小鼠实验,大脑生物钟基因 z-bo 2020-11-05 357

　　No amount of care, no matter how soft pillows, and no matter how comfortable the photon bath, will not allow the local tyrants who travel the world to escape the torture of jet lag.

　　However, a recent study claims that scientists have found a powerful and effective way to solve this problem: They discovered a drug that can modify the dominant gene of the sleep cycle to help these haggard travelers adjust their jet lag. Not only that, all sleep problems may be resolved.

　　Every cell in the body has a special "biological clock", that is, a rich protein whose level can rise or fall rhythmically over time, which is responsible for establishing the circulatory rhythm and maintaining the synchronization of the body's cells. Located in the suprachiasmatic nucleus of the hypothalamus of the brain. The suprachiasmatic nucleus (SCN) is a small, compact area in the hypothalamus of the brain that contains more than 20,000 neuronal cells.

　　Scientists at the Salk Institute for Biology (an independent non-profit scientific research institution located in La Jolla, Southern California, and one of the most productive and high-quality research institutions in the United States in the field of life sciences) have confirmed that a type called Lhx1 Genes, this gene controls the area of our brain that is equivalent to the master clock; it controls the rhythm of the brain's day and night cycles and controls the photoreceptors to make us feel organized every day. Under normal circumstances, the brain cells controlled by Lhx1 are active synchronously, which makes them highly resistant to changes in the light source. The reason why day and night mutations can cause jet lag is the rigidity of this cell.

　　Lhx1 is less and more adaptable

　　The researchers found that the cells lacked the Lhx1 gene in animals with poor synchronization, so they tested the performance of Lhx1 in jet lag on mice (these mice do not actually travel, the researchers just They staggered their day and night cycles for 8 hours), and compared the expression of thousands of genes in other mouse SCNs. Finally, they found that 213 genes are more specific to SCN. After further screening, the researchers finally found Only one gene (namely Lhx1) is inhibited in response to light. They found that mice with less Lhx1 in their bodies adapted to the environment faster, and their neurons were less synchronized, which allowed them to adapt to new schedules faster.

　　Sleep problems can be effectively solved

　　This study provides new research ideas for researchers to develop cell regeneration therapies to restore SCN function and improve sleep disorders. At present, researchers have compiled relevant gene expression data, and they will continue to study to reveal SCN and other tissues. The expression effect of genes that control the circadian clock.

　　Finding a drug that can reduce the content of Lhx1 or the hormone controlled by Lhx1 is undoubtedly a huge improvement for drug manufacturers, which means that all sleep problems can be properly resolved. Some studies have shown that sleep cycle problems can lead to obesity, mental illness, and various other diseases. Therefore, some doctors do not recommend drugs for jet lag and shift sickness, and the previous attempts on wake-up pills are not as good as coffee. Because it works. So far, these things may be addictive or potentially fatal.

　　The human biological clock cycle is 24 hours and 18 minutes

　　The human body clock is not synchronized with the clock. Japanese scientists have published research papers saying that they found that the cycle of the human body clock is 24 hours and 18 minutes. The circadian clocks of other animals and plants have a more obvious gap with the clock. The circadian clock cycle of some animals is 23 to 26 hours, while that of plants is 22 to 28 hours.

　　The researcher also used a computer to do an experiment to simulate the evolution of the biological clock. Experiments have shown that the circadian clock cycles that are most beneficial to competition are indeed close to 24 hours, but not particularly close. Take the bird as an example. If it strictly follows the clock, when it wakes up every morning to look for food, it will find that the insects on the tree have been eaten by the first bird that flew into the forest.

　　There are multiple clocks in the brain

　　Light and sound travel at different speeds. When someone speaks, visual input and sound input will reach our eyes and ears at different times. Then such signals are processed in the brain at different rates. Nevertheless, we can feel all of this happening in real time.

　　However, when the 67-year-old PH started to experience a life of unsynchronized sound and picture after the operation. PH recalled: "I told my daughter, you have to deal with those two TV sets," then PH realized that he had heard his own voice before his jaw had moved. A scan of his brain showed that there were two injuries in the brain area that plays an important role in hearing, timing and movement.

　　In order to find out the specific reasons, Elliott Freeman of London City University and his colleagues conducted a chronological judgment test. PH was shown a series of video clips of people talking, and was asked which scenes the sound appeared before or after the lips movement. In order for him to feel the sound and picture synchronized, the researcher must play the sound 200 milliseconds before the lips move.

　　Freeman said that this implies that the same time in the external world is sensed by different parts of the brain and occurs at different times. There are actually many clocks in the brain—two clocks appeared in this experiment. In the case of PH, at least one clock was severely slowed down by these brain injuries. The time difference in PH can be very large, and it occurs so obvious that it cannot be ignored. He may only perceive one of the clocks because it is the only one that he consciously perceives.