Foster R E, Donoghue J P, Ebner F F
Exp Brain Res. 1981;43(3-4):330-6. doi: 10.1007/BF00238375.
The size, shape and laminar position of efferent neurons in the parietal cortex of the Virginia opossum were identified using the method of retrograde transport of horseradish peroxidase (HRP). Injection of HRP into the spinal cord, dorsal column nuclei or pontine nuclei leads to labeling of cells in layer V and occasionally in layer VI, while a large injection of HRP in the dorsal thalamus labels many cells in layer VI, with fewer cells in layer V. HRP injections in the SSM cortex label cells in layers II-VI of ipsilateral and contralateral cortical areas. However, the majority of these cortico-cortical cells are found in the supragranular layers. Examination of the size, shape and laminar position of retrogradely labeled layer V neurons after injections in each of these areas suggests that none of these features can be used to predict accurately the projection target of individual neurons. We conclude that the laminar organization of efferent cells of the opossum parietal cortex is very similar to that seen in the neocortex of other mammals, despite the complete coalescence of somatic sensory (SI) and motor (MI) areas in the opossum.
利用辣根过氧化物酶（HRP）逆行运输法确定了弗吉尼亚负鼠顶叶皮质传出神经元的大小、形状和分层位置。将HRP注入脊髓、背柱核或脑桥核会导致V层细胞被标记，偶尔VI层也会被标记；而在背侧丘脑大量注射HRP会标记VI层中的许多细胞，V层中的细胞较少。在体感运动混合皮质（SSM皮质）注射HRP会标记同侧和对侧皮质区域II - VI层中的细胞。然而，这些皮质 - 皮质细胞大多位于颗粒上层。对在这些区域中每个区域注射后逆行标记的V层神经元的大小、形状和分层位置进行检查表明，这些特征都不能准确预测单个神经元的投射靶点。我们得出结论，尽管负鼠的躯体感觉区（SI）和运动区（MI）完全融合，但负鼠顶叶皮质传出细胞的分层组织与其他哺乳动物新皮质中的情况非常相似。
