Neural Darwinism and the development of ADHD

[Peripheral]

Scientific Evidence Based,

opinions/ideas,

would be greatly appreciated.




Neural Darwinism

The Dynamic process by which 90 percent of the human brain's circuitry is wired after birth has been called "neural Darwinism" because it involves the selection of those nerve cells(neurons),

synapses and circuits that help the brain adapt to its particular environment,

and the discarding of others.

In the early stages of life,

the infants brain has many more neurons and connections than necessary--billions of neurons in excess of what will eventually be required.

This overgrown,

chaotic synaptic tangle needs to be trimmed to shape the brain into an organ that can govern action,

thought,

learning and relationships and carry out its multiple and varied other tasks--and coordinate them all in our best interests.

Which connections survive depends largely on input from the environment.

Connections and circuits used frequently are strengthened,

while unused ones are pruned out:

indeed,

scientists call this aspect of neural Darwinism synaptic pruning.

"Both neurons and neural connections compete to survive and grow,"

write two researchers.

"Experience causes some neurons and synapses (and not others) to survive and grow."

Through this weeding out of unutilized cells and synapses,

the selection of useful connections and the formation of new ones,

the specialized circuits of the maturing human brain emerge.

The process is highly specific to each individual person--so much so that not even the brains of identical twins have the same nerve branching,

not even the brains of identical twins have the same nerve branching,

connections and circuitry.

In large part,

an infant's early years define how well her brain structures will develop and how the neurological networks that control human behaviour will mature.

"Developmental experiences determine the organizational and functional status of the mature brain,"

writes child psychiatrist and researcher Bruce Perry.

Or in the words of Dr.Robert Post,

chief of the Biological Psychiatry Branch of the [U.S.] National Institute of Mental Health:

"At any point in this process you have all these potentials for either good or bad stimulation to get in there and set the microstructure of the brain."

And it is precisely here where the problem arises for young children who will,

in adolescene and beyond,

become chronically hooked on hard drugs:

to much of what Dr. Post called bad stimulation.

This is true of the hardcore intravenous drug users such as the ones I deal with in the Downtown Eastside.

In many other cases it's not a question of "bad stimulation" but a lack of sufficient "good stimulation".

Our Genetic capacity for brain development can find its full expression only if the circumstances are favorable.

To illustrate this,

just imagine a baby who was cared for in every way but kept in a dark room.

After a year of such sensory deprivation the brain of this infant would not be comparable to those of others,

no matter what his inherited potential.

Despite perfectly good eyes at birth,

without the stimulation of light waves,

the thirty or so neurological units that together make up our visual sense would not develop.

The neural components of vision already present at birth would atrophy and become useless if this child did not see light for about five years.

Why?

Neural Darwinism.

Without the requisite stimulation during the critical period allotted by Nature for the visual system's development,

the child's brain would never have received the information that being able to see is needed for survival.

Irreversible blindness would result..

What is true for vision is also true for the dopamine circuits of incentive-motivation and the opioid circuitry of attachment-reward,

as well as for the regulatory centers in the prefrontal cortex,

such as the orbitofrontal cortex--in others words,

for all the major brain systems implicated in addiction that we surveyed in the the three previous chapters.

In the case of these circuits,

which process emotions and govern behaviour,

it is the emotional environment that is decisive.

By far the dominant aspect of this environment is the role of the nurturing adults in the child's life,

especially in the early years.

All quotes from the book for "In The Realm Of Hungry Ghosts", pages 183-184

written by Gabor Mate, M.D.

[pechemignonne]

I agree with the information, but I chose Disagree in the poll because I disagree with your obvious conjecture that this relates to the genesis of ADHD.

Sure, deprivation can cause similar symptoms to ADHD. We know this. The symptoms are different in ways that are recognizable to experts, though, and they stem from a different cause.

Deprivation does not cause ADHD. ADHD occurs most often because of genetic heredity, and secondly because of organic chemical or tissue damage. Just because Neural Darwinism exists, does not make it the cause of any and every disorder.

Neural Darwinism does not cause deafness, for example. Deafness is either inherited or caused by some traumatic injury. ADHD, as far as is presently known, is the same.

