HOW GABAA RECEPTORS ARE CREATED AND BENZO INDUCED CHANGES

[[su...]]

Hi guys,

I'm no genetic expirt myself, but have been looking at this thread with considderable interest, as this info tends to exactly confirm a theory I've had in my own mind about WD being far more a glutamate problem than gaba as usually assumed on this forum.

 

This also seems to be born out by my personal findings, and others, as well, on this thread about ginkgo Biloba.

http://www.benzobuddies.org/forum/index.php?topic=81617.0;topicseen

In a nutshell, as I understand it, Ginkgo has 2 substances of interest here.

ginkolite, and bilobalite.

The ginkgolite has a halflife of about 11 hours, and is found to be a gaba receptor blocker.

Devant originally considdered this to be of interest, as it should up regulate gaba receptors in some form if taken for a time.

The bilobalite as I recall has a halflife of around 3 hours, and inhibits release of glutamate.

This would, imho cause up regulation of the glutamate receptors, or increased release later on as a rebound effect.

What we all seemed to experience was a wave for about 2 days when initially taking ginkgo, (probably the gaba blocking taking effect, followed by a daily calming effect after taking ginkgo each morning, but around the 13 to 14 hour mark, a quite nasty anxiety spike and bad sleep around 1AM the following morning.

This would all

calm down again the next morning after taking the next ginkgo tablet.

As the gaba receptor blocking has a way longer half life, the 1AM effect is most likely the glutamate rising up with gaba receptors still well blocked.

I found, and I think 1 or 2 others involved in the experiment also have, that 2 or 3 days out from stopping ginkgo that we had a wave.

I believed this to be the rebound of the suppressed glutamate system that may have been up regulated by intermittently blocking it with the bilobalite.

Alas, I can't say my overall experience with doing the experiment seems to have helped me, in fact, perhaps somewhat the opposite, but I encourage you guys to have a read through it, as I think it lends quite a bit of evidence that the active glutamate phase of WD you are proposing here may be right on the mark!

Cheers: and keep up the good work!

 

[[mr...]]

Hey guys-

 

I ended up calling the PhD I had sent an email to who had done a ton of research into the Glutamate Hypothesis.  Her name was Dr. Tietz and she worked at the University of Toledo.  The secretary who answered the phone informed me that she is retired.  She asked me why I was calling and after I explained the reason she put me on hold and called some of the other researchers who knew her.  when she came back she informed me that they told her that no one was carrying on her work--which was a real blow as I think she could have answered so many questions for us.  Here is a link to her old University of Toledo web page that discusses the type of research she was doing:

 

http://www.utoledo.edu/med/depts/physpharm/faculty/tietz.html

 

 

Here are links to some of the research she was involved with which are also the papers I am currently mulling over:

 

http://www.nature.com/npp/journal/v29/n11/full/1300531a.html#fig5

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904841/

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3014299/#!po=2.00000

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399473/

 

 

I think there is another group in the Netherlands looking into this.  I will try to see if I can contact them through Skype.  Let's hope that another group will carry on the work she started.

 

 

 

 

 

Hi Perseverance,

Have you ever read Dr Russell Blaylocks book, "Excitoxins, the taste that kills"?

He has research papers as well on excitoxins, such as glutamate.

http://www.russellblaylockmd.com/

 

[[Mo...]]

 

this is austrian-stupy again.

i have a question , DEAR HELPME

first of all thanks for this importand threat. its about GLUTATHIONE; am i right considering

that dr. schuesslers cell salts could be of some significance ?

thnaks claudia

[[Pe...]]

Braban-

 

While reading through the article you linked:

 

"Glutamic Acid Decarboxylase and Glutamate Receptor Changes During Tolerance and Dependence to Benzodiazepines"  http://www.pnas.org/content/98/6/3483.full

 

I thought this was an interesting observation-

 

"...the levels of GluR1 mRNA were significantly increased in frontal cortex (48%), occipital cortex (38%), and hippocampus (56%), but failed to change in the cerebellum of 96-hr diazepam-withdrawn rats when compared with 96-hr vehicle-withdrawn rats. Notably, the increase in GluR1 mRNA expression detected in the frontal cortex and hippocampus of 96-hr diazepam-withdrawn rats was either not detectable or not statistically significant after 12 or 48 h of diazepam withdrawal."

 

I wonder if there was an increase in GluR1 homomeric receptors.  In the hippocampus, most synaptic AMPARs are heteromeric because they are composed of combinations of different subunits, e.g. GluR1/2 or GluR2/3, with the GluR2 subunit preventing Ca2+ influx. However, a small number of Ca2+-permeable GluR1 homomeric receptors (meaning they contain only one type of subunit- GluR1) reside in extrasynaptic locations where they can be rapidly recruited to synapses during synaptic plasticity through lateral diffusion.

