Anton F, Herdegen T, Peppel P, Leah J D
Institut für Physiologie und Biokybernetik, Erlangen, F.R.G.
Neuroscience. 1991;41(2-3):629-41. doi: 10.1016/0306-4522(91)90355-r.
It has previously been shown that noxious and non-noxious peripheral stimuli induce c-fos expression in spinal dorsal horn neurons. In the present study we have examined the expression of c-fos in brainstem neurons following noxious chemical stimulation of the respiratory region of the nasal mucosa. In urethane-anaesthetized rats we injected mustard oil or applied CO2 pulses to the right nasal cavity. In control animals we applied paraffin oil or a continuous flow of air. A further group of control animals was anaesthetized and not subjected to any experimental treatment. Two hours after the first stimulus the rats were perfused with 4% phosphate-buffered paraformaldehyde. Brainstem sections were incubated with primary antiserum against the FOS protein and processed according to the ABC method. Only the mustard oil-treated rats had obvious signs of rhinitis and displayed FOS-positive cells in laminae I and II of the subnucleus caudalis and in the subnucleus interpolaris of the trigeminal brainstem nuclear complex as well as in the medullary lateral reticular nucleus. These areas are known to be involved in the processing of nociceptive information. Although CO2 pulses applied to the nasal mucosa are known to evoke pain sensations in man we did not observe any FOS-positive neurons in trigeminal and reticular brainstem areas of CO2-treated rats. This lack of c-fos expression probably results from the fact that unlike mustard oil, CO2 did not induce any apparent inflammatory reactions. In all animals c-fos expression was found in the nucleus of the solitary tract and in the area postrema. Staining in these areas might partly result from factors related to anaesthesia, changed respiration parameters and stress. Since the mustard oil-treated rats displayed the highest levels of immunoreactivity in the nucleus of the solitary tract and in the area postrema, additional effects specifically related to nociceptive input are very likely.
先前的研究表明，有害和无害的外周刺激均可诱导脊髓背角神经元中c-fos的表达。在本研究中，我们检测了对鼻黏膜呼吸区域进行有害化学刺激后脑干神经元中c-fos的表达情况。在氨基甲酸乙酯麻醉的大鼠中，我们向右侧鼻腔注射芥子油或施加二氧化碳脉冲。在对照动物中，我们施加石蜡油或持续的气流。另一组对照动物进行麻醉但不接受任何实验处理。在首次刺激后两小时，用4%的磷酸盐缓冲多聚甲醛灌注大鼠。将脑干切片与抗FOS蛋白的一抗孵育，并按照ABC法进行处理。只有经芥子油处理的大鼠有明显的鼻炎迹象，并且在三叉神经脑干核复合体尾侧亚核的I层和II层、极间亚核以及延髓外侧网状核中显示出FOS阳性细胞。已知这些区域参与伤害性信息的处理。尽管已知向鼻黏膜施加二氧化碳脉冲会在人类中引起疼痛感，但我们在经二氧化碳处理的大鼠的三叉神经和网状脑干区域未观察到任何FOS阳性神经元。c-fos表达的缺乏可能是由于与芥子油不同，二氧化碳未诱导任何明显的炎症反应。在所有动物中，在孤束核和最后区均发现了c-fos表达。这些区域的染色可能部分是由与麻醉、呼吸参数改变和应激相关的因素导致的。由于经芥子油处理的大鼠在孤束核和最后区显示出最高水平的免疫反应性，很可能存在与伤害性输入特别相关的额外效应。
