Low dose Clonazepam for MIA Autism, Ponstan and TRPM3 in Intellectual Disability, Clemastine to restore myelination in Pitt Hopkins, Improving Oxytocin therapy with Maca, Lamotrigine for some autism

 

Monty in Ginza, Tokyo

Today’s post comes from Tokyo and looks at 5 therapies already discussed in previous posts and follows up on recent coverage in the research. They all came up in recent conversations I have been having.

·      Low dose Clonazepam  – Maternal Immune Activation model of autism

·      Ponstan – TRPM3 causing intellectual disability  (ID/MR)

·      Clemastine – improving myelination in Pitt Hopkins syndrome model

·      Oxytocin – Maca supplement to boost effect

·      Lamotrigine (an anti-epilepsy drug) to moderate autism

The good news is that many of same therapies keep coming up.

Ponstan and TRPM3 caused ID/MR

There is a lot in this blog about improving cognition, which is how I called treating ID/MR.  There are very many causes of ID and some of them are treatable.

ID/MR was always a part of classic autism and in the new jargon is part of what they want to call profound autism.

I was recently sent a paper showing how the cheap pain reliever Ponstan blocks the TRMP3 channel and that this channel when mutated can lead to intellectual disability and epilepsy.

Mefenamic acid selectively inhibits TRPM3-mediated calcium entry.

My own research has established that mefenamic acid seems to improve speech and cognition, as well as sound sensitivity.  The latter effect I am putting down to its effect on potassium channels. 

De novo substitutions of TRPM3 cause intellectual disability and epilepsy

The developmental and epileptic encephalopathies (DEE) are a heterogeneous group of chronic encephalopathies frequently associated with rare de novo nonsynonymous coding variants in neuronally expressed genes. Here, we describe eight probands with a DEE phenotype comprising intellectual disability, epilepsy, and hypotonia. Exome trio analysis showed de novo variants in TRPM3, encoding a brain-expressed transient receptor potential channel, in each. Seven probands were identically heterozygous for a recurrent substitution, p.(Val837Met), in TRPM3’s S4–S5 linker region, a conserved domain proposed to undergo conformational change during gated channel opening. The eighth individual was heterozygous for a proline substitution, p.(Pro937Gln), at the boundary between TRPM3’s flexible pore-forming loop and an adjacent alpha-helix. General-population truncating variants and microdeletions occur throughout TRPM3, suggesting a pathomechanism other than simple haploinsufficiency. We conclude that de novo variants in TRPM3 are a cause of intellectual disability and epilepsy.

 

Fenamates as TRP channel blockers: mefenamic acid selectively blocks TRPM3

This study reveals that mefenamic acid selectively inhibits TRPM3-mediated calcium entry. This selectivity was further confirmed using insulin-secreting cells. K_ATP channel-dependent increases in cytosolic Ca²⁺ and insulin secretion were not blocked by mefenamic acid, but the selective stimulation of TRPM3-dependent Ca²⁺ entry and insulin secretion induced by pregnenolone sulphate were inhibited. However, the physiological regulator of TRPM3 in insulin-secreting cells remains to be elucidated, as well as the conditions under which the inhibition of TRPM3 can impair pancreatic β-cell function. Our results strongly suggest mefenamic acid is the most selective fenamate to interfere with TRPM3 function. 

Here, we examined the inhibitory effect of several available fenamates (DCDPC, flufenamic acid, mefenamic acid, meclofenamic acid, niflumic acid, S645648, tolfenamic acid) on the TRPM3 and TRPV4 channels using fluorescence-based FLIPR Ca²⁺ measurements. To further substantiate the selectivity, we tested the potencies of these fenamates on two other TRP channels from different subfamilies, TRPC6 and TRPM2. In addition, single-cell Ca²⁺ imaging, whole-cell voltage clamp and insulin secretion experiments revealed mefenamic acid as a selective blocker of TRPM3.

  

Oxytocin

 Oxytocin does increase how emotional you feel; the difficulty is how to administer it in a way that provides a long lasting effect.  The half-life of oxytocin is a just minutes. The traditional method uses a nose spray.

