Quote
The Alfa-1-receptors stimulate the conversion of liver molecules to sugar molecules (glucogenolysis), resulting in more glucose in the blood. Alpha-1 also stimulates the consumption of oxygen (O2) by the cells and stimulates the conversion of fatty acid in blood to energy. All of these alpha-1 items result in more energy for the person. If the alpha-1 receptors are clogged (e.g. by a pesky heavy metal molecule), one would feel fatigued. The following things can clog NA alpha-1 receptors: antagonist drugs, lead, mercury, cadmium, sulfur-toxins, over 70,000 manmade chemicals, and several natural toxins.


From: http://www.beatcfsandfms.org/html/BrainChem.html

There's some research here: http://www.beatcfsandfms.org/references/StudiesOnReceptors.html but no actual links to the articles. I may look them up at university at some point. There doesn't seem to be any research into mercury specifically targetting the noradrenaline alpha-1 receptors, like there is in regards to the GABA receptors, so I don't know where he's got his information from. But needless to say mercury affects the receptors in the brain, and most sufferers suffer from fatigue and even cronic fatigue.