Changes in rat cerebral mitochondrial succinate dehydrogenase activity after brain trauma

A Systematic Review of Closed Head Injury Models of Mild Traumatic Brain Injury in Mice and Rats

Mild TBI (mTBI) is a significant health concern. Animal models of mTBI are essential for understanding mechanisms, and pathological outcomes, as well as to test therapeutic interventions. A variety of closed head models of mTBI that incorporate different aspects (i.e., biomechanics) of the mTBI have been reported. The aim of the current review was to compile a comprehensive list of the closed head mTBI rodent models, along with the common data elements, and outcomes, with the goal to summarize the current state of the field. Publications were identified from a search of PubMed and Web of Science and screened for eligibility following PRISMA guidelines. Articles were included that were closed head injuries in which the authors classified the injury as mild in rats or mice. Injury model and animal-specific common data elements, as well as behavioral and histological outcomes, were collected and compiled from a total of 402 articles. Our results outline the wide variety of methods used to model mTBI. We also discovered that female rodents and both young and aged animals are under-represented in experimental mTBI studies. Our findings will aid in providing context comparing the injury models and provide a starting point for the selection of the most appropriate model of mTBI to address a specific hypothesis. We believe this review will be a useful starting place for determining what has been done and what knowledge is missing in the field to reduce the burden of mTBI.

Effects of hydroxysafflor yellow A on the experimental traumatic brain injury in rats

This paper explores the effects of hydroxysafflor yellow A (HSYA) on traumatic brain injury (TBI). Rats were divided into four groups: control, TBI, TBI combined with HSYA, and TBI combined with nimodipine. Saline, HSYA, or nimodipine was i.v. injected at 30 min before and 6 h after the onset of TBI. The contusion volume of brain, mitochondrial ATPase activity, brain malondialdehyde (MDA) content, and the concentrations of tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in the blood plasma were investigated. The results showed that the inhibitory rate of HSYA at a dose of 4 mg/kg was 59.2% compared with the TBI group. After the insult by TBI for 48 h, the activity of Na(+), K(+)-ATPase, Ca(2+)-ATPase, and Mg(2+)-ATPase decreased to 31, 35, and 38% of control group. HSYA increased these ATPase activities by 162, 96, and 131% of TBI group. HSYA also increased superoxide dismutase activity and decreased MDA content in the right parietal lobe adjacent to contusion foci in TBI rats. HSYA enhanced the t-PA activity by 64.64%, decreased the PAI-1 activity by 71.88%, and decreased the MMP-9 expression to 49.11% in the hippocampus of the TBI group at 12 h. In conclusion, HSYA may exert a potential therapeutic strategy to improve the outcome following TBI injury.

Imaging cortical absorption, scattering, and hemodynamic response during ischemic stroke using spatially modulated near-infrared illumination

We describe a technique that uses spatially modulated near-infrared (NIR) illumination to detect and map changes in both optical properties (absorption and reduced scattering parameters) and tissue composition (oxy- and deoxyhemoglobin, total hemoglobin, and oxygen saturation) during acute ischemic injury in the rat barrel cortex. Cerebral ischemia is induced using an open vascular occlusion technique of the middle cerebral artery (MCA). Diffuse reflected NIR light (680 to 980 nm) from the left parietal somatosensory cortex is detected by a CCD camera before and after MCA occlusion. Monte Carlo simulations are used to analyze the spatial frequency dependence of the reflected light to predict spatiotemporal changes in the distribution of tissue absorption and scattering properties in the brain. Experimental results from seven rats show a 17+/-4.7% increase in tissue concentration of deoxyhemoglobin and a 45+/-3.1, 23+/-5.4, and 21+/-2.2% decrease in oxyhemoglobin, total hemoglobin concentration and cerebral tissue oxygen saturation levels, respectively, 45 min following induction of cerebral ischemia. An ischemic index (I(isch)=ctHHbctO(2)Hb) reveals an average of more then twofold contrast after MCAo. The wavelength-dependence of the reduced scattering (i.e., scatter power) decreased by 35+/-10.3% after MCA occlusion. Compared to conventional CCD-based intrinsic signal optical imaging (ISOI), the use of structured illumination and model-based analysis allows for generation of separate maps of light absorption and scattering properties as well as tissue hemoglobin concentration. This potentially provides a powerful approach for quantitative monitoring and imaging of neurophysiology and metabolism with high spatiotemporal resolution.

