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Showing posts sorted by relevance for query vagus nerve. Sort by date Show all posts
Showing posts sorted by relevance for query vagus nerve. Sort by date Show all posts

Thursday, 17 October 2013

Cytokine Theory of Disease & the Vagus Nerve


If you are a regular reader of this blog you will know that the key to controlling autism is reducing oxidative stress and neuroinflammation.  One of the key drivers of the on-going neuroinflammation are signalling molecules called cytokines; if you can limit the release of harmful cytokines you can reduce neuroinflammation.  This appears to be easier said than done.  I learnt that some statins limit the release of pro-inflammatory cytokines and neuroscientists in the US are researching their use, but not yet in autism.  I did some home research and found a positive effect within 24 hours.
It turns out there is an entire field of neuroscience relating to cytokines as a mediator of disease and this is all channelled through the Vagus nerve.  There is an eminent  neuroscientist, Kevin Tracey, who dominates this field; he is credited with discovering that vagus nerve stimulation inhibits inflammation by suppressing pro-inflammatory cytokine production.   Tracey is also an inventor, he is seeking to apply the science and has an interesting start-up company.  So I have found a kindred spirit and if you read his papers, you will find that often missing element, a sense of humour.
Tracy has even written a book, which explains his discoveries.

Fatal Sequence: The Killer Within

For those scientists among you, a very readable paper is:- 

Physiology and immunology of the cholinergic  Anti-inflammatory pathway

For those in a hurry, here is summary
The cytokine theory of disease is a concept that cytokines produced by the immune system can cause the signs, symptoms, and damaging aftereffects of disease.

One example is the case of TNF, a cytokine implicated as a necessary and sufficient mediator of lethal septic shock. Administration of TNF to healthy humans reproduces the metabolic, immunological, and pathological manifestations of the disease and the gene knockout or pharmacological blockade of TNF activity prevents the development of lethal septic shock. Other pathophysiological activities ascribed to TNF are the capacity to cause fever and localized inflammation. Clinical successes in the 1990s using drugs that specifically inhibit TNF for patients with inflammatory bowel disease or rheumatoid arthritis directly implicated a pathogenic role of this cytokine in other diseases and validated in humans the fundamental premise of the cytokine theory of disease.

 

 
The cholinergic anti-inflammatory pathway

Tracey reasoned that, since the CNS coordinates major physiological responses via innervated circuits, it might also use neural input to control a potentially deadly cytokine response. In classical physiological systems, the sensory projections of the autonomic nervous system provide input to brain networks about essential bodily functions. These elicit a coordinated neural output from the CNS to maintain homeostasis for parameters as varied as heart rate, blood pressure, digestion, body temperature, organ perfusion, and blood glucose levels. Accordingly, it seemed possible to posit the existence of a comparable mechanism to control cytokine release that could, at least in theory, function as an extremely fast, reflex-like anti-inflammatory pathway controlled by brain networks.  Stimulation of vagus nerve signals was shown to significantly inhibit TNF release in animals receiving lethal amounts of endotoxin. Subsequent work established that vagus nerve signaling inhibits cytokine activities and improves disease endpoints in experimental models of sepsis, schemia/reperfusion, hemorrhagic shock, myocardial ischemia, ileus, experimental arthritis, and pancreatitis. The cellular molecular mechanism for inhibition of cytokine synthesis is attributable to acetylcholine (ACh), the major vagus nerve neurotransmitter. Macrophages and other cytokine-producing cells express acetylcholine receptors (AChRs), which transduce an intracellular signal that inhibits cytokine synthesis. The best characterized of these cholinergic receptors that suppress cytokines is the α7 subunit of the nicotinic AChR (α7 nAChR).

 



 
It takes nerve to restrain cytokines: anatomy of an innervated cytokine system

Recent studies of the physiology, functional anatomy, and cellular molecular mechanisms of the cholinergic anti-inflammatory pathway indicate that the principal components for cytokine suppression by the vagus nerve converge in the spleen. Endotoxin localizes to macrophages primarily in the spleen and liver, thereby activating an immediate early cytokine response. The spleen is the major source of both hepatic and systemic TNF during endotoxemia; it releases newly synthesized TNF into the splenic vein, which drains into the liver, and from there, TNF crosses into the systemic circulation.

 Vagus nerve stimulation, or administration of α7 nAChR agonists, inhibits not only TNF but also IL-1, IL-6, IL-8, and high mobility group box 1 (HMGB1)

 



Preclinical efficacy of experimental therapeutics
Preclinical studies are in progress to determine whether it may be possible to develop therapeutics based upon either devices that stimulate vagus nerve activity or drugs that activate the cholinergic anti-inflammatory pathway to suppress cytokine damage. A significant number of studies indicate that the cholinergic anti-inflammatory pathway is a robust regulator of cytokine-mediated damage in local and systemic experimental disease.


