Unveiling Ketamine's Influence on Astrocytic Kir4.1 Channels Through Multimodal Analysis: Confocal Microscopy, Immunocytochemistry, Fluorescence Analysis, and Electrophysiology.
Samo Pirnat, Katja Fink, Matjaž Stenovec, Marko Kreft, Robert Zorec
Methods in molecular biology (Clifton, N.J.) 2025 DOI: 10.1007/978-1-0716-4366-2_20 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Multifaceted investigation Peer reviewed |
|---|---|
| Population | Cultured rat and mouse cortical astrocytes |
| Intervention | Ketamine |
| Topics | Ketamine Esketamine |
| Keywords | Astrocytes Confocal microscopy Electrophysiology Kir4.1 Vesicle mobility Depression treatment Psychopharmacology Cellular biology Brain research |
| Key points | Ketamine modulates the dynamics, surface density, and voltage-activated currents of the Kir4.1 potassium channel in astrocytes. |
Abstract
Understanding the elusive mechanisms responsible for the therapeutic efficacy of ketamine in major depressive disorder (MDD) is crucial. Astrocytes play a vital role in regulating extracellular potassium concentration ([K+]o), which is essential for maintaining proper neuronal excitability and overall brain function. Dysregulation of [K+]o can lead to significant changes in neuronal activity, potentially contributing to the pathophysiology of various neurological and psychiatric conditions, including depression. To this end, we conducted a multifaceted investigation to elucidate the effects of ketamine on the inwardly rectifying K+ channel Kir4.1, which is critical for neuronal excitability and K+ homeostasis. Using cultured rat cortical astrocytes expressing fluorescently labeled Kir4.1 (Kir4.1-EGFP), we followed the dynamics of Kir4.1-EGFP vesicles after ketamine exposure. In addition, using live cell immunolabeling and patch-clamp assays in cultured mouse astrocytes, we investigated the effects of ketamine on Kir4.1 surface density and voltage-activated currents, similar to Ba2+ inhibition. This comprehensive methodological approach sheds light on the modulation of Kir4.1 dynamics by ketamine and thus provides valuable insights into its therapeutic mechanisms in MDD.