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Dubayle D, Vanden-Bossche A, Peixoto T, Morel JL. Hypergravity Increases Blood-Brain Barrier Permeability to Fluorescent Dextran and Antisense Oligonucleotide in Mice. Cells 2023; 12:cells12050734. [PMID: 36899870 PMCID: PMC10000817 DOI: 10.3390/cells12050734] [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: 01/26/2023] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 03/03/2023] Open
Abstract
The earliest effect of spaceflight is an alteration in vestibular function due to microgravity. Hypergravity exposure induced by centrifugation is also able to provoke motion sickness. The blood-brain barrier (BBB) is the crucial interface between the vascular system and the brain to ensure efficient neuronal activity. We developed experimental protocols of hypergravity on C57Bl/6JRJ mice to induce motion sickness and reveal its effects on the BBB. Mice were centrifuged at 2× g for 24 h. Fluorescent dextrans with different sizes (40, 70 and 150 kDa) and fluorescent antisense oligonucleotides (AS) were injected into mice retro-orbitally. The presence of fluorescent molecules was revealed by epifluorescence and confocal microscopies in brain slices. Gene expression was evaluated by RT-qPCR from brain extracts. Only the 70 kDa dextran and AS were detected in the parenchyma of several brain regions, suggesting an alteration in the BBB. Moreover, Ctnnd1, Gja4 and Actn1 were upregulated, whereas Jup, Tjp2, Gja1, Actn2, Actn4, Cdh2 and Ocln genes were downregulated, specifically suggesting a dysregulation in the tight junctions of endothelial cells forming the BBB. Our results confirm the alteration in the BBB after a short period of hypergravity exposure.
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Affiliation(s)
- David Dubayle
- CNRS, INCC, UMR 8002, Université Paris Cité, F-75006 Paris, France
- Correspondence: (D.D.); (J.-L.M.)
| | - Arnaud Vanden-Bossche
- INSERM, SAINBIOSE U1059, Mines Saint-Etienne, Université Jean Monnet Saint-Étienne, F-42023 Saint-Étienne, France
| | - Tom Peixoto
- University Bordeaux, CNRS, INCIA, UMR 5287, F-33000 Bordeaux, France
| | - Jean-Luc Morel
- University Bordeaux, CNRS, INCIA, UMR 5287, F-33000 Bordeaux, France
- University Bordeaux, CNRS, IMN, UMR 5293, F-33000 Bordeaux, France
- Correspondence: (D.D.); (J.-L.M.)
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Roy-O'Reilly M, Mulavara A, Williams T. A review of alterations to the brain during spaceflight and the potential relevance to crew in long-duration space exploration. NPJ Microgravity 2021; 7:5. [PMID: 33594073 PMCID: PMC7887220 DOI: 10.1038/s41526-021-00133-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 01/13/2021] [Indexed: 02/06/2023] Open
Abstract
During spaceflight, the central nervous system (CNS) is exposed to a complex array of environmental stressors. However, the effects of long-duration spaceflight on the CNS and the resulting impact to crew health and operational performance remain largely unknown. In this review, we summarize the current knowledge regarding spaceflight-associated changes to the brain as measured by magnetic resonance imaging, particularly as they relate to mission duration. Numerous studies have reported macrostructural changes to the brain after spaceflight, including alterations in brain position, tissue volumes and cerebrospinal fluid distribution and dynamics. Changes in brain tissue microstructure and connectivity were also described, involving regions related to vestibular, cerebellar, visual, motor, somatosensory and cognitive function. Several alterations were also associated with exposure to analogs of spaceflight, providing evidence that brain changes likely result from cumulative exposure to multiple independent environmental stressors. Whereas several studies noted that changes to the brain become more pronounced with increasing mission duration, it remains unclear if these changes represent compensatory phenomena or maladaptive dysregulations. Future work is needed to understand how spaceflight-associated changes to the brain affect crew health and performance, with the goal of developing comprehensive monitoring and countermeasure strategies for future long-duration space exploration.
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Affiliation(s)
- Meaghan Roy-O'Reilly
- Department of Neurology, University of Texas Health Science Center, Houston, TX, USA.
