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The Effect of Microgravity on Neuronal Cytoskeletal and Intracellular Trafficking (80NSSC19K0715)
Research Area:
Cell and molecular biology

Crew members onboard the International Space Station (ISS) exhibit a range of microgravity induced physiological dysfunctions during extended missions (>1 month). Some of the most common effects of long-term microgravity exposure include immune system dysregulation, skeletal muscle atrophy, cardiovascular decline, bone loss, cognitive impairments, and decreased motor control. Unfortunately, the underlying etiology of microgravity induced dysfunction remains unclear. Decades of NASA research on ISS and shuttle missions have demonstrated that mammalian cell cultures exhibit altered morphology, proliferation, motility, differentiation, and often increased oxidative stress when exposed to the microgravity environment. Thus, physiological dysfunction at the tissue and systemic level is likely a result of altered cellular function, subcellular structural alterations, and intracellular communications. It has been well documented that the lack of gravity on-orbit has resulted in a cytoskeletal structural reorganization within a host of adherent mammalian cell cultures. Altered microtubule organization has enormous significance in the context of neurite outgrowth and neuronal intracellular communications. Intracellular effects may include the inability to clear aging and toxic proteins, a loss of trophic factor signaling, and compromised cellular energetics, resulting in axonopathies, synaptic loss, and eventual neuron death. Intracellular trafficking of vesicles is a fundamental subcellular process that can significantly alter cellular, tissue, and systemic processes if impaired in microgravity. Previous studies on Earth have demonstrated that disrupted intracellular communication contributes to abnormal physiological processes and that intracellular processes are sensitive to cytoskeletal organization. Thus, it is likely that microtubule reorganization in microgravity impairs neurite outgrowth, intra- and intercellular communications. However, the extent to which microgravity affects neuron microtubule structure dynamics remains unknown. We hypothesize that neuron microtubule organization is altered in microgravity which leads to inhibited neurite outgrowth and reduced intracellular vesicle trafficking which ultimately contributes to the cognitive impairments, motor control decline, and reduced neuroplasticity observed in microgravity.

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Additional Information
Managing NASA Center
Ames Research Center (ARC)
Responsible NASA Representative
Ames Research Center LSDA Level 3
Project Manager: Helen Stewart
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
2016-17 Space Biology (ROSBio) NNH16ZTT001N-FG. App G: Flight and Ground Space Biology Research