Why Girls don’t get Mild Autism and Why Alpha Females may have Kids with Autism.

You may or may not have seen the 2006 comedy film Borat; it was critically acclaimed in the US, but took a bit of time to become a commercial hit.  It brought to public attention its writer, producer and leading man, Sacha Baron Cohen.

Ted, aged 13 and very neurotypical, is a fan of Borat.

In the autism research community, Sacha’s brother Simon is equally well known.  He is the Director of the Cambridge University's Autism Research Centre and a Fellow of Trinity College.

All very interesting,  Ted’s Grandfather also went to Trinity College Cambridge.  Ted’s brother, Monty aged 10 with ASD, has yet to produce a movie, but he has helped to produce an autism blog.    

As you may have noted on this blog, I am rather disappointed with the autism research coming out of the United Kingdom.  90% of the good stuff is from the US.

The extreme male brain theory of autism

One of the well-known autism theories is from Simon Baron-Cohen, it is called:-

The extreme male brain theory of autism

Simon has been developing his theory that something called “assortative mating” may be at least partly to blame for the spectacular rise in autism diagnoses.

The theory states that when people with strongly “systemising” personalities – the sort of people who become engineers, doctors and computer experts – marry each other and produce children, the effects of this kind of “male brain” are genetically magnified, increasing the chances of producing an autistic child – a child with what Simon suspects is an “extreme male brain”.

Strong “systemisers” are often slightly obsessive, perfectionist and make great scientists and are often extremely talented at music. But they sometimes have difficulties socially interacting with other people – a combination of traits that can blend into the milder end of the autism spectrum.

Some of the sharpest increases in autism diagnoses have been found in Silicon Valley, home to perhaps the largest population of successful systemisers on Earth. Tens of thousands of technicians, engineers and programmers work in the computer industry;  inevitably, many of these people marry each other.

Until relatively recently, being exceptionally bright was not much use to you if you were female. The opportunities for a woman to earn her living through brainpower alone were extremely limited. You could be a teacher, or perhaps, if you were lucky, a doctor.

Going to university was difficult and expensive; most did not even allow girls to study. There were certainly few opportunities for careers in engineering or the sciences.

Brainy women were not even seen as particularly desirable partners. Clever or rich men chose brides on the grounds of looks, “breeding” or both. If she did have a job, many employers would automatically fire a woman the moment she turned up with an engagement ring. So many clever, “systemising” women simply did not marry, or married late and probably had fewer children when they did.

Now everything has changed. Not only have the legal and social barriers to women entering the workplace as equals been largely dismantled, we also have the phenomenon of the desirable “alpha female”.

Fifty years ago many men were scared of smart women. Now, increasingly, alpha males want someone their equal. Fifty years ago, male airline pilots typically married stewardesses; now they marry other pilots. Doctors used to marry nurses; now they marry other doctors.

But the phenomenon of like marrying like may be having completely unexpected consequences.  

The Peter Theory of the Neuroprotective Effect of Female Hormones in Autism

Unlike Simon, I do not have a brother who is a movie star, with a Golden Globe; my brother designs car engines, but his engine did win the International Engine of the Year Award in 2013.

I always wondered why it was that kids with autism are mainly boys and when you do meet an autistic girl, she tends to be at the moderate to severely affected end of the spectrum.  Then there is Simon’s observation that alpha females produce disproportionately more kids with ASD.  Then there is the question as to why Anglo-Saxon countries (Australia, Canada, New Zealand, the United Kingdom, and the United States) but particularly the US, have a higher incidence of autism than the rest of the world; is it really just over-diagnosis?

The hormones Estrogen and Progesterone are known to be highly neuroprotective.  Testosterone may also have some neuroprotective properties, but they seem to be of a lesser extent.   While Estrogen and Progesterone are known as female hormones and Testosterone is the male hormone, both sexes have all three hormones, just in different amounts.  We learnt in an earlier post that the stress hormone Cortisol is neurotoxic.

Imagine an experiment:

On the left, you have a stressed alpha female
 (cortisol↑ testosterone↑ estrogen↓  progesterone↓)

with a male fetus (testosterone↑ estrogen↓ progesterone↓)

On the right, you have a calm beta female
 (cortisol↓ testosterone↓ estrogen↑  progesterone↑)

with a female fetus (testosterone↓  estrogen↑  progesterone↑)  

Then both subjects experience a sharp oxidative shock from the environment.