- Department of Medicine, Stanford University Medical Center, Stanford, CA, USA.
| | | | - Thomas Williams
- National Aeronautics and Space Administration, Johnson Space Center, Houston, TX, USA
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3
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Janigro D, Bailey DM, Lehmann S, Badaut J, O'Flynn R, Hirtz C, Marchi N. Peripheral Blood and Salivary Biomarkers of Blood-Brain Barrier Permeability and Neuronal Damage: Clinical and Applied Concepts. Front Neurol 2021; 11:577312. [PMID: 33613412 PMCID: PMC7890078 DOI: 10.3389/fneur.2020.577312] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/01/2020] [Indexed: 12/12/2022] Open
Abstract
Within the neurovascular unit (NVU), the blood–brain barrier (BBB) operates as a key cerebrovascular interface, dynamically insulating the brain parenchyma from peripheral blood and compartments. Increased BBB permeability is clinically relevant for at least two reasons: it actively participates to the etiology of central nervous system (CNS) diseases, and it enables the diagnosis of neurological disorders based on the detection of CNS molecules in peripheral body fluids. In pathological conditions, a suite of glial, neuronal, and pericyte biomarkers can exit the brain reaching the peripheral blood and, after a process of filtration, may also appear in saliva or urine according to varying temporal trajectories. Here, we specifically examine the evidence in favor of or against the use of protein biomarkers of NVU damage and BBB permeability in traumatic head injury, including sport (sub)concussive impacts, seizure disorders, and neurodegenerative processes such as Alzheimer's disease. We further extend this analysis by focusing on the correlates of human extreme physiology applied to the NVU and its biomarkers. To this end, we report NVU changes after prolonged exercise, freediving, and gravitational stress, focusing on the presence of peripheral biomarkers in these conditions. The development of a biomarker toolkit will enable minimally invasive routines for the assessment of brain health in a broad spectrum of clinical, emergency, and sport settings.
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Affiliation(s)
- Damir Janigro
- Department of Physiology Case Western Reserve University, Cleveland, OH, United States.,FloTBI Inc., Cleveland, OH, United States
| | - Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Wales, United Kingdom
| | - Sylvain Lehmann
- IRMB, INM, UFR Odontology, University Montpellier, INSERM, CHU Montpellier, CNRS, Montpellier, France
| | - Jerome Badaut
- Brain Molecular Imaging Lab, CNRS UMR 5287, INCIA, University of Bordeaux, Bordeaux, France
| | - Robin O'Flynn
- IRMB, INM, UFR Odontology, University Montpellier, INSERM, CHU Montpellier, CNRS, Montpellier, France
| | - Christophe Hirtz
- IRMB, INM, UFR Odontology, University Montpellier, INSERM, CHU Montpellier, CNRS, Montpellier, France
| | - Nicola Marchi
- Cerebrovascular and Glia Research, Department of Neuroscience, Institute of Functional Genomics (UMR 5203 CNRS-U 1191 INSERM, University of Montpellier), Montpellier, France
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Bailey DM, Lanéelle D, Trihan JE, Marchi N, Stacey BS, Tamiya K, Washio T, Tuaillon E, Hirtz C, Lehmann S, Ogoh S, Normand H. Gravitational Transitions Increase Posterior Cerebral Perfusion and Systemic Oxidative-nitrosative Stress: Implications for Neurovascular Unit Integrity. Neuroscience 2020; 441:142-160. [PMID: 32502571 DOI: 10.1016/j.neuroscience.2020.05.048] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 05/22/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022]
Abstract
The present study examined if repeated bouts of micro- and hypergravity during parabolic flight (PF) alter structural integrity of the neurovascular unit (NVU) subsequent to free radical-mediated changes in regional cerebral perfusion. Six participants (5♂, 1♀) aged 29 ± 11 years were examined before, during and after a 3 h PF and compared to six sex and age-matched (27 ± 6 years) normogravity controls. Blood flow was measured in the anterior (middle cerebral artery, MCA; internal carotid artery, ICA) and posterior (vertebral artery, VA) circulation (duplex ultrasound) in-flight over the course of 15 parabolas. Venous blood was assayed for free radicals (electron paramagnetic resonance spectroscopy), nitric oxide (NO, ozone-based chemiluminescence) and NVU integrity (chemiluminescence/ELISA) in normogravity before and after exposure to 31 parabolas. While MCA velocity did not change (P > 0.05), a selective increase in VA flow was observed during the most marked gravitational transition from micro- to hypergravity (P < 0.05). Increased oxidative-nitrosative stress defined by a free radical-mediated reduction in NO and elevations in glio-vascular GFAP and S100ß were observed after PF (P < 0.05), the latter proportional to the increase in VA flow (r = 0.908, P < 0.05). In contrast, biomarkers of neuronal-axonal damage (neuron-specific enolase, neurofilament light-chain, ubiquitin carboxy-terminal hydrolase L1 and tau) did not change (P > 0.05). Collectively, these findings suggest that the cumulative effects of repeated gravitational transitions may promote minor blood-brain barrier disruption, potentially related to the combined effects of haemodynamic (posterior cerebral hyperperfusion) and molecular (systemic oxidative-nitrosative) stress.
