Pain Research Center, Department of Anesthesiology, The University of Cincinnati College of Medicine, PO Box 670531, 231 Albert Sabin Way, Cincinnati, OH 45267, USA.
Mol Brain. 2013 Dec 17;6:57. doi: 10.1186/1756-6606-6-57.
Rapidly adapting mechanically activated channels (RA) are expressed in primary afferent neurons and identified as Piezo2 ion channels. We made whole-cell voltage-clamp recordings from cultured dorsal root ganglion (DRG) neurons to study RA channel regulation. RA currents showed gradual increases in current amplitude (current "run-up") after establishing whole-cell mode when 0.33 mM GTP or 0.33 mM GTPγS was included in the patch pipette internal solution. RA current run-up was also observed in HEK293 cells that heterologously expressed Piezo2 ion channels. No significant RA current run-up was observed in DRG neurons when GTP was omitted from the patch pipette internal solution, when GTP was replaced with 0.33 mM GDP, or when recordings were made under the perforated patch-clamp recording configuration. Our findings revealed a GTP-dependent up-regulation of the function of piezo2 ion channels in DRG neurons.
快速适应机械激活通道（RA）表达在初级传入神经元中，并被鉴定为 Piezo2 离子通道。我们从培养的背根神经节（DRG）神经元中进行全细胞膜片钳记录，以研究 RA 通道调节。当在膜片钳内液中包含 0.33 mM GTP 或 0.33 mM GTPγS 时，在建立全细胞膜片钳模式后，RA 电流的电流幅度（电流“上升”）逐渐增加。在异源表达 Piezo2 离子通道的 HEK293 细胞中也观察到 RA 电流上升。当膜片钳内液中不包含 GTP 时，当 GTP 被 0.33 mM GDP 取代时，或当在穿孔膜片钳记录构型下进行记录时，在 DRG 神经元中未观察到明显的 RA 电流上升。我们的发现揭示了 GTP 依赖性的 DRG 神经元中 piezo2 离子通道功能的上调。
