Scientists have built a tissue replica of our cognitive centre in the hope of decoding how this complex organ works.
It looks like a failed attempt at a very small rainbow birthday cake, with six concentric circles of colour. But it’s actually one of the greatest advances in brain science: 3D brainlike tissue.
The human brain remains largely mysterious, with billions of dollars being spent on improving our understanding of this cognitive centre.
In a study published in the journal Proceedings of the National Academy of Sciences this week, the authors detail how they managed to create “stiff and porous scaffolds made of a silk protein called fibroin, and then filled the scaffolds with neurons as well as soft collagen gels that provided structural and biochemical support to the cells”. It has similar functions and structure to a rodent brain, and they could keep it alive in the laboratory for two months.
The six sections of the “doughnut” cake-brain mimic the six layers of the human brain, and the researchers populated each section with different neurons.
This artificial brain – developed at the Tissue Engineering Resource Centre at Tufts University in Boston – can help researchers to study what happens to the brain in head trauma injuries, as well as its responses to medication. Dr David Kaplan, director of the centre, led the research and development of the brain.
“With the system we have, you can essentially track the tissue response to traumatic brain injury in real time,” said Kaplan. “Most importantly, you can also start to track repair and what happens over longer periods of time.”
At the moment, scientists either study this in animals (where the brain is subsequently dissected and analysed) or by observing neurons in a Petri dish (this two-dimensional interaction does not capture the complexity of the brain’s structure).
Kaplan emphasised the importance of the brainlike tissue’s longevity for studying other brain disorders. “The fact that we can maintain this tissue for months in the lab means we can start to look at neurological diseases in ways that you can’t otherwise because you need long time frames to study some of the key brain diseases,” he said.
The United States’s National Institutes of Health, which funded the research through the National Institute of Biomedical Imaging and Bioengineering, said: “The key to generating the brainlike tissue was the creation of a novel composite structure that consisted of two biomaterials with different physical properties: a spongy scaffold made out of silk protein and a softer, collagen-based gel. The scaffold served as a structure on to which neurons could anchor themselves, and the gel encouraged axons to grow through it.”
“This work is an exceptional feat,” said Dr Rosemarie Hunziker, programme director of tissue engineering at the National Institute of Biomedical Imaging and Bioengineering. “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.”
Understanding more about the brain could enable scientists to treat brain diseases such as Alzheimer’s and head injuries, or even to develop new computers. This is just the beginning.