Fig. 1.

Immunolabeling of P2Y₂, P2Y₄, P2Y₆ and P2Y₁₂ receptors in the rat cochlea at E18. a P2Y₂ protein expression was detected in the intraganglionic spiral bundle (efferent fibers), but not in the spiral ganglion neurons. In addition, weak labeling was observed in the sensory epithelium (arrowhead) adjacent to the greater epithelial ridge. b P2Y₄ immunolabeling was only present on the sensory epithelium and greater epithelial ridge (arrowheads). c P2Y₆ immunolabeling was weak, but evenly distributed within the otocyst and the spiral ganglion. d P2Y₁₂ protein expression was constrained to the spiral ganglion neurons. Scale bars 50 µm. ger greater epithelial ridge, igsb intraganglionic spiral bundle, sgn spiral ganglion neurons