猫运动皮层内篮状细胞的立体重构,递质性质及突触分布

用细胞内HRP染色的方法显示该神经元位于猫运动皮层十字沟后,在第Ⅱ/Ⅲ层之间(软膜以下438μm处),胞体截面积为15.6×28.1μm~2,呈多极形,树突呈串珠状,向四周扩展,无侧棘,轴突由胞体下方伸出,返折向上,包绕胞体周围,以软膜平行的吻尾方向行走为主,有一分枝向白质方向延伸.从立体重构图的不同角度观察,其形态不对称,如沿X轴方向旋转60°后,其形态呈扁平形,用胶体金免疫电镜观察,该神经元的递质性质为GABA能的.胞体及树突上分布有非对称型和对称型的突触,对称型的突触中有的是GABA能的,有的是非GABA能的.其轴突有髓鞘包绕,末梢与其它神经元的胞体形成一处以上相连或不相连的对称型突触,也可与其它树突形成对称型的突触.根据该神经元的形态,递质性质及突触分布的特征,可确认它是篮状细胞.

A MORPHOLOGICAL STUDY ON INTRACELLULARLY LABELED BASKET CELLS OF MOTOR CORTEX IN CAT

A basket-like cell in cat motor cortex was labeled intracellularly with HRP staining method and investigated morphologically. This neuron was located in layer II-III of the postcruciate gyrus, 438um beneath the piamater. It was a multipolar cell with multiple smooth beaded dendrites, extending radially from the cell body but with no spine. Its axon arose from the base of the soma, turned upward and ramified densely in the vicinity of the soma approximately along the direction parallel to the piamater. Viewed from different angles, the three-dimensional image of the neuron was not symmetric. The cell was identified as a GABA-immunoreactive neuron using immunogold electronmicroscopic technique. Symmetrical and asymmetrical synapses were found on the soma and dendrites. The number of symmetrical synapses was more than that of asymmetrical synapses. Not all the symmetrical synapses were GABAergic. The axon was enfolded by myelin sheath and its terminals formed symmetrical synapses with soma and dendrites of other neurons at more than one site.