Doughty M L, Patterson L, Caddy K W
Department of Physiology, University College London, United Kingdom.
J Comp Neurol. 1995 Jun 19;357(1):161-79. doi: 10.1002/cne.903570114.
Lurcher is an autosomal semidominant murine mutation. Lurcher heterozygotes (+/Lc) lose all their cerebellar Purkinje cells by adulthood. Explants from 2 days postnatal (P2) wild-type (+/+) and +/Lc cerebellar cortex were grown in vitro to investigate the role of local neuronal environment and afferent input on the degenerating +/Lc Purkinje cell. In Lurcher explants, Purkinje cells were maintained for up to 25 days in vitro. No significant difference was observed between +/+ and +/Lc Purkinje cell numbers from 10 to 20 days in vitro, as revealed by calbindin-D immunoreactivity. Growing +/Lc explants in association with +/+ explants resulted in no significant difference in Purkinje cell survival (10-20 days in vitro). Image analysis of the gross morphology of calbindin-D-immunostained Purkinje cells from +/+ and +/Lc explants grown in vitro revealed a significant decrease in the total area and dendritic lengths of +/Lc Purkinje cells (15 and 20 days in vitro). The fine structure of +/Lc and +/+ Purkinje cells was examined under the electron microscope (10-25 days in vitro). No difference in ultrastructure was observed between +/Lc and +/+ Purkinje cells grown in vitro, and many features similar to normal Purkinje cell development in vivo were present. These included monosynaptic parallel fibre synapses with Purkinje cell dendritic spines, other interneuron synapses with Purkinje cell dendrites and soma, astroglial investment, and minimal extracellular space in the neuropil. Unusual features observed included a persistence of the perisomatic spines in some Purkinje cells, an absence of Nissl bodies in the Purkinje cell perikaryon, naked Purkinje cell dendritic spines, and occasional heterologous synapses. The results are discussed in the light of previous chimeric analysis of the Lurcher mutation, and a hypothesis is put forward to explain the survival of +/Lc Purkinje cells in vitro.
Lurcher是一种常染色体半显性小鼠突变。Lurcher杂合子（+/Lc）在成年时会失去所有小脑浦肯野细胞。取出生后2天（P2）的野生型（+/+）和+/Lc小鼠小脑皮质进行体外培养，以研究局部神经元环境和传入输入对+/Lc浦肯野细胞退化的作用。在Lurcher外植体中，浦肯野细胞在体外可维持长达25天。通过钙结合蛋白-D免疫反应性检测发现，在体外培养10至20天时，+/+和+/Lc浦肯野细胞数量无显著差异。将+/Lc外植体与+/+外植体联合培养，浦肯野细胞存活率无显著差异（体外培养10 - 20天）。对体外培养的+/+和+/Lc外植体中钙结合蛋白-D免疫染色的浦肯野细胞进行大体形态的图像分析，结果显示+/Lc浦肯野细胞的总面积和树突长度显著减少（体外培养15天和20天）。在电子显微镜下观察了+/Lc和+/+浦肯野细胞的精细结构（体外培养10 - 25天）。体外培养的+/Lc和+/+浦肯野细胞在超微结构上未观察到差异，且呈现出许多与体内正常浦肯野细胞发育相似的特征。这些特征包括浦肯野细胞树突棘上的单突触平行纤维突触、浦肯野细胞树突和胞体与其他中间神经元的突触、星形胶质细胞包绕以及神经毡中最小的细胞外间隙。观察到的异常特征包括一些浦肯野细胞的胞体周围棘持续存在、浦肯野细胞胞质中无尼氏体、裸露的浦肯野细胞树突棘以及偶尔的异源突触。结合之前对Lurcher突变的嵌合体分析对结果进行了讨论，并提出了一个假说来解释+/Lc浦肯野细胞在体外的存活情况。
