Heterogeneity of phospholipase C in the cochlea of the guinea pig

In the present study, we investigated the presence of phosphatidylinositol-specific phospholipase C (PLC) isoforms in the cochlea of the guinea pig using Western blot analysis and immunocytochemistry. By Western blotting, PLCβ1 and δ1 were expressed in the cochlear sensory epithelia (CSE) and PLCβ1, γ1 and δ1 were expressed in the cochlear lateral wall. By immunocytochemistry of the CSE, PLCβ1-like immunoreactivity was mainly expressed in the outer hair cells (OHCs), but not in the inner hair cells (IHCs). PLCγ1 and δ1 were expressed neither in the OHCs nor in the IHCs. In the cochlear lateral wall, PLCβ1, δ1 and γ1 were expressed in the stria vascularis and the spiral ligament. In addition, PLCβ1, δ1 and γ1 were also present in type I spiral ganglion cells. Based on these results, we discussed the function of these PLC isoforms in the cochlea.