title: Deafness associated changes in expression of two-pore domain potassium channels in the rat cochlear nucleus.
abstract: Two-pore domain potassium channels (K(2PD)+) play an important role in setting resting membrane potential by regulating background leakage of potassium ions, which in turn controls neuronal excitability. To determine whether these channels contribute to activity-dependent plasticity following deafness, we used quantitative real-time PCR to examine the expression of 10 K(2PD)+ subunits in the rat cochlear nucleus at 3 days, 3 weeks and 3 months after bilateral cochlear ablation. There was a large sustained decrease in the expression of TASK-5, a subunit that is predominantly expressed in auditory brain stem neurons, and in the TASK-1 subunit which is highly expressed in several types of cochlear nucleus neurons. TWIK-1 and THIK-2 also showed significant decreases in expression that were maintained across all time points. TWIK-2, TREK-1 and TREK-2 showed no significant change in expression at 3 days but showed large decreases at 3 weeks and 3 months following deafness. TRAAK and TASK-3 subunits showed significant decreases at 3 days and 3 weeks following deafness, but these differences were no longer significant at 3 months. Dramatic changes in expression of K(2PD)+ subunits suggest these channels may play a role in deafness-associated changes in the excitability of cochlear nucleus neurons.
authors.affiliation: Kresge Hearing Research Institute, Department of Otolaryngology, Head and Neck Surgery, University of Michigan, 1301 East Ann Street, Ann Arbor, MI 48109-0506, USA. avrilhol@umich.edu
authors.forename: Avril Genene
authors.initials: AG
authors.lastname: Holt
authors.forename: Mikiya
authors.initials: M
authors.lastname: Asako
authors.forename: R Keith
authors.initials: RK
authors.lastname: Duncan
authors.forename: Catherine A
authors.initials: CA
authors.lastname: Lomax
authors.forename: Jose M
authors.initials: JM
authors.lastname: Juiz
authors.forename: Richard A
authors.initials: RA
authors.lastname: Altschuler
mesh_terms: D000818:Animals; D017626:Cochlear Nucleus / Q000166:cytology / Q000503:physiopathology*; D018076:DNA, Complementary / Q000737:chemistry; D003638:Deafness / Q000473:pathology / Q000503:physiopathology*; D016057:Evoked Potentials, Auditory, Brain Stem; D008297:Male; D009473:Neuronal Plasticity / Q000502:physiology*; D024683:Potassium Channels, Tandem Pore Domain / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000302:isolation & purification; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018076:DNA, Complementary; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger