目的:探究小鼠外侧脊核(lateral spinal nucleus, LSN)至臂旁外侧核(lateral parabrachial nucleus, LPB)神经通路在痒觉信息传递中的作用。方法:选取18只C57BL/6J小鼠,采用随机数字表法分为激活组(LSN双侧注射DIO-hM3Dq病毒)、抑制组(LSN双侧注射DIO-hM4Di病毒)和对照组(LSN双侧注射DIO-mCherry病毒),每组6只。所有小鼠LPB双侧注射Cre-eGFP病毒,构建LSN-LPB特异性通路调控模型。病毒表达21 d后,所有小鼠先腹腔注射生理盐水,40 min后于颈部皮下分别注射氯喹、组胺或生理盐水,诱导急性痒或作为对照;完成上述行为检测后,同一批小鼠腹腔注射氯氮平,40 min后重复进行颈部皮下注射氯喹、组胺或生理盐水。每次注射后记录30 min内小鼠抓挠次数。结果:腹腔注射生理盐水后,三组间小鼠抓挠行为频次比较无显著差异(P＞0.05)。腹腔注射氯氮平后,激活组小鼠抓挠次数与对照组相比无显著差异(P＞0.05),抑制组小鼠在氯喹和组胺诱发下的抓挠行为显著低于对照组(P＜0.05)。结论:LSN-LPB通路参与调控急性痒觉信息传递,抑制该通路可有效缓解瘙痒行为,但激活该通路未引起明显效应。
Objective: To investigate the regulatory role of the lateral spinal nucleus (LSN)-lateral parabrachial nucleus (LPB) neural pathway in itch signaling transmission in mice. Methods: Totally 18 C57BL/6J mice were randomly divided into three groups (n=6 per group): an activation group (bilateral LSN injection of DIO-hM3Dq virus), an inhibition group (bilateral LSN injection of DIO-hM4Di virus), and a control group (bilateral LSN injection of DIO-mCherry virus). All mice received bilateral LPB injections of Cre-eGFP virus to establish a specific pathway modulation model. After 21 days of viral expression, all mice were first intraperitoneally injected with saline. 40 min later, acute itch was induced or controlled by subcutaneous neck injections of chloroquine, histamine, or saline. After all behavioral tests were completed, the same batch of mice received an intraperitoneal injection of clozapine. 40 min later, subcutaneous neck injections of chloroquine, histamine, or saline were administered again. Scratching bouts were recorded for 30 min after each injection. Results: After intraperitoneal saline injection, no significant difference in scratching behavior was observed among the three groups of C57BL/6J mice (P＞0.05). After intraperitoneal injection of clozapine, there was no significant difference in scratching behavior frequency between the activation group and the control group (P＞0.05). The scratching behavior of the inhibition group induced by chloroquine and histamine was significantly lower than that of the control group (P＜0.05). Conclusion: The LSN-LPB pathway is involved in regulating acute itch signal transmission. Inhibition of this pathway effectively alleviates itch-related behavior, while its activation does not produce a significant effect.
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