Mattsson P, Meijer B, Svensson M
Department of Clinical Neuroscience, Section for Neurosurgery, Karolinska Hospital, Stockholm, Sweden.
Brain Res Bull. 1999 Jul 15;49(5):333-41. doi: 10.1016/s0361-9230(98)00178-6.
The aim of the present study is to examine the neuronal degeneration and the glial response following intracranial transection of the facial nerve close to the brainstem and furthermore to compare the results with a distal nerve injury. The facial nerve was cut either intracranially in the posterior cranial fossa or further distally, where it passes the parotid gland, in adult rats. Intracranial axotomy caused a massive loss of neuronal profiles. Only 26.8+/-11.3% of facial motor neuronal profiles were found ipsilateral to the nerve injury when compared to the contralateral side, following intracranial axotomy. This was statistically significant in comparison to the distal injury (72.4+/-9.5%), 4 weeks post-lesion. Reactive microglial cells expressed ED1 immunoreactivity following the intracranial axotomy but not following the distal nerve injury. In conclusion, there was a large discrepancy in neuronal degeneration as well as presence of phagocytic (ED1 positive) microglia between the two lesions. The intracranial lesion model used in the present study generates a massive neuronal cell death and should therefore be a useful tool for studies on proximal cranial nerve injuries and in particular mechanisms causing cell death, which may occur following, for example, head trauma.
本研究的目的是检查面神经在靠近脑干处进行颅内横断后神经元的变性情况以及胶质细胞的反应，此外还将结果与远端神经损伤进行比较。在成年大鼠中，面神经要么在颅后窝进行颅内切断，要么在其穿过腮腺的更远处进行切断。颅内轴突切断术导致神经元轮廓大量丧失。与对侧相比，颅内轴突切断术后，仅26.8±11.3%的面神经运动神经元轮廓在神经损伤同侧被发现。与损伤后4周的远端损伤（72.4±9.5%）相比，这具有统计学意义。颅内轴突切断术后，反应性小胶质细胞表达ED1免疫反应性，但远端神经损伤后则不表达。总之，两种损伤在神经元变性以及吞噬性（ED1阳性）小胶质细胞的存在方面存在很大差异。本研究中使用的颅内损伤模型会导致大量神经元细胞死亡，因此应该是研究近端颅神经损伤尤其是导致细胞死亡机制的有用工具，例如头部创伤后可能会发生这种情况。
