Functional Motor Recovery from Motoneuron Axotomy Is Compromised in Mice with Defective Corticospinal Projections
| Autor: | Libing Zhou, Jia Feng, Wutian Wu, Meizhi Wang, Qi Han, Kwok-Fai So, Yuetong Ding, Yibo Qu |
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| Rok vydání: | 2014 |
| Předmět: |
Male
Critical Care and Emergency Medicine medicine.medical_treatment Neuromuscular Junction Pyramidal Tracts lcsh:Medicine Mice Transgenic Nerve Fibers Myelinated Nervous System Avulsion Behavioral Neuroscience GAP-43 Protein Atrophy Developmental Neuroscience Neurobiology of Disease and Regeneration Medicine and Health Sciences medicine Animals Brachial Plexus Remyelination Muscle Skeletal Spinal Cord Injury lcsh:Science Trauma Medicine Motor Neurons Multidisciplinary biology lcsh:R Biology and Life Sciences Axotomy Recovery of Function Anatomy medicine.disease Spinal cord Nerve Regeneration Motor System Myelin basic protein medicine.anatomical_structure Neurology Brachial plexus injury Corticospinal tract biology.protein Female lcsh:Q Research Article Developmental Biology Neuroscience |
| Zdroj: | PLoS ONE, Vol 9, Iss 7, p e101918 (2014) PLoS ONE |
| ISSN: | 1932-6203 |
| DOI: | 10.1371/journal.pone.0101918 |
| Popis: | Brachial plexus injury (BPI) and experimental spinal root avulsion result in loss of motor function in the affected segments. After root avulsion, significant motoneuron function is restored by re-implantation of the avulsed root. How much this functional recovery depends on corticospinal inputs is not known. Here, we studied that question using Celsr3|Emx1 mice, in which the corticospinal tract (CST) is genetically absent. In adult mice, we tore off right C5–C7 motor and sensory roots and re-implanted the right C6 roots. Behavioral studies showed impaired recovery of elbow flexion in Celsr3|Emx1 mice compared to controls. Five months after surgery, a reduced number of small axons, and higher G-ratio of inner to outer diameter of myelin sheaths were observed in mutant versus control mice. At early stages post-surgery, mutant mice displayed lower expression of GAP-43 in spinal cord and of myelin basic protein (MBP) in peripheral nerves than control animals. After five months, mutant animals had atrophy of the right biceps brachii, with less newly formed neuromuscular junctions (NMJs) and reduced peak-to-peak amplitudes in electromyogram (EMG), than controls. However, quite unexpectedly, a higher motoneuron survival rate was found in mutant than in control mice. Thus, following root avulsion/re-implantation, the absence of the CST is probably an important reason to hamper axonal regeneration and remyelination, as well as target re-innervation and formation of new NMJ, resulting in lower functional recovery, while fostering motoneuron survival. These results indicate that manipulation of corticospinal transmission may help improve functional recovery following BPI. |
| Databáze: | OpenAIRE |
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