 

I also found it interesting that the pattern matched the temporal fashion of the silent and active phases.

 

 

Hey Braban-

 

Looks like I was on the right track- read this:

 

"Distinct from NMDAR-dependent LTP, in which Ca2+ influx primarily through NMDAR initiates CaMKII activation and AMPAR potentiation, Ca2+ entry during benzodiazepine withdrawal may primarily occur through an increase in high voltage-activated Ca2+-channel current; and perhaps subsequently, through the increased density of Ca2+-permeable, GluA1 homomeric AMPARs."

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904841/

 

(NOTE- GluA1 and GluR1 are used interchangeably- they both refer to the same subunit)

 

[[Pe...]]

Hi guys-

 

I need help obtaining the full text of one more document, which I will give the link to at the end of this post.  It is a study that could potentially give a whole new meaning to 'distraction' and 'time' being a sx remedy and the cure for WD respectively.

 

First, it is important that you understand what Long-Term Potentiation (LTP) is- here is a good explanation:

 

“It was Santiago Ramon y Cajal who, over 100 years ago, contemplated the idea that changes in the strength of synaptic connections between neurons could be the way in which the brain stores information. The discovery of long-term potentiation (LTP) in the hippocampus in 1973 provided the first evidence that this may be the case. LTP is the enhancement of synaptic strength that results from synchronous firing of connecting neurons, whereas its counterpart long-term depression (LTD) is the weakening of synaptic strength. These processes usually involve N-methyl-D-aspartate (NMDA) receptor-mediated trafficking of α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate (AMPA) receptors to and from the cell surface. An NMDA receptor-mediated increase in calcium levels in the postsynaptic cell is required for the induction of LTP and LTD, with the amount of calcium determining the sequence of events. Large increases in calcium preferentially activate protein kinases and result in LTP, ultimately expressed as enhanced transmission at postsynaptic AMPA receptors. In contrast, more modest increases in calcium preferentially activate protein phosphatases and produce LTD, which is expressed as a decrease in AMPA receptor transmission. While LTP and LTD were initially studied in relation to learning and memory in the hippocampus, they are now known to occur at most excitatory synapses throughout the central nervous system, and are important for many forms of experience-dependent plasticity.”

 

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3495339/

 

As you can see, scientists believe that LTPs are the foundations for memories.  The article goes on to point out that drugs that cause dependence can share this property:

 

“A pioneering study by Ungless and colleagues in 2001demonstrated that a single exposure to cocaine caused an enhancement of synaptic strength at excitatory synapses on VTA DA neurons when measured 24 h later in brain slices. This was measured as an increase in the ratio of AMPA-mediated excitatory postsynaptic currents (EPSCs) over NMDA-mediated EPSCs (termed the AMPA/NMDA ratio). Subsequent electrically-evoked LTP was shown to be occluded at excitatory VTA synapses in cocaine-treated mice whereas LTD was enhanced. These observations as well as a number of other electrophysiological measures indicated that the change in plasticity observed potentially shared similar mechanisms to synaptically-evoked LTP. It has since been shown that administration of other drugs of abuse including amphetamine, morphine, ethanol, nicotine, and benzodiazepines can also induce increases in synaptic strength in the VTA, an effect that is not seen with psychoactive drugs that do not have abuse potential. This observation demonstrates a convergence of cellular responses within the VTA by all abused drugs and provides a possible neural mechanism by which initial neuroadaptations underlying addiction could be triggered.”

 

Studies at the Medical College of Ohio confirmed that the criterion necessary to establish LTPs emerge during withdrawal from benzodiazepines:

 

“Activity-dependent changes in synaptic function are primarily the consequence of intracellular Ca2+-dependent biochemical cascades and involve changes in synaptic AMPAR number and/or function (Hayashi et al, 2000; Song and Huganir, 2002). A GABAR-mediated depolarizing potential, which is present in 2-day FZP-withdrawn CA1 neurons (Zeng et al, 1995), has been shown to activate NMDARs (Staley et al, 1995) and may contribute to increased postsynaptic Ca2+-mediated signal transduction. Thus, in the context of BZ withdrawal, the initial trigger for AMPAR upregulation, though as yet unidentified, may also involve Ca2+-mediated mechanisms similar to that which occur during other forms of activity-dependent neuronal plasticity (Nestler, 2001b).”

 

http://www.nature.com/npp/journal/v29/n11/full/1300531a.html

 

Later, the Ca2+-mediated mechanisms where deemed to be high-voltage activated (HVA) L-type ca(2+) channels:

 

“Moreover, as in benzodiazepine-withdrawn rodents associated with signs of physical dependence, cocaine sensitization was also associated with an enhancement of Ca2+ entry through L-type voltage-gated Ca2+ channels. Accordingly, the sources of Ca2+ entry during drug withdrawal, the resultant effect on CaMKIIα activation, and, in turn, AMPAR potentiation in specific brain areas might in part explain the differences detected among models of activity-dependent and drug-induced plasticity.”

