Researchers at the Wyss Center in Geneva and collaborators have developed novel imaging and labeling techniques to view the internal structure of brain spheroids, and observe the morphology of single neurons in 3D. Brain spheroids, which the researchers term “mini brains,” are a cluster of different types of brain cells, and are cultured from induced pluripotent stem cells. Used as a research tool, including in drug development, the mini brains will be more useful to researchers if their structure can be accurately assessed without having to cut them into slices for microscopy.
Brain spheroids have a wide array of uses, from testing drugs to studying neurological disease. However, at present, if researchers want to look at their internal structure they typically have to cut them into small sections and place these on microscope slides.
Unfortunately, this makes it very difficult to accurately determine their internal structure or observe the structure of individual neurons. Moreover, the sectioning process can damage the spheroids, making subsequent imaging less valuable and informative.
“Despite advances in growing ‘mini-brains’, it has been difficult to understand in detail what is going on inside – until now,” said Professor Adrien Roux a researcher involved in the study.
“Typically, to look inside a ‘mini-brain’, we slice it thinly and view it on a slide under a microscope,” said Dr Subashika Govindan, another researcher involved in the study. “This is a slow process that can damage the sample. Now, for the first time, we have produced high resolution 3D images of single neurons within intact ‘mini-brains’, revealing their remarkable complexity.”
To address this, these researchers have developed an array of imaging techniques to allow them to peer inside the intact spheroids. These involve a method to make the spheroids completely transparent, so that imaging can take place. The researchers also used viral vectors to label specific neurons, allowing them to create striking 3D images of individual neurons within the spheroids.
“Human ‘mini-brains’ have a life span of more than a year and, with our new ability to visualize them in more detail, we can envision benefits such as reducing some animal testing,” said Dr Laura Batti, another researcher involved in the study.
See a video about the study below:
Study in Frontiers in Bioengineering and Biotechnology: Mass Generation, Neuron Labeling, and 3D Imaging of Minibrains
Via: Wyss Center