The beta female, with the female fetus, have a major neuroprotective advantage . They can generally weather the storm; only in severe cases is the neuroprotection overcome and the result is a severely autistic girl. 

The alpha female, with the male fetus, cannot weather even a moderate shock and the result is a mildly affected autistic boy.  The more rare severe shocks, produce severe autism.

The kind of insults that produce damaging oxidative shocks have been well documented by researchers like Abha Chauhan. 

Conclusion

This latest Peter Theory is hopefully flawed, after all, what do you learn about biology in Engineering School and Business School?  There should be much more talented people out there.  If it was correct, it would open up avenues in very simple preventative medicine.


P.S.   I am using a little dramatic license; Simon is actually Borat's cousin, not strictly his brother.

Central Serotonergic Hypoactivity in Autism & Degradation of Tryptophan

 

Today’s post has an impressive title and a year ago I would not have understood it, but it summarizes exactly what may be going on inside the autistic brain.  It fits into the wider puzzle of hormonal imbalances in autism that then manifest themselves into behaviours ranging from qwerky to extreme self-injury.

Human emotions and behaviours are influenced by parallel signals from the nervous system (i.e. the brain) and the endocrine system.  The two systems are interconnected and so your state of mind in controlled by hormones that you cannot directly control and the nervous system which you can learn to control.  For example, you can make yourself happy, unhappy, or depressed with the power of your mind.  You can train yourself to overcome fear.  Some people are clearly very much better at doing this than others; but the potential to do so lies within all of us, autistic or neurotypical.  This also explains why singing makes you happy and rapidly reduces cortisol, your stress hormone, as we learnt in an earlier post.

So on the one hand we need to understand any in-built hormonal disturbances in autism and then see how to best tackle them using the hormonal system and the nervous system.  This may sound like fantasy but the more you learn about it, the more plausible it becomes.

Serotonin

Most people have heard of Serotonin; it is frequently thought of as the “happy hormone”.

As we have learnt in this blog, the human body is not like any man-made invention, it seems to function in quite irrational ways.  Serotonin is found mainly in the intestines and less than 10% is in the brain (and CNS), but it is not the same serotonin.  Serotonin cannot cross the blood brain barrier.  In autism serotonin in the blood (produced in the intestines) tends to be elevated, but the level of serotonin in the brain appears to be reduced.  So there appears to be a failure in the entire serotonin system, the one for the brain and the one for the blood.

Drugs that lower brain serotonin are often used to treat the symptoms of autism.  Even Temple Grandin admits (on her own website) to being on a low dose of Prozac to control her anxiety.  In spite of a long list of side effects, many children with ASD living in the US are prescribed this serotonin lowering drug.  Prozac is a heavily prescribed antidepressant drug and is a selective serotonin reuptake inhibitor (SSRI).

Somewhat bizarrely, Prozac is linked to an increase in suicidal tendencies.  As is often the case, many drugs have secondary or tertiary modes of action; you will experience all of them.

In the language of your doctor, low brain serotonin would be called central serotonergic hypoactivity, but don’t go asking him to test it, because he cannot.  All he can do is measure the level of serotonin in the blood or urine, and probably tell you that it is slightly elevated and not to worry.

Researchers have known about this serotonin paradox in autism for many years.  To my surprise a researcher at Yale University even made a mathematical model to better understand it. 

Serotonergic paradoxes of autism replicated in a simple mathematical model

Since the early 1960s, the most consistent pathophysiological finding in autistic individuals has been their statistically elevated blood 5-hydroxytryptamine (5-HT, serotonin) levels. However, many autistic individuals have normal blood 5-HT levels, so this finding has been difficult to interpret. The serotonin transporter (SERT) controls 5-HT uptake by blood platelets and has been implicated in autism, but recent studies have found no correlation between SERT polymorphisms and autism. Finally, autism is considered a brain disorder, but studies have so far failed to find consistent serotonergic abnormalities in autistic brains. A simple mathematical model may account for these paradoxes, if one assumes that autism is associated with the failure of a molecular mechanism that both regulates 5-HT release from gut enterochromaffin cells and mediates 5-HT signaling in the brain. Some 5-HT receptors may play such a dual role. While the failure of such a mechanism may lead to consistent abnormalities of synaptic transmission with no alteration of brain 5-HT levels, its effects on blood 5-HT levels may appear paradoxical.