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904841/

 

When Ca2+ enters a neuron it triggers a cascade of events (which I will not get into at the moment because it is quite involved, lol) that in the end result in strengthened AMPA conductance through upregulation and phosphorylation creating the LTP.

 

In addition to the reasons at the end of the paragraph above, the article explained the difference between memory LTPs and drug withdrawal induced LTPs this way:

 

“AMPAR potentiation in specific brain areas might in part explain the differences detected among models of activity-dependent and drug-induced plasticity.”

 

Next I ran across this article:

 

“Impact of contextual cues in the expression of the memory associated with diazepam withdrawal: involvement of hippocampal PKMζ in vivo, and Arc expression and LTP in vitro.”

 

Abstract

 

“Hippocampal synaptic plasticity has been related to learning and adaptive processes developed during chronic drug administration, suggesting the existence of a common neurobiological mechanism mediating drug addiction and memory. Moreover, protein kinase M zeta (PKMζ) is critical for the maintenance of hippocampal long-term potentiation (LTP) and spatial conditioned long-term memories. Also, a link between activity-regulated cytoskeleton-associated protein (Arc), PKMζ and LTP has been proposed. Our previous results demonstrated that re-exposure to the withdrawal environment was able to evoke the memory acquired when the anxiety measured as a diazepam (DZ) withdrawal sign was experienced. In the present work we evaluated if the memory associated with DZ withdrawal could be affected by changes in the contextual cues presented during withdrawal and by intrahippocampal administration of a PKMζ inhibitor. We found that the context was relevant for the expression of withdrawal signs as changes in contextual cues prevented the expression of the anxiety-like behavior observed during plus-maze (PM) re-exposure, the associated enhanced synaptic plasticity and the increase in Arc expression. Furthermore, intrahippocampal administration of PKMζ inhibitor previous to re-exposure to the PM test also impaired expression of anxiety-like behavior and the facilitated LTP. These results support the relevance of the hippocampal synaptic plasticity in the maintenance of the memory trace during benzodiazepines withdrawal, adding new evidences for common mechanisms between memory and drug addiction that can be intervened for treatment or prevention of this pathology.”

 

https://www.ncbi.nlm.nih.gov/pubmed/22759216

 

This is the article I need full access to.  If anyone can help I would certainly appreciate it.

 

I am trying to figure out if there are any correlations and/or shared characteristics between memory and withdrawal sxs since both appear to result from LTPs, despite potential differences in how each is initiated.

 

 

 

[[Pe...]]

 

Hi Perseverance,

Have you ever read Dr Russell Blaylocks book, "Excitoxins, the taste that kills"?

He has research papers as well on excitoxins, such as glutamate.

http://www.russellblaylockmd.com/

 

I don't know if I have read his work in particular- but I am aware of things like MSG, gluten, and perhaps umami (sp?) which I think from the sound of it would probably be things he might discuss.  If I get time I will try to read through the link you provided- I am currently busy trying to wrap up the Glutamate Hypothesis before I go on vacation.  Until then hopefully there are others here who are familiar with his work and can offer input.

[[Pe...]]

This question is for perseverance , please and thank you, Is it possible that chemicals in our body can flow throughout from our Brain so much that we can feel it not by only pain but by sensation, as well as taste it. I had a test down for glutamate , it was off the charts , the test was done through urine, I wonder if that's what's flowing , or is other toxins in my body??? what are  symptoms of neuro toxicity of glutamate? any one know this? I just recently had a test done by my family Dr for Dopamine, Norepinephrine, and epinephrine, my 24 urine creatinine levels showed in Volume was high , but the normal counts were normal . I am dng a hair analysis test for metal and it tests for any lack of minerals , I had a Live blood count test done it was normal , white blood cells and red blood cells were normal . My muscles in my throat feel like they are actually compressing and squeezing the nerves , I am not sure if that's possible ? is it? The nerve pain I endure is actually effecting and cusing nerve damage although I can still use my muscles. My mouth gets a severe pain as if its being compressed of the nerves . My Entire body feels this throughout. I started Glutathione by immunacal , its seems to help some, I had a test done by Genovations , it indicated that I am absent of Gluthione from the Liver/Gut , I will send an article on it.  bUT WHE I HAD A TEST DONE BY 23ANDME DNA it showed I had no issues of Detoxing. IDK so confusing .