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Affiliation(s)
- Damian M Bailey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, UK.
| | - Damien Lanéelle
- Service de Médecine Vasculaire, Centre Hospitalo-Universitaire, Caen, France; UNICAEN, INSERM, COMETE, GIP CYCERON, Normandie University, Caen, France
| | - Jean-Eudes Trihan
- Service de Médecine Vasculaire, Centre Hospitalier Universitaire de Poitiers, Poitiers, France
| | - Nicola Marchi
- UMR, Laboratory of Cerebrovascular and Glia Research, Department of Neuroscience, Institute of Functional Genomics (CNRS Unit Mixte de Recherche 5203; INSERM U1191), University of Montpellier, France
| | - Benjamin S Stacey
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, UK
| | - Kazuki Tamiya
- Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
| | - Takuro Washio
- Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
| | - Edouard Tuaillon
- Unit Mixte de Recherche, INSERM l'Etablissement Français du Sang, University of Montpellier 1, Montpellier, France
| | - Christophe Hirtz
- LBPC-PPC, University of Montpellier, Institute of Regenerative Medicine-Biotherapy IRMB, Centre Hospitalier Universitaire de Montpellier, INSERM, Montpellier, France
| | - Sylvain Lehmann
- LBPC-PPC, University of Montpellier, Institute of Regenerative Medicine-Biotherapy IRMB, Centre Hospitalier Universitaire de Montpellier, INSERM, Montpellier, France
| | - Shigehiko Ogoh
- Neurovascular Research Laboratory, Faculty of Life Sciences and Education, University of South Wales, Glamorgan, UK; Department of Biomedical Engineering, Toyo University, Kawagoe-Shi, Saitama, Japan
| | - Hervé Normand
- UNICAEN, INSERM, COMETE, GIP CYCERON, Normandie University, Caen, France; UNICAEN, COMETE, Caen, France; INSERM, U 1075 COMETE, Caen, France; Department of Clinical Physiology, Centre Hospitalier Universitaire de Caen, Caen, France
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5
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Clément GR, Boyle RD, George KA, Nelson GA, Reschke MF, Williams TJ, Paloski WH. Challenges to the central nervous system during human spaceflight missions to Mars. J Neurophysiol 2020; 123:2037-2063. [DOI: 10.1152/jn.00476.2019] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Space travel presents a number of environmental challenges to the central nervous system, including changes in gravitational acceleration that alter the terrestrial synergies between perception and action, galactic cosmic radiation that can damage sensitive neurons and structures, and multiple factors (isolation, confinement, altered atmosphere, and mission parameters, including distance from Earth) that can affect cognition and behavior. Travelers to Mars will be exposed to these environmental challenges for up to 3 years, and space-faring nations continue to direct vigorous research investments to help elucidate and mitigate the consequences of these long-duration exposures. This article reviews the findings of more than 50 years of space-related neuroscience research on humans and animals exposed to spaceflight or analogs of spaceflight environments, and projects the implications and the forward work necessary to ensure successful Mars missions. It also reviews fundamental neurophysiology responses that will help us understand and maintain human health and performance on Earth.
