School of Medicine, The Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin, China.
Int J Nanomedicine. 2011;6:1453-61. doi: 10.2147/IJN.S18507. Epub 2011 Jul 11.
This study focused on the effects of zinc oxide nanoparticles (nano-ZnO) on spatial learning and memory and synaptic plasticity in the hippocampus of young rats, and tried to interpret the underlying mechanism. Rats were randomly divided into four groups. Nano-ZnO and phosphate-buffered saline were administered in 4-week-old rats for 8 weeks. Subsequently, performance in Morris water maze (MWM) was determined, and then long-term potentiation (LTP) and depotentiation were measured in the perforant pathway to dentate gyrus (DG) in anesthetized rats. The data showed that, (1) in MWM, the escape latency was prolonged in the nano-ZnO group and, (2) LTP was significantly enhanced in the nano-ZnO group, while depotentiation was barely influenced in the DG region of the nano-ZnO group. This bidirectional effect on long-term synaptic plasticity broke the balance between stability and flexibility of cognition. The spatial learning and memory ability was attenuated by the alteration of synaptic plasticity in nano-ZnO-treated rats.
本研究旨在探讨氧化锌纳米粒子（nano-ZnO）对幼鼠海马空间学习和记忆及突触可塑性的影响，并试图解释其潜在机制。将大鼠随机分为四组。4 周龄大鼠给予 nano-ZnO 和磷酸盐缓冲液，连续给药 8 周。随后，通过 Morris 水迷宫（MWM）确定大鼠的行为表现，然后在麻醉大鼠中测量穿通纤维到齿状回（DG）的长时程增强（LTP）和去极化。结果显示：（1）MWM 中，nano-ZnO 组大鼠逃避潜伏期延长；（2）nano-ZnO 组大鼠 LTP 明显增强，而 DG 区去极化变化不明显。这种对长时程突触可塑性的双向影响打破了认知稳定性和灵活性之间的平衡。nano-ZnO 处理大鼠的突触可塑性改变导致其空间学习和记忆能力减弱。
