Xing Hong, Girdhar Pallavi, Liu Yuning, Yokoi Fumiaki, Vaillancourt David E, Li Yuqing
Norman Fixel Institute of Neurological Diseases, McKnight Brain Institute, and Department of Neurology, College of Medicine, University of Florida, Gainesville, FL 32610-0236, USA.
Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, USA.
Dystonia. 2025;4. doi: 10.3389/dyst.2025.14148. Epub 2025 Jan 29.
DYT1 dystonia is an inherited early-onset generalized dystonia characterized by sustained muscle contractions causing abnormal, repetitive movements or postures. Most DYT1 patients have a heterozygous trinucleotide GAG deletion () in , coding for torsinA. heterozygous ΔGAG knock-in (KI) mice or global KI mice show motor deficits and abnormal Purkinje cell firing. However, Purkinje cell-specific heterozygous ΔGAG conditional KI mice (Pcp2-KI) show improved motor performance, reduced sensory-evoked brain activation in the striatum and midbrain, and reduced functional connectivity of the striatum with the anterior medulla. Whether Pcp2-KI mice show similar abnormal Purkinje cell firing as the global KI mice, suggesting a cell-autonomous effect causes the abnormal Purkinje cell firing in the global KI mice, is unknown. We used acute cerebellar slice recording in Pcp2-KI mice to address this issue. The Pcp2-KI mice exhibited no changes in spontaneous firing and intrinsic excitability compared to the control mice. While membrane properties were largely unchanged, the resting membrane potential was slightly hyperpolarized, which was associated with decreased baseline excitability. Our results suggest that the abnormal Purkinje cell firing in the global KI mice was not cell-autonomous and was caused by physiological changes elsewhere in the brain circuits. Our results also contribute to the ongoing research of how basal ganglia and cerebellum interact to influence motor control in normal states and movement disorders.
DYT1肌张力障碍是一种遗传性早发性全身性肌张力障碍,其特征为持续的肌肉收缩,导致异常的重复性运动或姿势。大多数DYT1患者在编码torsinA的基因中有一个杂合的三核苷酸GAG缺失()。杂合的ΔGAG敲入(KI)小鼠或全身性KI小鼠表现出运动缺陷和浦肯野细胞放电异常。然而,浦肯野细胞特异性杂合ΔGAG条件性KI小鼠(Pcp2-KI)表现出运动性能改善、纹状体和中脑感觉诱发脑激活减少,以及纹状体与延髓前部的功能连接减少。Pcp2-KI小鼠是否表现出与全身性KI小鼠类似的异常浦肯野细胞放电,提示细胞自主效应导致全身性KI小鼠浦肯野细胞放电异常,目前尚不清楚。我们使用Pcp2-KI小鼠的急性小脑切片记录来解决这个问题。与对照小鼠相比,Pcp2-KI小鼠的自发放电和内在兴奋性没有变化。虽然膜特性基本未变,但静息膜电位略有超极化,这与基线兴奋性降低有关。我们的结果表明,全身性KI小鼠中异常的浦肯野细胞放电不是细胞自主的,而是由脑回路其他部位的生理变化引起的。我们的结果也有助于正在进行的关于基底神经节和小脑如何相互作用以影响正常状态和运动障碍中的运动控制的研究。