A gene therapy experiment in mice raises hopes that, one day, scientists will be able to offer hope to motor neurone disease patients.
The gene therapy could one day help human patients
Scientists at Johns Hopkins University in Baltimore, US, are now starting to recruit patients for trials in humans - hopefully starting in a year's time.
The mice were engineered so that they would develop a similar condition to a form of motor neurone disease called amyotrophic lateral sclerosis (ALS).
This is the most common form of the disease, found in nine out of ten motor neurone patients.
Nerves controlling the muscles gradually die, leading eventually to paralysis and death.
The idea behind the gene therapy is to introduce a gene which would lead to the production of a chemical called insulin-like growth factor-1.
The chemical appears to be able to protect the nerves, and prevent them from dying.
The research was detailed in the journal Science.
Scientists use a virus - in this case a cold virus - to "infect" the nerve cells and bring in the new gene.
The specially-engineered mice, because they have a much shorter lifespans than humans, also developed the disease more quickly, suffering first symptoms at 90 days old, and dying on average within 45 days.
The gene therapy was injected into key muscles in the legs and upper chest.
Mice that got the therapy at 60 days old developed symptom on average a month after those who were untreated - and lived on average 40 days longer.
The treated mouse that lived the longest managed to survive for 265 days, compared to 140 days for the longest-lived untreated mouse.
Once the symptoms had emerged at 90 days, injections extended life by 22 days on average.
Professor Jeffrey Rothstein, one of the Johns Hopkins researchers, said: "We're very excited about this.
"Even in mice, progression of the disease is so rapid that we only test possible treatments before the mice get sick - it is amazing that this gene therapy can slow progression even after symptoms develop."
Dr Fred Gage, from Salk Institute in California, which contributed to the study, said: "I am proud and excited that this investigation may result in the first ever effective therapy for ALS.
"We've done it in the mice, now let's forge ahead aggressively and responsibly, and try it on people."
News of the trial was greeted with great interest in the UK as well.
A spokesman for the Motor Neurone Disease Association told BBC News Online: "This is potentially a very important study.
"With the chequered history of gene therapy in clinical trials, we have to approach patient studies with a degree of caution, but it is heartening to know that the researchers are already making plans to take this work out of the lab and into the clinic."
Johns Hopkins is advertising for patients to take part in the first human clinical trial, described as "about a year" from starting.
The research unit can be contacted on +001 4109558511.