早期丰富环境刺激对仔鼠学习记忆能力及海马突触可塑性的影响

The effect of early enriched environment stimulation on learning and memory and synaptic plasticity of hippocampus in the newborn rats

目的观察早期丰富环境(early enriched environment,EEE)刺激对仔鼠学习记忆能力及海马突触可塑性的影响。方法2014年5—11月将健康1月龄雄性Wistar大鼠随机分为对照组和丰富环境组各8只。对照组大鼠饲养于普通鼠笼中,每笼4只;丰富环境组大鼠饲养于丰富环境模型鼠笼中,每笼8只,连续6个月。实验结束后,测定大鼠的学习记忆能力并诱导海马CA1区的长时程增强(long-term potentiation,LTP)。计量资料比较采用t检验,P<0.05为差异有统计学意义。结果丰富环境组大鼠在Y迷宫实验中达标所需训练次数为(26.3±3.1)次,错误反应次数为(12.5±1.3)次,明显少于对照组的[(31.8±4.8)、(14.9±2.1)次],差异均有统计学意义(均P<0.05);且丰富环境组群峰电位(population spike,PS)增幅[(162.15±2.40)%]高于对照组[(146.41±2.75)%],差异有统计学意义(P<0.05)。结论 EEE刺激可以提高仔鼠的学习记忆能力,其作用机制可能与提高大鼠海马CA1区的LTP,明显改善突触的可塑性有关。

Objective To study the effect of early enriched environment stimulation on learning and memory and synaptic plasticity of hippocampus in the newborn rats.Methods Healthy 1-month-old male Wistar rats were randomly divided into 2groups： control group and rich environment group,8 rats in each group from May to December in 2014.Rats in control group were reared in ordinary cage for 6 months,4 rats in each cage.Rats in rich environment group were raised in a rich environment model rat cage for 6 months,8 rats in each cage.Then,the learning and memory ability of rats were examined and long term potentiation（LTP） in hippocampal CA1 region were detected.Measurement data was processed by t test,P〈0.05 was considered statistically significant.Results Compared with the control group,training times required to achieve targets and error response times [（26.3±3.1）,（12.5±1.3）] were decreased significantly in the rich environment group[（31.8±4.8）,（14.9±2.1）]（P〈0.05）.Population spike（PS）amplitude [（162.15±2.40）%] in the rich environment group was significantly higher than that of the control group [（146.41±2.75）%]（P〈0.05）.Conclusion Early enriched environment stimulation could improve the learning and memory capacity in the newborn rats,which may be closely related to enhancement of LTP in CA1 area of hippocampus,and significant improvement of synaptic plasticity.