I favour the use of a gut bacteria that stimulates the release of oxytocin in the brain.  The effect should be much longer lasting. Even then the effect is more cute than dramatic.

The supplement Maca does not itself produce oxytocin, but “it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways”.

So Maca looks like an interesting potential add-on therapy to boost the effect of oxytocin.

One reader wrote to me with a positive report on using Maca by itself, without any oxytocin.

 

Oral Supplementation with Maca Improves Social Recognition Deficits in the Valproic Acid Animal Model of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a congenital, lifelong neurodevelopmental disorder whose main symptom is impaired social communication and interaction. However, no drug can treat social deficits in patients with ASD, and treatments to alleviate social behavioral deficits are sorely needed. Here, we examined the effect of oral supplementation of maca (Lepidium meyenii) on social deficits of in utero-exposed valproic acid (VPA) mice, widely used as an ASD model. Although maca is widely consumed as a fertility enhancer and aphrodisiac, it possesses multiple beneficial activities. Additionally, it benefits learning and memory in experimental animal models. Therefore, the effect of maca supplementation on the social behavioral deficit of VPA mice was assessed using a social interaction test, a three-stage open field test, and a five-trial social memory test. The oral supplementation of maca attenuated social interaction behavior deficit and social memory impairment. The number of c-Fos-positive cells and the percentage of c-Fos-positive oxytocin neurons increased in supraoptic and paraventricular neurons of maca-treated VPA mice. These results reveal for the first time that maca is beneficial to social memory and that it restores social recognition impairments by augmenting the oxytocinergic neuronal pathways, which play an essential role in diverse social behaviors.

Maca (Lepidium meyenii) belongs to the cruciferous family and grows at high altitudes in Peru. In 2002, it was transplanted from Peru to the Yunnan Province of China. It is rich in dietary fiber; has many essential amino acids and nutrients including vitamin C, copper, and iron; and its root contains bioactive compounds. It is globally consumed and is popularly used as a fertility enhancer and aphrodisiac. On the other hand, with its potential to possess multi-nutritious components, it is reported to have diverse functions, including immunomodulation, antioxidant, antidepressant, antirheumatic, UV radiation protection, hepatoprotective, anti-fatigue, and neuroprotective effects. Interestingly, although the mechanism of the neuronal effect of maca is unclear, the uptake of maca extract improves learning and memory in memory-impaired model mice induced by either ethanol, ovariectomy, or scopolamine. However, the effects of maca on social memory impairment in neurodevelopmental disorders, including ASD, have not yet been tested.

In this study, the effects of maca on ASD animal models, in utero VPA-exposed mice, were investigated. The effect on social recognition by maca uptake with gavage was assessed using the social interaction test, a three-stage open field test, and the five-trail social recognition test. We also explored whether maca intake affects oxytocinergic signaling pathways, which play an important role in various social behaviors.

In this study, we showed that maca uptake rescues the deficits of social behavior and social recognition memory in VPA mice, a mouse model of autism. The c-Fos immunoreactivity of oxytocinergic neurons in SON and PVN increased significantly after maca treatment in VPA mice. Following previous studies indicating that OT administration ameliorates the impairment of social behavior in VPA mice, maca may also have improving effects on the deficit of social behavior and social recognition memory of VPA mice, probably by activating the OT neuronal pathway. Previous studies showed that maca could improve cognitive function in the mice model of impaired cognitive memory induced by either ovariectomy, ethanol, or scopolamine. Further studies are necessary to elucidate the potential link between maca and OT and to determine which components are involved in improving social recognition memory.

We have shown that maca improves the impairment of social memory and social behavioral deficits through oxytocinergic system modulation in this study. Although maca may not have an immediate effect on social behavioral deficits and takes days or weeks to demonstrate the effects, behavioral improvements, were visible regardless of the time of oral intake. The time between the very last oral intake of maca and the start of the social behavioral experiments in this study was more than 16 h. The duration of the maca’s effect on social behavioral deficits after the supplementation period is being investigated in our follow-up experiments. The possibility of the persistent effect of maca is very appealing, given that OT does not have a sustained effect due to its rapid metabolism, despite its immediate effects. Therefore, taking maca as a supplement while also receiving repeated OT treatment may have a synergistic, sustainable effect on improving social impairment in patients with ASD. Maca is already being used as a dietary supplement worldwide and has a high potential for practical applications.

