Short-term continuous light exposure induces hippocampal rhythmic and functional alterations: a multi-timepoint...

Area of Science:

• Neuroscience
• Chronobiology
• Metabolomics

Background:

• Circadian rhythm disruption from light exposure impacts cognition.
• The specific effects on hippocampal metabolic oscillations are not well understood.

Purpose of the Study:

• Investigate the impact of short-term continuous light exposure on hippocampal circadian rhythms, metabolome, and cognition in mice.
• Identify key metabolic pathways and molecules affected by light-induced circadian disruption.

Main Methods:

• Established a 7-day continuous light exposure model in mice.
• Utilized behavioral assays, histopathology, qPCR for clock genes, and targeted time-series metabolomics.
• Analyzed circadian oscillations of clock genes and metabolites.

Main Results:

• Continuous light exposure disrupted circadian clock gene oscillations, impaired memory, and caused neuroinflammation.
• Metabolomic analysis revealed significant remodeling of circadian metabolite rhythms, with a 56.9% reduction in rhythmic metabolites.
• Identified GABA and vitamin B6 metabolism as key disrupted pathways, with GABA showing a phase delay and reduced amplitude.

Conclusions:

• Short-term continuous light exposure causes multi-level disruptions in the hippocampal circadian-metabolic network.
• GABA and vitamin B6 metabolism are critical nodes linking circadian disruption to cognitive impairment.
• Provides metabolomic insights into mechanisms of light pollution-associated cognitive deficits.