Departments of Dermatology, Nippon Medical School, Tokyo, Japan.
J Dermatol. 2011 Jun;38(6):553-61. doi: 10.1111/j.1346-8138.2010.01045.x. Epub 2010 Nov 2.
Inflammatory skin disorder aggravates when a horrific memory is evoked, but the mechanism of this effect is unclear. The objective of the present study was to examine the effects of evocation of a horrific memory on the skin and mast cells in an animal model. A sound stimulus linked to an electric shock was given to C57BL/6 mice (7-week old, males). One, 3 and 5 days later, the mice received the sound stimulus again. The reactions of mice that received the initial sound stimulus were compared with those of mice that did not receive the initial stimulus. A freezing phenomenon was observed when the sound stimulus was given to mice that received the initial stimulus, which indicated evocation of a past memory of fear. The degranulation rate of dermal mast cells and the length of substance P (SP)-positive nerve fibers of the skin significantly increased on days 1 and 3, the SP level decreased significantly, and the number of SP-expressing cells in the dorsal root ganglion significantly increased on day 1. These findings suggest that prior experience of severe stress linked to a stimulus subsequently evokes fear associated with the same stimulus and results in activation of dermal mast cells and skin nerves.
当唤起可怕的记忆时，炎症性皮肤疾病会加重，但这种效应的机制尚不清楚。本研究的目的是在动物模型中检查唤起可怕记忆对皮肤和肥大细胞的影响。向 C57BL/6 小鼠（7 周龄，雄性）给予与电击相关的声音刺激。1、3 和 5 天后，再次向这些小鼠给予声音刺激。比较了初次接受声音刺激的小鼠与未接受初始刺激的小鼠的反应。当向接受初始刺激的小鼠给予声音刺激时，观察到冻结现象，这表明对过去恐惧记忆的唤起。在第 1 天和第 3 天，皮肤真皮肥大细胞脱颗粒率和 P 物质（SP）阳性神经纤维的长度显著增加，SP 水平显著降低，背根神经节中表达 SP 的细胞数量显著增加。这些发现表明，与刺激相关的先前严重应激经历随后会唤起与相同刺激相关的恐惧，并导致皮肤肥大细胞和皮肤神经的激活。
