中文摘要：

根据大鼠恐惧记忆形成前后不同时间段局部场电位的变化特征,研究恐惧记忆的形成对内侧前额叶皮层局部场电位的影响。选取健康成年雄性SD大鼠8只,利用脑立体定位仪将微丝电极植入到大鼠的内侧前额叶皮层;手术恢复后1周,在清醒状态下,通过穿梭恐惧记忆训练诱导出大鼠的恐惧记忆。借助Cerebus神经信号记录系统,记录大鼠在清醒状态下恐惧记忆形成前和恐惧记忆形成后6 h及1、2、3、4、5、6 d的内侧前额叶皮层的局部场电位信号,并采用Neuroexplorer软件分析局部场电位信号。以功率谱密度和功率百分比参数为指标,对恐惧记忆形成前后的总功率和不同时间状态下的各频段（δ：1-3 Hz,θ：4-7 Hz,α：8-13 Hz,β：14-30 Hz,γ：31-100 Hz）功率百分比进行方差分析。实验结果显示,恐惧记忆形成后6 h,θ波和β波的功率百分比较恐惧记忆形成前具有显著性差异（P=0.017,P=0.017）,θ波较恐惧记忆形成前功率百分比增加,β波较恐惧记忆形成前功率百分比降低;另外,恐惧记忆形成后第1、2 d,δ波的功率百分比较恐惧记忆形成前具有显著性差异（P=0.03,P=0.049）,γ波的功率百分比较恐惧记忆形成前具有显著性差异（P=0.013,P=0.019）。研究表明,恐惧记忆的形成对内侧前额叶皮层神经信息处理的模式产生显著性的影响。

英文摘要：

In this work,characteristics of local field potential before and after fear memory formation were studied to investigate the effects of fear memory formation on local field potential in rat medial prefrontal cortex.Eight healthy adult male SD rats were selected. The electrodes were implanted into the medial prefrontal cortex of the rats by stereotaxic apparatus. After one week,shuttle box test was used to induce fear memory in rats when rats were awake. The local field potential of rat medial prefrontal cortex was monitored by using Cerebus neural signals recording system,before and 6 h,1 d,2 d,3 d,4 d,5 d,6 d after fear memory formation. The Neuroexplorer software was introduced to analysis the local field potential. Power spectral density and power percentage of local field potentials were analyzed and compared with total power before and after the formation of fear memory and among different frequency bands（ δ： 1-3 Hz,θ： 4-7 Hz,α： 8-13 Hz,β： 14-30 Hz,γ： 31-100 Hz）. The results showed that the power percentage of θ and β at 6 h after fear memory formation was significantly different from that of before fear memory formation（ P = 0. 017, P = 0. 017）; The power percentage of θ was increased than that before fear memory formation. The power percentage of β was reduced than before fear memory formation. In addition,the power percentage of δ 1-2 days after fear memory formation was significantly different from that before fear memory formation（ P = 0. 03,P = 0. 049）. The powerpercentage of γ on 1 - 2 days after fear memory formation was significantly different from that before fear memory formation（ P = 0. 013,P = 0. 019）. These results indicated that activating mode of neural information processing in rat medial prefrontal cortex was significantly altered following fear memory formation.