Equipment for serial-section EM

我的NSERC计划研究无脊椎动物模式物种的简单神经细胞系统。我越来越多地使用我的发现基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镜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，苍蝇的其他大脑区域，以及普通海鞘蝌蚪的中枢神经系统，它们与我们这样的脊椎动物有很远的亲缘关系。我的实验室是这些电子显微镜方法及其在这些物种和相关物种中的应用方面的世界专家，我们将逐步分析不同大脑区域的突触电路，作为理解行为机制的努力的一部分。第一步是解开已识别的大脑区域的接线图，而电子显微镜对这项任务至关重要。然后，解剖线路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电路，为此需要一种新的超微切割器和钻石刀具，可以在40 nm处可靠地切割。因此，切割一系列合适的截面是我们一切工作的基础。我们在这些技术要求苛刻的程序中的能力吸引了许多合作伙伴和来访的实习生，以及招聘我们自己的研究生和博士后HQP。我们的外部合作丰富和加速了我在Dalhousie的NSERC项目，并提供了对HQP的良好接触。为了继续取得进展，我迫切需要更换一台有问题的超微切割机，它可能会在我们身上死去；28年前购买的一台更老的NSERC机器不再切割超薄切片，而且我在其他地方也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，也有本科生助手的协助，以及来我实验室从事这项工作并学习其方法的访客。一台新的超微切割机现在对我的实验室在这类研究中保持领先地位至关重要，应该会再提供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.