Hypothetical correspondence between activation of TRP channels, body surface temperature and evoked sensations. Upper part: Schematic representation of the thermal activation profile of various TRP channels when expressed in recombinant systems. All of them have been located in sensory neurons and/or skin cells. (Adapted from Patapoutian et al. 2003). Middle part: Schematic representation of impulse activity in various cutaneous sensory receptors during application to their receptive fields of temperatures indicated in the thermal scale. Lower part: Quality of sensations evoked in humans by application to the skin of different temperature values. Adapted from Von Frey.