So imagine you’re experiencing a lot of stress, not hydrating and not eating well – sound familiar? Your muscles (especially neck muscles) get tight, and this hypertonicity triggers the TRPV1 channels to send a signal to adjust osmotic pressure, leading to salt excretion. This lowers the salt concentration outside the cells and the cell shrinkage can be corrected. This hormone causes more water to be retained and more salt to be excreted. TRPV1 sense cell shrinkage and signals the hypothalamus of the brain to release a hormone called vasopressin (also called ADH). TRPV1 sense osmotic changes, specifically hypertonicity. A 2010 paper shows that there is a TRPV1 in the brain that does not react to heat or capsaicin, but does respond to osmotic stress. So it’s interesting that TRPV1 channels are also involved in regulation of osmotic pressure. This swelling occurs from changes in osmotic pressure in the brain, which in turn causes impingemenet on the innervated tissues of the meninges surrounding the brain. Migraineurs will be familiar with the sensation of brain swelling during migraine. Researchers who injected capsaicin into the carotid artery caused a significant increase in jugular CGRP levels. Capsaicin, on the other hand, increases sensitivity to CGRP via activation of the TRPV1 channels – ie, it is a TRPV1 and CGRP agonist, not antagonist. The new CGRP receptor antagonist drugs aim to blunt the receptivity of the neurons to this peptide. CGRP is a neuropeptide in the brain that causes blood vessel dilation and migraine at elevated levels. You may have heard about the new generation of calcitonin gene-related peptide(CGRP) inhibiting drugs out there (shots like Aimovig). The activation of TRPV1 causes a release of CGRP from the trigeminal nerves, followed by inflammation within the meninges (the tissue surrounding the brain). The anti-migraine drug sumatriptan was recently shown to block trigeminal TRPV1 channels. TRPV1 channels have been shown to be involved in the pathophysiology of migraine. That lends an additional layer of insight to my theories around why acidic foods trigger migraine.) TRPV1 channels, CGRP, and migraine
(As an aside: it’s interesting to note that TRPV1 channels are activated by pH changes. ( Source)Ĭapsaicin, as it turns out, is such a strong agonist (amplifier) of TRP channels that it is frequently used in science to study these channels, although there are multiple TRP channels, with capsaicin acting primarily on the vanilloid receptor-1 (VR-1) of the TRP channel (also known as TRPV1). They also mediate local responses like blood flow, cough, histamine & hormone release. Sensations include: pain, heat, coolness, taste, nausea, cough and pheromones. They dictate quality of life and allow us to navigate through our environment. The sensations under their control are important to daily function. TRPs are your chemical radar system used to detect friends and foes. This is achieved through the same super family of receptors called TRPs. There is an underlying system, the equivalent of a chemical radar system that allows us to navigate the world, warning us of problems & invaders, as well as reminding us of friends and the familiar. TRP channels are ion channels located on the plasma membrane of cells that help the body to sense and respond to it’s environment. It’s quite incredible that the body is able to sense heat and cold even in the absence of actual heat and cold, through molecules like capsaicin or (for cold) menthol that act on cells via something called TRP channels. Capsaicin and TRP channelsĬapsaicin is the molecule in pungent, spicy foods that gives it the burning sensation of hot on the tongue. Today I want to focus on chili and the main compound that gives it its spicy (and headachey) kick – capsaicin. It took me years to solve the mystery of these two issues: copper and chili. Yet spicy food has been the biggest migraine trigger for me historically, enough so that I still choose to avoid spicy food during my moon-time to avoid brain fog even now that my chronic migraine pattern is resolved. Another irony is that I grew up a few miles from the famous Hatch Chile fields of southwestern New Mexico. One irony is that I grew up in a part of the world rich in copper, home to some of the world’s largest copper mines – but copper deficiency was playing a big role in my migraine pattern. There are two big ironies in my journey healing migraine.