1.Identification of Vestibular Organ Originated Information on Spatial Memory in Mice
Gyu Cheol HAN ; Minbum KIM ; Mi Joo KIM
Journal of the Korean Balance Society 2018;17(4):134-141
OBJECTIVES: We aimed to study the role of vestibular input on spatial memory performance in mice that had undergone bilateral surgical labyrinthectomy, semicircular canal (SCC) occlusion and 4G hypergravity exposure. METHODS: Twelve to 16 weeks old ICR mice (n=30) were used for the experiment. The experimental group divided into 3 groups. One group had undergone bilateral chemical labyrinthectomy, and the other group had performed SCC occlusion surgery, and the last group was exposed to 4G hypergravity for 2 weeks. The movement of mice was recorded using camera in Y maze which had 3 radial arms (35 cm long, 7 cm high, 10 cm wide). We counted the number of visiting arms and analyzed the information of arm selection using program we developed before and after procedure. RESULTS: The bilateral labyrinthectomy group which semicircular canal and otolithic function was impaired showed low behavioral performance and spacial memory. The semicircular canal occlusion with CO₂ laser group which only semicircular canal function was impaired showed no difference in performance activity and spatial memory. However the hypergravity exposure group in which only otolithic function impaired showed spatial memory function was affected but the behavioral performance was spared. The impairment of spatial memory recovered after a few days after exposure in hypergravity group. CONCLUSIONS: This spatial memory function was affected by bilateral vestibular loss. Space-related information processing seems to be determined by otolithic organ information rather than semicircular canals. Due to otolithic function impairment, spatial learning was impaired after exposure to gravity changes in animals and this impaired performance was compensated after normal gravity exposure.
Animals
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Arm
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Automatic Data Processing
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Gravitation
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Hypergravity
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Memory
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Mice
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Mice, Inbred ICR
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Otolithic Membrane
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Semicircular Canals
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Spatial Learning
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Spatial Memory
2.Mircocarriers' motion in rotating wall vessels.
Xiao MA ; Chun YANG ; Fengyuan ZHUANG
Journal of Biomedical Engineering 2010;27(6):1433-1438
Rotating wall vessels (RWVS), an ingenious apparatus for three-dimensional suspension culture, is widely used to build a simulated microgravity-effect on cell. Independent researchers have proposed hypotheses to illustrate why RWVS can simulate certain aspects of microgravity. Many of the hypotheses stated that the culture condition in RWVS is determined by the cellular mechanical environment which is a result of low fluid shear and microcarrier's motion. The microcarrier's motions consist of primary and secondary motions. In the light of the analysis of forces loaded by the microcarriers, some conclusions are drawn from the data on microcarriers' primary and secondary motions about which many simulations and observations have already been conducted.
Cell Culture Techniques
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instrumentation
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methods
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Gravitation
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Models, Theoretical
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Motion
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Rotation
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Stress, Mechanical
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Weightlessness Simulation
3.(Possible) molecular mechanism of cells in gravisensing.
Journal of Biomedical Engineering 2008;25(1):227-230
Although it is clear that changes of gravity can alter dramatically the functions and structures of cells, little is known about how living cells sense these signals and convert them into a biochemical response. Recent studies estimated that the changes of gravity might influence the single cell directly and indirectly. So far, the molecular mechanism of gravisensing remains unknown, however, according to a great deal of researches focusing on this point, several pathways could be considered: (1) Pre-stress perception pathway; (2) Cytoskeleton-perception pathway; (3) Stress-sensitive ion channel pathway; (4) Indirect effects of gravitational change.
Cell Physiological Phenomena
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Cytoskeleton
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physiology
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Gravitation
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Gravity Sensing
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physiology
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Signal Transduction
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Space Flight
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Weightlessness
4.Frequency of the "Gravity Transition Effect" during Aerial Combat Mission of F-16 Aircraft, ROKAF.
