Equipment for serial-section EM

我的NSERC项目研究的是无脊椎动物模型物种的简单神经细胞系统。 我越来越多地使用我的发现补助金来检查通过计算机辅助三维重建方法从一系列电子显微照片中识别出的已识别神经细胞的电路。 目前，我正在研究果蝇的嗅觉系统，果蝇的其他大脑区域，以及普通海鞘蝌蚪的中枢神经系统，与我们这样的脊椎动物有远亲关系。 我的实验室是这些电子显微镜方法及其在这些和相关物种中应用的世界专家，我们将逐步分析不同大脑区域的突触回路，作为努力理解行为机制的一部分。 第一步是解开已识别的大脑区域的接线图，电子显微镜对这项任务至关重要。 然后，解剖接线图形成了基因解剖和其他分析电路功能的研究的基础。 我们从长时间不间断的图像序列中重建神经细胞回路，为此需要一种新的超薄切片机和可以在40 nm处可靠切割的金刚石刀。 因此，切割合适的系列切片是我们所有工作的基础。 我们在这些技术要求高的程序中的能力吸引了许多合作和访问学员，以及招募我们自己的研究生和博士后HQP。 我们的外部合作既丰富和加速了我在达尔豪西的NSERC计划，也为HQP提供了良好的曝光机会。 为了继续取得进展，我迫切需要更换一台有问题的超薄切片机，它可能会死在我们身上; 28年前购买的一台更老的NSERC机器不再切割切片，而且我在其他地方缺乏可供专用的替代仪器。 这些设备将主要由HQP和技术人员用于切割EM系列，用于研究生或博士后研究，也由本科生助手协助，以及来我的实验室从事这项工作并学习其方法的访客。 一台新的超薄切片机现在对我的实验室在这类研究中保持领先至关重要，并且应该能再提供10年或更长时间的服务。

My NSERC program investigates simple systems of nerve cells in model species of invertebrates. I increasingly use my Discovery grant to examine the circuits of identified nerve cells identified from series of electron micrographs by computer-aided three-dimensional reconstruction methods. Currently I am investigating the olfactory system of the fruit fly, other brain regions in the fly, and the central nervous system of the tadpole of the common sea squirt, distantly related to vertebrate animals like ourselves. My lab is world expert in these electron microscopic approaches and their applications in these and related species, and we will progressively analyse the synaptic circuits of different brain regions, as part of an endeavour to understand the mechanism of behaviour. The first step is to unravel the wiring diagrams of identified brain regions, and electron microscopy is essential for this task. Anatomical wiring diagrams then form the basis for genetic dissection and other studies that assay circuit function. We reconstruct nerve cell circuits from long uninterrupted series of images, and for this need a new ultramicrotome and diamond knives that can cut reliably at 40nm. Cutting suitable series of sections is thus the basis of all our work. Our abilities in these technically demanding procedures attract many collaborations and visiting trainees, as well as recruit our own graduate and postdoc HQP. Our external collaborations both enrich and accelerate my NSERC program at Dalhousie, as well as provide good exposure to HQP. For continued progress I urgently need to replace an ailing ultramicrotome that promises to die on us; a yet older NSERC machine purchased 28 years ago no longer cuts ultrathin sections, and I lack an alternative instrument elsewhere that is available for dedicated use. The equipment will be used mainly by HQP and technical staff to cut EM series, for graduate or postdoctoral research that is also assisted by undergraduate helpers, and by visitors who come to my lab to engage in this work and learn its methods. A new ultramicrotome is now essential for my lab to remain ahead in this type of research, and should give a further 10 or more years of service.