Cummings J F, de Lahunta A
Department of Anatomy, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
Acta Neuropathol. 1988;75(3):261-71. doi: 10.1007/BF00690534.
In a litter of three Miniature Poodles, a normal female pup contrasted with two males which displayed severe equilibrium and postural disturbances soon after birth. In the male pups diffuse cerebral cortical degeneration accompanied cerebellar cortical atrophy, which was characterized by extensive loss and degeneration of Purkinje neurons. As in some prior histological descriptions of canine cerebellar atrophies, degenerating Purkinje cells appeared either pale, swollen and vacuolated or shrunken and hyperchromatic. Swollen vacuolated cell bodies and condensed necrotic neurons were scattered through the cerebral cortex. Ultrastructural studies revealed that the vacuolar degeneration in Purkinje and cerebral neurons was referable to marked dilation of endoplasmic reticulum and loss of ribosomes. In shrunken Purkinje neurons, increased cytoplasmic eosinophilia was associated with a decline in Nissl bodies and accumulations of mitochondria and especially lamellar bodies. The latter, stacked derivatives of endoplasmic reticulum, were not encountered in shrunken cerebral perikarya. Lamellar bodies reached giant proportions in the dendritic stems of degenerating Purkinje neurons. In Purkinje axons, however, these bodies often were overshadowed by aggregates of axoplasmic tubules. The cytological changes in these Poodle pups were notably different from those reported in earlier ultrastructural studies of canine inherited cerebellar degenerations.
一窝三只迷你贵宾犬中，一只正常的雌性幼犬与两只雄性幼犬形成对比，这两只雄性幼犬在出生后不久就表现出严重的平衡和姿势障碍。雄性幼犬出现弥漫性大脑皮质变性并伴有小脑皮质萎缩，其特征是浦肯野神经元广泛丢失和变性。正如之前对犬小脑萎缩的一些组织学描述一样，变性的浦肯野细胞要么苍白、肿胀且有空泡，要么萎缩且染色质增多。肿胀有空泡的细胞体和浓缩坏死的神经元散布于大脑皮质。超微结构研究显示，浦肯野神经元和大脑神经元中的空泡变性归因于内质网的明显扩张和核糖体的丢失。在萎缩的浦肯野神经元中，细胞质嗜酸性增加与尼氏体减少以及线粒体尤其是板层小体的积聚有关。后者是内质网的堆叠衍生物，在萎缩的大脑周核中未见到。板层小体在变性的浦肯野神经元的树突干中达到巨大比例。然而，在浦肯野轴突中，这些小体常常被轴浆微管聚集体掩盖。这些贵宾犬幼犬的细胞学变化与早期犬遗传性小脑变性的超微结构研究报道的变化明显不同。
