Scientists Develop Advanced Electrodes to Unlock Secrets of Neuronal Activity During Hibernation

A team of Chinese scientists has developed a nanocomposite-modified microelectrode array (MEA) that enables long-term, high-sensitivity monitoring of neuronal activity during hibernation—revealing how certain brain cells sustain life under extremely low metabolic states. The study could pave the way for medical advances in treating stroke and metabolic disorders, as well as innovative solutions for long-duration space travel.

The study, published in ACS Sensors, was led by Prof. CAI Xinxia from the Aerospace Information Research Institute (AIR) of the Chinese Academy of Sciences, in collaboration with the China Astronaut Research and Training Center. By modifying MEAs with platinum nanoparticles (PtNPs) and Prussian blue (PB), the researchers enhanced the electrodes' ability to capture faint neural signals while reducing inflammation and improving stability over extended monitoring periods.

"Studying how neurons function in near-dormant states offers exciting opportunities for medicine and space exploration," said Prof. CAI. "Our nanocomposite-modified microelectrode design allows us to detect neuronal signals that were previously too weak to capture reliably."

The improved electrodes achieved a signal-to-noise ratio of 15.53 ± 6.73—more than three times higher than traditional MEAs—allowing scientists to record even the faintest discharges of individual neurons. In vitro stability tests showed that the electrodes maintained reliable performance for up to three months, while in vivo experiments enabled chronic neural monitoring during natural hibernation bouts in Siberian chipmunks.

The results revealed three distinct types of neurons, each showing unique response patterns during hibernation. Notably, Type 3 neurons remained active even under extremely low metabolic conditions, helping chipmunks maintain deep hibernation without brain damage. The researchers also observed a sharp increase in the theta frequency band of local field potentials during arousal, which marked the restoration of consciousness and served as a reliable predictor of arousal. 

The introduction of Prussian blue in the nanocomposite not only enhanced detection sensitivity but also mitigated the effects of reactive oxygen species. This reduced inflammation and improved recording quality, ensuring reliable long-term performance. "This technology gives us a powerful new tool for uncovering how the brain protects itself in extreme states," said a member of the research team. "It could inspire therapies for neurological diseases where energy metabolism is disrupted."

To validate the neuronal signals, the team employed ion channel protein techniques and combined them with transcriptome analysis, which revealed changes in the expression of genes such as ATP7A, KCNH8, and TMEM175 that are linked to neuronal activity during hibernation.

By advancing both microelectrode array technology and fundamental knowledge of brain function during hibernation, the study lays important groundwork for biomedical research and potential applications in human health and space medicine.