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    grey matter-white matter regeneration

    Is it true or merely speculation that a person with a thoracic, or cervical injury, have a better result in axon regeneration? I guess my question is, do areas of grey matter propose a bigger challenge than say, the white matter? It seems we are close to axonal regeneration, but neuronal tissue in the grey matter, is this possible to restore?

    sherman brayton
    sherman brayton

    #2
    Gray matter regeneration (or replacement of neurons) requires white matter regeneration (axonal reconnection). It is indeed a greater challenge than white matter regeneration. It is one of the reasons why I feel that it is important that we do not close the door on stem cell research because it provides one of the few paths we currently have to explore to find ways to provide new cells to the spinal cord. Wise.

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      #3
      Reading things like this makes me wonder how people can think we'll be out of these chairs any time soon.

      "If the wind could blow my troubles away. I'd stand in front of a hurricane."
      "I QUESS THEY'LL HAVE TO RUN OUT OF RATS, BEFORE THEY TRY IT OUT IN HUMANS. WAKE ME UP WHEN IT'S OVER !!!"

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        #4
        Jeremy

        10% regeneration of white matter [ascending/descending tracts] in the spinal cord [the easier kind of regeneration] will restore significant function to us. It's not proving trivial by any means but is doable according to leading scientists. Unfortunately, we all expected to have promising therapies in trial for chronic injury by now. It's just going to take longer than we thought for complete chronic injury to get regenerative therapies. But it will happen.

        ~See you at the SCIWire-used-to-be-paralyzed Reunion ~
        ~See you at the CareCure-used-to-be-paralyzed Reunion ~

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          #5
          Jeremy, I think of it as this way. White matter (axons) must grow through the injury site both upwards and downwards. This is called regeneration (or axon growth). This is doable and will restore much function.

          But at the injury site there is also gray matter that has been damaged. I think of gray matter as the neuron bodies that branch off of and come into the spinal cord at that point. Those neuron bodies have been destroyed and if we expect full recovery, they must be replaced. That is why I believe stem cell research is so important - because Stem cells have the potential of being turned into neurons (gray matter).

          I am injured at t-12, and since the lumbar locomotor center is at L-1, there is a good chance my locomotor gray matter is injured. If it is, it will need to be replaced in order for me to walk again as the locomotor center seems to control walking. No matter where our injury is - even if axons (white matter) are made to grow through the injury site - there is going to be some portion of our body movements or functions that will not be fixed until the gray matter at the injury site is fixed. At t-12 or L-1, that function is most likely walking.

          This is my understanding. Dr. Young, please correct me if I am wrong. Bill

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            #6
            Actually I asked this before but STILL don't understand the answer. Maybe I'm really dense.

            Hypothetical injury at T4. All motorneurons at T12/L1 are fine... BUT they are connected to a "dead" part of the cord. (ie: below injury)

            If my axons start growing down from T4 ALL the way down, they are of no use unless they ALSO reconnect to the motorneurons along the way. And since these motorneurons are all still connected to the "dead & useless" cord below injury... wouldn't the new axons just grow right past their targets and be completely useless?

            I continue to don't get it.
            "Oh yeah life goes on
            Long after the thrill of livin is gone"

            John Cougar Mellencamp

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              #7
              Could someone please show me where they have ever shown how far they have ever gotten a regenerated axon to grow more than a few mm in a contusied spinal cord and work as a normal axon would and how many axons would they have to grow to get to the 10 percent level.

              "If the wind could blow my troubles away. I'd stand in front of a hurricane."
              "I QUESS THEY'LL HAVE TO RUN OUT OF RATS, BEFORE THEY TRY IT OUT IN HUMANS. WAKE ME UP WHEN IT'S OVER !!!"

              Comment


                #8
                mkowalski99, the only thing that is dead and useless below the injury site are axons that have died that descend or carry signals downward from the injury site. The entire cord is not useless below the injury site. For example, ascending axons from t-12/L1 and those that run through t-12/L1 and up are still intact up to the injury site and probably send sensory signals back to the injury site but not through it, depending on the axonal damage at the injury site.

                Since your injury is at t-4, your motor neurons at t-12/L1 should be fine and just waiting for axons to grow down the cord to reconnect with them. If that happens, you should be able to walk fine. But whatever function t-4 regulates, you may not get back until the gray matter there is repaired. And you probably will not feel anything in your legs until your sensory axons at the injury site grow upwards across the injury site and up to your brainstem.

                I may be in over my head. Would like to see Dr. Young's comments. Bill

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                  #9
                  Wise you lacked enthusiam for the 1 st time..........

                  I thought that cloning was in jeopardy in the US
                  but stem cell technology is still in infancy but growing so quickly. Are you referring to only ESC ??? I recently saw Dr. Kao and he examined my mri's from 95 todate (4 sets ). I am an incomplete T 2-5 and he says I have a cavity in the middle of the cord. I am guessing a bridge is needed composed of gray and white matter toclose the gap and hopefully connect someday.

                  Dr. Kao is a fine honest doctor and he didn't think I could benefit by surgery. He confirmed the cyst removed in Oct 98 by Dr. Green hasn't reappeared. And would only recommend surgery a compression occurs again and I worsen.

