动物实验 z-bo 2020-08-26 564

　　The negative emotion of worrying about fear is not completely meaningless. It makes humans more vigilant and careful in dangerous situations and thus obtains a better chance of survival. It has played an important role in human evolution. However, everything is too bad, too much fear can lead to anxiety. According to statistics, 8% of Americans have suffered from post-traumatic stress disorder, and 18% of Americans have varying degrees of anxiety.

　　Want to say goodbye with scary memories? If you are a little mouse, scientists can already do it for you!

　　In a paper published in the latest "Nature-Neuroscience" journal, scientists observed under a special microscope the neuronal response to the fear stimulus in the mouse brain. The poor mouse was first stimulated by the electric shock accompanied by the high-pitched sound to have a psychological shadow, and then the scientists tried to find the neural "channel" in response to the horror recall, and the mouse whose neural channel was closed by the scientists really lost the previous horror. Memories.

　　Can the unlovable mice really help scientists find the same way to make humans forget their psychological shadows?

　　There are a series of neural pathways in the brain. Previous research results have shown that the formation of fear is through a one-way path from the auditory cortex of the brain to the lateral amygdala. Yang Yang's team from the Institute of Neuroscience, Chinese Academy of Sciences discovered a new neural pathway related to fear memory.

　　In an interview with CCTV, she said that everyone thought that this cranial nerve connection pathway did not exist, and authoritative scholars’ reviews all denied the existence of the new pathway. Nevertheless, Yang Yang started by studying the Allen Human Brain Atlas, and spent several years confirming his suspicions. This neural pathway not only exists, but also plays a key role in the extraction of fear memory.

　　Finding neural pathways is the first step, and the ultimate goal is to clear memories.

　　When animals form memories, new connections between nerve axons and dendrites will also be formed. In the experiment, Yang Yang and his colleagues observed the formation of a large number of synapses near the new pathways in the stimulated mouse brain, which further confirmed the new theory.

　　In order to ensure that the new neural pathway can be inhibited, Yang Yang and the others used two technical methods, optogenetics and chemical genetics, to reduce the activity of the pathway, and the inhibitory effect was very obvious. Yang Yang believes that the current progress is relatively smooth, but the brains of mice and humans are not exactly the same. Mice are hearing animals, while humans are visually dominant animals. The next step of research should turn to the visual animal monkey, which is similar in structure to the human brain. Anatomical results have shown that there may be a new pathway from the lateral amygdala to the visual cortex, and the effect of this new neural pathway remains to be studied.

　　Yang Yang's research results have also received international attention. KayTye, a neuroscientist from the Massachusetts Institute of Technology, believes that transcranial direct current stimulation is a good research direction. Transcranial direct-current stimulation (tDCS) delivers current to any area of the brain's surface by connecting electrodes close to the scalp, and analyzes the function of the cerebral cortex by analyzing the response caused by the current. The lateral amygdala is in the deep layer of the brain, but the auditory cortex is just on the surface. Transcranial direct current stimulation and similar research methods are likely to come in handy.