Fig. 5. Intracellular recordings from a double opponent ganglion cell (G86R1C1). Upper trace: responses to a spot stimulus (radius, 
=600µm) at the centre of the receptive field are excitatory to ultraviolet (370nm), blue (450nm) and green (540nm) flashes and inhibitory to red (640nm) flashes. Lower trace: responses to an annulus (ext=1500mm, int=1050mm) reversed the excitation and inhibition seen at the centre, at all wavelengths. Note that at 540nm, where the crossover occurs, only transient responses, at the stimulus onset and offset, are reversed.
