Minuscule
blobs of human brain tissue have come a long way in the four years since scientists in Vienna discovered how to create them from stem cells.
A postmortem
analysis of human brain tissue, for example, conducted by Witelson and her colleagues at the Michael G. DeGroote School of Medicine at McMaster, revealed that women's neurons were 11 percent denser than men's in the prefrontal cortex and in a region of the temporal cortex that is involved with language processing, comprehension, and memory.
The result, says Flajolet, is a brain that is hard and transparent, almost «like glass,» which allowed the researchers to see the amyloid plaques in full detail and in 3D, in a full mouse brain hemisphere, as well as in small
blocks of human brain tissue.
Finally, the researchers analyzed
samples of human brain tissue from patients with Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis and multiple sclerosis.
In their comprehensive study, which involved a search of gene activity maps as well as
testing of human brain tissue, the researchers identified more than 100 enhancers which were much more active in the brain than in other tissues.
Transplanting the three - dimensional
clumps of human brain tissue into the brains of mice allows the organoids to continue to develop, sprouting life - sustaining blood vessels as well as new neuronal connections, the new study reports.
It appears to be involved, for instance, in the production of respiratory enzymes: it does not appear to be involved (and the would - be cybrid researchers have earnestly assured us that it is not involved) in the
production of human brain tissue.