 

 

6. Methylation nutrients (folate and vitamins B6 and B12). These are perhaps the most critical to keep the body producing glutathione. Methylation and the production and recycling of glutathione are the two most important biochemical functions in your body. Take folate (especially in the active form of 5 methyltetrahydrofolate), B

6 (in active form of P5P) and B12 (in the active form of methylcobalamin).

 

Hi Laura,

 

I am not real familiar with the neurotransmitter levels tests- I think they test for metabolites in the urine?  Hair analysis test are great to check metals.  I think you were close to perhaps answering your own question with the Glutathione- I know that it is part of the Methyl cycle and therefore the MTHFR gene mutation you have may be interfering with that.  Have you looked into finding a MTHFR wise doctor?  Some mutations can cause things like chemical sensitivities.

[[Br...]]

Hiya Pers.  I looked into glutamate receptors but found their complexity was greater than the GABA receptors so I didn't go into all their details.

 

However I do see in your quotations repeated references to the importance of limiting calcium ion flow in certain glutamate receptors.  By chance, I found out for myself that I experienced improvement in benzo cognitive difficulties when I took a particular calcium channel blocker (nimodipine) which acts preferentially on the cerebral arteries.  It was a really valuable find for me although I have found no one else who has had the opportunity to try it.

 

However we have strayed a bit from the topic. I was saying that I found nimodipine very useful for cog fog from benzos although that may be due to my particular reaction to benzos which I have some reason to believe is untypical as it involves frequent moments of outright confusion. I have tried nifedipine many times but it doesn't do anything at all for me. I only mentioned it in this thread because there was passing reference in Wikipedia to one of memantine's action being the blocking of calcium channels. However as far as I can tell memantine does a whole lot more too - especially in regulating glutamate.

 

We have somewhat hijacked Bart's thread because he was drawing attention to memantine. I think we should not overlook the value of memantine in helping with other more general symptoms of excess glutamate. I would be extremely happy to be a lab rat for memantine if I could get some but I think it may be difficult for me to get! I wonder if others can obtain it more easily?

 

http://www.benzobuddies.org/forum/index.php?topic=79347.msg1048866#msg1048866

 

As an aside.... I don't know where in this puzzle calcium channels fit in but I find a particular calcium channel blocker medication reliably works wonders for me.  I'm aware that one type of glutamate receptor involves calcium but of course that doesn't really amount to a sound theory because my personal understanding of the various glutamate receptors is even poorer than my limited understanding of GABA receptors!  To complicate the picture further there are several types of different calcium channels. 

 

All of which means I have no rigorous understanding of what's going on but what I do know is that Nimodipine 30mg reliably removes a large number of my benzo withdrawal symptoms.  However its duration of action is only a matter of hours and it needs repeated dosing (for example when it is prescribed for those who find it useful for migraines or for those taking it post-stroke).  One author writes that the degree of cerebral vasodilation produced by Nimodipine is not particularly significant and proposes that it's action is to suppress a glutamate storm.

 

http://www.benzobuddies.org/forum/index.php?topic=75253.msg1017153#msg1017153

 

With regard to getting scientific papers, I have found Huraqan a real star in downloading a few scientific papers for me.  If you ask him direct he may be able to help you out.

[[Pe...]]

You are one sharp girl Braban.

 

Yes and Yes.

 

The first Yes- Glutamate receptors are quite different than GABARs.  For instance, glutamate is not the only agonist for the NMDA receptor. Glycine is a co-agonist and both neurotransmitters must bind in order for the receptor to function (glycine binds to the GluN1 subunit while glutamate binds to the GluN2 subunit) as well as the release of the Mg2+ block through depolarization.

 

As I noted earlier, most synaptic AMPARs contain a GluA2 (aka GluR2) subunit which as a general rule makes them impermeable to Ca2+.  However homomeric GluA1 AMPARs that do not contain the GluA2 subunit are Ca2+ permeable.

 

To make things more complex the calcium permeability of the GluA2 subunit is determined by the post-transcriptional editing of the GluA2 mRNA, which changes a single amino-acid in the TMII region from glutamine (Q) to arginine ®. This is called the Q/R editing site.  GluA2(Q) is calcium permeable whilst GluA2® is not.  Almost all the GluA2 protein expressed in the CNS is in the GluA2® form.

 

 

The second Yes- The cascade of events begins with Calcium (Ca2+) entering the neuron.  One article I quoted said the level of the Ca2+ influx determines the effect.  Memory LTPs begin with a depolarization level high enough to cause the Mg2+ to dislodge from the NMDA receptor.  Mg2+ physically blocks Ca2+ from entering the neuron through the NMDAR.  Once it is gone, Ca2+ can flow through the NMDAR into the neuron.

