Three Points of Contact

So are you feeling warm or cold?

Turns out, it's a complicated process…

Having come through the annual ritual of changing time and the following sense of sleep deprivation that results you may wonder in a daze why the transient receptor potential proteins (TRP) acquired another letter and a number in their “name” in earlier posts.

The two channels presented were TRPM8 and TRPV1, and they are members of two of three subfamilies we will examine in this and future posts. The subfamilies differ in their core structural organization as well as the way they bind chemicals. An example of the third subfamily is TRPA1, a channel often co-expressed in the same nerve cells as TRPV1.

Returning to an earlier post, and longer darker nights, the TRPM8 channel could be bound by a number of terpenes and some of these produced the sensation of being cold, while others did not produce a thermal sensation at all. This effect is also observed for TRPV1 which binds capsaicin, cannabidiol, and will also bind the terpene B-myrcene. When capsaicin binds the channel it fully dilates the channel and allows for movement of ions into or out of the nerve cell. When CBD binds the channel, it does not fully dilate the channel and ion transport does not occur.

To complicate matters further, when B-myrcene binds the channel it interferes with the ability of CBD to bind and produces a different physiological response than CBD alone. Something to keep in mind imbibing on the day of the green. All three compounds bind in different locations and do not compete for a binding site. Having covered all this, I feel a nap coming on. Until the next post.

Dr. Randal Stahl – Science Consultant