In Vivo Neocortical [K]o Modulation by Targeted Stimulation of Astrocytes

Int J Mol Sci. 2021 Aug 12;22(16):8658. doi: 10.3390/ijms22168658.


A normally functioning nervous system requires normal extracellular potassium ion concentration ([K]o). Throughout the nervous system, several processes, including those of an astrocytic nature, are involved in [K]o regulation. In this study we investigated the effect of astrocytic photostimulation on [K]o. We hypothesized that in vivo photostimulation of eNpHR-expressing astrocytes leads to a decreased [K]o. Using optogenetic and electrophysiological techniques we showed that stimulation of eNpHR-expressing astrocytes resulted in a significantly decreased resting [K]o and evoked K responses. The amplitude of the concomitant spreading depolarization-like events also decreased. Our results imply that astrocytic membrane potential modification could be a potential tool for adjusting the [K]o.

Keywords: astrocyte; astrocyte membrane potential; extracellular potassium concentration; halorhodopsin; hyperpolarization.

MeSH terms

  • Animals
  • Archaeal Proteins / genetics
  • Archaeal Proteins / metabolism
  • Astrocytes / physiology*
  • Cell Membrane
  • Halobacteriaceae / genetics
  • Halobacteriaceae / metabolism*
  • Halorhodopsins / genetics*
  • Halorhodopsins / metabolism
  • Membrane Potentials
  • Mice
  • Neocortex / chemistry*
  • Optogenetics
  • Potassium / metabolism*


  • Archaeal Proteins
  • Halorhodopsins
  • Potassium

Supplementary concepts

  • Natronomonas