 

A depolarizing event in WD (maybe from lack of Cl- or a bicarbonate (HCO3-)-dependent GABAAR-mediated depolarization--- I have yet to see an article that has given the definitive answer to this) does one or both (again there are conflicting studies)- 1) causes the NMDA Mg2+ to release  2) causes the high-voltage activated (HVA) L-type Ca2+ channels to open. Either way calcium enters the neuron.

 

OK- I am going to go ahead and give you all of the steps involved in the Glutamate Hypothesis---I need to put this out anyway as I am going to be going on vacation and do not want to leave everyone hanging, lol.  Here goes--

 

The Calcium enters the neuron and binds to the enzyme calmoduline.  When 4 calcium ions bind to calmoduline it becomes active Ca2+/camodulin.  Ca2+/calmodulin then in turn activates the enzymes adenylate cyclase and Ca2+/calmodulin-dependent protein kinase II (CaMKII).

 

CaMKII in turn potentiates synaptic transmission through post-synaptic modifications in 2 ways- first- through phosphorylation of the AMPA receptors which enhances single-channel conductance, and second- by facilitating the insertion of new receptors into the membrane (CAMKII phophorylates Ras at its RasGAP thereby activating it.  Ras inturn activates MAP3K, which then activates MAP2K, which activates MAPK.  MAPK can now activate a transcription factor).

 

As I said earlier, Adenylyl cyclase may also be activated by Ca2+/calmodulin, which then converts adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP).  cAMP then activates protein kinase A (aka--PKA, cAMP-dependent protein kinase).

PKA then Phosphorylates S845 on GluA1, which primes extrasynaptic receptors for synaptic insertion into the membrane (PKA is targeted to GluA1 through binding to A-kinase anchoring protein (AKAP) 150 in a complex with PSD-95).

 

PKA also can phosphorylate specific proteins that bind to promoter regions of DNA, causing increased expression of specific genes by translocating to the cell nucleus, where it activates a CREB protein, which in turn binds the cAMP response element (CRE) region on the DNA.  A CREB-binding protein (CBP) then binds and activates it allowing it to switch certain genes on or off.

 

So there you have it- all of the steps (that I know of) in which the AMPARs might be phosphorylated and upregulated resulting in an LTP.

 

Now, regarding the nimodipine.  I am curious about what would happen if this was given at the same time the benzodiazepine was discontinued (prior to WD sxs appearing).  Could it have stopped this cascade of events by preventing/reducing the Ca2+ influx?

 

The memantine was interesting as well.  Some researchers think that LTPs might be involved in some diseases like Alzheimers or Parkinson’s Dementia and for that reason they have been studying this drug on those patients (obviously there are different types of LTPs since we all have memories and not everyone gets these diseases).  That is a serious medication and is nothing to sneeze at.  I would not want to be the gunea pig.

 

If Dr. Tietz ever gets in contact with me I will ask her what she thinks about the nimodipine.

 

I will try to contact Huraqan if no one else steps forward to help out getting full access to the research paper I noted.

 

 

 

[[mr...]]

I don't know if I have read his work in particular- but I am aware of things like MSG, gluten, and perhaps umami (sp?) which I think from the sound of it would probably be things he might discuss.  If I get time I will try to read through the link you provided- I am currently busy trying to wrap up the Glutamate Hypothesis before I go on vacation.  Until then hopefully there are others here who are familiar with his work and can offer input.

He is a retired neurosurgeon an maybe able to answer some of your questions.

He is quite a few research papers on excitoxins.

[[he...]]

I sincerely believe we all have MTHFR issues , its in our DNA, that's why we are protracted , I believe there's got to be a common denominator with us all somewhere along the way, if we have any blockage that is MTHFR issues . That's my personal belief, as I had way over the count of testing done, the C4a Testing is a marker for inflammation , its one of the Complement testing , as is Ca2 , they say is the Ca2 is elevated its an indication of Lyme IDK , everything is an indication of Lyme , as is high glutamate , and Lyme is over rated .What it truly is the innate immune system , its an inflammatory marker of our bodies protecting us . I feel we all have been exposed to heavy metals, Mold etc... what my NP Dr said that its bio chemical and what happened along the way is that whatever exposure we had throughout our years where we had NO issues before that's because of Immune system wasn't compromised , and coming off benzos it compromised our CNS,so along the way any exposure to any toxins of that matter got blocked along the way , and is making our symptoms exacerbate , , because its just not GABA , Receptors that are now effected its a snowball effect. That's the NP theory , to me it makes sense.

[[Pe...]]

You are one sharp girl Braban.

 

Yes and Yes.

 

The first Yes- Glutamate receptors are quite different than GABARs.  For instance, glutamate is not the only agonist for the NMDA receptor. Glycine is a co-agonist and both neurotransmitters must bind in order for the receptor to function (glycine binds to the GluN1 subunit while glutamate binds to the GluN2 subunit) as well as the release of the Mg2+ block through depolarization.

