In beating cardiomyocytes, synchronized localized Ca2+ transients from thousands of active excitation-contraction coupling sites (ECC couplons) comprising plasma and sarcoplasmic reticulum membrane calcium channels are important determinants of the heart's performance. Nevertheless, our knowledge about their properties is limited by the lack of appropriate experimental and analysis strategies. We designed CaCLEAN to untangle fundamental characteristics of ECC couplons by combining the astronomer's CLEAN algorithm with known properties of calcium diffusion. CaCLEAN empowers the investigation of fundamental properties of ECC couplons in beating cardiomyocytes without pharmacological interventions. On the nanoscopic level of individual ECC couplons, we reveal their role in the negative amplitude-frequency relationship and b-adrenergic stimulation, including decreasing and increasing firing reliability, respectively. CaCLEAN combined with 3D confocal imaging of beating cardiomyocytes provides a functional 3D map of active ECC couplons (on average 17.000 per myocyte). CaCLEAN will further enlighten remodelling processes of ECC couplons underlying cardiac diseases.
- Peter Lipp
- Qinghai Tian
- Jia Guo
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Richard S Lewis, Stanford University School of Medicine, United States
© 2017, Tian et al.
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