You may have heard of Dopamine, but you know it's effect very well if you have not heard of it. It is a simple organic chemical that plays an important physiological role in the bodies of animals. Dopamine control reward driven learning and is basically a feel good chemical. It has important roles in a long list of acts that are controled by the frontal lobe;
This may look like a list of the items that are often dysregulated in autism also, funny how that lines up.
Now Dopamine cannot naturally cross the Blood Brain Barrier (BBB) so the effects to learning are not
normally seen, but activated mast cells in the brain or the breaching of the BBB will effect this very quickly. This is symptomatic of regressive autism when a child withdraws suddenly and stops learning, of course this effect in regressive autism is often made worse by casomorphin that get into the brain once the BBB is breached.