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Mhatre SD, Iyer J, Puukila S, Paul AM, Tahimic CGT, Rubinstein L, Lowe M, Alwood JS, Sowa MB, Bhattacharya S, Globus RK, Ronca AE. Neuro-consequences of the spaceflight environment. Neurosci Biobehav Rev 2021; 132:908-935. [PMID: 34767877 DOI: 10.1016/j.neubiorev.2021.09.055] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 08/03/2021] [Accepted: 09/28/2021] [Indexed: 12/17/2022]
Abstract
As human space exploration advances to establish a permanent presence beyond the Low Earth Orbit (LEO) with NASA's Artemis mission, researchers are striving to understand and address the health challenges of living and working in the spaceflight environment. Exposure to ionizing radiation, microgravity, isolation and other spaceflight hazards pose significant risks to astronauts. Determining neurobiological and neurobehavioral responses, understanding physiological responses under Central Nervous System (CNS) control, and identifying putative mechanisms to inform countermeasure development are critically important to ensuring brain and behavioral health of crew on long duration missions. Here we provide a detailed and comprehensive review of the effects of spaceflight and of ground-based spaceflight analogs, including simulated weightlessness, social isolation, and ionizing radiation on humans and animals. Further, we discuss dietary and non-dietary countermeasures including artificial gravity and antioxidants, among others. Significant future work is needed to ensure that neural, sensorimotor, cognitive and other physiological functions are maintained during extended deep space missions to avoid potentially catastrophic health and safety outcomes.
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Affiliation(s)
- Siddhita D Mhatre
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; KBR, Houston, TX, 77002, USA; COSMIAC Research Center, University of New Mexico, Albuquerque, NM, 87131, USA
| | - Janani Iyer
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Stephanie Puukila
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA; Flinders University, Adelaide, Australia
| | - Amber M Paul
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Candice G T Tahimic
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; KBR, Houston, TX, 77002, USA; Department of Biology, University of North Florida, Jacksonville, FL, 32224, USA
| | - Linda Rubinstein
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Universities Space Research Association, Columbia, MD, 21046, USA
| | - Moniece Lowe
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Blue Marble Space Institute of Science, Seattle, WA, 98154, USA
| | - Joshua S Alwood
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Marianne B Sowa
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Sharmila Bhattacharya
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Ruth K Globus
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - April E Ronca
- Space Biosciences Division, NASA Ames Research Center, Moffett Field, CA, 94035, USA; Wake Forest Medical School, Winston-Salem, NC, 27101, USA.
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Lee J, Jang D, Jeong H, Kim KS, Yang S. Impairment of synaptic plasticity and novel object recognition in the hypergravity-exposed rats. Sci Rep 2020; 10:15813. [PMID: 32978417 PMCID: PMC7519067 DOI: 10.1038/s41598-020-72639-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Accepted: 08/24/2020] [Indexed: 01/03/2023] Open
Abstract
The gravity is necessary for living organisms to operate various biological events including hippocampus-related functions of learning and memory. Until now, it remains inconclusive how altered gravity is associated with hippocampal functions. It is mainly due to the difficulties in generating an animal model experiencing altered gravity. Here, we demonstrate the effects of hypergravity on hippocampus-related functions using an animal behavior and electrophysiology with our hypergravity animal model. The hypergravity (4G, 4 weeks) group showed impaired synaptic efficacy and long-term potentiation in CA1 neurons of the hippocampus along with the poor performance of a novel object recognition task. Our studies suggest that altered gravity affects hippocampus-related cognitive functions, presumably through structural and functional adaptation to various conditions of gravity shift.
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Affiliation(s)
- Jinho Lee
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - Doohyeong Jang
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - Hyerin Jeong
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea
| | - Kyu-Sung Kim
- Department of Otorhinolaryngology-Head and Neck Surgery, Inha University, College of Medicine, Incheon, South Korea. .,Inha Institute of Aerospace Medicine, Incheon, South Korea.
| | - Sunggu Yang
- Department of Nano-Bioengineering, Incheon National University, Incheon, South Korea.
