Researchers Propose Roadmap for Brain-Wide Lifetime Electrophysiology in Mammalian Models

Understanding the brain requires tools that can follow neural activity across many scales: from millisecond electrical spikes in individual neurons to brain-wide circuit dynamics that change over months, years, and even a lifetime.

However, existing technologies still face major limitations in achieving long-term, brain-wide recording at single-cell and single-spike resolution in mammals.

A research team from Harvard University reviewed recent progress in implantable microelectronics and proposed a technological roadmap toward brain-wide lifetime electrophysiology in mammals. The review was published in Nano Research on July 14, 2026.

The team highlights that mammalian brain activity is highly dynamic across life stages. During development, neural activity helps regulate processes such as cell proliferation, migration, synapse formation, and circuit refinement. In adulthood and aging, neural activity supports learning, memory, and behavior, while abnormal activity is closely related to neurological and psychiatric disorders.

"An ideal electrophysiological technology would allow researchers to record from the mammalian brain across the whole brain and across the lifetime, while still resolving individual neurons and individual spikes," said Hao Sheng, first author of the review. "Implantable microelectronics provide one of the most promising paths toward this goal, but several engineering challenges still need to be solved."

The review organizes these challenges into several major categories. First, devices must adapt to large changes in brain size and shape, especially during development. Second, they must reduce tissue responses such as gliosis, which can degrade signal quality over time. Third, they must maintain stable electrical performance in biofluids for long-term implantation. Finally, future systems must handle large-scale data acquisition, transmission, and processing.

The review compares passive and active electrode architectures. Passive electrodes can be made ultra-thin, soft, and stretchable, making them attractive for long-term and developmental studies. Active electrodes, by contrast, integrate local amplification and multiplexing, enabling higher channel counts and improved signal quality, but they also introduce challenges related to stiffness, power consumption, and encapsulation stability.

The authors also discuss emerging strategies in materials, device architecture, implantation, wireless transmission, spike sorting, and closed-loop processing. Together, these advances may support future neural interfaces capable of tracking single-neuron activity across distributed brain regions throughout life.

The review was authored by Hao Sheng, Paul Le Floch, Thomas S. Blum, and Jia Liu from the John A. Paulson School of Engineering and Applied Sciences, Harvard University, under the supervision of Jia Liu.