 

This study showed for the first time that maca supplementation improves the impairment of social recognition memory in ASD model mice. We added the mechanism that social memory improvement may occur through the upregulation of oxytocinergic pathways. Maca highlights the possibility of treating social deficits sustainably in individuals with ASDs.

 

Low dose clonazepam

Professor Catterall was the brains behind low dose clonazepam for mice, I just translated it across to humans. It is one way to modify the E/I (excitatory/inhibitory) imbalance in autism.

I found that it gave a boost to cognition. Not as big as bumetanide, but worth having nonetheless.

I do not believe you have to be a bumetanide responder to respond well to low dose clonazepam.

Several people have written to me recently to say it works for their child.

Our reader Tanya is interested in the Maternal Immune Activation (MIA) trigger to autism. She highlighted a recent study showing how and why clonazepam can reverse autism in the MIA mouse model of autism. 

Clonazepam attenuates neurobehavioral abnormalities in offspring exposed to maternal immune activation by enhancing GABAergic neurotransmission

Ample evidence indicates that maternal immune activation (MIA) during gestation is linked to an increased risk for neurodevelopmental and psychiatric disorders, such as autism spectrum disorder (ASD), anxiety and depression, in offspring. However, the underlying mechanism for such a link remains largely elusive. Here, we performed RNA sequencing (RNA-seq) to examine the transcriptional profiles changes in mice in response to MIA and identified that the expression of Scn1a gene, encoding the pore-forming α-subunit of the brain voltage-gated sodium channel type-1 (Na_V1.1) primarily in fast-spiking inhibitory interneurons, was significantly decreased in the medial prefrontal cortex (mPFC) of juvenile offspring after MIA. Moreover, diminished excitatory drive onto interneurons causes reduction of spontaneous gamma-aminobutyric acid (GABA)ergic neurotransmission in the mPFC of MIA offspring, leading to hyperactivity in this brain region. Remarkably, treatment with low-dose benzodiazepines clonazepam, an agonist of GABA_A receptors, completely prevented the behavioral abnormalities, including stereotypies, social deficits, anxiety- and depression-like behavior, via increasing inhibitory neurotransmission as well as decreasing neural activity in the mPFC of MIA offspring. Our results demonstrate that decreased expression of Na_V1.1 in the mPFC leads to abnormalities in maternal inflammation-related behaviors and provides a potential therapeutic strategy for the abnormal behavioral phenotypes observed in the offspring exposed to MIA.

 

Pitt Hopkins – Clemastine and Sobetirome

Poor myelination is a feature of much autism and is a known problem in Pitt Hopkins syndrome.

I did cover a paper a while back where the Pitt Hopkins researchers showed that genes involved in myelination are down-regulated not only in Pitt Hopkins, but in several other popular models of autism.

From the multiple sclerosis (MS) research we have assembled a long list of therapies to improve different processes involved in myelination. Today we can add to that list sobetirome (and the related Sob-AM2). Sobetirome shares some of its effects with thyroid hormone (TH), it is a thyroid hormone receptor isoform beta-1 (THRβ-1) liver-selective analog.

Some people do use thyroid hormones to treat autism, and indeed US psychiatrists have long used T3 to treat depression.

The problem with giving T3 or T4 hormones is that it has body-wide effects and if you give too much the thyroid gland will just produce less.

One proposed mechanism I wrote about long ago is central hypothyroidism, that is a lack of the active T3 hormone just within the brain. One possible cause proposed was that oxidative stress reduces the enzyme D2 that is used to convert circulating prohormone T4 to T3. The result is that your blood test says your thyoid function is great, but in your brain you lack T3.

It looks like using sobetirome you can spice up myelination in the brain, without causing any negative effects to your thyroid gland.

Rather surprisingly, sobetirome is already sold as a supplement, but it is not cheap like Clemastine, the other drug used in the successful study below.