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3
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Horii A, Mitani K, Masumura C, Uno A, Imai T, Morita Y, Takahashi K, Kitahara T, Inohara H. Hippocampal gene expression, serum cortisol level, and spatial memory in rats exposed to hypergravity. J Vestib Res 2017; 27:209-215. [DOI: 10.3233/ves-170521] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Arata Horii
- Department of Otolaryngology Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kenji Mitani
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan
| | - Chisako Masumura
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan
| | - Atsuhiko Uno
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan
| | - Takao Imai
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan
| | - Yuka Morita
- Department of Otolaryngology Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kuniyuki Takahashi
- Department of Otolaryngology Head and Neck Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tadashi Kitahara
- Department of Otolaryngology Head and Neck Surgery, Nara Medical University, Japan
| | - Hidenori Inohara
- Department of Otorhinolaryngology Head and Neck Surgery, Osaka University Graduate School of Medicine, Japan
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4
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Ishikawa C, Li H, Ogura R, Yoshimura Y, Kudo T, Shirakawa M, Shiba D, Takahashi S, Morita H, Shiga T. Effects of gravity changes on gene expression of BDNF and serotonin receptors in the mouse brain. PLoS One 2017; 12:e0177833. [PMID: 28591153 PMCID: PMC5462371 DOI: 10.1371/journal.pone.0177833] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 05/03/2017] [Indexed: 02/01/2023] Open
Abstract
Spaceflight entails various stressful environmental factors including microgravity. The effects of gravity changes have been studied extensively on skeletal, muscular, cardiovascular, immune and vestibular systems, but those on the nervous system are not well studied. The alteration of gravity in ground-based animal experiments is one of the approaches taken to address this issue. Here we investigated the effects of centrifugation-induced gravity changes on gene expression of brain-derived neurotrophic factor (BDNF) and serotonin receptors (5-HTRs) in the mouse brain. Exposure to 2g hypergravity for 14 days showed differential modulation of gene expression depending on regions of the brain. BDNF expression was decreased in the ventral hippocampus and hypothalamus, whereas increased in the cerebellum. 5-HT1BR expression was decreased in the cerebellum, whereas increased in the ventral hippocampus and caudate putamen. In contrast, hypergravity did not affect gene expression of 5-HT1AR, 5-HT2AR, 5-HT2CR, 5-HT4R and 5-HT7R. In addition to hypergravity, decelerating gravity change from 2g hypergravity to 1g normal gravity affected gene expression of BDNF, 5-HT1AR, 5-HT1BR, and 5-HT2AR in various regions of the brain. We also examined involvement of the vestibular organ in the effects of hypergravity. Surgical lesions of the inner ear's vestibular organ removed the effects induced by hypergravity on gene expression, which suggests that the effects of hypergravity are mediated through the vestibular organ. In summary, we showed that gravity changes induced differential modulation of gene expression of BDNF and 5-HTRs (5-HT1AR, 5-HT1BR and 5-HT2AR) in some brain regions. The modulation of gene expression may constitute molecular bases that underlie behavioral alteration induced by gravity changes.
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MESH Headings
- Animals
- Brain/metabolism
- Brain/physiology
- Brain Mapping
- Brain-Derived Neurotrophic Factor/biosynthesis
- Brain-Derived Neurotrophic Factor/metabolism
- Gene Expression Regulation
- Gravitation
- Hippocampus/metabolism
- Humans
- Mice
- Receptor, Serotonin, 5-HT1A/biosynthesis
- Receptor, Serotonin, 5-HT1A/metabolism
- Receptor, Serotonin, 5-HT1B/biosynthesis
- Receptor, Serotonin, 5-HT1B/metabolism
- Receptor, Serotonin, 5-HT2A/biosynthesis
- Receptor, Serotonin, 5-HT2A/metabolism
- Space Flight
- Vestibule, Labyrinth/metabolism
- Vestibule, Labyrinth/physiology
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Affiliation(s)
- Chihiro Ishikawa
- Laboratory of Neurobiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Haiyan Li
- Laboratory of Neurobiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Rin Ogura
- Laboratory of Neurobiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Yuko Yoshimura
- Laboratory of Neurobiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
| | - Takashi Kudo
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
| | - Masaki Shirakawa
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
- JEM Utilization Center, Human Spaceflight Technology Directorate, JAXA, Tsukuba, Ibaraki, Japan
| | - Dai Shiba
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
- JEM Utilization Center, Human Spaceflight Technology Directorate, JAXA, Tsukuba, Ibaraki, Japan
| | - Satoru Takahashi
- Laboratory Animal Resource Center, University of Tsukuba, Tsukuba, Ibaraki, Japan
- Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
| | - Hironobu Morita
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
