The paper describes the technique of high-frequency ultrasound examination in vivo of the cardiovascular system of lower vertebrates at the early stages of their development. The basis of the experimental setup used in the research is a scanning acoustic microscope with a spatial resolution of 20 μm, combined with an optical inverted microscope. It is shown that the spatial and temporal resolution of the sonographic module is sufficient for visualizing the structure of the heart and recording the movement of its components. Experimental work was carried out on individuals of Misgurnus fossilis and Danio rerio at the larval stage of development. The studied organisms after immobilization were placed in the immersion cell of the sonographic module, and the ultrasound data was recorded depending on the spatial coordinates and time. The received ultrasound scans clearly show the structural elements of the heart, they differ in the reflections of ultrasound signals from the walls of the heart and blood elements. The scans reveal the frequency of the ultrasonic spatio-temporal signal in terms of the temporal variable, which corresponds to the rhythm of cardiac activity. It has been demonstrated that the selected ultrasound signals can be used to determine the trajectory of the heart walls in its various regions, as well as to measure the blood flow velocity. It was found that the vertical component of the velocity of blood elements is approximately 0.8 and 0.08 mm / s during systole and in pause, respectively.
lower vertebrates, cardiovascular system, sonography, scanning acoustic microscope
1. Giardoglou P., Beis D. On Zebrafish Disease Models and Matters of the Heart. Biomedicines, 2019, vol. 7, no. 1, p. 15.
2. Burlakov A.B., Machihin A.S., Hohlov D.D., Gadzaov A.F. Ispol'zovanie akustooptiki dlya vyyavleniya lokal'noy geterogennosti zheltka v period podgotovki k poyavleniyu spontannoy dvigatel'noy aktivnosti u embrionov v'yuna, Misgurnus fossilis. Biomedicinskaya radioelektronika, 2019, № 2, s. 47-53. @@Burlakov A.B., Machikhin A.S., Khokhlov D.D., Gadzaov A.F. Using acousto-optics to identify local heterogeneity of the yolk in preparation for the appearance of spontaneous locomotor activity in embryos of the loach, Misgurnus fossilis. Biomeditsinskaya radioelektronika, 2019, no. 2, pp.47-53. (In Russ.)
3. Kostomarova A.A. Ob'ekty biologii razvitiya. M.: Nauka, 1975, c. 321. @@Kostomarova A.A. Developmental biology objects. M.: Nauka, 1975, p. 321. (In Russ.)
4. Daetwyler S., Günther U., Modes C.D., Harrington K., Huisken J. Multi-sample SPIM image acquisition, processing and analysis of vascular growth in zebrafish. Development, 2019, vol. 146, no. 6, dev173757, pp. 1-10.
5. Keller P.J., Schmidt A.D., Wittbrodt J., Stelzer E.H.K. Reconstruction of Zebrafish Early Embryonic Development by Scanned Light Sheet Microscopy. Science, 2008, vol. 322, no. 5904, pp. 1065-1069.
6. Salman H.E., Yalcin H.C. Advanced blood flow assessment in Zebrafish via experimental digital particle image velocimetry and computational fluid dynamics modeling. Micron, 2020, vol. 130, no. 3, 10280.
7. Sun L., Lien C.L., Xu X., Kirk Shung. K. In Vivo Cardiac Imaging of Adult Zebrafish Using High Frequency Ultrasound (45-75 MHz). Ultras. Med. Biol. 2008, vol. 34, no. 1, pp. 31-39.
8. Huang C.C., Su T.H., Shih C.C. High-resolution tissue Doppler imaging of the zebrafish heart during its regeneration. Zebrafish, 2015, vol. 12, no. 1, pp. 48-57.
9. Wang L.W., Huttner I.G., Santiago C.F, Kesteven S.H., Yu Z.Y., Feneley M.P., Fatkin D. Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models. Dis. Model. Mech., 2017, vol. 10, no. 1, pp. 63-76.
10. Fanga Y., Suna Y., Luo C., Gu J., Shi Z., Lu G., Silvestre J.-S., Chen Z. Evaluation of cardiac dysfunction in adult zebrafish using high frequency echocardiography. Life Sciences, 2020, vol. 253, p. 117732.
11. Evangelisti A., Schimmel K., Joshi S., Shah K., Fisch S., Alexander K.M., Liao R., Morgado I. High-Frequency Ultrasound Echocardiography to Assess Zebrafish Cardiac Function. J. Vis. Exp., 2020, Mar 12, vol. 157, e60976.
12. Titov S.A. Burlakov A.B., Zinin P.V., Bogachenkov A.N. Izmerenie skorosti zvuka v tkanyah embrionov kostistyh ryb. Izv. RAN. Ser Fizicheskaya, 2021, tom 85, № 1, s. 140-144. @@Burlakov A.B., Titov S.A., Zinin P.V., Bogachenkov A.N. Measuring the Speed of Sound in Tissues of Teleost Fish Embryos. Bulletin of the Russian Academy of Sciences: Physics, 2021, vol. 85, no. 1, pp. 103-107. (In Russ.)
13. Burlakov A.B., Titov S.A., Bogachenkov A.N. Ultrasonic monitoring of early development of lower vertebrate embryos. J. of Physics: Conf. Series, 2020, vol. 1679.