The role of exercise
Exercise reduces levels of TNF and other cytokines, confers protection against cardiovascular disease and type 2 diabetes, increases vagus nerve activity, and confers protection against the development of atherosclerosis. It is possible that the mechanism of these exercise effects is at least in part attributable to exercise-induced increases in cholinergic anti-inflammatory pathway activity. Obesity, on the other hand, is characterized by diminished vagus nerve output and elevated cytokine levels, which have been implicated in mediating insulin resistance and atherosclerosis. Since weight loss and exercise are each associated with increasing vagus nerve activity, one can consider whether enhanced activity in the cholinergic anti-inflammatory pathway might decrease cytokine production and reduce the damage and metabolic derangements mediated by chronic, low-grade systemic inflammation that is characteristic of the metabolic syndrome

His conclusion:-

“It is bemusing to think that one of the fundamental premises of the ancient Greeks was that dietary manipulation controlled humoral balances. This concept is now, at least in principle, supported by new evidence of a direct link between dietary composition and the regulation of cytokines by the cholinergic anti-inflammatory pathway. Modern clinical studies have advocated supplementing diet with fish oil, soy oil, olive oil, and other fats to significantly increase vagus nerve activity, reduce inflammatory markers, and improve disease severity in inflammatory bowel disease, rheumatoid arthritis, and cardiovascular disease. These clinical anti-inflammatory responses may be linked to the fat-induced stimulation of the cholinergic anti-inflammatory pathway, as is the case in rats. And now it appears that a major source of systemic TNF during lethal challenges is the spleen, the source of Galen’s black bile. One can’t help but wonder: How did the ancient Greeks know?”

 

Anti-inflammatory activities of vagus nerve stimulation

The discovery by Tracey that vagus nerve stimulation inhibits inflammation by suppressing pro-inflammatory cytokine production has led to significant interest in the potential to use this approach for treating inflammatory diseases ranging from arthritis to colitis, ischemia, myocardial infarction, and congestive heart failure. Action potentials transmitted in the vagus nerve activate the efferent arm of the Inflammatory Reflex, the neural circuit that converges on the spleen to inhibit the production of TNF and other pro-inflammatory cytokines by macrophages there. This efferent arc is also known as the Cholinergic anti-inflammatory pathway Because this strategy targets the release of TNF and other pro-inflammatory cytokines, it may be possible to use vagus nerve stimulation instead of anti-inflammatory antibodies (e.g., Remicade or Enbrel) to treat inflammation. SetPoint Medical, Inc. is an early-stage medical device company, set up by Tracey, developing an implantable  neurostimulation platform for the treatment of inflammatory diseases.

Remicade and Enbrel are ultra-expensive drugs, costing about $20,000 per year.  Not surprisingly, some US autism doctors are wondering what they would do in autism.

My Conclusion

I was wondering if Kevin Tracey might be related to Jeff Tracy, in which case, can Brains please make Monty, aged 10 with ASD,  a vagus nerve stimulation device, preferably with a built-in nuclear power pack.  (I refer to a cult British TV series from the 1960s called Thunderbirds, a favourite of both Monty and his big brother, Ted.)  

 
 

Thursday, 5 April 2018

Transcutaneous Vagal Nerve Stimulation - a Potential Cognitive Therapy?



 Sham device left and the real one on the right


In older posts there was quite a lot written about the vagal nerve and a method of stimulating it, called vagal nerve stimulation (VNS). VNS is already used by many thousands of people with epilepsy; more recently a much milder kind of stimulation has been developed to improve learning after a stroke.
This kind of therapy requires a 40 minute operation to attach the device inside the body. Even though it looks like VNS makes a dramatic improvement in rehabilitation following a stroke, I do not see children without epilepsy being fitted with internal VNS devices any time soon.
Traditionally VNS requires making a connection directly to the main vagus nerve, however the vagus nerve has many branches leading to it.
A German company Cerbomed has created a non-invasive, transcutaneous (through the skin) VNS device (tVNS) that stimulates the afferent auricular branch of the vagus nerve located in your ear.
“This device has received CE approval as indication that it complies with essential health and safety requirements. Thus, tVNS is safe and accompanied only by minor side effects such as slight pain, burning, tingling, or itching sensation under the electrodes.  
Given that the right vagal nerve has efferent fibers to the heart, tVNS is safe to be performed only in the left ear.”
There are several kinds of electric and magnetic stimulation already used in autism - Transcranial Magnetic Stimulation (TMS), transcranial direct current stimulation (tDCS) and ECT.
ECT was covered in this post:-

Manuel Casanova, neuropathologist and bilingual autism blogger is a fan of TMS

Transcranial direct current stimulation (tDCS) is a form of neurostimulation that uses constant, low direct current (DC) delivered via electrodes on the head; it can be contrasted with cranial electrotherapy stimulation which generally uses alternating current (AC) the same way.
It was originally developed to help patients with brain injuries or psychiatric conditions like major depressive disorder.