- Department of Physiology, Gifu University Graduate School of Medicine, Gifu, Japan
| | - Takashi Shiga
- Laboratory of Neurobiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan
- Mouse Epigenetics Project, ISS/Kibo experiment, Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan
- Department of Neurobiology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
- * E-mail:
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Schmidt MA, Goodwin TJ, Pelligra R. Incorporation of omics analyses into artificial gravity research for space exploration countermeasure development. Metabolomics 2016; 12:36. [PMID: 26834514 PMCID: PMC4718941 DOI: 10.1007/s11306-015-0942-0] [Citation(s) in RCA: 11] [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: 09/16/2015] [Accepted: 10/30/2015] [Indexed: 12/15/2022]
Abstract
The next major steps in human spaceflight include flyby, orbital, and landing missions to the Moon, Mars, and near earth asteroids. The first crewed deep space mission is expected to launch in 2022, which affords less than 7 years to address the complex question of whether and how to apply artificial gravity to counter the effects of prolonged weightlessness. Various phenotypic changes are demonstrated during artificial gravity experiments. However, the molecular dynamics (genotype and molecular phenotypes) that underlie these morphological, physiological, and behavioral phenotypes are far more complex than previously understood. Thus, targeted molecular assessment of subjects under various G conditions can be expected to miss important patterns of molecular variance that inform the more general phenotypes typically being measured. Use of omics methods can help detect changes across broad molecular networks, as various G-loading paradigms are applied. This will be useful in detecting off-target, or unanticipated effects of the different gravity paradigms applied to humans or animals. Insights gained from these approaches may eventually be used to inform countermeasure development or refine the deployment of existing countermeasures. This convergence of the omics and artificial gravity research communities may be critical if we are to develop the proper artificial gravity solutions under the severely compressed timelines currently established. Thus, the omics community may offer a unique ability to accelerate discovery, provide new insights, and benefit deep space missions in ways that have not been previously considered.
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Affiliation(s)
- Michael A. Schmidt
- />Sovaris Aerospace, LLC, Advanced Pattern Analysis & Countermeasures Group, Research Innovation Center, Colorado State University, 3185 Rampart Road, Fort Collins, CO 80521 USA
| | - Thomas J. Goodwin
- />Disease Modeling and Tissue Analogues Laboratory, Biomedical Research and Environmental Sciences Division, NASA Lyndon B. Johnson Space Center, Houston, TX 77058 USA
| | - Ralph Pelligra
- />Chief Medical Officer, NASA Ames Research Center, Moffett Field, CA USA
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6
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The long-term consequences of the exposure to increasing gravity levels on the muscular, vestibular and cognitive functions in adult mice. Behav Brain Res 2014; 264:64-73. [DOI: 10.1016/j.bbr.2014.01.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 01/14/2014] [Accepted: 01/19/2014] [Indexed: 11/20/2022]
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7
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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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8
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Porte Y, Morel JL. Learning on Jupiter, learning on the Moon: the dark side of the G-force. Effects of gravity changes on neurovascular unit and modulation of learning and memory. Front Behav Neurosci 2012; 6:64. [PMID: 23015785 PMCID: PMC3449275 DOI: 10.3389/fnbeh.2012.00064] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 09/06/2012] [Indexed: 12/14/2022] Open
Abstract
On earth, gravity vector conditions the development of all living beings by physically imposing an axis along which to build their organism. Thus, during their whole life, they have to fight against this force not only to maintain their architectural organization but also to coordinate the communication between organs and keep their physiology in a balanced steady-state. In space, astronauts show physiological, psychological, and cognitive deregulations, ranging from bone decalcification or decrease of musculature, to depressive-like disorders, and spatial disorientation. Nonetheless, they are confronted to a great amount of physical changes in their environment such as solar radiations, loss of light-dark cycle, lack of spatial landmarks, confinement, and obviously a dramatic decrease of gravity force. It is thus very hard to selectively discriminate the strict role of gravity level alterations on physiological, and particularly cerebral, dysfunction. To this purpose, it is important to design autonomous models and apparatuses for behavioral phenotyping utilizable under modified gravity environments. Our team actually aims at working on this area of research.
