Terashima T, Takayama C, Ichikawa R, Inoue Y
Department of Anatomy and Embryology, Tokyo Metropolitan Institute for Neuroscience, Fuchu, Japan.
Okajimas Folia Anat Jpn. 1992 Mar;68(6):351-63. doi: 10.2535/ofaj1936.68.6_351.
Reeler, an autosomal recessive mutation in mice, is characterized by abnormal positioning of the neurons in the cerebral cortex. We performed a descriptive analysis on the arborization of dendritic processes of large pyramidal neurons in the motor cortex (hindlimb area) of normal and reeler mice, as seen in the Golgi preparations. In the normal mouse, somata of large pyramidal neurons were located in the layer V, and their apical dendrites ascend vertically to the pial surfaces. Their basal dendrites proceed horizontally or inferiorly. In the reeler mouse, typical large pyramidal neurons with a normal (upright) apical dendrite and a variety of atypical large pyramidal neurons with a disoriented apical dendrite were radially scattered within the motor cortex. Typical large pyramidal neurons occupied the lower half of the motor cortex, whereas atypical large pyramidal neurons were predominantly observed in the upper half of the motor cortex. Atypical large pyramidal neurons were further divided into inverted, tumbled, V-shaped, bipolar and superficial polymorphic cells, as previously reported (Terashima et al., J. Comp. Neurol. 218:314-326, 1983). Superficial polymorphic cells localized in the layer of polymorphic cells and the layer of the large pyramidal cells were characterized by the extremely poor dendritic arborizations and the smooth surface of the dendrites, which suggests development of dendrites of these neurons was deranged by the reeler genetic locus.
“Reeler”是小鼠中的一种常染色体隐性突变，其特征是大脑皮质中神经元的位置异常。我们对正常小鼠和“Reeler”小鼠运动皮质（后肢区域）中大型锥体神经元树突状突起的分支情况进行了描述性分析，观察材料为高尔基染色制剂。在正常小鼠中，大型锥体神经元的胞体位于第V层，其顶端树突垂直向上延伸至软膜表面。它们的基底树突则水平或向下延伸。在“Reeler”小鼠中，具有正常（直立）顶端树突的典型大型锥体神经元和顶端树突方向紊乱的各种非典型大型锥体神经元在运动皮质中呈放射状散在分布。典型大型锥体神经元占据运动皮质的下半部分，而非典型大型锥体神经元主要见于运动皮质的上半部分。非典型大型锥体神经元进一步分为倒置型、翻滚型、V型、双极型和浅表多形型细胞，如先前报道（寺岛等人，《比较神经学杂志》218:314 - 326，1983年）。位于多形细胞层和大型锥体细胞层的浅表多形型细胞的特点是树突分支极少且树突表面光滑，这表明这些神经元树突的发育受到“Reeler”基因位点的干扰。
