Corticospinal development after cortical inactivation

描述（由申请人提供）：拟议实验的目的是了解皮质活动在猫皮质脊髓（CS）系统发育中的作用。猫的CS系统在出生时是不成熟的，在出生后的早期生活中继续发展。发育过程中的神经活动似乎在确定CS系统的地形组织以及在脊髓CS轴突与其神经元靶点之间建立特定的功能连接方面起着至关重要的作用。拟议的实验将确定神经营养因子BDNF和NT-3在发育过程中的地形分布，相对于CS发育的关键时期。在第二个系列的实验中，感觉-运动皮层将在发育早期被抑制。然后，进行限制性运动疗法或锥体束刺激，为期四周。这一目标将决定康复方案在引导CS向更正常模式发展方面的功效。由于人类CS异常发育往往导致永久性残疾，了解导致CS异常发育的因素，以及行为干预在引导CS系统向更正常发育方面的功效，具有很高的临床意义。

DESCRIPTION (provided by applicant): The goal of the proposed experiments is to understand the role of cortical activity in the development of the corticospinal (CS) system in the cat. The cat CS system is immature at birth and continues to develop during early postnatal life. Neural activity during development appears to play a vital role in determining the topographic organization of the CS system and in establishing specific, functional connections between CS axons and their neuronal targets in the spinal cord. The proposed experiments will determine the topographic distribution of the neurotrophins BDNF and NT-3 during development, with respect to the critical period for CS development. In a second series of experiments, sensory-motor cortex will be silenced early in development. Then, either constraint-induced movement therapy or pyramidal tract stimulation will be implemented for four weeks. This aim will determine the efficacy of the rehabilitation regimens in guiding CS development toward a more normal pattern. Since abnormal CS development in humans often results in permanent disabilities, understanding the factors that cause abnormal CS development, and the efficacy of behavioral interventions in guiding the CS system toward a more normal development, is highly clinically significant.