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Affiliation(s)
- Yves Porte
- Université de Bordeaux Bordeaux, France ; Centre National de la Recherche Scientifique Unité Mixte de Recherche 5293, Institut des Maladies Neurodégénératives Talence, France
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9
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Santucci D, Kawano F, Ohira T, Terada M, Nakai N, Francia N, Alleva E, Aloe L, Ochiai T, Cancedda R, Goto K, Ohira Y. Evaluation of gene, protein and neurotrophin expression in the brain of mice exposed to space environment for 91 days. PLoS One 2012; 7:e40112. [PMID: 22808101 PMCID: PMC3392276 DOI: 10.1371/journal.pone.0040112] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Accepted: 05/31/2012] [Indexed: 11/22/2022] Open
Abstract
Effects of 3-month exposure to microgravity environment on the expression of genes and proteins in mouse brain were studied. Moreover, responses of neurobiological parameters, nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF), were also evaluated in the cerebellum, hippocampus, cortex, and adrenal glands. Spaceflight-related changes in gene and protein expression were observed. Biological processes of the up-regulated genes were related to the immune response, metabolic process, and/or inflammatory response. Changes of cellular components involving in microsome and vesicular fraction were also noted. Molecular function categories were related to various enzyme activities. The biological processes in the down-regulated genes were related to various metabolic and catabolic processes. Cellular components were related to cytoplasm and mitochondrion. The down-regulated molecular functions were related to catalytic and oxidoreductase activities. Up-regulation of 28 proteins was seen following spaceflight vs. those in ground control. These proteins were related to mitochondrial metabolism, synthesis and hydrolysis of ATP, calcium/calmodulin metabolism, nervous system, and transport of proteins and/or amino acids. Down-regulated proteins were related to mitochondrial metabolism. Expression of NGF in hippocampus, cortex, and adrenal gland of wild type animal tended to decrease following spaceflight. As for pleiotrophin transgenic mice, spaceflight-related reduction of NGF occured only in adrenal gland. Consistent trends between various portions of brain and adrenal gland were not observed in the responses of BDNF to spaceflight. Although exposure to real microgravity influenced the expression of a number of genes and proteins in the brain that have been shown to be involved in a wide spectrum of biological function, it is still unclear how the functional properties of brain were influenced by 3-month exposure to microgravity.
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Affiliation(s)
- Daniela Santucci
- Behavioural Neuroscience Section, Cellular Biology and Neuroscience Department, Istituto Superiore di Sanità, Rome, Italy
| | | | - Takashi Ohira
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | | | - Naoya Nakai
- Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Nadia Francia
- Behavioural Neuroscience Section, Cellular Biology and Neuroscience Department, Istituto Superiore di Sanità, Rome, Italy
| | - Enrico Alleva
- Behavioural Neuroscience Section, Cellular Biology and Neuroscience Department, Istituto Superiore di Sanità, Rome, Italy
| | - Luigi Aloe
- Institute of Neurobiology and Molecular Medicine, CNR, European Brain Research Institute, Rome, Italy
| | | | | | - Katsumasa Goto
- Graduate School of Health Sciences, Toyohashi SOZO University, Aichi, Japan
| | - Yoshinobu Ohira
- Graduate School of Medicine, Osaka University, Osaka, Japan
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
- * E-mail:
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10
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Smith PF, Darlington CL, Zheng Y. Move it or lose it--is stimulation of the vestibular system necessary for normal spatial memory? Hippocampus 2010; 20:36-43. [PMID: 19405142 DOI: 10.1002/hipo.20588] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Studies in both experimental animals and human patients have demonstrated that peripheral vestibular lesions, especially bilateral lesions, are associated with spatial memory impairment that is long-lasting and may even be permanent. Electrophysiological evidence from animals indicates that bilateral vestibular loss causes place cells and theta activity to become dysfunctional; the most recent human evidence suggests that the hippocampus may cause atrophy in patients with bilateral vestibular lesions. Taken together, these studies suggest that self-motion information provided by the vestibular system is important for the development of spatial memory by areas of the brain such as the hippocampus, and when it is lost, spatial memory is impaired. This naturally suggests the converse possibility that activation of the vestibular system may enhance memory. Surprisingly, there is some human evidence that this may be the case. This review considers the relationship between the vestibular system and memory and suggests that the evolutionary age of this primitive sensory system as well as how it detects self-motion (i.e., detection of acceleration vs. velocity) may be the reasons for its unique contribution to spatial memory.
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Affiliation(s)
- Paul F Smith
- Department of Pharmacology and Toxicology, School of Medical Sciences, University of Otago Medical School, Dunedin, New Zealand.
