Premium
Immunohistochemical localization of adrenergic receptors in the rat organ of corti and spiral ganglion
Author(s) -
Khan Khalid M.,
Drescher Marian J.,
Hatfield James S.,
Ramakrishnan Neeliyath A.,
Drescher Dennis G.
Publication year - 2007
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21404
Subject(s) - spiral ganglion , organ of corti , hair cell , ganglion , cochlea , biology , inner ear , anatomy , receptor , microbiology and biotechnology , neuroscience , biochemistry
α 1 ‐, β 1 ‐, and β 2 ‐adrenergic receptors (ARs), which mediate responses to adrenergic input, have been immunohistochemically identified within the organ of Corti and spiral ganglion with polyclonal antibodies of established specificity. α 1 ‐AR was immunolocalized to sites overlapping supranuclear regions of inner hair cells as well as to nerve fibers approaching the base of inner hair cells, most evident in the basal cochlear turn. A similar preponderance across cochlear turns for α 1 ‐AR in afferent cell bodies in the spiral ganglion pointed to type I afferent dendrites as a possible neural source of α 1 ‐AR beneath the inner hair cell. Foci of immunoreactivity for α 1 ‐AR, putatively neural, were found overlapping supranuclear and basal sites of outer hair cells for all turns. β 1 ‐ and β 2 ‐ARs were immunolocalized to sites overlapping apical and basal poles of the inner and outer hair cells, putatively neural in part, with immunoreactive nerve fibers observed passing through the habenula perforata. β 1 ‐ and β 2 ‐ARs were also detected in the cell bodies of Deiters' and Hensen's cells. Within the spiral ganglion, β 1 ‐ and β 2 ‐ARs were immunolocalized to afferent cell bodies, with highest expression in the basal cochlear turn, constituting one possible neural source of receptors within the organ of Corti, specifically on type I afferent dendrites. β 1 ‐ and β 2 ‐ARs in Hensen's and Deiters' cells would couple to Gαs, known to be present specifically in the supporting cells. Overall, adrenergic modulation of neural/supporting cell function within the organ of Corti represents a newly considered mechanism for modifying afferent signaling. © 2007 Wiley‐Liss, Inc.