The TRPA family is comprised of only one mammalian member, the TRPA1 (formerly named ANKTM1). TRPA1 is expressed in peripheral sensory neurons, where it is suggested to contribute to the detection of painful stimuli.¹

Originally, it was thought that TRPA channels sensed painfully cold temperatures,² but a more conservative description is that TRPA1 is sensitive to membrane/cytoskeletal perturbations caused by low temperatures^3-5 and perhaps stretch.⁶ In addition, it is sensitive to pungent natural compounds present in cinnamon oil, mustard oil, and wintergreen oil.

TRPA1 is also expressed in hair cells, where its role in sensing mechanical forces is still unclear and controversial.¹

TRPA1 has a similar structure to all other TRP ion channels; six transmembrane domains, intracellular N-and C-terminus. However, the N-terminal domain possesses 17 ankyrin repeats that might indicate its potential role as a mechanosensor.^6,7

In addition, TRPA1 is expressed in nociceptive neurons expressing TRPV1 and might serve as a marker for polymodal nociceptors.⁸