scholarly journals Examining the Progressive Behavior and Neuropathological Outcomes Associated with Chronic Repetitive Mild Traumatic Brain Injury in Rats

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Eric Eyolfson ◽  
Glenn R Yamakawa ◽  
Yannick Griep ◽  
Reid Collins ◽  
Thomas Carr ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Motor Behavior ◽  
Functional Change ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Behavioral Impairment ◽  
Motor Disturbance ◽  
Ventricle Size

Abstract While the physical and behavioral symptomologies associated with a single mild traumatic brain injury (mTBI) are typically transient, repetitive mTBIs (RmTBI) have been associated with persisting neurological deficits. Therefore, this study examined the progressive changes in behavior and the neuropathological outcomes associated with chronic RmTBI through adolescence and adulthood in male and female Sprague Dawley rats. Rats experienced 2 mTBIs/week for 15 weeks and were periodically tested for changes in motor behavior, cognitive function, emotional disturbances, and aggression. Brain tissue was examined for neuropathological changes in ventricle size and presentation of Iba1 and GFAP. We did not see progressively worse behavioral impairments with the accumulation of injuries or time, but did find evidence for neurological and functional change (motor disturbance, reduced exploration, reduced aggression, alteration in depressive-like behavior, deficits in short-term working memory). Neuropathological assessment of RmTBI animals identified an increase in ventricle size, prolonged changes in GFAP, and sex differences in Iba1, in the corpus callosum, thalamus, and medial prefrontal cortex. Telomere length reduced exponentially as the injury load increased. Overall, chronic RmTBI did not result in accumulating behavioral impairment, and there is a need to further investigate progressive behavioral changes associated with repeated injuries in adolescence and young adulthood.

scholarly journals Repeated Mild Traumatic Brain Injury Results in Long-Term White-Matter Disruption

2014 ◽  
Vol 34 (4) ◽  
pp. 715-723 ◽  
Author(s):  
Virginia Donovan ◽  
Claudia Kim ◽  
Ariana K Anugerah ◽  
Jacqueline S Coats ◽  
Udochuwku Oyoyo ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
White Matter ◽  
Mild Traumatic Brain Injury ◽  
Diffusion Tensor ◽  
Ex Vivo ◽  
Health Concern ◽  
Sprague Dawley ◽  
G Ratio

Mild traumatic brain injury (mTBI) is an increasing public health concern as repetitive injuries can exacerbate existing neuropathology and result in increased neurologic deficits. In contrast to other models of repeated mTBI (rmTBI), our study focused on long-term white-matter abnormalities after bilateral mTBIs induced 7 days apart. A controlled cortical impact (CCI) was used to induce an initial mTBI to the right cortex of Single and rmTBI Sprague Dawley rats, followed by a second injury to the left cortex of rmTBI animals. Shams received only a craniectomy. Ex vivo diffusion tensor imaging (DTI), transmission electron microscopy (TEM), and histology were performed on the anterior corpus callosum at 60 days after injury. The rmTBI animals showed a significant bilateral increase in radial diffusivity (myelin), while only modest changes in axial diffusivity (axonal) were seen between the groups. Further, the rmTBI group showed an increased g-ratio and axon caliber in addition to myelin sheath abnormalities using TEM. Our DTI results indicate ongoing myelin changes, while the TEM data show continuing axonal changes at 60 days after rmTBI. These data suggest that bilateral rmTBI induced 7 days apart leads to progressive alterations in white matter that are not observed after a single mTBI.

scholarly journals Fecal Microbiota Transplantation Is a Promising Method to Restore Gut Microbiota Dysbiosis and Relieve Neurological Deficits after Traumatic Brain Injury

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Donglin Du ◽  
Wei Tang ◽  
Chao Zhou ◽  
Xiaochuan Sun ◽  
Zhengqiang Wei ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Gut Microbiota ◽  
Fecal Microbiota Transplantation ◽  
Fecal Microbiota ◽  
Methionine Sulfoxide Reductase ◽  
Neurological Deficits ◽  
Sprague Dawley ◽  
Rat Serum ◽  
Gut Microbiota Dysbiosis

Background. Traumatic brain injury (TBI) can induce persistent fluctuation in the gut microbiota makeup and abundance. The present study is aimed at determining whether fecal microbiota transplantation (FMT) can rescue microbiota changes and ameliorate neurological deficits after TBI in rats. Methods. A controlled cortical impact (CCI) model was used to simulate TBI in male Sprague-Dawley rats, and FMT was performed for 7 consecutive days. 16S ribosomal RNA (rRNA) sequencing of fecal samples was performed to analyze the effects of FMT on gut microbiota. Modified neurological severity score and Morris water maze were used to evaluate neurobehavioral functions. Metabolomics was used to screen differential metabolites from the rat serum and ipsilateral brains. The oxidative stress indices were measured in the brain. Results. TBI induced significance changes in the gut microbiome, including the alpha- and beta-bacterial diversity, as well as the microbiome composition at 8 days after TBI. On the other hand, FMT could rescue these changes and relieve neurological deficits after TBI. Metabolomics results showed that the level of trimethylamine (TMA) in feces and the level of trimethylamine N-oxide (TMAO) in the ipsilateral brain and serum was increased after TBI, while FMT decreased TMA levels in the feces, and TMAO levels in the ipsilateral brain and serum. Antioxidant enzyme methionine sulfoxide reductase A (MsrA) in the ipsilateral hippocampus was decreased after TBI but increased after FMT. In addition, FMT elevated SOD and CAT activities and GSH/GSSG ratio and diminished ROS, GSSG, and MDA levels in the ipsilateral hippocampus after TBI. Conclusions. FMT can restore gut microbiota dysbiosis and relieve neurological deficits possibly through the TMA-TMAO-MsrA signaling pathway after TBI.

