Single-Cell Molecular Profiling Reveals Oral GABA Enhancing Synaptogenesis and Cognition

摘要

Objectives: The central nervous system has limited regenerative capacity, making it highly susceptible to damage. Processes like synaptogenesis and neurogenesis offer potential for recovery, wherein microglia and astrocytes play key roles. Anxiety disorders and cognitive deficits, often associated with neuroinflammation and neurotransmitter imbalances, are highly prevalent. This study aims to determine the molecular and cellular mechanisms by which oral GABA ameliorates cognitive deficits. Methods: Single-nucleus RNA sequencing of hippocampal tissue from long-term GABA treated mice and control mice were performed to generate gene expression and cell subtype profiles from millions of single cells to study the impact of long-term oral GABA to the functions of hippocampus, followed by Real-Time Quantitative PCR and behavioral validation. Robust Cell-Type Decomposition（RCTD）62 in the spacexr v2.2.1 package was used to deconvolve cell type compositions of each spot in the hippocampus. Results:① SnRNA-seq revealed coordination of neuroglial networks governing synaptogenesis and enrichment of DEGs of synapse-related functions in the hippocampus after long-term oral GABA administration, implicating an enhancement in cognition and memory.② A protective subtype of microglia cluster 4（Htr2c⁺,Tshz2⁺,Gpc6⁺） was identified, which exhibited enhancements in synaptic plasticity and anti-inflammatory regulation in GABA-mediated neuroprotection.③ Reconstruction of the spatial distribution signature of the microglia cluster 4 in the hippocampus were obtained successfully to confirm the cell type distribution.④ Real-Time Quantitative PCR confirmed the increases of synapse-related DEGs in SnRNA-seq, such as Grin2a, Camk2a, Cntnap2, Cntn5 and Slc8a1.⑤ Long-term oral GABA supplementation enhanced the cognitive and memory behaviors in Morris water maze and new object cognition tests. Conclusions: Long-term oral GABA enhances a synaptic protective protein profile and promotes a protective microglial subtype, thereby improving cognitive and memory behaviors in mice, suggesting a potential therapy for cognitive deficit-related disorders.

关键词

GABA / single cell transcriptomics / synaptogenesis / memory / cognition / microglia