I wrote here a few weeks ago on treatment approaches for chemical sensitivity. This article will dig a little deeper into what happens in your brain when you’re exposed to chemicals.

Neurophysiology 101: the NMDA Receptors

Your body is full of chemical messengers, and receptors that can receive them. In your brain, the messengers are called neurotransmitters (as in, transmitters in the brain. Hence the name.) Some of the best known neurotransmitters are serotonin (of SSRI fame—or infamy), dopamine (the “pleasure and reward” neurotransmitter), and acetylcholine (generally most associated with memory, but also associated with things like muscle movement.) Each of these has its own type of receptor, which can accurately decode its message.

The NMDA receptor actually has two different types of neurotransmitters that it deals with: Glutamate, the neurotransmitter that stimulates it, and glycine, the neurotransmitter that calms it down. (You might recognize glutamate from MSG, aka Monosodium Glutamate.)

What does it mean when the receptor is stimulated versus calmed down, you ask? Stimulation causes a calcium channel to open, while calming it down closes the calcium channel. Calcium in this case is carrying an electrical charge… so think of it like a bolt of electricity.

Chemical Exposure and NMDA Receptors

This interesting study shows that rat exposure to DDT (a nasty insecticide) leads to damage to the rat’s retinal NMDA receptors, causing them to remain perpetually open and leading to cell death. However, introduction of antioxidant support counteracts this effect.

Other chemicals that stimulate the NMDA receptors include formaldehyde, organophosphate pesticides, the solvent toluene, and carbon monoxide.

If you’re wondering where you might be exposed to these chemicals:

  • Formaldehyde (aka formalin, formal and methyl aldehyde): used as a disinfectant and preservative, it’s a suspected carcinogen (especially linked with lung cancer).  Exposure in high doses can cause asthma, headaches, eye irritation and upper respiratory irritation (I can attest to this firsthand from anatomy lab).
  • Organophosphate pesticides: These are some of the most common pesticides in use today, and they are neurotoxic to insects. Unfortunately they’re neurotoxic to us as well. For that reason, OP use has been banned in most residential areas, but they’re still commonly used on fruits and veggies, and are also used in plastics and as solvents. They’ve been linked with low testosterone and thyroid disruption. Avoid them by buying the Dirty Dozen fruits and veggies organic.
  • DDT is a common insecticide. You can avoid it by buying the Dirty Dozen fruits and veggies organic.
  • Toluene: found in paint and paint thinners, perfumes, nailpolish, and in cigarette smoke.
  • Carbon Monoxide: found in cigarette smoke, leaky furnaces and heaters, and anything fueled by propane.

What Does Excitotoxicity Look Like?

The short answer is, Multiple Chemical Sensitivity: getting sick from slight chemical exposures.

Perpetually stimulated NMDA receptors also set off a biochemical cascade which ultimately results in production of a chemical called peroxynitrite, which can damage your mitochondria. The mitochondria are the energy powerhouse of your cells, producing ATP, which is your body’s energy currency. Damaged mitochondria usually leads to chronic fatigue, muscle weakness, migraines, intolerance of exercise, and general inflammation.

Other more chronic conditions with a possible connection to prolonged excitotoxicity include Multiple Sclerosis, Alzheimer’s Disease, ALS, and Parkinson’s Disease.

The Good News

Studies show 1, 2, 3 that antioxidant support helps to calm down the inflammatory response of excitotoxicity. 

As mentioned in this article on chemical sensitivity treatment, the very best way to support this process is with glutathione, the most powerful antioxidant in the body. There are multiple delivery methods, including nebulized, intranasal, or oral liposomal (meaning it’s essentially emulsified in fat so you can absorb it).

It’s also necessary to make sure you have adequate micronutrient cofactors to help regenerate glutathione and the enzymes it works with. I highly recommend individualized micronutrient testing.