São Paulo, Rua Silva Jardim, 136 - Vila Mathias, Santos, SP, 11015-020, Brazil.
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23
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Chronic Exposure to High Altitude: Synaptic, Astroglial and Memory Changes. Sci Rep 2019; 9:16406. [PMID: 31712561 PMCID: PMC6848138 DOI: 10.1038/s41598-019-52563-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 10/11/2019] [Indexed: 11/18/2022] Open
Abstract
Long-term operations carried out at high altitude (HA) by military personnel, pilots, and astronauts may trigger health complications. In particular, chronic exposure to high altitude (CEHA) has been associated with deficits in cognitive function. In this study, we found that mice exposed to chronic HA (5000 m for 12 weeks) exhibited deficits in learning and memory associated with hippocampal function and were linked with changes in the expression of synaptic proteins across various regions of the brain. Specifically, we found decreased levels of synaptophysin (SYP) (p < 0.05) and spinophilin (SPH) (p < 0.05) in the olfactory cortex, post synaptic density−95 (PSD-95) (p < 0.05), growth associated protein 43 (GAP43) (p < 0.05), glial fibrillary acidic protein (GFAP) (p < 0.05) in the cerebellum, and SYP (p < 0.05) and PSD-95 (p < 0.05) in the brainstem. Ultrastructural analyses of synaptic density and morphology in the hippocampus did not reveal any differences in CEHA mice compared to SL mice. Our data are novel and suggest that CEHA exposure leads to cognitive impairment in conjunction with neuroanatomically-based molecular changes in synaptic protein levels and astroglial cell marker in a region specific manner. We hypothesize that these new findings are part of highly complex molecular and neuroplasticity mechanisms underlying neuroadaptation response that occurs in brains when chronically exposed to HA.
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24
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Ando S, Komiyama T, Sudo M, Higaki Y, Ishida K, Costello JT, Katayama K. The interactive effects of acute exercise and hypoxia on cognitive performance: A narrative review. Scand J Med Sci Sports 2019; 30:384-398. [PMID: 31605635 DOI: 10.1111/sms.13573] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 09/09/2019] [Accepted: 10/04/2019] [Indexed: 12/13/2022]
Abstract
Acute moderate intensity exercise has been shown to improve cognitive performance. In contrast, hypoxia is believed to impair cognitive performance. The detrimental effects of hypoxia on cognitive performance are primarily dependent on the severity and duration of exposure. In this review, we describe how acute exercise under hypoxia alters cognitive performance, and propose that the combined effects of acute exercise and hypoxia on cognitive performance are mainly determined by interaction among exercise intensity and duration, the severity of hypoxia, and duration of exposure to hypoxia. We discuss the physiological mechanism(s) of the interaction and suggest that alterations in neurotransmitter function, cerebral blood flow, and possibly cerebral metabolism are the primary candidates that determine cognitive performance when acute exercise is combined with hypoxia. Furthermore, acclimatization appears to counteract impaired cognitive performance during prolonged exposure to hypoxia although the precise physiological mechanism(s) responsible for this amelioration remain to be elucidated. This review has implications for sporting, occupational, and recreational activities at terrestrial high altitude where cognitive performance is essential. Further studies are required to understand physiological mechanisms that determine cognitive performance when acute exercise is performed in hypoxia.
