Comprehensive mapping of Epithelial Na+ channel α expression in the mouse brain

AbstractEpithelial sodium channel (ENaC) is responsible for regulating Na+ homeostasis. While its physiological functions have been investigated extensively in peripheral tissues, far fewer studies have explored its functions in the brain. Since our limited knowledge of ENaC ’s distribution in the brain impedes our understanding of its functions there, we decided to explore the whole-brain expression pattern of theScnn1a gene, which encodes the core ENaC complex component ENaC α. To visualizeScnn1a expression in the brain, we crossedScnn1a-Cre mice withRosa26-lsl-tdTomato mice. Brain sections were subjected to immunofluorescence staining using antibodies against NeuN or Myelin Binding Protein (MBP), followed by the acquisition of confocal images. We observed robust tdTomato fluorescence not only in the soma of cortical layer 4, the thalamus, and a subset of amygdalar nuclei, but also in axonal projections in the hippocampus and striatum. We also observed expression in specific hypothalamic nuclei. Contrary to previous reports, however, we did not detect significant expression in the circumventricular organs, which are known for their role in regulating Na+ balance. Finally, we detected fluorescence in cells lining the ventricles and in the perivascular cells of the median eminence. Our comprehensive mapping ofScnn1a-expressing cells in the brain will provide a solid foundation for further investigations of the physiological roles ENaC plays within the central nervous syste...

Source: Anatomy and Embryology - February 2, 2024 Category: Anatomy Source Type: research