Simulated AMPAR activity using a model for GluR2. (A) Reaction scheme for AMPAR activation from Bartol et al. (2015). (B) Illustration of rod 1 spherule with BPs (purple and red), HCs (green and turquoise), and ribbon (semitransparent blue). AMPARs are shown as small white spheres. (C) Simulated single-vesicle AMPAR channel openings in four rod spherules compared with the average mEPSC recorded from mouse HCs (black trace ± SD). (D) Individual simulations run with four different seed values in rod 3 (colored traces). Superimposed on these traces is the average AMPAR activity observed with simulations in the corresponding sphere model (n = 25 seeds; black trace).