▁responses , ▁signal ▁trans du ction ▁and ▁growth ▁control . ▁ ▁Rec ent ▁studies ▁indicate ▁that ▁TR PA 1 ▁is ▁activ ated ▁by ▁a ▁number ▁of ▁re active ▁ ▁( ally l ▁is oth i oc yan ate , ▁c inn am al de hy de , ▁far nes yl ▁th ios al icy lic ▁acid , ▁formal in , ▁hydro gen ▁per ox ide , ▁ 4 - h ydro x yn onen al , ▁ac role in , ▁and ▁te ar ▁g ases ) ▁and ▁non - re active ▁comp ounds ▁( nic ot ine , ▁P F - 4 8 4 0 1 5 4 ) ▁and ▁considered ▁as ▁a ▁" chem os ensor " ▁in ▁the ▁body . ▁TR PA 1 ▁is ▁co - ex pressed ▁with ▁TR P V 1 ▁on ▁n oc ice pt ive ▁primary ▁af fer ent ▁C - f ib ers ▁in ▁humans . ▁This ▁sub - pop ulation ▁of ▁peri pher al ▁C - f ib ers ▁is ▁considered ▁important ▁sens ors ▁of ▁n oc ice ption ▁in ▁humans ▁and ▁their ▁activation ▁will ▁under ▁normal ▁conditions ▁give ▁rise ▁to ▁pain . ▁Indeed , ▁TR PA 1 ▁is ▁considered ▁as ▁an ▁attract ive ▁ ▁pain ▁target . ▁TR PA 1 ▁knock out ▁m ice ▁showed ▁near ▁complete ▁at ten u ation ▁of ▁n oc if ensive ▁behav iors ▁to ▁formal in , ▁te ar - gas ▁and ▁other ▁re active ▁chemical s ▁. ▁TR PA 1 ▁ant agon ists ▁are ▁effective ▁in ▁blocking ▁pain