Motor behavior alterations are a shared hallmark of neurodegenerative diseases affecting motor circuits, such as amyotrophic lateral sclerosis (ALS), Parkinson’s, and Huntington’s diseases. In patients and transgenic animal models of amyotrophic lateral sclerosis fine movements controlled by distal muscles are the first to be affected, but its study and knowledge remain poorly understood, mainly because most of the tests used for describing the motor alterations are focused on the function of proximal muscles and gross movements. In this study we demonstrate that alterations of phalangeal fine movements can be quantitatively evaluated using a novel procedure designed by us, phalangeal tension recording test, which showed high sensitivity to detect such alterations. The evaluation was carried out during the MN degenerative process induced by the acute and chronic overactivation of AMPA receptors in the lumbar rat spinal cord, using previously described models. The new method allowed the quantification of significant alterations of the fine movements of the hindpaws phalanges when AMPA was infused in the lumbar segment controlling the distal muscles, but not when a more rostral spinal segment was infused, and these alterations were not detected by the rotarod or the stride tests. These changes occurred before the paralysis of the hindlimbs. Studying the early distal motor alterations before the total paralysis at late stages is essential for understanding the initial consequences of MN degeneration and therefore for designing new strategies for the control, treatment and prevention of MN diseases.

运动行为改变是影响运动回路的神经退行性疾病的共同特征，例如肌萎缩性侧索硬化症（ALS），帕金森氏症和亨廷顿氏病。在肌萎缩性侧索硬化症的患者和转基因动物模型中，首先受到远端肌肉控制的精细运动受到影响，但其研究和知识仍知之甚少，这主要是因为用于描述运动改变的大多数测试都集中在功能上。近端肌肉和总体运动。在这项研究中，我们证明可以使用由我们设计的新程序，指骨张力记录测试，对指骨精细运动的改变进行定量评估，该程序显示出检测此类改变的高度敏感性。使用先前描述的模型，在腰椎大鼠脊髓中AMPA受体的急性和慢性过度活化引起的MN退化过程中进行了评估。当在控制远端肌肉的腰椎节段中注入AMPA时，新方法可以量化后爪趾骨精细运动的显着变化，而在输注较具前额脊柱节段时则不能，并且旋转棒未检测到这些变化或大步测试。这些变化发生在后肢瘫痪之前。在晚期完全瘫痪之前研究早期远端运动改变对于理解MN变性的初始后果以及因此设计用于控制，治疗和预防MN疾病的新策略至关重要。