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Monday 10 April 2017

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.








17 comments:

  1. Another big problem with mice is their behavior is not very human like, so trying to map mouse behaviors to human behaviors is problematic at best. Of course studies on higher level primates (like chimps) often take decades to complete and have big practical barriers when it comes to animal rights groups causing problems.

    The compromise seems to be rats as they are much more intelligent than mice and are omnivores like humans, not to mention they tend to be far more socially complex than mice.

    Nevertheless, rats are more expensive to maintain as they are much bigger than mice which is one reason they are not as popular. Plus, because there is so much previous investment in mouse lines, you are more likely to get your paper published as the editors of journals will be more knowledgeable of mouse research than rat research (leading to biases and network effects that help promote mouse research over rat research).

    Considering there is literally a very broad spectrum now in defining an autism diagnosis, it is also very challenging to apply that spectrum to mice when it comes to "autism" behavior just as it is a stretch of the imagination to say a mouse has had its intelligence improved if it performs better on the Morris Water Maze test (a test of memory and spatial reasoning) than a control and then map that gene to humans and say the same thing as the mouse might not have any memory problems, rather it has less motivation to complete the task. This is always the challenging thing with non-verbal kids as well is that you never know if they won't do something because of motivation, or because of some cognitive deficit because it is challenging for them to express complex emotions in the form of words. On top of that, what causes SIB-like symptoms in a mouse can be 180 degrees different than the many multiple causes of SIB in humans.

    So I don't see mice studies being useful for proving something in autism one way or another, rather because of their cheapness, efficiency, and short lifespan, they are very useful for giving researchers hints of where they should focus human research, or for us parents, areas of study we might want to think alternatively about, rather than merely wait around a decade or so for human studies that are likely to never get funded anyways, due to the severe costs associated with human trials and the dearth of funding for autism research.

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  2. Tyler, Iam planning to give my son ZMA but forgot the dose you suggested me, I wanted to do l aspartic acid but here ZMA is what I can get.The problem is that is in very low doses. Also wanted to know if BCAAs are dose dependant. I remember you were giving 14 grs a day. I am in 5 grs a day. Yesterday my son showed an incredible odd behaviour, he began to break all pages of one of his books and next, quickly looked for paper and pencil and started to write and draw many sheets, he told me he was working on his next movie.
    The new staff added is L serine and enalapril 5 mg. I don´t how to interpret this behavior, the lack of inhibition remains also, should I increase BCAAS and add ZMA?
    Valentina

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  3. L-Aspartic acid is just an amino acid, so I am surprised you can't get it in South America. Also, only issue with ZMA can be the zinc content which is high (which can be good or bad). By weight, most of ZMA is aspartate. On the label I have it is 450mg magnesium, 15 mg B-6, and 30mg zinc for a total of 495mg and each serving is 2.4g so that is 79.375% Aspartate by weight or 1.905g. Each serving is 3 capsules so to get at least 4grams of aspartate you need 7 capsules since each capsule will get you 635mg of aspartate. If you want to go up to 8 grams you would need 13 capsules per day (I would not go higher than that for an adult). Also, I was never giving 14g per day, rather I mentioned that a study looking at toxicity of aspartate suggested there were no amino acid imbalance problems in adult men up to 14 supplemental grams per day (you get a good amount of aspartate just through diet alone so this is via supplementation).

    As for BCAA's, they are not dose dependent. The effect is only temporary and your body is pretty stubborn about raising amino acid levels in the body beyond certain levels in a healthy person. Excess protein/aminos generally just gets processed by the liver back into glucose or else flushed out in the urine. The exact levels of tolerance are also going to be somewhat different from person to person based on age, size, sex, and genes.

