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目的:探讨前额叶皮质区小胶质细胞活化对卒中后抑郁小鼠远期空间记忆功能的影响。方法:取48只C57BL/6雄性小鼠按照随机数字表法分为假手术组、卒中组、卒中后抑郁组和抑郁组，另取36只小鼠按照随机数字表法分为溶剂组、恩诺沙星组和米诺环素组，每组12只。采用大脑中动脉栓塞(middle cerebral artery occlusion，MCAO)方法建立卒中模型，强迫游泳方法建立抑郁模型，卒中后抑郁模型小鼠先进行MCAO，卒中后第4天进行强迫游泳建模。恩诺沙星组和米诺环素组小鼠分别于卒中后第5天连续14 d通过注射恩诺沙星和米诺环素治疗。利用强迫游泳与糖水偏爱实验评估各组小鼠的抑郁情况，Morris水迷宫实验检测各组小鼠的空间记忆功能，尼氏染色法和免疫荧光染色法检测各组小鼠神经元功能和小胶质细胞活化数量和类型，并通过Western blot法检测各组小鼠炎性因子IL-6和IL-1β的表达。采用GraphPad Prism 8.0.1统计软件进行统计分析，多组间比较采用单因素方差分析，进一步两两比较采用SNK-n q检验。n 结果:(1)假手术组、卒中组、卒中后抑郁组和抑郁组4组小鼠抑郁、学习记忆、神经元损伤、小胶质细胞活化、炎性因子等指标均差异有统计学意义(n F＝43.58~255.70，均n P<0.05)。与卒中组比较，卒中后抑郁组小鼠漂浮不动时间长[(222.70±29.12)s，(79.25±46.78)s，n P<0.05]，糖水偏爱率明显低[(49.44±6.19)%，(84.49±4.73)%，n P<0.05]，校正后站台接近估计平均值高[(125.00±9.95)mm，(96.79±12.57)mm，n P<0.05]，尼氏小体表达量少[(53.50±15.78)个/mmn 2，(85.67±17.52)个/mmn 2，n P<0.05]，神经元NeuN阳性表达率低[(29.78±3.70)%，(45.73±4.51)%，n P<0.05]，M1型小胶质细胞数量百分比高[(75.55±8.84)%，(58.19±5.69)%，n P<0.05]，M2型小胶质细胞数量百分比低[(43.46±5.11)%，(57.14±5.40)%，n P<0.05]，IL-6 [(1.14±0.03)，(0.94±0.05)，n P<0.05]和IL-1β[(1.17±0.03)，(0.56±0.04)，n P<0.05]表达量均显著上调。(2)溶剂组、恩诺沙星组和米诺环素组3组小鼠抑郁、学习记忆、神经元损伤、小胶质细胞活化、炎性因子等指标均差异有统计学意义(n F＝7.13~94.35，均n P<0.05)。与恩诺沙星组小鼠比较，米诺环素组小鼠漂浮不动时间短[(169.30±13.04)s，(224.30±22.60)s，n P<0.05]，糖水偏爱率高[(62.81±7.75)%，(47.71±8.11)%，n P<0.05]，水迷宫校正后站台接近估计平均值低[(97.66±14.56)mm，(120.20±12.08)mm，n P<0.05]，尼氏小体表达量多[(80.17±10.55)个/mmn 2，(52.00±8.94)个/mmn 2，n P<0.05]，神经元NeuN阳性表达率高[(45.04±3.62)%，(28.88±4.50)%，n P<0.05]，Iba-1表达量低[(97.33±10.67)个/mmn 2，(112.50±6.54)个/mmn 2，n P<0.05]，M1型小胶质细胞数量百分比低[(54.43±5.22)%，(73.82±6.88)%，n P<0.05]，M2型小胶质细胞数量百分比高[(51.86±6.22)%，(36.30±5.72)%，n P<0.05]，IL-6[(0.75±0.06)，(1.21±0.07)，n P<0.05]和IL-1β[(0.61±0.06)，(1.09±0.09)，n P<0.05]表达量均较低。n 结论:卒中后抑郁小鼠远期空间记忆能力受损加重，可能与PFC区M1型小胶质细胞活化增加造成的神经元受损相关，米诺环素通过抑制M1型小胶质细胞能有效改善小鼠的空间记忆能力。“,”Objective:To investigate the effect of activation of microglia in prefrontal cortex on long-term spatial memory in post-stroke depression mice.Methods:Forty-eight male C57BL/6 mice were divided into sham operation group, stroke group, post-stroke depression group and depression group according to the random number table method with 12 in each group, and 36 mice were divided into solvent group, enrofloxacin group and minocycline group according to the random number table method with 12 in each group.Middle cerebral artery occlusion (MCAO) was use to establish the stroke model, and forced swimming was used to establish the depression model.The post-stroke depression model mice were received MCAO first and then received forced swimming on the 4th day after stroke to establish the model.Mice in enrofloxacin group and minocycline group were treated with enrofloxacin and minocycline injection once a clay for 14 days from the 5th day after stroke, respectively.Forced swimming test and sugar water preference test were used to evaluate the depression of mice in each group, Morris water maze test was used to detect the spatial memory function of mice in each group, and Nissl staining and immunofluorescence staining were used to detect the neuronal