Postembedding immunogold electron microscopy showing no accumulation of postsynaptic molecules required for GABAergic synapses on the AIS of PCs. A, B, GABAARα1. C, D, NL2. Immunogold particles for GABAARα1 and NL2 are localized in the postsynaptic membrane of symmetrical synapses on PC soma (So; A, C, filled arrowheads) but not on the AIS contacting BC axons (B, D, open arrowheads). Asterisks indicate profiles of BC axons. Scale bars, 250 nm.