 

Promyelinating drugs promote functional recovery in an autism spectrum disorder mouse model of Pitt–Hopkins syndrome

Pitt–Hopkins syndrome is an autism spectrum disorder caused by autosomal dominant mutations in the human transcription factor 4 gene (TCF4). One pathobiological process caused by murine Tcf4 mutation is a cell autonomous reduction in oligodendrocytes and myelination. In this study, we show that the promyelinating compounds, clemastine, sobetirome and Sob-AM2 are effective at restoring myelination defects in a Pitt–Hopkins syndrome mouse model. In vitro, clemastine treatment reduced excess oligodendrocyte precursor cells and normalized oligodendrocyte density. In vivo, 2-week intraperitoneal administration of clemastine also normalized oligodendrocyte precursor cell and oligodendrocyte density in the cortex of Tcf4 mutant mice and appeared to increase the number of axons undergoing myelination, as EM imaging of the corpus callosum showed a significant increase in the proportion of uncompacted myelin and an overall reduction in the g-ratio. Importantly, this treatment paradigm resulted in functional rescue by improving electrophysiology and behaviour. To confirm behavioural rescue was achieved via enhancing myelination, we show that treatment with the thyroid hormone receptor agonist sobetirome or its brain penetrating prodrug Sob-AM2, was also effective at normalizing oligodendrocyte precursor cell and oligodendrocyte densities and behaviour in the Pitt–Hopkins syndrome mouse model. Together, these results provide preclinical evidence that promyelinating therapies may be beneficial in Pitt–Hopkins syndrome and potentially other neurodevelopmental disorders characterized by dysmyelination.

 

Sobetirome  (also called GC-1)

Sobetirome is a thyroid hormone receptor isoform beta-1 (THRβ-1) liver-selective analog.

In humans, sobetirome lowers plasma LDL cholesterol and reduced plasma triglycerides, while its liver-selective activity helped avoid the side effects seen with many other thyromimetic agents.

 

Myelin repair stimulated by CNS-selective thyroid hormone action

Oligodendrocyte processes wrap axons to form neuroprotective myelin sheaths, and damage to myelin in disorders, such as multiple sclerosis (MS), leads to neurodegeneration and disability. There are currently no approved treatments for MS that stimulate myelin repair. During development, thyroid hormone (TH) promotes myelination through enhancing oligodendrocyte differentiation; however, TH itself is unsuitable as a remyelination therapy due to adverse systemic effects. This problem is overcome with selective TH agonists, sobetirome and a CNS-selective prodrug of sobetirome called Sob-AM2. We show here that TH and sobetirome stimulated remyelination in standard gliotoxin models of demyelination. We then utilized a genetic mouse model of demyelination and remyelination, in which we employed motor function tests, histology, and MRI to demonstrate that chronic treatment with sobetirome or Sob-AM2 leads to significant improvement in both clinical signs and remyelination. In contrast, chronic treatment with TH in this model inhibited the endogenous myelin repair and exacerbated disease. These results support the clinical investigation of selective CNS-penetrating TH agonists, but not TH, for myelin repair.

 

Compound protects myelin, nerve fibers

 

Research could be important in treating, preventing progression of multiple sclerosis, other neurodegenerative diseases

A compound appears to protect nerve fibers and the fatty sheath, called myelin, that covers nerve cells in the brain and spinal cord. The new research in a mouse model advances earlier work to develop the compound - known as sobetirome - that has already showed promise in stimulating the repair of myelin.

Lead author Priya Chaudhary, M.D., assistant professor of neurology in the OHSU School of Medicine who is focused on developing therapies for neurodegenerative diseases, said that the technique is a common step in drug discovery.

"It is important to show the effectiveness of potential drugs in a model that is most commonly used for developing new therapies," Chaudhary said.

The researchers discovered that they were able to prevent damage to myelin and nerve fibers from occurring, by stimulating a protective response in the cells that make and maintain myelin. They also reduced the activity of migroglia, a type of inflammatory cell in the brain and spinal cord that's involved in causing damage in multiple sclerosis and other diseases.