 

As I noted earlier, most synaptic AMPARs contain a GluA2 (aka GluR2) subunit which as a general rule makes them impermeable to Ca2+.  However homomeric GluA1 AMPARs that do not contain the GluA2 subunit are Ca2+ permeable.

 

To make things more complex the calcium permeability of the GluA2 subunit is determined by the post-transcriptional editing of the GluA2 mRNA, which changes a single amino-acid in the TMII region from glutamine (Q) to arginine ®. This is called the Q/R editing site.  GluA2(Q) is calcium permeable whilst GluA2® is not.  Almost all the GluA2 protein expressed in the CNS is in the GluA2® form.

 

 

The second Yes- The cascade of events begins with Calcium (Ca2+) entering the neuron.  One article I quoted said the level of the Ca2+ influx determines the effect.  Memory LTPs begin with a depolarization level high enough to cause the Mg2+ to dislodge from the NMDA receptor.  Mg2+ physically blocks Ca2+ from entering the neuron through the NMDAR.  Once it is gone, Ca2+ can flow through the NMDAR into the neuron.

 

A depolarizing event in WD (maybe from lack of Cl- or a bicarbonate (HCO3-)-dependent GABAAR-mediated depolarization--- I have yet to see an article that has given the definitive answer to this) does one or both (again there are conflicting studies)- 1) causes the NMDA Mg2+ to release  2) causes the high-voltage activated (HVA) L-type Ca2+ channels to open. Either way calcium enters the neuron.

 

OK- I am going to go ahead and give you all of the steps involved in the Glutamate Hypothesis---I need to put this out anyway as I am going to be going on vacation and do not want to leave everyone hanging, lol.  Here goes--

 

The Calcium enters the neuron and binds to the enzyme calmoduline.  When 4 calcium ions bind to calmoduline it becomes active Ca2+/camodulin.  Ca2+/calmodulin then in turn activates the enzymes adenylate cyclase and Ca2+/calmodulin-dependent protein kinase II (CaMKII).

 

CaMKII in turn potentiates synaptic transmission through post-synaptic modifications in 2 ways- first- through phosphorylation of the AMPA receptors which enhances single-channel conductance, and second- by facilitating the insertion of new receptors into the membrane (CAMKII phophorylates Ras at its RasGAP thereby activating it.  Ras inturn activates MAP3K, which then activates MAP2K, which activates MAPK.  MAPK can now activate a transcription factor).

 

As I said earlier, Adenylyl cyclase may also be activated by Ca2+/calmodulin, which then converts adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP).  cAMP then activates protein kinase A (aka--PKA, cAMP-dependent protein kinase).

PKA then Phosphorylates S845 on GluA1, which primes extrasynaptic receptors for synaptic insertion into the membrane (PKA is targeted to GluA1 through binding to A-kinase anchoring protein (AKAP) 150 in a complex with PSD-95).

 

PKA also can phosphorylate specific proteins that bind to promoter regions of DNA, causing increased expression of specific genes by translocating to the cell nucleus, where it activates a CREB protein, which in turn binds the cAMP response element (CRE) region on the DNA.  A CREB-binding protein (CBP) then binds and activates it allowing it to switch certain genes on or off.

 

So there you have it- all of the steps (that I know of) in which the AMPARs might be phosphorylated and upregulated resulting in an LTP.

 

Now, regarding the nimodipine.  I am curious about what would happen if this was given at the same time the benzodiazepine was discontinued (prior to WD sxs appearing).  Could it have stopped this cascade of events by preventing/reducing the Ca2+ influx?

 

The memantine was interesting as well.  Some researchers think that LTPs might be involved in some diseases like Alzheimers or Parkinson’s Dementia and for that reason they have been studying this drug on those patients (obviously there are different types of LTPs since we all have memories and not everyone gets these diseases).  That is a serious medication and is nothing to sneeze at.  I would not want to be the gunea pig.

 

If Dr. Tietz ever gets in contact with me I will ask her what she thinks about the nimodipine.

 

I will try to contact Huraqan if no one else steps forward to help out getting full access to the research paper I noted.

 

One thing I wanted to add is that there are two phases of LTP- early phase (E-LTP, aka LTP1) and late phase (L-LTP, aka LTP2).

 

During the E-LTP phase, Calcium enters the neuron, binds to the enzyme calmoduline, which then becomes Ca2+/camodulin.  Ca2+/calmodulin then activates the kinases CaMKIIa an PKC (Protein Kinase C) which phosphorylate existing AMPARs, increasing their single channel conductance, and also through phosphorylation traffick a nonsynaptic pool of extrasynaptic AMPA receptors (adjacent to the postsynaptic area) into the synaptic area (through lateral diffusion) which increases the number of AMPARs at the synapse- which also increases the AMPA synaptic strength/conductance.  The important thing to remember about this phase is that the increase in AMPAR number at the synapse is through lateral diffusion of EXISTING receptors that were already made- not ones that have yet to be synthesized.

