Probing the Fractal Pattern of Heartbeats in Drosophila Pupae by Visible Optical Recording System

• Published in: Scientific reports Vol. 6; no. 1; p. 31950
• Main Authors: Lin, Chen, Chang, Yi-Chung, Cheng, Ya-Chen, Lai, Po-Jung, Yeh, Chien-Hung, Hsieh, Wan-Hsin, Hu, Kun, Wu, June-Tai, Lee, Hsiu-Hsiang, Lo, Men-Tzung, Ho, Yi-Lwun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 18.08.2016; Nature Publishing Group
• Subjects: 631/1647/245/2225; 631/1647/245/2226; Adenosine triphosphatase; Animals; Ca2+-transporting ATPase; Calcium (intracellular); Calcium (reticular); Calcium - metabolism; Drosophila - growth & development; Drosophila - physiology; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Fractals; Heart; Heart Rate; Humanities and Social Sciences; Insects; Larva - physiology; Light effects; multidisciplinary; Optical Devices; Principal Component Analysis; Radiation; Sarcoplasmic Reticulum Calcium-Transporting ATPases - metabolism; Scaling; Science
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep31950

Judiciously 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 Ca 2+ levels, the expression of sarco-endoplasmic reticulum Ca 2+ -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).