Cognitive Function, Sleep, and Neuroinflammatory Markers in Mice Exposed to Very Long-Term Intermittent Hypoxia

Area of Science:

• Neuroscience
• Sleep Medicine
• Gerontology

Background:

• Chronic intermittent hypoxia (IH) is characteristic of obstructive sleep apnea (OSA).
• The long-term impact of IH on neurocognitive and behavioral functions remains understudied.
• Understanding IH duration's effects is crucial for managing OSA-related complications.

Purpose of the Study:

• To investigate the long-term effects of IH exposure on cognitive function, anxiety, and neuroinflammation.
• To assess how prolonged IH, mimicking untreated OSA, influences biological aging markers.
• To determine the correlation between IH duration and its detrimental health outcomes.

Main Methods:

• Male C57Bl/6J mice were exposed to IH for 96 weeks.
• Sleep activity was monitored using a piezoelectric system.
• Cognitive function (Novel Object Recognition) and anxiety (Elevated Plus Maze) were assessed.
• Brain inflammation markers were quantified via assays.

Main Results:

• Prolonged IH exposure (96 weeks) led to decreased sleep percentages during the dark phase.
• Mice exposed to long-term IH exhibited impaired novel object recognition performance compared to controls.
• IH exposure increased anxiety-like behavior and elevated inflammatory marker expression in the brain.
• Both aging and IH induced similar changes in sleep, cognition, and neuroinflammation, with IH exacerbating aging effects.

Conclusions:

• Long-term IH exposure significantly impairs cognitive function and increases anxiety.
• IH exacerbates age-related declines in cognition and promotes neuroinflammation.
• Obstructive sleep apnea may accelerate biological aging processes, highlighting the need for timely intervention.