Fig. 4.

Contractions of neonatal rat cardiomyocytes pre and post laser stimulation with a radiant exposure of 8 mJ/cm² and an irradiation time of 10 ms. While the laser stimulation did not affect the contractile behavior of the examined cardiomyocyte in HBSS-Ca²⁺ (a), it induced significant increases of the contraction frequency in cardiomyocytes in HBSS + Ca²⁺ (b) (referring to Visualization 2 ^{(13.6MB, MP4)} ). Cardiomyocytes in HBSS + hCa²⁺ exhibited higher contraction frequencies after laser treatment as well (c) (referring to Visualization 3 ^{(13.6MB, MP4)} ). Laser irradiation occurred every 15.6 s (red arrows), every peak represents one contraction of the examined cardiomyocyte. Data shown represents the exemplary contractile behavior of one single out of at least n = 7 examined cells or set of cells in HBSS-Ca²⁺, HBSS + Ca²⁺ and HBSS + hCa²⁺, respectively. Narrow peaks are laser light detected by the camera if it was coincident with the frame acquisition.