 The figure below sums up what appears to be going wrong.

 

A great all-in-one overview

If you only want to read one paper on serotonin and autism, and one that is not too science heavy, the one for you is:-

A review of the serotonintransporter and prenatal cortisol in the development of autism spectrum disorders

If you have more interest, then read on …

Research on Serotonin in the Autistic Brain

A recurring problem in all brain research is the lack of physical samples.  You cannot just open up someone's head and take a brain biopsy.  Research is either carried out on the tiny number of autistic brains donated to medical research, or it is non-invasive (MRIs and EEGs etc.), or it is very indirect.  An example of this latter type is the following paper from Belgium, home of kriek, a beer made from cherries and French fries served with mayonnaise.

Central serotonergic hypofunction in autism: results of the 5-hydroxy-tryptophan challenge test.

"Some studies have suggested that disorders in the central serotonergic function may play a role in the pathophysiology of autistic disorder. In order to assess the central serotonergic turnover in autism, this study examines the cortisol and prolactin responses to administration of L-5-hydroxy-tryptophan (5-HTP), the direct precursor of 5-HT in 18 male, post-pubertal, Caucasian autistic patients (age 13-19 y.; I.Q.>55) and 22 matched healthy volunteers. Serum cortisol and prolactin were determined 45 and 30 minutes before administration of 5-HTP (4 mg/kg in non enteric-coated tablets) or an identical placebo in a single blind order and, thereafter, every 30 minutes over a 3-hour period. The 5-HTP-induced increases in serum cortisol were significantly lower in autistic patients than in controls, whereas there were no significant differences in 5-HTP-induced prolactin responses between both study groups. In baseline conditions, no significant differences were found in serum cortisol and prolactin between autistic and normal children. The results suggest that autism is accompanied by a central serotonergic hypoactivity and that the latter could play a role in the pathophysiology of autism."

 

Tryptophan and DHEA

Just to complicate things a little further, I now introduce you to Tryptophan and DHEA.

Tryptophan is an essential amino acid, meaning that it is essential for human life, cannot be synthesized by the organism, and therefore must be part of your diet.

Tryptophan functions as a biochemical precursor for the following compounds:

• Serotonin, synthesized via tryptophan hydroxylase. Serotonin, in turn, can be converted to melatonin (a  neurohormone).
• Niacin is synthesized from tryptophan via kynurenine and quinolinic acids as key biosynthetic intermediates
• Auxin (a phytohormone) when sieve tube elements undergo apoptosis tryptophan is converted to auxins

The disorders fructose malabsorption and lactose intolerance cause improper absorption of tryptophan in the intestine, reduced levels of tryptophan in the blood and depression

What you will not find on Wikipedia, is that perhaps Tryptophan is in fact also a bona fide neurotransmitter in its own right.

Tryptophan as an evolutionarily conserved signal to brain serotonin: molecular evidence and psychiatric implications.

Abstract

The role of serotonin (5-HT) in psychopathology has been investigated for decades. Among others, symptoms of depression, panic, aggression and suicidality have been associated with serotonergic dysfunction. Here we summarize the evidence that low brain 5-HT signals a metabolic imbalance that is evolutionarily conserved and not specific for any specific psychiatric diagnosis. The synthesis and neuronal release of brain 5-HT depends on the concentration of free tryptophan in blood and brain because the affinity constant of neuronal tryptophan hydroxylase is in that concentration range. This relationship is evolutionarily conserved. Degradation of tryptophan, resulting in lower blood levels and impaired cerebral production and release of serotonin, is enhanced by inter alia inflammation, pregnancy and stress in all species investigated, including humans. Consequently, tryptophan may not only serve as a nutrient, but also as a bona fide signaling amino acid. Humans suffering from inflammatory and other somatic diseases accompanied by low tryptophan levels, exhibit disturbed social behaviour, increased irritability and lack of impulse control, rather than depression. Under particular circumstances, such behaviour may have survival value. Drugs that increase brain levels of serotonin may therefore be useful in a variety of psychiatric disorders and symptoms associated with low availability of tryptophan. 

This paper is open access, it gets quite technical but here is a summary of the conclusion. 

