Köppen Jenny R, Stuebing Sarah L, Sieg Megan L, Blackwell Ashley A, Blankenship Philip A, Cheatwood Joseph L, Wallace Douglas G
Psychology Department Northern Illinois University De Kalb, IL, USA.
Department of Anatomy Southern Illinois University School of Medicine, Carbondale, Illinois, USA.
Behav Brain Res. 2016 Feb 15;299:97-104. doi: 10.1016/j.bbr.2015.11.021. Epub 2015 Dec 2.
Dementia of the Alzheimer's type (DAT) is a neurodegenerative disorder marked by loss of hippocampal cholinergic tone and significant memory impairments, specifically for memories acquired prior to disease onset. The nature of this relationship, however, remains debated. The current study used the string pulling task to evaluate the temporal effects of odor discrimination learning in animals with selective cholinergic lesions to determine the role of the septohippocampal cholinergic system in mnemonic function. Rats with 192-IgG-Saporin lesions to the medial septum had a higher number of correct responses in the reversal training when compared to sham rats, suggesting an inability to retrieve the previously learned discrimination; however, no temporal gradient was observed. Furthermore, there were no group differences when learning a novel odor discrimination, demonstrating the ability for all rats to form new memories. These results establish a role for the cholinergic medial septum projections in long-term memory retrieval. The current study provides a behavioral assessment technique to investigate factors that influence mnemonic deficits associated with rodent models of DAT.
阿尔茨海默病型痴呆（DAT）是一种神经退行性疾病，其特征是海马胆碱能张力丧失和显著的记忆障碍，特别是对疾病发作前获得的记忆。然而，这种关系的本质仍存在争议。当前的研究使用拉绳任务来评估嗅觉辨别学习对具有选择性胆碱能损伤的动物的时间效应，以确定隔海马胆碱能系统在记忆功能中的作用。与假手术大鼠相比，内侧隔区接受192-IgG-皂草素损伤的大鼠在反转训练中的正确反应次数更多，这表明它们无法检索先前学到的辨别能力；然而，未观察到时间梯度。此外，在学习新的嗅觉辨别时，各组之间没有差异，这表明所有大鼠都有形成新记忆的能力。这些结果确立了胆碱能内侧隔区投射在长期记忆检索中的作用。当前的研究提供了一种行为评估技术，以研究影响与DAT啮齿动物模型相关的记忆缺陷的因素。
