According to Scientific American, scientists have been trying to grow human organs from scratch for well over a decade. These organoids are not fully formed functional organs but miniaturized versions that help researchers model various diseases and test therapies. These organoids engineered from scratch also include “mini-brains” or pea-sized clusters of lab-grown brain cells that assemble themselves into structures that resemble human brain tissue.
An organoid functioning like an actual brain helps scientists study various neurological and mental health disorders, such as epilepsy, stroke, and schizophrenia. However, getting a comprehensive glimpse inside these mini-brains has been a challenge – until now. A new study reveals the detailed internal anatomy of mini-brains for the first time.
What are Mini-Brains?
Mini-brains are used as a tool, allowing researchers to learn about how the brain develops, study disease, and test new medicines. According to Johns Hopkins, “Lab-grown miniature brains are poised to shake up drug testing for everything from Alzheimer’s disease to the Zika virus.” Consider this, recent technology to grow brain tissue from stem cells has enabled researchers to compare brain development in different primates. Another group of scientists developed a mini-brain with neural activity similar to that seen in a preterm infant. Personalized mini-brains can also be grown from stem cells generated from a sample of human hair or skin and could shed light on how brain disease progresses in an individual and how this person may respond to drugs.
A 3D Anatomy of the Mini-Brain
According to Neuroscience News, research from HEPIA and the Wyss Center for Bio and Neuroengineering has revealed the detailed internal anatomy of mini-brains for the first time. “Despite advances in growing mini-brains, it has been difficult to understand what is going on inside,’ states Adrien Roux, senior author on the paper. Typically, to look inside a mini-brain, scientists would have to slice it thinly and view it on a slide under a microscope, potentially causing damage to the sample. “Now, scientists and engineers have produced high-resolution 3D images of single neurons within intact mini-brains, revealing their remarkable complexity,” added Subashika Govindan, lead author on the paper.
Reducing Animal Testing & Advancing Medical Research
The scientific team developed a custom module, including a custom sample holder and sensitive imaging detectors, for capturing 3D images of entire intact mini-brains without slicing them. The team was able to visualize and analyze the 3D morphology of specific neurons and their anatomical arrangement inside the mini-brains. Why is a detailed peek into mini-brains important? According to one researcher on the team, “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.” The new strategy could also allow imaging of large numbers of “mini-brains,” making it suitable for high-throughput screening for drug discovery or toxicity testing. According to the team, this 3D high-resolution look into mini-brains is reproducible and cost-effective, potentially helping to accelerate personalized medicine studies.
