The deposition of amyloid-β peptides in the form of extracellular plaques and neuronal degeneration belong to the hallmark features of Alzheimer's disease (AD). In addition, impaired calcium homeostasis and altered levels in calcium-binding proteins seem to be associated with the disease process. In this study, calretinin- (CR) and parvalbumin- (PV) positive gamma-aminobutyric acid-producing (GABAergic) interneurons were quantified in different hippocampal subfields of 12-month-old wild-type mice, as well as in the transgenic AD mouse models 5XFAD and Tg4-42. While, in comparison with wild-type mice, CR-positive interneurons were mainly reduced in the CA1 and CA2/3 regions in plaque-bearing 5XFAD mice, PV-positive interneurons were reduced in all analyzed subfields including the dentate gyrus. No reduction in CR- and PV-positive interneuron numbers was detected in the non-plaque-forming Tg4-42 mouse, although this model has been previously demonstrated to harbor a massive loss of CA1 pyramidal neurons. These results provide information about hippocampal interneuron numbers in two relevant AD mouse models, suggesting that interneuron loss in this brain region may be related to extracellular amyloid burden.

中文翻译：

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5XFAD 阿尔茨海默病小鼠模型中海马钙视网膜蛋白和小清蛋白中间神经元的丢失。

淀粉样蛋白 β 肽以细胞外斑块和神经元变性的形式沉积，属于阿尔茨海默病 (AD) 的标志性特征。此外，钙稳态受损和钙结合蛋白水平改变似乎与疾病过程有关。在这项研究中，在 12 个月大的野生型小鼠的不同海马亚区以及转基因 AD 中量化了钙视网膜蛋白 (CR) 和小清蛋白 (PV) 阳性产生 γ-氨基丁酸 (GABAergic) 的中间神经元小鼠模型 5XFAD 和 Tg4-42。与野生型小鼠相比，携带斑块的 5XFAD 小鼠的 CA1 和 CA2/3 区域的 CR 阳性中间神经元主要减少，而包括齿状回在内的所有分析亚区的 PV 阳性中间神经元均减少。在未形成斑块的 Tg4-42 小鼠中未检测到 CR 和 PV 阳性中间神经元数量的减少，尽管该模型先前已被证明具有 CA1 锥体神经元的大量损失。这些结果提供了两个相关 AD 小鼠模型中海马中间神经元数量的信息，表明该大脑区域的中间神经元丢失可能与细胞外淀粉样蛋白负荷有关。