Role of NMDA Receptors in the Development of Mammalian Visual Cortex

神经可塑性是指中枢神经系统连接被修改或重新排列的能力，特别是在发育早期的关键时期。在过去的几年里，Stryker博士研究的总体目标是了解神经活动在哺乳动物视觉系统可塑性和发育中的作用。最近对海马长时程增强(LTP)的研究表明，谷氨酸受体的N-甲基-D-天冬氨酸(NMDA)亚型在这种神经活动依赖的突触可塑性中起着至关重要的作用。LTP可塑性在年轻人和成年人的神经系统中都被发现。在这个项目中，Stryker博士和他的同事们将进行几项研究，以阐明NMDA受体在调节活动对猫视皮质可塑性的影响中所起的作用。视觉皮质的可塑性只在发育的早期阶段被发现。研究人员将把NMDA受体拮抗剂注入视皮层；从电生理学角度测量由此产生的受体阻断的特异性；记录NMDA受体阻断对神经活动模式的影响；并研究生理和解剖学上对发育可塑性的影响。史崔克博士对我们的神经系统发育知识做出重大贡献的历史由来已久。这项新工作有望揭示成人中枢神经系统(LTP)可塑性的细胞和分子细节是否也适用于大脑发育中神经元连接的重新安排。

Neural plasticity refers to the ability of central nervous system connections to be modified or rearranged, particularly during a critical period early in development. The overall goal of Dr. Stryker's research over the past several years has been to understand the role of neural activity in mammalian visual system plasticity and development. Much recent evidence from studies of long-term potentiation (LTP) in the hippocampus suggests that the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor plays a crucial role in this neural activity-dependent synaptic plasticity. LTP plasticity is found in both young and adult nervous systems. In this project, Dr. Stryker and his colleagues will conduct several studies to elucidate the role of NMDA receptors in mediating the effects of activity on the plasticity of the cat visual cortex. Plasticity in the visual cortex is only found during an early stage of development. The investigators will infuse NMDA-antagonists into the visual cortex; measure electrophysiologically the specificity of the receptor blockade so produced; record the effects of NMDA- receptor blockade on patterns of neural activity; and study physiologically and anatomically effects on plasticity in development. Dr. Stryker has a long history of making significant contributions to our knowledge of nervous system development. This new work promises to reveal whether the cellular and molecular details of plasticity in the adult central nervous system (LTP), now receiving enormous research attention, apply also to the rearrangement of neuronal connections in brain development.