Metro Science: Mice are getting mini human brains, your brain on booze, and transplant talk
A series of scientific breakthroughs has led to this moment: Disney's Ratatouille (almost) became real.
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The human brain is a bit of a black box. Researchers can get a peek with an MRI or biopsy, but they can’t look at brain tissue directly until you're dead.
As for science's trusty human stand-in, mice and rats? Their brains are not that similar to us super-smart homo sapiens.
Now scientists are closer than ever to a solution: Making tiny, living models of human brains and putting them in mice.
The starting materials: It starts with special cells called induced pluripotent stem cells. They're made by exposing regular adult cells to proteins called transcription factors, which switch specific genes on or off. This transforms cells from their specialized state back into blob-like stem cells that can develop into almost anything, from blood to skin to brain.
Making a mini-brain: In 2013, scientists put induced pluripotent stem cells into a machine called a bioreactor and spun them around in a bath of specially selected nutrients and proteins until they turned into brain cells. Amazingly, these cells self-assembled into complex, multi-part, functional structures similar to embryonic human brains. These lentil-sized mini-brains are called cerebral organoids.
Into the mind of a mouse: Then, in 2017, a bombshell. Several different groups of scientists implanted human mini-brains into mice and rats. And it worked. In mice, they connected to the animals' blood supply and grew new neurons. Human brain bits implanted in rats' vision control centre sparked when light was shone in their eyes.
Science story: Bad brain brew
"Don't drink so much, you're pickling your brain."
It turns out that well-worn advice may be true. According to a new study in Stem Cell Reports, in mice, drinking alcohol kills stem cells that live in the brain. Those cells (in people and mice alike) are important for healing and maintaining thinking and memory as we age.
SOUND SMART: Your science vocabulary word of the week: ALLOGRAFT
Definition: An allograft is a cell, tissue or organ transplant from a different member of your own species.
Use it in a sentence: The newlyweds looked so in sync, I almost congratulated them on their mutual heart allograft.
WATCH: Metro's Citizen Scientist, Genna Buck, delves into the scientific and ethical implications of putting human brains into rodents. Watch live on facebook.com/metrocanada on Friday at 12 p.m. EST