January 5, 2016
Autism Speaks recently posted an article titled "Evidence that brain-chemical imbalance drives autism symptoms" which discusses a new study published in the journal Current Biology: "Reduced GABAergic Action in the Autistic Brain". This is an important study as it is the first to demonstrate a link between severity of autistic symptoms and reduced action of the neurotransmitter GABA in humans. GABA is the primary inhibitory neurotransmitter and several studies have found strong evidence of its association with autism, one finding reduced GABA receptor subunits in post-mortem tissue of autistic brains, and another finding disrupted GABAergic signaling in mouse models of autism (references).
Typically a finding like this would not only help us develop new methods for treating individuals with the disorder in question, it could also help us understand what might be causing the disorder in the first place. One would hope that research efforts would be motivated by both of these goals.
The study’s lead author, Dr. Caroline Robertson, is quoted in the Autism Speaks article as saying “We want to see more research bridging the gap between animal and human research on autistic neurobiology, with the aim of developing new medications to ease symptoms in people disabled by the condition”.
One out of two is pretty good, at least in baseball.
If we were talking about any disorder other than autism, the next logical question the researchers -- and advocacy groups like Autism Speaks -- would be asking would be: “What could possibly cause this reduced GABA activity in the autistic brain”? If a researcher can suggest biologically plausible cause(s) that only servers to bolster their findings, and researchers do love to bolster their findings.
So why is there no discussion of what could possibly be causing this reduced GABA signaling in the autistic brain? Developing treatments for autism is a worthy goal, but shouldn’t we also be looking for ways to prevent new cases of autism?
Researchers and many advocacy groups like Autism Speaks cannot see the forest for the trees when it comes to discussing causes of autism, especially any possible association with vaccines.
Earth to Autism Speaks...mercury targets GABA receptors in the brain.
You know, mercury. Or more specifically, the ethylmercury which comprises roughly 50% of the preservative thimerosal which is still being injected in significant amounts into infants, children and pregnant women on a regular basis. There have been at least two studies showing that mercury interacts with GABA receptors (see here and here). Both studies looked at methylmercury and mercuric chloride, which does limit how their results can be interpreted for ethylmercury. Furthermore, the second study actually found conflicting results for the two compounds, showing that different mercury compounds can indeed have different effects.
So this begs the question, has ethylmercury itself been found to negatively impact GABA signaling? Why yes it has, see: Intermingled modulatory and neurotoxic effects of thimerosal and mercuric ions on electrophysiological responses to GABA and NMDA in hippocampal neurons.
"These data indicate that prolonged exposure of neurons to low micromolar THIM [thimerosal] concentrations significantly reduces both GABAergic and NMDA-evoked currents."
"We found that in control cultures, after 60-90 min exposure to the normal external solution, 18±2.5% of neurons (n=6 culture dishes tested) were classified as dead. Treatment with THIM for 60-90 min significantly increased the percentage of dead cells to 34±2.6 % for 1 μM THIM (n=6) and to 47±2.8% for 10 μM(n=6)."
The concentrations of thimerosal used in the study were quite high, but as the authors point out in the Discussion section:
"It needs to be emphasized, however, that mercurials supplied with vaccines accumulate in the brain tissue for several days (8) and it is likely that the effect reported here could appear at submicromolar THIM concentrations if administered for a prolonged time duration."
It seems reasonable to conclude that, at the very least, it is biologically plausible that the reduced GABA signaling found in the study described by Autism Speaks could be caused by exposure to mercury from vaccines, mercury amalgam, or the environment.
These researchers chose to avoid this information entirely. We have been seeing this for years, for example when the supposed “experts” ask what could possibly explain why boys are nearly 5 times more likely than girls to have autism? Of course it couldn’t have anything to do with the fact that the toxicity of mercury is synergistic with testosterone, whereas estrogen is actually protective against damage from mercury exposure. We’ve seen Dr. Eric Courchesne’s research, which found that brain volume in very young autistic individuals was larger. This finding has been replicated by multiple researchers, and has even been presented as “evidence” that autism is not an environmental insult, but rather a genetic disorder which children are born with. I suppose it is not at all relevant that this exact same finding has been found in a mouse model study and the cause was exposure to mercury.
For how long must we endure research like this which focus in on one particular aspect of autism, but refuses to look at the bigger picture because, as Wolfgang Ehrengut has so aptly said, “What must not be, cannot be”?