                  Wise, I can't tell you how many times over the last 3 years you have lifted my spirits!!!Thanks, Mike

                  Comment


                    #10
                    Now some of us wont need neurons replace if I understand the correlation of spasms to neurons. Because you don't have spasms in your muscles that have damaged neurons and a sign of intact neuron is having spasms in your muscles. Atleast this is my understanding please correct me if I'm wrong


                    LIVE IT UP AND LIVE IT LARGE!!!!
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                      #11
                      The vast majority of people with spinal cord injury have intact gray matter below the injury site. They should benefit from regeneration of axons that have been interrupted. The reason why I believe that regeneration will have beneficial effects is because we do not need to regrow the entire spinal cord. The spinal cord is very plastic and has the capability of making do with very few axons. Most people do not have transected spinal cords and have some axons that remain. Therefore, the goal of regeneration is to provide sufficient additional axons to cross the injury site and grow up or down the spinal cord to restore function.

                      Neuronal replacement is beginning to look feasible. Five years ago, I was not sure that we had any way of doing so. However, much evidence now suggests that the brain and the spinal cord is capable of adding new neurons and that adults have stem cells that are constantly producing new cells. Of course, they do not seem to be doing it sufficiently or fast enough to restore function and therefore adding some stem cells or boosting their activity may be the way to do this. Proof is not yet at hand that this is possible but I think that stem cell research is worth investing in. At the present, it is not clear whether adult stem cells can do the task as well as embryonic stem cells.

                      We should not be discouraged if, for example, the Diacrin trial does not show positive results at the phase 1 level. It is entirely possible that stem cell therapies *alone* will not restore function. We are very likely to need regeneration alongside stem cells to do the job. Obviously, if one is lacking the targets to which regenerated axons can connect to, the first thing to do must be to put the targets in. One way to do so is to place stem cells that can produce those targets.

                      What I believe the human fetal transplant (Gainesville) and the Diacrin fetal stem cell transplant trials are showing us is that it is safe to transplant such cells into the spinal cord. The human fetal transplant trial suggests that a short period of immunosuppression may be sufficient to prevent rejection of heterografts (cells from another individual). Both trials suggest that these cells will not grow out of control.

                      Wise.

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                        #12
                        I don't worry too much about gray matter in the cord. But what about the lower motor neurons where some of our muscles have atrophied? I understand that to make those areas work again we will need to implant neuronal stem cells. Is that correct? And because those neurons are lower motor, once a transplant is done will the peripheral nerve grow back to the cord or Dorsal (?) root? Wise?
                        Courage doesn't always roar. Sometimes courage is the quiet voice at the end of the day saying, "I will try again tomorrow."

                        Disclaimer: Answers, suggestions, and/or comments do not constitute medical advice expressed or implied and are based solely on my experiences as a SCI patient. Please consult your attending physician for medical advise and treatment. In the event of a medical emergency please call 911.

                        Comment


                          #13
                          Sue,

                          Motoneuronal axons should grow out the ventral roots of the spinal cord. The prevention of motoneuronal injury and replacement of motoneurons is of course the first priority of polio and amyotrophic lateral sclerosis research.

                          To date, nobody has yet demonstrated the replacement of motoneurons with neurons that subsequently grew their axons out of the spinal cord and reinnervated muscle. There are some attempts to do so now, not only in academic laboratories but also in companies. One of the most interesting approaches to doing this is at the University of Pennsylvania where they have discovered that it is possible to accelerate axonal growth by stretching the axons. Therefore, one intriguing possibility is to grow the motoneurons out of the body and use the axon stretching to get the axons to grow into a nerve, and then transplant the whole unit (motoneuron into the spinal cord and their axons into the muscle).

                          Wise.

                          Comment


                            #14
                            I never thought of stretching for this purpose. That's an interesting idea. I can easily imagine a lab full of post grads running it too. A full muscle to cord wiring kit in a bag--$595.75 [img]/forum/images/smilies/cool.gif[/img]

                            More seriously, I assume for ALS especially that the phrenic and cranial nerves of the lower chin that allow for speech and eating are the first motorneurons being worked on? And I will never be able to keep dorsal and ventral straight. Well, unless it's a fish. I had an aquarioum as a kid and remember dorsal fins... [img]/forum/images/smilies/biggrin.gif[/img]

                            [This message was edited by Sue Pendleton on Apr 22, 2002 at 12:39 PM.]
                            Courage doesn't always roar. Sometimes courage is the quiet voice at the end of the day saying, "I will try again tomorrow."

                            Disclaimer: Answers, suggestions, and/or comments do not constitute medical advice expressed or implied and are based solely on my experiences as a SCI patient. Please consult your attending physician for medical advise and treatment. In the event of a medical emergency please call 911.

                            Comment


                              #15
                              Sue, When we were quadripeds (as babies) our backs were dorsal and our fronts were ventral. For a long time, the medical literature used posterior and anterior (to distinguish us from animals, I presume) but that trend is changing and it has become okay to use dorsal and ventral in reference to the human.

                              ALS is one of the most frightening diseases that I know of. When the gene for ALS was discovered about 8 years ago, everybody thought that the cure was imminent. But, the only drug that has any effect on ALS is riluzole and it is not that effective. An old friend just wrote to me and told me that his wife has ALS. You can only pray that the progression of the disease does not eclipse the progress in research.

                              Wise.

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