The Neurobehavioral Response in a Rat Model of Brain Injury Using the Weight Drop Method.

Objective: To evaluate the effects of high-impact loads in a weight drop (WD) model of traumatic brain injury (TBI) on sustained neurobehavioral dysfunction over a 14-day period.

Methods: The experimental treatment involved craniotomy of rats, exposing the brain to a load applied via the WD method. Loads of 10 g were dropped from heights of 5, 10, and 15 cm. Neurobehavioral assessments included the Barnes maze for cognitive and affective function evaluation and the beam walking test for motor function assessment. Statistical analyses were conducted using the Statistical Package for the Social Sciences (SPSS) version 22 and GraphPad Prism version 9 software. Statistical significance was set at p<0.05.

Results: In the Barnes maze test, an increase in WD height was directly proportional to the post-test mean score, indicating poorer cognitive performance, with WD 15 cm yielding the highest mean score (146.6±16.8), followed by WD 10 cm (114.7±22.7) and WD 5 cm (100.6±18.6). Conversely, in the beam walk test, an increase in WD height contributed to a decline in motor performance, with the lowest mean score observed at WD 15 cm (20.6±9.84), while WD 10 cm (52.5±9.79) and WD 5 cm (74.7±12.5) showed less impairment.

Conclusion: Load-height variations in WD TBI models significantly influence neurobehavioral outcomes, with the 15 cm height having the most pronounced effect, inducing impairments in motor, cognitive, and affective functions.