基于神经影像学技术的双语语码切换研究新进展

探究双语者对两种语言系统的加工过程，尤其是双语者有效地从一种语言切换到另一种语言即双语语码切换，是双语研 究领域的关键科学问题。随着神经影像学技术的快速发展，双语加工尤其是语码切换研究取得了重要的进展，但是对于双语语 码切换的内部产生机制，目前还没有一致的结论。从神经心理和影像学角度开展的双语切换研究可以从时间和空间两方面阐 明双语者进行语码切换的过程和大脑机制，为双语者语码切换的产生机制提供直接的证据。本文从事件相关电位技术、功能性 磁共振成像技术和脑磁图技术三个方面分析双语语码切换的研究，并对未来研究方向及其技术手段进行展望。

Progresses in the understanding of bilingual switching mechanisms based on neuroimaging techniques

Objective To investigate the effect of ulinastatin on the inflammatory mediators and their signaling pathways miR-146a/TLR4/NF-κB in rats with hemorrhagic shock. Methods Seventy-two SD rats were randomly assigned into shock without resuscitation group (SR group, n=24), acetated Ringer’s solution resuscitation group (AR group, n=24) and ulinastatin treatment group (n=24). In all the 3 groups hemorrhagic shock models were established by femoral artery bleeding (with the mean arterial pressure maintained at 30-40 mmHg) without resuscitation (in SR group) or with resuscitation (in AR and ulinastatin groups) using acetated Ringer’s solution for 30 min at 60 min after the onset of shock. At 1, 4, and 6 h after the shock onset or immediately after shock if the rats died, the lung tissues were taken for measurement of mRNA expressions of miR-146a, tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-4, IL-6 and IL-10 using real-time quantitative PCR and the protein expressions of TLR4, MyD88, IκB-α, p-IκB-α, NF-κB p65, IRAK4, p-IRAK4 (Thr345, Ser346), p-IRAK4 (Thr342) and TRAF6 using Western blotting. The lung histopathology of the rats was examined under optical microscope with HE staining. Results Compared with the SR group, the rats in the AR group showed slightly alleviated inflammatory infiltration in the lung tissues with significantly increased mRNA levels of miR-146a, IL-4 and IL-10 (P<0.05) and protein expressions of IκB-α, p-IRAK4 (Thr342) and p-IRAK4 (Thr345, ser346) (P<0.05), and decreased mRNA levels of TNF-α, IL-1 and IL-6 (P<0.05) and protein expressions of TLR4, MyD88, NF-κB p65, p-IκB-α, IRAK-4 and TRAF6 (P<0.05). Compared with those in AR group, the rats in ulinastatin group showed further alleviation of inflammatory lung tissue injury, with increased mRNA levels of miR-146a, IL-4 and IL-10 (P<0.01) and protein expressions of IκB-α, p-IRAK4 and p-IRAK4 (P<0.01) and decreased mRNA levels of TNF-α, IL-1 and IL-6 (P<0.01) and protein expressions of TLR4, MyD88, NF-κB p65, p-IκB-α, IRAK-4 and TRAF6 (P< 0.01). Conclusion Ulinastatin combined with acetated Ringer’s solution resuscitation alleviates lung inflammations in rats with hemorrhagic shock possibly by enhancing miR-146a expression to regulate TLR4/NF-κB signaling pathway through a negative feedback mechanism and thus modulate the balance of pro-inflammatory and anti-inflammatory factors.