Here are the stem cell stories that caught our eye this week.

Two research photos really caught my eye this week and they happened to be of the same thing – mini-brains. Also referred to as brain organoids, mini-brains are tiny balls of nervous tissue grown from stem cells in the lab. They allow scientists to model early brain development and study how disease affects brain cells. Another awesome thing about mini-brains is how cool they look under a microscope.

Mini Brains Part 1

Mini-brain grown in a culture dish. (Photo by Collin Edington and Iris Lee, MIT)

I discovered the first photo in a blog by Dr. Francis Collins, the Director of the National Institutes of Health. He was featuring one of the winning images from the 2017 Koch Institute Image Awards at MIT. The mini-brain photo was taken by researchers Collin Edington and Iris Lee and took over 12 hours to make. Talk about dedication!

Collins revealed that growing mini-brains from stem cells is just the tip of the iceberg for this MIT team. The researchers have plans to grow other types of mini-organs and eventually combine them to make a “human on a chip”. This multi-organ technology will be extremely valuable for studying complex diseases like Alzheimer’s and Parkinson’s, which affect multiple systems in the body.

Mini Brains Part 2

Mini-brain. (Photo by Robert Krencik and Jessy Van Asperen)

The second photo of mini-brains is from a study published this week in Stem Cell Reports by researchers at the Houston Methodist Research Institute. The team has developed a more efficient and effective method for growing mini-brains from stem cells. Typically, the process takes weeks to grow the organoids and months to mature those organoids to the point where they develop the specific cell types and structures found in the human brain.

The Houston team found that maturing different types of brain cells from pluripotent stem cells separately and then combining these mature cells together produced mini-brains that more accurately represented the complexity of the human brain. The trick was to add the brain’s support cells, called astrocytes, to the mini-brains. The astrocytes effectively “accelerated the connections of the surrounding neurons.”

The studies first author, Robert Krencik, explained in a news release,

“We always felt like what we were doing in the lab was not precisely modeling how the cells act within the human brain. So, for the first time, when we put these cells together systematically, they dramatically changed their morphological complexity, size and shape. They look like cells as you would see them within the human brain, so now we can study cells in the lab in a more natural environment.”

Their method also cuts down the time it takes to make mini-brains which will hugely benefit neuroscience researchers who have passed on using mini-brains in their studies because of the cost and time it takes to grow them. Krencik explained,

“Normally, growing these 3-D mini brains takes months and years to develop. We have new techniques to pre-mature the cells separately and then combine them, and we found that within a few weeks they’re able to form mature interactions with each other. So, the length of time to get to that endpoint for studies is dramatically reduced with our system.”

The team plans to use this method to make patient-specific mini-brains from induced pluripotent stem cells to gain new insights into how disease affects the brain. They also hope to translate their mini-brain system into clinical trials to help patients regenerate brain damage or repair brain function.