METHODS:


The authors present a case of an 18-year old patient with ASD treated successfully with tDCS; 1.5 mA of tDCS was applied once a day for 30 minutes for 8 consecutive days with the anode electrode over rTPJ (CP6 in the 10/10 electroencephalogram system) and the cathode electrode placed on the ipsilateral deltoid. Behavioral outcome was assessed using the Autism Treatment Evaluation Checklist prior to tDCS, after the final tDCS session, and at 2 months after tDCS. An additional, informal follow-up was also made 1 year after tDCS.

RESULTS:


Autism Treatment Evaluation Checklist showed substantial improvement in social functioning from baseline to post-tDCS, which was maintained at 2 months. The patient also reported lessened feelings of anger and frustration over social disappointments. Informal follow-up 1 year after stimulation indicates that the patient continues to maintain many improvements.

CONCLUSIONS:


Anodal tDCS to the rTPJ may represent an effective treatment for improving social functioning in ASD, with a larger clinical trial needed to validate this effect.



Conclusions—This study provides the first evidence that VNS paired with rehabilitative training after stroke (1) doubles long-lasting recovery on a complex task involving forelimb supination, (2) doubles recovery on a simple motor task that was not paired with VNS, and (3) enhances structural plasticity in motor networks.








Scientific Explanation of VNS Paired Stimulation for Tinnitus and Stroke Rehabilitation



Each time the vagus nerve is stimulated, it sends a signal up to the brain, which triggers the release of neurotransmitters (acetylcholine and norepinephrine)   broadly across the brain thus enabling neuroplasticity. In effect it is telling the brain to pay attention to the task at hand.
In someone having therapy after a stroke this might be learning to open a jar, but in autism it might be speech therapy.

The image below illustrates the therapy in action. While the patient is performing a rehabilitative exercise, the physical therapist pushes a button, which triggers the wireless transmitter to send a signal to the implanted device to deliver a small burst of electrical stimulation to the vagus nerve.





big clinical trial:-   www.vnsstroketrial.com/

Conclusion 
It does seem that using electricity in one way or another does have some therapeutic effect in some people with autism. The reason it may be effective in some people is not always entirely clear.
Personally, I like the idea of tVNS to potentially give a learning boost during 1:1 therapy to struggling learners with autism, just as VNS is being used in elderly people who have lost function in their limbs after a stroke and need to relearn how to control their muscles.
It appears that the amount of electricity used in stroke patients is much lower (one 60th) than in those with epilepsy. Perhaps it will be possible to develop a tVNS therapy that does cause any discomfort in the patient’s ear.  
Nobody is researching transcutaneous vagal nerve stimulation for improved learning in autism, given that some doctors at leading hospitals like Johns Hopkins do seem to like zapping people with autism, perhaps somebody should. There looks to be more science behind this than some other shock treatments, which do look quite crude, but do seem to help some people.  

Parkinson’s Disease and the Vagal Nerve
We saw in an earlier post that what goes on in the gut is communicated to the brain, bypassing the blood brain barrier, via the vagal nerve.  In that post it was mice who had their vagal nerve severed in the name of science.
Until recently a common therapy in humans with peptic ulcers was to severe the vagal nerve.  It turns out that these people are protected from developing Parkinson’s Disease. Interesting?







Monday, 14 October 2013

IBS, IBD and Autism, leading to Cholinergic Signaling and the Vagus Nerve


This post is all about those stomach problems typical of many kids with ASD and some of their neuro-typical close relatives. Since Monty, aged 10 with ASD, does not have any of these problems, it is not something I have looked into earlier.  As you will see later in this post, by understanding the underlying science, we can move another step towards inhibiting systemic inflammation, which affects all people with ASD.
 
Irritable bowel syndrome (IBS) and Inflammatory Bowel Disease (IBD),
First of all we need to differentiate two common conditions with very similar symptoms.  IBS is the less serious condition, though it causes lots of discomfort.
 
