Astrocyte Ca²⁺-evoked ATP release regulates myelinated axon excitability and conduction speed.

ABSTRACT: In the brain’s gray matter, astrocytes regulate synapse properties, but their role is unclear for the white matter, where myelinated axons rapidly transmit information between gray matter areas. We found that in rodents, neuronal activity raised the intracellular calcium concentration ([Ca²⁺]_i) in astrocyte processes located near action potential–generating sites in the axon initial segment (AIS) and nodes of Ranvier of myelinated axons. This released adenosine triphosphate, which was converted extracellularly to adenosine and thus, through A_2a receptors, activated HCN2-containing cation channels that regulate two aspects of myelinated axon function: excitability of the AIS and speed of action potential propagation. Variations in astrocyte-derived adenosine

SUBMITTER: Lezmy J 

PROVIDER: S-EPMC7611967 | biostudies-literature | 2021 Oct

REPOSITORIES: biostudies-literature