function and the number and type of microglia activation.The expression of inflammatory cytokines IL-6 and IL-1β were detected by Western blot.GraphPad Prism 8.0.1 statistical software was used for statistical analysis.The single factor variance analysis was used to compare the difference among multiple groups, and pairwise comparison was performed with SNK-n q test.n Results:(1) There were statistically significant differences in depression, learning and memory, neuron damage, activation of microglia, inflammatory factors and other indicators in sham operation group, stroke group, post-stroke depression group and depression group (n F=43.58-255.70, all n P<0.05). Compared with stroke group, post-stroke depression group had longer floating immobility time ((222.70±29.12) s, (79.25±46.78) s,n P<0.05), the preference rate of sugar water was significantly lower ( (49.44±6.19) %, (84.49±4.73) %,n P<0.05), and the average value of platform approach after correction was higher((125.00±9.95) mm, (96.79±12.57) mm,n P<0.05), Nissl bodies expression was lower ((53.50±15.78) cells /mmn 2, (85.67±17.52) cells /mmn 2, n P<0.05), NeuN positive expression rate was lower ((29.78±3.70) %, (45.73±4.51) %,n P<0.05), the percent of M1 microglia expression was significantly higher ((75.55±8.84) %, (58.19±5.69) %,n P<0.05), the percent of M2 microglia expression was lower ((43.46±5.11)%, (57.14±5.40)%,n P<0.05), and the expression levels of IL-6 ((1.14±0.03), (0.94±0.05),n P<0.05) and IL-1β((1.17±0.03), (0.56±0.04),n P<0.05) were significantly higher.(2) Depression, learning and memory, neuron injury, activation of microglia, inflammatory factors and other indicators of mice in solvent group, enrofloxacin group and minocycline group were significantly different (n F=7.13-94.35, all n P<0.05). Compared with enrofloxacin group, mice in minocycline group had shorter floating immobility time ((169.30±13.04) s, (224.30±22.60) s,n P<0.05) and higher sugar water preference rate ((62.81±7.75) %, (47.71±8.11) %,n P<0.05), the mean value of platform approach estimation after water maze correction was lower ((97.66±14.56) mm, (120.20±12.08) mm,n P<0.05), and the expression level of Nissl bodies was higher ((80.17±10.55) cells /mmn 2, (52.00±8.94) cells /mmn 2, n P<0.05), NeuN expression rate was high ((45.04±3.62) %, (28.88±4.50) %,n P<0.05), Iba-1 expression was lower ((97.33±10.67) cells/mmn 2, (112.50±6.54)cells/mmn 2, n P<0.05), the percent of M1 microglia expression was lower ((54.43±5.22) %, (73.82±6.88) %,n P<0.05), and the percent of M2 microglia expression was significantly higher ((51.86±6.22) %, (36.30±5.72) %,n P<0.05). The expression levels of IL-6 ((0.75±0.06), (1.21±0.07),n P<0.05) and IL-1β ((0.61±0.06) (1.09±0.09),n P<0.05) were lower.n Conclusion:The long-term spatial memory impairment of post-stroke depression mice is aggravated, which is related to the neuron damage caused by increased activation of M1 microglia in PFC area.Inhibition of M1 microglia by minocycline can effectively improve the spatial memory ability of mice.