A study of fish in space reveals the effects of zero gravity in the bone structures of astronauts. Researchers investigate the live imaging of the medaka fish larvae, also known as Japanese rice fish in the International Space Station (ISS). It revealed that microgravity has detrimental effects to bones.
Spaceflights have various negative effects to the human body. Long-term weightlessness in areas with microgravity might lead to muscle atrophy and deterioration of the skeleton. Other negative effects include balance disorders and eyesight disorders. It can also weaken the immune system and make cardiovascular system functions, like production of red blood cells, slower than normal.
In a study published in Scientific Reports, a team of researchers from Japan studied a total of 273 images from a 5x and 20x objective lens. The images showed the overall picture of the medaka chamber using remote real-time live imaging. They studied the fluorescent signals from osteoblasts and osteoclasts of the medaka fish. Osteoblasts are cells that make bone mass while osteoclasts are cells which breaks it down.
The team used a modified fluorescence microscope to observe the samples of fish in space as well as a control group on Earth. Over an eight-day observation period, they found out that the intensity of fluorescent signals of osteoblasts and osteoclasts was significantly higher (up to eight times more) in the fishes in the ISS.
The study concludes that microgravity results to "dynamic alteration of gene expressions in osteoblasts and osteoclast," lead researcher, Akiro Kudo told Photonics Media. "These experiments based on real-time imaging of medaka from Earth and transcriptome analysis could be the prelude to the establishment of a new scientific area of research in gravitational biology," Kudo added.
After the study of bone cells of fish in space, the group plans to find out the effects of microgravity on glucocorticoid receptors (GR) on cells. GR is responsible for regulating the genes which controls the metabolism and immune response. The team plans to use the same live-cell imaging technique.