正常成年大鼠脊髓灰质nNOS阳性神经元的形态学探察

Morphological observation on spinal nNOS positive neurons in normal adult rat

目的探察大鼠脊髓灰质n NOS阳性神经元的形态和分布特征。方法免疫组织化学PAP方法被利用去探察大鼠颈、胸和腰骶脊髓灰质不同区域n NOS阳性神经元的大小、数量及分布。结果光镜观察显示,n NOS阳性神经元明显集中分布于脊髓中央管外周的灰质(中间带),但在腰骶脊髓灰质背侧角Ⅱ、Ⅲ层也呈现密集分布,而在颈脊髓和胸脊髓灰质Ⅳ和Ⅴ层同时可见散在分布。比较结果显示,腰骶脊髓灰质中间带的n NOS阳性神经元显著多于颈脊髓和胸脊髓(P<0.05),而且n NOS阳性神经元在颈、胸和腰骶脊髓灰质的中间带均多于它们各自的背侧角(P<0.05、P<0.05、P<0.05)。进一步对n NOS阳性神经元大小的比较结果显示,腰骶脊髓灰质中间带的n NOS阳性神经元明显大于颈脊髓和胸脊髓(P<0.05),但阳性胞体的大小在颈、胸、腰骶脊髓灰质背侧角相互之间无统计学差异(P>0.05)。结论大鼠脊髓灰质n NOS阳性神经元形态和分布特征可能牵涉到脊髓不同部位和区域的机能。

Objective To explore the morphological characteristics and distribution pattern of nNOS positive neurons in rat spinal cord. Methods The expression of nNOS positive neurons were detected by PAP immunohistochemistry, investigating the morphology, number and distribution in different regions of cervical, thoracic, lumbosacral spinal cord. Results nNOS positive neurons were mainly distributed in central canal （intermediate zone）, also intensively distributed in the lumbosacral dorsal horn, while sparsely in lamina IV, V of cervical, thoracic spinal cord. Comparative result showed, neurons in the intermediate zone of lumbosacral spinal cord were more than in cervical and thoracic spinal cord （P〈0.05）, in addition, neurons in the intermediate zone were more than in the dorsal horn of different segments （P〈0.05, P〈0.05, P〈0.05）. Further comparison showed, neurons in the intermediate zone of lumbosacral spinal cord were larger than incervical and thoracic spinal cord （P〈0.05）, but there was no statistical difference among the dorsal horn of cervical, thoracic, lumbosacral spinal cord （P〉0.05）. Conclusion The morphological characteristics and distribution pattern of nNOS positive neurons in rat spinal cord may play an important role in the function of different regions and segments.