Environmental factors	Receptors	Role in sensing	References
Visible radiation	RHO	Light and dark	Tsutsumi et al., 2009a
	OPN1LW	Red-green light	Tsutsumi et al., 2009a
	OPN1MW	Blue light	Tsutsumi et al., 2009a
Electric potential	L-type VGCC	Electric potential	Denda et al., 2006
Magnetic field	Unknown	Magnetic energy	Lisi et al., 2006
High-frequency sound	Unknown	10 - 30 kHz sound	Denda & Nakatani, 2010
Temperature	TRPV1	Temperature > 43˚C	Tsutsumi et al., 2011b
		Capsaicin, low pH < 6.6	Inoue et al., 2002
	TRPV2	Temperature > 52˚C	Tsutsumi et al., 2011b
	TRPV3	Temperature > 33˚C	Peier et al., 2002
		Thymol, eugenol	Xu et al., 2006
	TRPV4	Temperature > 34˚C	Chung et al., 2003
		Osmotic pressure	Liedtke, 2007
	TRPM8	Temperature < 22˚C	Tsutsumi et al., 2010a
		Menthol	Denda et al., 2010
	TRPA1	Temperature < 17˚C	Tsutsumi et al., 2010a
Atmospheric pressure	Unknown	Changes of pressure	Ikeyama et al., 2013
Mechanical stress	Unknown	Touch	Tsutsumi et al., 2009b
Oxygen	Unknown	Oxygen partial pressure	Boutin et al., 2008
Perfume	OR2AT4	Sandalwood	Busse et al., 2014