Brozanski B S, Guthrie R D, Volk E A, Cameron W E
Department of Pediatrics, Magee-Womens Hospital, Pittsburgh, Pennsylvania 15213.
Pediatr Pulmonol. 1989;7(3):133-9. doi: 10.1002/ppul.1950070304.
The postnatal growth of kitten genioglossal motoneurons were examined in six different age groups (newborn, 2, 4, 8, and 12 weeks and adult) using the technique of retrograde transport of horseradish peroxidase (HRP). The cell bodies of 100-150 motoneurons in each age group were analyzed in a transverse plane of section using standard techniques. Somatic genioglossal motoneuron growth occurred primarily along the major axis, which increased from 25.2 microns to 41.3 microns between birth and 8 weeks of postnatal age, after which time there was no further increase in either major or minor dimension of the cell body. The form factor decreased from 0.94 to 0.80 from birth to adulthood indicating an increased eccentricity of the cell body. The number of primary dendrites visible with this technique remained constant throughout the postnatal period. Calculated somal surface area increased in a linear fashion from birth through 8 weeks of postnatal life. There was no further increase in surface area beyond this age. The rate of increase in somal surface area with age was significantly different from both the rate of increase of animal weight and animal surface area with age. The correlations between the demonstrated immature genioglossal morphology and its cellular electrophysiology or integrated respiratory function remain unknown. The recent demonstration of decreased activation of the genioglossus muscle following airway occlusion in premature infants with apnea suggests that the relationships between developing genioglossal motoneuron structure and function warrant further investigation.
采用辣根过氧化物酶（HRP）逆行运输技术，对六个不同年龄组（新生、2周、4周、8周、12周和成年）的小猫颏舌肌运动神经元的出生后生长情况进行了研究。使用标准技术，在每个年龄组的100 - 150个运动神经元的细胞体的横断面进行分析。躯体颏舌肌运动神经元的生长主要沿主轴进行，在出生至出生后8周期间，主轴长度从25.2微米增加到41.3微米，此后细胞体的长轴和短轴尺寸均未进一步增加。从出生到成年，形状因子从0.94降至0.80，表明细胞体的偏心率增加。用该技术可见的初级树突数量在整个出生后时期保持恒定。计算得出的体细胞表面积在出生至出生后8周呈线性增加。超过这个年龄后表面积不再增加。体细胞表面积随年龄的增加速率与动物体重和动物表面积随年龄的增加速率均有显著差异。所显示的未成熟颏舌肌形态与其细胞电生理学或整合呼吸功能之间的相关性尚不清楚。最近的研究表明，呼吸暂停的早产儿气道阻塞后颏舌肌的激活减少，这表明发育中的颏舌肌运动神经元结构与功能之间的关系值得进一步研究。