Irritable Bowel syndrome - IBS
Irritable bowel syndrome (IBS) sufferers show no sign of disease or abnormalities when the colon is examined.

IBS does not produce the destructive inflammation found in IBD. It does not result in permanent harm to the intestines, intestinal bleeding, or the harmful complications often occurring with IBD. People with IBS are not at higher risk for colon cancer, nor are they more likely to develop IBD or other gastrointestinal diseases
The exact cause of IBS is unknown.   The most common theory is that IBS is a disorder of the interaction between the brain and the gastrointestinal tract, although there may also be abnormalities in the gut flora and immune system.

Inflammatory Bowel Disease -  IBD
Inflammatory bowel disease is a group of inflammatory conditions of the colon and small intestine. The major types of IBD are Crohn's disease and ulcerative colitis

Crohn’s disease has a strong genetic component and is far more prevalent among smokers.  The usual onset is between 15 and 30 years old.
Ulcerative colitis is an auto-immune disease with no known cause.  The symptoms are very similar to Crohn’s disease, but there are some stark differences.  Ulcerative colitis is far less prevalent among smokers

Autistic Colitis / Ulcerative Colitis
The Inflammatory Bowel Disease (IBD) that seems to be relevant in Autism is ulcerative colitis, so much so that Wakefield and Krigsman sought to name a sub-type Autistic Enterocolitis.  Due to all the furore about vaccinations and autism, the research of these two gastroenterologists has been blacklisted.

Dr Krigsman has an informative website and has published some interesting research.
If you spend all day looking via the endoscope  at children with ASD, you are bound to notice a thing or two.  Ignoring what Krigsman observes is bizarre.

In case you are wondering what he does, he is going through the mouth to do an Upper Endoscopy; for the Colonoscopy he goes in from below.  He does both procedures under general anaesthetic.  That will be painless; I once had an endoscopy under general anaesthetic and you have no bad effects.  I had the misfortune to have another one without any anaesthetic, which was one of the most unpleasant experiences of my life.
Ulcerative colitis looks like a nasty condition but Krigsman finds it is generally treatable with some combination of anti-inflammatory medication, antimicrobials, probiotics, digestive enzymes and dietary restriction.

One thing he does not mention is nicotine, more of that later.

GERD
Gastroesophageal reflux disease (GERD) is a very common disease.  The acid within the stomach rises up into the esophagus and in doing so, damages its lining.

Most children will outgrow their reflux by their first birthday. However, a small but significant number of them will not outgrow the condition. This is particularly true when a family history of GERD is present.   It is estimated that 15% of adults of adults are affected by GERD.
Krigsman find that in kids with ASD and their siblings, GERD is relatively common.

 
Mechanisms linking IBS and IBD to Autism
I have already written about the link between food allergies, autism and behaviour.  In those posts it was histamine released from mast cells (along with cytokines and other nasties) that was the culprit.  The treatments included antihistamines and mast cell stabilizers (Ketotifen, Intal etc).  I would presume this would fall into the IBS category.

When it comes to IBD, things get interesting.
In 1936 the Nobel Prize for Physiology was awarded to Sir Henry Dale and Otto Loewi.  One had identified the neurotransmitter acetylcholine and the other had shown how the vagus nerve releases acetylcholine to control heartbeat.

It later became apparent how important the vagus nerve is.  The vagus nerve is a modulator of inflammation throughout the body.  Acetylcholine, the principle neurotransmitter released by the vagus nerve, can exert its anti-inflammatory effect via binding to nicotinic acetylcholine receptors (nAChRs), which are expressed on macrophages and other immune cells.
 
In a recent post I showed that autistic brain samples have diminished acetylcholine and nicotinic receptor activity.  I showed how this could be corrected either by drugs that mimic acetylcholine (eg nicotine or acetylcholine) or with an acetylcholinesterase inhibitor (Galantamine or Donepezil).

I found it very interesting that IBD can be successfully treated by mild smoking (3 cigarettes a day) or with nicotine patches. 
This then connects various comorbidities in a very useful way and opens up therapeutic directions.  The vagus nerve is also key to epilepsy.  Vagus nerve stimulation is currently used to treat epilepsy and depression.

Experimentally, vagus nerve stimulation is already used in autism.  

CONCLUSIONS:


Patients with ASD and intractable epilepsy respond as favorably as all other patients receiving VNS therapy. In addition, they may experience a number of QOL improvements, some of which exceed those classically observed following placement of a VNS device.

