The brain in a vat is a classic philosophical thought experiment, but now an actual vat has been used to grow actual brains. Well, tiny, tiny brainlets, grown out of stem cells.
Dr Madeline Lancaster and her colleagues from the Institute of Molecular Biotechnology at the Austrian Academy of Sciences grew embryonic stem cells into what they called “cerebral organoids”, in a gel-like substance under conditions similar to the human womb (Lancaster MA, Renner M, Martin C-A, Wenzel D, Bicknell LS, Hurles ME, Homfray T, Penninger JM, Jackson AP & Knoblich JA 2013, “Cerebral organoids model human brain development and microcephaly”, Nature, doi:10.1038/nature12517).
The miniature brains, each about 3-4 mm in diameter, developed simple cerebral cortices, retinas and other kinds of brain tissue.
Of course, it’s not really an attempt to create disembodied consciousness, but rather models to help understand brain functions and disorders. The team has previously made models of other organs, like eyes, pituitary glands and livers, but these were the first brains.
To demonstrate how this can help understand disorders, some of the organoids were made from cells from a patient with microcephaly. As you’d expect, those brains turned out smaller, but in the process they revealed why: the stem cells seemed to differentiate earlier, before they could grow in volume.
So this miniscule grey matter, although not able to think, has already taught us something.
And next time someone tells you to grow a brain, you’ll know how to do it.
(This story first aired on 12 September 2013 – you can listen to the podcast.)