Close appositions between RtST boutons and PrIN neurons were considered contacts. Data from a dSTAG animal. RtST (green) and PrIN (red) channels (a–d). The arrows point to BDA-stained RtST boutons on a z-stacked image (a). RtST collateral (b) and PrIN soma (c) ± 1 z-step of each other. Combining the channels reveals a contact between a RtST bouton and PrIN dendrite (d). 1 z-step = 0.76 μm. Scale = 20 μm.