Changes in neuropeptide Y gene expression in the spinal cord of chronic constrictive injury model rats after electroconvulsive stimulation

Some reports have shown that electroconvulsive shock therapy (ECT) is effective for treating refractory neuropathic pain. However, its mechanism of action remains unknown. We have previously shown that electroconvulsive shock (ECS) improved thermal hypersensitivity in chronic constrictive injury (CCI) model rats and simultaneously elevated the neuropeptide Y (NPY) expression in the brain of these rats. In this study, we examined changes in the expression of NPY in the spinal cord of a CCI model. The rat model of CCI was established by ligating the left sciatic nerve. ECS was administered to the rats once daily for six days on days 7-12 after the operation using an electrical stimulator. RT-PCR was used to measure NPY mRNA expression in both the right and left L5 dorsal spinal cords on the 14th day after the operation. NPY gene expression was decreased in the dorsal spinal cords after ECS; however, no differences in NPY expression were observed between the right and left side of dorsal spinal cords, suggesting that the effect of changes in NPY expression after ECS on the improvement of neuropathic pain is not directly related to the spinal cord, but mainly to the upper central nerves.