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Affiliation(s)
| | - Richard D. Boyle
- National Aeronautics and Space Administration, Ames Research Center, Moffett Field, California
| | | | - Gregory A. Nelson
- Division of Biomedical Engineering Sciences, School of Medicine Loma Linda University, Loma Linda, California
| | - Millard F. Reschke
- National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas
| | - Thomas J. Williams
- National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas
| | - William H. Paloski
- National Aeronautics and Space Administration, Johnson Space Center, Houston, Texas
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6
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Effects of centrifugation and whole-body vibrations on blood-brain barrier permeability in mice. NPJ Microgravity 2020; 6:1. [PMID: 31934612 PMCID: PMC6946672 DOI: 10.1038/s41526-019-0094-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 12/06/2019] [Indexed: 02/07/2023] Open
Abstract
Modifications of gravity levels induce generalized adaptation of mammalian physiology, including vascular, brain, muscle, bone and immunity functions. As a crucial interface between the vascular system and the brain, the blood–brain barrier (BBB) acts as a filter to protect neurons from pathogens and inflammation. Here we compare the effects of several protocols of hypergravity induced by centrifugation and whole-body vibrations (WBV) on BBB integrity. The immunohistochemistry revealed immunoglobulin G (IgG) extravasation from blood to hippocampal parenchyma of mice centrifuged at 2 × g during 1 or 50 days, whereas short exposures to higher hypergravity mimicking the profiles of spaceflight landing and take-off (short exposures to 5 × g) had no effects. These results suggest prolonged centrifugation (>1 days) at 2 × g induced a BBB leakage. Moreover, WBV were similarly tested. The short exposure to +2 × g vibrations (900 s/day at 90 Hz) repeated for 63 days induced IgG extravasation in hippocampal parenchyma, whereas the progressive increase of vibrations from +0.5 to +2 × g for 63 days was not able to affect the IgG crossing through the BBB. Overall, these results suggest that the BBB permeability is sensitive to prolonged external accelerations. In conclusion, we advise that the protocols of WBV and centrifugation, proposed as countermeasure to spaceflight, should be designed with progressively increasing exposure to reduce potential side effects on the BBB.
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7
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Kokhan VS, Kudrin VS, Shtemberg AS. Serotonin and Noradrenaline Metabolism in the Brain of Rats under the Combined Action of Radiation and Hypogravity in a Ground-based Experiment. NEUROCHEM J+ 2019. [DOI: 10.1134/s1819712419010100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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8
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Pulga A, Porte Y, Morel JL. Changes in C57BL6 Mouse Hippocampal Transcriptome Induced by Hypergravity Mimic Acute Corticosterone-Induced Stress. Front Mol Neurosci 2016; 9:153. [PMID: 28082866 PMCID: PMC5183579 DOI: 10.3389/fnmol.2016.00153] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 12/06/2016] [Indexed: 02/05/2023] Open
Abstract
Centrifugation is a widely used procedure to study the impact of altered gravity on Earth, as observed during spaceflights, allowing us to understand how a long-term physical constraint can condition the mammalian physiology. It is known that mice, placed in classical cages and maintained during 21 days in a centrifuge at 3G gravity level, undergo physiological adaptations due to hypergravity, and/or stress. Indeed, an increase of corticosterone levels has been previously measured in the plasma of 3G-exposed mice. Corticosterone is known to modify neuronal activity during memory processes. Although learning and memory performances cannot be assessed during the centrifugation, literature largely described a large panel of proteins (channels, second messengers, transcription factors, structural proteins) which expressions are modified during memory processing. Thus, we used the Illumina technology to compare the whole hippocampal transcriptome of three groups of C57Bl6/J mice, in order to gain insights into the effects of hypergravity on cerebral functions. Namely, a group of 21 days 3G-centrifuged mice was compared to (1) a group subjected to an acute corticosterone injection, (2) a group receiving a transdermal chronic administration of corticosterone during 21 days, and (3) aged mice because aging could be characterized by a decrease of hippocampus functions and memory impairment. Our results suggest that hypergravity stress induced by corticosterone administration and aging modulate the expression of genes in the hippocampus. However, the modulations of the transcriptome observed in these conditions are not identical. Hypergravity affects per-se the hippocampus transcriptome and probably modifies its activity. Hypergravity induced changes in hippocampal transcriptome were more similar to acute injection than chronic diffusion of corticosterone or aging.
