Talman W T, Granata A R, Reis D J
Fed Proc. 1984 Jan;43(1):39-44.
The nucleus tractus solitarius (NTS), the site of termination of visceral afferents of the ninth and tenth cranial nerves, mediates and integrates the reflex cardiovascular and noncardiovascular responses to stimulation of cardiopulmonary and other visceral afferents. On injection into the NTS, the amino acid L-glutamate (L-Glu) and its excitatory analogs produce dose-dependent hypotension and bradycardia, a baroreceptor reflex-like response. The L-Glu antagonist glutamate diethyl ester blocks the response both to L-Glu and to baroreceptor reflex activation. Electrical stimulation of vagal c-fibers selectively releases 3H into a push-pull cannula after preloading of the NTS with L-[3H]Glu or D-[3H]aspartate. The NTS contains a high-affinity uptake system for inactivation of L-Glu. Like L-Glu, acetylcholine and serotonin, which are also found in the NTS, both elicit a baroreceptor reflex-like response when microinjected into the NTS. However, cholinergic and serotonergic antagonists do not block the baroreceptor reflex. A glutamatergic neuron (or neurons) projecting into NTS appears to be an integral part of the baroreceptor reflex arc.
孤束核（NTS）是第九和第十对脑神经内脏传入纤维的终止部位，介导并整合对心肺及其他内脏传入纤维刺激的反射性心血管和非心血管反应。向NTS内注射氨基酸L-谷氨酸（L-Glu）及其兴奋性类似物会产生剂量依赖性低血压和心动过缓，这是一种类似压力感受器反射的反应。L-Glu拮抗剂谷氨酸二乙酯可阻断对L-Glu以及压力感受器反射激活的反应。在用L-[3H]Glu或D-[3H]天冬氨酸预加载NTS后，电刺激迷走神经c纤维可将3H选择性释放到推挽式插管中。NTS含有一个用于使L-Glu失活的高亲和力摄取系统。与L-Glu一样，NTS中也存在的乙酰胆碱和5-羟色胺，当微量注射到NTS中时，都会引发类似压力感受器反射的反应。然而，胆碱能和5-羟色胺能拮抗剂不会阻断压力感受器反射。投射到NTS的谷氨酸能神经元似乎是压力感受器反射弧的一个组成部分。
