Tkacs N C, Li J, Strack A M
Department of Psychiatry, UMDNJ-New Jersey Medical School, Newark 07103, USA.
J Comp Neurol. 1997 Mar 24;379(4):592-602. doi: 10.1002/(sici)1096-9861(19970324)379:4<592::aid-cne9>3.0.co;2-y.
The distribution and time course of Fos expression in neurons in the central nucleus of the amygdala (CeA) were studied in endotoxemic rats in two separate experiments. In each case, the severity of the endotoxin (lipopolysaccharide; LPS) challenge was characterized by using physiological outcome variables, including blood pressure and heart rate. Throughout the rostrocaudal extent of the CeA, extensive Fos staining was found 3 hours after injection with a hypotensive dose of Salmonella enteritidis LPS. Hypotension alone has been reported to induce Fos in the CeA; therefore, the remaining experiments were performed by using a lower dose of Escherichia coli LPS that did not cause hypotension. The nonhypotensive dose of E. coli LPS also induced Fos in large numbers of neurons of the CeA, with peak staining at 2 hours and Fos staining persisting for 6 hours after LPS injection. Tachycardia and fever after LPS also persisted for at least 6 hours. CeA Fos staining during nonhypotensive endotoxemia was predominantly located in the lateral subnucleus, although Fos-stained medial sub-nucleus neurons were also present. Additional forebrain regions that showed persistent Fos staining 6 hours after LPS included the parvocellular paraventricular nucleus of the hypothalamus, the bed nucleus of the stria terminalis, and the medial preoptic area. Forebrain regions that contained Fos-stained nuclei at earlier time points, but not at 6 hours, included the supraoptic nucleus, magnocellular regions of the paraventricular nucleus of the hypothalamus, the subfornical organ, and the organum vasculosum of the lamina terminalis. Few CeA neurons showed Fos staining in rats that were restrained in a ventilated plastic tube. Neurons in the lateral septal nucleus and the medial amygdaloid nucleus, which have numerous Fos-stained nuclei after stressors such as footshock or restraint, did not show Fos staining above control levels after LPS administration. Activation of CeA neurons after intravenous LPS may indicate persistent drive from vagal afferents and may implicate the CeA in the autonomic, neuroendocrine, and/or behavioral responses to this treatment.
在两个独立实验中，研究了内毒素血症大鼠杏仁核中央核（CeA）神经元中Fos表达的分布和时间进程。在每种情况下，通过使用包括血压和心率在内的生理结果变量来表征内毒素（脂多糖；LPS）攻击的严重程度。在向尾侧延伸的整个CeA范围内，注射低血压剂量的肠炎沙门氏菌LPS 3小时后发现广泛的Fos染色。据报道，单独的低血压会诱导CeA中的Fos；因此，其余实验使用不会引起低血压的较低剂量大肠杆菌LPS进行。非低血压剂量的大肠杆菌LPS也在CeA的大量神经元中诱导Fos，在注射LPS后2小时达到染色峰值，Fos染色持续6小时。LPS后的心动过速和发热也至少持续6小时。在非低血压性内毒素血症期间，CeA Fos染色主要位于外侧亚核，尽管也存在Fos染色的内侧亚核神经元。LPS 6小时后显示持续Fos染色的其他前脑区域包括下丘脑小细胞室旁核、终纹床核和内侧视前区。在较早时间点含有Fos染色核但在6小时时不含有的前脑区域包括视上核、下丘脑室旁核的大细胞区域、穹窿下器官和终板血管器。在置于通风塑料管中受限的大鼠中，很少有CeA神经元显示Fos染色。外侧隔核和内侧杏仁核中的神经元，在诸如足部电击或受限等应激源后有许多Fos染色核，但在给予LPS后未显示出高于对照水平的Fos染色。静脉注射LPS后CeA神经元的激活可能表明迷走神经传入的持续驱动，并可能使CeA参与对该治疗的自主、神经内分泌和/或行为反应。
