Sodium-Calcium Exchanger Can Account for Regenerative Ca²⁺ Entry in Thin Astrocyte Processes.

ABSTRACT: Calcium transients in thin astrocytic processes can be important in synaptic plasticity, but their mechanism is not completely understood. Clearance of synaptic glutamate leads to increase in astrocytic sodium. This can electrochemically favor the reverse mode of the Na/Ca-exchanger (NCX) and allow calcium into the cell, accounting for activity-dependent calcium transients in perisynaptic astrocytic processes. However, cytosolic sodium and calcium are also allosteric regulators of the NCX, thus adding kinetic constraints on the NCX-mediated fluxes and providing for complexity of the system dynamics. Our modeling indicates that the calcium-dependent activation and also calcium-dependent escape from the sodium-mediated inactive state of the NCX in astrocytes can form a positive feedback loop

SUBMITTER: Brazhe AR 

PROVIDER: S-EPMC6102320 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature