engleski

Repetitive mild traumatic brain injury: effects on Barnes maze performance and some parameteres of synaptic plasticity

Repetitive mild brain injury (rTBI) is a health problem frequent in athletes and soldiers. Clinical studies suggest short and long-term alterations in cognition, emotional and physical functioning following rTBI. The purpose of our research was to investigate the effects of rTBI on spatial learning/memory and activity dependent synaptic plasticity in mice. The animals were subjected to rTBI using modified weight drop method by Marmarou. rTBIs were performed twice daily, at intervals of 6 h, for 5 consecutive days. Sham treated, control animals were anesthetized without receiving the head impact. One day after the final injury/sham procedure they started training on Barnes maze apparatus. Mice were trained for four days and the probe trials were performed on the days 5 and 12. The time taken by the individual mouse to reach the target and/or neighbouring hole as well as the number of pokes (errors) in each hole were measured. Second group of mice did not undergo any behavior testing and were sacrificed at the 14th day after the last impact/sham procedure and their frontal cortices were prepared for Western blot analyses of postsynaptic density 95 (PSD95) and synaptophysin (Syp) proteins. No significant difference was detected in Barnes Maze performance between the experimental groups. Syp protein expression was not altered, while the PSD95 expression was significantly higher in the injured animals. This preliminary study suggests that rTBI does not affect spatial learning/memory but induces synaptic reorganization in the mouse frontal cortex in our experimental conditions.

repetitive traumatic brain injury ; Barnes maze ; synaptic plasticity ; mouse

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