School of Biomedical Sciences and Pharmacy, University of Newcastle, Callaghan, NSW 2308, Australia.
Curr Drug Targets. 2013 Oct;14(11):1262-76. doi: 10.2174/13894501113149990208.
Traditionally, microglia have been considered to act as macrophages of the central nervous system. While this concept still remains true it is also becoming increasingly apparent that microglia are involved in a host of nonimmunological activities, such as monitoring synaptic function and maintaining synaptic integrity. It has also become apparent that microglia are exquisitely sensitive to perturbation by environmental challenges. The aim of the current review is to critically examine the now substantial literature that has developed around the ability of acute, sub-chronic and chronic stressors to alter microglial structure and function. The vast majority of studies have demonstrated that stress promotes significant structural remodelling of microglia, and can enhance the release of pro-inflammatory cytokines from microglia. Mechanistically, many of these effects appear to be driven by traditional stress-linked signalling molecules, namely corticosterone and norepinephrine. The specific effects of these signalling molecules are, however, complex as they can exert both inhibitory and suppressive effects on microglia depending upon the duration and intensity of exposure. Importantly, research has now shown that these stress-induced microglial alterations, rather than being epiphenomena, have broader behavioural implications, with the available evidence implicating microglia in directly regulating certain aspects of cognitive function and emotional regulation.
传统上，小胶质细胞被认为是中枢神经系统的巨噬细胞。虽然这个概念仍然成立，但越来越明显的是，小胶质细胞参与了许多非免疫活动，如监测突触功能和维持突触完整性。同样明显的是，小胶质细胞对环境挑战的干扰非常敏感。本综述的目的是批判性地检查目前围绕急性、亚慢性和慢性应激源改变小胶质细胞结构和功能的大量文献。绝大多数研究表明，应激会促进小胶质细胞的显著结构重塑，并增强小胶质细胞释放促炎细胞因子。从机制上讲，这些作用中的许多似乎是由传统的应激相关信号分子，即皮质酮和去甲肾上腺素驱动的。然而，这些信号分子的具体作用很复杂，因为它们对小胶质细胞的作用既可以是抑制性的，也可以是抑制性的，这取决于暴露的持续时间和强度。重要的是，研究现在表明，这些应激诱导的小胶质细胞改变，而不是偶然现象，具有更广泛的行为意义，现有证据表明小胶质细胞直接调节认知功能和情绪调节的某些方面。