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11
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Sun XQ, Xu ZP, Zhang S, Cao XS, Liu TS. Simulated weightlessness aggravates hypergravity-induced impairment of learning and memory and neuronal apoptosis in rats. Behav Brain Res 2009; 199:197-202. [DOI: 10.1016/j.bbr.2008.11.035] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 11/20/2008] [Accepted: 11/25/2008] [Indexed: 10/21/2022]
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12
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Niihori M, Mogami Y, Naruse K, Baba SA. Development and swimming behavior of Medaka fry in a spaceflight aboard the Space Shuttle Columbia (STS-107). Zoolog Sci 2005; 21:923-31. [PMID: 15459450 DOI: 10.2108/zsj.21.923] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A space experiment aimed at closely observing the development and swimming activity of medaka fry under microgravity was carried out as a part of the S*T*A*R*S Program, a space shuttle mission, in STS-107 in January 2003. Four eggs laid on earth in an artificially controlled environment were put in a container with a functionally closed ecological system and launched on the Space Shuttle Columbia. Each egg was held in place by a strip of Velcro in the container to be individually monitored by close-up CCD cameras. In the control experiment, four eggs prepared using the same experimental set-up remained on the ground. There was no appreciable difference in the time course of development between space- and ground-based embryos. In the ground experiment, embryos were observed to rotate in place enclosed with the egg membrane, whereas those in the flight unit did not rotate. One of the four eggs hatched on the 8th day after being launched into space. All four eggs hatched in the ground unit. The fry hatched in space was mostly motionless, but with occasional control of its posture with respect to references in the experimental chamber. The fry hatched on ground were observed to move actively, controlling their posture with respect to the gravity vector. These findings suggest that the absence of gravity affects the initiation process of motility of embryos and hatched fry.
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Affiliation(s)
- Maki Niihori
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo, Japan.
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13
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Mitani K, Horii A, Kubo T. Impaired spatial learning after hypergravity exposure in rats. ACTA ACUST UNITED AC 2005; 22:94-100. [PMID: 15561505 DOI: 10.1016/j.cogbrainres.2004.08.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/09/2004] [Indexed: 10/26/2022]
Abstract
Most astronauts experience spatial disorientation after exposure to weightlessness, indicating that constant gravity is utilized as a stable external reference during spatial cognition. We attempted to elucidate the role of constant gravity in spatial learning using a radial arm maze test on rats housed in a hypergravity environment (HG) produced by a centrifuge device. Male Wistar rats were kept in 2G linear acceleration for 2 weeks before the spatial learning task, which lasted for 10 days. The control rats were placed close to the centrifuge device but not exposed to hypergravity. Spatial learning was evaluated by the accuracy and the re-entry rate, which were the rate of correct arm entries and the rate of entries into the arms that they had already visited, respectively. Locomotor activity was measured by number of entries per minute. The number of baits the animal took per minute was also measured. The results showed that accuracy was significantly inferior and the re-entry rate was significantly higher in the HG rats than in the controls, suggesting that animals use a constant gravity as a stable external reference in spatial learning. However, these differences disappeared at 5 days later, indicating that the HG rats learned the spatial task more rapidly than the controls. Locomotor activity was higher in the HG rats and there was no difference in number of baits per minute between the HG and control animals. In conclusion, if one sensory cue necessary for spatial cognition is disturbed by gravity change, animals can subsidize with other sensory cues such as proprioceptive and motor efference copy signals through increased locomotor activities.
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Affiliation(s)
- Kenji Mitani
- Department of Otolaryngology, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
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14
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Bouët V, Borel L, Harlay F, Gahéry Y, Lacour M. Kinematics of treadmill locomotion in rats conceived, born, and reared in a hypergravity field (2 g). Behav Brain Res 2004; 150:207-16. [PMID: 15033294 DOI: 10.1016/s0166-4328(03)00258-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2003] [Revised: 07/21/2003] [Accepted: 07/21/2003] [Indexed: 11/28/2022]
Abstract
The kinematics of treadmill locomotion in rats conceived, born, and raised in a hypergravity environment (HG: 2g) until the age of 3 months was investigated for 5 weeks after their exposition to earth's gravity. The locomotor performance of the HG rats (N=7) was compared to that of age-matched control rats (N=8) housed at 1g for the same period. Kinematic analysis of treadmill locomotion was performed up to 35 days of terrestrial life by an optoelectronic motion analyzer (ELITE system). Results showed that the HG rats exhibited a faster locomotor rhythm (increased number of steps/s), walked closer to the ground, and had a more dorsiflexed foot position. Also, HG rats had shorter steps. The data also highlight a fast adaptation to normal gravity since all the locomotor parameters returned to normal values within 3 weeks. The locomotor modifications may be seen as the persistence of a hypergravity-induced posturo-locomotor adaptation in the centrifuge and/or to more functional changes of sensorimotor systems. Because locomotor performance of HG rats is not severely affected, it is concluded that early development of locomotion processes is highly resistant to gravito-inertial changes.
