Figure 5From: Insulin Receptor Substrate 2 (IRS2)-Deficient Mice Show Sensorineural Hearing Loss That Is Delayed by Concomitant Protein Tyrosine Phosphatase 1B (PTP1B) Loss of FunctionCochlear ganglion and nerve fibers. (A–C) Cresyl violet staining of midmodiolar methacrylate sections of the cochlear ganglion at the cochlear basal turn in Irs2+/+Ptpn1+/+ (A), Irs2−/−Ptpn1+/+ (B) and Irs2−/−Ptpnr−/−mice (C) at postnatal wk 11. A slight reduction in the cellular density was more evident in both mutants (B, C) compared with wild-type (A). (D–F) Myelin P0 immunostaining of the cochlear ganglion shows less intense labeling in Irs2−/−Ptpn1+/+ (E) and Irs2−/−Ptpn1−/− (F) mice than in control mice (D). (G–I) Accordingly, myelin P0 immunostaining of nerve fibers projecting from the cochlear ganglion to the sensory cells is less intense in Irs2−/−Ptpn1+/+ and Irs2−/−Ptpn1−/− (arrows in H and I) than in wild-type mice (G). (J–L) Similarly, a weaker neurofilament 200-kDa immunostaining is observed in Irs2+/+Ptpn1−/− (K, white arrow) and Irs2−/−Ptpn1−/− (L, white arrow) mice compared with wild-type mice (J). Scale bars: A–I, 50 µm; J–L, 75 µm.Back to article page