Yi Jee Hyun, Park Hye Jin, Kim Byeong C, Kim Dong Hyun, Ryu Jong Hoon
School of Clinical Sciences, Faculty of Medicine and Dentistry, University of Bristol, Bristol, UK.
Department of Medicinal Biotechnology, College of Health Sciences, Dong-A University, Busan 604-714, Republic of Korea; Dong-A Anti-aging Research Center, Dong-A University, Busan 604-714, Republic of Korea.
Behav Brain Res. 2016 Jan 15;297:141-9. doi: 10.1016/j.bbr.2015.10.018. Epub 2015 Oct 20.
The hippocampus is a key region responsible for processing spatial information. However, the role of the hippocampus in non-spatial recognition memory is still controversial. In the present study, we performed hippocampal lesioning to address this controversy. The hippocampi of mice were disrupted with bilateral cytotoxic lesions, and standard object recognition (non-spatial) and object location recognition (spatial) were tested. In the habituation period, mice with hippocampal lesions needed a significantly longer time to fully habituate to the test box. Interestingly, after 4 days of habituation (insufficient habituation), the recognition index was similar in the sham and hippocampal lesion groups. However, exploration time was significantly shorter in mice with hippocampal lesions compared with that in control mice. Interestingly, if mice were subjected to a 10-days-long period of habituation (full habituation), the recognition index was significantly lower in mice with hippocampal lesions compared with that in control mice; however, total exploration time was similar in both groups. Furthermore, the object recognition test after full habituation occluded hippocampal long-term potentiation, a cellular model of memory. These results indicate that sufficient habituation is required to observe the effects of hippocampal lesions on object recognition memory.
海马体是负责处理空间信息的关键区域。然而，海马体在非空间识别记忆中的作用仍存在争议。在本研究中，我们进行了海马体损伤实验以解决这一争议。通过双侧细胞毒性损伤破坏小鼠的海马体，并测试标准物体识别（非空间）和物体位置识别（空间）。在适应期，海马体损伤的小鼠需要显著更长的时间才能完全适应测试箱。有趣的是，在4天的适应期（适应不足）后，假手术组和海马体损伤组的识别指数相似。然而，与对照小鼠相比，海马体损伤小鼠的探索时间显著缩短。有趣的是，如果小鼠经历为期10天的适应期（完全适应），与对照小鼠相比，海马体损伤小鼠的识别指数显著降低；然而，两组的总探索时间相似。此外，完全适应后的物体识别测试阻断了海马体长时程增强，这是一种记忆的细胞模型。这些结果表明，需要足够的适应期才能观察到海马体损伤对物体识别记忆的影响。
