Stem cells with Neanderthal genes developed into mini-brains

Neanderthal 'mini-brains' have been successfully grown in a dish by a team from the University of California, San Diego (UCSD).

Presenting at the UCSD conference, Imagination and Human Origins, Dr Alysson Muotri, a geneticist at UCSD School of Medicine, shared how his lab grew brain organoids from stem cells containing a Neanderthal version of a key gene required for normal brain development: NOVA1.

'We're trying to recreate Neanderthal minds,' Dr Muotri told Science magazine.

The team at UCSD created the organoids through a lengthy process starting with skin cells donated by neurotypical individuals. These cells were first reprogrammed to become pluripotent stem cells, capable of becoming any cell type in the body. Then their NOVA1 gene was edited using CRISPR/Cas9, to produce the Neanderthal version of the gene.

The stem cells containing the Neanderthal NOVA1 were then grown in a dish for several months to produce mini-brains, and these were compared to mini-brains grown from stem cells containing the unedited, human NOVA1. 

While the research is not yet published, the team says they have already noticed differences. The Neanderthal brains make fewer synaptic connections than their human counterparts, and certain cell types migrate more quickly. 

These differences result in an atypical neural network, and Dr Muotri noted that this pattern of differences mirrors what his lab had previously found in the neural development of children with autism.

'I don't want families to conclude that I'm comparing autistic kids to Neanderthals, but it's an important observation,' Dr Muotri, who has a step-son with autism, told Science. 'In modern humans, these types of changes are linked to defects in brain development that are needed for socialisation. If we believe that's one of our advantages over Neanderthals, it's relevant.'