Scientists know a lot about the human body, yet much of the human brain is still a mystery. However, in a step furthering brain research, a group of bioengineers from Tufts University have created a three-dimensional functional model of brain tissue made from rat cells. Not only that, but this brain tissue functions like a real brain and its neurons respond to both chemical and physical stimuli.
In the study, the brain tissue remained "alive" for more than two months, even after researchers deliberately dropped weights on it. Such tests are critical in understanding how the brain functions after severe injury, and the artificial brain responded with neural activity similar to what previous research showed in animals with damaged brains.
"This work is an exceptional feat," says Dr Rosemarie Hunziker, program director of Tissue Engineering at the National Institute of Biomedical Imaging and Bioengineering, which funded the project . "It combines a deep understanding of brain physiology with a large and growing suite of bioengineering tools to create an environment that is both necessary and sufficient to mimic brain function."
Scientists have grown neurons in the lab before, in petri dishes, but such experiments cannot replace working with something more structurally complex and built in three dimensions. Researchers have also attempted growing neurons with a 3D gel, but those models didn't survive long enough for functionality.
"There are few good options for studying the physiology of the living brain, yet this is perhaps one of the biggest areas of unmet clinical need when you consider the need for new options to understand and treat a wide range of neurological disorders associated with the brain," says David Kaplan, Ph.D., from Tufts University. "To generate this system that has such great value is very exciting for our team."
The researchers used a spongy scaffold with a collagen-based gel for the brain's structure. This frame gave the neurons something to hold onto. Grey and white matter compartments surrounded that with neurons taken from a rat brain. More collagen-based gel went in the middle of the simulated brain, sort of like a jelly donut.
Once the brain was complete and functional, researchers performed tests on it, including dropping a weight on the brain. The tissue responded by releasing a neurotransmitter known to follow brain damage, along with electrical activity associated with trauma. Scientists hope that by being able to track brain functioning in response to injury in real-time, we'll gain a better understanding of what happens during brain trauma.