 

Next comes the late phase.  Unlike E-LTP, which is INDEPENDENT of protein synthesis, in the L-LTP phase, new AMPARs are synthesized through gene transcription.  This second phase begins a little later after CaMKIIa phophorylates Ras at it RasGAP, which activates it.  Ras inturn then activates MAP3K, which then activates MAP2K, which activates MAPK.  MAPK can now activate the transcription factor initiating production of new AMPARs.

 

L-LTPs are then thought to be maintained by Protein kinase M zeta (PKMζ), which does not have dependence on calcium, which becomes autonomously active.  If this is the case in BW- calcium channel blockers would not be the answer.  It could potentially block this cascade of events from initiating- however once this calcium independent mechanism gets activated, it may be too late for it to have any significant effect.

 

I hope that everyone here tries to understand what I said previously and what I just added because this is what happens on the Glutamate side of things and how LTPs are set up.  I am going to be going on vacation and it is my hope that you all will do your best to understand it all.  Here again is a list of the papers Dr. Tietz was working on. The information I gave you should help you understand her research.

 

http://www.nature.com/npp/journal/v29/n11/full/1300531a.html

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2904841/

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3014299/#!po=2.00000

 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3399473/

 

If you are just coming into the conversation it may help you to read another thread I wrote to help you understand the terminology- and then the opening 3 posts of this thread:

 

http://www.benzobuddies.org/forum/index.php?topic=77803.msg1026651#msg1026651

 

I hope that the people who do understand the information will help to answer the questions of the people who do not. 

[[Mo...]]

 

hi perse.

wishing you a wonderful vacation you have deserved it for sure

Ig

and thanks again so interesting

[[he...]]

Perseverance great post, So I was wondering since Glutathione is a precursor to Glutamate so it raises Glutamate would that be not such a great idea to take? what are your thought , Glutathione helps the immune, helps with inflammation and helps with eliminating Toxins , but it raises glutamate , its so complicated to know what to do and what to try .

[[Ba...]]

 

https://www.ncbi.nlm.nih.gov/pubmed/22759216

 

This is the article I need full access to.  If anyone can help I would certainly appreciate it.

 

 

Here. 

[[Pe...]]

Bak233, you are awesome- thanks again. 

 

Laura- I believe that protacted sxs will actually be shown to be the result of LTPs.

 

Everyone- Before I take off for vacation I want to leave you with a link to a video webinar to view while I am gone that describes LTPs and what researchers have learned so far.  I want to warn everyone that this video contains a minute or so of footage that some may find disturbing (well...I did anyway) of lab rats being placed in uncomfortable conditions for the purpose of the study. (you can always fast forward over that part- it will not take away too much from the general discussion should you decide to do so.)

 

Unfortunately this type of animal research may be necessary as LTPs are believed to be involved in conditions such as - drug dependence and WD, PTSD, Anxiety Disorders, Chronic Pain, Alzheimers, phantom limb syndrome- and perhaps other conditions.

 

This video is long- however you can fast forward to 10:00 to skip the rather long introduction.

 

http://www.youtube.com/watch?v=3azByykgfl8

 

 

It is good to see researchers recognize that there are different forms of LTP and that they have been shown to be involved in WD sxs- apparently Dr. Tietz was not the only one who was on to this, which is great news for all of us.

[[Ho...]]

Thank you Pers for all your hard work...I am having a hard time understanding the LTP's...your comment to Laura about LTP's being responsible for protracted w/d is interesting to me but I just can't understand exactly how...is there someone here on this site who could explain this to me in layman's terms? 

    I would really appreciate it...thank you!

Hoping2BFree

[[Be...]]

My understanding after reading all this research is that Long Term Potentiation is caused by our body creating more glutamate receptors called AMPA and rearranging the ones we do have to try to counteract the sedating effects of the benzo's.  This happened in tolerance w/d and then when we discontinued them in w/d.  So we have more glutamate running around in our bodies than we need, causing the anxiety-related w/d s/x's.  As time goes on, these receptors should balance themselves out and get back into equilibrium, which is what the healing is about.  For some people it may take along time such as those who are protracted. 

[[he...]]

http://en.wikipedia.org/wiki/Long-term_potentiation LTP

[[Ho...]]

 

Thank you Becksblue and Helpme....

 

[[Pe...]]

