A morphological study of the brain in the ataxic mutant rat.

一种共济失调突变大鼠，稀释性角弓反张（dop），最初是在Wister大鼠的繁殖群中发现的，表现出毛色稀释和神经系统疾病，伴惊厥性肢运动和角弓反张性癫痫发作，持续至3周龄动物死亡。这些动物是在我们的实验室中通过杂交杂合子（dop/+）大鼠来繁殖的。PCR扩增的微卫星标记将该基因定位于第8号染色体上，显示Apoc 3、dop和Mylclv基因连锁，表明该突变与小鼠的稀释致死性基因同源。5-三磷酸（InsP 3）受体抗体显示，平滑肌内质网（SER）dop小脑浦肯野细胞树突棘缺失。对发育中的浦肯野细胞的观察表明，SER形成于浦肯野细胞的索马和树突中，而不形成于浦肯野细胞的棘中，SER被认为是细胞内的钙库，并被认为突触部位的钙信号过程在突触传递中起着关键作用。因此，dop大鼠被认为突触调节受损。电镜和免疫细胞化学显示浦肯野细胞轴突终末与小脑深核神经元接触正常。

An ataxic mutant rat, dilute-opisthotonus (dop), was originally discovered in a breeding colony of Wister rats and shows a dilution of coat color and neurological disorders with convulsivelimb movements and opisthotonic seizures continuing until the death of animals at 3 weeks of age. The animals have been bred in our laboratory by intercrossing the heterozygous (dop/+) rats. The dilute-opisthotonus gene was mapped on chromosome 8 by PCR-amplified microsatellite markers, which showed a linkage of Apoc3, dop and Mylclv genes, suggesting that this mutation was homologous to dilute-lethalof the mouse.Electronmicroscopy and immunocytochemistry using anti-inositol 1,4,5-triphosphate (InsP3) receptor antibody revealed that smooth endoplasmic reticulum (SER) was missing in the dendritic spine of Purkinje cell in the dop cerebellum. Observation of developing Purkinje cells showed that SER was formed in the soma and dendrites but not in the spine of the Purkinje cell.SER is assumed to be an intracellular Ca store and it has been suggested that a Ca signaling process at the synaptic site has a key role in synaptic transmission. Thus, the dop rat is thought to have impaired synaptic regulation. Electronmicroscopy and Immunocytochemistry using antibody raised against GABA,transmitter released by Purkinje cell terminals, indicated that Purkinje cell axon terminals normally contacted the neurons in deep cerebellarnuclei.