Researchers at the Institute of Process Engineering of the Chinese Academy of Sciences have developed a new method to monitor inhibitory neural signals in brain tissue dynamically. This approach is called Liquid/Liquid Interfacial Ultramicro Iontronics (L/L UIs).
Dynamically monitoring cerebral chloride (Cl–) in the brain is considered a challenging task. To overcome this limitation, researchers eyed tracking Cerebral Chloride, a key substance in neural inhibition.
However, under physiological conditions, Cl– is a non-electrochemically active substance and cannot easily undergo redox reactions based on electron transfer. Therefore, researchers deemed it as a non-suitable substance for monitoring inhibitory neural signals.
Unlike conventional methods that use electrons, L/L UIs use ions as signal carriers. This method uses an ultra-micropipette with an organogel-filled tip, which forms a liquid-liquid interface with brain tissues. Researchers modified this liquid-liquid surface with a series of bis-thiourea ionophores to craft ultramicro iontronics that can track Cl– under physiological conditions.
After implanting, it detects electrical signals when Cl– undergoes an ion transfer reaction at the interface.
“Unlike conventional electronics that use electrons as signal carriers, iontronics use ions as signal carriers, which represents a novel human-machine interface,” says Professor BAI Shuo.
This study, published in Science Advances, used L/L UIs in the brains of an Alzheimer’s mouse and epilepsy rat model. It was implanted in specific regions of the brain to monitor Cl– concentration differences in different parts of the brain.
A detailed map of a critical region of the developing mouse brain
The L/L UIs on the rodent’s brain demonstrated high sensitivity, excellent anti-interference, and almost real-time dynamic tracking of cerebral chloride. This dynamic tracking also showed the crucial role of potassium-chloride cotransporter 2 (KCC2) in the neuroinhibitory process.
“This work is highly relevant to the field of neuroscience and has potential diagnostic and therapeutic implications for neurodegenerative diseases such as Alzheimer’s disease and epilepsy,” says the peer reviewer at Science Advances.
“It provides new ideas for tracking non-electrochemically active ions and monitoring inhibitory neural signaling in brain tissue.“
Journal Reference
- Gu, C., Kong, F., Liang, S., Zhao, X., Kong, B., Jiang, T., Yu, J., Li, Q., Lin, Y., Bai, S., Shao, Y. (2024). In vivo dynamic tracking of cerebral chloride regulation using molecularly tailored liquid/liquid interfacial ultramicro iontronics. Science Advances. DOI: 10.1126/sciadv.adr7218
