lundi 4 mai 2015

The brains of astronauts threatened by cosmic rays












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May 4, 2015

SPACE: The duration of a mission to Mars would be sufficient for serious symptoms ...

Astronauts of long duration mission are very exposed for serious radiation

Exposure to radiation, such as radiant in the cosmos, which bombard astronauts during long space trips to Mars, for example, damages the central nervous system and causes permanent cognitive impairment, according to experiments on mice.

"This is not good news for astronauts who make a journey of two to three years return to Mars," said Charles Limoli, the University of California at Irvine, lead author of the research published Friday the journal Advances Science.

"Altering cognitive abilities"

"The decline in work capacity, memory deficits and loss of consciousness and difficulty concentrating during flights in space could affect the core activities of the mission," he explains, adding that "these cosmic radiation could impair the cognitive abilities of astronauts throughout their lives. "

Artist's rendering of the Multi-Purpose Crew Vehicle on a deep space mission

For this research the scientists subjected mice to radiation of high energy particles at Brookhaven National Laboratory (New York). They found that these radiations caused an inflammation in the brains of rodents that disrupted the transmission of nerve signals. Scans revealed how the brain of the communications network was affected by reductions in neuron structure.

Symptoms after a few months

Impairments of synapses that connect neurons, combined with other structural changes interfered with the ability of nerve cells to efficiently transmit electrochemical signals, the researchers explain.

These phenomena corresponded to decreased performance of different learning ability assessment tests and memorize. Although such cognitive deficits in astronauts will not manifest for several months, the duration of a mission to Mars would be sufficient for such symptoms appear, according to Dr. Limoli.

Protected by the Earth's magnetosphere

But, he explains, astronauts on the International Space Station (ISS), which stays of six months, are not exposed to as great intensity because they are protected by the Earth's magnetosphere. The orbital outpost moves between 350 and 400 km altitude. The particles forming cosmic rays are remnants of ancient supernovas, giant explosions marking the death of a star.

Earth's magnetosphere

The work of Dr. Limoli are part of the research program of NASA on the effects of prolonged space flight on humans in preparation for future manned missions to Mars. One solution would be that the spacecraft include enhanced protection against cosmic radiation areas including rest areas, the researchers said.

Related link:

Advances Science article http://advances.sciencemag.org/content/1/4/e1400256

Images, Text, Credits: ATS/NASA/Wikimedia/Orbiter.ch Aerospace.

Greetings, Orbiter.ch

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