Identifying novel trunk reflexes and their differences after neonatal versus adult spinal cord injury

项目总结/摘要 脊髓损伤（SCI）中一个非常引人注目的观察结果是， 在猫、大鼠和小鼠的胸部水平，一部分受伤的个体发展出有用的四足动物的变异。 成年动物的体重支持运动，尽管成年动物完全脊髓横断后， 有用的恢复。在大鼠中，使用 后肢占20%了解新生儿脊髓完整后如何发展这种功能水平 损伤和维持成人可能是临床应用新疗法的重要标志。 我们和其他人发表的数据表明，躯干控制是至关重要的有用的四足重量- 支持新生损伤大鼠的运动。我们小组的新数据表明， 单突触对侧反射通路在大鼠躯干。这些反射将肌肉耦合到中线上 反应迅速其他已发表的数据表明，早期新生儿躯干运动神经元结构的改变 SCI可能会改变这些新发现的途径，这将影响躯干控制。这推测 差异可能是支持四足功能恢复异常良好的机制， 新生儿脊髓损伤我们在这个项目中的目标是测试在成年动物中看到的躯干反射模式是否 脊髓损伤后改变，重点是新的对侧单突触通路。我们假设 新生儿SCI后，新的对侧单突触通路丢失。我们用两个特定目标来测试这个， 第一种是用解剖描记法检验假设，第二种是用电生理反射检验假设 试验.该项目的意义在于，获得的数据将有助于更好地了解元素 脊髓损伤后躯干运动功能的恢复。数据将决定未来的方向 在啮齿动物模型中对新生儿和成人SCI的研究。中继控制和恢复中继控制是一种有效的 这是成年、青少年和新生儿SCI后运动功能恢复的关键方面。 根据结果，项目数据可能会导致设计新的治疗方法和啮齿动物试验， 转化为临床的可能性。

Project Summary / Abstract A highly compelling observation in spinal cord injury (SCI) is that in neonatal complete spinal transection at thoracic levels in cats, rats and mice, a fraction of the injured individuals develop variations of useful quadrupedal weight-supported locomotion as adults, although after complete spinal transection in adult animals there is no useful recovery. In rats the fraction of individuals that show integrated quadrupedal weight support, using the hindlimbs is about 20%. Understanding how this level of function is developed after neonatal spinal complete injury and maintained in adults may be an important signpost to new therapies applicable in clinic. We and others have published data indicating that trunk control is crucial to the useful quadrupedal weight- supported locomotion of neonatal injured rats. New data in our group suggested some previously undescribed monosynaptic contralateral reflex pathways in the rat trunk. These reflexes couple muscles across the midline with rapid reflexes. Other published data shows that alteration in trunk motoneuron structure in early neonate SCI which might alter these newly discovered pathways, which would impact trunk control. This speculated difference might be among mechanisms that support the unusually good recovery of quadrupedal function after neonatal SCI. Our goals in the proposed project are to test if the trunk reflex patterns seen in adult animals are altered after spinal cord injury, focusing on the novel contralateral monosynaptic pathways. We hypothesize that after neonatal SCI the novel contralateral monosynaptic pathways are lost. We test this with two Specific Aims, the first examining the hypothesis using anatomical tracing, and the second using electrophysiological reflex testing. The significance of the project is that the data to be obtained will lead to better understanding of elements of trunk motor function, and recovery of trunk motor function after SCI. The data will determine future directions of research in neonatal and adult SCI in rodent models. Trunk control and recovery of effective trunk control is a crucial aspect of the restoration and recovery of motor function after both adult, juvenile and neonatal SCI. Depending on the results, the project data may lead to the design of new therapies and tests in rodents, with potential for translation to clinic.