title: Developmental expression of two-pore domain K+ channels, TASK-1 and TREK-1, in the rat cochlea.
abstract: Developmental expression of two-pore domain potassium (2P K) channels, TASK-1 and TREK-1, was investigated in the rat cochlea at onset of hearing and after maturity using RT-PCR and immunocytochemistry. TASK-1 and TREK-1 mRNAs were detected by RT-PCR at postnatal day (P) 9-12. TASK-1 like immunoreactivity (LIR) in the P13 cochlea was observed in Deiters', pillar, Claudius' and outer sulcus cells, spiral limbus fibrocytes, and neuroglia. At P13, TREK-1-LIR was more wide-spread, and included sensory and supporting cells of the organ of Corti, spiral ganglion, stria vascularis, Reissner's membrane, inner and outer sulcus cells, connective and support tissues surrounding modiolus. By P105 the pattern of TASK-1- and TREK-1-LIR became limited to a subset of the above structures, suggesting developmental regulation. During postnatal development, TASK-1 may be important in the onset (around P11) and maturation (by P22) of endocochlear potential and hearing. The distribution of TASK-1 and TREK-1 suggest a role in K cycling and homeostasis. As TASK-1 and TREK-1 are inhibited by local anesthetics at doses used to treat tinnitus, 2P K channels may also be important in cochlear dysfunction.
authors.affiliation: School of Biomedical Sciences, University of Queensland, St Lucia 4072 QLD, Australia. r.kanjhan@uq.edu.au
authors.forename: Refik
authors.initials: R
authors.lastname: Kanjhan
authors.forename: Caroline L
authors.initials: CL
authors.lastname: Balke
authors.forename: Gary D
authors.initials: GD
authors.lastname: Housley
authors.forename: Mark C
authors.initials: MC
authors.lastname: Bellingham
authors.forename: Peter G
authors.initials: PG
authors.lastname: Noakes
mesh_terms: D000818:Animals; D003051:Cochlea / Q000254:growth & development* / Q000378:metabolism; D005072:Evoked Potentials, Auditory / Q000502:physiology; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D006309:Hearing / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D007150:Immunohistochemistry; D008856:Microscopy, Fluorescence; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009925:Organ of Corti / Q000254:growth & development / Q000378:metabolism; D015221:Potassium Channels / Q000096:biosynthesis* / Q000235:genetics; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology; D013136:Spiral Ganglion / Q000254:growth & development / Q000378:metabolism
chemical_list: D009419:Nerve Tissue Proteins; D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger; C103742:potassium channel protein TREK-1; C420132:potassium channel subfamily K member 3