大鼠“延髓内脏带”向杏仁核投射的儿茶酚胺神经元对内脏伤害性刺激的FOS表达

VISCERAL NOXIOUS STIMULATION INDUCED FOS EXPRESSION OF CATECHOLAMINERGIC NEURONS IN THE "MEDULLARY VISCERAL ZONE" PROJECTING TO THE CENTRAL AMYGDALOID NUCLEUS

本文通过建立ＨＲＰ逆行追踪结合抗ＦＯＳ和抗酪氢酸羟化酶（ＴＨ）的免疫组织化学三重标记技术，在延髓见到以下七种标记细胞：ＦＯＳ，ＨＲＰ，ＴＨ单标细胞，ＦＯＳ／ＨＲＰ，ＦＯＳ／ＴＨ，ＨＲＰ／ＴＨ双标细胞，ＦＯＳ／ＨＲＰ／ＴＨ三标细胞。这些细胞主要分布于延髓中、尾段由孤束核、腹外侧区以及在两者之间的网状结构共同组成的弧形带状区──“延髓内脏带”。本文结果表明大鼠“延髓内脏带”向杏仁核直接投射的儿茶酚胺能神经元中约有４８％对内脏伤害性刺激起反应，提示“延髓内脏带”及其向杏仁核的儿茶酚胺能投射通路参与机体应激反应的调控过程。

In the present study a triple labeling method, in which horseradish peroxidase (HRP) retrograde tracing was combined with FOS and tyrosine hydroxylase (TH) immunohistochemistry,was developed, i. e. HRP was stereotaxically injected into central amygdaloid nucleus (Ce) unilaterally, after 48h survival, formalin was introduced into the stomach as visceral noxious stimulus,then the animals were allowed to survive 2h and sacrificed, and the histochemical demonstration of HRP and immunohistochemistry for FOS and TH were carried out. Under light microscope seven kinds of labeled neurons were found in the sections of medulla:FOS-like immunoreactive (FOS-LI) neurons, HRP retrograde labeled neurons, TH-like immunoreactive (TH-LI) neurons, FOS/HRP-, FOS/TH-, HRP/TH- double labeled neurons and FOS/HRP/TH-triple labeled neurons. These different labeled neurons were mainly distributed within an arc zone which was consisted of nucleus tractus solitarii (NTS), ventrolateral medulla (VLM)and the reticular formation (RF) between NTS and VLM (we named the arc zone as medulllary visceral zone, MVZ). The result indicated that some catecholaminergic neurons projecting to the Ce in the MVZ reacted to the visceral noxious stimulation (FOS expression). It is suggested that the projection pathways from the MVZ to the Ce are involved in the control process of stress responses to the noxious stimulation.