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Affiliation(s)
- Soichi Ando
- Graduate School of Informatics and Engineering, The University of Electro-Communications, Tokyo, Japan
| | - Takaaki Komiyama
- Center for Education in Liberal Arts and Sciences, Osaka University, Osaka, Japan
| | - Mizuki Sudo
- Meiji Yasuda Life Foundation of Health and Welfare, Tokyo, Japan
| | - Yasuki Higaki
- Faculty of Sports Science, Fukuoka University, Fukuoka, Japan
| | - Koji Ishida
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
| | - Joseph T Costello
- Extreme Environments Laboratory, Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, UK
| | - Keisho Katayama
- Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Japan
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25
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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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26
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Lebret M, Wuyam B, Bertrand D, Chaudot C, Pépin JL, Borel JC. Effectiveness of a lightweight portable auto-CPAP device for the treatment of sleep apnea during high altitude stages of the Dakar Rally: a case report. Sleep Sci 2018; 11:123-126. [PMID: 30083301 PMCID: PMC6056067 DOI: 10.5935/1984-0063.20180023] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sleep-related breathing disturbances are exacerbated at altitude in patients with Obstructive Sleep Apnea (OSA). The objective of this case report was to determine if a portable auto-CPAP device effectively treated sleep apnea across different altitudes. We report the severity of sleep apnea from 60 to 12,000 feet high in a man with severe OSA (Apnea Hypopnea Index at diagnosis = 60 events/hour) during the 2017 Dakar rally over the Andes mountains. The man was equipped with a lightweight portable auto-CPAP device with a narrow window [6-8 cmH2O]. Pressures delivered and corresponding residual events were assessed at different altitudes. The 95th percentile pressure reached the maximal set pressure at the highest altitudes, and residual AHI increased from 5 events/hour to 45 events/hour at the highest altitudes. Potential mechanisms behind the development of central apnea, and optimal clinical management at altitude are discussed in the light of the findings.
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Affiliation(s)
- Marius Lebret
- Inserm U1042, HP2 laboratory - Grenoble - Isère - França.,Agir a dom., Agir a dom. - Meylan - Isère - França
| | - Bernard Wuyam
- Inserm U1042, HP2 laboratory - Grenoble - Isère - França.,Thorax and vessels division Grenoble Alpes University Hospital, Sleep Laboratory and Exercise Physiology - Grenoble - Isère - França
| | - Dominique Bertrand
- Pulmonary and Sleep clinic, Pulmonary and sleep clinic - St Ismier - isère - França
| | | | - Jean-Louis Pépin
- Inserm U1042, HP2 laboratory - Grenoble - Isère - França.,Thorax and vessels division Grenoble Alpes University Hospital, Sleep Laboratory and Exercise Physiology - Grenoble - Isère - França
| | - Jean-Christian Borel
- Inserm U1042, HP2 laboratory - Grenoble - Isère - França.,Agir a dom., Agir a dom. - Meylan - Isère - França.,Thorax and vessels division Grenoble Alpes University Hospital, Sleep Laboratory and Exercise Physiology - Grenoble - Isère - França
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27
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Caldwell HG, Coombs GB, Tymko MM, Nowak-Flück D, Ainslie PN. Severity-dependent influence of isocapnic hypoxia on reaction time is independent of neurovascular coupling. Physiol Behav 2018; 188:262-269. [PMID: 29458114 DOI: 10.1016/j.physbeh.2018.02.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/16/2018] [Accepted: 02/16/2018] [Indexed: 12/23/2022]
Abstract
With exposure to acute normobaric hypoxia, global cerebral oxygen delivery is maintained via increases in cerebral blood flow (CBF); therefore, regional and localized changes in oxygen tension may explain neurocognitive impairment. Neurovascular coupling (NVC) is the close temporal and regional relationship of CBF to changes in neural activity and may aid in explaining the localized CBF response with cognitive activation. High-altitude related cognitive impairment is likely affected by hypocapnic cerebral vasoconstriction that may influence regional CBF regulation independent of hypoxia. We assessed neurocognition and NVC following 30 min of acute exposure to isocapnic hypoxia (decreased partial pressure of end-tidal oxygen; PETO2) during moderate hypoxia (MOD HX; 55 mm Hg PETO2), and severe hypoxia (SEV HX; 45 mm Hg PETO2) in 10 healthy individuals (25.5 ± 3.3 yrs). Transcranial Doppler ultrasound was used to assess mean posterior and middle cerebral blood velocity (PCAv and MCAv, respectively) and neurocognitive performance was assessed via validated computerized tests. The main finding was that reaction time (i.e., kinesthetic and visual-motor ability via Stroop test) was selectively impaired in SEV HX (-4.6 ± 5.2%, P = 0.04), but not MOD HX, while complex cognitive performance (e.g., psychomotor speed, cognitive flexibility, processing speed, executive function, and motor speed) was unaffected with hypoxia (P > 0.05). Additionally, severity of hypoxia had no effect on NVC (PCAv CON vs. SEV HX relative peak response 13.7 ± 6.4% vs. 16.2 ± 11.5%, P = 0.71, respectively). In summary, severe isocapnic hypoxia impaired reaction time, but not complex cognitive performance or NVC. These findings have implications for recreational and military personnel who may experience acute hypoxia.
