背景恐惧学习的海马环路机制研究
文献类型：学位论文
| 作者 | 唐研平 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015-05 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 徐林 |
| 关键词 | 海马 背景恐惧学习 环路 光遗传学 多通道电生理记录 |
| 其他题名 | Study in Hippocampal Circuits Mechanism Underlying Contextual Fear Learning |
| 中文摘要 | 学习是外界感觉信息在神经环路上进行传导、表征并最后整合到一起的过程。海马（hippocampus）作为学习记忆的关键脑区，可接受大量感觉信息的输入，包括背景环境信息。海马相关环路包括一些投射环路和兴奋性神经元与抑制性神经元构成的局部环路。海马参与学习的过程便是感觉信息在这些投射环路以及局部环路上传导和表征的过程。背景恐惧学习（contextual fear learning）中，海马主要负责传导和表征背景环境信息，而厌恶性刺激信息是否经过海马传导并表征，现在并不清楚。 为研究厌恶性刺激信息在海马环路上的传导和表征及意义，本课题初步建立了小鼠多通道电生理记录平台，用于胞外记录海马CA1神经元动作电位发放，同时还初步建立了小鼠的光遗传学操作平台，用于控制海马神经元活动。我们用背部冷风（air-puff）作厌恶性刺激，发现air-puff能引起海马CA1神经元动作电位发放的改变；通过光电极我们甄别到，air-puff的感觉信息输入到海马CA1兴奋了锥体神经元；接着，我们用足底电击（footshock）作为厌恶性刺激，在给footshock的同时用光遗传学抑制海马CA1锥体神经元的活动，发现促进了背景恐惧学习。左右海马CA1之间存在着投射环路，但其功能不清楚，我们利用光电极兴奋一侧CA1并双侧同时记录，发现一侧CA1的兴奋抑制另外一侧的活动。 我的实验结果表明厌恶性刺激的信息确实会输入到海马，兴奋海马CA1的锥体神经元，而这种输入将会抑制背景恐惧学习过程；同时双侧海马CA1之间存在相互抑制作用，猜测海马可能通过这种相互抑制作用，抑制厌恶性刺激信息输入到CA1，从而促进背景恐惧学习。 |
| 英文摘要 | Learning is a process that diverse sensory information are conducted, represented and ultimately integrated with each other through the neural circuits. As the key brain region of learning and memory, hippocampus receives a number of sensory inputs including contextual information. Hippocampus circuits contain some projection circuits and local circuits composed of the excitatory neurons and surrounding inhibitory neurons. So, the conduction, representation and integration of sensory information in these hippocampal circuits is the process of learning. In the contextual fear learning model, the hippocampus is mainly responsible for the conduction and representation of contextual information, it is not clear that whether the aversive stimulus information is conducted and represented by hippocampus. I established the platform of multichannel recording and optogenetics in mice for study the conduction and representation of aversive stimulus information in hippocampal circuits. We used the air-puff as aversive stimulus and found that the air-puff would cause the change of spike in hippocampal CA1. Then we used the optrode to discriminate the cells type and found that the air-puff resulted in the activation of pyramidal neurons. After that, we used the footshock as aversive stimulus and found that inhibition of the pyramidal neurons activity during delivering the footshock supported contextual fear learning. There is a circuit between the bilateral CA1, but its function remians unknown. We used the optrode for unilateral stimulation and bilateral recording, finding that the activation of unilateral CA1 induce the inhibition of contralateral CA1. My results demonstrated that the aversive stimulus information can be conducted and represented through the hippocampus, activating the pyramidal neurons of hippocampal CA1 and inhibiting the contextual fear learning. Meanwhile, the reciprocal inhibition arises from bilateral hippocampal CA1, which I speculate can be as a mechanism for inhibition of aversive stimulus in hippocampal CA1 and supporting the contextual fear learning. |
| 语种 | 中文 |
| 源URL | [http://159.226.149.26:8080/handle/152453/10093]  |
| 专题 | 昆明动物研究所_学习记忆的分子神经机制 |
| 推荐引用方式 GB/T 7714 | 唐研平. 背景恐惧学习的海马环路机制研究[D]. 北京. 中国科学院研究生院. 2015. |
入库方式： OAI收割
来源：昆明动物研究所
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