Sections through the organ of Corti (A, B) and the spiral ganglion (SG) (C, D) of the rat.A, Section hybridized with DIG-labeled δ2 antisense riboprobe showing no specific staining. B,C, D, Sections hybridized with DIG-labeled δ1 antisense riboprobe. In B (basal turn), the IHCs display an intense hybridization signal. No hybridization signal is seen in the OHCs, Deiters cells (DCs), Claudius cells (CCs), or the tectorial membrane (TM). In C(second turn) and D (apical turn), type I (large arrows) and putative type II (arrowheads) neurons and satellite glial cells (small arrows) express the δ1 mRNA at high levels. Scale bars: A,B, 50 μm; C, 100 μm;D, 10 μm.