English: Sensory stimuli are transduced into action potentials by sensory nerves. At rest, membrane channels maintain a negative electric potential across the plasma membrane (left). Sensory nerves express membrane channels that respond to touch, heat, cold or various chemical stimuli. Upon stimulation, these channels depolarize the plasma membrane (middle). When membrane depolarization reaches a certain threshold, voltage-gated sodium channels open and generate an action potential which propagates along the nerve (right).