For example, in the visual system, sensory cells called rod and cone cells in the retina change the physical energy of light signals into electrical impulses that travel to the brain. The light causes a change in a protein called rhodopsin. In mammalian examples, more light hitting the receptor results in the transduction of a signal into fewer electrical impulses. In invertebrates, however, more rhodopsin activation results in increased frequency of neuron firing.
Related pages[change | change source]