REGULATION OF SYNAPTIC PLASTICITY IN VISUAL CORTEX

30多年来，人们一直认为， 出生后早期发育的关键时期产生永久性的 视觉系统的连接、生理和功能的改变 皮层 除了这种神经可塑性的明显相关性， 人类和动物视觉能力的发展， 类似的过程很可能构成了某些学习形式的基础 和记忆的能力。 重要的是，像学习，视觉 皮质可塑性需要神经调节系统的活动。 在确定具体变化方面取得了相当大的进展 在视觉皮层中， 环境，但这些环境背后的详细机制 修改仍然是难以捉摸的。 然而，最近， 了解介导突触兴奋的受体机制 以及发育过程中视觉皮层的抑制作用， 令人兴奋的新机会来研究经验的机制- 依赖大脑改造 该项目的长期目标是 阐明这些经验依赖性皮层可塑性的机制。 体外保存的视皮层切片将用于研究 活动依赖性突触可塑性的基本形式：长期 增强（LTP）和长期抑制（LTD）。 LTP的变化， 发育过程中的LTD与自然发生的 突触修饰 我们的具体目标是调查 LTP和LTD的特性取决于神经调质，这些神经调质是如何 在发育过程中，不同皮质层的特性发生变化， 来理解这些变化背后的机制。 研究 LTP和LTD是如何被监管的， 负责关键时期的机制。

It has been appreciated for over 30 years that visual experience during an early postnatal critical period of development produces permanent modifications of the connectivity, physiology and function of the visual cortex. Besides the obvious relevance of this neural plasticity to the development of visual capabilities in humans and animals, it seems likely that similar processes form the basis for some forms of learning and memory in the adult brain. Significantly, like learning, visual cortical plasticity requires the activity of neuromodulatory systems. Considerable progress has been made in identifying the specific changes in visual cortex that result from rearing the animals in different environments, but the detailed mechanisms that underlie these modifications has remained elusive. Recently, however, advances in understanding the receptor mechanisms that mediate synaptic excitation and inhibition in the visual cortex during development have provided an exciting new opportunity to investigate the mechanisms of experience- dependent brain modification. The long-term goal of this project is to elucidate these mechanisms of experience-dependent cortical plasticity. Slices of visual cortex maintained in vitro will be used to study elementary forms of activity-dependent synaptic plasticity: long-term potentiation (LTP) and long-term depression (LTD). Changes in LTP and LTD during development correlate with changes in naturally-occurring synaptic modification. Our specific aims are to investigate how the properties of LTP and LTD depend on neuromodulators, how these properties change in different cortical layers during development, and to understand the mechanisms which underlie these changes. The study of how LTP and LTD are regulated could yield insights into the mechanisms that are responsible for the critical period.