Retinal changes in rats flown on Cosmos 936: A cosmic ray experiment

Area of Science:

• Space biology
• Ophthalmology
• Cell biology

Background:

• Spaceflight poses unique environmental challenges to biological systems.
• Previous studies have indicated potential cellular alterations following space missions.

Purpose of the Study:

• To investigate the effects of simulated gravity and hypogravity during spaceflight on rat retinal cells.
• To compare flight-induced changes with ground controls and identify contributing factors to retinal cell damage.

Main Methods:

• Ten rats were used: five experienced simulated gravity via centrifugation during flight, and five experienced hypogravity.
• Animals orbited the Earth, and their retinal tissues were analyzed post-flight.
• Morphological examination of retinal cells, focusing on the outer nuclear layer.

Main Results:

• No significant differences were observed between centrifuged (simulated gravity) and stationary (hypogravity) flight groups.
• Both flight groups showed distinct morphological alterations compared to ground controls.
• Affected retinal cells exhibited swelling, cytoplasmic clearing, and membrane disruption, consistent with previous findings.

Conclusions:

• Weightlessness and simulated gravity alone do not appear to be the primary cause of the observed retinal cell damage.
• Environmental conditions during spaceflight, excluding cosmic radiation, are implicated in the observed morphological changes.
• Further research is needed to identify the specific environmental factors responsible for retinal cell alterations in space.