    As for the behavior of your son, it sounds like basal ganglia issues (one of the core problems related to likely related to his dopamine issues). While there is no consensus on what the basal ganglia system does, the leading hypothesis with regards to behavior (especially motor behavior) is that it is responsible for selecting an appropriate action among a set of related actions and then inhibiting all of the other related actions so that when you want to kick a soccer ball, you don't instead start trying to brush your teeth. In a sense my best guess for your son's behavior was an extreme form of a tic, which is most famously associated with Tourette's syndrome where behaviors (especially motor and speech behaviors) occur which have no relevant context to the current situation. In simple terms it is a problem of behavioral inhibition. My son used to drink water out of dirty pools of water on the ground even though I had told him a million times not to, because he was unable to inhibit himself. He has not done that in quite a while, but that is an example of a very strange behavior few people can understand or even empathize with. The most simple behaviors seem to be programmed in a part of the midbrain called the

    https://en.wikipedia.org/wiki/Periaqueductal_gray

    It is thought that you have additional layers of complexity in behavior that are built upon modulating the PG via limbic areas (cingulate cortex, amygdala), and then more recently evolved cortical areas such as the frontal cortex. In fact, the most recently evolved area of the human brain (right smack in front of your head), when damaged can actually improve performance in some tasks because it is thought to be involved in task switching which is a capability you need if you are going to be able to multitask (people who have damage to this area will forget what they need to do to complete a current task if they get interrupted and have to do some other task).

    Also, keep in mind that people who do large amounts of dopaminergic affecting drugs like cocaine or methamphetamine will often display very strange behaviors as well, but people usually just shrug it off and say "he/she was just high on drugs", rather than saying "he/she really overloaded their D1 receptors causing them to become behaviorally disinhibited".

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    1. Tyler, your interpretation about possible Tourette makes me think it very seriously, as it appears about 10 or 11 age in kids with the autism profile of my son. To what you said about the odd behavior, I would add uncontrollably shouting curse words from time to time at home and in class,even though they are forbidden for him. May be a vocal tic that coincides with the lack of behavior inhibition.How would you treat mild Tourette? Enalapril could help with excess dopamine from what I understood. Don´t know if it is enough with BCAAs, I meant in the other mail 14gs of BCAAs. I think you told me that you do for your son 7 gr in the morning and 7 in the afternoon.
      Valentina

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  4. 'Ben-Ari has moved on to humans..' and so have we!

    Can't thank you enough Peter, for being our Pied Piper. I wanted to give an update on a couple of things. First, I go back to our ol' faithful Sytrinol. We recently moved and my husband has had severe allergies, where nothing OTC worked, ended up in ER and steroids. Only marginal control even with that. I was affected to a lesser extent. The one who held strong and steady through all this was my daughter. Clean and clear. I believe it is the Sytrinol. I think though that the antihistamine effect takes weeks to build up, because both my husband and I tried it with no effect. For my daughter it is a workhorse and definitely part of her 'polypill'.

    The second one is Diamox. I recently increased the dose to 125mg twice a day. Immediately, there has been a significant cognitive jump. This is long, so please bear with me. I am just thrilled and want to share. She was sitting next to another autistic boy, who suddenly turned towards her and tapped her arm. She immediately turned towards him and tapped his arm back and then turned away. After a few minutes, the boy tapped her again, and she tapped him right back. This was such an appropriate response from her, instead of cringing defensively or being passive. This exchange looked exactly like what children would normally do. There was also the briefest of pauses before she reacted and I could see that she deliberately thought about it. Another thing that happened was that her special needs music group had a performance before a very large audience, and all the other acts were by neurotypical groups. Instead of anxiety and irritability, she was thrilled to be on stage. Did well and afterwards nodded her head and said thank you when people praised her. It was a long route off the stage and out to the front, and all along the way, she kept turning left and right thanking people and once when someone just smiled but didn't say anything, she stopped and looked at them with anticipation, and they just smiled even more, so she said "thank you?" and finally got a "congratulations!" from them. She reminded me so much of a politician or a celebrity.

    Another change is that in the past if she misplaced something, she would come to us and say 'search' and get quite anxious and we would have to guide her and help her look. Over the weekend though, she couldn't find some toys, told us it was missing, that it was in the car, took the keys, went by herself, looked in front, and then to the back and got it. Not once did she ask for our help. Again, last night she wanted to lie down on the sofa to wind down before bed and she asked me for a blanket. I said it was upstairs and to go get it. There was no resistance from her side, no 'mummy, get it', etc, just went up, looked for it and got it.

    After all these years, I feel like her true character is emerging again. This is how she used to be before her regression, confident, take no nonsense, extroverted.

