Scientists have managed to keep tiny lab-grown brains alive for nearly six years, and these little brains have shown signs that they age just like our organic, naturally grown brains do.

The researchers, publishing their findings in Nature, dramatically extended the lifespan of brain organoids, which are clumps of brain tissue grown from stem cells that more or less mimic aspects of human brain development. The big breakthrough here is that most organoid experiments only last a few weeks to months. These were kept going for years, continuing to mature and all the while maintaining a cellular record of how old they were.

The researchers found that the organoid developed a lot of the same broad cell types seen in real brains. Using genetic and molecular measurements, they found evidence that the tissues followed the same developmental patterns going on in organic brain tissue. When researchers broke older organoids apart and rebuilt them into “chimeroids,” the cells kept evidence of their previous developmental age, sometimes skipping developmental steps they had already completed.

Freaky!

The Mini Brains Experience Age, So Are They Conscious?

The research could give scientists a better way to study the brain’s development and devastating neurodegenerative diseases like Alzheimer’s and Parkinson’s. There are some caveats. The organoids are not actual tiny human brains. They lack blood vessels, for one, and don’t have the same architecture and ability to perceive sensory information detected by the body.

In other words, they’re missing out on a lot of information processing. Then there’s a ton of ethical questions about consciousness that could spring up one day. If researchers create a conscious living brain in a lab, is it right to continue poking and prodding it?

According to the study’s senior author, Paola Arlotta, speaking with Scientific American, one of these things being even a little bit conscious is “highly, highly, highly unlikely.” Given the complexities of determining whether something is even conscious in the first place, it’s safe to say that this is a question that will be debated for a long time.

For now, just know that scientists have not created miniature thinking brains in a lab. It’s just a cluster of neurons that can remember its age… which isn’t less soothing to know.

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