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Affiliation(s)
- Hannah G Caldwell
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, Canada.
| | - Geoff B Coombs
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, Canada
| | - Michael M Tymko
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, Canada
| | - Daniela Nowak-Flück
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, Canada
| | - Philip N Ainslie
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Okanagan, Kelowna, Canada
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28
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Caldwell HG, Ainslie PN, Ellis LA, Phillips AA, Flück D. Stability in neurovascular function at 3800 m. Physiol Behav 2017; 182:62-68. [DOI: 10.1016/j.physbeh.2017.09.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 01/19/2023]
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29
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Hu S, Shi J, Xiong W, Li W, Fang L, Feng H. Oxiracetam or fastigial nucleus stimulation reduces cognitive injury at high altitude. Brain Behav 2017; 7:e00762. [PMID: 29075554 PMCID: PMC5651378 DOI: 10.1002/brb3.762] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/04/2017] [Accepted: 06/07/2017] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Cognitive impairment is common in people travelling to high altitude. Oxiracetam and electrical stimulation of cerebellar fastigial nucleus may have beneficial impacts. This study was to investigate the effects of preconditioning with Oxiracetam or fastigial nucleus stimulation (FNS) on cognitive decline following the ascension to high altitude. METHODS The study was conducted on 60 male military voluntary members who were divided into control group, Oxiracetam group, and fastigial nucleus stimulation group. Transcranial doppler sonography, auditory evoked potential, electroencephalogram (EEG), and cognitive assessments were performed. RESULTS People could still suffer cognitive dysfunction at 4,000 m high altitude despite that they have lived at 1,800 m altitude for several years. The 4,000 m altitude environment also prolonged P300 and N200 latencies. Both Oxiracetam and FNS improved cognitive function, reduced the prolonged latencies of Event Related Potentials (P300 and N200), decreased the average velocity of brain arteries, and enhanced EEG power spectral entropy at 4,000 m altitude. CONCLUSIONS Neurophysiological evidences suggest the underlying mechanism of cognitive impairments. Both Oxiracetam and FNS can reduce cognitive decline post arrival at high altitude. They could be a potential pretreatment method for cognitive dysfunction resulted from high altitude.
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Affiliation(s)
- ShengLi Hu
- Department of Neurosurgery Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
| | - JianTao Shi
- Department of Neurosurgery Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
| | - Wei Xiong
- Department of Respiration Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
| | - WeiNa Li
- Department of Neurosurgery Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
| | - LiChao Fang
- Department of Laboratory Medicine Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
| | - Hua Feng
- Department of Neurosurgery Southwest Hospital Collaborative Innovation Center for Brain Science Third Military Medical University Chong Qing China
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Abstract
Objective: To screen out psychiatric ‘cases’ and find the frequency of anxiety and depression symptoms in military volunteers performing duties at very high altitudes in the Karakoram ranges of Pakistan. Methods: This was a descriptive study lasting from Jan 2015 to June 2015, on volunteers serving at very high altitude, using General Health Questionnaire-12 (GHQ-12) and Hospital Anxiety and Depression Scale (HADS), Urdu versions. Analysis involved descriptive, inferential techniques and Bonferroni test. Demographic variables were compared to the scores. Results: A high percentage of the military volunteers screened positive for psychiatric ‘caseness’ and symptoms of anxiety and depression; mostly in the mild to moderate range, while very few of them reported severe symptoms. Demographic variables such as marital status, number of children, positive family psychiatric history, past medical history, duration at high altitude and educational levels were found to be significant risk factors for developing symptoms of anxiety and depression. Conclusions: Individuals performing duties at very high altitude, experience symptoms of anxiety and depression, their demographics are important in understanding their emotional problems.