I just finished writing up a paper explaining LTPs and posted it on a separate thread as the topic of this thread is geared more towards the GABA side of things than the glutamate side.  Here is a link to the new thread:

 

http://www.benzobuddies.org/forum/index.php?topic=85498.0

 

We can continue the discussion regarding the glutamate receptors there.   My vacation ended up being postponed so I sat down and put that paper together instead.

 

I hope the paper I wrote helps to clarify LTPs.

[[Be...]]

I was doing some studying about Long Term Depression, LTP, which helps to rebalance the LTP, so that's the hope for us humans.

[[Bu...]]

 

Can't wait to share this with my husband who IS a molecular biologist and has watched all my suffering while doctors didn't know what to do with me. I will be curious too to hear his thoughts about prospects for potential testing for people susceptible to benzo issues as he is working on related technology for diagnostics in general. (I'll share anything I learn.)

 

I hope you do, we would all be very interested in that.

 

 

Hi Perseverance,

 

Following up on what I learned from my husband, the research scientist. Press release follows. I think it's exciting that this kind of research is happening. Essentially, clinicians are beginning to use new platforms for fast DNA sequencing that can determine whether patients are ultra fast, medium or slow metabolizers of meds to make therapeutic recommendations. It's a step in the right direction...

 

AIBiotech Offering PGx Testing on Ion Torrent, Plans to Expand Clinical NGS Offerings

July 17, 2013

By Molika Ashford

AIBiotech, a contract research organization and clinical genomic testing company, began offering next-gen sequencing-based pharmacogenomic testing using Life Technologies' Ion Torrent PGM earlier this year to physicians and patients through its CLIA-certified and NY State Department of Health-approved lab.

The firm is currently offering an NGS PGx panel available in several different versions to help guide therapy with cardiac, pain, and psychiatric drugs, the company's Founder and Executive Vice President, Thomas Reynolds, told Clinical Sequencing News this week.

Though AIBiotech works with several different sequencing technologies in its CRO activities, including the Illumina HiSeq 2500 and Roche's 454, Reynolds said that when moving forward with its PGx panel the company decided that Ion Torrent would best suit its needs.

"We use each one of these NGS platforms according to their strengths for different projects," Reynolds said. "On the clinical side, we found that for this massively multiplexed panel that the Ion Torrent did the best job." The company is among the first groups to offer clinical testing using the Ion Torrent through a CLIA lab.

AIBiotech's PGx panel for cardiac drugs covers variants in cytochrome P450 genes, including CYP2C9, CYP2c19 and CYP2D6, which are implicated in metabolism of a range of drugs, as well as a number of other targets with relevance to drug response that include Factor V and Factor II Leiden mutations, MTHFR, and ApoE genotype, according to Reynolds.

"Basically, we determine whether people are poor, intermediate, or rapid, or ultra rapid metabolisers, and provide recommendations to [ordering] doctors on [therapeutic implications]," Reynolds said.

The same panel, excluding factor V, factor II, and APOe is offered specifically to inform treatment with pain management drugs, mainly opiates, he added. And another version is targeted at psychiatric drugs.

Before launching its NGS PGx panel, AIBiotech offered PGx testing using real-time PCR and other platforms.

"It was always our goal to set this up on an NGS platform, and it became rapidly clear to us as we grew that we'd have to move toward a more high-throughput system," Reynolds said.

"Also, DNA sequence provides us with [the] depth of coverage and accuracy we were looking for … and allows us to cover a variety of mutations in all 10 genes we are looking at, and [to] multiplex at the same time, much more than with other [technologies]," he added.

Reynolds said the company does plan to expand its clinical NGS offerings, but he declined to detail what disease areas it may target in the future.

He said upcoming decisions about additional panels will be determined primarily by where the company sees the soundest science backing up clinical validity and utility, as well as what it believes it will be able to successfully seek reimbursement for and market.

"We do offer some cancer testing, so that may be an area we go into, but we are going to tread carefully with those three conditions attached to it," Reynolds explained.

The PGx panel is covered by both Medicare and private insurers, Reynolds said. Future tests AIBiotech offers would also have to merit reimbursement.

"We are not going to bring something to market that would not be paid for," he said.

One thing Reynolds said the company definitely does not plan to offer clinically is whole-genome or whole-exome sequencing.

"For the clinic, we want to develop things that we can provide for physicians, actionable information that they can use to actually do something to impact their treatment plan for patients."

Researchers at the Medical College of Wisconsin have also been developing a sequencing-based pharmacogenomics panel on the Ion Torrent PGM with plans to offer it from the college's CLIA-certified and CAP-accredited laboratory (CSN 1/11/2012).

Mount Sinai School of Medicine has also recently said it plans to develop NGS PGx panels for the Illumina HiSeq and potentially other platforms and submit them for NY State approval (CSN 1/16/2013).

[[Re...]]

following..... just to get back here to review