动物造模,哺乳动物 z-bo 2020-09-26 402

　　In the early days of development, two research teams in China used genetic technology to process special odors during the first week of life and locked the detailed transmission line from the nose to the brain. 

　　This sensory system belongs to the central nervous system of mammals. Like vision, neurons need to move in a specific direction and map to a specific point. Like vision, smell is the first sensory input of a signal, which is then projected to the brain. The correct area has a period called the critical period of this process. But specifically, scientists are still uncertain whether there is such a critical period in the olfactory system.

　　Recently, two Chinese research teams used genetic technology to disrupt the olfactory system of mice, express false olfactory receptors in olfactory sensor neurons (OSNs), and analyze the wrong pathways in the brain. And analyzed this process of neurotransmission. When odor molecules bind to millions of olfactory receptors in the nasal cavity of mammals, animals will discover odors. These olfactory receptors are located in the olfactory neuron (OSN). Each olfactory neuron connects its unique odor-specific receptor protein and nerve fibers, which connect the same receptor OSN to the characteristic part of the brain. And finally connect to the brain. Can form special nerve pathways.

　　Drexel University's Lulu Tsai research group published an article titled "The critical period defined by the axon targeting mechanism in the mouse olfactory bulb". Genetic technology was used to interrupt this route and calculate the time frame for the recovery of the olfactory nerve route map after the disturbance. The researchers found that turning on the wrong protein did not cause olfactory dysfunction shortly after the mice were born. This shows that the normal olfactory roadmap was formed in the early stages of development, so even if the roadmap is damaged, it can be reconstructed.

　　On the contrary, in the article of the research group of Chinese scientist C. Ron Yu of the Stokes Institute in Kansas, USA, "The developmental switch that targets axons on the olfactory system of continuously regenerating mice" showed that after turning off the wrong protein How to close the roadmap. I confused the initial development roadmap in order to understand. It has been rebuilt. The researchers found that if the protein is expressed shortly after birth, the roadmap can be restored in the right way, but if the protein is expressed 7 days after birth, the damage is permanent. All in all, the results of the two research teams show that the remodeling of the mammalian olfactory system will not last long after birth, and the olfactory roadmap has been locked. At the same time, another article in "Science" magazine detailed these two results.