Astrocyte Kir4.1 expression level territorially controls excitatory transmission in the brain
Olga Tyurikova, Olga Kopach, Kaiyu Zheng, Daman Rathore, Neela K. Codadu, Sheng-Yi Wu, Yi Shen, Robert E. Campbell, Robert C. Wykes, Kirill E. Volynski, Leonid P. Savtchenko, Dmitri A. Rusakov
Abstract
entry and release probability at excitatory synapses unless such synapses are surrounded by the Kir4.1-overexpressing astrocytes. Inside the territories of Kir4.1-overexpressing astrocytes, high-frequency afferent stimulation fails to induce long-term synaptic potentiation, and the high-potassium waves of cortical spreading depolarization are markedly attenuated. Biophysical exploration explains how astrocytes can regulate local potassium homeostasis by engaging Kir4.1 channels. Our findings thus point to a fundamental astrocytic mechanism that can restrain the activity-driven rise of excitability in brain circuits.