Spine Dynamics Underlying Ocular Dominance Plasticity

描述(申请人提供)：在发育中的神经系统中，最初混杂的突触连接被活动依赖的机制重塑，轴突加强了它们与一些目标的联系，同时完全与其他目标断开了联系。在新皮质中，这一过程在发育中的初级视觉皮质中得到了最彻底的研究，在那里，双眼活动的去相关显著减少了皮质的双目视觉。大脑皮层生理学的这些功能变化被广泛认为是建立在突触连接效力的长期变化上的。然而，突触可塑性导致皮质回路功能改变的具体机制仍然不清楚。这项工作的主要目的是确定在大脑皮质回路的哪个部位首次观察到双眼反应中经验依赖性的变化，追踪这些变化随时间的进展，并检验这些变化植根于突触连接的解剖学变化的假设。为了解决这些问题，将使用双光子激光扫描显微镜、本征信号光学成像和单单位记录等技术来绘制电路可塑性图，并跟踪体内突触连接的变化。

DESCRIPTION (provided by applicant): In the developing nervous system, initially promiscuous synaptic connections are remodeled by activity-dependent mechanisms, with axons strengthening their connections with some targets while completely disconnecting from others. In the neocortex, this process has been most thoroughly studied in the developing primary visual cortex, where decorrelating the activity of the two eyes dramatically reduces cortical binocularity. These functional changes in cortical physiology are widely accepted to be anchored in long-lasting changes in the efficacy of synaptic connections. However, the specific mechanisms by which synaptic plasticities lead to changes in the function of cortical circuitry remain elusive. The major objective of the work proposed here is to determine where in the cortical circuit experience-dependent changes in binocular responses are first observed, track the progression over time, and test the hypothesis that these changes are anchored in anatomical changes in synaptic connectivity. To address these questions, techniques such as 2-photon laser scanning microscopy, intrinsic signal optical imaging, and single-unit recordings, will be used to map circuit plasticity and follow changes in synaptic connectivity in vivo.