Phototransduction in vertebrate rods: An example of the interaction of theory and experiment in neuroscience

A theoretical and experimental study of the response waveforms of vertebrate photoreceptors is presented. A model is described for the physical-chemical processes of light absorption, for the transconduction of the stimulus to a neural signal, and for the cellular system subserving these processes. Experimental tests are made of some of the theoretical implications and are shown to be consistent, one with the other. The role of the sodium pump in shaping the response waveform is considered, and the effects of light adaptation on response amplitude and kinetics are analyzed in terms of the internal transmitter hypothesis. Theory and experiment reveal gaps in one´s knowledge and point to needed future investigations.