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Affiliation(s)
- Alice Pulga
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
| | - Yves Porte
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
| | - Jean-Luc Morel
- Université de Bordeaux, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
- Centre National de la Recherche Scientifique, Institut des Maladies Neurodégénératives, UMR 5293Bordeaux, France
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9
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Risk of defeats in the central nervous system during deep space missions. Neurosci Biobehav Rev 2016; 71:621-632. [DOI: 10.1016/j.neubiorev.2016.10.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Revised: 10/06/2016] [Accepted: 10/11/2016] [Indexed: 02/04/2023]
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10
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Lawson BD, Rupert AH, McGrath BJ. The Neurovestibular Challenges of Astronauts and Balance Patients: Some Past Countermeasures and Two Alternative Approaches to Elicitation, Assessment and Mitigation. Front Syst Neurosci 2016; 10:96. [PMID: 27920669 PMCID: PMC5118654 DOI: 10.3389/fnsys.2016.00096] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 11/07/2016] [Indexed: 12/02/2022] Open
Abstract
Astronauts and vestibular patients face analogous challenges to orientation function due to adaptive exogenous (weightlessness-induced) or endogenous (pathology-induced) alterations in the processing of acceleration stimuli. Given some neurovestibular similarities between these challenges, both affected groups may benefit from shared research approaches and adaptation measurement/improvement strategies. This article reviews various past strategies and introduces two plausible ground-based approaches, the first of which is a method for eliciting and assessing vestibular adaptation-induced imbalance. Second, we review a strategy for mitigating imbalance associated with vestibular pathology and fostering readaptation. In discussing the first strategy (for imbalance assessment), we review a pilot study wherein imbalance was elicited (among healthy subjects) via an adaptive challenge that caused a temporary/reversible disruption. The surrogate vestibular deficit was caused by a brief period of movement-induced adaptation to an altered (rotating) gravitoinertial frame of reference. This elicited adaptation and caused imbalance when head movements were made after reentry into the normal (non-rotating) frame of reference. We also review a strategy for fall mitigation, viz., a prototype tactile sway feedback device for aiding balance/recovery after disruptions caused by vestibular pathology. We introduce the device and review a preliminary exploration of its effectiveness in aiding clinical balance rehabilitation (discussing the implications for healthy astronauts). Both strategies reviewed in this article represent cross-disciplinary research spin-offs: the ground-based vestibular challenge and tactile cueing display were derived from aeromedical research to benefit military aviators suffering from flight simulator-relevant aftereffects or inflight spatial disorientation, respectively. These strategies merit further evaluation using clinical and astronaut populations.
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Affiliation(s)
- Ben D Lawson
- U.S. Army Aeromedical Research Laboratory (USAARL) Fort Rucker, AL, USA
| | - Angus H Rupert
- U.S. Army Aeromedical Research Laboratory (USAARL) Fort Rucker, AL, USA
| | - Braden J McGrath
- Faculty of Education, Science, Technology and Maths, University of Canberra Canberra, ACT, Australia
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11
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Saldanha JN, Pandey S, Powell-Coffman JA. The effects of short-term hypergravity on Caenorhabditis elegans. LIFE SCIENCES IN SPACE RESEARCH 2016; 10:38-46. [PMID: 27662786 DOI: 10.1016/j.lssr.2016.06.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 05/23/2016] [Accepted: 06/23/2016] [Indexed: 02/08/2023]
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12
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Long-term effects of simulated microgravity and/or chronic exposure to low-dose gamma radiation on behavior and blood-brain barrier integrity. NPJ Microgravity 2016; 2:16019. [PMID: 28725731 PMCID: PMC5516431 DOI: 10.1038/npjmgrav.2016.19] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Revised: 04/05/2016] [Accepted: 04/22/2016] [Indexed: 12/11/2022] Open
Abstract
Astronauts on lengthy voyages will be exposed to an environment of microgravity and ionizing radiation that may have adverse effects on physical abilities, mood, and cognitive functioning. However, little is known about the long-term effects of combined microgravity and low-dose radiation. We exposed mice to gamma radiation using a cobalt-57 plate (0.01 cGy/h for a total dose of 0.04 Gy), hindlimb unloading to simulate microgravity, or a combination of both for 3 weeks. Mice then underwent a behavioral test battery after 1 week, 1 month, 4 months, and 8 months to assess sensorimotor coordination/balance (rotarod), activity levels (open field), learned helplessness/depression-like behavior (tail suspension test), risk-taking (elevated zero maze), and spatial learning/memory (water maze). Aquaporin-4 (AQP4) expression was assessed in the brain after behavioral testing to determine blood–brain barrier (BBB) integrity. Mice that received unloading spent significantly more time in the exposed portions of the elevated zero maze, were hypoactive in the open field, and spent less time struggling on the tail suspension test than mice that did not receive unloading. Mice in the combination group expressed more AQP4 immunoactivity than controls. Elevated zero maze and AQP4 data were correlated. No differences were seen on the water maze or rotarod, and no radiation-only effects were observed. These results suggest that microgravity may lead to changes in exploratory/risk-taking behaviors in the absence of other sensorimotor or cognitive deficits and that combined microgravity and a chronic, low dose of gamma radiation may lead to BBB dysfunction.
