Bregman B S, Goldberger M E
Brain Res. 1983 Aug;285(2):103-17. doi: 10.1016/0165-3806(83)90045-7.
This study was undertaken to determine the effect of spinal cord damage on motor development, and to determine whether there is greater survival of motor function in those motor patterns with a later onset of function than in those which are present at birth. The postnatal development of postural reflexes and locomotion was examined during the first 4 months of life in normal kittens and in those which had received a spinal cord lesion (at high cervical or low thoracic levels) at birth. The results suggest that there are some similarities in normal development, recovery of function after adult lesions and recovery and/or development of function after neonatal lesions. After neonatal lesions, just as after lesions in adults, reflex recovery appears to underlie recovery of locomotion. After spinal lesions, the pattern and sequence of motor development was identical to that seen in normal animals. Hindlimb motor development was normal for some time after the spinal lesion, but deficits appeared later. These observations suggest that postural reflexes and locomotion are not dependent upon ipsilateral descending input for their onset, but only for their maturation. Unexpectedly, tactile placing developed after neonatal spinal cord lesions. This represents sparing of function, for tactile placing is abolished and does not recover after the same lesion sustained in adulthood. Tactile placing is the last of the series of postural reflexes to develop. It depends on the last of the spinal pathways to develop, the corticospinal tract. Two aspects of this study support the hypothesis that later developing motor patterns will have a greater chance for survival and subsequent development than those which are present at birth. First, the immediate effects of spinal cord lesions on postural reflexes are more severe on those reflexes that are more mature at birth. Second, the spinal cord lesions produce more severe impairment of the more mature forelimb motor function than of the less mature hindlimb motor function. The hypothesis is not supported, however, when the long-term effect of spinal cord lesions on the maturation of motor behavior is considered. All postural reflexes and locomotion fail to mature fully, i.e. they retain characteristics of the immature responses.
本研究旨在确定脊髓损伤对运动发育的影响，并确定功能出现较晚的运动模式中的运动功能存活情况是否比出生时就存在的运动模式更好。在正常小猫以及出生时接受脊髓损伤（高颈段或低胸段水平）的小猫出生后的前4个月，对其姿势反射和运动的产后发育进行了检查。结果表明，正常发育、成年损伤后的功能恢复以及新生损伤后的功能恢复和/或发育存在一些相似之处。新生损伤后，与成年损伤后一样，反射恢复似乎是运动恢复的基础。脊髓损伤后，运动发育的模式和顺序与正常动物相同。脊髓损伤后的一段时间内后肢运动发育正常，但随后出现了缺陷。这些观察结果表明，姿势反射和运动的起始并不依赖于同侧下行输入，而仅依赖于其成熟过程。出乎意料的是，新生脊髓损伤后触觉放置出现了。这代表了功能的保留，因为触觉放置在成年后遭受相同损伤后会被消除且不会恢复。触觉放置是一系列姿势反射中最后发育的。它依赖于最后发育的脊髓通路，即皮质脊髓束。本研究的两个方面支持了这样的假设，即较晚发育的运动模式比出生时就存在的运动模式有更大的存活和后续发育机会。首先，脊髓损伤对姿势反射的即时影响在出生时更成熟的反射上更为严重。其次，脊髓损伤对更成熟的前肢运动功能的损害比对不太成熟的后肢运动功能的损害更严重。然而，当考虑脊髓损伤对运动行为成熟的长期影响时，该假设并不成立。所有姿势反射和运动都未能完全成熟，即它们保留了不成熟反应的特征。
