Increase in AMPA receptors in aged memory-impaired rats is not associated with increase in monoamine oxidase B levels
Increase in AMPA receptors in aged memory-impaired rats is not associated with increase in monoamine oxidase B levels
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DOI：
10.1016/s0306-4522(00)00459-0
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发表时间：
2000-01-01
期刊：
影响因子：
3.3
通讯作者：
Mahy, N
中科院分区：
文献类型：
--
作者：
Andrés, N;Rodríguez, MJ;Mahy, N
根据老年大鼠在Morris水迷宫任务中的表现，可将其行为分类为认知受损或未受损。在老年Long-Evans大鼠中，功能缺陷的出现与大多数海马子区域中α-氨基-3-羟基-5-甲基-4-异恶唑丙酸（AMPA）受体亚型的增加有关，而在其他脑结构中未观察到。由于星形胶质细胞中表达的AMPA受体可能参与了延迟和长期的胶质细胞对损伤的反应，我们研究了星形胶质细胞是否参与了这些老年大鼠中观察到的AMPA受体的增加。为此，使用[H-3]拉扎贝胺，通过定量放射自显影术表征了年轻成年（6个月）和老年（24-25个月）大鼠海马和隔中用作星形胶质细胞标记物的单胺氧化酶B的分布。通过光密度法计算与年轻、老年未受损和老年受损动物脑切片的特异性结合。与年轻动物相比，老年未受损组的所有海马子区域均显示出显著的年龄相关性标记增加，而老年受损组中不存在。这与最后一组中描述的胶质细胞转录增加形成对比。我们认为老年记忆障碍动物AMPA受体的增加可能与脑星形胶质细胞的反应性有关。(C)2000 IBRO。由Elsevier Science Ltd.出版，版权所有。
Aged rats may be behaviorally classified as either cognitively impaired or unimpaired based upon their performance in the Morris water maze task. In aged Long-Evans rats, emergence of functional deficits has been related to the increase in the alpha -amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor subtype in most hippocampal subfields, not observed in other brain structures. As AMPA receptors expressed in astrocytes may participate in the delayed and long-term glial response to injury, we investigated whether astrocytes participate in the increase of AMPA receptor observed in these aged rats. To this end, distribution of monoamine oxidase B, used as an astroglial marker, was characterized by quantitative autoradiography in the hippocampus and septum of young adults (six months) and aged (24-25 months) rats using [H-3]lazabemide. Specific binding to brain sections of young, aged unimpaired, and aged impaired animals were calculated densitometrically, Compared to young animals, all hippocampal subfields in the aged unimpaired group showed a significant age-related increased labeling, which was not present in the aged impaired group. This contrasts with the increased glial transcription described in this last group. We propose that increase in AMPA receptors in the aged memory-impaired animals may be related to an atypic astrocytic reactivity. (C) 2000 IBRO. Published by Elsevier Science Ltd. All rights reserved.