Neural Tracing Study Of Regeneration Nerve Of Artificial-autonomic Never Anastomosis

Kinds of reasens caused spinal cord injury(SCI) is a difficult medical problem, in addition, spina bifida is a disfigurement of birth. The information from the nerve disfigurement epidemic date in our country shows;the rat of the spina bifida is eight point five every ten thousands infant, one every one thousand in Ameerica,about four thousands patients every year. About eighty to eight-five percents spina bifida patients with neurogenic bladder and bowel dysfunctions. Bladder and bowel dysfunction not only influence the life of patients, but also caused infection and renal failure, is the leading cause of death in paraplegic patients. Spinal cord injury caused neurogenic bladder, the reseon which made paraplegic patients die. In addition, about 500 thousands paraplegic patients need to rebuild function of bladder,and the figure is still increasing on speed of 50 thousands every year.Today, there are many methods can be used to treat the neurogenic voiding dysfunction after SCI, including corrdination destrusor muscle and sphincters through medicament,clean intermittent catheterization, surgical voiding such as reinnervating of the bladder and rebuilding of bladder and urethra, electric stimulation to micturate,et al. But these means can not renew the micturate function of bladder. The electric stimulation of sacral ventral roots was regarded as an only method which can cure neurogenic bladder and renew functional micrurtion, however, has not been a choice of the treatment for the majority of SCI victims, because it involves in expensive, the clinical result is far from universal,destroy some natural functions of sense and effect character function and so on.Xiao CG proposed in 1990 to establish an artificial skin-CNS-bladder reflex pathway below the site of spinal cord lesion as a means of restoring controllable micturition after SCI,made satisfacted effect in clinic therapy of bladder and bowel dysfunctions caused by paraplegia in 1995,and get another success in which curing bladder and bowel dysfunctions caused by spina bifida in 2000. Artificial somatic-autonomic reflex arc provided new mothed for the treatment of neurogenic bladder. Many studies have illustrated the functional mechanism of it,but there not adequate morphologic evidence how the axon of the forein neuron through the anastomosis site and along the previous path of somatic nerve to the pelvic ganglia. The object of this study is to provid morphologic evidence whether the axon of the forein neuron can through the anastomosis site and grow to the penlvic ganglia after operation in rat,and then further illustrated theoretical foundation of artificial somatic-autonomic reflex arc.Part I The morphologic study of anastomosis site after somatic-autonomi nerve were anastomosed.Objective: To observe the regenerative nerve fiber whether or not through the anastomosis site after the artificial somatic-autonomic reflex pathway was established.Method: After the artificial somatic-autonomic reflex pathway rat model was established six months later. Appling the antegrate tracing method,the DiI-DMSO(thickness is 5%) was injected into the anterior horn at the left L4 segment of spinal cord,taking out T12-L1 segment spinal cord fourteen daies later,and a segment nerve of anastomosis site about 1cm long. Infestated slice up the spinal cord and vertical the nerve,after that,observe the result under the light and fluorescent microscope. Result: After DiI-DMSO was injected into the anterior horn at the left L4 segment of spinal cord,the light enlargement on the anastomosis site,LM observation on the anastomosis site showed the slight enlargement on it,not conglutined with other nerve fiber around it,near segment is slight wider then far segment at the anastomosis site,nerve fiber was arranged regular. FM observation showed a clusters of orange fluorescence on different brightness,bundles of flouorescence drops were seen under higher times FM,they are axons which labeled by DiI possible.Conclusion: After the artificial somatic-autonomic reflex pathway was established, the regenerative nerve fiber can through the anastomosis site and regrowe along previous path of somatic nerve.Part II The dynamic observation on how DiI though the anastomosis site after the artificial somatic-autonomic reflex pathway was establishedObjective: To futher validate how the regenerative nerve fiber which labeled by DiIthrough the anastomosis site after the artificial somatic-autonomic reflex pathway in rat was established.Method: After the artificial somatic-autonomic reflex pathway in rat was established,four months later,model rat was fixed by paraformaldehyde and taken out a segment of anastomosis site,tracer DiI was injected into the side which 2mm away from the site by a injecter with a miniglasss tube on it,then observe on a same slice under FM on 5 day, 10 day, 15 day,20 day respectively.Result: FM showed clusters of orange flouorescence emit form the injection site after tracer was injected 5 days later, flouorescence keep extending to anastomosis site 10 days later ,it arrived and theoughed the site after 15 and 20 days later.Conclusion: After the artificial somatic-autonomic reflex pathway was established,the regenerative nerve fiber which labeled by DiI can through the anastomosis site and keep growing along this artificial bridge.