光照射脊髓,动物实验 z-bo 2020-08-17 474

　　For the first time, neuroscientists at the Massachusetts Institute of Technology (MIT) realized the use of glazing technology to control animal muscle movements. They illuminated the spinal cord of awake mice with blue light, and the mice’s hind paws were unable to move. Researchers believe that this result provides a new method that can help people study how the complex spinal cord coordinates movement and sensory processes.

　　This research was led by Emilio Beach, a professor at the McGovern Institute for Brain Science at the Massachusetts Institute of Technology. In the past, neuroscientists used electrical stimulation or drug intervention to control the activity of neurons and understand their functions. Although these methods reveal a lot of information about the spinal cord, they still cannot precisely control specific types of neurons. This study explored the use of glazing techniques to study the function of inhibitory interneurons. These neurons form circuits with other neurons in the spinal cord to execute commands from the brain and send sensory information from the limbs to the brain. Optogenetics technology allows certain types of neurons to express light-sensitive proteins called opsins through genetic programming. Opsin is an ion channel and a "pump" that mediates the electrical activity of neurons. Exposure to light prevents the activity of certain opsins and activates the activity of other opsins. Inhibitory neurons in the spinal cord prevent muscle contraction. This is the key to maintaining balance and coordinated exercise. For example, when you put an apple in your mouth, your biceps contract and your triceps relax. Feng Guoping, a professor of neuroscience at the Massachusetts Institute of Technology, has used transgenic technology to cultivate mice, in which inhibitory spinal cord neurons can express an opsin called channel rhodopsin 2, which is activated by blue light irradiation. .. In the experiment, the mice were able to move freely, and the researchers observed the effect of irradiating various points on the spinal cord of the mice and activating neurons. When the inhibitory neurons in the thoracic spine were activated, the two legs immediately stopped moving in the mouse, indicating that the inhibition of the thoracic spine might be transmitted to the spinal cord. It has been displayed. "Mr. Kagino said. They also found that activation of inhibited neurons does not affect the transmission of sensory signals and normal neural reflexes.

　　"The use of optogenetics also raises interesting questions." For example, Simon Gist, professor of neurobiology and anatomy at Drexel University in the United States, said: "This mechanism will be a comprehensive mechanism. Will the deadly brain transition develop inhibitory neurons into modules that give people more freedom to choose how to exercise?"

　　But this study also shows the benefits of photogenomics. The MIT team hopes to continue using it. Explore other types of spinal neurons to understand how brain commands affect these spinal circuits.