 

Kevin J. Tracey
A neurosurgeon and inventor, Kevin Tracey, is the man behind the inflammatory reflex.  The inflammatory reflex is a neural circuit that regulates the immune response to injury and invasion. All reflexes have an afferent and efferent arc. The Inflammatory reflex has a sensory, afferent arc, which is activated by cytokines, and a motor, or efferent arc, which transmits action potentials in the vagus nerve to suppress cytokine production. Increased signaling in the efferent arc inhibits inflammation and prevents organ damage.
We will be looking at his research and the Cholinergic anti-inflammatory pathway, in later posts


 

Wednesday, 30 October 2013

The Vagus Nerve and Autism

It is good to know that there are some brilliant minds out there, willing to cross disciplines.  A case in point is Professor Stephen Porges, a neuroscientist with particular interests in understanding the neurobiology of social behavior.  He is a Professor in the Department of Psychiatry and the Director of the Brain-Body Center in the College of Medicine at the University of Illinois at Chicago.  He has an equally clever wife who is a world leader in the role of neuropeptides oxytocin and vasopressin in social cognition.
You would want to think twice before inviting this couple round for dinner, unless you had spent the day before boning up on your science. 

Porges is best known for his Polyvagal Theory.  The Wikipedia article does not really do justice to the theory.  Here are two highly cited papers:-

He has only written one paper on autism, it is certainly not a light read but it shows a brilliant mind.

This paper is actually a chapter in a book and can be accessed via Google Books.

His paper explains odd autistic behaviours in terms of the functioning of the vagus nerve.  For example, the neural mechanism for making eye contact is shared with those needed to listen to the human voice.  So if you struggle to make eye contact, you will struggle to listen to what somebody is saying to you.  We can infer that if your ABA program trains you to make eye contact, you will likely become a better listener in the process.  Also, don’t talk to somebody unless you are facing them.
He comments on the regulation of the gut, the vagus and the immune system, vagal regulation of the HPA axis, all with reference to ASD.

Having read his paper you really will need no more convincing to go tune up your child’s vagus nerve. 

Tuning up the Vagus Nerve
Unlike Professor Porges, I like to simplify things so you do not read them more than once.  Clearly Kevin Tracey and Porges are the experts on the vagus nerve, but they do not go as far as telling you what you really want to know – how to improve its function using today's technology.  Fortunately, there is plenty of research on the Cholinergic System, of which the vagus nerve is part.  The following paper is a good example:-


You may recall from my earlier post Biomarkers in Autism: The Cholinergic system, that there are two types of cholinergeric receptors, nicotinic and muscarinic.  This paper is telling us how in autism these receptors are fewer in number than normal and the ones that are there, are not working (binding) as they should.
So this goes some way to perhaps explain why so many odd behaviours can be tracked back to the autistic vagus nerve; it is damaged.



In his paper, Porges is basically telling you to go try a vagus nerve stimulator, of the kind that already exists for epilepsy (see photo above) and Kevin Tracey is developing for arthritis (another inflammatory condition).  Right now this is not very feasible, but chemical stimulation of the vagus nerve does not look beyond the wit of man, using currently available technology.


 

Tuesday, 13 May 2014

“Spray Fire in my Head” and how putting it out with Verapamil links Histamine, IL6, Mast cells, Calcium Channel Cav1.2, and even the Vagus Nerve


After 18 months of researching autism, things are falling nicely into place.  For regular readers of this blog, it may seem that we have uncovered a bewildering number of issues/dysfunctions that need to be addressed by the science.  In fact, when you look closer still, you will see that many of these issues are interrelated and you do not need to treat each one.  Also, it is clear that many different methods can be used to treat the same dysfunction.  The best methods though would be the simplest, safest, cheapest and the ones that address multiple issues at once.

One such little gem is Verapamil, an extremely cheap calcium channel blocker that has been widely used for 30 years for other conditions. 


Spray Fire in my Head

Monty, aged 10 with ASD, suffers from allergies like many children.  I noticed that his pollen allergy provoked a dramatic increase in his autistic behaviors.  Last year I spent time developing a treatment for these summertime autism flare-ups, to avoid summertime misery for all of us.

My final secret weapon was not a commonly known allergy drug; in fact almost nobody would even consider it for this purpose, except those who read the old research.

Where we live, last the weekend the air was full of tree pollen and it was 280 C/ 820 F; so I was expecting a response from Monty.

He soon had red eyes, briefly rolled about on the floor and declared “spray fire in my head”.

In anticipation of the pollen season, for the last few weeks I have been giving him some mast cell stabilizing treatments, but clearly they were not sufficient; so I mixed up some extra verapamil, and as expected, a few minutes later peace was fully restored.

