grey matter-white matter regeneration

sbdspray · 04-18-2002, 01:46 PM

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

Wise Young · 04-19-2002, 04:27 AM

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.

Jeremy · 04-19-2002, 08:07 AM

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."

Jeff · 04-19-2002, 08:45 AM

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

~

bill j. · 04-19-2002, 12:36 PM

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

mk99 · 04-19-2002, 02:04 PM

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.

Jeremy · 04-19-2002, 02:07 PM

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."

bill j. · 04-19-2002, 02:54 PM

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

mikek · 04-19-2002, 02:56 PM

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

X-racer... · 04-19-2002, 03:02 PM

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!!!!

04-18-2002, 01:46 PM	#1
sbdspray Senior Member Join Date: Apr 2002 Location: katonah , ny, usa Posts: 494	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

04-19-2002, 08:45 AM	#4
Jeff Senior Member Join Date: Jul 2001 Location: North Brunswick, NJ, USA Posts: 6,858	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 ~

04-19-2002, 02:56 PM	#9
mikek Senior Member Join Date: Jul 2001 Location: Pompano Bch.,Fl. 33060 Posts: 474	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

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04-19-2002, 04:27 AM	#2
Wise Young Administrator Join Date: Jul 2001 Location: New Brunswick, NJ, USA Posts: 37,988	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.

04-19-2002, 08:07 AM	#3
Jeremy Senior Member Join Date: Jul 2001 Location: Canada Posts: 588	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."

04-19-2002, 12:36 PM	#5
bill j. Senior Member Join Date: Jul 2001 Location: Stratford, SD Posts: 6,820	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

04-19-2002, 02:04 PM	#6
mk99 Senior Member Join Date: Jul 2001 Location: toronto, canada Posts: 3,494	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.

04-19-2002, 02:07 PM	#7
Jeremy Senior Member Join Date: Jul 2001 Location: Canada Posts: 588	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."

04-19-2002, 02:54 PM	#8
bill j. Senior Member Join Date: Jul 2001 Location: Stratford, SD Posts: 6,820	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

04-19-2002, 03:02 PM	#10
X-racer... Senior Member Join Date: Jul 2001 Location: Eugene, OR Posts: 283	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!!!!