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Updated: Jun 27, 2025
A Novel and Translational Rat Model of Concussion Combining Force and Rotation with In Vivo Cerebral Microdialysis
Published on: July 12, 2019
Short-term behavioral and histological findings following a single concussive and repeated subconcussive brain injury
Anna Marie Clay1, Russell L Carr2, Janice L DuBien3
1Department of Agricultural and Biological Engineering, Mississippi State University, Mississippi, USA.
Primary Objective:
It is unclear of the correlation between a mild traumatic brain injury (mTBI) and repeated subconcussive (RSC) impacts with respect to injury biomechanics. Thus, the present study was designed to determine the behavioral and histological differences between a single mTBI impact and RSC impacts with subdivided cumulative kinetic energies of the single mTBI impact.
Research Design:
Adult male Sprague-Dawley rats were randomly assigned to a single mTBI impact, RSC impact, sham, or repeated sham groups.
Methods And Procedures:
Following a weight drop injury, anxiety-like behavior and general locomotive activity and were assessed using the open field test, while motor coordination was evaluated using a rotarod unit. Neuronal loss, astrogliosis, and microgliosis were assessed using NeuN, GFAP and Iba-1 immunohistochemistry. All assessments were undertaken at 3- and 7-days post impact.
Main Outcomes And Results:
No behavioral disturbances were observed in injury groups, however, both injury groups did lead to microgliosis following 3-days post-impact.
Conclusions:
No pathophysiological differences were observed between a single mTBI impact and RSC impacts of the same energy input. Even though a cumulative injury threshold for RSC impacts was not determined, a threshold still may exist where no pathodynamic shift occurs.
Insights
Mild traumatic brain injury (mTBI) and repeated subconcussive (RSC) impacts show no behavioral differences. However, both injury types cause microgliosis, suggesting a potential cumulative injury threshold for RSC impacts.
Area of Science:
- Neuroscience
- Biomechanics
- Toxicology
Background:
- The correlation between mild traumatic brain injury (mTBI) and repeated subconcussive (RSC) impacts on injury biomechanics remains unclear.
- Understanding these differences is crucial for assessing the long-term effects of head trauma.
Purpose of the Study:
- To determine behavioral and histological differences between a single mTBI and RSC impacts.
- To investigate the effects of subdivided cumulative kinetic energies of RSC impacts compared to a single mTBI.
Main Methods:
- Adult male Sprague-Dawley rats were subjected to single mTBI, RSC impact, or sham procedures.
- Behavioral assessments (open field test, rotarod) and histological analyses (NeuN, GFAP, Iba-1 immunohistochemistry) were performed at 3 and 7 days post-impact.
Main Results:
- No significant behavioral disturbances were observed in any injury groups.
- Both single mTBI and RSC impacts resulted in microgliosis at 3 days post-impact.
Conclusions:
- No pathophysiological differences were found between single mTBI and RSC impacts with equivalent energy input.
- A cumulative injury threshold for RSC impacts may exist, below which no significant pathodynamic shift occurs.
