Morphological Remodeling of the Spinal Cord After Experimental Neurotmesis with Early Ipidacrine Administration: An Electron Microscopy Study

Background: Peripheral nerve injuries represent a significant medical and social concern both in peacetime and during armed conflict. These injuries require prolonged inpatient care and frequently result in long-term disability. In response to peripheral nerve damage, retrograde reactive changes occur in the parent neurons and associated spinal cord cells. Understanding these processes may allow for more accurate predictions of clinical outcomes and recovery timelines. Elucidating the response of the lumbar spinal cord segment to peripheral nerve injury and subsequent treatment may enhance therapeutic efficacy. AIM: To examine the regularities of reactive changes in the spinal cord segment following neurotmesis in order to improve the strategy and tactics of treating patients with this pathology. MATERIALS AND METHODS: Experimental neurotmesis of the sciatic nerve was surgically induced in six male Wistar rats. Three animals received ipidacrine for seven days, whereas the remaining three served as untreated controls. RESULTS: This electron microscopy study examined changes in the lumbar segment of the spinal cord seven days after neurotmesis, with and without ipidacrine treatment. Retrograde processes following sciatic nerve injury affected not only the parent neurons of the damaged fibers but also nerve fibers, glial cells (including oligodendrocytes), and the microcirculatory bed. Qualitative and quantitative differences in spinal cord morphology were observed between the experimental and control groups, and morphological predictors of successful recovery were identified. CONCLUSION: The results of this study demonstrated that a 7-day course of ipidacrine administration following sciatic nerve neurotmesis exerted a beneficial effect on adaptive neuroplastic processes in the lumbar segment of the spinal cord.