Animal stem cell experiments:
We continue to focus on generating motor neurons from embryonic stem cells, and have recently shown that we can generate thousands of new motor neurons in the spinal cords of paralyzed animals. Further, at Johns Hopkins, we have learned how to stimulate these motor neurons to extend axons out toward muscle.
A critical goal of restorative therapies is to rewire the nervous system. Specifically, motor neurons must extend their axons (“wires”) to connect to muscle. We must learn how to appropriately direct these axons in order to generate functional recovery. We have not yet defined the biological principles that guide all of these areas.
This will be the focus of the next three years. It is unclear how quickly these findings will be applied to paralyzed patients. In the current environment, a significant proportion of stem cell research is not allowed and funded by the federal government.
Clinical trials in neurorestoration:
The spinal cord is not “programmed” to regenerate after injury. It is an evolutionary trade-off that we have very complex neural systems, yet unlike lower animals, we cannot recover function after injury.
The first step is to develop a strategy to “reprogram” the nervous system so that it can regenerate and define how to generate spinal motoneurons from embryonic stem cells. This will enable transplantation studies in animals which will further enable the development of clinical trials for these neurorestorative therapies in humans.
We are unsure when clinical trials with neurorestorative therapies will commence.