In a different thread you spoke of how if any Axons have "sprouted" post injury, it would speed up the recovery process after the surgeries you are testing. I am guessing this is the same for motor and sensory function? My question is, was this a theory before you started the trials or info stumbled upon during the trials? Ty Sifu Young!
Sprouting of axons is not a theory but an observation. In fact, what was originally claimed by Martin Schwab and others to be recovery due to axonal regeneration when Nogo was blocked turned out to be mostly due to sprouting. So, what is the difference between sprouting and regeneration?
Sprouting is the growth of new branches of axon that is already crossing the injury site. An axon that sprouts half a dozen branches will produce rapid improvements in sensory or motor function, often times within weeks. It is likely that most recover that occurs in incomplete spinal cord injury comes from sprouting.
Regeneration is the regrowth of an axon from the injury site back towards their original connection sites. Strictly speaking, the axon would not be considered to be "regenerated" unless it has reconnected with a neuron below the injury site. Before an axon has reconnected, the proper word to use is regrowing axon.
Axons can grow no faster than your hair and probably must slower, especially in the presence of axon growth inhibitors and absence of growth factors. We know that peripheral nerves will regrow after a crush injury. This regrowth often manifests itself in motor or sensory recovery many months later. In the spinal cord, depending on the injury level, regeneration may take years.
What I believe we are seeing in our trial now is regeneration. Long fiber tracts are regrowing long distances in the spinal cords and they appear to be making some synaptic connections with distal motor structures at 6-18 months after umbilical cord blood transplants. At least in initial stages, subjects are showing improved walking without much change in motor and sensory scores.
1 more, After regeneration has occurred and the Neuron has been connected. Do you find that the Neuron then branches out looking for new Neurons to regenerate even further?
Also I know these are walking trials designed to improve just that however I can't help thinking that one's hands would be the first to regenerate. I know you cannot divulge any info on the effectiveness of these trials but does that make any sense? Ty Sifu Young
Regeneration, however, takes much longer. More proximal segments, such as lower cervical segments in a person with a cervical spinal cord injury, should recover earlier than the legs. That is what I would expect as well. At the present, we are not seeing such recovery. It is true that we have had relatively few cervical spinal cord injury cases in our current study but I had hoped to see more and earlier recovery of voluntary hand function. Why not?
There are several possible answers. First, it may still be too early. We should wait a year or more before concluding there is no recovery. Some subjects are showing some recovery. Second, the arms and hands may require more direct innervation of the gray matter and have less programmed activity by structures such as the central pattern generator. Third, recovery of hand function may require intensive training as well.
We don't have answers to these questions. That is why doing trials is so important. We are learning from our experience.
- Goldberger ME (1974). Functional recovery after lesions of the nervous system. IV. Structural correlates of recovery in adult subjects. Recovery of function and collateral sprouting in cat spinal cord. Neurosci Res Program Bull 12: 235-9.
- Goldberger ME and Murray M (1974). Restitution of function and collateral sprouting in the cat spinal cord: The deafferented animal. J. Comp. Neurol. 158: 37-54.
- Murray M and Goldberger ME (1974). Restitution of function and collateral sprouting in the cat spinal cord: the partially hemisected animal. J. Comp. Neurol. 158: 19-36.
Last edited by Wise Young; 12-23-2012 at 06:11 AM.
Merry Christmas and a Happy New Year DR Wise Young.
Just wondering if everything was on track to submit the IND application by the end of this month, as previously stated/hoped....? Thanks!
I moved this post to its own topic in the Cure Forum: