Influence of Perineuronal nets on cortical neurons

摘要 从老鼠到人的感觉剥夺已经被证明对神经元有深远的影响 生理、行为和认知过程。这些变化背后的变化是 神经性和非神经性结构。我们的初步数据显示，在一个月的 修剪胡须引起感觉剥夺神经周围神经网络(PN)，一种神经元特有的形式 在小鼠的桶状皮质中，细胞外基质的含量显著减少。失去的是 Pn主要分布在GABA能中间神经元周围。 越来越多的证据表明，快速放电的中间神经元在闭合中起着关键作用。 视觉系统的发育关键期和它们的正常功能是 对大脑皮层的正常生理功能来说是必要的。与剥夺同时存在 Pn的降低我们观察到组织纤溶酶原的增加 溶解PN的激活剂(TPA)。在相同的条件下，小胶质细胞被激活， 因此，我们认为感觉剥夺诱导了小胶质细胞的激活，从而释放tPA和 从而降低Pn。在目标1中，我们将演示感觉剥夺、 小胶质细胞活化和tPA释放导致Pn下降的免疫细胞化学研究 结合体视学的技术。在目标2中，我们将重点介绍生理辊PNS 在改变快速放电中间神经元的内在和突触特性方面有作用。我们会 采用我们的新型小体积孵化器，可随时间降解 PN与双全细胞记录相结合。

Abstract Sensory deprivation from mice to man has been shown to have profound impacts on neuronal physiology, behavior and cognitive processes. Underling these changes are alterations in neuronal and non-neuronal structures. Our preliminary data shows that following one month of whisker trimming induced sensory deprivation the perineuronal net (PN), a neuron specific form of the extra cellular matrix, is significantly reduced in the barrel cortex of mice. The loss of the PN is most prominent around fast-spiking parvalbumin positive GABAergic interneurons. Converging evidence has shown that fast-spiking interneurons play a pivotal role in the closure of the developmental critical period in the visual system and their proper functioning is necessary for the proper physiological functioning of the cortex. Coincident with deprivation induced decreases in the PN we observed increases in the enzyme tissue plasminogen activator (tPA) which dissolves the PN. Under the same conditions microglia become activated, thus we propose that sensory deprivation induces microglia activation which release tPA and thus decrease the PN. In Aim 1 we will demonstrate a causal link between sensory deprivation, microglia activation and tPA release resulting in PN decreases using immunocytochemical techniques in conjunction with stereology. In Aim 2 we will focus on the physiological roll PNs have in modifying the intrinsic and synaptic properties of fast-spiking interneurons. We will employ our novel small volume incubator which allows for time dependent degradation of the PN in conjunction with dual whole-cell recordings.