Female mice are protected from space radiation-induced maladaptive responses

Area of Science:

• Neuroscience
• Space Biology
• Radiation Biology

Background:

• Deep space missions face challenges from galactic cosmic radiation (GCR).
• GCR exposure poses risks to astronaut health, particularly cognitive function.
• Understanding GCR's long-term effects is crucial for human interplanetary exploration.

Purpose of the Study:

• To investigate the sex-specific long-term behavioral and cellular effects of simulated GCR exposure.
• To identify potential molecular mechanisms underlying GCR-induced cognitive deficits.
• To inform strategies for mitigating risks associated with GCR for future space missions.

Main Methods:

• Exposure of male and female mice to simulated GCR.
• Assessment of long-term cognitive and behavioral phenotypes.
• Analysis of cellular and molecular changes in the hippocampus, including microglia activation and synaptic markers.

Main Results:

• Simulated GCR induced long-term cognitive and behavioral deficits exclusively in male mice.
• Male mice exhibited reduced social interaction, increased anxiety, and impaired recognition memory.
• GCR exposure in males correlated with hippocampal microglia activation, synaptic loss, and reduced AMPA receptor expression, with no observed changes in females.

Conclusions:

• GCR exposure induces sex-dependent cognitive and behavioral alterations.
• Microglia activation and synaptic alterations in the hippocampus are key mechanisms for GCR-induced cognitive deficits in males.
• Findings highlight potential targets for interventions to protect astronauts from GCR effects during long-duration spaceflight.