The human brain contains about 100,000,000,000 neurons (that’s 100 billion).

It also contains more than 10 times that number of other types of cells, called glial [glee-ul] cells. Glial cells support the neurons and help them to do their job, which is firing electrical signals so that we can move, think and remember.

There’s a lot that scientists don’t know about the brain, and tackling this complexity is daunting. We can use ‘animal models’ with simpler nervous systems, such as the zebrafish, or we can examine human brain tissue that has been donated after death. But best of all is to study living human neurons.

The promise of stem cells

Fortunately, stem cell technology, which we have pioneered with a handful of other labs worldwide in the last few years, can help.

Using stem cells, we can grow motor neurons ‘in a dish’ in the lab – ready and available for experiments. To do this, we first take a skin biopsy from a volunteer donor and harvest the skin cells. We keep the cells alive in a plastic dish filled with a nutrient-rich liquid that is kept in an incubator at body temperature. We then convert the skin cells, by a series of ‘chemical cookery’ steps, into stem cells. The stem cells will grow and replicate themselves, providing an abundance of cells for our scientists to work with. Finally, through more ‘chemical cookery’ over a period of a few months, the stem cells are converted into motor neurons.

The living neurons look and behave just as brain cells would.

What makes this technology even more useful is that we can compare dishes that contain cells from people with or without MND. Excitingly, we have found some differences in how the cells behave in certain conditions.

We’re now working out what those differences are, so that we can start testing drugs on them. If we find a drug that slows neurodegeneration in MND cells, it could be used in a clinical trial in years to come.

Meet the researchers

PhD student Owen James explains how he uses stem cells in his research on a mutation that affects MND.

Related links

News (February 2018): Stem cell research reveals differences in cells from people with MND

MND: How could stem cells help? Factsheet on the EuroStemCell website

Project description for academics: Modelling MND using human induced pluripotent stem cells