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Dr. Bob is Robert Hsiung, MD,
bob@dr-bob.orgShown: posts 1 to 6 of 6. This is the beginning of the thread.
Posted by JohnX2 on November 5, 2001, at 1:52:14
What exactly is synaptic plasticity?
Any references to material would be appreciated.-john
Posted by Cam W. on November 5, 2001, at 8:24:47
In reply to synaptic/neuro plasticity?, posted by JohnX2 on November 5, 2001, at 1:52:14
>
> What exactly is synaptic plasticity?
> Any references to material would be appreciated.
>
> -johnJohn - Quickly, synaptic plasticity is the ability of the synapse (connection between two nerve cells) to change. That is, the ability of the nerve cell to make new connections to other nerve cells, reinforce existing connections between nerve cells, and break connections that currently exist between nerve cells. The connections between certain nerve cells, especially those that are involved in memory, are "plastic", or changeable. This changing of synapse location slightly alters a memory, as in working memory, where changes in thinking are occurring "online". Long term potentiation (LPT), as probably happens during dreaming, strengthen these synapes, while long term depression (LTD) weaken them (sorta). The new network circuit that is formed is a changed thought.
So much for quickly. I have no online reference for this, but if you scour Neuroscion, I'm sure that you will find something. - Cam
Posted by JGalt on November 6, 2001, at 8:54:27
In reply to Re: synaptic/neuro plasticity? » JohnX2, posted by Cam W. on November 5, 2001, at 8:24:47
Interesting stuff. I'd wondered what it was before but hadn't looked it up yet... I did some research on it after reading this thread, but only managed to confirm what Cam said rather than finding much to add on to it. Its good to have this information, as it backs up the information I had (both online and personally) about GHB interfering with memory when using it a few consecutive days to go to sleep (since GHB makes your body prefer Stage 4 sleep to dream state).
Posted by Noa on November 6, 2001, at 12:53:06
In reply to Re: synaptic/neuro plasticity?, posted by JGalt on November 6, 2001, at 8:54:27
BTW, I heard a great interview earlier this year with one of the nobel prize winners (in medicine, I guess) who had pioneered the work in how the brain develops new neural pathways by creating new synaptic connections in learning. As usual, I forget the name of the scientist (!) but he made such a good impression on me because he seemed so enthusiastic about it all, had a great sense of humor, and was able to talk about the discoveries (and subsequent discoveries) in a way that was easy to understand.
Posted by SLS on November 6, 2001, at 13:37:34
In reply to Re: synaptic/neuro plasticity?, posted by JGalt on November 6, 2001, at 8:54:27
> Interesting stuff. I'd wondered what it was before but hadn't looked it up yet... I did some research on it after reading this thread, but only managed to confirm what Cam said rather than finding much to add on to it. Its good to have this information, as it backs up the information I had (both online and personally) about GHB interfering with memory when using it a few consecutive days to go to sleep (since GHB makes your body prefer Stage 4 sleep to dream state).
I guess this all relates to memantine and dextromethorphan?What's interesting about memantine is that although it is generally thought to reduce neuroadaptive changes (reduce plasticity), it actually can enhance memory and learning. It is known to improve cognition, especially in dementia. This is sometimes thought of as being paradoxical, but it really isn't. Perhaps memantine is selective as to what, when, and where it inhibits synaptic changes. Since "forgetting" is the result of a plastic event, reducing plasticity would allow memories to persist. Something might be learned "deeper" in that once made, fewer connections are lost during the consolidation process (LPT?).
Just a few plastic thoughts...
- Scott
Posted by Cam W. on November 7, 2001, at 20:48:18
In reply to Re: synaptic/neuro plasticity?, posted by SLS on November 6, 2001, at 13:37:34
> What's interesting about memantine is that although it is generally thought to reduce neuroadaptive changes (reduce plasticity), it actually can enhance memory and learning. It is known to improve cognition, especially in dementia. This is sometimes thought of as being paradoxical, but it really isn't. Perhaps memantine is selective as to what, when, and where it inhibits synaptic changes. Since "forgetting" is the result of a plastic event, reducing plasticity would allow memories to persist. Something might be learned "deeper" in that once made, fewer connections are lost during the consolidation process (LPT?).
>
> Just a few plastic thoughts...
>
>
> - ScottScott - How I understand it, the thoughts need to be altered, however slightly, to "learn" anything. Perhaps memantine stops LTD (long term depression), the loss of connections, but allows LTP (long term potentiation), the adding of connections. If this is the case though, I would think that the slowing of LTD would result in confusion over the longrun, as "disconnections" of synapses would be inhibited (or slowed), resulting in too many, possibly confusing connections (eg. too many connecting neural loops). So a modification of the hypothesis would need to be made. Alas, another case where something is so complex it looks simple. The "excepts" and "buts" win out again (eg. "antidepressants relieve depression by increasing serotonin, 'except' for bupropion").
< sigh > Cam
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