ABSTRACT

Objectives

This study explored the possible role of orexin one receptors (Orx1R) in the basolateral amygdala (BLA) on the modulation of nitroglycerin (NTG)-induced migraine-like symptoms. In addition, pain-induced subsequent alteration in learning and memory competence was evaluated in the adult male Wistar rats.

Methods

The rats were given NTG (5 mg/kg, i.p.) every two days (for nine-day) to induce a migraine-like state. The migraine animals were treated with intra-BLA infusion of an Orx1R antagonist SB 334,867 (10, 20, and 40 nM/rat) or its vehicle DMSO. The NTG-induced migraine symptoms were recorded for 90 min. Spatial and passive avoidance performances were assessed by Morris water maze (MWM) and shuttle box tasks, respectively.

Results

In comparison with control, NTG produced significant migraine-like symptoms characterized by a decrease in cage climbing and an increase in head-scratching, freezing, and facial grooming behavior. Intra-BLA infusion of SB 334,867 (40 nM/rat) significantly decreased cage climbing and increased facial grooming responses in NTG-treated rats. Moreover, all administrated doses of SB 334,867 increased NTG-evoked head-scratching and freezing behavior. Besides, NTG impaired learning and memory performances in both tests, which were exaggerated by post-injection of SB 334,867 (40 nM/rat).

Conclusions

Overall, the data provided an emerging role for the orexin system within BLA in the modulation of cognitive decline comorbid with migraine in rats.

中文翻译：

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基底外侧杏仁核内的食欲素一受体参与调节与大鼠偏头痛样状态相关的认知缺陷

摘要

目标

本研究探讨了基底外侧杏仁核 (BLA) 中食欲素一受体 (Orx1R) 在调节硝酸甘油 (NTG) 诱导的偏头痛样症状中的可能作用。此外，在成年雄性 Wistar 大鼠中评估了疼痛引起的学习和记忆能力的后续改变。

方法

每两天（9天）给予大鼠NTG（5mg / kg，ip）以诱导偏头痛样状态。用 BLA 内输注 Orx1R 拮抗剂 SB 334,867（10、20 和 40 nM/大鼠）或其载体 DMSO 治疗偏头痛动物。记录 NTG 引起的偏头痛症状 90 分钟。空间和被动回避性能分别通过莫里斯水迷宫 (MWM) 和穿梭箱任务进行评估。

结果

与对照组相比，NTG 产生了明显的偏头痛样症状，其特征是爬笼减少，抓头、冻结和面部修饰行为增加。SB 334,867 (40 nM/大鼠) 的 BLA 内输注显着降低了 NTG 治疗大鼠的笼子攀爬和增加面部修饰反应。此外，SB 334,867 的所有给药剂量均增加了 NTG 诱发的抓头和冻结行为。此外，NTG 在两项测试中都损害了学习和记忆的表现，这在注射 SB 334,867 (40 nM/大鼠) 后被夸大了。

结论

总体而言，这些数据为 BLA 内的食欲素系统在调节大鼠偏头痛伴认知能力下降方面提供了新的作用。