    The third thing I want to mention is a new probiotic we are trialling called Thrive. VSL3 we tried first, the GI benefit did not sustain and I saw nothing in other areas. Maybe even a little bit of irritability. So far, the labs for fecal O/P and fat have come back normal, so her doctor thinks it is dysbiosis. I will report back after a month of use.

    Oh, another big deal, she is now typing two words a minute, and at least some of the time looking at the screen. I set the font at 64pt. I discovered incidentally that its the Mac laptop keyboard that works best for her, rather than the iPad or the Mac desktop wireless keyboard. It is making a night and day difference. She is still very apraxic on the iPad.

    Again, many, many thanks Peter.

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    1. RG,
      When you first added Diamox you saw effects after how many days? Thank you.

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    2. When I first introduced Diamox last summer, it was soon after the addition of low dose clonazepam and potassium, so other than with epilepsy, it is difficult for me to delineate its effects from the others'. The effects were visible within days. There were many new things she did then. These three together improved her and our quality of life tremendously.

      This time, when I increased the dose, the effects were again visible within days. All the examples I mentioned in the previous comment were within a week.

      With epilepsy, the Diamox increased the seizure threshold, thereby eliminating the non catamenial ones we used to see with temperature differentials, hunger, etc. Since adding it, we have had only one tonic clonic, and it was the only one where she lost consciousness.

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  5. Peter, did you trial the intra nasal insulin?

    I also forgot to mention that with the increased Diamox, OCD is down about 75%.

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    1. RG, thanks for all the feedback. Would you like to document your experiences and results (good and bad) in a case history to be shared?

      I did make a trial of intra nasal insulin, just to see how it works and to see if there is some immediate wonderful effect. I did not make a serious trial for several weeks. I tried it on myself and you do notice you have taken it.

      There were no negative effects, but no immediate transformative positive effects. So a longer term trial would be needed.

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    2. Peter, are you creating a case history tab on your blog? Categorized by the intervention used or by autism sub type or age? I think this is an excellent idea. I would love to hear from more people using the micro dose of clonazepam. I have read in the comments (somewhere) you stated that in time, you use less and less of it. Why is this so? Is it because you are using it along with bumetanide?

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    3. Tanya, I am interested to collect case histories from people who have tried to treat autism using a scientific approach, not just things that I use. RG is unusual in trying off-label prescription drugs rather than just supplements.

      The effective dose of clonazepam does seem to decrease a little. I was using bumetanide already so that is not the explanation. I do not know the reason. In many cases of medication you have to increase dosage over time, which may eventually cause a problem. So it is good that such a tiny dose can have a positive effect.

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  6. Peter, I can get Diural, acetazolamide,the same as Diamox, do you think I could try it? Lowered valproate to 250 mg a day and he is taking enalapril 5 mg.
    Valentina

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    1. Valentina, I would first decide if enalapril is helpful. If it does not help then stop taking it. If you try different things at once you may not know what is helping and you increase the chance of negative interactions. Diamox does seem to help some types of autism.

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  7. Hi RG,
    Could you let me know the dosage of clonazepam and potassium?Where did you get clonazepam from?I am unable to get it anywhere in the uS without prescription
    Thanks
    SB

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    1. Most doctors will prescribe clonazepam for 1) seizures (short-term dosage if one has happened before) or 2) anxiety, making it much easier to get than eg verapamil (burinex/bumetanide readily available online pharmacies).

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  8. Hi SB,

    Clonazepam is .025mg. Its holding steady, I have not tried increasing it. My daughter is 110lbs. If we miss more than two days in a row, we see a difference. The very first thing I notice is an inability to sing aloud and control of diaphragm in general. Also, a reticence and hesitation in all things.

    Potassium is at 400mg once a day. Less is useless, has no effect. More makes her irritable and agitated. 400mg appears to be our sweet spot.

    Clonazepam is by prescription only and also a controlled drug. Our family doctor is very supportive and prescribes it for us. That said, recently, a couple of my friends also managed to convince their mainstream neurologists to prescribe it for their children. Which they now plan to crush up into micro doses. The other option, if possible, is to take a trip to Mexico and pick up all the medicines you need from there. On the California side, in Tijuana, there is a Costco where you can purchase everything needed, such as verapamil, bumetanide, diamox, clonazepam, etc. I think there is also a Walmart pharmacy. So no need to worry about fake products.

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