Spatial expression patterns of epidermal growth factor receptor gene transcripts in the postnatal mammalian cochlea

• Published in: Hearing research Vol. 141; no. 1; pp. 19 - 27
• Main Authors: Zine, A, Nyffeler, M, de Ribaupierre, F
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2000; Elsevier
• Subjects: Animals; Animals, Newborn; Base Sequence; Biological and medical sciences; Cochlea - growth & development; Cochlea - injuries; Cochlea - metabolism; DNA Primers - genetics; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Epidermal growth factor receptor; Epithelium - metabolism; ErbB Receptors - genetics; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental; In Situ Hybridization; Organ of Corti; Organ of Corti - growth & development; Organ of Corti - injuries; Organ of Corti - metabolism; Rat; Rats; Rats, Sprague-Dawley; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - genetics; RNA, Messenger - metabolism; Vertebrates: nervous system and sense organs; Reverse transcriptase-polymerase chain reaction; Organ of Corti; Rat; In situ hybridization; Epidermal growth factor receptor; Spiral ganglion; Supporting cell; Rodentia; Ciliated cell; Gene expression; Postnatal development; Inner ear; Organ of hearing; Vertebrata; Mammalia; Epidermal growth factor; Cochlea; Peptidergic receptor; Stria vascularis; Differentiation
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(99)00203-8

Recent in vitro studies demonstrated that members of the epidermal growth factor (EGF) family are involved in hair cell replacement in the postnatal mammalian organ of Corti (OC) after ototoxic damage. This suggests a role for the EGF receptor (EGFR) in this process. We examined the expression of EGFR mRNA within the normal postnatal day 3 (P3) and adult rat cochlear epithelium by RT-PCR and examined its cellular localization with non-radioactive in situ hybridization in P3 and adult cochleae. RT-PCR demonstrated that EGFR mRNA is expressed in P3 and adult cochlear epithelium. In situ hybridization localized high levels of EGFR transcripts in the OC, spiral ganglion, Kölliker’s organ and detectable levels in the supporting cells and the stria vascularis of P3 cochlea. In the adult cochlea, EGFR transcripts were detected only in the spiral ganglion. Our results support that the EGFR is implicated in the differentiation of several cochlear cell types and in the response of OC to ototoxic damage of the P3 rat. In the adult, it may participate in the maintenance of the mature neurons and its absence in the OC may contribute to the lack of regenerative responses in the adult cochlea.