TC synapses form normally in RIM-DKOSert. a–c, Ultrastructural analysis of the TC synapses. vGlut2 pre-embedding immunocytochemistry was performed and revealed with diaminobenzidine (a, b) or gold (c). In control (a) and RIM-DKOSert (b, c) mice, the terminal boutons are filled with synaptic vesicles and form asymmetric synapses that are frequently fenestrated (arrowheads). Scale bar: (in a) a–c, 500 μm.