Localization of TREK-1, a two-pore-domain K+ channel in the peripheral vestibular system of mouse and rat.
The distribution of two-pore-domain (2P-domain) K(+) channels of the TREK subfamily was studied using immunocytochemistry in the peripheral vestibular system of mouse and rat. Using RT-PCR, the mRNA for TREK-1, but not for TREK-2 or TRAAK, were detected in mouse vestibular endorgans and ganglia. The TREK-1 channel protein was immunodetected in both nerve fibers and nerve cell bodies in the vestibular ganglion, both afferent fibers and nerve calyces innervating type I hair cells in the utricle and cristae. The post-synaptic localization in afferent calyces may suggest a neuroprotective role in glutamatergic excitotoxicity during ischemic conditions. In non-neuronal cells, TREK-1 was immunodetected in the apical membrane of dark cells and transitional cells, both of which are involved in endolymph K(+) secretion and recycling. TREK-1 may subserve some neuroprotective function in afferent nerve fibers as well as play a role in endolymph potassium homeostasis.
Nicolas
Marie-Thérèse
MT
Université Montpellier 2, Place Eugène Bataillon, P.O. Box 089, 34095 Montpellier, cedex 05, France. mnicolas@uni-montp2.fr
Lesage
Florian
F
Reyes
Roberto
R
Barhanin
Jacques
J
Demêmes
Danielle
D
D000818:Animals; D000831:Animals, Newborn; D015139:Blotting, Southern / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D051379:Mice; D018613:Microscopy, Confocal / Q000379:methods; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011920:Rats, Inbred WF; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014725:Vestibular Nerve / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*
D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; D012333:RNA, Messenger; C103742:potassium channel protein TREK-1