scholarly journals A simple rat model of mild traumatic brain injury: device to reproduce anatomical and neurological changes of mild traumatic brain injury

2016 ◽  
Author(s):  
Ho Jeong Kim ◽  
Soo Jeong Han
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Water Pressure ◽  
Brain Mri ◽  
Free Fall ◽  
Absolute Number ◽  
Grid Floor ◽  
Sprague Dawley ◽  
The Brain

Mild traumatic brain injury typically involves temporary impairment of neurological function. Previous studies used the water pressure or rotational injury for designing the device to make a rat mild traumatic brain injury model. The objective of this study was to make a simple model of mild traumatic brain injury in rat. The device consisted of a free-fall impactor that was targeted onto the rat skull. The weight (175g) was freely dropped 30cm to rat’s skull bregma. We installed a safety device made of acrylic panel. To confirm a mild traumatic brain injury in 36 Sprague–Dawley rats, we performed the brain magnetic resonance image(MRI) within 24 hours after injury. We evaluated behavior and chemical changes in rats before and after mild traumatic brain injury. The brain MRI did not show high or low signal intensity in 34 rats. The mobility on grid floor was decreased after mild traumatic brain injury. Absolute number of foot-fault and foot-fault ratio were decreased after mild traumatic brain. But the difference of ratio was lesser than absolute number of foot-fault. These results show that the device is capable of reproducing mild traumatic brain injury in rat. Our device can reduce the potential to cause brain hemorrhage and reflect the mechanism of real mild traumatic brain injury compared with existing methods and behaviors. This model can be useful in exploring physiology and management of mild traumatic brain injury.

scholarly journals Modeling traumatic brain injury combined with hemorrhagic shock in rats: Neurological assessment and PET imaging with 18F-fluorodeoxyglucaric acid

2021 ◽  
Author(s):  
Hibah O Awwad ◽  
Andria Hedrick ◽  
Alex Mdzinarishvili ◽  
Hailey Houson ◽  
Kelly Standifer ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Hemorrhagic Shock ◽  
Tissue Injury ◽  
Brain Lesion ◽  
Lesion Size ◽  
Neurological Deficits ◽  
Lesion Volume ◽  
Sprague Dawley ◽  
The Impact

Traumatic brain injury (TBI)is a major cause of death and disability worldwide. Hemorrhagic shock (HS) aggravates tissue injury and complicates TBI recovery. We studied the combined insult of mild TBI and HS and investigated the impact of varying loss of blood volume on neurologic deficit and brain lesion volume. A novel positron emission tomography (PET) technique was employed to monitor tissue injury. Male Sprague Dawley rats received mTBI by controlled cortical impact (CCI) followed by withdrawal of 0%, 30-40%, 45%, or 50% of blood (mTBI, mTBI+HS≤40%, mTBI+HS45%, and mTBI+HS50%, respectively). Neurological deficit (mNSS= 5.6, 7.6, and 12.3) and mortality (2/12, 2/6, and 7/12) were higher in mTBI+HS≤40%, mTBI+HS45%, and mTBI+HS50%, than in mTBI alone rats (no death; mNSS=3.3). Histologic lesion size increased 3.5-fold in mTBI+HS50% compared to mTBI alone and the infarct-avid PET agent 18F-fluorodeoxyglucaric acid (FGA) proportionately detected tissue necrosis in mTBI+HS50% rats. Based on these results, we conclude that HS aggravates mTBI-induced neurological deficits, tissue injury and mortality. PET using 18F-FGA as an imaging marker can detect the extent of injury in a non-invasive manner.

scholarly journals A simple rat model of mild traumatic brain injury: a device to reproduce anatomical and neurological changes of mild traumatic brain injury

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2818 ◽  
Author(s):  
Ho Jeong Kim ◽  
Soo Jeong Han
Keyword(s):  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Mild Traumatic Brain Injury ◽  
Water Pressure ◽  
Brain Mri ◽  
Free Fall ◽  
Absolute Number ◽  
Grid Floor ◽  
Sprague Dawley ◽  
The Brain

Mild traumatic brain injury typically involves temporary impairment of neurological function. Previous studies used water pressure or rotational injury for designing the device to make a rat a mild traumatic brain injury model. The objective of this study was to make a simple model of causing mild traumatic brain injury in rats. The device consisted of a free-fall impactor that was targeted onto the rat skull. The weight (175 g) was freely dropped 30 cm to rat’s skull bregma. We installed a safety device made of acrylic panel. To confirm a mild traumatic brain injury in 36 Sprague-Dawley rats, we performed magnetic resonance imaging (MRI) of the brain within 24 h after injury. We evaluated behavior and chemical changes in rats before and after mild traumatic brain injury. The brain MRI did not show high or low signal intensity in 34 rats. The mobility on grid floor was decreased after mild traumatic brain injury. The absolute number of foot-fault and foot-fault ratio were decreased after mild traumatic brain injury. However, the difference of the ratio was a less than absolute number of foot-fault. These results show that the device is capable of reproducing mild traumatic brain injury in rats. Our device can reduce the potential to cause brain hemorrhage and reflect the mechanism of real mild traumatic brain injury compared with existing methods and behaviors. This model can be useful in exploring physiology and management of mild traumatic brain injury.

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