TY - JOUR
T1 - Assessments of Heart Rate and Sympathetic and Parasympathetic Nervous Activities of Normal Mouse Fetuses at Different Stages of Fetal Development Using Fetal Electrocardiography
AU - Kasahara, Yoshiyuki
AU - Yoshida, Chihiro
AU - Saito, Masatoshi
AU - Kimura, Yoshitaka
N1 - Funding Information:
We thank Kunihiro Koide, Shizu Shoji, and Chie Yoshida for assistance and technical advice, as well as Namareq Widatalla for English proofreading. We also thank Masatoshi Ukezono for advice about statistical analysis. The authors would like to thank Enago (www.enago.jp) for the English language review. Funding. This research was supported by the RIKEN Healthcare and Medical Data Platform Project; Grand-in-Aid for Scientific Research (C) KAKENHI, Japan (No. 20K09590); the Creative Interdisciplinary Research Project of Frontier Research Institute for Interdisciplinary Science, Tohoku University; and funding for basic medical research by Shiguredo Inc.
Funding Information:
This research was supported by the RIKEN Healthcare and Medical Data Platform Project; Grand-in-Aid for Scientific Research (C) KAKENHI, Japan (No. 20K09590); the Creative Interdisciplinary Research Project of Frontier Research Institute for Interdisciplinary Science, Tohoku University; and funding for basic medical research by Shiguredo Inc.
Publisher Copyright:
© Copyright © 2021 Kasahara, Yoshida, Saito and Kimura.
PY - 2021/4/8
Y1 - 2021/4/8
N2 - Heart rate is controlled by the activity of the autonomic nervous system: the sympathetic and parasympathetic nervous systems increase and suppress heart rate, respectively. To evaluate the activity of the autonomic nervous system, it is possible to determine heart rate variability using electrocardiography (ECG). During the fetal period, the heart and autonomic nerves develop in coordination; however, physiological changes, including autonomic nervous activities that occur during the fetal stage, remain largely unknown. Therefore, in this study, we measured ECG signals of mouse fetuses using our established method to evaluate the development of heart rate and autonomic nervous activity at different fetal developmental stages. We found that heart rate was significantly increased in fetal mice at embryonic day (E) 18.5 compared with that at E13.5, E15.5, and E17.5, indicating that fetal heart rate increases only at the stage immediately prior to birth. Interestingly, fetal parasympathetic nervous activity was reduced at E17.5 and E18.5 compared with that at E13.5, whereas fetal sympathetic nervous activity remained unchanged, at least from E13.5 to E18.5. These results indicate that parasympathetic activity rather than sympathetic activity affects fetal heart rate and that the decrease in parasympathetic activity toward the end of pregnancy could result in the observed increase in fetal heart rate.
AB - Heart rate is controlled by the activity of the autonomic nervous system: the sympathetic and parasympathetic nervous systems increase and suppress heart rate, respectively. To evaluate the activity of the autonomic nervous system, it is possible to determine heart rate variability using electrocardiography (ECG). During the fetal period, the heart and autonomic nerves develop in coordination; however, physiological changes, including autonomic nervous activities that occur during the fetal stage, remain largely unknown. Therefore, in this study, we measured ECG signals of mouse fetuses using our established method to evaluate the development of heart rate and autonomic nervous activity at different fetal developmental stages. We found that heart rate was significantly increased in fetal mice at embryonic day (E) 18.5 compared with that at E13.5, E15.5, and E17.5, indicating that fetal heart rate increases only at the stage immediately prior to birth. Interestingly, fetal parasympathetic nervous activity was reduced at E17.5 and E18.5 compared with that at E13.5, whereas fetal sympathetic nervous activity remained unchanged, at least from E13.5 to E18.5. These results indicate that parasympathetic activity rather than sympathetic activity affects fetal heart rate and that the decrease in parasympathetic activity toward the end of pregnancy could result in the observed increase in fetal heart rate.
KW - autonomic nervous system
KW - fetal ECG
KW - fetal development
KW - heart rate
KW - heart rate variability
KW - parasympathetic nervous system
KW - sympathetic nervous system
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UR - http://www.scopus.com/inward/citedby.url?scp=85104578766&partnerID=8YFLogxK
U2 - 10.3389/fphys.2021.652828
DO - 10.3389/fphys.2021.652828
M3 - Article
AN - SCOPUS:85104578766
VL - 12
JO - Frontiers in Physiology
JF - Frontiers in Physiology
SN - 1664-042X
M1 - 652828
ER -