Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the p...Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.展开更多
By in situ hybridization histochemistry, the changes of preprotachykinin (PPT) mRNA expression were examined in the neurons of adjacent thoracal dorsal root ganglion (DRG) after a strong electric stimulation to an int...By in situ hybridization histochemistry, the changes of preprotachykinin (PPT) mRNA expression were examined in the neurons of adjacent thoracal dorsal root ganglion (DRG) after a strong electric stimulation to an intact dorsal cutaneous branch and the cut distal part of left T 9 thoracal spinal nerve of rat. There was a significant increase of the number of neurons expressing PPT mRNA in the ipsilateral T 8, T 9 and T 10 DRG of the animals given electric stimulation to intact spinal nerve branch 24 h after the electric stimulation. The same increase was found in the ipsilateral T 8 and T 10 DRG of the animals given electric stimulation to the distal part of spinal nerve branch. While no change was found in the DRG of the contralateral side of these animals. The present results showed that the antidromic electric stimulation strengthened the biosynthesis of PPT mRNA in adjacent DRG. These findings suggested that there was information transmission across segments between two sensory nerve endings and some bioactive substances such as SP might play important roles in the information transmission across segments of spinal cord.展开更多
基金supported by the National Natural Science Foundation of China,Nos.61534003 (to ZGW) and 61874024 (to ZGW)。
文摘Epidural stimulation of the spinal cord is a promising technique for the recovery of motor function after spinal cord injury.The key challenges within the reconstruction of motor function for paralyzed limbs are the precise control of sites and parameters of stimulation.To activate lower-limb muscles precisely by epidural spinal cord stimulation,we proposed a high-density,flexible electrode array.We determined the regions of motor function that were activated upon epidural stimulation of the spinal cord in a rat model with complete spinal cord,which was established by a transection method.For evaluating the effect of stimulation,the evoked potentials were recorded from bilateral lowerlimb muscles,including the vastus lateralis,semitendinosus,tibialis anterior,and medial gastrocnemius.To determine the appropriate stimulation sites and parameters of the lower muscles,the stimulation characteristics were studied within the regions in which motor function was activated upon spinal cord stimulation.In the vastus lateralis and medial gastrocnemius,these regions were symmetrically located at the lateral site of L1 and the medial site of L2 vertebrae segment,respectively.The tibialis anterior and semitendinosus only responded to stimulation simultaneously with other muscles.The minimum and maximum stimulation threshold currents of the vastus lateralis were higher than those of the medial gastrocnemius.Our results demonstrate the ability to identify specific stimulation sites of lower muscles using a high-density and flexible array.They also provide a reference for selecting the appropriate conditions for implantable stimulation for animal models of spinal cord injury.This study was approved by the Animal Research Committee of Southeast University,China(approval No.20190720001) on July 20,2019.
文摘By in situ hybridization histochemistry, the changes of preprotachykinin (PPT) mRNA expression were examined in the neurons of adjacent thoracal dorsal root ganglion (DRG) after a strong electric stimulation to an intact dorsal cutaneous branch and the cut distal part of left T 9 thoracal spinal nerve of rat. There was a significant increase of the number of neurons expressing PPT mRNA in the ipsilateral T 8, T 9 and T 10 DRG of the animals given electric stimulation to intact spinal nerve branch 24 h after the electric stimulation. The same increase was found in the ipsilateral T 8 and T 10 DRG of the animals given electric stimulation to the distal part of spinal nerve branch. While no change was found in the DRG of the contralateral side of these animals. The present results showed that the antidromic electric stimulation strengthened the biosynthesis of PPT mRNA in adjacent DRG. These findings suggested that there was information transmission across segments between two sensory nerve endings and some bioactive substances such as SP might play important roles in the information transmission across segments of spinal cord.