Decreased tryptophan metabolism in patients with autism spectrum disorders

 

Our findings support a possible mitochondrial dysfunction as a result of impaired tryptophan metabolism in cells from patients with ASDs

Although approximately 99% of the dietary tryptophan intake is metabolized via the kynurenine pathway, tryptophan is also the main precursor for both serotonin and melatonin

Melatonin plays a critical role in the regulation of the circadian rhythm, and anomalies of this rhythm have been associated with some of the signs in the autistic spectrum, like seizures or sleep disorders

Serotonin is a neurotransmitter involved in multiple aspects of brain functions, ranging from the regulation of mood to the control of appetite and social interactions and its production has been reported as deficient in ASD brains.

Tryptophan levels have been demonstrated to directly influence central nervous system (CNS) serotonin levels and behavior, and altered tryptophan transport has been described in fibroblasts from boys with attention deficit/hyperactivity disorder (ADHD)

Patients with ASDs, on average, are less capable of utilizing tryptophan as an energy source than controls.

Decreased tryptophan metabolism in patients with ASDs may alter metabolic pathways involved in the regulation of the early stages of brain development (first month of gestation), mitochondrial homeostasis and immune system activity in the brain.

Disruption of such pathways can primarily be caused either by insufficient serotonin production by placental cells, mitochondrial dysfunction and/or impaired balance between quinolinic and kynurenic acid in fetal cells. The combined effects of these events could lead to abnormal organization of neurons , particularly in specific brain regions, determining the imbalance between the short- and long-term circuitry that has been considered to be one of the fundamentals of the ASD neuropathology

Even though the ideal target tissue, brain, could not be investigated, our observation of decreased tryptophan metabolism in cells from patients with ASDs may provide a unifying model that could help explain the genetic heterogeneity of ASDs.

Tryptophan is a precursor of important compounds, such as serotonin, quinolinic acid, and kynurenic acid, which are involved in neurodevelopment and synaptogenesis. In addition, quinolinic acid is the structural precursor of NAD⁺, a critical energy carrier in mitochondria. Also, the serotonin branch of the tryptophan metabolic pathway generates NADH. Lastly, the levels of quinolinic and kynurenic acid are strongly influenced by the activity of the immune system. Therefore, decreased tryptophan metabolism may alter brain development, neuroimmune activity and mitochondrial function. Our finding of decreased tryptophan metabolism appears to provide a unifying biochemical basis for ASDs and perhaps an initial step in the development of a diagnostic assay for ASDs.

DHEA

DHEA  (didehydroepiandrosterone) It is the most abundant circulating steroid in humans, importantly for us to know it is also produced in the brain.  It has a variety of potential biological effects in its own right, binding to an array of nuclear and cell surface and acting as a neurosteroid.

Faulty serotonin--DHEA interactions in autism: results of the5-hydroxytryptophan challenge test. 

Abstract

BACKGROUND:

Autism is accompanied by peripheral and central disorders in the metabolism of serotonin (5-HT). The present study examines plasma dehydroepiandrosterone-sulphate (DHEA-S) and the cortisol/DHEA-S ratio following administration of L-5-hydroxytryptophan (5-HTP), the direct precursor of 5-HT, to autistic patients.

METHODS:

Plasma DHEA-S levels were determined both before and after administration of 5-HTP or placebo, on two consecutive days in a single blind order in 18 male autistic patients and 22 matched healthy controls.

RESULTS:

The 5-HTP-induced DHEA-S responses were significantly higher in autistic patients than in controls. In baseline conditions, the cortisol/DHEA-S ratio was significantly higher in autistic patients than in controls. Discussion: The results suggest that autism is accompanied by a major disequilibrium in the serotonergic system. The increased Cortisol (neurotoxic) versus DHEA-S (neuroprotective) ratio suggests that an increased neurotoxic potential occurs in autism.

CONCLUSIONS:

It is concluded that disequilibrium in the peripheral and central turnover of serotonin and an increased neurotoxic capacity by glucocorticoids are important pathways in autism.

 

Mice Studies

For the mice lovers amongst you, they also get their vitamin P (Prozac).

