Figure 4: Selective pre or postsynaptic manipulation of cholinergic signalling controls light responses. | Nature Communications

Figure 4: Selective pre or postsynaptic manipulation of cholinergic signalling controls light responses.

From: Dendro-dendritic cholinergic excitation controls dendritic spike initiation in retinal ganglion cells

Figure 4

(a) Blockade of acetylcholinesterase activity powerfully augments action potential (AP) firing evoked by preferred and null direction light bars (APs have been truncated for clarity). (b) Peri-stimulus histograms of light-evoked AP firing under the indicated conditions (ambenonium (ABN); bin size 20 μm). (c) Ambenonium augments pharmacologically isolated SAC-mediated excitatory PSPs (recorded in tetrodotoxin (TTX); 1 μM and GABAzine (10 μM)), but not inhibitory PSPs (recorded in TTX and mecamylamine (MMA); 10 μM). (d) Pooled data showing the selective augmentation of the area of excitatory PSPs by the blockade of acetylcholinesterase activity (area measured over a 100 ms time-window). (e) Blockade of the vesicular ACh transporter attenuates preferred direction light-evoked AP output, and unmasks null direction membrane hyperpolarization. (f) Peri-stimulus histograms of light-evoked AP firing under the indicated conditions (vesamicol (VES); bin size 20 μm). (g) Vesamicol attenuates pharmacologically isolated SAC-mediated excitatory PSPs, but not inhibitory PSPs. (h) Pooled data showing the selective reduction of excitatory PSPs by the pharmacological blockade of the vesicular ACh transporter (PSP amplitude has been normalized). All light stimuli were applied under photopic conditions. Stimulus intensity was twice that of background illumination. Data in d,h represent mean±s.e.m.

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