Why Are More Males Affected With Autism?

There is also this from the brilliant, Dr. Russell Blaylock……

“One of the enigmas of autism is why it occurs in males more often than females. Actually there are a number of toxins that have this gender selectivity. Studies have shown, for example, that both mercury and monosodium glutamate (MSG) have greater neurotoxicity in males than females. The reason appears to be the enhancing effect of testosterone on both substances’ toxicity. Glutamate is the most abundant neurotransmitter in the brain and operates through a very complex series of receptors (3 major inotropic receptors- NMDA, AMPA and kainite receptors, and 8 metabotropic receptors). As stated, the presence of glutamate outside brain neurons, even in very small concentrations, is brain cell toxic. Because of this, the brain is equipped with a very elaborate series of mechanisms to remove glutamate quickly, primarily by utilizing glutamate uptake proteins (EAAT1-5). Mercury, aluminum, free radicals, lipid peroxidation products and inflammatory cytokines can easily damage these. One of the important ways glutamate regulates neuron function is by allowing calcium to enter the cell and by the release of calcium within cell storage depots. When calcium (glutamate operated) channels are opened, the calcium flows in as a wave of concentrated calcium. These are referred to a calcium waves or oscillations. They regulate a number of neuron functions, one of which plays a vital role in brain development. During brain development, the future neurons are lined up along membranes within the core of the undeveloped brain. These cells must migrate outwardly to reach their final destination and they do so by guided chemical signals mainly released by microglia and astrocytes. These trillions of connections also develop during a process called synaptogeneis, and use many of the same signals.
Studies have shown that the calcium waves cause developing brain cells to migrate, which is essential for development of the brain (it forms the architectonic structures and functional columns of the brain). Interestingly, testosterone also affects embryonic brain cell migration by regulating calcium waves, and mercury, probably by stimulating glutamate release, does the same thing. Estrogen reduces calcium oscillations and stops the migration. Other chemical signals in the brain also play a role (reelin).  If calcium oscillations are not properly regulated, that is- there are too many calcium oscillations, the brain develops abnormally. Testosterone and glutamate have an additive effect on these calcium waves. In this way, testosterone enhances the damaging effect of excessive glutamate and mercury. Studies have shown that higher doses of MSG during brain formation can cause abnormalities of brain development that closely resemble mercury poisoning and the toxic effects of high levels of inflammatory cytokines. Interestingly, vaccination has been shown to significantly increase the toxicity of several other neurotoxins, so much so that they can trigger brain cell destruction or synaptic loss even when subtoxic concentrations of the toxicants are used. Testosterone aggravates this toxicity as well.
Studies of autistic children show an elevated level of androgens in most, even in female autistic children. In general, androgens, such as testosterone, enhance neurological injury and estrogens tend to be protective of the brain.” http://www.russellblaylockmd.com/