March 30 (UPI) -- Researchers from the University of Electronic Science and Technology of China said they witnessed the development of blood vessels in zebrafish embryos without disturbing the biological process with fluorescent tags or contrast agents.
"Zebrafish play an important role in biology, pharmacology, toxicology, and medicine. The cardio-cerebrovascular development of zebrafish is particularly critical to understand both brain disorders and cardiovascular diseases in humans," researchers wrote in the study, published in the journal Biomedical Optics Express.
The tag-free -- also known as label-free -- and contrast-free imaging of the zebrafish's development could be used to better understand brain and cardiovascular diseases in people, as zebrafish embryos are transparent, which makes them an excellent model for researchers studying how vertebrate organisms develop and grow.
The researchers used optical resolution photoacoustic microscopy, or ORPAM, to acquire images of vessel development in the embryos using sound, rather than fluorescence labels or contrast agents.
Fluorescence labels or contrast agents are generally required to see embryos' biological processes with the use of high-resolution optical imaging techniques such as confocal fluorescence microscopy and two-photon microscopy.
The ORPAM technique does not require contrast agents because it forms images by detecting ultrasonic waves that are created when molecules absorb light.
"We successfully visualized the development of the cardio-cerebrovascular system in the early embryonic stage of zebrafish," Lei Xi, a researcher at the University of Electronic Science and Technology of China, said in a press release. "Since the zebrafish remains one of the most important models to study human diseases, we believe that our work is important to understanding both brain disorders and cardiovascular diseases in humans."
The researchers also said they zoomed in to witness the formation of vessels associated with the development of the heart and the brain by using the technique's high-resolution mode.
"The ability to visualize dynamic development during the embryonic stage, when the blood vessels initially form and develop, brings the potential to use zebrafish to investigate various human cardiovascular and cerebrovascular diseases in the future," Xi said.