Quilgars Camille, Boué-Grabot Eric, de Deurwaerdère Philippe, Cazalets Jean-René, Perrin Florence E, Bertrand Sandrine S
Université de Bordeaux, CNRS, INCIA, UMR 5287, Bordeaux, France.
Université de Bordeaux, CNRS, Institut des Maladies Neurodégénératives, UMR 5293, Bordeaux, France.
PLoS Biol. 2025 Apr 21;23(4):e3003153. doi: 10.1371/journal.pbio.3003153. eCollection 2025 Apr.
In this study, we aimed to determine the impact of an increase in motor activity during the highly plastic period of development of the motor spinal cord and hindlimb muscles in newborn mice. A swim training regimen, consisting of two sessions per day for two days, was conducted in 1 and 2-day-old (P1, P2) pups. P3-trained pups showed a faster acquisition of a four-limb swimming pattern, accompanied by dysregulated gene expression in the lateral motor column, alterations in the intrinsic membrane properties of motoneurons (MNs) and synaptic plasticity, as well as increased axonal myelination in motor regions of the spinal cord. Network-level changes were also observed, as synaptic events in MNs and spinal noradrenaline and serotonin contents were modified by training. At the muscular level, slight changes in neuromuscular junction morphology and myosin subtype expression in hindlimb muscles were observed in trained animals. Furthermore, the temporal sequence of acquiring the adult-like swimming pattern and postural development in trained pups showed differences persisting until almost the second postnatal week. A very short motor training performed just after birth is thus able to induce functional adaptation in the developing neuromuscular system that could persist several days. This highlights the vulnerability of the neuromuscular apparatus during development and the need to evaluate carefully the impact of any given sensorimotor procedure when considering its application to improve motor development or in rehabilitation strategies.
在本研究中，我们旨在确定在新生小鼠脊髓运动和后肢肌肉发育的高度可塑性时期增加运动活动的影响。对1日龄和2日龄（P1、P2）的幼崽进行了游泳训练方案，每天进行两次，共两天。接受训练的P3幼崽表现出四肢游泳模式的更快习得，同时伴有外侧运动柱中基因表达失调、运动神经元（MNs）固有膜特性和突触可塑性的改变，以及脊髓运动区域轴突髓鞘形成增加。还观察到了网络水平的变化，因为训练改变了MNs中的突触事件以及脊髓去甲肾上腺素和5-羟色胺的含量。在肌肉水平上，在接受训练的动物中观察到后肢肌肉神经肌肉接头形态和肌球蛋白亚型表达的轻微变化。此外，接受训练的幼崽获得类似成年游泳模式和姿势发育的时间顺序显示出差异，这种差异一直持续到出生后第二周左右。因此，出生后立即进行的非常短暂的运动训练能够在发育中的神经肌肉系统中诱导功能适应，这种适应可能会持续数天。这突出了发育过程中神经肌肉装置的脆弱性，以及在考虑将任何给定的感觉运动程序应用于改善运动发育或康复策略时，仔细评估其影响的必要性。
