FIG. 5.
MSC-derived cells display excitable responses to infrared laser stimulus. (A) Shows QDot-positive and -negative cells after loading with Ca2+-sensitive dye Fluo-4 AM. Two QDot-positive (ie, nasal MSC-derived) cells and one QDot-negative cell were selected to analyze their responses to infrared radiation (IR) stimulation for 1 min at 1,893 nm, 1 pps, and 1,017 mJ of radiant energy. Normalized fluorescence values were plotted over time. Traces (B) and (C) show the IR-evoked [Ca2+]i transients in the two selected QDot-positive cells. Trace (D) shows the response of a QDot-negative endogenous cell, which can be a spiral ganglion neuron or a glial cell. Responses obtained in traces (B–D) are similar to the ones obtained in excitable cells such as neurons or cardiomyocytes. Color images available online at www.liebertpub.com/scd