[amphitoky]

they tend to be from donated skin cells, in fact, which are reprogrammed to produce brain tissues. see for example https://www.nature.com/articles/nprot.2014.158

[eadmund]

Donated by the human whose cells those were, by someone else?

That Nature article seems to discuss both approaches, using both induced pluripotent stem cells and embryonic stem cells — which of course are not donated by the human being which they once were part of.

[finalspark]

We only use IPSC. Details of the protocol to turn them into neurons and glial cells are described in our publication. https://www.frontiersin.org/journals/artificial-intelligence...