It doesn't matter how many threads you create, the facts remain the same.

[ginniebean]

Originally Posted by Geronimoo Back-Y-Rita

Scientific Evidence Based,

opinions/ideas,

would be greatly appreciated.

Geronimo, there is information in your post, it's in the form of a quote. However, there is no evidence in the post. How can you agree or disagree without evidence?

I'd need to know what are the competing theories, and what are the evidence for each to know which is more sound and which is less so.

[pooka]

Interesting idea, but I'm not quite sure how you're applying this to ADHD. Are you suggesting that the lack of executive functions defined as ADHD is caused by ADHD children not using executive functions in their developmental years as much as their NT counterparts do? I'm not convinced that that makes much sense. If this is what you're saying, then it becomes a chicken-or-the-egg situation: did the disuse of executive functions cause the ADHD, or did the ADHD cause the disuse of executive functions? And how can one or the other ever be proven?

[Peripheral]

Originally Posted by ginniebean

Geronimo, there is information in your post, it's in the form of a quote. However, there is no evidence in the post. How can you agree or disagree without evidence?

I'd need to know what are the competing theories, and what are the evidence for each to know which is more sound and which is less so.

Thanks,

Good point,

I'm learning,

I guess I should ask you what you disagree with because I can feel I can prove the information else where.

Ginnie , if you could get rid of the poll that would be great!

So what information do people want evidence for?

I have looked into the information an feel it is all true.

[ginniebean]

I can't get rid of the poll I don't mod this section.

I don't 'disagree or agree'. It's interesting but I in order for me to agree or disagree I'd need to see the science.

[KronarTheBlack]

Neural Darwinism, a large scale theory of brain function by Gerald Edelman, was initially published in 1978, in a book called The Mindful Brain (MIT Press). It was extended and published in the 1989 book Neural Darwinism – The Theory of Neuronal Group Selection.

Edelman won the Nobel Prize in 1972 for his work in immunology showing how the population of lymphocytes capable of binding to a foreign antigen is increased by differential clonal multiplication following antigen discovery. Essentially, this proved that the human body is capable of creating complex adaptive systems as a result of local events with feedback. Edelman's interest in selective systems expanded into the fields of neurobiology and neurophysiology, and in Neural Darwinism, Edelman puts forth a theory called "neuronal group selection". It contains three major parts:

1 Anatomical connectivity in the brain occurs via selective mechanochemical events that take place epigenetically during development. This creates a diverse primary repertoire by differential reproduction.

2 Once structural diversity is established anatomically, a second selective process occurs during postnatal behavioral experience through epigenetic modifications in the strength of synaptic connections between neuronal groups. This creates a diverse secondary repertoire by differential amplification.

3 Reentrant signaling between neuronal groups allows for spatiotemporal continuity in response to real-world interactions.

I agree with the opinion you have posted but do not see where you are going with it? What is the point of you posting this? Its informative but I think we need to see what you want from the post?

However the theory has changed somewhat or should be changing because what happens before birth is more epigenetically important than what happens after birth.

[Peripheral]

Hi,Pechemignonne

I appreciate your help.

I am trying to explore this issue in a science based manner.

I'm not sure what parts of your reply are evidence based .

All I'm asking is that you prove me wrong, with evidense.

I will post a question.

Originally Posted by pechemignonne

I agree with the information, but I chose Disagree in the poll because I disagree with your obvious conjecture that this relates to the genesis of ADHD.

Sure, deprivation can cause similar symptoms to ADHD. We know this. The symptoms are different in ways that are recognizable to experts, though, and they stem from a different cause.

Deprivation does not cause ADHD. ADHD occurs most often because of genetic heredity, and secondly because of organic chemical or tissue damage. Just because Neural Darwinism exists, does not make it the cause of any and every disorder.

Neural Darwinism does not cause deafness, for example. Deafness is either inherited or caused by some traumatic injury. ADHD, as far as is presently known, is the same.

It doesn't matter how many threads you create, the facts remain the same.

Pechemignonne,

[Peripheral]

Originally Posted by ginniebean

I can't get rid of the poll I don't mod this section.

I don't 'disagree or agree'. It's interesting but I in order for me to agree or disagree I'd need to see the science.

