Certain neuronal populations, including basal forebrain cholinergic neurons (BFCN) and noradrenergic neurons of the locus coeruleus (LC), are selectively vulnerable to pathology and loss early in the course of aging and Alzheimer's disease (AD). Human BFCN show substantial loss of the calcium-binding protein (CBP), calbindin-D28K (CB), during normal aging, which is associated with formation of neurofibrillary tangles and BFCN loss in AD. Here we determined if, similar to the BFCN, LC neurons contain CB or the other 2 ubiquitous CBPs parvalbumin and calretinin, and whether these proteins display an age-related loss from LC neurons. Immunostaining for CBP and tyrosine hydroxylase, a marker of catecholaminergic neurons, was used in sections from the LC of young and aged human brains. Parvalbumin and calretinin immunoreactivities were completely absent from human LC neurons. A subpopulation of LC neurons (~10%) contained CB immunoreactivity. Quantitative analysis revealed no age-related loss of CB from LC neurons. Thus, unlike the BFCN, age-related loss of CB does not figure prominently in the selective vulnerability of LC neurons to degeneration in AD.

中文翻译：

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年轻和老年人类蓝斑中的 Calbindin-D28K、小清蛋白和钙视网膜蛋白

某些神经元群，包括基底前脑胆碱能神经元 (BFCN) 和蓝斑去甲肾上腺素能神经元 (LC)，在衰老和阿尔茨海默病 (AD) 过程的早期选择性地容易受到病理和损失的影响。在正常衰老过程中，人类 BFCN 显示出钙结合蛋白 (CBP)、钙结合蛋白-D28K (CB) 的大量损失，这与 AD 中神经原纤维缠结的形成和 BFCN 损失有关。在这里，我们确定与 BFCN 类似，LC 神经元是否含有 CB 或其他 2 种普遍存在的 CBP 小清蛋白和钙结合蛋白，以及这些蛋白质是否表现出 LC 神经元与年龄相关的损失。CBP 和酪氨酸羟化酶（儿茶酚胺能神经元的标记物）的免疫染色被用于年轻和老年人类大脑 LC 切片中。人 LC 神经元完全不存在小白蛋白和钙结合蛋白免疫反应性。LC 神经元亚群 (~10%) 含有 CB 免疫反应性。定量分析显示 LC 神经元的 CB 没有与年龄相关的损失。因此，与 BFCN 不同，与年龄相关的 CB 丧失在 AD 中 LC 神经元对退化的选择性脆弱性中并不显着。