Researchers are keeping pig brains alive outside the body

| | No comment yet

There was no evidence that the disembodied pig brains regained consciousness. However, in what Sestan termed a “mind-boggling” and “unexpected” result, billions of individual cells in the brains were found to be healthy and capable of normal activity.

“These brains may be damaged, but if the cells are alive, it’s a living organ,” says Steve Hyman, director of psychiatric research at the Broad Institute in Cambridge, Massachusetts, who was among those briefed on the work. “It’s at the extreme of technical know-how, but not that different from preserving a kidney.”

Read more

Mini brains: Artificially Created Tiny Brain “Organoids” Show Signs of Neural Activity

| | No comment yet

The “mini brains” were technically “cerebral organoids,” made from the cells that make up the region of the brain known as the cerebellum. They started out as clusters of stem cells raised in a special medium designed to support brain development, eventually growing into organoids with a similar structure as a real-life cerebellum.

Read more

Organoids, chimeras and ex vivo tissues

| | No comment yet

“Organoid” is the term generally used to refer to a small ball of human cells grown in cell culture from stem cells (human stem cells for human organoids). The stem cells may be embryonic stem cells, induced pluripotent stem cells, or other types of stem cells, but the effort has been to get cells that will all become one or more cell types found in an organ. Thus, there are human liver organoids, kidney organoids, gut organoids…and yes, brain organoids. The human neural organoids have been grown for over three years – and some of them have survived for over two years. They have diameters of about 4 millimeters (or a sixth of an inch), about the size of a very small pea. They have no vasculature and so the cells need to be in contact with the oxygen and nutrient bearing (and waste bearing-away) culture media. Currently human neural organoids have about two to six million neurons (no other brain cells so far, just neurons). They self-organize, grow synapses, fire, and continue to get more and more complex as time goes on. Still, by comparison, the human brain is estimated to contain approximately 86 billion neurons.

Chimeras – in this case, human/non-human brain chimeras – are creatures with some human brain cells and some non-human brain cells. (Thus far, in brains at least, they are always non-human animals with some human cells, not humans with some non-human cells.)  Chimeras have been used in research for many years, though organoids are opening new possibilities: such as transplanting human organoids into rodent brains – which turn out to grow blood vessels for them.

Researchers have also long used human brain tissue kept alive outside the body – ex vivo tissue – but what is used and how is, like chimeras, becoming “new and improved.” Instead of keeping flat sheets of human brain cells alive in a dish, researchers are keeping alive and studying larger and larger chunks of human brains, taken from neurosurgical discards or from the recently dead. There are even some efforts, so far only in non-humans, to keep whole brains from dead animals “alive” apart from their bodies.

Read more