Thermoreceptors in human skin signal the central nervous system that a change in environmental temperature has occurred. What is the likeliest way such thermoreceptors create a receptor potential?

1. A plasma membrane ion channel protein changes shape.
2. The Q10¬ effect will cause all reactions inside the receptor cell to go faster.
3. The receptor cell will swell as it warms up.
4. Particles of radiant energy bind to receptor proteins in the cell.