Hyperoxygenation Ameliorates Stress-induced Neuronal and Behavioral Deficits

Area of Science:

• Neuroscience
• Hyperbaric Medicine
• Stress Research

Background:

• Chronic stress leads to maladaptive genomic changes and depressive behaviors.
• Hyperoxygenation therapy shows promise in animal models for neuronal injury and cognitive deficits.

Purpose of the Study:

• To investigate optimal conditions for hyperoxygenation therapy in reversing stress-induced maladaptive changes.
• To evaluate the efficacy of hyperoxygenation in ameliorating stress-induced neuronal and behavioral deficits in mice.

Main Methods:

• Mice exposed to chronic restraint stress (CRST) were treated with 100% oxygen (HO2) at 2.0 ATA for 1 hour daily for 14 days.
• Various treatment durations (3, 5, 7 days), pressures (1.5 ATA), and oxygen concentrations (hyperbaric air) were tested for comparison.
• Neurogenesis, mitochondrial copy number, and neuronal structure (synaptophysin, MAP-2) in the hippocampus were assessed.

Main Results:

• 14 days of HO2 at 2.0 ATA demonstrated an antidepressive effect comparable to imipramine.
• Shorter durations, lower pressure, or hyperbaric air were ineffective or less effective, indicating the necessity of sufficient hyperoxygenation.
• HO2 treatment restored hippocampal mitochondrial copy number, synaptic density, dendritic processes, and neurogenesis.

Conclusions:

• Repeated, sufficient hyperoxygenation (100% O2 at 2.0 ATA for 14 days) is required to reverse stress-induced maladaptive changes.
• This hyperoxygenation regimen effectively ameliorates stress-induced neuronal and behavioral deficits.
• The findings suggest a potential therapeutic strategy for stress-related neurological disorders.