Cells in the motor cortex – the brain area responsible for movement control – and sensory cells were both examined. Scientists found that each worked equally well. In fact, scientists discovered that two-thirds of the neurons could be used to trigger muscle movement. Moritz claims that the researchers found nearly every tested neuron in the brain could be used to control this form of stimulation. The study team also discovered monkeys could learn to quickly control newly isolated neurons in order to control their muscles.
Prior studies in this area have dealt with using computers and other devices to transmit brain activity into a prosthetic arm. Moritz adds that the key strategy is to use actual muscles of intact limbs instead of artificial robotic arms or other devices that can be controlled, but have limited practicality.
The researchers claim they have a long term goal of helping paralyzed humans regain the ability to eat and drink unassisted. Currently they are working on an implantable wireless computer interface device to achieve this goal. However, the final result of this work is still potentially years, or even decades, away before it’s ready for human trials.
On the stem cell front of paralysis treatment, a UC Irvine study is the first to show that human neural stem cells can restore mobility in specific cases of spinal cord injury. The implications behind this study suggest a prospect of treating a broader population of patients.
The UCI study is important because the therapy shows restoration of mobility during the later chronic phase – the period following spinal cord injury where inflammation has stabilized and recover has reached a plateau. No drug treatments exist to restore function in these cases.
The research team transplanted human neural stem cells into mice 30 days following a spinal cord injury resulting in hind-limb paralysis. The cells then differentiated into neural tissue cells, such as early neurons and oligodendrocytes, and travelled to the sites of spinal cord injury. Three months following the initial treatment, the mice showed a significant and ongoing recovery of walking ability in two separate tests of motor function when compared with control groups.
Aileen Anderson, an associate professor of physical medicine and rehabilitation at UCI, claims that using human neural stem cells is a novel therapeutic approach that has great potential for treating spinal cord injury. She believes this study builds on preexisting work published in the acute phase of injury and will offer additional hope for those who are paralyzed or suffer from impaired motor function.