Immunohistochemical estimation of brain choline acetyltransferase and somatostatin related to the impairment of avoidance learning induced by thiamine deficiency
Immunohistochemical estimation of brain choline acetyltransferase and somatostatin related to the impairment of avoidance learning induced by thiamine deficiency
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DOI：
10.1016/s0361-9230(00)00248-3
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发表时间：
2000-06-01
影响因子：
3.8
通讯作者：
Kisara, K
中科院分区：
文献类型：
--
作者：
Nakagawasai, O;Tadano, T;Kisara, K
我们发现硫胺素缺乏(TD)大鼠在被动回避任务后第25天表现出明显的回避学习障碍。毒扁豆碱(0.1 mg/kg，ip)TD饮食从第14天开始改善回避学习障碍，第25天恢复到配对喂养(PF)对照水平。而毒扁豆碱在第21天开始治疗的第25天未见恢复效果。为探讨TD诱导的回避学习障碍与大鼠脑内胆碱能神经元功能的关系，用二维显微分光光度法检测了大鼠脑内胆碱乙酰转移酶(ChAT)的免疫组织化学分布。大脑皮层和海马区ChAT荧光强度从第14天开始下降，第25天大脑皮层、海马区和丘脑的ChAT荧光强度与PF对照组相比明显降低。在TD饲养的第14天，生长抑素(SST)的荧光强度没有变化，但在第25天，与PF对照组相比，SST显著降低。此外，毒扁豆碱从TD饲料开始后第14天开始处理，到第25天时将SST荧光强度恢复到对照水平。这些结果提示，TD引起的回避学习障碍可能不仅涉及胆碱能系统，还可能涉及生长抑素能系统。(C)2000年爱思唯尔科学公司。
We have found that thiamine-deficient (TD) rats show significant impairment of avoidance learning on the 25th day after the start of TD diet, as measured by passive- avoidance task. Administration of physostigmine (0.1 mg/kg, i.p.) from the 14th day after the start of TD diet improved the impairment of avoidance learning to the pair-fed (PF) control level by the 25th day. However, the recovery effect of physostigmine did not occur on the 25th day when the treatment was begun on the 21st day. To ascertain the correlation between the cholinergic neuronal function in rat brain and the avoidance learning impairment induced by TD, the immunohistochemical distribution of brain choline acetyltransferase (ChAT) was determined by fluorescence intensity using two-dimensional microphotometry. The intensity of the ChAT fluorescence started to decrease in the cortex and hippocampus on the 14th day and showed a marked decrease in the cortex, hippocampus and thalamus on the 25th day of TD feeding in comparison with PF controls. The intensity of the somatostatin (SST) fluorescence was unchanged on the 14th day of TD feeding, but on the 25th day, SST was significantly decreased in comparison with PF controls. Furthermore, physostigmine treatment from 14th day after the start of TD diet reversed SST fluorescence intensity to the control level by the 25th day. These results suggest that the impairment of avoidance learning induced by TD may involve not only cholinergic but also somatostatinergic systems. (C) 2000 Elsevier Science Inc.