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Affiliation(s)
- Sabih Ahmad
- Dr. Sabih Ahmad, FCPS. Department of Psychiatry, Consultant Psychiatrist, Combined Military Hospital, Gilgit, Pakistan
| | - Sadiq Hussain
- Dr. Sadiq Hussain, PhD. Department of Behavioral Sciences, Head of Department, Karakorum International University, Gilgit, Pakistan
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Effect of acute hypoxia on cognition: A systematic review and meta-regression analysis. Neurosci Biobehav Rev 2017; 74:225-232. [PMID: 28111267 DOI: 10.1016/j.neubiorev.2017.01.019] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 12/20/2022]
Abstract
A systematic meta-regression analysis of the effects of acute hypoxia on the performance of central executive and non-executive tasks, and the effects of the moderating variables, arterial partial pressure of oxygen (PaO2) and hypobaric versus normobaric hypoxia, was undertaken. Studies were included if they were performed on healthy humans; within-subject design was used; data were reported giving the PaO2 or that allowed the PaO2 to be estimated (e.g. arterial oxygen saturation and/or altitude); and the duration of being in a hypoxic state prior to cognitive testing was ≤6days. Twenty-two experiments met the criteria for inclusion and demonstrated a moderate, negative mean effect size (g=-0.49, 95% CI -0.64 to -0.34, p<0.001). There were no significant differences between central executive and non-executive, perception/attention and short-term memory, tasks. Low (35-60mmHg) PaO2 was the key predictor of cognitive performance (R2=0.45, p<0.001) and this was independent of whether the exposure was in hypobaric hypoxic or normobaric hypoxic conditions.
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32
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Abstract
CONTEXT Athletes at different skill levels perform strenuous physical activity at high altitude for a variety of reasons. Multiple team and endurance events are held at high altitude and may place athletes at increased risk for developing acute high altitude illness (AHAI). Training at high altitude has been a routine part of preparation for some of the high level athletes for a long time. There is a general belief that altitude training improves athletic performance for competitive and recreational athletes. EVIDENCE ACQUISITION A review of relevant publications between 1980 and 2015 was completed using PubMed and Google Scholar. STUDY DESIGN Clinical review. LEVEL OF EVIDENCE Level 3. RESULTS AHAI is a relatively uncommon and potentially serious condition among travelers to altitudes above 2500 m. The broad term AHAI includes several syndromes such as acute mountain sickness (AMS), high altitude pulmonary edema (HAPE), and high altitude cerebral edema (HACE). Athletes may be at higher risk for developing AHAI due to faster ascent and more vigorous exertion compared with nonathletes. Evidence regarding the effects of altitude training on athletic performance is weak. The natural live high, train low altitude training strategy may provide the best protocol for enhancing endurance performance in elite and subelite athletes. High altitude sports are generally safe for recreational athletes, but they should be aware of their individual risks. CONCLUSION Individualized and appropriate acclimatization is an essential component of injury and illness prevention.