Serotonin Defects Identified in "Autistic" Mice

 

Serotonin modulators mitigate some BTBR behaviors

The researchers tested the effects of acute doses of fluoxetine (Prozac) (an SERT blocker), risperidone (a 5-HT_2A receptor antagonist), and buspirone (a partial 5-HT_1A receptor agonist) on social and repetitive behaviors of BTBR mice. These three compounds regulate serotonin activity and have inconsistent, limited, and sometimes harmful effects in rodent models of and people with autism. Only buspirone and fluoxetine were found to make BTBR mice significantly more social: treated mice spend proportionally more time socializing with a strange mouse than do saline-treated controls. Interestingly, BTBR mice treated with either buspirone or fluoxetine show a reduced interest in social novelty: when introduced to a second stranger mouse, they do not show a preference for either stranger. In contrast, the saline-treated controls spend more time investigating the newer mouse. Compared to either buspirone- or fluoxetine-treated mice and saline-treated controls, Risperidone-treated mice spend less time investigating strange mice and novel surroundings.

Regardless of treatment, BTBR mice spend comparable amounts of time burying marbles (an index of repetitive behavior). However, eliminating from the analysis one saline-treated control that did not bury any marbles suggests that risperidone-treated mice bury significantly fewer marbles than the saline-treated controls.

In summary, Daws and her team concluded that the autism-like behaviors of BTBR mice are likely due in part to an altered hippocampal SERT serotonin transporter and/or an altered 5-HT_1A serotonin receptor. These findings may lead to the identification of additional therapeutic targets for treating human autism.

 

Conclusion

There was a lot of science in this post and it was clear that the mechanisms involved are only very partially understood by researchers.

It is clear that interventions increasing central (brain) serotonin levels are likely to reduce autistic behaviours.  Prozac was mentioned, but there is a much wider class of drugs called serenic, many of which could potentially be helpful.  As mentioned earlier, the big problem with most of the drugs created for psychiatrists is side effects.  Autism is supposed to be very common, but you would not think so by looking at way new drugs are developed.  As a result, the drugs currently used in ASD and the majority of those in the pipeline are ones developed for other conditions (depression, bi-polar, psychosis , anxiety, ADHD, schizophrenia, Alzheimer’s etc.) many of which share some similar characteristics, but are essentially different conditions, with the exception of ADHD.  It is akin to trying to fix your Ford car with a parts bin filled with Toyota components; it is possible, but not a wise idea.

In my opinion, all the hormone dysfunctions in autism can eventually be traced back to damage caused by oxidative stress and neuroinflammation.  The brain has just adjusted to find a new homeostasis, which happens to be an autistic one.  The list of metabolic disturbances in autism is long and getting longer; but they are just consequences.  I very much doubt it is ever going to be possible to go hormone by hormone, neurotransmitter by neurotransmitter “correcting” them.   I think the best solution is to go further back up the chain and look at how hormones and neurotransmitters themselves are jointly regulated.  I do not believe anyone fully understands the molecular basis on which this is carried out, but as I have pointed out earlier in this blog, you can get the right answer for the wrong reasons and also without showing your workings.  As long as it works, perhaps understanding why does not matter.  A much less intellectual approach might indeed prove effective.

I will continue with my problem solving, but less intellectual, approach and see where it leads.

 
P.S.
 
Just to show how all the hormones are interrelated, I added the paper below from Japan.  They investigate the relationship between Oxytocin and Serotonin:

Evidence That Oxytocin Exerts Anxiolytic Effects via Oxytocin Receptor Expressed in Serotonergic Neurons in Mice

"It is thus possible that oxytocin modulates not only anxiety-related behavior but also social behavior via serotoninergic transmission. These observations may provide new insights into psychiatric disorders associated with disruptions in social and emotional behavior, including autism, anxiety disorders, and depression."

 

PolyPill for Autism - Part 2

In an earlier post I referred to polypills for autism. 

Polypill for Autism

These are one-size-fits-all pills that contain multiple drugs.  In theory they should be cheap and make it more likely that patients takes their medications.  It has been shown that the more pills you are on, the less likely it is you are to take them all.

The most popular application is heart disease, where the combination of a handful of drugs would extend many people's lives by several years.

In the UK such a pill has been launched and is, remarkably, available on-line.  It contains drugs that each have existing licences; but this polypill, as a combination, has not yet been licensed. 

Here is an except from PharmaTimes:-

The pill's four component medicines - the cholesterol buster simvastatin and blood pressure lowerers bendroflumethiazide, losartan and amlodipine - have each been licensed for individual use in the UK for many years, but the combination has not been cleared by any regulatory processes. 

