Tsukahara R, Mano T
Institute for Developmental Research, Aichi Human Service Center, Japan.
J Auton Nerv Syst. 1997 Sep 10;66(1-2):26-34. doi: 10.1016/s0165-1838(97)00041-6.
The aim of this study is to determine the recruitment pattern among individual vasoconstrictor neurons under the baroreceptor-mediated influence in man. Spikes of single vasoconstrictor units were detected from microneurograms with a template-matching method. A total of 39 single vasoconstrictor units were detected. Single vasoconstrictor units were different from each other in their susceptibility to be activated in response to changes in the R-R interval or blood pressure. The units with higher firing probability had a shorter threshold R-R interval and a higher threshold diastolic blood pressure than units with lower firing probability. In sympathetic responses consisting of only one spike (single-spike responses), units with a lower threshold frequently appeared and units with a higher threshold joined mull-spike responses. The units with a short threshold R-R interval tended to have a long inhibitory latency from R wave, suggesting low conduction velocity. The correlation between firing probability and firing threshold and that between appearance in single-spike response and multi-spike response suggest a hierarchical manner of recruitment of vasoconstrictor units. For beat-to-beat responses, however, some deviation from the hierarchical recruitment was also observed.
本研究旨在确定在压力感受器介导的影响下，人体单个血管收缩神经元的募集模式。采用模板匹配法从微神经图中检测单个血管收缩单位的放电。共检测到39个单个血管收缩单位。单个血管收缩单位对R-R间期或血压变化的激活敏感性各不相同。放电概率较高的单位比放电概率较低的单位具有更短的阈值R-R间期和更高的阈值舒张压。在仅由一个峰电位组成的交感反应（单峰反应）中，阈值较低的单位频繁出现，而阈值较高的单位则参与多峰反应。阈值R-R间期较短的单位往往从R波开始具有较长的抑制潜伏期，提示传导速度较慢。放电概率与放电阈值之间的相关性以及单峰反应和多峰反应中出现情况之间的相关性表明血管收缩单位的募集存在分层方式。然而，对于逐搏反应，也观察到了一些与分层募集的偏差。
