Effects of Electric Cortical Stimulation (ECS) and Transcranial Direct Current Stimulation (tDCS) on Rats With a Traumatic Brain Injury

Abstract

Objective To evaluate the effects of electric cortical stimulation (ECS) and transcranial direct current stimulation (tDCS) on motor and cognitive function recovery and brain plasticity in focal traumatic brain injury (TBI) of rats model. Methods Forty rats were pre-trained to perform a single pellet reaching task (SPRT), rotarod test (RRT), and Y-maze test for 14 days, then a focal TBI was induced by a weight drop model on the motor cortex. All rats were randomly assigned to one of the three groups: anodal ECS (50 Hz and 194 μs) (ECS group), tDCS (0.1 mA, 50 Hz and 200 μs) (tDCS group), and no stimulation as a control group. Four-week stimulation, including rehabilitation, was started 3 days after the operation. SPRT, RRT, and Y-maze were measured from day 1 to day 28 after the TBI was induced. Histopathological and immunohistochemistry staining evaluations were performed at 4 weeks. Results SPRT was improved from day 7 to day 26 in ECS, and from day 8 to day 26 in tDCS compared to the control group (p<0.05). SPRT of ECS group was significantly improved on days 3, 8, 9, and 17 compared to the tDCS group. Y-maze was improved from day 8 to day 16 in ECS, and on days 6, 12, and 16 in the tDCS group compared to the control group (p<0.05). Y-maze of the ECS group was significantly improved on day 9 to day 15 compared to the tDCS group. The c-Fos protein expression was better in the ECS group and the tDCS group compared to the control group. Conclusion Electric stimulation in rats modified with a focal TBI is effective for motor recovery and brain plasticity. ECS induced faster behavioral and cognitive improvements compared to tDCS during the recovery period of rats with a focal TBI.

Keywords

• Electric cortical stimulation
• Transcranial direct current stimulation
• Traumatic brain injuries
• Rehabilitation
• Function recovery