Previously in Science First, we introduced you to “mini-brain” models: brain organoids derived from human stem cells that were reprogrammed into cell types found in the brain. In the past month, two new studies were published that have greatly expanded our understanding of the potential of these models. These studies have confirmed that organoids can be used to effectively recreate the early stages of human neurodevelopment in vitro.
According to Dr. Timothy O’Brien of the University of Minnesota, the new studies “give us unprecedented ways of looking at a human brain and its development.” Dr. O’Brien also noted that the studies “uncover[ed] more layers of complexity, showing that these things really do look like human brains.”
Scientists can use brain organoid models to learn more about human brain development and how it can relate to neurodevelopmental and neuropsychiatric conditions. This increased understanding may potentially help identify drugs that can be used to treat different brain disorders. While animals are often used as models for human neurological diseases, they have not been effective because of major biological differences between animals and humans.
Therefore, many researchers have begun developing more efficacious, human-relevant approaches and have continued to refine cell-based models.
One of the new studies showed that brain organoids could be developed over an extended period. Over the course of nine months, the models developed more mature and diverse neurons than those established in previous models. Importantly, the neurons were functional, too. They formed circuits, which suggests they may be helpful for modeling higher order functions of the brain.
The other recent study set out to first make spheroids of different brain regions. Spheroids of two different brain regions were then fused together to help researchers better understand how the regions interact. This in vitro study captured elaborate developmental processes better than existing models.
We are encouraged to see human organoids being utilized across many areas of research, and we look forward to the full potential of these continually improving models being realized. These human-relevant tools will make a tremendous contribution to science and will significantly impact the use of animal models, which lack translational potential and may hinder progress in these important areas of research.
READ MORE: “Mini-brains” are helping researchers understand the Zika virus.
Source: Begley, S. “‘Mini-Me’ Brains Mimic Disease, Raise Hope for Eventual Therapies,” Scientific American, April 27, 2017.