Immune & Nervous Systems Interact
Twenty years ago, if someone had said that the nervous system and the immune system interfaced with one another I probably would have scoffed. I would have done so because with that era’s science I would have found it hard to conceive how brain and nerve cells could control individual immune cells and protein molecules and vice versa. Boy, I would have been very wrong.
With the sophisticated molecular biology developed over the past five years or so scientists have a new understanding of this interplay.
Our immune systems protect us from infections and work to heal damaged tissue after infection or injury. New science has come to realize that the nervous system and immune system work in concert to achieve these goals. Our sensory nerves detect injury, infection and inflammation which results in a signal of pain and/or itch. In fact, direct stimulation of peripheral sensory nerves can drive inflammatory changes in the skin.
Our immune cells have receptors for numerous neurotransmitters (chemicals released by nerve endings) that allow direct communication between the nervous and immune systems. And, as it turns out the immune cells can also produce neurotransmitters that communicate with nerve cells. Depending on which neurotransmitter is released it can either activate or suppress the immune response.
The immune to nerve communication can lead to a diverse array of unwanted symptoms: amplification of the itch sensation from eczema and hives, hyperresponsiveness of the airways in asthma, loss of sense of smell with nasal allergy and dysphagia (impaired nerve controlled esophageal motion) in eosinophilic esophagitis.
Now that this interplay is understood, scientists are busy doing research to find ways to modify things in a favorable way to better treat cancer, allergy, autoimmune diseases and infections.