Scientists say they’ve created the first 3D-printed brain tissue where neurons network and “talk” to each other.

The breakthrough could be an advance for studying neurological processes in the lab, say a team from the University of Wisconsin-Madison.

“This could be a hugely powerful model to help us understand how brain cells and parts of the brain communicate in humans,” said study lead author Su-Chun Zhang, a professor of neuroscience and neurology at UW–Madison’s Waisman Center.

“It could change the way we look at stem cell biology, neuroscience and the pathogenesis of many neurological and psychiatric disorders,” he added in a university news release.

Zhang’s team noted that researchers already have an organic model for brain research, called brain organoids. But organoids grow with much less cellular organization and inter-connective ability than the new 3D-printed tissue.

With his lab’s new process, “we printed the cerebral cortex and the striatum, and what we found was quite striking,” Zhang said. “Even when we printed different cells belonging to different parts of the brain, they were still able to talk to each other in a very special and specific way.”

Reporting Feb. 1 in the journal Cell Stem Cell, the Madison team said their 3-D printing technology has improved on prior attempts to create 3D-printed brain tissue.

The Madison lab’s tissues include neurons created from stem cells, and they are oriented in a different pattern than was used in prior attempts.

The cells are also embedded in a softer form of “bio-ink” gel than was used previously.

As Zhang explained it, “the tissue still has enough structure to hold together, but it is soft enough to allow the neurons to grow into each other and start talking to each other.”

This means that disparate brain cells in the new tissue use neurotransmitter chemicals to send signals to each other. They can even form neural networks, as is seen in living brains, Zhang’s group said.

“Our lab is very special in that we are able to produce pretty much any type of neurons at any time. Then we can piece them together at almost any time and in whatever way we like,” Zhang added. “Because we can print the tissue by design, we can have a defined system to look at how our human brain network operates. We can look very specifically at how the nerve cells talk to each other under certain conditions because we can print exactly what we want.”

The Madison crew believe their new 3D-printed tissue could be easily used by most research labs. It does not require special equipment and scientists can investigate neurological processes using standard microscopes.

Potential applications include studies into Down syndrome, Alzheimer’s disease, brain development and the creation of experimental drugs, the researchers said.

The key breakthrough here is that the 3D-printed tissue forms real neurological networks, Zhang said.

“In the past, we have often looked at one thing at a time, which means we often miss some critical components. Our brain operates in networks,” he said. “We want to print brain tissue this way because cells do not operate by themselves. They talk to each other. This is how our brain works, and it has to be studied all together like this to truly understand it.”

More information

Find out more about how the brain works at Johns Hopkins Medicine.

SOURCE: University of Wisconsin-Madison, news release, Feb. 1, 2024