Mohammed A K, Maehlen J, Magnusson O, Fonnum F, Kristensson K
Department of Geriatric Medicine, Huddinge Hospital, Sweden.
Neurobiol Aging. 1992 Jan-Feb;13(1):83-7. doi: 10.1016/0197-4580(92)90013-n.
Suckling rats were infected intranasally with the temperature-sensitive mutant G41 strain of vesicular stomatitis virus. The rats survived but demonstrated lifelong learning deficits in the Morris maze and impaired exploratory behaviour in the open field test. When examined at 18 months of age they had a severe loss of neurons in the medial and dorsal raphe nuclei in the brain stem and reduced levels of serotonin and its metabolite 5-hydroxyindole acetic acid in the cerebral neocortex and hippocampus. The levels of noradrenaline, dopamine, homovanillic acid, 3,4-dihydroxyphenylacetic acid, choline acetyltransferase and glutamate decarboxylase were largely unaffected. The permanent disturbance in brain serotonin metabolism did not cause any histological changes in the cerebral cortex. Thus there were no neurofibrillary tangles or amyloid plaques as has been reported as a late effect of chemically induced lesion to the cholinergic system in the rat brain. It is concluded that the brain serotonergic system is especially vulnerable to an episode of virus attack along olfactory pathways and that the neurochemical and behavioural alterations caused by such an episode persist during a major part of the animal's life span.
将乳鼠经鼻内接种水疱性口炎病毒的温度敏感突变株G41。这些大鼠存活了下来,但在莫里斯水迷宫中表现出终身学习缺陷,在旷场试验中探索行为受损。在18个月大时检查发现,它们脑干中缝内侧核和背侧核的神经元严重缺失,大脑新皮层和海马体中血清素及其代谢物5-羟吲哚乙酸水平降低。去甲肾上腺素、多巴胺、高香草酸、3,4-二羟基苯乙酸、胆碱乙酰转移酶和谷氨酸脱羧酶的水平基本未受影响。大脑血清素代谢的永久性紊乱并未引起大脑皮层的任何组织学变化。因此,没有出现神经原纤维缠结或淀粉样斑块,而在大鼠脑中化学诱导损伤胆碱能系统的后期效应中曾有此类报道。结论是,大脑血清素能系统特别容易受到沿嗅觉途径的病毒攻击,并且这种攻击引起的神经化学和行为改变在动物寿命的大部分时间内持续存在。