PROPERTIES OF CENTRAL AXONS AT PERIPHERAL TARGETS

外周靶点中央轴突的特性

• 批准号: 3410259
• 负责人: KENNETH J. SMITH
• 金额: $ 9.56万
• 依托单位: EASTERN VIRGINIA MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-07-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3410259
• 关键词: afferent nerve; axon; denervation; dorsal root; electromyography; electron microscopy; histology; laboratory rat; microscopy; motor neurons; myofibrils; nervous system regeneration; neurofilament; neuromuscular system; neurophysiology; peripheral nervous system; somesthesis; striated muscles; synapses; ventral roots

It is now well established that although central nerve fibers will not elongate over long distances within the adult mammalian central nervous system (CNS), they readily do so within the peripheral environment of nerves inserted into the CNS. Despite the variety of neurons with this property, there has so far been no report of whether the regenerating axons are induced by their peripheral environment and target organs to develop terminal specializations capable of sensory or motor transduction. If such receptors are formed, then peripheral nerve grafts may be of value in restoring function to limbs rendered paralysed and numb by spinal cord injury. Significantly, our preliminary experiments have established that effective synapses are formed on denervated skeletal muscle by central fibers regenerating along ventral roots replanted into the lateral column. Central nerve fibers will be led from the spinal cord via replanted ventral and dorsal roots to reinnervate either denervated skeletal muscle or denervated skin. The ventral and dorsal roots will be replanted into the ventro-lateral and dorso-lateral columns respectively, either near to their normal junction or, via a graft, to a site above the supposed location of an injury to the spinal cord. After 4-8 months the rats will be assessed physiologically and histologically to determine a) whether motor or sensory terminals have formed, b) the identities of the fibers involved, and c) whether the regenerating neurons contribute to useful motor or sensory function. Successful motor reinnervation will be assessed, in part by determining the presence of contractions of the appropriate muscles upon direct stimulation of the replanted ventral root, and upon indirect (synaptic) activation of motoneurons. The return of muscle reinnervation will also be monitored serially using EMG recordings. Successful sensory reinnervation will be determined, in part, by mapping the sensory fields of individual fibers teased from the replanted roots, and by determining the presence of central responses evoked by sensory stimulation. Another experiment will examine whether axonal damage is a prerequisite to neurite production.

现在已经确定，虽然中枢神经纤维会

项目成果

End-tidal carbon dioxide (CO2) monitoring in small animals.

小动物潮气末二氧化碳 (CO2) 监测。

• DOI: 10.1016/0361-9230(89)90116-0
• 发表时间: 1989
• 期刊: Brain research bulletin
• 影响因子: 3.8
• 作者: Smith,KJ;Felts,PA
• 通讯作者: Felts,PA

Reinnervation of denervated skeletal muscle by central neurons regenerating via ventral roots implanted into the spinal cord.

通过植入脊髓的腹侧根再生的中枢神经元对去神经骨骼肌进行神经再支配。

• DOI: 10.1016/0006-8993(91)90936-p
• 发表时间: 1991
• 期刊: Brain research
• 影响因子: 2.9
• 作者: Smith,KJ;Kodama,RT
• 通讯作者: Kodama,RT