Korean Journal of Aerospace and Environmental Medicine 2004;14(3):100-104
BACKGROUND: Current studies have focused mainly on the push-pull effect (PPE), the reduction of +Gz tolerance when hypergravity (>+1 Gz) preceded by hypogravity (<+1 Gz). However, the reduced G tolerance could be induced by any G-transition. The frequency and extent of maneuvers to cause G-transition effect (GTEM) have not been studied previously in fighter aircraft. METHODS: 26 HUD (head-up display) videotapes from F-16 aerial combat training missions were reviewed for the presence of GTEM. The frequency and magnitude of the +Gz profiles were analyzed. RESULTS: GTEMs were found in 34 (29.6%) of 115 engagements reviewed. PPEMs (maneuvers found to cause push-pull effect) and rPPEMs (maneuvers found to cause reversed PPE) were found in 7.8%, 11.3% respectively. Combined maneuver that rPPEM followed by PPEM consecutively was found in 10.4% of engagements. There was no difference the frequency of GTEMs between BFM and ACM engagements (28.8% vs. 30.9%). CONCLUSION: GTEMs including PPEMs and rPPEMs are present in aerial combat training missions of F-16 aircraft and represent a significant source for accidents. These findings support the necessity of continued research into the physiologic response to GTE.
Aircraft*
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Humans
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Hypergravity
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Hypogravity
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Missions and Missionaries*
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Videotape Recording
5.c-fos mRNA Expression in the Vestibular System following Hypergravity Stimulation in Rats.
Guang Shi JIN ; Jae Hyo LEE ; Jae Hee LEE ; Moon Young LEE ; Min Sun KIM ; Yuan Zhe JIN ; Jeong Hoon SONG ; Byung Rim PARK
The Korean Journal of Physiology and Pharmacology 2007;11(1):1-7
Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular related tissues following an exposure to hypergravity stimulus was determined in rats. The animals were subjected to a force of 2 g (twice earth's gravity) for 1, 3, or 12 h, and were examined poststimulus at 0, 2, 6, 12, and 24 h. RT-PCR (reverse transcription polymerase chain reaction) and real-time quantitative RT-PCR were adopted to analyze temporal changes in the expression of c-fos mRNA. The hypergravity stimulus increased the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, cerebellum, and cortex. The peak expression occurred at 0 h poststimulation in animals stimulated with hypergravity for 1 h, and at 6 h poststimulus in those stimulated for 3 h. In contrast, those stimulated for 12 h exhibited dual peaks at 0 and 12 h poststimulus. Bilateral labyrinthectomy markedly attenuated the degree of c-fos mRNA expression. Glutamate receptor antagonist also dramatically attenuated the degree of c-fos mRNA expression. These results indicate that expression of c-fos mRNA in response to hypergravity occurs in the vestibular related tissues of the central nervous system, in which peripheral vestibular receptors and glutamate receptors play an important role. The temporal pattern of c-fos mRNA expression depended on the duration of the hypergravity stimulus.
Animals
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Central Nervous System
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Cerebellum
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Ganglion Cysts
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Gravitation
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Hippocampus
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Hypergravity*
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Plastics
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Rats*
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Receptors, Glutamate
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RNA, Messenger*
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Space Motion Sickness
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Vestibular Nuclei
6.Unusual manifestation of right upper lober collapse due to bronchogenic carcinoma
Jeong Ho KWAK ; Seong Ku WOO ; Yup YOON ; Soon Yong KIM ; Chi Yul AHN
Journal of the Korean Radiological Society 1984;20(2):262-265
In the unusual manifestation of right upper lobe collapse confusing with mediastinal or parenchymal mass, both alteration of the pulmonary vessels and shifting pattern of the collapsed lobe to the periphery on supine positionare the key to the diagnosis of it rather than mediastinal or parenchymal mass. The mechanisms of these unusual manifestation s are obscure, however lobar torsion and gravity factor are considered to be a main process. Authors have experienced 2 cases of unusual manifestations of right upper lobe collapse due to bronchogenic carcinomaduring resent 2 years in Kyung Hee University hospital, and prsent radiologic findings.
Carcinoma, Bronchogenic
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Diagnosis
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Gravitation
7.Role of the Peripheral Vestibular System on Neuroplasticity Induced by Hypergravity Stimulation .
