Dun N J, Dun S L, Chiaia N L
Department of Anatomy, Medical College of Ohio, Toledo 43614.
Brain Res. 1993 Apr 16;608(2):223-32. doi: 10.1016/0006-8993(93)91462-2.
In urethane anesthetized rats one hour after lowering the systolic blood pressure to 70-75 mmHg by withdrawing 3-4 ml of blood, Fos immunoreactivity (Fos-IR), confined to the cell nucleus, was detected bilaterally in numerous cells of the nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM). A few Fos-IR neurons were observed in the lateral reticular nucleus, dorsal medullary reticular nucleus, spinal trigeminal nucleus, medial inferior olive, interfasciculus hypoglossi and paramedian rostral medulla. In sham-operated animals, a much smaller number of Fos-IR neurons were scattered in the NTS, VLM and other nuclei mentioned above. Double labeling with antisera to tyrosine-hydroxylase (TH) and phenylethanolamine-N-methyltransferase (PNMT) showed that 60% of TH-positive neurons in the NTS contained Fos-IR, and 70-80% of TH-positive neurons in the caudal VLM and 50-60% of PMNT-positive neurons in the rostral VLM expressed Fos-IR. Only a few TH- or PNMT-positive neurons in the C2, C3 (paramedian rostral medulla) areas and within the medial longitudinal fasciculus were Fos-IR. About 40% of PNMT/Fos-IR neurons in the rostral VLM contained the retrograde tracer fluorogold, which was injected (< 1 microliter) into the white matter dorsolateral to the intermediolateral cell column of T2-T3 segments 2 to 3 days prior to hemorrhagic experiments. Very few TH-positive neurons in the caudal VLM contained fluorogold. Finally, clusters of Fos-IR neurons, which also labeled with antisera to choline acetyltransferase, were detected in the intermediolateral cell column of the spinal cord. The results indicate that during hemorrhage aminergic neurons in the caudal and rostral VLM and in the NTS are activated insofar as c-fos expression is concerned. As a corollary, the monoaminergic neurons in the medulla constitute an essential component in the ascending as well as descending reflex pathway involved in the adjustment of cardiovascular dynamics during hemorrhage.
在氨基甲酸乙酯麻醉的大鼠中，通过抽取3 - 4毫升血液使收缩压降至70 - 75 mmHg 1小时后，在孤束核（NTS）和延髓腹外侧区（VLM）的众多细胞中双侧检测到局限于细胞核的Fos免疫反应性（Fos-IR）。在外侧网状核、延髓背侧网状核、三叉神经脊束核、内侧下橄榄核、舌下神经束间核和延髓嘴侧旁正中核中观察到少量Fos-IR神经元。在假手术动物中，数量少得多的Fos-IR神经元散在于上述NTS、VLM和其他核中。用酪氨酸羟化酶（TH）和苯乙醇胺 - N - 甲基转移酶（PNMT）抗血清进行双重标记显示，NTS中60%的TH阳性神经元含有Fos-IR，尾侧VLM中70 - 80%的TH阳性神经元以及嘴侧VLM中50 - 60%的PNMT阳性神经元表达Fos-IR。在C2、C3（延髓嘴侧旁正中核）区域以及内侧纵束内只有少数TH或PNMT阳性神经元是Fos-IR。嘴侧VLM中约40%的PNMT/Fos-IR神经元含有逆行示踪剂荧光金，该示踪剂在出血实验前2至3天注入（<1微升）到T2 - T3节段中间外侧细胞柱背外侧的白质中。尾侧VLM中极少有TH阳性神经元含有荧光金。最后，在脊髓中间外侧细胞柱中检测到Fos-IR神经元簇，这些神经元也用胆碱乙酰转移酶抗血清标记。结果表明，就c-fos表达而言，在出血期间尾侧和嘴侧VLM以及NTS中的胺能神经元被激活。作为一个推论，延髓中的单胺能神经元构成了在出血期间参与心血管动力学调节的升、降反射通路的重要组成部分。
