Journal Article

Astrocyte Fabp7 modulates nocturnal seizure threshold and activity-dependent gene expression in mouse brain

Davis, Christopher J, Gerstner, Jason R, Ferraro, Thomas N, Flores, Carlos C, Owada, Yuji, Lee, Yool, Schroeder, Wheaton L, Lefton, Micah

2025

Overview

Epileptic seizures often track with time of day and/or changes in vigilance state; however, specific molecular and cellular mechanisms driving the ictal and temporal associations are lacking. Astrocytes are a type of glial cell known to modulate neuronal excitability and circadian rhythms. These cells also abundantly express fatty acid–binding protein 7 (Fabp7), a clock-driven molecule necessary for normal sleep regulation, lipid signaling, and gene transcription. To determine whether Fabp7 influences time-of-day-dependent seizure susceptibility, we tested male C57/BL6N wild-type (WT) and Fabp7 knockout (KO) mice using electroshock seizure threshold. Compared with WT mice, Fabp7 KO mice exhibited markedly higher general- and maximal-electroshock seizure thresholds (GESTs and MESTs, respectively) during the dark phase, but not the light phase. We used RNA-seq to determine the role of Fabp7 in activity-dependent gene expression in nocturnal seizures and compared genome-wide mRNA expression in cortical/hippocampal tissue collected from WT-MEST and Fabp7 KO-MEST mice with WT-SHAM and Fabp7 KO-SHAM mice during the dark period. Whereas significant differential expression of immediate early genes was observed in WT-MEST compared with WT-SHAM, this effect was blocked in the Fabp7 KO-MEST versus Fabp7 KO-SHAM. Gene ontology and pathway analysis of all groups revealed significant overlap between WT-MEST:WT-SHAM and Fabp7 KO-SHAM:WT-SHAM comparisons, suggesting basal mRNA levels of core molecular and cellular mechanisms in the brain of Fabp7 KO approximate postictal WT brain. Together, these data suggest that Fabp7 regulates time-of-day-dependent neural excitability and that neural activity likely interacts with astrocyte Fabp7-mediated signaling cascades to influence activity-dependent gene expression.

• Publisher: Oxford University Press
• Subject: Astrocytes / Comparative analysis / Fatty acids / Gene expression / Genes / Genetic aspects / Genetic research / Genetic transcription / Health aspects / Mice / Protein binding / Risk factors / RNA / Seizures (Medicine)