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Affiliation(s)
- V Bouët
- UMR 6149, Laboratoire de Neurobiologie Intégrative et Adaptative, 52 Faculté de St-Jérôme, CNRS/Université de Provence, Case 361, 13397 Marseille Cedex 20, France.
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15
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Del Signore A, Mandillo S, Rizzo A, Di Mauro E, Mele A, Negri R, Oliverio A, Paggi P. Hippocampal gene expression is modulated by hypergravity. Eur J Neurosci 2004; 19:667-77. [PMID: 14984417 DOI: 10.1111/j.0953-816x.2004.03171.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We used the cDNA microarray technique to monitor simultaneously possible changes induced by hypergravity in the expression level of thousands of hippocampal genes. We tested the mRNA level of about 5000 genes in the hippocampus of mice subjected to 1.09 g (1g) or to 1.85 g (2g) for five repeated 1-h daily rotations in a centrifuge (g = 9.81 m/s2). Data were compared with those obtained for mice kept stationary (C). The ratios 1g/C and 2g/C identified genes affected by rotation and rotation + hypergravity, respectively, whereas 2g/1g ratio identified those affected by hypergravity. We found that about 200 genes were affected by rotation and/or rotation + hypergravity. Almost all the genes affected by rotation + hypergravity were up-regulated, only five being down-regulated. The modulated genes code for proteins involved in a wide range of cellular functions (DNA/RNA metabolism, protein processing, intermediate metabolism, cytoskeleton and motility, cell cycle and apoptosis, signal transduction, neuronal structure/function), suggesting that rotation + hypergravity may affect several aspects of the hippocampal function in order to compensate for environmental changes. Six genes directly or indirectly involved in synaptic transmission and plasticity (proSAAS, neuroblastoma ras oncogene, ESTs moderately similar to thymosin beta-10, syndet, inhibin beta E and Ngfi-A binding protein 2) were found to be significantly modulated by hypergravity and unaffected or only slightly affected by rotation. The modulation by hypergravity of these genes suggests that this stimulus might induce plastic remodelling of the hippocampal circuits, possibly both at structural and functional level.
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Affiliation(s)
- A Del Signore
- Dipartimento di Biologia Cellulare e dello Sviluppo, Fondazione 'Istituto Pasteur-Fondazione Cenci Bolognetti', Università'La Sapienza', P.le Aldo Moro, 5, 00185 Rome, Italy
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16
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Francia N, Santucci D, Aloe L, Alleva E. Neurobehavioral coping to altered gravity: endogenous responses of neurotrophins. PROGRESS IN BRAIN RESEARCH 2004; 146:185-94. [PMID: 14699965 DOI: 10.1016/s0079-6123(03)46013-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
An altered gravitational environment represents a unique challenge for biological systems that have evolved against gravitational background. Ground-based and space research indicates that the developing nervous system is potentially affected by exposure to hyper/microgravity. With the construction of the orbiting International Space Station long-term research on the nervous system will be possible. With this perspective, we started ground-based studies to characterize mouse behavioral responses to rotation-induced 2 g hypergravity, using a custom-made centrifuge device. Brain levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) as well as NGF and BDNF expression and mast cell distribution in heart and lung, were evaluated and correlated with the changes in mouse behavior upon hypergravity exposure. Hypergravity strongly affected the spontaneous activity of the animals, selectively modifying mouse behavioral repertoire. Such changes were mainly related to variations in brain levels of NGF, while BDNF was slightly affected, thus confirming a role for these neurotrophins in neuronal plasticity underlying experience-induced neurobehavioral changes. Moreover, gender differences were observed in both behavioral and neurobiological responses to hypergravity. These results indicate that changes in the gravitational environment might represent a useful tool to investigate the neurobiological and behavioral responses to stressors and may provide insights into the mechanisms underlying development and plasticity of nervous system in brain, heart, and lung.
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Affiliation(s)
- Nadia Francia
- Behavioral Pathophysiology Section, Istituto Superiore di Sanità (ISS), Rome, Italy
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