KCC2-dependent steady-state intracellular chloride concentration and pH in cortical layer 2/3 neurons of anesthetized and awake mice

• Verfasser: Boffi, Juan C. [VerfasserIn]
• Verfasser: Knabbe, Johannes [VerfasserIn]
• Verfasser: Kaiser, Michaela [VerfasserIn]
• Verfasser: Kuner, Thomas [VerfasserIn]
• Titel: KCC2-dependent steady-state intracellular chloride concentration and pH in cortical layer 2/3 neurons of anesthetized and awake mice
• Verf.angabe: Juan C. Boffi, Johannes Knabbe, Michaela Kaiser and Thomas Kuner
• Fussnoten: Gesehen am 13.04.2018
• Titel Quelle: Enthalten in: Frontiers in cellular neuroscience
• Jahr Quelle: 2018
• Band/Heft Quelle: 12(2018) Artikel-Nummer 7, 14 Seiten
• ISSN Quelle: 1662-5102
• DOI: doi:10.3389/fncel.2018.00007
• Datenträger: Online-Ressource
• Sprache: eng
• SWB-PPN: 50200553X
• SWB-PPN:
  Universitätsbibliothek
• Lokale URL UB: Zum Volltext

Abstract

Neuronal intracellular Cl- concentration ([Cl-]i) influences a wide range of processes such as neuronal inhibition, membrane potential dynamics, intracellular pH (pHi) or cell volume. Up to date, neuronal [Cl-]i has predominantly been studied in model systems of reduced complexity. Here, we implemented the genetically encoded ratiometric Cl- indicator Superclomeleon (SCLM) to estimate the steady-state [Cl-]i in cortical neurons from anesthetized and awake mice using 2-photon microscopy. Additionally, we implemented superecliptic pHluorin as a ratiometric sensor to estimate the intracellular steady-state pH (pHi) of mouse cortical neurons in vivo. We estimated an average resting [Cl-]i of 6 ± 2 mM with no evidence of subcellular gradients in the proximal somato-dendritic domain and an average somatic pHi of 7.1 ± 0.2. Neither [Cl-]i nor pHi were affected by isoflurane anesthesia. We deleted the cation-Cl- co-transporter KCC2 in single identified neurons of adult mice and found an increase of [Cl-]i to approximately 26 ± 8 mM, demonstrating that under in vivo conditions KCC2 produces low [Cl-]i in adult mouse neurons. In summary, neurons of the brain of awake adult mice exhibit a low and evenly distributed [Cl-]i in the proximal somato-dendritic compartment that is independent of anesthesia and requires KCC2 expression for its maintenance.