Immune Cells – Friend or Foe?
Up until now, we have focused on the neurons, but they are just the conduit that transmit signals. The glia (part of the immune system) might be viewed as the brains of the operation. These highly evolved cells are in charge of keeping the neurons healthy and functioning properly. Whenever the glia get a whiff of injury, disease, malfunction, or some other threat to the integrity of the neuronal circuits, they rectify the situation … and pronto!
If a flu-like bug invades your body, the glia become activated and pump out viral-killing chemicals to eliminate the infectious threat. Although these chemicals are toxic to the neurons, the situation is short-term and necessary for the survival. As soon as the virus is destroyed and all the neurons are nurtured back to health, the glia return to their non-activated, “mellow” state.
In their mellow state, glia are always on the lookout for evidence of neuron malfunctions. In fact, neurons send out “find me” signals to the glia when injured or if they become overly activated. The glia rush to the site to engulf and remove injured cells. And, if the neurons are hyperactive, the glia surround the overworked neurons to get them to chill out (sort of like snuffing out a fire).
Within the CNS there are two main types of glia: microglia and astrocytes. If you think of these two cells as the neuron’s parents, the microglia play a more disciplinary role while the astrocytes are more nurturing. But all in all, they work as a team and their functions overlap.
The microglia move rapidly to the site of dying neurons or those that are injured. They prune and dissolve the nonfunctional portions, remove associated debris, and help the neurons heal. When neurotransmitter levels get out of hand (such as substance P and glutamate), it’s a sign of hyperactive neurons. The microglia isolate them (like putting the neurons in timeout) until they calm down.
The astrocytes play a key role in providing nutrients to your neurons, especially energy, as well as pulling glutamate out of the synapse. High glutamate levels are toxic to the neurons and if it persists for too long, it can trigger “cell death” signals. In fact, the astrocytes are the CNS cells responsible for maintaining a healthy glutamate/GABA balance. They also regulate brain blood flow.
Wait a minute. If the glia were doing their job, your CNS neurons would be calmly conveying information and the transmitter concentrations would be in the normal range. Could it be that your glia have gone rouge and are now your neurons’ foe? It appears so.
Brain imaging studies show fibromyalgia patients have chronically activated glia throughout their brains (this includes microglia and astrocytes). Also, the degree of activation, or what researchers call neuroinflammation, correlates with severity of pain, fatigue, and reduced physical function.
Commonly known triggers for initiating fibromyalgia can activate your glia (infection, trauma, stress, etc.). In addition, high levels of pain amplifiers (e.g., glutamate and substance P) will also agitate the glia, but why they remain “turned on” is probably tied to genetics. All in all, it appears that the glia are just as guilty as the neurons for causing fibromyalgia symptoms.
What can be done about activated glial cells? Naltrexone quiets them down (both the microglia and the astrocytes), but it also blocks the body’s opioid receptors. Therefore, low-dose naltrexone (LDN) is prescribed (typically 4.5 mg/day). Glia are quickly activated by chronic stress, so relieving stress should help as well. This includes gentle exercise, brisk walks, and forms of yoga that include relaxation breathing. In addition, a good night’s sleep is a great stressbuster.
If you are not familiar with LDN, AFSA funded a clinical trial that showed it benefited at least one-third of fibromyalgia patients. Details are in the Projects Funded section. AFSA also funded a 2019 study to document neuroinflammation in the brains of fibromyalgia patients. As for how to use LDN, see our article Giving LDN Your Best Shot.