Scientists often use mice in experiments which aim to seek a better understanding of the human body as well as gain insights on certain health conditions and it is apparently for the purpose of learning more about the different parts of the body and how they work that scientists have come up with a method that can make the body of laboratory mice transparent.
In an experiment described in the study "Single-Cell Phenotyping within Transparent Intact Tissue through Whole-Body Clearing" which was published in the journal Cell on July 31, Viviana Gradinaru, from the Division of Biology and Biological Engineering of the California Institute of Technology in Pasadena, and colleagues found a way to make see-through mice albeit it involves euthanizing the animals and removing their skins.
For the process, the researchers pumped a series of chemicals into the mice's circulatory system and these chemicals include those that hold the animal's tissue in place and some that eliminate the fats that cause the tissues to block light. With this technique, the researchers were able to make the peripheral organs of the mice transparent in just two days and the whole body transparent in two weeks.
In order to have a better view of the microscopic structures of the animals' brain and body, the researchers also removed large bones that block the view of some cells as well as injected fluorescent chemicals that would highlight certain cells.
"Herein we introduce PARS, a method that renders intact whole-organisms transparent for imaging with single-cell resolution while preserving fluorescent and protein-based signals and tissue architecture," the researchers wrote. "PARS holds the potential to refine our understanding of peripheral nerves at their target whole organs."
Although there are other options that would allow researchers to study organs in microscopic details, dissecting and slicing organs or generating 3D models of these organs can be inaccurate. Gradinaru said that the new process could be useful in projects that aim to have a detailed mapping of the nervous system as well as in assessing the spread of cancer in laboratory animals. She also said that it could help improve treatments for certain health problems.
"For example, there are instances where electrical stimulation is used to help treat Parkinson's, bladder control or pain and those electrical stimulators are applied to nerves throughout the body," Gradinaru said. "Knowing exactly where those nerves run to and from, and their functions, would improve those treatments."