Scientists Gave Human Brain Cells to a Rat. Why?

Scientists transplanted human cerebral organoids ("minibrains") into rats, to better study brain disorders. The neurons grown in vivo looked more like mature human brain cells than those grown in vitro, and they made better models of Timothy syndrome. The human minibrains formed deep connections with the rat brains, received sensory information, and drove the rat's behavior.

Points of Clarification (Q&A based on common comments)
- Why didn't the rat reject the transplant, which frequently happens with organ transplants? /// They used immunocompromised (athymic) rats to avoid the problem of the immune system attacking the transplanted tissue.
- Was the licking behavior really due to optogenetics, or just seeing the blue light? /// A separate group of rats (control group), with a transplant but no optogenetics, also completed the red/blue light water training. They showed no significant difference in licking behavior during red and blue light. This suggests that the differences were really due to optogenetic stimulation of the organoid (not, for example, seeing the light). You can see how the control group did, compared to the optogenetic transplant group, in Figure 5j of the study, link below.

[derek]

"Last I remember, I was about to crash my car. When I woke up, I was a rat."

[bitcoinzoomer]

Finally, manmade horrors within my comprehension

[Emperor-Quill]

Bartholomouse: "What's wrong with Ratthew?"

HoRATio: "Not sure, the human took him somewhere and ever since he's been muttering about some cruel god named "taxes"

[NicolasCermak]

Imagine the rat starts squeaking morse code for "They'll never believe you"

[denissmith]

-What are we going to do tonight, Brain?
-The same thing we do every night, Pinky. Try to take over the world.

[qawamity]

Call me crazy if you like, but it seems to me that the human tissue in the rat did not control the rat at all. It was integrated into the rat brain. It's like adding a a video capture card to your PC, it doesn't control the computer, it becomes part of it and augments its capabilities. The experiments with blue light demonstrate this integration.

[horsepowermultimedia]

Those scientists are trying to recreate Ratatouille. 💀

[mzzar]

they should do a test to see if rats with human cells are better at solving puzzles than a normal rat.

[SWISS-]

Ah so this is how Remy was born in ratatouille. They placed human neurons into the sensory area of the Rats brain, so that's why he REALLY loved food lol

[heypankajhere]

Legend says this mouse went underground with his 4 turtle apprentices.

[rockercas]

if you give human brain cells to a rat, he will ask for a glass of milk

[bananajoe]

At first I was worried, then they started talking about using rabies. Now I'm terrified.

[kalliaslands]

In case anyone was wondering this has actually been done in a human. A patient with Parkinson’s had a cell sample taken which was then cultured into dopanergic neurons. The ethics review then gave special permission for the patient to undergo experimental surgery in which these neurons were inserted into his motor cortex. The procedure appeared to lead to a halt in the progression of his Parkinson’s disease but it is hard to tell until this is being tested on a dozens of subjects

[Hhh-jo]

These scientists need to chill out.

The last time this was succesfully attempted, they created Jerma.

[thaedleinad]

"Dollar store in vitro organoids"

Ok, I am taking this one as a song title to my new single.

[HolyApplebutter]

"When I understood the weakness of my flesh, it disgusted me. I craved the strength and certainty of other flesh."

[PeppermintSwirl]

If we’re not careful, we are gonna have rats who ask “to squeak, or not to squeak?”

[gneu]

Imagine how bro must feel being conscious as a rat

[xSephironx]

"To make it more human, we attach it to rats..."

Ah yes very human

[yourgenerickid]

A rat? I was a rat once. They locked me in a room. A rubber room. A rubber room with scientists. And scientists made me into a rat.