Cunningham J T, Wachtel R E, Abboud F M
Department of Physiology, Dalton Cardiovascular Research Center, University of Missouri, Columbia, USA.
Brain Res. 1997 May 16;757(1):149-54. doi: 10.1016/s0006-8993(97)00153-4.
We investigated the responses of putative aortic baroreceptor neurons to mechanical stimulation of their processes. Putative aortic baroreceptor neurons were identified by applying the carbocyanine dye DiI to the adventitia of the aortic arch of anesthetized rats. After at least 1 week, the nodose ganglia were removed and the neurons were cultured. Within 2-3 days, neurite outgrowth was evident on many neurons. The soma was voltage-clamped using whole cell patch clamp techniques while the neurites were deformed with pneumatic ejection of bath solution at 5-15 psi using a glass pipette (7-15 microm) positioned at least 50 microm from the neurite. Mechanical stimulation induced an inward current in 15 out of 17 putative aortic baroreceptor neurons. The magnitude of the current was related to the intensity of stimulation. The current was blocked by 20 microM gadolinium (n = 11), a reported blocker of mechanically sensitive ion channels, or by incubating the cells overnight in 10 microM phalloidin, which binds to actin filaments (n = 5). We conclude that mechanical deformation of neurites of putative baroreceptor neurons activates a mechanosensitive inward current in the soma and that the cytoskeletal actin filaments are involved in the generation of this current.
我们研究了假定的主动脉压力感受器神经元对其突起机械刺激的反应。通过将羰花青染料DiI应用于麻醉大鼠主动脉弓外膜来识别假定的主动脉压力感受器神经元。至少1周后，取出结状神经节并培养神经元。在2 - 3天内，许多神经元上明显有神经突生长。使用全细胞膜片钳技术对胞体进行电压钳制，同时使用一个距离神经突至少50微米的玻璃微管（7 - 15微米）以5 - 15磅力/平方英寸的气压喷射浴液使神经突变形。机械刺激在17个假定的主动脉压力感受器神经元中的15个中诱导出内向电流。电流大小与刺激强度相关。该电流被20微摩尔钆（n = 11）阻断，钆是一种已报道的机械敏感离子通道阻断剂，或者通过将细胞在10微摩尔鬼笔环肽中孵育过夜阻断，鬼笔环肽可与肌动蛋白丝结合（n = 5）。我们得出结论，假定压力感受器神经元神经突的机械变形在胞体中激活了机械敏感内向电流，并且细胞骨架肌动蛋白丝参与了该电流的产生。