This is because to obtain official approval through normal channels for the polypill as a preventative medicine is extremely complicated and "would take years and years", a spokesman for the programme told PharmaTimes UK News.

"You need randomised trials that demonstrate efficacy and safety for each component and in combination. It’s so difficult that for practical purposes it’s impossible,” Polypill patent owner Professor Sir Nicholas Wald, from the Wolfson Institute of Preventive Medicine at Queen Mary University of London, told the Financial Times.

However, the spokesperson confirmed to PharmaTimes that regulatory approval for the single pill is still being sought, "but we wanted to provide people with access to it in the meantime", he said. 

It is perfectly legal to sell the polypill because doctors are allowed to prescribe unlicensed drugs "off-label" where appropriate.

The unusual thing is that you get your consultation with a doctor on-line and for free.  Given how parents with kids with ASD struggle to access prescription medications for "off label" use, I found this interesting.
 
Here is the site:-

https://www.polypill.com/   

So when I finish my investigation into autism, in a few months time, maybe I will after all create the Peter Autism PollyPill, which will be a combination  of licensed drugs for "off label" application. 





 

Pregnenolone - an effective OTC anti-inflammatory therapy for autism?

Pregnenolone is the true mother hormone, being derived from cholesterol and the precursor of all steroid hormones. 

It is a potent anti-inflammatory agent.  It is  also claimed that supplementing with Pregnenolone will increase IGF-1, which I found interesting, given my very recent post on IGF-1 therapy in autism.  

In the late 1940’s and 1950’s successful studies were carried out into the use of Pregnenolone in the inflammatory condition of arthritis. 

As we found in recent posts regarding the vagus nerve, all inflammatory conditions (autism included) share much in common.  A treatment that is effective against neuroinflammation in one condition should be tested in the others.

Interest was high in Pregnenolone because it was cheap and free of troubling side effects.  Alternative steroid treatments, for example with Prednisone, can have major side effects.

In an earlier post I referred to the successful use of the steroid Prednisone in ASD in the US.  Wider adoption, and the lack of clinical trials, are held back by the fear of side effects.

Promoting Speech in a 7 year old Non-verbal Child with Autism

"... Dr Michael Chez, of the Pediatric Neurology and Autism Neurodevelopmental Program, Sutter Neuroscience Institute in Sacramento California.  He wrote a paper I have already referred to in this blog called:-

Immune Therapy in Autism: Historical Experience and Future Directions with Immunomodulatory Therapy

In that paper he talks of his knowledge of the effects of prednisone on children with autism and he mentions the dosage used.

Treatment was usually prescribed with daily prednisone doses of 2 mg/kg/day for 3 to 6 months. Limitations to therapy were usually Cushingoid side effects. As in other chronic conditions requiring steroids, pulse dosing was tried with steroids in the form of prednisone or prednisolone at 5 to 10 mg/kg twice per week.

Long-term success with no dependence or minimal Cushingoid effects has been noted in several hundred patients treated in this manner (Chez, unpublished data, personal communication).

In all, 17 of 32 patients showed response to prednisone after 2 to 4 months of treatment (53%). Improvements were seen on EEG and in language skills of the patients. Other steroid treatment series of regressed language in autistic spectrum patients diagnosed with LKS variant showed improved language with pulse-dose steroids."

 Pregnenolone Studies

Pregnenolone in the Treatment of Rheumatoid Arthritis

Pregnenolone in Rheumatoid Arthritis

If effect, Pregnenolone seems to be a weaker, but much safer, alternative to Prednisone.  Some people with arthritis currently take it. 

Pregnenolone is indeed already one of hundreds of fringe treatments for autism.  There are some very good reasons why it should be effective. 

Stanford University are currently running a clinical trial of Pregnenolone on adults with autism. It is the same researcher that worked on their study on NAC in children with autism.  It is nice to know that the adults with ASD have not been forgotten; after all, children have a habit of growing up.

A Study of Pregnenolone in the Treatment of Individuals With Autism

Conclusion

The next time I receive a question on this blog asking for a potentially effective OTC anti-neuroinflammatory “supplement” for autism, I will know what to suggest trying.

