Abstract
During orbital or interplanetary space flights, astronauts are exposed to cosmic radiations
and microgravity. However, most earth-based studies on the potential health risks of space
conditions have investigated the effects of these two conditions separately. This study
aimed at assessing the combined effect of radiation exposure and microgravity on neuronal
morphology and survival in vitro. In particular, we investigated the effects of simulated
microgravity after acute (X-rays) or during chronic (Californium-252) exposure to ionizing
radiation using mouse mature neuron cultures. Acute exposure to low (0.1 Gy) doses of Xrays
caused a delay in neurite outgrowth and a reduction in soma size, while only the high
dose impaired neuronal survival. Of interest, the strongest effect on neuronal morphology
and survival was evident in cells exposed to microgravity and in particular in cells exposed
to both microgravity and radiation. Removal of neurons from simulated microgravity for a
period of 24 h was not sufficient to recover neurite length, whereas the soma size showed a
clear re-adaptation to normal ground conditions. Genome-wide gene expression analysis
confirmed a modulation of genes involved in neurite extension, cell survival and synaptic
communication, suggesting that these changes might be responsible for the observed morphological
effects. In general, the observed synergistic changes in neuronal network integrity
and cell survival induced by simulated space conditions might help to better evaluate
the astronaut's health risks and underline the importance of investigating the central nervous
system and long-term cognition during and after a space flight.
Details
Original language | English |
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Number of pages | 19 |
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Journal | PLOS ONE |
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Volume | 11 |
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Issue number | 5 |
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DOIs | |
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Publication status | Published - 20 May 2016 |
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