SYNAPTOGENESIS AFTER ISCHEMIC BRAIN INJURY

描述（来自申请人的摘要）：中枢神经系统中的突触 系统选择性地易受缺血性脑损伤，这种损伤可能 对中风后的神经功能障碍至关重要。我们对它的命运知之甚少 即使连接它们的神经元存活了下来。到 检查这个过程，我们已经开发了一个文化模型，允许连续 观察单个突触后树突棘和突触前 小鼠皮层神经元的终末。短暂缺氧， 葡萄糖引起树突棘的快速、谷氨酸受体依赖性损失， 突触末端随后在数小时内返回。我们假设 亚致死性损伤后会形成功能性新突触， 通过重演发育途径。突触结构和功能 将通过共聚焦显微镜和电生理学进行评估。长期 目的是改善中风后的神经功能。使用dissociated 培养的小鼠皮层神经元，我们将研究的时间过程， 损伤后突触发生的电生理学（目的1），评估 钙依赖性细胞骨架重组（目标2），并确定 细胞外影响（星形胶质细胞、雌二醇和营养因子）的作用 已知在发育过程中促进突触发生的因子（Aim 3）。最后， 我们将确定是否突触丢失和恢复的机制发现， 分离的培养物适用于成年小鼠皮层的完整切片， 海马，维持至亚致死氧-葡萄糖后12小时 剥夺（目标4）。长期目标是确定改进的战略 中风后的神经功能

DESCRIPTION (From the applicant's abstract): Synapses in the central nervous system are selectively vulnerable to ischemic brain injury, and this damage may be critical to neurologic dysfunction after stroke. Little is known of the fate of synapses that are lost, even when the neurons that connect them survive. To examine this process, we have developed a culture model that allows continuous observation of individual post-synaptic dendritic spines and presynaptic terminals in mouse cortical neurons. Transient deprivation of oxygen and glucose causes rapid, glutamate receptor-dependent loss of dendritic spines and synaptic terminals followed by their return within hours. We hypothesize that functional new synapses are formed after sublethal injury and that this occurs by recapitulation of developmental pathways. Synaptic structure and function will be assessed by confocal microscopy and electrophysiology. The long-term goal is to improve neurological function after stroke. Using dissociated cultures of murine cortical neurons, we will examine the time course and electrophysiology of synaptogenesis after injury (Aim 1), assess the role of calcium-dependent cytoskeletal reorganization (Aim 2), and determine the effects of extracellular influences (astrocytes, estradiol, and trophic factors) known to promote synaptogenesis during development (Aim 3). Finally, we will determine whether mechanisms of synapse loss and recovery found in dissociated cultures apply to intact slices from adult mouse cortex or hippocampus, maintained up to 12 hours after sublethal oxygen-glucose deprivation (Aim 4). The long-term goal is to identify strategies to improve neurological function after stroke.