面向情感和记忆神经环路图谱的荧光标记策略研究

Psychiatric disease is attributed either to disordered circuitry or to disordered neural activity in brain circuitry. There is considerable evidence that the diverse GABAergic neurons of amygdala and related neuromodulator systems are centrally involved in emotional memory and mood disorders. A major challenge in neuroscience is to dissect how these large number and diverse types of neurons interact to construct connectivity motifs and circuit modules that underlie emotianl experience and memory. With the increasing resource of transgenic mice and genetic manipulation tools, it is now reasonable to launch a program of dissection of amygdalar emotional circuits through systematic targeting of diverse cell types and mapping of neural circuits. For this purpose, the genetic intersection strategy with Cre-loxp and Flp-Frt systems will be taken to achieve expression of genetically encoded fluorescent proteins that are conditional upon cell-type features and virus systems. Combination with Micro-Optical Sectioning Tomography system, we will be able to collect the neuronal precise 3D structure with single fiber resolution in cell-type specific way. Here, we will focus on amygdalar GABAergic neurons and several neuromodulator systems. Our results will improve understanding the mechanism of emotional memory and the etiology of psychiatric disorders.

神经环路主要由兴奋性谷氨酸能神经元和抑制性神经元组成，是大脑行使功能的结构基础。兴奋性神经元与抑制性神经元电活动平衡的异常及其神经调质介导的调制紊乱均可导致脑疾病的发生。神经环路重要的功能存在于神经调质对种类众多的抑制性神经元的行为状态依赖的调节之中。不同类型的抑制性神经元有着不同的形态、生理学特性、连接模式和基因表达谱；而且接受广泛的神经调质系统的功能调制，参与多种情感记忆的获得和精神疾病的发生发展。本项目将结合已有的丰富的Cre基因敲入小鼠资源和多种遗传重组改造的腺相关病毒AAV，利用Cre和Flp双开关依赖的重组酶控制系统，实现对多种神经调质系统如多巴胺能，5-羟色胺能，胆碱能神经元和杏仁核特定类型抑制性神经元高亮度的稀疏标记和跨突触追踪。为显微光学切片断层成像系统，提供理想的标记样本。实现上述多个神经环路大范围、高精度的图像获取，绘制情感与记忆相关神经环路的脑图谱。

情感记忆类的神经精神疾病如焦虑症,学习障碍等是困扰人类健康的巨大社会问题。这往往是大脑调控这些疾病的结构基础-神经环路发生了病变或功能异常导致的。大脑中不同类型的神经元有着不同的形态、连接模式和功能，以不同的方式参与多种情感记忆的获得和精神疾病的发生发展。本项目结合丰富的Cre基因敲入小鼠资源、多种遗传重组改造的腺相关病毒AAV、光遗传学、显微光学切片断层成像系统、多种行为范式以及活体电生理等先进的神经生物学技术，对两个分别调节焦虑症和高级认知学习相关的脑区前背侧终纹床核和中央杏仁核不同类型神经元在结构和功能上进行了全面解析。绘制了前背侧终纹床核三类与焦虑有关的神经元在全脑的输入和输出的图谱。全面剖析了参与高级认知学习-负性强化关联学习中央杏仁核-无名核神经环路和机制。为人们探究情感与记忆相关的神经精神疾病提供了重要的理论依据和建设性的指导意义。