Prevention of traumatic headache, dizziness and fatigue with creatine administration. A pilot study

Aim

The complex pathobiology of traumatic brain injury (TBI) offers numerous targets for potential neuroprotective agents. We evaluate the clinical benefit after creatine (Cr) administration in children and adolescents

Methods

A prospective, randomized, comparative, open- labelled pilot study of the possible neuroprotective effect of Cr was carried out on 39 children and adolescents, aged between 1 and 18 years of age, with TBI. The Cr was administered for 6 months, at a dose of 0.4 g/kg in an oral suspension form every day. For categorical variables, we used the Chi-square test to identify differences between controls and cases. Statistical significance was defined as a p-value < 0.05 and not statistically significant if p-value > 0.1.

Results

The administration of Cr to children and adolescents with TBI improved results in several parameters, including duration of post traumatic amnesia (PTA), duration of intubation, intensive care unit stay. Significant improvement was recorded in the categories of headache (p < 0.001), dizziness (p = 0.005) and fatigue (p < 0.001), aspects in all patients. No side effects were seen due to Cr administration.

Conclusion

More specific examinations including brain spectroscopy for in vivo evaluation of Cr can be done, in order to draw conclusions for the optimal duration and manner of Cr supply, as well as its possible role for the prevention of TBI complications, in double blind studies.

Prevention of complications related to traumatic brain injury in children and adolescents with creatine administration: an open label randomized pilot study

BACKGROUND

There has been an enormous focus on the discovery and development of neuroprotective agents that might have clinical relevance after traumatic brain injury (TBI). Based on experimental facts, we studied administration of creatine to patients with TBI.

METHODS

A prospective, randomized, comparative, open-labeled pilot study of the possible neuroprotective effect of creatine was performed on 39 children and adolescents, aged between 1 to 18 years old, with TBI. The creatine was administered for 6 months, at a dose of 0.4 gr/kg in an oral suspension form every day. For categorical variables, we used the chi test to identify differences between controls and cases. Statistical significance was defined as a p value <0.05 and not statistically significant if p value >0.1.

RESULTS

The administration of creatine to children with TBI improved results in several parameters, including duration of post-traumatic amnesia (PTA), duration of intubation, intensive care unit (ICU) stay, disability, good recovery, self care, communication, locomotion, sociability, personality/behavior and neurophysical, and cognitive function. Significant improvement was recorded in the categories of Cognitive (p < 0.001), personality/behavior (p < 0.001), Self Care (p = 0.029), and communication (p = 0.018) aspects in all patients. No side effects were seen because of creatine administration.

CONCLUSION

Preliminary data suggest that the administration of creatine may be beneficial to patients with traumatic brain injury.

Catalase Activity and Thiobarbituric Acid Reactive Substances (TBARS) Production in a Rat Model of Diffuse Axonal Injury. Effect of Gadolinium and Amiloride

This study evaluated the effect of mechanogated membrane ion channel blockers on brain catalase (CAT) activity and thiobarbituric acid reactive substances (TBARS) production after traumatic brain injury (TBI). A weight drop trauma model was used. Controls were sham-operated and received no weight drop. Gadolinium (GAD) or amiloride (AMI) were administered to control and experimental rats (30 min after TBI). Brain CAT activity and TBARS production were measured. When blood vessels were washed out with saline perfusion brain CAT activity significantly increased up to 6 h after trauma, decreasing significantly by 24 h; GAD or AMI administration preserved CAT activity 24 h after TBI. TBARS production increased after trauma, this effect being significantly reversed by GAD or AMI administration. GAD significantly decreased TBARS production in control animals. Mechanogated membrane ion channels may be involved in the genesis of the ionic disruption leading to oxidative stress and other secondary injury processes in head trauma.