In the journal Cell, researchers funded by the National of Health described in an article how they used advanced genetic engineering techniques to transform bacterial proteins into a new research tool that can compare to existing Methods to monitor the spread of serotonin more effectively.

Preclinical experiments (mainly in mice) have shown that the sensor can detect subtle real-time changes in brain serotonin levels during sleep, fear, and social interaction, and test the effectiveness of new psychoactive drugs.

The research was partly funded by the National of Health’s Brain Research through the Advanced Innovative Neurotechnology (BRAIN) program, which aims to revolutionize our understanding of the brain under health and disease conditions.

The research was led by researchers from Dr. Lin Tian, ​​the principal investigator of the University of California Davis School of Medicine. Current methods can only detect widespread changes in serotonin signaling. In this study, the researchers converted the nutrient-rich Venus flytrap-like bacterial protein into a highly sensitive sensor that fluoresces when it captures serotonin.

Previously, scientists in Dr. Loren L. Looger’s laboratory at the Howard Hughes Medical Institute Janelia Research Park in Ashburn, Virginia used traditional genetic engineering techniques to convert bacterial proteins into sensors for the neurotransmitter acetylcholine.

This protein called OpuBC usually outlines nutrient choline, which is shaped like acetylcholine. In this study, Tian’s lab worked with Dr. Looger’s team and Dr. Viviana Gradinaru’s lab in Caltech, Pasadena, California, and showed that they needed additional help from artificial intelligence to completely redesign OpuBC. Serotonin catcher.

Researchers use machine learning algorithms to help computers “think” 250,000 new designs. After three rounds of testing, the scientists decided on one of them. Preliminary experiments have shown that this new sensor can reliably detect different levels of serotonin in the brain, while it has little response to other neurotransmitters or similarly shaped drugs.

See also  Brutal case study shows why you need to fire cotton buds to clean your ears

Experiments on mouse brain slices showed that the sensor responds to serotonin signals sent between neurons at synaptic communication points. At the same time, experiments on cells in a petri dish show that the sensor can effectively monitor the changes in these signals caused by drugs, including cocaine, MDMA (also known as ecstasy) and several commonly used antidepressants.

Finally, experiments conducted in mice show that the sensor can help scientists study serotonin neurotransmission under more natural conditions. For example, researchers have witnessed an expected increase in serotonin levels when awake, and a decrease in serotonin levels when the mice fall asleep.

When the mice finally entered a deeper REM sleep state, they also found a greater decline. Traditional serotonin monitoring methods ignore these changes. In addition, the scientists also found that when the alarm bell warns the rat’s foot tremor, the levels of serotonin are different in two independent brain fear circuits.

In one circuit-the medial forehead cortex-the bell triggers a rapid increase in serotonin levels, while in the other circuit-the basolateral amygdala-the transmitter gradually rises to a lower level.

In the spirit of the “Brain Project”, the researchers plan to provide this sensor to other scientists. They hope this will help researchers better understand the key role of serotonin in our daily and many mental illnesses.