Journal of neurotrauma
-
Journal of neurotrauma · Oct 2019
Cathodal Transcranial Direct-Current Stimulation Selectively Decreases Impulsivity after Traumatic Brain Injury in Rats.
Traumatic brain injury (TBI) often results in chronic psychiatric-like symptoms. In a condition with few therapeutic options, neuromodulation has emerged as a promising potential treatment avenue for these individuals. The goal of the current study was to determine if transcranial direct-current stimulation (tDCS) could treat deficits of impulsivity and attention in rats. ⋯ Treatment with tDCS selectively reduced impulsivity in the TBI group, and the greatest recovery occurred in the rats with the largest deficits. With these data, we have established a rat model for studying the effects of tDCS on psychiatric-like dysfunction. More research is needed to determine the mechanism of action by which tDCS-related gains occur.
-
Journal of neurotrauma · Oct 2019
Transcranial Magnetic Stimulation-Electroencephalography Measures of Cortical Neuroplasticity Are Altered after Mild Traumatic Brain Injury.
While the potential long-term side effects of mild traumatic brain injury (mTBI) are becoming increasingly recognized, the associated neurophysiological mechanisms remain poorly understood. However, changes in cortical inhibitory function and neuroplasticity have been suggested as possible contributing factors. The current study applied transcranial magnetic stimulation (TMS) in conjunction with electroencephalography (combined TMS-EEG) to investigate further the effects of mTBI on these processes. ⋯ Inhibition of the TMS-evoked EEG potential after application of SICI and LICI was not different between groups. In contrast, the inhibitory effects of cTBS on both P30 (p < 0.05) and N45 (p = 0.04) TEP components was significantly increased in patients, with the modulation of N45 in patients significantly related to the time since injury (p = 0.04). While these results provide further evidence that inhibitory circuits involving γ-aminobutyric acid (GABA) are modified after mTBI, they place greater emphasis on the plasticity of inhibitory networks involving the GABAA receptor subtype.
-
Journal of neurotrauma · Oct 2019
Controlled cortical impact leads to cognitive and motor function deficits that correspond to cellular pathology in a piglet traumatic brain injury model.
Traumatic brain injury (TBI) is a leading cause of death and disability in the United States, with children who sustain a TBI having a greater risk of developing long-lasting cognitive, behavioral, and motor function deficits. This has led to increased interest in utilizing large animal models to study pathophysiologic and functional changes after injury in hopes of identifying novel therapeutic targets. In the present study, a controlled cortical impact (CCI) piglet TBI model was utilized to evaluate cognitive, motor, and histopathologic outcomes. ⋯ Additionally, gait analysis revealed significant increases in cycle time and stance percent, significant decreases in hind reach, and a shift in the total pressure index from the front to the hind limb on the affected side, suggesting TBI impairs gait and balance. Pigs were sacrificed 28 days post-TBI and histological analysis revealed that TBI lead to a significant decrease in neurons and a significant increase in microglia activation and astrogliosis/astrocytosis at the perilesional area, a significant loss in neurons at the dorsal hippocampus, and significantly increased neuroblast proliferation at the subventricular zone. These data demonstrate a strong relationship between TBI-induced cellular changes and functional outcomes in our piglet TBI model that lay the framework for future studies that assess the ability of therapeutic interventions to contribute to functional improvements.