Figure 5: Cholinergic signalling controls the stimulus sensitivity and dynamic range of ON-DSGCs.

(a,b) Antagonism of nAChRs (hexamethonium (Hex); red symbols and traces) attenuates action potential (AP) firing evoked by preferred direction light bars moved across the receptive field over a wide-range of speeds (a), and at the optimal speed across a range of light intensities (b; speed=0.24 mm/s). (c) Impact of cholinergic signalling on the computation of direction selectivity, and preferred direction light-evoked AP firing over the stimulus range shown in a,b. Note the decreased stimulus sensitivity, attenuation of AP firing rate, but preservation of directional tuning in hexamethonium. All light stimuli were applied under photopic conditions. Stimulus intensity is relative to background illumination.