钾离子通道TASK-1 mRNA在大鼠呼吸中枢的分布

The distribation of TASK-1 mRNA in rat respiratory center

目的:TASK-1是一种对生理范围内pH值敏感的二孔漏钾通道。本研究的目的是探讨TASK-1mRNA在脑干呼吸中枢的分布。方法:使用地高辛标记的寡核苷酸探针与脑干冰冻切片进行原位杂交,检测TASK-1mRNA在脑干呼吸相关神经元中的表达。通过免疫荧光组织化学方法来明确表达TASK-1mRNA的神经元类型。结果:TASK-1 mRNA在最主要的上气道运动神经核团-舌下神经核中有强表达。TASK-1 mRNA在延髓腹侧和背侧的中枢化学感受器神经核团上广泛分布且有较强表达,包括孤束核(nucleus tractus solitarius,NTS)、迷走神经背核(dorsal vagus motor nucleus,DMV)、前包氏复合体(pre-Btzinger complex,pre-BtC)、斜方体后核(retrotrapezoid nucleus,RTN)、尾段延髓中缝核团(caudal medullary raphe nuclei)以及蓝斑(the locus coeruleus,LOC)等部位。TASK-1 mRNA在脑桥呼吸组、桥脚被盖神经核(PPN)、三叉神经中间部位(IRT)等则表达较弱。结论:TASK-1 mRNA在脑干呼吸相关神经元上广泛表达,从解剖学分布上提示它可能以某种形式参与中枢的呼吸调控过程。

Objective： TASK-1 is a two-pore domain＇leak＇ potassium channel, which is sensitive to the extracellular pH within physiological range. The research was aimed to explore TASK-1 mRNA distribution in the respiratory center of the brainstem in rats. Methods： Digoxigenin-labeled oligonucleotide probe was used in in situ hybridization with the brainstem frozen slices to systemically examine the expression of TASK-1 mRNA in brainstem breathing-related neurons. hnmunofluorescence was used to identify some specific neurons which expressed TASK-1. Results： TASK-1 mRNAs were widely expressed in the hypoglossal nueleaus （ Hg）, which is the most important upper airway motoneuron. TASK-1 mR- NAs were expressed widely and highly in all central chemoreceptors （ CCRs ） , including the nucleus tractus solitarius （NTS） , dorsal motor nucleus of vagus （DMV） , pre-Btitginger complex, retrotrapezoid （RTN） , caudal medullary raphe nuclei, and the locus eoeruleus （LOC）, etc. TASK-1 mRNAs were expressed weakly in the pontine respiratory group, the pedunculopontine tegmental nucleus （PPN） and the intertrigeminal region （IRT）. Conclusion： The fact that TASK- 1 mRNAs were widely located in the brainstem breathing-related neurons suggested that TASK-1 channel might take part in the central breathing regulation.