Researchers from Stanford University and Harvard Medical School have achieved a remarkable milestone in neuroscience with the development of ultra-flexible mesh neural probes. These tiny probes can be precisely implanted into sub-100-micrometer-scale blood vessels in the brains of rodents, offering a revolutionary approach to brain research.

Published in the journal Science under the title “Ultraflexible endovascular probes for brain recording through micrometer-scale vasculature,” the researchers detail their groundbreaking device’s potential. Unlike traditional methods requiring open-skull surgery, this cutting-edge technology measures field potentials and single-unit spikes in the cortex and olfactory bulb of rats without causing any brain or vasculature damage. A Perspective piece in the same journal issue highlights the significance of the team’s work.

The key to this groundbreaking technology lies in the use of ultra-flexible endovascular probes, enabling precise implantation without invasive surgery. These micro-endovascular (MEV) probes are made from polymer-based materials and can be injected into tiny blood vessels using flexible microcatheters. A saline flow carries the probe into deeper vasculature, and once in place, the microcatheter is retracted, leaving the MEV probes intact.

Compared to traditional intracranial depth electrodes, which require invasive surgery and may damage neural networks, the MEV probes exhibit long-term stability and minimal immune response during histology testing. They neither deform nor penetrate vessel walls, preserving the blood-brain barrier and maintaining blood flow and neurologic functions.

In in vivo electrophysiology recording, the researchers successfully recorded brain activity in the cortex and olfactory bulb of anesthetized rats. The probes demonstrated selective implantation and operation, providing valuable insights into neurological disease models. Moreover, single-unit activity recording achieved single-cell resolution across vessel walls.

The potential applications of this technology are vast. The cerebrovasculature includes both large superficial cortical vessels and microvasculature within the cortex. The current MEV probes can target vessels with a diameter larger than 100 μm, representing approximately 5% of rat brain vessels. By reducing the size and bending stiffness of the probes, researchers hope to target even smaller diameter vessels.

This groundbreaking platform technology offers a new frontier for research and treatment of neurological diseases. As a research tool, it holds promise for understanding brain function and diseases. Additionally, the study’s authors believe it could serve as the foundation for translating these minimally invasive neuroelectronic interfaces into clinical applications in the future.

By Impact Lab