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:-

The polyvagal theory: phylogenetic substrates of a social nervous system (2001)

The Polyvagal Theory: phylogenetic contributions to social behavior (2003)

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

The vagus: A mediator of behavioural and visceral features associated with autism 

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:-

Cholinergic Activity in Autism: Abnormalities in the Cerebral Cortex and Basal Forebrain

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.


 

It’s a Small World – IGF-1 and NNZ-2566 in Autism

You may or may not believe in fate, but some strange things have been happening related to Australia, growth hormones and TBI.

Last week I took Monty, aged 10 with ASD, to have his IGF-1 (insulin-like growth factor) measured.  At the time, this had nothing to do with autism, rather just what the Endocrinologist had requested.  Then I start doing my research on hormones and autism and found, surprisingly, there is an ongoing clinical trial in autism using IGF-1.  Then I start looking again at TBI (Traumatic Brain Injury), which I see as having much in common with ASD.  I looked for similarities in hormone disruptions found in TBI and ASD; I found there are many and they are mainly related to GH (growth hormone) and IGF-1.  The problem with IGF-1 therapy is that it is intravenous; I had told the Endocrinologist that I was not going to measure IGF-1, because I was not very keen on giving Monty intravenous drugs.  In the end, I did the test anyway and I am glad I did.

As I researched TBI, I saw a great deal of interest in using GH as a therapy and the US military is providing a great deal of funding to develop therapies.

Today the postman brings me my first post from Australia in several years.  It contains some children books for Monty (Thank you Lisa).

Now I come across NNZ-2566;  it is a synthetic analogue of a naturally occurring neurotropic peptide derived from IGF-1.   NNZ-2566 is being developed both in intravenous and oral formulations for a range of acute and chronic conditions including TBI, Fragile X and Retts syndrome.  NNZ-2566 exhibits a wide range of important effects including inhibiting neuroinflammation, normalizing the role of microglia and correcting deficits in synaptic function.  NNZ-2566 is being developed guess where? Australia, by Neuren Pharmaceuticals.

Just 10 days ago the company made the following announcement:-

Melbourne, Australia, 18 October 2013: Neuren Pharmaceuticals (ASX: NEU) announced today that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation for Neuren’s programme to develop NNZ-2566 for Fragile X Syndrome. Fast Track designation is designed to expedite the development and review of important new medicines that are intended to treat serious diseases and meet unmet medical needs.

A different group of researchers are poised to begin clinical trials of IGF-1 in children with autism early next year. Because IGF-1 is already approved in the United States for use in children with short stature, the U.S. Food and Drug Administration is allowing the researchers to proceed directly to clinical trials for its use as an autism treatment.

What a lot of coincidences.

For those scientists among you, here are more details.

First of all it has been shown that in autism there are elevated levels of growth hormones.  Here is an American study.

Elevated levels of growth-related hormones in autism and autism spectrum disorder

 The Australians quote research from Finland that looks to me to contradict the above paper.  One difference is that the US researchers were testing blood and the Finns were testing spinal fluid.  What is clear is that in autism IGF-1 is not normal.

Neurotrophic Factors in the Pathogenesis of Rett Syndrome

Abstract

Rett syndrome is characterized by disruption of a period of vigorous brain growth with synapse development. Neurotrophic factors are important regulators of neuronal growth, differentiation, and survival during early brain development. The aims of this study were to study the role of neurotrophic factors in Rett syndrome, specifically whether Rett syndrome has abnormal levels of specific neurotrophic factors in serum and cerebrospinal fluid and whether the changes differ from other neuropediatric patients, for example, those with infantile autism. Four neurotrophic factors were measured: nerve growth factor, brain-derived neurotrophic factor, glial cell line—derived neurotrophic factor, and insulin-like growth factor 1 from the frozen cerebrospinal fluid and from serum (except glial cell line—derived neurotrophic factor) by enzyme-linked immunosorbent assay and cerebrospinal fluid glutamate and aspartate by high-performance liquid chromatography (HPLC) method in patients with Rett syndrome. Insulin-like growth factor 1 was measured from the cerebrospinal fluid of patients with infantile autism. We found low concentrations of cerebrospinal fluid nerve growth factor in patients with Rett syndrome compared with control patients. The serum levels and other cerebrospinal fluid neurotrophic factor levels of the patients did not differ from the controls. Patients with Rett syndrome had high cerebrospinal fluid glutamate levels. Patients with infantile autism had low cerebrospinal fluid insulin-like growth factor 1 levels. Nerve growth factor acts especially on cholinergic neurons of the basal forebrain, whereas insulin-like growth factor 1 acts on cerebellar neurons. In Rett syndrome, the forebrain is more severely affected than the other cortical areas. In autism, many studies show hippocampal or cerebellar pathology. Our findings are in agreement with the different morphologic and neurochemical findings (brain growth, affected brain areas, neurotransmitter metabolism) in the two syndromes. Impairment in dendritic development in Rett syndrome could be the consequence of cholinergic deficiency and of neurotrophic factor/glutamate imbalance. Cholinergic gene expression might be influenced by the Rett syndrome gene directly or via the neurotrophic factor system.