I have told you about channelopathies in previous posts.  Verapamil blocks the calcium channel called Cav1.2, but I did not tell you that in addition to this Cav1.2 channel affecting behavior and heart disease, it also appears to directly affect allergies and even the vagus nerve.

It would seem that one cheap little pill can address all of these issues.


The take-home points from the literature are these:-

Verapamil is very widely prescribed calcium channel blocker, used to lower blood pressure; but in the literature it is shown that:-
  • Verapamil inhibits mast cells and is shown to successfully treat asthma
  • Verapamil is more potent than the allergy drug Azelastine (the best mast cell stabilizing anti-histamine drug available)
  • Verapamil will reduce histamine release and therefore inflammatory cytokine Interleukin-6 (IL6), already elevated in autism
  • Verapamil activates the Gene for IL6
  • Verapamil alters the balance between parts of the autonomic nervous system's function, with a shift toward decreased sympathetic tone and increased parasympathetic (vagus nerve) tone
  • Autism is associated with an atypical autonomic response to anxiety that is most consistent with sympathetic over-arousal and parasympathetic under-arousal.  So increasing the parasympathetic (vagus nerve) tone is desirable.
  
Verapamil, Allergies and Asthma

Pollen allergies are a common trigger for asthma, and since every year many people die from asthma, the underlying science is well researched/understood.

  
Discussion
This study has demonstrated, for the first time, that mast cell tryptase potentiates the contractile response to histamine in human isolated airways. Moreover, this potentiation occurs only in tissues derived from patients whose bronchi exhibit a contractile response to antigen, i.e. which are sensitized. The potentiation was not observed in nonsensitized tissue. The mechanism underlying the tryptase-induced potentiation is related to Ca2+ flux through voltage-dependent channels, since it was inhibited by verapamil.

Inhibition of rat mast cell degranulation by verapamil.

Abstract
Calcium antagonists, e.g. verapamil, prevent exercise-induced asthma. This protective effect may proceed from inhibition of contraction of bronchial smooth muscle, release of mediators by primary effector cells, e.g. mast cells, or both. Therefore, we studied the inhibitory effect of increasing concentrations of verapamil on both in vitro antigen-induced degranulation and ionophore A23187-induced release of labelled serotonin by rat peritoneal mast cells. There was a dose-dependent inhibition by verapamil of both ovalbumin-induced degranulation of mast cells passively sensitized by incubation with mice IgE-rich serum and ionophore-induced release of tritiated serotonin by mast cells previously incubated with (3H)-5HT; the 50% inhibiting concentration was 1.4 X 10(-4) mol I-1 and 5.2 X 10(-5) mol I-1, respectively. An attractive explanation of our results is that verapamil inhibits the antigen-induced release of mediators by mast cells through its calcium antagonist effect. Our results also suggest that the preventing effect of calcium antagonists on asthma may be multi-factorial since other authors have clearly shown that these drugs inhibit contraction of guinea-pig tracheal smooth muscle in vitro.

COMPARATIVE STUDY OF AZELASTINE AND VERAPAMIL IN THE MODIFICATION OF OVALBUMIN SENSITIZED LUNGPARENCHYMAL TISSUES OF GUINEA PIGS IN VITRO

The inhibition of mediator released by Azelastine may help to explain their protective action in anaphylaxis. Our observations are in agreement that Azelastine exerts inhibitory effect on synthesis and release of chemical mediators from mast cell (Chand et al., 1983), including the leukotrienes (Hamasaki et al., 1996).

 Azelastine is a second-generation antihistamine approved for treatment ofallergic conditions. This randomized, double-blind, placebo- and active-controlled, parallel group clinical trial evaluated the efficacy and safety of Azelastine in patients with moderate to-severe seasonal allergic conditions (Shah et al., 2009).  Reussi et al. (1980) have demonstrated the inhibition of release of chemical mediators from mast cells by Ca++ channel blocker in animals in vivo and demonstrate the inhibition of antigen-induced brocho-constriction by Verapamil in sheep, allergic to ascaris sum antigen but Verapamil failed to block in the same non-sensitized animal. It is speculated that calcium channel blocker protect against the allergic broncho-constriction predominantly by preventing the release of chemical mediators from the mast cells.

Fig. 2. Graph shows dose dependent inhibitory effect of Azelastine and Verapamil with the treatment of EC50 ovalbumin. Line in the box indicates the ovalbumin EC50 induced contraction (Control). Each point represent mean of six observationsSyed Saud Hasan et al. 49  On the other hand Henderson et al. (1983) found significant inhibition of allergic response with Nifedipine and Lee at al. (1983) also supported the finding, which observed inhibition of mediator release from human lung in vitro by Verapamil.

