engleski

Regional and temporal pattern of neurodegeneration and synaptic reorganization after traumatic brain injury in the rat

Introduction: Traumatic brain injury (TBI) is one of the leading causes of death and disability worldwide associated with long-term cognitive and motor dysfunctions. TBI-induced primary injury is followed by complex secondary cascade of pathophysiological processes, such as excitotoxicity, oxidative stress, inflammation, etc. which contribute to tissue and cell damage. Processes of neuronal reorganization, plasticity and repair following TBI, which could have important role in post- injury recovery of the brain functions, are still poorly understood. The aim of this study was to determine the extent of neuronal damage and possible appearance of synaptic reorganization in the parietal cortex, dentate gyrus and thalamus after experimentally induced TBI. Material and methods: Adult male Wistar rats were connected to the lateral fluid percussion device via plastic Luer Lock fitting attached to the scull over the left parietal cortex and TBI of moderate severity was induced. Sham-operated animals were used as the control group. Rats were sacrificed 1, 3 and 7 days after the TBI induction or sham procedure and their brains were prepared for histological analyses. Fluoro-Jade B staining was used to identify the extent of neurodegeneration. Immunofluorescent labeling of synaptophysin (SYP) and the growth associated protein 43 (GAP-43) for the determination of neuroplastic responses was done. Results: Increased Fluoro- Jade B staining was apparent in all brain regions analyzed with delay in the structures distant from the impact site. Regional and temporal changes in the intensities of SYP and GAP-43 staining were also detected. Conclusion: This preliminary study suggests neurodegeneration and synaptic reorganization in the brain regions investigated at different time points following TBI in the rat.

traumatic brain injury; neurodegeneration; synaptic reorganisation

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