Ferrucci Michela, Lazzeri Gloria, Flaibani Marina, Biagioni Francesca, Cantini Federica, Madonna Michele, Bucci Domenico, Limanaqi Fiona, Soldani Paola, Fornai Francesco
Department of Translational Research and New Technologies in Medicine and Surgery, Human Anatomy, University of Pisa, Pisa, Italy.
Istituto di Ricovero e Cura a Carattere Scientifico, Neuromed, Pozzilli, Isernia, Italy.
Histol Histopathol. 2018 Oct;33(10):1021-1046. doi: 10.14670/HH-11-983. Epub 2018 Mar 14.
Counting motor neurons within the spinal cord and brainstem represents a seminal step to comprehend the anatomy and physiology of the final common pathway sourcing from the CNS. Motor neuron loss allows to assess the severity of motor neuron disorders while providing a tool to assess disease modifying effects. Counting motor neurons at first implies gold standard identification methods. In fact, motor neurons may occur within mixed nuclei housing a considerable amount of neurons other than motor neurons. In the present review, we analyse various approaches to count motor neurons emphasizing both the benefits and bias of each protocol. A special emphasis is placed on discussing automated stereology. When automated stereology does not take into account site-specificity and does not distinguish between heterogeneous neuronal populations, it may confound data making such a procedure a sort of "guide for the perplex". Thus, if on the one hand automated stereology improves our ability to quantify neuronal populations, it may also hide false positives/negatives in neuronal counts. For instance, classic staining for antigens such as SMI-32, SMN and ChAT, which are routinely considered to be specific for motor neurons, may also occur in other neuronal types of the spinal cord. Even site specificity within Lamina IX may be misleading due to neuronal populations having a size and shape typical of motor neurons. This is the case of spinal border cells, which often surpass the border of Lamina VII and intermingle with motor neurons of Lamina IX. The present article discusses the need to join automated stereology with a dedicated knowledge of each specific neuroanatomical setting.
对脊髓和脑干中的运动神经元进行计数是理解源自中枢神经系统的最后共同通路的解剖学和生理学的关键一步。运动神经元的丧失有助于评估运动神经元疾病的严重程度，同时提供一种评估疾病修饰作用的工具。首先，对运动神经元进行计数意味着采用金标准识别方法。事实上，运动神经元可能存在于包含大量非运动神经元的混合核中。在本综述中，我们分析了多种计数运动神经元的方法，强调了每种方法的优点和偏差。特别强调了对自动体视学的讨论。当自动体视学没有考虑到位点特异性且没有区分异质性神经元群体时，它可能会混淆数据，使这样的程序成为一种“困惑指南”。因此，一方面自动体视学提高了我们量化神经元群体的能力，但它也可能在神经元计数中隐藏假阳性/假阴性结果。例如，常规认为对运动神经元具有特异性的抗原（如SMI - 32、SMN和ChAT）的经典染色，也可能出现在脊髓的其他神经元类型中。即使是在脊髓灰质板层IX内的位点特异性也可能产生误导，因为存在具有典型运动神经元大小和形状的神经元群体。脊髓边界细胞就是这种情况，它们常常越过板层VII的边界并与板层IX的运动神经元混合在一起。本文讨论了将自动体视学与对每种特定神经解剖学背景的专门知识相结合的必要性。
