<P> In physiology, sensory transduction is the conversion of a sensory stimulus from one form to another . </P> <P> Transduction in the nervous system typically refers to stimulus alerting events wherein a physical stimulus is converted into an action potential, which is transmitted along axons towards the central nervous system where it is integrated . </P> <P> A receptor cell converts the energy in a stimulus into a change in the electrical potential across its membrane . It causes the depolarization of the membrane to allow the action potential to be transduced to the brain for integration . </P> <P> In the visual system, sensory cells called rod and cone cells in the retina convert the physical energy of light signals into electrical impulses that travel to the brain . The light causes a conformational change in a protein called rhodopsin . This conformational change sets in motion a series of molecular events that result in a reduction of the electrochemical gradient of the photoreceptor . The decrease in the electrochemical gradient causes a reduction in the electrical signals going to the brain . Thus, in this example, more light hitting the photoreceptor results in the transduction of a signal into fewer electrical impulses, effectively communicating that stimulus to the brain . A change in neurotransmitter release is mediated through a second messenger system . Note that the change in neurotransmitter release is by rods . Because of the change, a change in light intensity causes the response of the rods to be much slower than expected (for a process associated with the nervous system). </P>

Transduction occurs for the visual system in the and for the auditory system in the