摘要目的:探讨40 Hz、70 Hz频率闪光刺激对幼鼠的学习记忆与自主探究能力的影响。方法:27只SPF级19~21日龄雄性SD大鼠按照随机数字表法分为对照组(Ctr组)、40 Hz闪光刺激组(40 Hz组)、70 Hz闪光刺激组(70 Hz组)，每组9只。对照组大鼠不给予闪光刺激，40 Hz组与70 Hz组大鼠分别给予40 Hz和70 Hz的闪光刺激(1.5 h/d)，连续刺激39 d。采用Morris水迷宫实验评估大鼠的学习记忆能力，旷场实验评估大鼠的自主探究能力，尼氏染色观察大鼠海马CA1区尼氏体形态；运用电生理技术采集大鼠的视觉皮层区局部场电位(local field potentials，LFPs)用于验证闪光刺激诱发的神经振荡同步化效应。采用SPSS 23.0软件进行统计分析，正态分布的计量资料采用重复测量方差分析和单因素方差分析，进一步两两比较采用LSD检验和Tamhane检验；非正态分布计量资料采用Kruskal-Wallis检验。结果:(1)40 Hz与70 Hz频率闪光刺激可以有效引起健康幼鼠初级视觉皮层区神经振荡同步化。(2)重复测量方差分析结果显示，在Morris水迷宫定位航行阶段中，各组大鼠逃避潜伏期时间和组别交互作用不显著( F＝1.326， P>0.05)。逃避潜伏期的组别主效应不显著( F＝2.039， P>0.05)，时间主效应显著( F＝40.025， P<0.05)，随着学习天数的增加，各组幼鼠的逃避潜伏期显著减少。各组大鼠的运动总路程的时间和组别交互作用不显著( F＝2.029， P>0.079)，时间主效应显著( F＝32.052， P<0.05)，组别主效应不显著( F＝2.390， P>0.05)。随着学习天数的增加，各组大鼠的运动总路程显著缩短。Morris水迷宫实验第6天，3组幼鼠目标象限停留时间和穿越平台次数均差异无统计学意义( F＝2.511，0.802，均 P>0.05)。旷场实验结果显示，3组幼鼠的中心区域活动路程差异具有统计学意义( H＝8.935， P<0.05)，其中70 Hz组幼鼠的中心区域活动路程[3.80(2.25，6.93)m]明显长于40 Hz组[0.80(0.72，1.46)m， P<0.05)]。3组幼鼠的中心区域活动时间百分比差异具有统计学意义( H＝11.050， P<0.05)，其中70 Hz组幼鼠的中心区域活动时间百分比[3.20(2.43，8.30)]明显高于40 Hz组[0.95(0.37，1.06)， P<0.05]。(3)尼氏染色结果显示，3组幼鼠海马CA1区尼氏体均排列整齐紧密，周围间质均未见水肿，均未见明显的炎性细胞浸润。 结论:70 Hz频率闪光刺激可能会促进幼鼠的学习记忆能力和自主探究能力。

abstractsObjective:To investigate the effects of 40 Hz and 70 Hz frequency flash stimulation on the ability of learning memory and autonomous exploratory in young rats.Methods:Twenty-seven SPF grade male SD rats aged 19-21 days were divided into control group (Ctr group), 40 Hz group and 70 Hz group with 9 in each group according to the random number table.The rats in Ctr group were not given flash stimulation, while rats in the 40 Hz and 70 Hz group were received 40 Hz, 70 Hz flash stimulation (1.5 h/d for 39 days), respectively.The Morris water maze experiment was used to assess the learning and memory ability of rats, and the open field experiment was used to evaluate the ability of autonomous exploratory of rats.Nissl staining was used to assess the morphology of Nissl bodies in the hippocampus CA1 region of the rats.The local field potentials (LFPs) collected from the primary visual cortex (V1 area) region by electrophysiological experiments was used to verify the synchronization of flash evoked neural oscillations.SPSS 23.0 software was used for statistical analysis.The repeated measures ANOVA and one-way ANOVA were used to analyze normal distribution measurement data, and LSD and Tamhane tests were used for further pairwise comparison.The Kruskal-Wallis test was used for non-normal distribution measurement data.Results:(1) The flash stimulation of 40 Hz and 70 Hz both can effectively caused synchronization of neural oscillations in the primary visual cortex of healthy young rats.(2) The results of repeated measures ANOVA analysis showed that there was no interaction effect of grouping and time in the escape latency of young rats in the Morris water maze positioning navigation phase( F=1.326, P>0.05 ). The escape latency had time main effect ( F=40.025, P<0.05), but no grouping main effect ( F=2.039, P>0.05). With the increase of learning days, the escape latency of young rats in each group decreased significantly.There was no interaction effect of grouping and time in the total distance of young rats ( F=2.029, P>0.079). It had time main effect ( F=32.052, P<0.05), but not grouping main effect ( F=2.390, P>0.05) on total distance.With the increase of learning days, the total distance of young rats in each group significantly shortened.On the 6th day of the Morris water maze experiment, there was no statistically significant difference among groups in terms of time in the target quadrant and the number of crossing platforms ( F=2.511, 0.802, both P>0.05). The results of the open field experiment showed that the total distance traveled in the center of young rats in each group was statistically significant ( H=8.935, P<0.05), the total distance traveled in the center in the 70 Hz group (3.80 (2.25, 6.93) m)was significantly longer than that in the 40 Hz group (0.80 (0.72, 1.46) m), P<0.05). The percentage of time spent in the center was statistically significant in the three groups ( H=11.050, P<0.05). Young rats in the 70 Hz group spent significantly higher percentage of time in the center(3.20(2.43, 8.30)) than those in the 40 Hz group (0.95 (0.37, 1.06 ), P<0.05 ). (3) Nissl staining results showed that Nissl bodies in the hippocampal CA1 area of young rats in Ctr, 40 Hz and 70 Hz group were all arranged neatly and tightly, no edema was found in the surrounding stroma, and no obvious inflammatory cell infiltration was found. Conclusion:70 Hz frequency flash stimulation may promote the ability of learning memory and autonomous exploratory of young rats.