Retrieval deficit of long-term memory is a cardinal symptom of dementia and has been proposed to associate with abnormalities in the central cholinergic system. Difficulty in the retrieval of memory is experienced by healthy individuals and not limited to patients with neurological disorders that result in forgetfulness. The difficulty of retrieving memories is associated with various factors, such as how often the event was experienced or remembered, but it is unclear how the cholinergic system plays a role in the retrieval of memory formed by a daily routine (accumulated experience). To investigate this point, we trained rats moderately (for a week) or extensively (for a month) to detect a visual cue in a two-alternative forced-choice task. First, we confirmed the well-established memory in the extensively trained group was more resistant to the retrieval problem than recently acquired memory in the moderately trained group. Next, we tested the effect of a cholinesterase inhibitor, donepezil, on the retrieval of memory after a long no-task period in extensively trained rats. Pre-administration of donepezil improved performance and reduced the latency of task initiation compared to the saline-treated group. Finally, we lesioned cholinergic neurons of the nucleus basalis magnocellularis (NBM), which project to the entire neocortex, by injecting the cholinergic toxin 192 IgG-saporin. NBM-lesioned rats showed severely impaired task initiation and performance. These abilities recovered as the trials progressed, though they never reached the level observed in rats with intact NBM. These results suggest that acetylcholine released from the NBM contributes to the retrieval of well-established memory developed by a daily routine.

长期记忆的检索缺陷是痴呆的主要症状，并且已被提出与中枢胆碱能系统的异常有关。恢复记忆的困难是健康个体所经历的，并且不仅限于导致健忘的神经系统疾病的患者。检索记忆的难度与各种因素有关，例如经历或记住事件的频率，但尚不清楚胆碱能系统如何在日常生活（累积经验）形成的记忆检索中发挥作用。为了研究这一点，我们对大鼠进行了适度（一周）或广泛（一个月）的训练，以检测两种选择的强制选择任务中的视觉线索。第一的，我们证实，与中等训练组最近获得的记忆相比，在广泛训练组中建立良好的记忆更能抵抗检索问题。接下来，我们测试了胆碱酯酶抑制剂多奈哌齐对经过广泛训练的大鼠长时间无任务后记忆恢复的影响。与盐水治疗组相比，多奈哌齐的预给药提高了性能并减少了任务启动的延迟。最后，我们通过注射胆碱能毒素 192 IgG-皂草素损伤了投射到整个新皮质的基底核 (NBM) 的胆碱能神经元。NBM 损伤大鼠表现出严重受损的任务启动和性能。这些能力随着试验的进行而恢复，尽管它们从未达到在具有完整 NBM 的大鼠中观察到的水平。