Evaluation of 5-hydroxytryptamine (5-HT) on Cognitive Function in Rats with Gut-Brain Axis Dysfunction Following...

Area of Science:

• Neuroscience
• Gastroenterology
• Microbiology

Background:

• Acceleration stress, such as 10 Gz, can induce gut-brain axis dysfunction.
• This dysfunction is linked to cognitive impairments and neuroinflammation.
• The role of 5-hydroxytryptamine (5-HT) in modulating these effects is not fully understood.

Purpose of the Study:

• To investigate how 5-HT modulates acceleration-induced gut-brain axis dysfunction and cognitive impacts in rats.
• To explore the underlying microbiota-immune interactions and hippocampal neuroinflammation.
• To assess the therapeutic potential of 5-HT supplementation.

Main Methods:

• Rats were exposed to 10 Gz acceleration and supplemented with either 5-HT or a placebo.
• Cognitive function was assessed using the Morris water maze and open-field test.
• Serum cytokine levels, hippocampal microglial activation, and fecal microbiota composition were analyzed.

Main Results:

• 10 Gz exposure significantly impaired cognitive function and altered gut microbiota composition (increased Firmicutes/Bacteroidetes ratio).
• 5-HT supplementation reversed cognitive deficits, enhanced beneficial Lactobacillus abundance, and attenuated serum TNF-α and IL-1β levels.
• Acceleration stress induced hippocampal CA1 microglial activation, which was significantly reduced by 5-HT supplementation.

Conclusions:

• 5-HT plays a crucial role in mitigating acceleration-induced cognitive deficits.
• Supplementation with 5-HT ameliorates these deficits by rebalancing gut microbiota and suppressing hippocampal neuroinflammation.
• These findings suggest 5-HT as a potential therapeutic target for gut-brain axis disorders.