Scientists have been growing tiny "brain organoids" in a petri dish for years, at least as far back as 2011.
Why? They hoped to study these tiny brains and better understand how our own brains work.
The "mini-brains" have been used to create models of the brain and study the causes and effects of Alzheimer's, Parkison's, and other neurological diseases.
It's impossible to directly study a functioning human brain. We have MRIs. We can attach electrodes to people's skulls. But we can't dissect a functioning brain without, well, destroying its function and killing the person who was using it.
But if scientists grow stem cells into neural tissue and nurture it to form a "brain organoid," then they can poke, prod, and cut up the little guy as much as they please.
Alas, the specks of brain tissue in the petri dish aren't nearly as complex as human brains. They don't form synpases, or connections between neurons, like our brains have.
So, some scientists decided to implant some adorable brain organoids into the brain tissue of living mice to see if they would begin growing into and with the mice's brains.
After a few failed attempts to implant in adult rats, researchers managed to implant the organoids into infant mice.
The infant mouse's brain is still forming synaptic connections, so the organoid "mini-brain" was able to form its own synaptic connections like the roots of one plant intertwining with the roots of another.
Scientists hope to use these Frankenstein hybrids of mouse brains and lab-grown humanoid brains to create more realistic models of the human brain and better understand how various disorders affect it.
Of course, ethical guidelines will be created to govern how researchers use the "mini-brains." Don't expect any "mini-brain" implants in human infants to correct genetic neurological disorders any time soon.