Deficient Memory, Long-Term Potentiation, and Hippocampal Synaptic Plasticity in Galectin-4-Deficient Mice.

Area of Science:

• Neuroscience
• Microbiology
• Gut-Brain Axis Research

Background:

• The gut microbiota influences brain function via the microbiota-gut-brain axis.
• The impact of commensal microbiota shifts on neurological conditions is not well understood.
• Galectin-4, an intestinal lectin, plays a role in controlling bacterial infections.

Purpose of the Study:

• To investigate the role of galectin-4 in modulating commensal microbiota.
• To explore if physiological variations in commensal microbiota contribute to neurological conditions.
• To examine the impact of galectin-4 deficiency on cognitive and affective behaviors.

Main Methods:

• 16S ribosomal RNA sequencing for gut microbiota analysis.
• Behavioral tests for cognitive and affective function assessment.
• Electrophysiology, immunofluorescence, Western blot, and RNA sequencing for hippocampal analysis.
• Golgi-Cox staining and electron microscopy for dendritic spine and synapse evaluation.

Main Results:

• Galectin-4 knockout mice exhibited altered commensal microbiota without pathogens.
• These mice showed deficient memory formation and impaired hippocampal long-term potentiation (LTP).
• Synaptic alterations, including reduced AMPA receptor activation, lower dendritic spine density, and altered postsynaptic densities, were observed.

Conclusions:

• Galectin-4 modulates commensal bacteria composition.
• Absence of galectin-4 leads to gut microbial changes, synaptic alterations, and memory deficits.
• Endogenous microbiota variations may contribute to neurological pathologies.