Investigation of the Ca2+ response of human hNT astrocytes to laser removal of cellular processes.

We demonstrate, for the first time, UV laser ablative microsurgery as a method for pruning astrocytic processes from live hNT astrocytic networks in vitro. Calcium fluorescence imaging was used to evaluate the cellular response to process ablation. The results showed that ablation of astrocyte processes induced an immediate increase in intracellular calcium level which propagated through the cells cytoplasm as a wave originating from the ablation site. The increased intracellular calcium dissipated from the body of the cell but remained high in the vicinity of the ablation site. Cell viability post ablation was confirmed by observing the integrity of the cell membrane. Ablation of astrocytic processes did not compromise cell viability whereas ablation of the cytoplasm using the same laser energy resulted in cell lysis.