Formaldehyde 4% solution

Ligand-activated Ca(2+)-permeable, nonselective cation channel involved in pain detection and possibly also in cold perception, oxygen concentration perception, cough, itch, and inner ear function .
PMID:17259981 PMID:21195050 PMID:21873995 PMID:23199233 PMID:25389312 PMID:33152265

Has a relatively high Ca(2+) selectivity, with a preference for divalent over monovalent cations (Ca(2+) > Ba(2+) > Mg(2+) > NH4(+) > Li(+) > K(+)), the influx of cation into the cytoplasm leads to membrane depolarization .
PMID:19202543 PMID:21195050
Has a central role in the pain response to endogenous inflammatory mediators, such as bradykinin and to a diverse array of irritants. Activated by a large variety of structurally unrelated electrophilic and non-electrophilic chemical compounds, such as allylthiocyanate (AITC) from mustard oil or wasabi, cinnamaldehyde, diallyl disulfide (DADS) from garlic, and acrolein, an environmental irritant .
PMID:20547126 PMID:25389312 PMID:27241698 PMID:30878828

Electrophilic ligands activate TRPA1 by interacting with critical N-terminal Cys residues in a covalent manner .
PMID:17164327 PMID:27241698 PMID:31866091 PMID:32641835

Non-electrophile agonists bind at distinct sites in the transmembrane domain to promote channel activation .
PMID:33152265
Also acts as an ionotropic cannabinoid receptor by being activated by delta(9)-tetrahydrocannabinol (THC), the psychoactive component of marijuana .
PMID:25389312
May be a component for the mechanosensitive transduction channel of hair cells in inner ear, thereby participating in the perception of sounds (By similarity)