Clement M E, McCall R B
Cardiovascular Diseases Research, Upjohn Company, Kalamazoo, MI 49001.
Brain Res. 1992 Jul 31;587(1):115-22. doi: 10.1016/0006-8993(92)91435-h.
We examined the effects of 8-OH-DPAT and 5-HT on three types of sympathetic-related neurons identified in the lateral tegmental field of anesthetized cats using spike-triggered averaging techniques. Based on their response to baroreceptor activation, these neurons could be classified as sympathoexcitatory, sympathoinhibitory, or baroreceptor activation unresponsive. 8-OH-DPAT administered intravenously was found to inhibit sympathoexcitatory neurons with a high degree of correlation to inhibition of sympathetic activity, and to excite sympathoinhibitory neurons in a dose-dependent manner. Iontophoretic application of 8-OH-DPAT and 5-HT to the majority of sympathoexcitatory neurons caused inhibition of spontaneous activity while iontophoretic application of 8-OH-DPAT to sympathoinhibitory neurons had variable effects although 5-HT consistently caused excitation. Baroreceptor unresponsive neurons were insensitive to iontophoretic 8-OH-DPAT and showed only limited response to 5-HT. It is concluded that the lateral tegmental field plays an important role in the sympathoinhibitory action of 8-OH-DPAT.
我们运用触发峰电位平均技术，研究了8-羟基二丙胺（8-OH-DPAT）和5-羟色胺（5-HT）对麻醉猫外侧被盖区三种与交感神经相关的神经元的作用。根据这些神经元对压力感受器激活的反应，可将它们分为交感兴奋型、交感抑制型或对压力感受器激活无反应型。静脉注射8-OH-DPAT被发现可抑制交感兴奋型神经元，且与交感神经活动的抑制高度相关，并以剂量依赖方式兴奋交感抑制型神经元。对大多数交感兴奋型神经元进行离子电泳施加8-OH-DPAT和5-HT会导致自发活动受到抑制，而对交感抑制型神经元进行离子电泳施加8-OH-DPAT则有不同的效果，尽管5-HT始终会引起兴奋。对压力感受器无反应的神经元对离子电泳的8-OH-DPAT不敏感，对5-HT仅表现出有限的反应。得出的结论是，外侧被盖区在8-OH-DPAT的交感抑制作用中起重要作用。
