Touchy-feely protein sensors
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Discoveries of how cells detect temperature and touch at a molecular level explain how these stimuli are converted into nerve signals, enabling us to perceive and interact with the world around us
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1. Tactile stimuli 
Skin 
Stimulus
Epidermis
Dermis

2. Ion channel Protein connects Merkel cell to nerve fibre
Merkel cell
Nerve fibre

3. PIEZO protein
Nerve fibre
Blades curve out, creating bowl shape
Calcium ion- conducting pore is closed

4.Tactile stimulus
CA2+ions
Blades flatten out and open central pore
Ions flow to nerve fibre...
...electrical signal sent to brain

5. Temperature-sensitive proteins
Researchers use capsaicin component of chilli peppers and menthol to discover two
proteins that respond to heat and cold

TRPV1 Capsaicin- and heat-activated ion channel responds to temperatures above 40°C – close to pain threshold

TRPM8 Similar protein activated by temperatures below 28°C – cold threshold
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Sources: The Nobel Foundation, Reuters, Science News
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