Brain waves were detected from "mini-brains" developed in the laboratory

For the first time, brain tissue developed in a laboratory spontaneously exhibited electrical activity, which is surprisingly similar to the activity of the human brain. Specifically, it looks like the brain activity of premature babies.

This is a huge discovery that opens up opportunities for studying the early development of brain disorders.

Some scientists have also hesitated.

These lab-grown brains are called organoids – three-dimensional, simplified, and simplified versions of lab-grown organs for research purposes, such as testing drug reactions or developing cells under certain adverse conditions.

The research was first presented at a conference in November 2018 and has now been peer reviewed and published in Cell strain cell.

"The level of neural activity we observe is unprecedented in vitro," says neuroscientist Alysson Muotri of the University of California at San Diego.

"We are getting closer to a model that can actually generate these early stages of a sophisticated neural network."

Muotri has been developing brain organelles in his lab for a few years, but this is the first time that his team and himself have seen anything like human brain activity.

The organoids in question were developed from human pluripotent stem cells or stem cells that could become any other type of cell. They brought these "whites" to develop into cells that make up the cerebral cortex, the area of ​​the brain responsible for really important things like memory, perception, cognition, thought, and sensory processing.

You can see a cross section of one of the organoids below.

(Muotri Lab / UCTV)

Hundreds of these tiny brains were grown over a 10-month period, with tests to ensure that the right genes for brain development were expressed. They also continuously monitored organs with electroencephalography (EEG).

At six months, Nature According to reports, the brainlets were showing a very energetic brain activity – much more than anything the team had noticed before.

At analysis, the activity did not look much like the organized and predictable brain activity of an adult. But it looked like a different kind of brain activity. It had common features with the chaotic outbreaks of synchronized brain activity seen in premature infants.

"While the activity of organoids on the network does not present all the temporal complexity observed in the adult, the pattern of alternating synchronized rest and event periods on the network is similar to the electrophysiological signatures present in the EEG of the preterm newborn, "the researchers wrote.

It was not exactly the same. But a machine learning model formed on premature EEG signatures could identify many common features with a normal development timeline. In the past 28 weeks, organelles appeared to be following a similar developmental trajectory as a premature baby of the same age.

Brain organelles do not really look like parts of the human brain. Not only are they reduced and simplified, but they do not have other areas of the brain to connect to. They have also been designed to be deficient in a protein essential to the normal functioning of neurons.

But they could represent a step towards a better understanding of brain development, since the brain of premature babies is not easy to find and that the brain of adults is notoriously complicated.

"Although we did not claim functional equivalence between organoids and a complete neonatal cortex," the researchers write, "the current results represent the first step towards an in vitro model that captures some of the oscillatory dynamics spatio -Temporal complexes of the human brain ".

Researchers will continue to try to develop brainlets to see if they continue to mature.

But others are really concerned about the proximity of developing a conscience in a culture tank in a laboratory. Until now, no brain shows any sign of consciousness, but as experience continues, this could be a possibility.

"The closer they come to preterm, the more they should worry," said neuroscientist Christof Koch of the Allen Institute for Brain Science in Seattle. Nature in November 2018, when the research was presented to.

Given the careful engineering of organoids to inhibit normal function, researchers are not worried at this stage. However, if they start showing signs of consciousness, they will consider ending the project.

The search was published in Cell strain cell.

This article has been updated from our cover of the pre-printed presentation of this work in November 2018.