Jae Hyo LEE ; Gyoung Wan LEE ; Han Su PARK ; Jae Hee LEE ; Dong Ok CHOI ; Myoung Ae CHOI ; Byung Rim PARK
Journal of the Korean Balance Society 2006;5(2):213-223
BACKGROUND AND OBJECTIVES: Altered environmental gravity, including both hypo- and hypergravity, may result in space adaptation syndrome. To explore the characteristics of this adaptive plasticity, the expression of immediate early gene c-fos mRNA in the vestibular system following an exposure to hypergravity stimulus was determined in rats. MATERIALS AND METHOD: The animals were subjected to 2 G force (two-fold earth's gravity) stimulus for 3 hours, and were examined at post-stimulus hours 0, 2, 6, 12, and 24. Real time reverse transcription-polymerase chain reaction (RT-PCR) was adopted to analyze temporal changes in the expression of c-fos mRNA. RESULTS: The hypergravity stimulation produced the expression of c-fos mRNA in the vestibular ganglion, medial vestibular nucleus, inferior vestibular nucleus, hippocampus, vestibulocerebellum, and vestibular cortex. The peak expression occurred at hour 6 in the animals hypergravity-stimulated for 3 hours. Bilateral labyrinthectomy significantly attenuated the degree of up-regulation in c-fos mRNA expression. MK-801, an NMDA receptor antagonist, also significantly attenuated the degree of up-regulation in c-fos mRNA expression. CONCLUSION: These results indicate that the adaptive neuroplasticity in response to an altered gravity occurs in the vestibular-related organs in the central nervous system, in which peripheral vestibular receptors and NMDA receptors play an important role.
Animals
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Central Nervous System
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Dizocilpine Maleate
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Ganglion Cysts
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Genes, fos
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Gravitation
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Hippocampus
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Hypergravity*
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N-Methylaspartate
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Neuronal Plasticity*
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Plastics
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Rats
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Receptors, N-Methyl-D-Aspartate
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RNA, Messenger
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Space Motion Sickness
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Up-Regulation
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Vestibular Nuclei
8.Debates on Colorectal Endoscopic Submucosal Dissection - Traction for Effective Dissection: Gravity Is Enough.
Clinical Endoscopy 2013;46(5):467-471
Colorectal endoscopic submucosal dissection (ESD) still remains a technically difficult procedure. The maintenance of tissue tension and good submucosal exposure during dissection is one of the most important factors for an effective and safe dissection. Although various traction methods have been developed, traction by gravity is one of the most useful method for colorectal ESD. Traction using adjunctive devices can thus be reserved for extremely difficult cases or for endoscopists in their learning periods for colorectal ESD.
Colorectal Neoplasms
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Gravitation
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Learning
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Traction
9.Systems specificity in responsiveness to intermittent artificial gravity during simulated microgravity in rats.
Acta Physiologica Sinica 2016;68(4):391-402
It has been shown that the minimum gravity exposure requirements vary greatly among different physiological systems. A preliminary comparison between two extremes, vessels vs. bones, shows that not only the mechanostat at the tissue level differs greatly, but also the bone loss during weightlessness may also involve calcium deposition-resorption changes. It seems that the surprising efficacy of intermittent artificial gravity (IAG) is due to the vascular tissues possessing a strong resilience or "memory" function toward restoring their original pre-stress and tensegrity state at the 1 G environment. It appears that the bone tissue is related to a more complex tensegrity paradigm involving both osteoblasts and osteoclasts, and a longer half time for calcium deposition-absorption. Cell-level models (CellML) for calcium dynamics is currently available. We hope that the Physiome Project can use this modeling framework to help interpret the resistance of bones to IAG and to evaluate whether the "intermittent" or "continuous" AG scheme should be adopted eventually for future exploration-class spaceflight.
Animals
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Bone and Bones
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Calcium
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Gravity, Altered
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Osteoblasts
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Osteoclasts
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Rats
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Weightlessness
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Weightlessness Simulation
10.Shortage in residents of internal medicine and current status of Korean medical system.
Journal of the Korean Medical Association 2015;58(5):368-371
The shortage of internal medicine residents depict the contradictions and perversions in Korean medical system. Internal medicine is the foundation of medicine and the fact it serves as the most essential medical services for the people adds severe gravity to the issue. The fundamental problem derives from the contradictions in health insurance system. In fact, the poor medical fee and the failure of medical delivery system are the core drawbacks to the current crisis. Unless above matters are addressed to draw a constructive resolution, it is an undeniable fact that this may become a serious threat to the national health system and people's wellbeing.
Fees, Medical
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Gravitation
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Insurance, Health
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Internal Medicine*