在进化的过程中，哺乳动物新皮质的出现使其更加适应复杂多变的环境，哺乳动物神经元“由内向外”迁移形成新皮质的特有的六层结构是进化过程中至关重要的一次创新。目前人们对人类智商、情绪、认知和神经系统类疾病等的神经生物学机制并未彻底弄清。为此，对新皮质的发育和进化机制展开深入研究就显得尤为重要。此前实验室通过生物信息学的方法对脊椎动物脑皮质和皮质下区域发育过程中一些重要的基因进行比较分析后，发现与非哺乳动物相比，哺乳动物Emx1和Emx2基因编码的蛋白质序列发生了改变，目前对这两个基因的研究主要通过在鼠中敲除完成，此前实验室的研究在鸡胚端脑过表达鼠Emx2基因同时过表达鼠的Emx1和Emx2基因后，对胚胎期以及出生后和脑发育相关的重要分子（Reelin、GABA、Vimentin等）进行检测，发现这些分子的表达都有显著增强，且同时过表达两个基因后这种增强更为显著。本研究中，干扰鸡胚端脑Emx2基因的表达后，胚胎期免疫组织化学染色发现上述与脑发育相关的重要分子的表达都降低，而同时干扰Emx1基因和Emx2基因的表达后，这种降低的程度更为显著。为更进一步了解这些分子发生变化后，小鸡端脑的神经元发生模式是否会变化，我们还用Brdu标记新生的神经元细胞，同时通过免疫荧光染色标记GABA能中间神经元PV和CB，揭示干扰Emx2基因的表达后，对小鸡端脑神经元发育模式的影响。结果显示干扰Emx2基因的表达后，Wulst区PV神经元的迁移模式更加偏向于由外向内，CB神经元的迁移模式无明显改变，对于M区和N区这两种神经元的迁移模式均没有显著的影响。

In the process of evolution, the emergence of the mammalian neocex makes it more adaptable to the complicated and changeable enviroment. The mammalian brain uses an “inside-out” way to form neocortex with six layers structure. This is a crucial innovation in the process of brain evolution. It is important for human beings to understand intelligence, emotion, congtive and the mechanisms of nervous system diseases. To address this issue, our laboratory analyzed the key genes in pallium evolution through bioinfornatics methods and found that, in contrast to those in non-mammals, the protein sequences encoding Emx1 and Emx2 genes in mammals are changed. To date, the related studies on the two genes have been performed in knockout mice. In our previous studies, we tranferred the mouse Emx2 gene into the embryonic chick brains in which both Emx1 and Emx2 gene expressed in the telencephalon. Our results indicated that some genes involved in the development of pallium such as Reelin and Map2, the brain structure, the ability of memory of lerning, movement and the ability to explore new things changed significantly. In the present study, Emx2 gene was further knock-down, and we used immunohistochemistry techniques to determine which changes ocuured. We found that some genes involved in the development of pallium such as Reelin and Map2, the brain structure decreased after Emx2 gene knock-down. In order to explore if the development pattern of GABA neurons in chick embryo telencephalon will be changed, we used BrdU to label newborn cells. Then we exmained the BrdU labeled PV, CB neurons, and we wanted to determine whether these doubled cells follows inside-out or outside-in pattern during pallin development in Wulst, M and N of chick embryo telencephalon. Our results revealed that after Emx1 and Emx2 knock-down, PV neuronal migration patterns more biased towards the outside-in and there are no significant changes in migration patterns of CB neurons. In addition, PV or CB neuronal migration patterns did not changed significantly in M and N areas of chick pallium.