"The effects are impressive and are at least in part consistent with a neuroprotective effect with particular inhibition of myelin and axon degeneration, and oligodendrocyte loss," the authors write.

The discovery, if proven in clinical trials involving people, could be especially useful for people who are diagnosed with multiple sclerosis early in the disease's progression.

"The drug could protect the nervous system from damage and reduce the severity of the disease," Bourdette said.

 

Does Lamotrigine have the potential to 'cure' Autism?

Recently headlines appeared like this one:-

Scientists 'CURE autism' in mice using $3 epilepsy drug

It referred to the use of the epilepsy drug Lamotrigine to treat a mouse model of autism, caused by reduced expression of the gene MYT1L.

What the tabloid journalists failed to notice was that there has already been a human trial of Lamotrigine in autism.  That trial was viewed as unsuccessful by the clinicians, although the parents did not agree.

There were many comments in the media from parents whose child already takes this drug for their epilepsy and they saw no reduction in autism. There were some who found it made autism worse.

 

MYT1L haploinsufficiency in human neurons and mice causes autism-associated phenotypes that can be reversed by genetic and pharmacologic intervention

 

Lamotrigine therapy for autistic disorder: a randomized, double-blind, placebo-controlled trial

In autism, glutamate may be increased or its receptors up-regulated as part of an excitotoxic process that damages neural networks and subsequently contributes to behavioral and cognitive deficits seen in the disorder. This was a double-blind, placebo-controlled, parallel group study of lamotrigine, an agent that modulates glutamate release. Twenty-eight children (27 boys) ages 3 to 11 years (M = 5.8) with a primary diagnosis of autistic disorder received either placebo or lamotrigine twice daily. In children on lamotrigine, the drug was titrated upward over 8 weeks to reach a mean maintenance dose of 5.0 mg/kg per day. This dose was then maintained for 4 weeks. Following maintenance evaluations, the drug was tapered down over 2 weeks. The trial ended with a 4-week drug-free period. Outcome measures included improvements in severity and behavioral features of autistic disorder (stereotypies, lethargy, irritability, hyperactivity, emotional reciprocity, sharing pleasures) and improvements in language and communication, socialization, and daily living skills noted after 12 weeks (the end of a 4-week maintenance phase). We did not find any significant differences in improvements between lamotrigine or placebo groups on the Autism Behavior Checklist, the Aberrant Behavior Checklist, the Vineland Adaptive Behavior scales, the PL-ADOS, or the CARS. Parent rating scales showed marked improvements, presumably due to expectations of benefits.

One reader of this blog who heard all about the news and was sceptical, since after all it is a mouse model. Her 8 year old non-verbal child was not happy taking the drug Keppra and was already scheduled to try Lamotrigine. 

“Within a week his teacher called to say he was saying his ABCs, the next week he was counting out loud, the following month he’s attempting to repeat words of interest and this week he’s spelling animals by memory, dolphin, duck, wolf, chicken, pig, etc.

We are 2 months in and at 50mg, our target dose is 100mg bid. Obviously with our success, I’ve been working with his doctor and will continue to.”

 

Conclusion

Even though every day new autism research is published, there is so much already in this blog that not much appearing is totally new to regular readers.

We saw several years ago that low dose clonazepam should be beneficial to some people with autism, in particular Dravet syndrome. Today we learnt a little more about why Nav1.1 might be disturbed beyond those with Dravet syndrome. In the maternal immune activation model it seems to be a winner. It seems to benefit many of those who have trialed it.

Treating myelination deficits has been well covered in this blog. In previous posts we saw how Pitt Hopkins syndrome researchers showed how myelination gene expression was disturbed in a wide range of autisms. Today we saw evidence to support such therapy and we discovered a new drug.

Oxytocin does help some people with autism, but not as much as you might expect. Today we learnt of a potential add on therapy, a supplement called Maca.

The idea that anti-epilepsy drugs might help some autism has been well covered. From low dose valproate to low dose phenytoin from Dr Philip Bird in Australia.

