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CS系统在出生时不成熟，并在出生后早期继续发育。发育过程中的神经活动似乎在确定CS系统的地形组织和在脊髓中CS轴突与其神经元靶点之间建立特定的功能性连接中起着至关重要的作用。拟议的实验将确定地形分布的神经营养因子BDNF和NT-3在发展过程中，相对于CS发展的关键时期。在第二个系列的实验中，感觉运动皮层将在发育早期被沉默。然后，将进行为期四周的强制性运动疗法或锥体束刺激。这一目标将确定康复治疗方案在引导CS向更正常模式发展方面的有效性。由于异常CS发展在人类往往会导致永久性残疾，了解导致异常CS发展的因素，以及行为干预在引导CS系统向更正常的发展的功效，是非常临床意义。

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.