Boulton C L, von Haebler D, Heinemann U
Institut für Neurophysiologie, Zentrum für Physiologie und Pathophysiologie, Universität zu Köln, Germany.
Hippocampus. 1992 Apr;2(2):99-106. doi: 10.1002/hipo.450020203.
In order to demonstrate axonal connections preserved in rat temporal cortex slices the authors used rhodamine-dextran-amine as a tracer. The slices contained the neocortical areas Te2 and Te3, the medial and lateral entorhinal cortices (MEC and LEC), the subicular regions, and the dentate gyrus and hippocampus proper. Rhodamine-dextran-amine crystals were placed by microinjection into a given area. Following this local lesioning the dye was permitted to diffuse and migrate intraaxonally in antero- and retrograde directions for about 8 hours. The slices were then formaldehyde-fixed and analyzed by fluorescence microscopy. Most of the known connections within and between the entorhinal cortex and the hippocampus and dentate gyrus were preserved in the slice preparation, provided that the slices were cut with a near horizontal orientation corresponding to plates 99-108 in Paxinos and Watson (1986). Only the lateral perforant path between the LEC and the hippocampus could not be followed to its full extent. The authors conclude that most aspects of the intrinsic synaptic organization of the temporal lobe can be reliably studied in hippocampal-entorhinal cortex slice preparations.
为了展示大鼠颞叶皮质切片中保留的轴突连接，作者使用罗丹明 - 葡聚糖胺作为示踪剂。这些切片包含新皮质区域颞叶第二视觉区（Te2）和颞叶第三视觉区（Te3）、内侧和外侧内嗅皮质（MEC和LEC）、海马下区域以及齿状回和海马本体。通过显微注射将罗丹明 - 葡聚糖胺晶体置于特定区域。在这种局部损伤后，允许染料在轴突内沿 anterograde（顺行）和 retrograde（逆行）方向扩散和迁移约8小时。然后将切片用甲醛固定，并通过荧光显微镜进行分析。只要切片以接近水平的方向切割，对应于Paxinos和Watson（1986年）中的第99 - 108板，内嗅皮质与海马和齿状回之间以及它们内部的大多数已知连接在切片制备中得以保留。只有LEC和海马之间的外侧穿通通路无法完全追踪到。作者得出结论，颞叶内在突触组织的大多数方面可以在海马 - 内嗅皮质切片制备中得到可靠研究。