 Then we have research showing GH/IGF-1 has secondary functions beyond those in the text books.  Lots of nice words like neuroprotective, regenerative etc.

Role of the Growth Hormone/Insulin-Like GrowthFactor 1 Axis in Neurogenesis

Abstract

The growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis is not only involved in brain growth, development and myelination, but also in brain plasticity as indexed by neurogenesis. This may have links to various cognitive effects of GH and IGF-1. GH and IGF-1 affect the genesis of neurons, astrocytes, endothelial cells and oligodendrocytes. Specifically, IGF-1 increases progenitor cell proliferation and numbers of new neurons, oligodendrocytes, and blood vessels in the dentate gyrus of the hippocampus. In the adult cerebral cortex IGF-1 only affects oligodendrogenesis. Recently, GH therapy has also been shown to induce cell genesis in the adult brain. The profile of effects by GH therapy may be somewhat different than that of IGF-1. In addition, GH secretagogues (GHS) also have neuroprotective and cell regenerative effects per se in the brain. Finally, transgenic disruptions in GH signaling pathways affect neuron and astrocyte cell numbers during development and during adulthood. Altogether, data suggest that both exogenous and endogenous GH and/or IGF-1 may be used as agents to enhance cell genesis and neurogenesis in the adult brain. Theoretically these substances could be used to enhance recovery after brain injuries. However, further experiments with specific animal models for brain injuries are needed before clinical trials can be started. 

For those of you that like mice studies:

Growth factor improves autism symptoms in mice

Now back down under to let the Aussies make their case:

The Case for IGF-1 and IGF-1 (1-3) Glypromate in Autism

Courtesy of our friends “down under” you can read a presentation explaining the likely merits of both IGF-1 and its “terminal tripeptide” IGF-1 (1-3) as therapeutic agents in autism.  The clever Aussies have gone one better and produced NNZ-2566.  It is an analog of and IGF-1 (1-3).  This means it has that the molecule has been very slightly modified.  In this case this has been done to allow it to be orally available (i.e. not by injection) and to better cross the blood brain barrier (BBB). 

NNZ-2566 rationale for use in Autism Spectrum Disorders

Mount Sinai Hospital Clinical trial of IGF-1

Mount Sinai Hospital is a leading US teaching hospital in New York; they are carrying out a trial of IGF-1 in autism.  They are starting with a sub type with a genetic deficiency called SHANK3, but they will then look at the benefit in other types of ASD. 

http://clinicaltrials.gov/ct2/show/NCT01525901 

"In an important test of one of the first drugs to target core symptoms of autism, researchers at Mount Sinai School of Medicine are undertaking a pilot clinical trial to evaluate insulin-like growth factor (IGF-1) in children who have SHANK3 deficiency (also known as 22q13 Deletion Syndrome or Phelan-McDermid Syndrome), a known cause of autism spectrum disorder (ASD).

The seven-month study, which begins this month, will be conducted under the leadership of the Seaver Autism Center Clinical Director Alex Kolevzon, MD, and will utilize a double-blind, placebo-controlled crossover design in children ages 5 to 17 years old with SHANK3 deletions or mutations. Patients will receive three months of treatment with active medication or placebo, separated by a four-week washout period. Future trials are planned to explore the utility of IGF-1 in ASD without SHANK3 deficiency."

 

Conclusion

For a change, my conclusion is that further study is needed (by me).  Probably all the hormonal disruptions in autism need to be looked at together (serotonin, T3 etc) before any wild conclusions are drawn.