Changes in C57BL6 Mouse Hippocampal Transcriptome Induced by Hypergravity Mimic Acute Corticosterone-Induced Stress

Area of Science:

• Neuroscience
• Space Biology
• Genomics

Background:

• Centrifugation simulates altered gravity, crucial for understanding spaceflight's physiological effects on mammals.
• Hypergravity exposure (3G) in mice increases corticosterone levels, a hormone influencing neuronal activity and memory.
• Aging also impairs hippocampus function and memory, providing a comparative model for brain changes.

Purpose of the Study:

• To investigate the effects of sustained hypergravity on the hippocampal transcriptome in mice.
• To compare hypergravity-induced gene expression changes with those induced by acute/chronic corticosterone administration and aging.

Main Methods:

• Utilized Illumina technology for whole hippocampal transcriptome sequencing in C57Bl6/J mice.
• Compared gene expression profiles of three groups: 21-day 3G-centrifuged mice, mice with acute corticosterone injection, mice with chronic transdermal corticosterone administration, and aged mice.

Main Results:

• Hypergravity stress, corticosterone administration, and aging all modulate hippocampal gene expression.
• The specific transcriptomic changes induced by hypergravity differ from those caused by chronic corticosterone or aging.
• Hypergravity-induced hippocampal transcriptome alterations more closely resemble those from acute corticosterone injection.

Conclusions:

• Sustained hypergravity significantly affects the hippocampus transcriptome, suggesting a direct impact on cerebral functions.
• The observed transcriptomic changes indicate that hypergravity exposure modifies hippocampal activity independently of chronic stress or aging effects.
• Findings highlight the unique impact of hypergravity on brain gene expression, relevant for understanding spaceflight's neurological consequences.