Kimberlin R H, Walker C A
J R Soc Med. 1982 Aug;75(8):618-24. doi: 10.1177/014107688207500809.
The dynamics of agent replication were studied at 8 levels of spinal cord and in 9 areas of brain of mice infected intraperitoneally with the 139A strain of scrapie agent. Replication in the CNS was first detectable at 2 levels of spinal cord between thoracic vertebrae 4 and 9. The onset of replication was progressively delayed by up to 4 weeks at increasingly lower levels of spinal cord. A similar trend was seen at higher levels of spinal cord and in brain. In brain, agent replication occurred first in medulla, then in the pons and midbrain, thalamus and hypothalamus and, finally, striatum, septum, hippocampus and cerebral cortex. These results are highly suggestive of spread of infection from peripheral sites of agent replication along autonomic fibres to midthoracic cord, followed by an ascending and descending spread of agent at an apparent rate of 0.5 to 1.0 mm/day until the whole CNS is infected. However, experiments involving sympathectomy gave inconclusive results and the evidence for neural spread of scrapie in the peripheral nervous system is circumstantial.
用139A株羊瘙痒病病原体经腹腔感染小鼠，研究了病原体在小鼠脊髓的8个节段和脑的9个区域中的复制动态。在中枢神经系统中，最早在胸4至胸9之间的2个脊髓节段检测到复制。随着脊髓节段越来越低，复制开始时间逐渐延迟多达4周。在脊髓较高节段和脑中也观察到类似趋势。在脑中，病原体复制首先发生在延髓，然后是脑桥和中脑、丘脑和下丘脑，最后是纹状体、隔区、海马和大脑皮层。这些结果强烈提示，病原体从外周复制部位沿自主神经纤维传播至胸中段脊髓，随后病原体以每天0.5至1.0毫米的明显速度进行上行和下行传播，直至整个中枢神经系统被感染。然而，涉及交感神经切除术的实验结果尚无定论，羊瘙痒病在外周神经系统中经神经传播的证据也只是间接的。