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13
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Mao XW, Nishiyama NC, Pecaut MJ, Campbell-Beachler M, Gifford P, Haynes KE, Becronis C, Gridley DS. Simulated Microgravity and Low-Dose/Low-Dose-Rate Radiation Induces Oxidative Damage in the Mouse Brain. Radiat Res 2016; 185:647-57. [DOI: 10.1667/rr14267.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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14
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Ranjan A, Behari J, Mallick BN. Cytomorphometric Changes in Hippocampal CA1 Neurons Exposed to Simulated Microgravity Using Rats as Model. Front Neurol 2014; 5:77. [PMID: 24904521 PMCID: PMC4032998 DOI: 10.3389/fneur.2014.00077] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 05/05/2014] [Indexed: 11/13/2022] Open
Abstract
Microgravity and sleep loss lead to cognitive and learning deficits. These behavioral alterations are likely to be associated with cytomorphological changes and loss of neurons. To understand the phenomenon, we exposed rats (225–275 g) to 14 days simulated microgravity (SMg) and compared its effects on CA1 hippocampal neuronal plasticity, with that of normal cage control rats. We observed that the mean area, perimeter, synaptic cleft, and length of active zone of CA1 hippocampal neurons significantly decreased while dendritic arborization and number of spines significantly increased in SMg group as compared with controls. The mean thickness of the postsynaptic density and total dendritic length remained unaltered. The changes may be a compensatory effect induced by exposure to microgravity; however, the effects may be transient or permanent, which need further study. These findings may be useful for designing effective prevention for those, including the astronauts, exposed to microgravity. Further, subject to confirmation, we propose that SMg exposure might be useful for recovery of stroke patients.
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Affiliation(s)
- Amit Ranjan
- School of Life Sciences, Jawaharlal Nehru University , New Delhi , India ; School of Environmental Sciences, Jawaharlal Nehru University , New Delhi , India
| | - Jitendra Behari
- School of Environmental Sciences, Jawaharlal Nehru University , New Delhi , India
| | - Birendra N Mallick
- School of Life Sciences, Jawaharlal Nehru University , New Delhi , India
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15
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Jamon M. The development of vestibular system and related functions in mammals: impact of gravity. Front Integr Neurosci 2014; 8:11. [PMID: 24570658 PMCID: PMC3916785 DOI: 10.3389/fnint.2014.00011] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 01/20/2014] [Indexed: 12/12/2022] Open
Abstract
This chapter reviews the knowledge about the adaptation to Earth gravity during the development of mammals. The impact of early exposure to altered gravity is evaluated at the level of the functions related to the vestibular system, including postural control, homeostatic regulation, and spatial memory. The hypothesis of critical periods in the adaptation to gravity is discussed. Demonstrating a critical period requires removing the gravity stimulus during delimited time windows, what is impossible to do on Earth surface. The surgical destruction of the vestibular apparatus, and the use of mice strains with defective graviceptors have provided useful information on the consequences of missing gravity perception, and the possible compensatory mechanisms, but transitory suppression of the stimulus can only be operated during spatial flight. The rare studies on rat pups housed on board of space shuttle significantly contributed to this problem, but the use of hypergravity environment, produced by means of chronic centrifugation, is the only available tool when repeated experiments must be carried out on Earth. Even though hypergravity is sometimes considered as a mirror situation to microgravity, the two situations cannot be confused because a gravitational force is still present. The theoretical considerations that validate the paradigm of hypergravity to evaluate critical periods are discussed. The question of adaption of graviceptor is questioned from an evolutionary point of view. It is possible that graviception is hardwired, because life on Earth has evolved under the constant pressure of gravity. The rapid acquisition of motor programming by precocial mammals in minutes after birth is consistent with this hypothesis, but the slow development of motor skills in altricial species and the plasticity of vestibular perception in adults suggest that gravity experience is required for the tuning of graviceptors. The possible reasons for this dichotomy are discussed.
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Affiliation(s)
- Marc Jamon
- Faculté de Médecine de la Timone, Institut National de la Santé et de la Recherche Médicale U 1106, Aix-Marseille University Marseille, France
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