Ishihara A, Tsuzimoto H, Suzuki H, Kasuga N
Laboratory of Neurochemistry, Faculty of Integrated Human Studies, Kyoto University, Japan.
Brain Res Dev Brain Res. 1994 Nov 18;83(1):28-34. doi: 10.1016/0165-3806(94)90176-7.
The cell body size and succinate dehydrogenase (SDH) activity of spinal motoneurons innervating the superficial and deep regions of the tibialis anterior muscle were studied in rats ranging in postnatal age from 3 to 11 weeks, by retrograde neuronal labeling using fluorescent neuronal tracers. The motoneurons innervating the tibialis anterior muscle were located primarily at the L4 spinal cord segment and those innervating the superficial and deep regions of the muscle were distributed throughout the entire extent of the motoneuron pool. The distribution of the motoneurons during postnatal development was similar to that observed in the adult animal. The mean cell body size of the motoneurons innervating the superficial region of the muscle in rats from 5 to 11 weeks of age was greater than that innervating the deep region at corresponding ages. The mean SDH activity of the motoneurons innervating the deep region of the muscle increased during postnatal development, while there were no changes in the mean SDH activity of those innervating the superficial region during this period. At 11 weeks of age, the motoneurons innervating the deep region of the muscle had a higher mean SDH activity than those innervating the superficial region. An inverse relationship between cell body size and SDH activity of motoneurons innervating both the superficial and deep regions of the muscle was observed, independent of age. These results indicate that motoneurons innervating the superficial and deep regions of the rat tibialis anterior muscle have different developmental patterns with regard to cell body size and SDH activity.
通过使用荧光神经元示踪剂进行逆行神经元标记，研究了出生后3至11周龄大鼠中支配胫骨前肌浅部和深部区域的脊髓运动神经元的细胞体大小和琥珀酸脱氢酶（SDH）活性。支配胫骨前肌的运动神经元主要位于L4脊髓节段，而支配该肌肉浅部和深部区域的运动神经元分布在整个运动神经元池范围内。出生后发育过程中运动神经元的分布与成年动物中观察到的相似。5至11周龄大鼠中支配肌肉浅部区域的运动神经元的平均细胞体大小大于相应年龄时支配深部区域的运动神经元。支配肌肉深部区域的运动神经元的平均SDH活性在出生后发育过程中增加，而在此期间支配浅部区域的运动神经元的平均SDH活性没有变化。在11周龄时，支配肌肉深部区域的运动神经元的平均SDH活性高于支配浅部区域的运动神经元。观察到支配肌肉浅部和深部区域的运动神经元的细胞体大小与SDH活性之间存在反比关系，与年龄无关。这些结果表明，支配大鼠胫骨前肌浅部和深部区域的运动神经元在细胞体大小和SDH活性方面具有不同的发育模式。
