POSTNATAL PLASTICITY AND RECOVERY FROM BRAIN DAMAGE

产后可塑性和脑损伤的恢复

• 批准号: 3408107
• 负责人: PETER R HUTTENLOCHER
• 金额: $ 8.41万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-01 至 1995-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3408107
• 关键词: axon; botulinum toxins; brain mapping; cerebral cortex; developmental neurobiology; experimental brain lesion; hemispherectomy; histochemistry /cytochemistry; innervation; laboratory rat; laminectomy; neural plasticity; neuromuscular blocking agents; neurons; newborn animals; paralysis; psychomotor disorders; pyramidal tracts; sensorimotor system; sensory feedback; statistics /biometry

It is the purpose of this study to explore the plasticity of, developing cerebral cortex during the postnatal period, using the pyramidal motor system of the rat as a model. In the proposed experiments, effects of restriction of motor activity and of sensory .feedback during the postnatal period on number and cortical location of corticospinal (CS) neurons will be studied. The experiments are a direct, systematic extension of work completed during the 01-03 years of the project. During this first phase, it was found that unilateral forelimb restraint between age 5 and 30 days leads to an increase in CS connections and in enlargement of the cortical area of representation of the restrained limb. The proposed studies address several unresolved issues related to effects of the periphery on the anatomy of the pyramidal motor system: 1) What are the age limits of the observed effects? 2) What is the minimum period of limb restraint that produces an effect? 3) Does limb paralysis by neuromuscular blockade produce similar effects? 4) what is the effect of elimination of sensory feedback, both in animals without and with limb restraint? 5) Are increased numbers of CS connections after limb restraint associated with decreased normal cell death in the target zone of CS axons, thereby making more targets available for innervation? 6) Are the same cortical neurons that form an, uncrossed CS tract after neonatal hemispherectomy involved in the formation of extra crossed connections after limb restraint? The basic methodology will be that of identification of CS neurons by unilateral spinal cord injection of a retrograde tracer, followed by computer-- assisted quantitation of number of pyramidal tract cells and construction of maps of cortical representation. The proposed studies are expected to provide important information, concerning the limits and mechanisms of plasticity in the developing motor system. Such knowledge is of major importance for the understanding: of variations in normal development and of developmental errors.

这是这项研究的目的，探讨了， 在产后期间开发脑皮质，使用 大鼠的锥体运动系统作为模型。 在提议中 实验，运动活动限制和感觉的影响 。 将研究皮质脊髓（CS）神经元。 实验是 直接的，系统地扩展完成在01 - 03年期间完成的工作 项目。 在第一阶段，发现单侧 5至30天之间的前肢约束导致CS增加 连接和扩大的皮层代表区域 约束的肢体。 拟议的研究涉及几个尚未解决的 与外围对外围的影响有关的问题 金字塔运动系统：1）观察到的年龄限制是多少 效果？ 2）产生的最低肢体约束时期是多少 影响？ 3）神经肌肉阻滞的肢体瘫痪会产生相似的 效果？ 4）消除感觉反馈的影响是什么？ 在没有肢体约束的动物中？ 5）数量增加 肢体约束后与正常细胞减少相关的CS连接 CS轴突的目标区域死亡，从而实现更多目标 可用于神经？ 6）是形成AN的皮质神经元相同的 新生半球切除术后未划过的CS道参与 肢体约束后形成额外的交叉连接？基本 方法将是单侧鉴定CS神经元的方法 注入逆行示踪剂的脊髓，然后是计算机 - 辅助定量锥体区域和构造 皮质表示地图。 预计拟议的研究将提供重要信息， 关于发展中可塑性的极限和机制 电机系统。 这种知识对 理解：正常发展和发展的变化 错误。