(A) The number of receptor SSDs, segmented from the combined receptor clusters of GABAARs and GlyRs, was decreased after 4-AP treatment (MW test, p < 0.0001). (B) This was mostly due to the loss of GABAAR SSDs that were segmented from the rendered images of GABAAR detections only (MW, ****p < 0.0001). (C) The number of GlyR SSDs (based on GlyR detections) were only marginally reduced (MW, **p < 0.01). Data information: Number of synapses: n = 452 in TTX, n = 583 in 4-AP condition, from three independent experiments. Mean ± SEM. 