Treatment of Autism with low-dose Phenytoin, yet another AED

Recent research suggested that Lamotrigine should help some with autism and today you learned that it really does help in one case. The fact that a tiny study a few years ago suggested no responders just tells us that only a small subgroup are likely to benefit.

We already know that some people's autism is made worse by their epilepsy therapy. This is just what you would expect. Time to find a different epilepsy therapy.

My favorite new therapy, low dose mefenemic acid / ponstan has numerous effects. One reader without autism, but with an unusual visual dysfunction (visual snow syndrome) and a sound sensitivity problem contacted me a while to see if NKCC1 might be the root of his problem. I suggested he try Ponstan, which did actually work for him and is easy to buy where he lives. Now he sends me research into all its possible modes of action. One mode of action relates to a cause of intellectual disability (ID/MR). Is this a factor in why Ponstan seems to improve speech and cognition in some autism? I really don't mind why it works - I just got lucky again, that is how I look at it. The more I read the luckier I seem to get.

Mouse Models of Autism

Researchers use animals in place of humans, for research purposes; in the case of autism it is usually the unfortunate mouse, but sometimes rats. 

The Jackson Laboratory in the US is the source for more than 8,000 strains of genetically defined mice used for research purposes.   

SFARIgene has a fascinating on-line database  that lists all the mouse/rat models of autism and the research linked to them. Most importantly it also lists all the “rescue lines”, the research showing therapies that improved the mouse’s autism. 

For example, you can look up the model of human Fragile-X, which is called Fmr1, and then see the long list of drugs that helped that particular type of mouse. 

There are already well over 200 different mouse/rat genetic models of autism and 1,000 rescue lines.  

So while medicine has no approved drugs to treat human autism, autistic mice appear to be better placed.

There remains the question of how close humans are to mice.  They are more closely related than you might think, but there are still big differences. 

There are also induced models of autism, where the scientists have not tinkered with a specific single gene; these might closer relate to most human autism. You will find a model of advanced paternal age, a model of diesel exhaust particles, and all kinds of other things. 

One very widely used model is called the Maternal Immune Activation (MIA) model.  In the research you may find it called Polyinosinic:polycytidylic acid, or just poly(I:C).

 In the MIA model the pregnant mouse is injected will an immune stimulant (Polyinosinic:polycytidylic acid) that triggers a big immune response, which affects the development of her pup.  The pup is born with features that resemble human autism. 

There is a similar model where the mother is given an infection rather than induced inflammation. 

Depending on the gestational age at which MIA or infection is administered, the offspring can be studied in the context not only of autism, but also schizophrenia.  This should not be surprising if you have read the post discussing the overlapping polygenic nature of autism and schizophrenia. 

You can even induce temporary autism using proprionic acid.  Proprioic acid is produced naturally in your intestines when the food you eat reacts with the bacteria that live there.  Proprionic acid is a SCFA (short chained fatty acid), you need to have some SCFAs, but as it often the case, too much may not be good for you.  In the case of a mouse, when injected with a large dose of poprionic acid, its behaviour changes to that of autism.  This is entirely reversible over time, or faster still, by administering the antioxidant NAC (N-acetyl cysteine). 

Researchers create a mouse model that matches as closely as possible the human condition they are trying to treat. Then they can investigate various drugs that might be of therapeutic benefit.  In some cases a large number of drugs from a library of compounds are tried on the off chance of stumbling upon one that is effective. 

An alternative approach is when a researcher has a theory that a specific drug should be effective, he then tests it in several different mouse models of autism.  If the drug is effective in several mouse models that would suggest it might be beneficial in some humans. This is how Ben-Ari advanced his bumetanide research and Catterall his low dose Clonazepam research; the difference is that Ben-Ari has moved on to humans, as regular readers know.  

Those of you who look at the SFARgene database will see how hundreds of so very different things, both genetic or environmental, lead to the same autism.

The Brain is Hypothermic in Mitochondrial Disease, but is it in Autism?

Having noted in the previous post something as simple, and measurable, as reduced blood flow in the brain exists in autism, I decided to dig a little deeper.

Not only can you measure blood flow in specific regions of the brain, but using Magnetic Resonance Spectroscopy you can measure the temperature of the brain.

