Animal Physiology, FB18, University of Kassel, Kassel, Germany.
J Comp Neurol. 2010 Oct 15;518(20):4113-33. doi: 10.1002/cne.22471.
The cockroach Leucophaea maderae is an established model in circadian rhythm research. Its circadian clock is located in the accessory medulla of the brain. Pigment-dispersing factor-immunoreactive (PDF-ir) neurons of the accessory medulla act as circadian pacemakers controlling locomotor activity rhythms. To characterize the neuronal network of the circadian system in L. maderae, the PDF-ir neurons were implemented into a standardized three-dimensional atlas of the cockroach brain. Serial confocal images from 20 wholemount brains were used for the construction of the atlas comprising 21 neuropils. Two different standardization protocols were employed: the iterative shape averaging (ISA) procedure using an affine transformation followed by iterative non-rigid registrations, and the virtual insect brain (VIB) protocol employing local non-rigid transformations after global and local rigid transformations. Quantitative analysis of the 20 brains revealed that volumes of the accessory medulla are directly correlated with the volumes of the medulla, the protocerebral bridge, and the upper division of the central body, suggesting functional connections among these neuropils. For a standardized reconstruction of the circadian pacemaker network, the ISA protocol was used to register PDF-ir neurons in the standard cockroach brain. The registration revealed that two PDF-ir arborization areas in the brain are highly interconnected with other PDF-ir projection sites and appear to be contacted both by fibers in the posterior and the anterior optic commissures. The distances between PDF-ir branching areas show specific numerical relationships that might be physiologically relevant for temporal encoding.
蜚蠊 Leucophaea maderae 是昼夜节律研究中的成熟模型。其生物钟位于脑的附加 medulla 中。附加 medulla 中的色素扩散因子免疫反应 (PDF-ir) 神经元作为生物钟起搏器，控制着运动活动节律。为了描述 L. maderae 昼夜节律系统的神经元网络，将 PDF-ir 神经元纳入了蜚蠊脑的标准化三维图谱中。使用来自 20 个全脑的连续共聚焦图像构建了图谱，图谱包含 21 个神经节。采用了两种不同的标准化方案：使用仿射变换的迭代形状平均 (ISA) 程序，然后进行迭代非刚性配准，以及采用全局和局部刚性变换后局部非刚性变换的虚拟昆虫脑 (VIB) 协议。对 20 个大脑的定量分析表明，附加 medulla 的体积与 medulla、protocerebral bridge 和中央体的上部分的体积直接相关，表明这些神经节之间存在功能连接。为了标准化重建昼夜节律起搏器网络，使用 ISA 协议在标准蜚蠊脑中注册 PDF-ir 神经元。注册结果表明，脑中的两个 PDF-ir 分支区域与其他 PDF-ir 投射部位高度相互连接，并且似乎同时受到后和前视神经束纤维的接触。PDF-ir 分支区域之间的距离显示出特定的数值关系，这可能对时间编码具有生理相关性。
