Immunolocalization of peptide 19 and other calcium-binding proteins in the guinea pig cochlea

Abstract

Calcium ions are known to play critical roles in a variety of cochlear functions. The distributions of a number of calcium binding proteins that regulate calcium ion levels within the cochlea have previously been described. In this report we extend and refine previous reports of the distribution of immunostaining for calmodulin, calbindin, and calretinin and show for the first time the distribution for peptide 19. There were longitudinal and radial gradients of immunostaining for peptide 19 within outer hair cells that appeared to match previously described gradients of efferent innervation of these cells. Gradients of immunostaining for calbindin within outer hair cells were in the opposite directions, which suggests that levels of this protein are correlated with afferent innervation density and perhaps the abundance of subsurface cisternae. No gradients were seen in the distributions of cells stained for calmodulin and calretinin, which included sensory cells and supporting cells respectively. All ganglion cells were stained for calmodulin but the other proteins appeared to be present in limited ganglion cell subpopulations. In addition to staining of sensorineural elements, antisera to all compounds but peptide 19 showed immunostaining of cells within the lateral wall and the spiral limbus. The results suggest that the proteins under study are involved in a wide variety of calcium-regulated functions within the cochlea. Knowledge of the unique distribution of each of the compounds should facilitate further studies of their roles in cochlear function.

Immunohistochemical Localization of Ca2+/Calmodulin-dependent Protein Kinase IV in Outer Hair Cells

“…The question arises then concerning the presence and possible role of CaM kinases in regulating OHC activity. The presence of calmodulin in OHCs (Slepecky and Ulfendahl 1993;Pack and Slepecky 1995;Imamura and Adams 1996) and a recent study documenting the inhibition of Ca 2 ϩ -induced slow motility by CaM kinase inhibitors support the enzymes' activity in OHCs (Puschner and Schacht 1997). This study sought further evidence for this by undertaking to localize CaM kinases in the inner ear immunohistochemically.…”

Distribution of Gentamicin in the Guinea Pig Inner Ear after Local or Systemic Application

“…Deparaffinized sections were immunostained with the biotin-amplified ABC method (Adams 1992;Imamura and Adams 1996). A monoclonal antibody against gentamicin (Fitzgerald Industries International Inc., Chelmsford, MA) was used.…”

Changes in Cytochemistry of Sensory and Nonsensory Cells in Gentamicin-Treated Cochleas

“…The large number of calcium-binding proteins in the present study was included because their individual characteristic distributions suggest that they serve different functions within the cochlea (e.g., Pack and Slepecky 1995;Imamura and Adams 1996). Changes in these proteins and the calcium pumps were among the most sensitive indicators that gentamicin administration had affected individual cells.…”