The Effect of Electric Cortical Stimulation after Focal Traumatic Brain Injury in Rats

Abstract

ObjectiveTo evaluate the effects of electric cortical stimulation in the experimentally induced focal traumatic brain injury (TBI) rat model on motor recovery and plasticity of the injured brain.MethodTwenty male Sprague-Dawley rats were pre-trained on a single pellet reaching task (SPRT) and on a Rotarod task (RRT) for 14 days. Then, the TBI model was induced by a weight drop device (40 g in weight, 25 cm in height) on the dominant motor cortex, and the electrode was implanted over the perilesional cortical surface. All rats were divided into two groups as follows: Electrical stimulation (ES) group with anodal continuous stimulation (50 Hz and 194 µs duration) or Sham-operated control (SOC) group with no electrical stimulation. The rats were trained SPRT and RRT for 14 days for rehabilitation and measured Garcia's neurologic examination. Histopathological and immunostaining evaluations were performed after the experiment.ResultsThere were no differences in the slice number in the histological analysis. Garcia's neurologic scores & SPRT were significantly increased in the ES group (p<0.05), yet, there was no difference in RRT in both groups. The ES group showed more expression of c-Fos around the brain injured area than the SOC group.ConclusionElectric cortical stimulation with rehabilitation is considered to be one of the trial methods for motor recovery in TBI. However, more studies should be conducted for the TBI model in order to establish better stimulation methods.

A new model of experimental hemispherotomy in young adult Rattus norvegicus: a neural tract tracing and SPECT in vivo study

“…29,46,55 Advantages of the experimental model of hemispherotomy proposed here include the opportunity to study the morphology and functional characteristics of novel neural connections arising from adaptive neuroplasticity in the disconnected brain through the emergence of new subcortical projections and their inputs to the ventral horn of the spinal cord. In addition, we should highlight the functional role played by neuronal activity in the basal nuclei, brainstem-descending reticular-spinal projections, and cerebellum in recovering animals; neuronal and myelin plasticity; 11 electrical stimulation; 27,54 and neurophysiological mechanisms 42 previously suggested by several researchers. 34,43,46,49 The current model of hemispherotomy also enables the development of new rehabilitation strategies in rodents undergoing experimental hemispherotomy for the improvement of postsurgical recovery after hemispheric injuries, and it allows us to describe the neurological bases of this surgical therapeutic intervention in children with pharmacologically refractory epilepsy.…”

Neurostimulation for traumatic brain injury

“…Direct cortical stimulation can induce plasticity in somatosensory areas of macaque monkeys, and cortical stimulation enhances functional recovery and cortical plasticity in the setting of neural injury, such as stroke in squirrel monkeys. 69,119,144,162 Stimulation during rehabilitation following motor cortex injury improves motor function in both rats and primates. 119,162 In animal experiments using intracortical microstimulation, cortical surface electrodes stimulating the motor cortex at subthreshold levels during rehabilitation after focal motor cortex ischemia can increase forelimb function.…”

“…69,119,144,162 Stimulation during rehabilitation following motor cortex injury improves motor function in both rats and primates. 119,162 In animal experiments using intracortical microstimulation, cortical surface electrodes stimulating the motor cortex at subthreshold levels during rehabilitation after focal motor cortex ischemia can increase forelimb function. 69,119 This functional improvement following motor cortex infarction is induced by restoration of movement representation in peri-infarct areas, as well as the emergence of novel representations.…”

A Review of Neuromodulation in the Neurorehabilitation

“…New therapeutic strategies are needed for treatment of neurological functional deficits followingtraumatic or ischemic brain injury. Neuromodulation approach has been employed to treat stroke and TBI in animal models [7][8][9][10][11] and clinical studies [12][13][14], with preliminary data showing that neurostimulation may lead to functional improvement in the setting of brain injuries. A few animal studies in non-human primates have observed thatcortical stimulationenhances functional recovery and cortical plasticity after neural injury induced by stroke [7][8][9].…”