Stoneham Emily T, Sanders Erin M, Sanyal Mohima, Dumas Theodore C
Molecular Neuroscience Department, George MasonUniversity, Fairfax, Virginia 22030, USA.
Biol Bull. 2010 Oct;219(2):81-99. doi: 10.1086/BBLv219n2p81.
Overproduction and pruning during development is a phenomenon that can be observed in the number of organisms in a population, the number of cells in many tissue types, and even the number of synapses on individual neurons. The sculpting of synaptic connections in the brain of a developing organism is guided by its personal experience, which on a neural level translates to specific patterns of activity. Activity-dependent plasticity at glutamatergic synapses is an integral part of neuronal network formation and maturation in developing vertebrate and invertebrate brains. As development of the rodent forebrain transitions away from an over-proliferative state, synaptic plasticity undergoes modification. Late developmental changes in synaptic plasticity signal the establishment of a more stable network and relate to pronounced perceptual and cognitive abilities. In large part, activation of glutamate-sensitive N-methyl-d-aspartate (NMDA) receptors regulates synaptic stabilization during development and is a necessary step in memory formation processes that occur in the forebrain. A developmental change in the subunits that compose NMDA receptors coincides with developmental modifications in synaptic plasticity and cognition, and thus much research in this area focuses on NMDA receptor composition. We propose that there are additional, equally important developmental processes that influence synaptic plasticity, including mechanisms that are upstream (factors that influence NMDA receptors) and downstream (intracellular processes regulated by NMDA receptors) from NMDA receptor activation. The goal of this review is to summarize what is known and what is not well understood about developmental changes in functional plasticity at glutamatergic synapses, and in the end, attempt to relate these changes to maturation of neural networks.
发育过程中的过度生成和修剪是一种在种群中的生物体数量、许多组织类型中的细胞数量，甚至单个神经元上的突触数量中都能观察到的现象。发育中的生物体大脑中突触连接的塑造受其个人经历的引导，这在神经层面上转化为特定的活动模式。谷氨酸能突触处的活动依赖性可塑性是发育中的脊椎动物和无脊椎动物大脑中神经网络形成和成熟的一个组成部分。随着啮齿动物前脑的发育从过度增殖状态转变，突触可塑性会发生改变。突触可塑性的后期发育变化标志着更稳定网络的建立，并与明显的感知和认知能力相关。在很大程度上，谷氨酸敏感的N-甲基-D-天冬氨酸（NMDA）受体的激活在发育过程中调节突触稳定，并且是在前脑发生的记忆形成过程中的一个必要步骤。组成NMDA受体的亚基的发育变化与突触可塑性和认知的发育改变相吻合，因此该领域的许多研究都集中在NMDA受体的组成上。我们提出，还有其他同样重要的发育过程会影响突触可塑性，包括NMDA受体激活上游（影响NMDA受体的因素）和下游（由NMDA受体调节的细胞内过程）的机制。这篇综述的目的是总结关于谷氨酸能突触功能可塑性的发育变化已知的和尚未充分理解的内容，并最终尝试将这些变化与神经网络的成熟联系起来。
