Table 1.

ThermoTRP	Thermal activation	Chemical agonist	Sensory neuron/skin expression	Temperature phenotype of null mutant
TRPV1	> 42°C	capsaicin, acidic pH, camphor, ethanol, resiniferatoxin, 2-APB piperine, eugenol, gingerol, VaTx1-3 (spider toxin)	sensory neuron	impaired thermal avoidance and hyperalgesia
TRPV2	> 52°C	2-APB camphor, menthol, thymol, carvacrol, eugenol, 2-APB	sensory neuron	not reported
TRPV3	> 33°C		keratinocytes/sensory neuron?	impaired thermotaxis and thermal avoidance.
TRPV4	> 25–34°C	4αPDD, bisandrographolide	keratinocytes/sensory neuron	impaired thermotaxis, thermal avoidance, and hyperalgesia
TRPM2*	> 35°C	H2O2, ADP-ribose, βNAD	not reported	not reported
TRPM4*	heat**	cytosolic Ca2+	not reported	not reported
TRPM5*	heat**	cytosolic Ca2+	not reported	not reported
TRPM8	< 25°C	menthol, icilin, l-carvone eucalyptol, isopulegol, geraniol, linalool	sensory neuron	impaired cold sensation
TRPA1	< 17°C	cinnamaldehyde, mustard oil, eugenol, icilin, allicin, acrolein methyl salicylate, gingerol, GsMTx-4 (spider toxin), etc.	sensory neuron	- impaired cold sensation [5] - no thermal deficits observed [35]

^*TRPM2, TRPM4 and TRPM5 are temperature sensitive; however, evidence for their expression in DRG or skin is lacking [28,72]. The expression of TRPM5 in taste cells however suggests a potential explanation for the intriguing observation that temperature can affect taste perception [72].

^**Activity of TRPM4 and TRPM5 is increased by heating but thermal activation thresholds have not been determined.