Vizzard M A
College of Medicine, University of Vermont, Department of Neurology 0540, USA.
Dev Neurosci. 1997;19(3):232-46. doi: 10.1159/000111212.
Changes in the distribution of neuronal nitric oxide synthase immunoreactivity (NOS-IR) after chronic (5-6 weeks) spinal cord injury (SCI) were examined in bladder afferent and spinal neurons in the region of the sacral parasympathetic nucleus (SPN) in the L6-S1 spinal segments. Bladder afferent neurons in the L1, L2, L6 and S1 dorsal root ganglia (DRG) were identified by retrograde axonal transport following injection of fluorogold (FG) into the urinary bladder. A differential distribution of NOS-IR was detected in DRG cells at different segmental levels of spinal cord intact animals with significantly greater numbers of NOS-IR cells present in thoracic (T8, T12; 30-40 NOS-IR cell profiles/section) and rostral lumbar (L1) DRGs (18 NOS-IR cell profiles/ section) compared to caudal lumbosacral (L5-S1) DRGs (0.2-0.4 NOS-IR cell profiles/section). A significant increase in the number of NOS-IR cells was detected in the L6-S1 DRG (p < or = 0.001; 12-20 NOS-IR cell profiles/section) and in the L1-L2 DRG (15-40 NOS-IR cell profiles/section) but not in the L5 DRG following SCI. In these ganglia, an average of 41.2 +/- 7.8% (L6) and 36.3 +/- 0.9% (S1) of FG-labeled bladder afferent neurons were NOS-IR. In contrast, in spinal cord intact animals, no FG-labeled bladder afferent neurons were NOS-IR. Following SCI, NOS-IR fibers were detected along the lateral edge of the dorsal horn extending from Lissauer's tract to the region of the SPN (lateral collateral pathway of Lissauer) of the L6 and S1 spinal segments. These NOS-IR fibers were not detected in adjacent spinal segments (L5, S2). SCI also significantly (p < or = 0.001) increased the number of spinal neurons in the region of the SPN (presumptive preganglionic neurons) in the L6-S1 spinal segments exhibiting NOS-IR. These results indicate that NOS-IR in bladder afferent and spinal neurons is plastic and can be up-regulated by chronic SCI. Changes in the neurochemical properties of these neurons after SCI may be mediated by pathological changes in the target organ (i.e., urinary bladder) and/or spinal cord.
在L6 - S1脊髓节段的骶副交感核（SPN）区域，对慢性（5 - 6周）脊髓损伤（SCI）后膀胱传入神经和脊髓神经元中神经元型一氧化氮合酶免疫反应性（NOS - IR）的分布变化进行了研究。通过将荧光金（FG）注入膀胱后逆行轴突运输，鉴定L1、L2、L6和S1背根神经节（DRG）中的膀胱传入神经元。在脊髓完整动物的不同节段水平的DRG细胞中检测到NOS - IR的差异分布，与腰骶尾部（L5 - S1）DRG（0.2 - 0.4个NOS - IR细胞轮廓/切片）相比，胸段（T8、T12；30 - 40个NOS - IR细胞轮廓/切片）和腰段头端（L1）DRG（18个NOS - IR细胞轮廓/切片）中存在明显更多的NOS - IR细胞。在SCI后，L6 - S1 DRG（p≤0.001；12 - 20个NOS - IR细胞轮廓/切片）和L1 - L2 DRG（15 - 40个NOS - IR细胞轮廓/切片）中检测到NOS - IR细胞数量显著增加，但L5 DRG中未增加。在这些神经节中，平均41.2±7.8%（L6）和36.3±0.9%（S1）的FG标记膀胱传入神经元为NOS - IR。相比之下，在脊髓完整的动物中，没有FG标记的膀胱传入神经元是NOS - IR。SCI后，在L6和S1脊髓节段，沿着背角外侧边缘从Lissauer束延伸至SPN区域（Lissauer外侧旁通路）检测到NOS - IR纤维。在相邻脊髓节段（L5、S2）未检测到这些NOS - IR纤维。SCI还显著（p≤0.001）增加了L
