Hello Vic, and welcome.. Mestinon affects chemicals in the body that are involved in the communication between nerves and muscles. Mestinon helps to keep the chemical, acetylcholine, in the muscle synapse, just a little longer, so the message from the nerve can reach the receptors. I am not aware of any solid research that involves dopamine and pyridostigmine bromide (Mestinon). You'll find some good, simple information and visuals, on YouTube. There is some good information out there, re: muscarinic and nicotinic receptors.

It is said that Mestinon does not pass through the blood/brain barrier but the debate continues. Mestinon is not responsible for depression, problems with libido, mood changes, etc., nor is not responsible for weight gain.

http://www.youtube.com/watch?v=q5O1CRIc3B0