Lack of cyclin D2 impairing adult brain neurogenesis alters hippocampal-dependent behavioral tasks without reducing learning ability
Lack of cyclin D2 impairing adult brain neurogenesis alters hippocampal-dependent behavioral tasks without reducing learning ability
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DOI：
10.1016/j.bbr.2011.11.007
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发表时间：
2012-02-01
影响因子：
2.7
通讯作者：
Filipkowski, Robert K.
中科院分区：
文献类型：
--
作者：
Jedynak, Paulina;Jaholkowski, Piotr;Filipkowski, Robert K.
成人脑神经发生的确切功能仍然难以捉摸，尽管它已被认为在学习和记忆过程中发挥作用。在我们的研究中，我们采用细胞周期蛋白D2基因敲除（cD2 KO）小鼠表现出受损的神经发生以及海马大小减少。然而，无论cD2基因敲除小鼠的遗传背景如何，这种表型既不会导致海马依赖性学习能力的缺陷，也不会导致记忆形成。在本研究中，对cD2 KO小鼠和对照同窝小鼠进行了具有很少或没有学习成分的依赖于大脑的行为测试。基因敲除的小鼠表现出明显的物种典型行为障碍，如筑巢、挖掘和埋大理石。与对照组小鼠相比，它们没有筑巢或筑巢质量较差，挖得不那么结实，埋的弹珠也更少。这种损伤先前已经描述过，例如，海马损伤的动物。此外，cD2 KO动物在旷场和自动运动室中也更活跃，并在IntelliCage中表现出更多的探索行为。先前在脊髓损伤动物中观察到运动性和探索行为增加。最后，cD2 KO小鼠显示出正常的蔗糖偏好，但是从第二次暴露于甜味溶液开始，而对照动物立即显示出强烈的偏好。目前的结果表明，无论是海马结构的形态异常或成年脑神经发生障碍（或两者）改变海马依赖的行为的突变小鼠不影响学习能力。这些结果也可能表明，成年人的大脑神经发生参与物种典型的行为。(C)2011爱思唯尔有限公司版权所有。
The exact function of the adult brain neurogenesis remains elusive, although it has been suggested to play a role in learning and memory processes. In our studies, we employed cyclin D2 gene knockout (cD2 KO) mice showing impaired neurogenesis as well as decreased hippocampal size. However, irrespectively of the genetic background of cD2 KO mice, this phenotype resulted in neither deficits in the hippocampal-dependent learning ability nor the memory formation. In the present study, cD2 KO mice and control littermates were subjected to hippocampal-dependent behavioral tests with little or no learning component. The knockout mice showed significant impairment in such species-typical behaviors as nest construction, digging, and marble burying. They were building none or poorer nests, digging less robustly, and burying fewer marbles than control mice. Such impairments were previously described, e.g., in animals with hippocampal lesions. Moreover, cD2 KO animals were also more active in the open field and automated motility chamber as well as showed increased explorative behavior in IntelliCage. Both increased motility and explorative behaviors were previously observed in hippocampally lesioned animals. Finally, cD2 KO mice showed normal sucrose preference, however starting from the second exposure to the sweetened solution, while control animals displayed a strong preference immediately. Presented results suggest that either morphological abnormalities of the hippocampal formation or adult brain neurogenesis impairment (or both) alter hippocampal-dependent behaviors of mutant mice without influencing learning abilities. These results may also suggest that adult brain neurogenesis is involved in species-typical behaviors. (C) 2011 Elsevier B.V. All rights reserved.