Lin, ChenChang, Yi-ChungCheng, Ya-ChenLai, Po-JungYeh, Chien-HungHsieh, Wan-HsinHu, KunWu, June-TaiLee, Hsiu-HsiangLo, Men-TzungHo, Yi-Lwun2016-10-112016Lin, C., Y. Chang, Y. Cheng, P. Lai, C. Yeh, W. Hsieh, K. Hu, et al. 2016. “Probing the Fractal Pattern of Heartbeats in Drosophila Pupae by Visible Optical Recording System.” Scientific Reports 6 (1): 31950. doi:10.1038/srep31950. http://dx.doi.org/10.1038/srep31950.2045-2322http://nrs.harvard.edu/urn-3:HUL.InstRepos:29002394Judiciously tuning heart rates is critical for regular cardiovascular function. The fractal pattern of heartbeats — a multiscale regulation in instantaneous fluctuations — is well known for vertebrates. The most primitive heart system of the Drosophila provides a useful model to understand the evolutional origin of such a fractal pattern as well as the alterations of fractal pattern during diseased statuses. We developed a non-invasive visible optical heart rate recording system especially suitable for long-term recording by using principal component analysis (PCA) instead of fluorescence recording system to avoid the confounding effect from intense light irradiation. To deplete intracellular Ca2+ levels, the expression of sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) was tissue-specifically knocked down. The SERCA group shows longer heart beat intervals (Mean ± SD: 1009.7 ± 151.6 ms) as compared to the control group (545.5 ± 45.4 ms, p < 0.001). The multiscale correlation of SERCA group (scaling exponent: 0.77 ± 0.07), on the other hand, is weaker than that of the control Drosophila (scaling exponent: 0.85 ± 0.03) (p = 0.016).en-USJournal Article2016-10-1110.1038/srep31950