Introduction of adeno-associated viral vectors into the rat sciatic nerve for further optogenetic study

Peripheral nerve injuries are a significant clinical problem of our time, especially in the context of wartime, which is often accompanied by significant physiological disorders or loss of limb functionality. According to statistical data, peripheral nerve injury in civilian patients with trauma is about 2.8%, and there are no relevant data regarding military personnel. Unfortunately, the current conventional morphological and functional nerve repair approaches do not provide stable results and still require further improvement. In this study, we assessed the efficacy of introducing adeno-associated viral vectors that provide expression of the light-sensitive ion channel channelrhodopsin as a potential method for monitoring the regeneration process of the damaged peripheral nerve. The photoactivation of such ion channels in the recovered peripheral nerves could potentially allow the mapping of the areas of innervation recovery. First, we performed surgery with the injection of AAV1-CAG-ChR2-mCherry vectors under the epineural membrane at the proximal end of the sciatic nerve towards the spinal cord. Five weeks after surgery, the expression of channelrhodopsin in the peripheral terminals was tested by stimulation with 450 nm light, resulting in the withdrawal of the operated limb from the glass surface. The results showed that the injection of adeno-associated viral vectors has diagnostic potential in the field of peripheral nerve injury.