The New Silicon Chip can Record a Large Amount of Brain Activity

A Harvard University team has developed an innovative silicon chip that can record subtle changes in synaptic signals between a large number of neurons. Using this chip, the team drew and recorded over 70000 synaptic connections between 2000 rat neurons. The research results were published in the latest journal Nature Biomedical Engineering, marking a major breakthrough in neuronal recording technology and helping people gain a deeper understanding of brain function.

Advanced brain function originates from specific connections between brain cells or neurons. The contact points between neurons are called synapses, and scientists are dedicated to mapping these synaptic connections not only to reveal which neurons are interconnected, but also to evaluate the strength of each connection. Electron microscopes are a powerful tool in generating images of synaptic connections, but they cannot provide information about the strength of the connections, which limits our understanding of neural network function.

In contrast, patch clamp electrodes are currently the gold standard for recording neuronal activity. They can efficiently enter the interior of individual neurons, accurately record their synaptic signals, and judge the strength of synaptic connections based on this. However, applying this technology to the study of large-scale neuronal populations has always faced challenges.

In this study, the team used a silicon chip with a 4096 microporous electrode array to perform large-scale parallel intracellular recording in rat neurons cultured on the chip. Through this method, they extracted data from over 70000 synaptic connections from approximately 2000 neurons.

The team achieved efficient intracellular recording by injecting a small current into the electrodes to slightly open the cells. Micro porous design is similar to traditional patch clamp electrodes, but is easier to manufacture than vertical nanoneedle electrodes and has better coupling effects with the interior of neurons. The experimental results exceeded expectations, with an average of over 3600 (or 90%) out of 4096 microporous electrodes achieving intracellular coupling with top neurons. The high-quality recorded data obtained from this enables scientists to classify based on the characteristics and strength of each synaptic connection, which will greatly advance people’s understanding of neural network structure and function.

The birth of new tools will always drive a cognitive revolution, and new observational methods are also expanding our cognitive boundaries of the brain. This time, the new electronic chip developed by the research team successfully recorded the subtle changes in synaptic signals between neurons in the rat brain cell network. This chip, covered with over 4000 microporous electrode arrays on its surface, acts as a “stethoscope” between cells, recording the communication between neurons. With this technology, we not only obtained a ‘brain map’, but also saw the ‘traffic flow’ on different roads. This allows us to further understand the structure and function of neural networks, and also opens up new perspectives for treating brain diseases.