May 6 - Shining pulses of blue light on exposed nerves can restore movement in paralysed limbs, according to scientists in the UK. They say their experiments on paralysed mice could eventually lead to an effective therapy for people with motor neuron disease and spinal cord injuries. Jim Drury has more.
Small blue LED lights could hold the key to treating motor neuron disease, a devastating condition that causes muscle paralyses and often, death in its victims. Researchers in Britain are using the flashing lights to artificially control the leg muscles of paralysed mice. The light stimulates specially engineered neurons implanted in the animals' exposed nerves, triggering a connection between the nerve and the muscle The motor neurons were created from stem cells by Kings College University biologist Dr Ivo Lieberam and transplanted into injured nerve branches. Lieberam says each cell contained a light sensitive gene taken from marine algae. SOUNDBITE (English) IVO LIEBERAM, KINGS COLLEGE LONDON, SAYING: "If you take that gene out of context and build it into almost any other type of cell, including human or mouse neurons, you can make these neurons artificially sensitive to light and that allows you basically to build a little pacemaker computer, which has an LED built into it so it can produce light flashes and then impose these light flashes onto the neurons." Dr Barney Bryson from University College London, then shone blue light onto the exposed nerves in the paralysed leg muscles of the anaesthetised mice. SOUNDBITE (English) BARNEY BRYSON, FIRST AUTHOR, AND POST DOCTORAL ASSISTANT RESPONSIBLE FOR IN VIVO EXPERIMENTS, UNIVERSITY COLLEGE LONDON (UCL), SAYING: "Just an LED light emitting blue light onto the nerve which activates the axons or the processes that come from the motor neurons and contact the muscle fibres…. just by varying the frequency of the flashes we're able to adjust the intensity of the muscle contraction." Bryson now plans to attach miniature fibre-optic cuff illuminators to damaged mouse nerves to stimulate the transplanted neurons without having to expose the nerve and restore motor function for longer periods of time. Study co-author, UCL, Professor Linda Greensmith, says the technique causes fewer side effects than therapies currently being used on motor neuron patients, which use electricity to stimulate nerves. SOUNDBITE (English) PROFESSOR LINDA GREENSMITH, UNIVERSITY COLLEGE LONDON (UCL) LEAD AUTHOR, SAYING: "With electrical stimulation you can also stimulate the pain fibres, making it very uncomfortable for MND patients to cope with. In addition, the advantage of this method is that it stimulates the muscle in the appropriate way, so that it doesn't become too fatigued, which is one of the problems when you stimulate with electrical stimulation." The team hopes within five years to have developed an optical pacemaker which could allow motor neuron disease and spinal injury patients to walk and even breathe on their own, overcoming muscle paralysis with the power of light.