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Affiliation(s)
- Morteza Khodaee
- Department of Family Medicine, University of Colorado School of Medicine, Denver, Colorado
- Morteza Khodaee, MD, MPH, Department of Family Medicine, University of Colorado School of Medicine, AFW Clinic, 3055 Roslyn Street, Denver, CO 80238 ()
| | - Heather L. Grothe
- Department of Family Medicine, University of Colorado School of Medicine, Denver, Colorado
| | - Jonathan H. Seyfert
- Department of Family Medicine, University of Colorado School of Medicine, Denver, Colorado
| | - Karin VanBaak
- Department of Family Medicine, University of Colorado School of Medicine, Denver, Colorado
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de Aquino-Lemos V, Santos RVT, Antunes HKM, Lira FS, Luz Bittar IG, Caris AV, Tufik S, de Mello MT. Acute physical exercise under hypoxia improves sleep, mood and reaction time. Physiol Behav 2016; 154:90-9. [DOI: 10.1016/j.physbeh.2015.10.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 10/15/2015] [Accepted: 10/27/2015] [Indexed: 01/20/2023]
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Silva-Urra JA, Núñez-Espinosa CA, Niño-Mendez OA, Gaitán-Peñas H, Altavilla C, Toro-Salinas A, Torrella JR, Pagès T, Javierre CF, Behn C, Viscor G. Circadian and Sex Differences After Acute High-Altitude Exposure: Are Early Acclimation Responses Improved by Blue Light? Wilderness Environ Med 2015; 26:459-71. [PMID: 26254125 DOI: 10.1016/j.wem.2015.06.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 04/30/2015] [Accepted: 06/11/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVE The possible effects of blue light during acute hypoxia and the circadian rhythm on several physiological and cognitive parameters were studied. METHODS Fifty-seven volunteers were randomly assigned to 2 groups: nocturnal (2200-0230 hours) or diurnal (0900-1330 hours) and exposed to acute hypoxia (4000 m simulated altitude) in a hypobaric chamber. The participants were illuminated by blue LEDs or common artificial light on 2 different days. During each session, arterial oxygen saturation (Spo2), blood pressure, heart rate variability, and cognitive parameters were measured at sea level, after reaching the simulated altitude of 4000 m, and after 3 hours at this altitude. RESULTS The circadian rhythm caused significant differences in blood pressure and heart rate variability. A 4% to 9% decrease in waking nocturnal Spo2 under acute hypoxia was observed. Acute hypoxia also induced a significant reduction (4%-8%) in systolic pressure, slightly more marked (up to 13%) under blue lighting. Women had significantly increased systolic (4%) and diastolic (12%) pressures under acute hypoxia at night compared with daytime pressure; this was not observed in men. Some tendencies toward better cognitive performance (d2 attention test) were seen under blue illumination, although when considered together with physiological parameters and reaction time, there was no conclusive favorable effect of blue light on cognitive fatigue suppression after 3 hours of acute hypobaric hypoxia. CONCLUSIONS It remains to be seen whether longer exposure to blue light under hypobaric hypoxic conditions would induce favorable effects against fatigue.
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Affiliation(s)
- Juan A Silva-Urra
- Departamento Biomédico, Universidad de Antofagasta, Antofagasta, Chile
| | | | - Oscar A Niño-Mendez
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, Barcelona, Spain
| | | | | | | | | | | | - Casimiro F Javierre
- Departament de Ciències Fisiològiques II, Universitat de Barcelona, Barcelona, Spain
| | - Claus Behn
- Laboratorio de Ambientes Extremos (ICBM), Universidad de Chile, Santiago de Chile, Chile
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Hypoxia-inducible factor-1α upregulation in microglia following hypoxia protects against ischemia-induced cerebral infarction. Neuroreport 2015; 25:1122-8. [PMID: 25089804 DOI: 10.1097/wnr.0000000000000236] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Activated microglia were considered to be the toxic inflammatory mediators that induce neuron degeneration after brain ischemia. Hypoxia can enhance the expression of hypoxia-inducible factor-1α (HIF-1α) in microglia and cause microglial activation. However, intermittent hypoxia has been reported recently to be capable of protecting the body from myocardial ischemia. We established a high-altitude environment as the hypoxic condition in this study. The hypoxic condition displayed a neuroprotective effect after brain ischemia, and mice exposed to this condition presented better neurological performance and smaller infarct size. At the same time, a high level of HIF-1α, low level of isoform of nitric oxide synthase, and a reduction in microglial activation were also seen in ischemic focus of hypoxic mice. However, this neuroprotective effect could be blocked by 2-methoxyestradiol, the HIF-1α inhibitor. Our finding suggested that HIF-1α expression was involved in microglial activation in vitro and was regulated by oxygen supply. The microglia were inactivated by re-exposure to hypoxia, which might be due to overexpression of HIF-1α. These results indicated that hypoxic conditions can be exploited to achieve maximum neuroprotection after brain ischemia. This mechanism possibly lies in microglial inactivation through regulation of the expression of HIF-1α.
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