No big deal about the poll , sorry.

[KronarTheBlack]

watch this video from BBC on this topic.

http://topdocumentaryfilms.com/the-n...that-made-you/

Very interesting. I just download all Horizon documentaries. I have every single one since 1990.

[Peripheral]

Originally Posted by KronarTheBlack

watch this video from BBC on this topic.

http://topdocumentaryfilms.com/the-n...that-made-you/

Very interesting. I just download all Horizon documentaries. I have every single one since 1990.

KronarTheBlack,

Thanks for your input.

I am not giving up.

I just need to figure this out.

I haven't been in school for a long time.

I don't understand what I am suppose to provide.




I don't understand what input I am suppose to put into Dr.Mates Points.

How do I say what I think see is saying,

Thats why I typed the pages out.

To have his input,

I can't disprove the information?




I will tell you what I think but that is not evidence,

And I really like your post.

What classifies as evidence.

There is lots of articles but they are just opinions to.


I think he is saying how, neurologically the brain is formed.

I did find a couple of articles but I had to pay for them to get all the information.(cheap)

I guess I just put sites that relate to the subject?

I will find work on it tomorrow ,

What type of evidence would you like to see?

thanks

[Peripheral]

Originally Posted by pooka

I

I'm not convinced that that makes much sense. If this is what you're saying, then it becomes a chicken-or-the-egg situation: did the disuse of executive functions cause the ADHD, or did the ADHD cause the disuse of executive functions? And how can one or the other ever be proven?

I appreciate the help, I will work on your question thanks.

[namazu]

Geronimoo,

I would like to understand.

Are you simply trying to educate people about what Dr. Mate writes about neural pruning?

Are you trying to get more information about how neural pruning works?

Are you trying to make a specific point about neural pruning and ADHD?

Are you trying to contrast neural pruning with other developmental processes, or to show how they are related?

Please help me understand.

[Peripheral]

Originally Posted by namazu

Geronimoo,

I would like to understand.

Are you simply trying to educate people about what Dr. Mate writes about neural pruning?

Are you trying to get more information about how neural pruning works?

Are you trying to make a specific point about neural pruning and ADHD?

Are you trying to contrast neural pruning with other developmental processes, or to show how they are related?

Please help me understand.

Thank You so much!

...Neural Darwinism.

Without the requisite stimulation during the critical period allotted by Nature for the visual system's development,

the child's brain would never have received the information that being able to see is needed for survival.

Irreversible blindness would result..



What is true for vision is also true for the dopamine circuits of incentive-motivation and the opioid circuitry of attachment-reward,

as well as for the regulatory centers in the prefrontal cortex,

such as the orbitofrontal cortex-..._Dr.Mate

What is Mesolimbic pathway.

http://en.wikipedia.org/wiki/Mesolimbic_pathway

Light is the requisite stimulation for the visual system's development,

What is the requisite stimulation for the Mesolimbic_pathway systems development?



Is there rules to evidence based disscussions?


There is no disagreement that there can be a ADHD genetic sensitivity.


Could understanding the application of requisite stimulation for the mesolimbic pathway,

lessen the severity of ADHD in childhood during the critical period allotted by Nature for the Mesolimbic system's development?



As light, is to visual system's development

"?", is to the Mesolimbic system's development?


Thanks for the support!
Its interesting, EH?

[pechemignonne]

There is no disagreement that there can be a ADHD genetic sensitivity.


Could understanding the application of requisite stimulation for the mesolimbic pathway,

lessen the severity of ADHD in childhood during the critical period allotted by Nature for the Mesolimbic system's development?

No, but it could help kids with attachment disorders. ADHD is not an attachment disorder, it does not develop because a of lack of stimulation for the mesolimbic pathway. Most children with ADHD do not have attachment disorders.

I really think that your inability to distinguish between the two disorders is causing you confusion. All of the posts you have put forward are relevant to attachment disorders, depression, possibly schizophrenia, and other mental health conditions. But not ADHD.

In terms of the example of blindness, ADHD would be like inherited or traumatic blindness. There would be no purpose in investigating the effects of light sources on infants who had either inherited or traumatic blindness, because you know that the blindness in their case does not stem from that cause.