Age-related changes in two-pore domain acid-sensitive K⁺ channel expression in rat dorsal root ganglion neurons.
1. Two-pore domain K⁺ (K(2P) ) channel expression influences brain development. The K(2P) channels, including two-pore domain acid-sensitive K⁺ (TASK) channels, contribute to the setting of the resting membrane potential of neurons. In addition to neurons in the brain, dorsal root ganglion (DRG) neurons also express K(2P) channels. The aim of the present study was to identify postnatal changes in the expression of TASK channels in DRG neurons. 2. Expression of TASK channels (TASK-1, TASK-2 and TASK-3) was compared between neonatal (postnatal Day (P) 1 or P2) and adult (P120) rat DRG using semiquantitative polymerase chain reaction, western blot analysis, immunostaining and the patch-clamp technique. 3. In adult (P120) rat DRG, expression of TASK-2 mRNA and protein was downregulated, whereas TASK-3 mRNA and protein expression was upregulated. There were no consistent changes in TASK-1 mRNA and protein expression. Single-channel recordings showed very low TASK-2- and TASK-3-like channel expression in P1-P2 DRG neurons (∼10% in TASK-2 and ∼3% in TASK-3). In P120 DRG, there was a reduction in the detection of TASK-2-like channels, whereas the detection of TASK-3-like channels increased. 4. These results show that TASK-2 and TASK-3 mRNA and protein expression undergoes age-related changes in DRG neurons, indicating that TASK-2 and TASK-3 channels are likely to contribute to the setting of the resting membrane potential of DRG neurons in neonates and adults, separately or together, during DRG development.
Medical Research Centre for Neural Dysfunction, Department of Physiology and Institute of Health Sciences, Gyeongsang National University School of Medicine, Jinju, Korea.
Gyu-Tae
GT
Kim
Young-Woo
YW
Cho
Hyun-Min
HM
Tak
Jeong-Soon
JS
Lee
Eun-Jin
EJ
Kim
Jaehee
J
Han
Dawon
D
Kang
D000375:Aging / Q000378:metabolism*; D000818:Animals; D000831:Animals, Newborn; D019556:COS Cells; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D005727:Ganglia, Spinal / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008564:Membrane Potentials; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D024683:Potassium Channels, Tandem Pore Domain / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000378:metabolism; D013047:Specific Pathogen-Free Organisms
C498740:Kcnk5 protein, rat; C407082:Kcnk9 protein, rat; D009419:Nerve Tissue Proteins; D024683:Potassium Channels, Tandem Pore Domain; D020033:Protein Isoforms; D012333:RNA, Messenger; D011994:Recombinant Proteins; C420132:potassium channel subfamily K member 3