It’s hard to study the human brain. It is the most complex in the animal kingdom with its massive collection of neurons, 80-100 billion to be exact, three times more than chimpanzees. Research relating our brains to the brains of mice and monkeys can only go so far. And because of this complexity, scientists often came up short when studying diseases such as schizophrenia, autism, and Alzheimer’s in the brains of monkeys and mice.

Enter minibrains.

Minibrains are small clusters of human brain cells that can be grown in a Petri dish. Floating through the agar, these small gray lumps don’t look particularly impressive, but they are allowing scientists to study actual living human brain tissue in ways they couldn’t before.

Researchers at UPenn are growing human brain organoids (sometimes called minibrains)

Growing these minibrains gives scientists a chance to study a host of psychological issues and diseases, and perhaps make advancements that they would not have made previously. Minibrains will even be sent to space to study how the human brain develops in zero-G.

But then came the surprise. These lab-grown brains started producing brainwaves.

These brainwaves, equivalent to brain wave patterns in a pre-term infant, were seen by a group of researchers at the University of California San Diego. They reported in a recent paper in Cell Stem Cell that these minibrains began showing neural activity after two months, and in four to six months, they reached levels of neural activity never before seen in a lab. At ten months, they were equivalent to pre-term babies, complete with lulls and flutters of activity.

Researchers at UPenn are growing human brain organoids (sometimes called minibrains)


Minibrains are created by using stem cells, in this case, human skin cells. When stem cells are placed in a conducive environment, they can develop into any organ.

But minibrains are still a far cry from a full human brain. To develop into a mature brain, these minibrains would need to communicate with other areas of a larger brain and have some sort of connection with the outside world. But this might not be far off. Already, scientists have given minibrains retinal cells so they can sense light.

While some note that these minibrains are nowhere near real human brains, others begin to feel uneasy at seeing this neural activity. What does it mean? In this quickly developing field, how soon will these minibrains develop even further? There is an ethical code when dealing with animals in the lab – should this code apply to minibrains too? Could they one day feel pain, have memories, or even become self-aware?

“There is now a need for clear guidelines for research,” says Dr. Nita Farahany and collaborators in a 2018 Letter to Nature. They point out that as research develops and these minibrains become more advanced, it is less far-fetched to believe that one day these minibrains might have some sort of sentience or feelings such as pleasure or pain. The benefits of minibrain research are promising, but they caution, “to ensure the success and social acceptance of this research long term, an ethical framework must be forged now, while brain surrogates remain in the early stages of development.”

Via Forbes