Age-related changes in two-pore domain acid-sensitive K+ channel expression in rat dorsal root ganglion neurons

• Published in: Clinical and experimental pharmacology & physiology 2012-01, Vol.39 (1), p.43-48
• Main Authors: Kim, Gyu-Tae, Cho, Young-Woo, Tak, Hyun-Min, Lee, Jeong-Soon, Kim, Eun-Jin, Han, Jaehee, Kang, Dawon
• Format: Article
• Language: English
• Subjects: Age; ageing; Aging - metabolism; Animals; Animals, Newborn; Brain; Cells, Cultured; Cercopithecus aethiops; COS Cells; Development; Dorsal root ganglia; Ganglia, Spinal - cytology; Ganglia, Spinal - growth & development; Ganglia, Spinal - metabolism; Gene expression; Gene Expression Regulation, Developmental; Membrane potential; Membrane Potentials; mRNA; Neonates; Nerve Tissue Proteins - genetics; Nerve Tissue Proteins - metabolism; Neurogenesis; Neurons; Neurons - cytology; Neurons - metabolism; Patch-Clamp Techniques; Polymerase chain reaction; Potassium; potassium channel; Potassium channels; Potassium Channels, Tandem Pore Domain - genetics; Potassium Channels, Tandem Pore Domain - metabolism; Protein Isoforms - genetics; Protein Isoforms - metabolism; Rats; Rats, Sprague-Dawley; Recombinant Proteins - metabolism; RNA, Messenger - metabolism; Specific Pathogen-Free Organisms; two-pore domain acid-sensitive K+ (TASK) protein; Western blotting
• ISSN: 0305-1870; 1440-1681
• DOI: 10.1111/j.1440-1681.2011.05634.x

Summary 1. Two‐pore domain K+ (K2P) channel expression influences brain development. The K2P 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 K2P 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.