Roddick Kyle M, Roberts Amelia D, Schellinck Heather M, Brown Richard E
Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
Chem Senses. 2016 Jun;41(5):433-40. doi: 10.1093/chemse/bjw018. Epub 2016 Mar 11.
Deficits in odor identification and detection are early symptoms of Alzheimer's disease (AD). Two transgenic mouse models of AD, the 5XFAD and the 3×Tg-AD mice and their wildtype controls, were assessed for olfactory detection with decreasing concentrations of ethyl acetate in a go no-go operant olfactometer task at 6 months of age. For both the 5XFAD and their B6SJLF1 wildtype littermates, females made fewer errors in detecting the ethyl acetate than males on all but the lowest odor concentrations. Female 5XFAD mice performed slightly better than their female wildtype littermates on the higher odor concentrations, though not at the lowest concentration. The 3×Tg-AD females showed decreased olfactory detection compared with their wildtype B6129S1 controls, whereas there was no difference in the males. Therefore, although the 5XFAD mice showed no olfactory detection deficits, female 3×Tg-AD mice had impaired olfactory detection at low odor concentrations but males did not. This difference in odor detection should be considered in studies of olfactory learning and memory, as differences in performance may be due to sensory rather than cognitive factors, though detection seems unimpaired at high odor concentrations.
气味识别和检测缺陷是阿尔茨海默病（AD）的早期症状。在6个月大时，使用递减浓度的乙酸乙酯，通过一种非连续操作嗅觉计任务，对两种AD转基因小鼠模型（5XFAD和3×Tg-AD小鼠）及其野生型对照进行嗅觉检测评估。对于5XFAD小鼠及其B6SJLF1野生型同窝小鼠，除了最低气味浓度外，在检测乙酸乙酯时，雌性小鼠的错误比雄性小鼠少。在较高气味浓度下，雌性5XFAD小鼠的表现略优于其雌性野生型同窝小鼠，但在最低浓度下则不然。与野生型B6129S1对照相比，3×Tg-AD雌性小鼠的嗅觉检测能力下降，而雄性小鼠则没有差异。因此，尽管5XFAD小鼠没有表现出嗅觉检测缺陷，但雌性3×Tg-AD小鼠在低气味浓度下嗅觉检测受损，而雄性则没有。在嗅觉学习和记忆研究中应考虑这种气味检测差异，因为表现差异可能是由于感觉因素而非认知因素，尽管在高气味浓度下检测似乎未受损。
