Researchers have made a breakthrough in stem cell research, which could lead to an improved understanding of motor neuron diseases. A team of scientists from the Universities of Cambridge, Cardiff and Edinburgh has developed an innovative way of producing motor neurons from stem cells.

Motor neurons are cells which travel between the nervous system and the muscles, sending messages from the brain to the body. They give us conscious control of our musculature, allowing movements like walking, speaking and breathing. The neurons are affected in a group of rare neurological disorders known as motor neuron diseases.

The researchers have developed a new technique for producing motor neurons from embryonic stems cells, primitive cells which have not yet differentiated into a specific type of cell. Stem cells can divide indefinitely, replenishing their supply, which makes them valuable research tools. Gathering the cells involves the destruction of fertilised embryos; hence the ethical controversies that surround their use.

Although scientists have been able to create motor neurons from stem cells in the past, they could only generate one kind of motor neuron. The new process allows a range of motor neurons to be produced. This is crucial because it will pave the way for experiments which may explain why motor neuron diseases affect some types of motor neuron more than others.

Dr Rickie Patani, a neuroscientist from the University of Cambridge, said: "Although motor neurons are often considered as a single group, they represent a diverse collection of neuronal subtypes. The ability to create a range of different motor neurons is a key step in understanding the basis of selective subtype vulnerability in conditions such as motor neuron disease and spinal muscular atrophy."

Motor neuron diseases are devastating degenerative conditions in which voluntary muscle function is lost, leading to gradual paralysis and loss of the ability to speak, breath and swallow. They are eventually fatal.

Cambridge’s most famous motor neuron disease sufferer is acclaimed theoretical physicist and previous Lucasian Professor of Mathematics, Stephen Hawking. He was diagnosed at Oxford, after noticing that he had become clumsy and sometimes fell over. He has written, “Before my condition had been diagnosed, I had been very bored with life. There had not seemed to be anything worth doing. But shortly after I came out of hospital, I dreamt that I was going to be executed. I suddenly realised that there were a lot of worthwhile things I could do if I were reprieved.”

Hawking has survived more than forty years with the disease, despite half of sufferers dying within fourteen months of diagnosis. He is now almost completely paralysed, and communicates by controlling a speech synthesiser via a muscle in his cheek.

The research was published in Nature Communications on Tuesday.