VAGUS NERVE STIMULATION AND MODULATION OF PERI-LESIONAL INFLAMMATION AFTER ACUTE BRAIN INJURY IN RATS

Traumatic Brain Injury (TBI) is one of the leading causes of disability and death worldwide. It often causes primary cortex damages and secondary injury resulting to long lasting deficits as neuronal loss mediated by inflammatory processes. Vagus nerve stimulation (VNS), already used for drug-resistant epilepsy in clinics, is a promising therapeutic strategy to reduce central and peripheral inflammation thanks to its anti-inflammatory and neuroprotective properties, it may limit secondary damages. This study aims to explore the effects of acute and chronic VNS after brain injury in rats on neuronal loss, motor recovery and peri-lesional inflammation. TBI is modeled in male Sprague-Dawley rats through controlled cortical impact on the primary motor cortex. We assessed the beneficial effects of such VNS on motor function using cylinder and stepping behavioral tests as well as on lesion severity and neuroinflammation. Our preliminary results did not show that acute VNS enabled motor recovery based on out protocol but showed that the cellular density of pro-inflammatory microglia is reduced in acute vagus nerve-stimulated groups one day after the injury. These findings should be consolidated in a larger number of rats concerning the impact of VNS on perilesional inflammation. We also have the project of adopting a method with higher sensitivity for the detection of potential impact on locomotor function.