Science in Brief:
Cause of astronauts' eye problems found
Scott Kelly, now retired, has spoken of eye issues during his year in space. Image: NASA.
Understanding the cause of vision issues could help protect crew members in the future, according to new research.
In studying the problem, scientists compared high-resolution brain scans before and after the flights of seven long-duration International Space Station astronauts and nine short-duration astronauts. The eye problems were more pronounced for long-duration astronauts.
Issues have included blurry vision along with structural changes, specifically, “flattening at the back of their eyeballs and inflammation of the head of their optic nerves,” according to the Radiological Society of North America. Nearly two-thirds of astronauts involved in long-duration missions aboard the space station experience the syndrome, known as visual impairment intracranial pressure. For more on the study, see the society's website.
MARIJUANA’S IMPACT STUDIED: Just as excitement is building over the legalization of marijuana, a team of scientists has found disturbing evidence that weed affects blood flow in the brain. The areas of the brain impacted -- such as the hippocampus -- are known to be involved in Alzheimer’s disease.
The hippocampus is the region of the brain “thought to be the center of emotion, memory and the autonomic nervous system,” according to Oxford Dictionaries online.
“Low blood flow in the hippocampus in marijuana users reliably distinguished marijuana users from controls (those who don’t use marijuana),” according to a news release from the Journal of Alzheimer’s Disease. “The right hippocampus during a concentration task was the single most predictive region in distinguishing marijuana users from their normal counterparts. Marijuana use is thought to interfere with memory formation by inhibiting activity in this part of the brain.”
See more on the study on the journal's website.
Related:
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Year in space leaves astronaut sore, tired
Marijuana affects how users process emotions
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