Herdegen T, Sandkühler J, Gass P, Kiessling M, Bravo R, Zimmermann M
II. Institute of Physiology, University of Heidelberg, Germany.
J Comp Neurol. 1993 Jul 8;333(2):271-88. doi: 10.1002/cne.903330212.
The expression of the nuclear c-JUN, JUN B, JUN D, c-FOS, FOS B, KROX-24, and CREB transcription factors was investigated in the cortex of adult rats by immunocytochemistry. The expression patterns were studied in untreated rats and up to 24 hours following topical application of 1 M KCl to the cortical surface (KCl) or i.v. injection of bicuculline (BIC). Topical KCl induced cortical spreading depression and systemic injection of bicuculline evoked generalized tonic-clonic seizures. In untreated rats, JUN B, c-FOS, and FOS B were expressed in a small number of neurons in the piriform, perirhinal, entorhinal, and insular cortex and in layers II, III, and VI of all neocortical areas. In contrast, c-JUN, JUN D, and KROX-24 were expressed in all cortical layers but with different intensities of immunoreactivity (IR): c-JUN-IR was generally weak and predominantly present in layers II, III, and VI. JUN D-IR was equally strong in all layers. KROX-24 showed a prominent expression in layers II, IV, and VI. The CREB protein exhibited a slight preponderance in layer II and piriform cortex. Following KCl or BIC, a strong induction was seen for c-FOS, JUN B, and KROX-24, whereas c-JUN, JUN D, and FOS B showed only a moderate increase compared to basal levels. Changes of CREB-IR could not be detected. The localization of induced JUN, FOS, and KROX proteins reflected the pattern of labelling in untreated animals but demonstrated a higher intensity of labelling and an increased number of immunoreactive nuclei. The intensity and persistence of IR as well as the number of labelled cells following BIC exceeded those following KCl. Following BIC, increased levels of FOS B and JUN D were still present after 24 hours. Counterstaining with cresyl-violet and GFAP, a marker for astrocytes, revealed that JUN, FOS, and KROX proteins were expressed in neurons but not in glial cell populations. The present data demonstrate that CREB, JUN, FOS, and KROX transcription factors exhibit a layer-specific expression in the cerebral cortex with only slight area-specific differences both in untreated rats and following stimulation with KCl and BIC. The expression of transcription factor proteins indicate complex molecular genetic changes in cortical neurons due to pathophysiological events such as seizure activity and spreading depression.
通过免疫细胞化学方法研究了成年大鼠皮质中核c-JUN、JUN B、JUN D、c-FOS、FOS B、KROX-24和CREB转录因子的表达。在未处理的大鼠以及向皮质表面局部应用1 M KCl（KCl）或静脉注射荷包牡丹碱（BIC）后长达24小时的大鼠中研究了表达模式。局部应用KCl可诱导皮质扩散性抑制，全身注射荷包牡丹碱可诱发全身性强直阵挛性癫痫发作。在未处理的大鼠中，JUN B、c-FOS和FOS B在梨状皮质、嗅周皮质、内嗅皮质和岛叶皮质的少数神经元以及所有新皮质区域的II、III和VI层中表达。相比之下，c-JUN、JUN D和KROX-24在所有皮质层中均有表达，但免疫反应强度（IR）不同：c-JUN-IR通常较弱，主要存在于II、III和VI层。JUN D-IR在所有层中同样强烈。KROX-24在II、IV和VI层中表达突出。CREB蛋白在II层和梨状皮质中略有优势。在KCl或BIC处理后，c-FOS、JUN B和KROX-24出现强烈诱导，而c-JUN、JUN D和FOS B与基础水平相比仅适度增加。未检测到CREB-IR的变化。诱导的JUN、FOS和KROX蛋白的定位反映了未处理动物中的标记模式，但显示出更高的标记强度和更多的免疫反应性细胞核。BIC处理后的IR强度和持续性以及标记细胞数量超过了KCl处理后的情况。在BIC处理后24小时，FOS B和JUN D的水平仍然升高。用甲酚紫和星形胶质细胞标志物GFAP进行复染显示，JUN、FOS和KROX蛋白在神经元中表达，而不在胶质细胞群体中表达。目前的数据表明，CREB、JUN、FOS和KROX转录因子在大脑皮质中呈现层特异性表达，在未处理的大鼠以及用KCl和BIC刺激后仅存在轻微的区域特异性差异。转录因子蛋白的表达表明，由于癫痫活动和扩散性抑制等病理生理事件，皮质神经元发生了复杂的分子遗传变化。
