Sexual dysfunction, following spinal cord injury (SCI), is highly dependent on the extent of injury. SCI disrupts the supraspinal innervation of the reproductive organs; resulting in structural and functional deficits. Relating the extent of SCI to these changes could eventually improve diagnoses and treatment planning of sexual dysfunction following SCI. In the present study, following chronic SCI of different severities (1/3 dorsal SCI (1/3 SCI), 2/3 dorsal SCI (2/3 SCI), and complete transection (Tx)) at T8 spinal level, histological changes of seminiferous tubules parameters in testis were examined. The diameter of seminiferous tubules (DST) and epithelial height of seminiferous tubules (HST) were significantly decreased in all SCI groups compared to control and sham. In addition, DST in 2/3 SCI and Tx groups and HST in Tx group were significantly decreased in comparison with 1/3 SCI animals. Nonetheless, the diameter of seminiferous tubules' lumen decreased significantly in 2/3 SCI and Tx compared to control, sham, and 1/3 SCI groups. Concerning cellular component, the number of spermatocytes and spermatids layers significantly decreased in both 1/3 and 2/3 SCI in comparison to normal. However, Tx had the most prominent deteriorating effect on these layers; indicating impairment in the process of spermatogenesis. These results show that the spinal tracts are part of the neural circuitries innervating the testis and responsible for their structural support. These tracts are mainly distributed between the lateral and ventral funiculi at T8 spinal level. Consequently, sparing ventral funiculi in the SCI prevents the severe decline in spermatogenesis.

中文翻译：

---

在慢性脊髓损伤中切断腹索对大鼠精子发生的影响最大

脊髓损伤 (SCI) 后的性功能障碍高度依赖于损伤的程度。SCI 破坏了生殖器官的脊髓上神经支配；导致结构和功能缺陷。将 SCI 的程度与这些变化联系起来，最终可以改善 SCI 后性功能障碍的诊断和治疗计划。在本研究中，在 T8 脊髓水平发生不同严重程度的慢性 SCI（1/3 背侧 SCI（1/3 SCI）、2/3 背侧 SCI（2/3 SCI）和完全横断（Tx））后，组织学变化检查了睾丸中的生精小管参数。与对照组和假手术组相比，所有 SCI 组的曲细精管直径 (DST) 和曲细精管上皮高度 (HST) 均显着降低。此外，与 1/3 SCI 动物相比，2/3 SCI 和 Tx 组的 DST 和 Tx 组的 HST 显着降低。尽管如此，与对照组、假手术组和 1/3 SCI 组相比，2/3 SCI 和 Tx 组的生精小管管腔直径显着减小。关于细胞成分，与正常相比，1/3 和 2/3 SCI 中精母细胞和精子细胞层的数量显着减少。然而，Tx 对这些层的恶化影响最为显着；表明精子发生过程中的障碍。这些结果表明，脊髓束是支配睾丸的神经回路的一部分，并负责其结构支持。这些束主要分布在 T8 脊髓水平的侧索和腹索之间。最后，