   Verapamil in concentration 10-10 g/ml did not exhibit any inhibition but as the concentration increases to 10-9 g/ml showed marked inhibition in contractile effect of ovalbumin EC50 (0.3x10-6). Further increases in concentration of Verapamil i.e. 10-8 g/ml completely antagonized the ovalbumin induced contraction. Azelastine in concentration of 10-9 g/ml (1ng/ml) did not exhibit any inhibition as the concentration increase to 10-8 g/ml showed mark inhibition i.e. 20% contraction to EC50 (0.3x10-6) ovalbumin, when compared before treatment with Azelastine and the concentration 10-7 g/ml antagonized the effect of EC50 (Table and Figure 2).







CONCLUSION It can be inferred from the observations that response produced by antigen can be controlled better with Verapamil than Azelastine and emerging with similar activity regardless of exact mechanism involved.




Verapamil and the IL-6 Gene


Conclusions—The results demonstrate that CCB of all 3 subclasses are capable of activating NF-IL6 and NF-kB. CCB may thus directly regulate cellular functions by affecting the activity of transcription factors independent of changes of intracellular calcium concentrations, an observation that is of interest considering the biological effects induced by CCB.

A major result of our investigations is the discovery of the activation of  transcription factors resulting from CCB treatment. In general, CCB are postulated to exert their biological effects by decreasing the intracellular concentration of calcium ions.1–4 Experimentally, this effect is usually achieved at micromolar concentrations of the drugs. However, accumulating evidence suggests that CCB, used at therapeutically effective doses (ie, at the nanomolar range), activate calcium in dependent signal transduction pathway(s) altering gene expression.14–17 Here, we show that CCB directly activate the transcription factors NF-IL6 and NF-kB in human VSMC, independent of intracellular calcium levels. This is supported by the existence of multiple regulatory regions within the intracellular part of the L-type calcium channel. It remains to be investigated, however, along which signal transduction pathway this action of CCB occurs.


Verapamil and the Vagus Nerve

Two of the most popular subjects on this blog are “autism and allergies” and “autism and the vagus nerve”.

The vagus nerve connects many parts of the body and seems to be a conduit for inflammatory signaling within the body.  It is deeply involved the process leading to arthritis and epilepsy; by stimulating this nerve with electrical signals, both epilepsy and arthritis can be reduced markedly in certain people.  It is often suggested that the GI problems in many autistic people and linked to aberrant behaviors via the vagus nerve, what some call the “gut brain connection”.

To understand what is going on and why is does affect autism we need to introduce something new, the autonomic nervous system.  For those who already know about this, the interesting finding is that:-

Verapamil alters the balance between parts of the autonomic nervous system's function  with a shift toward decreased sympathetic tone and increased parasympathetic (vagus nerve) tone.

The source of this statement is:


and their sources were:-




We learned in an earlier post about autism and the Vagus Nerve that it seems to link many strange things in autism.

We learned from Professor Porges that, for example, the neural mechanism for making eye contact is shared with those needed to listen to the human voice; people with autism struggle with both.  Anything that can “wake up” the vagus nerve system could be interesting.
  

In the complicated science we will see that the vagus nerve is also called the parasympathetic nervous system.  The paper below shows how this parasympathetic (Vagus) system is out of balance with the opposing sympathetic nervous system, this then leads to anxiety commonly found in autism.


Assessment of anxiety symptoms in autism spectrum disorders (ASD) is a challenging task due to the symptom overlap between the two conditions as well as the difficulties in communication and awareness of emotions in ASD. This motivates the development of a physiological marker of anxiety in ASD that is independent of language and does not require observation of overt behaviour. In this study, we investigated the feasibility of using indicators of autonomic nervous system (ANS) activity for this purpose. Specially, the objectives of the study were to 1) examine whether or not anxiety causes significant measurable changes in indicators of ANS in an ASD population, and 2) characterize the pattern of these changes in ASD. We measured three physiological indicators of the autonomic nervous system response (heart rate, electrodermal activity, and skin temperature) during a baseline (movie watching) and anxiety condition (Stroop task) in a sample of typically developing children (n = 17) and children with ASD (n = 12). The anxiety condition caused significant changes in heart rate and electrodermal activity in both groups, however, a differential pattern of response was found between the two groups. In particular, the ASD group showed elevated heart rate during both baseline and anxiety conditions. Elevated and blunted phasic electrodermal activity were found in the ASD group during baseline and anxiety conditions, respectively. Finally, the ASD group did not show the typical decrease in skin temperature in response to anxiety. These results suggest that 1) signals of the autonomic nervous system may be used as indicators of anxiety in children with ASD, and 2) ASD may be associated with an atypical autonomic response to anxiety that is most consistent with sympathetic over-arousal and parasympathetic under-arousal.