Intense heat production is an essential feature of normal brain energetics; most of the energy used for brain functioning is eventually released as heat.  In the brain, heat is produced mostly by mitochondrial oxidative chemical reactions. Most of the energy required for brain activity is generated from the net chemical reaction of oxygen and glucose; some of this energy (33%) is immediately dissipated into heat, and the rest (67%) is used to synthesize ATP. The final ATP hydrolysis releases part of the energy back to the system as heat.

Note that your core temperature is not the same as your brain temperature.

Brain temperature T_br should be near constant

Increases in Cerebral Blood Flow reduce T_br and increases in brain metabolism increase T_br.

Neuronal activity is temperature dependent, with neuronal firing increasing with increased temperature.  Many other functions in the brain are temperature dependent.

When your brain gets too hot febrile seizures can be the result, caused by excessive neuronal firing.

Mitochondrial Disease

Since heat in the brain is produced mostly by mitochondrial oxidative chemical reactions, when mitochondrial disease is present, it would be expected that there would be less heat and therefore a lower Brain temperature T_br.  This time biology is indeed logical and this is the case.  People with mitochondrial disease have measurably colder brains.

The brain is hypothermic in patients with mitochondrial diseases

We sought to study brain temperature in patients with mitochondrial diseases in different functional states compared with healthy participants. Brain temperature and mitochondrial function were monitored in the visual cortex and the centrum semiovale at rest and during and after visual stimulation in seven individuals with mitochondrial diseases (n=5 with mitochondrial DNA mutations and n=2 with nuclear DNA mutations) and in 14 age- and sex-matched healthy control participants using a combined approach of visual stimulation, proton magnetic resonance spectroscopy (MRS), and phosphorus MRS. Brain temperature in control participants exhibited small changes during visual stimulation and a consistent increase, together with an increase in high-energy phosphate content, after visual stimulation. Brain temperature was persistently lower in individuals with mitochondrial diseases than in healthy participants at rest, during activation, and during recovery, without significant changes from one state to another and with a decrease in the high-energy phosphate content. The lowest brain temperature was observed in the patient with the most deranged mitochondrial function. In patients with mitochondrial diseases, the brain is hypothermic because of malfunctioning oxidative phosphorylation. Neuronal activity is reduced at rest, during physiologic brain stimulation, and after stimulation.

The question is whether this lower brain temperature, in itself, leads to changes in brain function/performance and hence mood, behaviours and cognition.

Mitochondrial Disease in Autism

There are various types of mitochondrial disorder in autism and, confusingly, different terminology is used for similar biological conditions.  Regressive autism triggered by a viral illness, fever, or in some cases a reaction to a vaccine is likely mitochondria-related.

I have covered Dr Kelley from Johns Hopkins ideas on this subject, but there are others.  Here are some other perspectives:-

Has Your Child with Autistic Symptoms Been Properly Screened for a Subset of  Mitochondrial Disease Known as OXPHOS?

Mitochondrial dysfunction in autism spectrum disorders: a systematic review and meta-analysis

Fever Effect in Autism

It is well documented that in many people with autism their symptoms subside when they are sick and have a fever.  This is the so-called “fever effect”.  It only applies to some people with autism and in a small number the effect can be dramatic.

There are numerous unproven theories.

A Study of Behaviors Associated with Fever in Children with Autism/PDD

Hyperthermia and the amelioration of autism symptoms 

  

Hyperthermia and the Improvement of Autism Spectrum Disorder (ASD) Symptoms

Background:  The observation that some ASD patients manifest clinical improvement in response to fever suggests that symptoms may be modulated by immune-inflammatory factors.  The febrile hypothesis of ASD stems from this observation, and could be due to (1) the direct effect of temperature; (2) a resulting change in the immune inflammatory system function associated with the infection of fever; and/or (3) an increase in the functionality of a previously dysfunctional locus coeruleus-noradrenergic (LC-NA) system.  

Objectives:  To assess the effect of hyperthermia on ASD symptoms.

