Expression of plasma membrane Ca-ATPase in the adult and developing gerbil cochlea

• Published in: Hearing research Vol. 92; no. 1; pp. 112 - 119
• Main Authors: Crouch, James J., Schulte, Bradley A.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.12.1995; Elsevier
• Subjects: Aging - metabolism; Animals; Antibodies, Monoclonal; Biological and medical sciences; Calcium; Calcium-Transporting ATPases - metabolism; Cell Membrane - enzymology; Cochlea - cytology; Cochlea - enzymology; Cochlea - ultrastructure; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Endolymph; Epithelium - enzymology; Erythrocytes - enzymology; Female; Fundamental and applied biological sciences. Psychology; Gerbillinae; Hair cell; Hair Cells, Auditory, Inner - cytology; Hair Cells, Auditory, Inner - enzymology; Hair Cells, Auditory, Outer - cytology; Hair Cells, Auditory, Outer - enzymology; Homeostasis; Humans; Immunoenzyme Techniques; Immunohistochemistry; Ion transport; Male; Signal Transduction - physiology; Spiral Ganglion - cytology; Spiral Ganglion - enzymology; Vertebrates: nervous system and sense organs; Immunohistochemistry; Ion transport; Homeostasis; Hair cell; Endolymph; Calcium; Enzyme; Rodentia; Adenosinetriphosphatase; Inner ear; Organ of hearing; Vertebrata; Mammalia; Plasma membrane; Cochlea; Development; Hydrolases; Gerbil
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/0378-5955(95)00201-4

The distribution of the plasma membrane Ca-ATPase (PMCA) was mapped in the adult and developing gerbil cochlea by immunostaining with a monoclonal antibody against the human erythrocyte PMCA. In the mature cochlea, intense immunoreactivity was present at the surface of stereocilia of both inner (IHC) and outer (OHC) hair cells. The basolateral plasma membrane of IHCs but not OHCs stained strongly whereas that of strial marginal cells and the epithelial cell layer of Reissner's membrane showed only weak reactivity. Nerve terminals underlying IHCs were also selectively stained. At birth, strong to moderate reactivity for PMCA was present in the basolateral plasma membrane of IHCs and OHCs, strial marginal cells, and epithelial cells lining the scala media surface of Reissner's membrane and in the neurolemma of spiral ganglion cells. Immunostaining in the basolateral plasmalemma of OHCs, strial marginal cells, and epithelial cells lining Reissner's membrane remained strong to moderate up to 14 days after birth when it diminished or disappeared entirely, suggesting a developmental role for PMCA activity in these sites. Expression of PMCA at the surface of IHC and OHC stereocilia was first observed at 10 days after birth and staining reached adult levels by 14 days after birth. The abundance of PMCA in the stereociliary plasma membrane of mature hair cells supports the suggested involvement of Ca 2+ in regulating transduction and adaptation mechanisms.