The following explanation of the Autonomic Nervous System is edited from Wikipedia.


Autonomic Nervous System (ANS)

The autonomic nervous system (ANS) is the part of the peripheral nervous system that acts as a control system that functions largely below the level of consciousness to control functions,] including heart rate, digestion, respiratory rate, salivation, perspiration, pupillary dilation, micturition (urination), sexual arousal, breathing and swallowing. Most autonomous functions are involuntary but they can often work in conjunction with the somatic nervous system which provides voluntary control.

The ANS is divided into three main sub-systems:

PSNS is often considered the "rest and digest" or "feed and breed" system
SNS is often considered the "fight or flight" system
ENS consists of a mesh-like system of neurons that governs the function of the gastrointestinal system

Depending on the circumstances, these sub-systems may operate independently of each other or interact co-operatively.

In many cases, PSNS and SNS have "opposite" actions where one system activates a physiological response and the other inhibits it. The modern characterization is that the sympathetic nervous system is a quick response mobilizing system and the parasympathetic is a more slowly activated dampening system.

In general, ANS functions can be divided into sensory (afferent) and motor (efferent) subsystems. Within both, there are inhibitory and excitatory synapses between neurons. Relatively recently, a third subsystem of neurons that have been named 'non-adrenergic and non-cholinergic' neurons (because they use nitric oxide as a neurotransmitter) have been described and found to be integral in autonomic function, in particular in the gut and the lungs

Neurotransmitters and pharmacology

At the effector organs, sympathetic ganglionic neurons release noradrenaline (norepinephrine), along with other cotransmitters such as ATP, to act on adrenergic receptors, with the exception of the sweat glands and the adrenal medulla:
  • Acetylcholine is the preganglionic neurotransmitter for both divisions of the ANS, as well as the postganglionic neurotransmitter of parasympathetic neurons.
  • Nerves that release acetylcholine are said to be cholinergic. In the parasympathetic system, ganglionic neurons use acetylcholine as a neurotransmitter to stimulate muscarinic receptors.
  • At the adrenal medulla, there is no postsynaptic neuron. Instead the presynaptic neuron releases acetylcholine to act on nicotinic receptors. Stimulation of the adrenal medulla releases adrenaline (epinephrine) into the bloodstream, which acts on adrenoceptors, producing a widespread increase in sympathetic activity.


 Circulatory system

Heart

Target
β1, (β2): increases
M2: decreases

Other

Target
α2: aggregates
---
β2: inhibits

Endocrine system


Target
α2: decreases insulin secretion from beta cells, increases glucagon secretion from alpha cells
M3:[ increases secretion of both insulin and glucagon.[16][17]
N (nicotinic ACh receptor): secretes epinephrine and norepinephrine


Nerve "Wiring Diagram"

The PSNS (parasympathetic nerve system) is wired together via the Vagus Nerve
The SNS (sympathetic nerve system) is wired together via the splanchnic nerves.





Autonomic nervous system, showing splanchnic nerves in middle, and the vagus nerve as "X" in blue. The heart and organs below in list to right are regarded as viscera.
The viscera are mainly innervated parasympathetically by the vagus nerve and sympathetically by the splanchnic nerves.



Conclusion

For those of you that made it this far, here are my conclusions.

People who have autism and any kind of allergy, be it pollen, food intolerance, asthma or anything similar, might consider asking their doctor to let them trial a very low dose of Verapamil for a couple of days.  The effect is almost instant and so there is no point trialing it for weeks.  Verapamil will lower your blood pressure, in a dose dependent fashion.  The effective autism dose for a severe allergy case is about 1mg/kg.  The half-life varies person to person, so you might need two doses a day, or you might need three.

If you know an adult with severe asthma, look hard and you may see some very mild signs of autism (need for order, anxiety, lack of flexibility etc).

It appears that in all these cases, the gene CACNA1C is misbehaving to varying degrees in different parts of the body.  This gene produces the calcium channel Cav1.2.

You could check if you have the mutated gene, but I do not see the point.  It would only tell you what might happen.  To know what actually has happened, you would need to use proteomics

This emerging science will ultimately be able to provide biomarkers for neurological conditions like autism, depression, bipolar etc, so that the neurologist will know, with certainly, what specific dysfunctions each individual person has.  At that point, behavioral assessments and psychiatry will finally be consigned to history and people will get “smart drugs”, to treat precisely diagnosed neurological dysfunctions.