Methods:  We completed a double blind crossover study of 15 children with ASD (5 to 17 years) using two treatment conditions, hyperthermia condition (102°F) and control condition (98°F) in a HydroWorx aquatic therapy pool.  Five children with ASD without fever response acted as controls, completing only the hyperthermia condition, to ensure safety and feasibility.  Safety measures and Social Responsiveness Scale (SRS) were collected.  Ten patients with ASD and history of fever response were enrolled and received both treatment conditions.  Vital signs, temperature monitoring and clinical observations were completed throughout their time in the pool.  Parents completed the SRS and RBS-R.  Pupillometry biomarker and buccal swabs for DNA and RNA extraction were collected pre and post pool entry. 

Results:  Ten subjects with ASD and a history of fever response were enrolled and completed the hyperthermia condition (102°F) and control condition (98°F) at the aquatic therapy pool.  Improvement during the hyperthermia condition (102°F) was observed in social cognition, using the Social Responsiveness Scale (SRS) total raw score (p = 0.0430) and the SRS Social Behavior subscale raw scores (p = 0.0750); repetitive behaviors, using the Repetitive Behavior Scale-Revised (RBS; p =0.0603) and the SRS Restricted and Repetitive Behavior subscale (p = 0.0146); and on global improvement, using the Clinical Global Impression Scale-Improvement (CGI-I; p=0.0070). 

Conclusions:  This study demonstrates the feasibility of observing the direct effect of temperature in children with ASD, both with and without a history of febrile response, and provides preliminary data on the relationship between body temperature and changes in social and behavioral measures. It explores the direct effects of temperature on ASD symptoms, and offers a window into understanding mechanisms involved in improvement in ASD symptoms during fever episodes.  Behavior changes observed for each child were similar to those observed by parents during febrile episodes, including increased cooperation, communication and social reciprocity and decreased hyperactivity and inappropriate vocalizations. This study is important for the development of translational models on the mechanism of symptom improvement and the identification of novel targets for therapeutic development.

Why not measure Brain temperature T_br in a large number of people with Autism?

The above study at the “Albert Einstein” medical school involved putting people in hot tubs to warm them up and then measuring their autistic symptoms. You would have thought it would have occurred to them to quickly pop upstairs to the MRI to measure brain temperature T_br.  I do not think you need to be an Einstein to think of that.

Perhaps the people that exhibit the fever effect are the ones with low brain temperature T_br ?  That would seem well worth checking.

It also is logical to just warm up the part of the body that will affect behaviour.

Hypothermia in Mouse Models

If you look up hypothermia and autism you again encounter Robert Naviaux, from University of California San Diego, and not much else.  Naviaux is a very clever researcher, but more importantly he just does not give up.  He is doggedly pursuing his antipurinergic therapy for autism.

It turns out that hypothermia is a feature of the maternal immune activation (MIA) mouse model of autism that he is using in his research.

Indeed his antipurinergic therapy corrects this hypothermia.

From:-

Antipurinergic therapy corrects the autism-like features in the poly(IC) mouse model.

Relative hypothermia is a long-term feature of the Poly(IC) MIA Model. This is the lower line (PICSAL), when treated with Suramin, you get the yellow line PICSUR, with a higher body temperature similar to that of the regular mice (blue lines)  When they gave Suramin to regular mice (dark blue line) the was no overall change in body temperature.

So we know that in at least one major mouse model of autism, hypothermia is known feature.  Did anyone measure it in the others?

Conclusion

If raising T_br improves autism symptoms so much, in some people, then why not just figure out a clever way to increase it?

Raising blood flow apparently should lower T_br.

There are likely numerous options like increasing the oxygen level in the blood, which might be expected to increase heat production, for example using Diamox (Acetazolamid). 

Reducing heat loss by wearing a wooly hat, should marginally raise brain temperature, unless the brain then compensates for this.

Since the illicit drug MDMA, or ecstasy, is already known to raise brain temperature, there probably are ways to develop a safe drug therapy to achieve a small increase in brain temperature.  

  

Hopefully Naviaux will find a safe antipurinergic therapy, which might also be used in people with low T_br, as well as broader autism.