A Stanford University research team has developed two new optical instruments that can observe neural activity in the brain with unprecedented clarity. Published in Cell, the study reveals three previously unknown propagation patterns of brain waves, offering fresh insights into how the brain functions.

The technology builds on the TEMPO optical method first reported in 2016 and comprises two complementary instruments: a fiber-optic sensor with 10× improved sensitivity and an optical mesoscope capable of imaging an 8mm-wide brain region. Senior author Professor Mark J. Schnitzer stated: "We can now simultaneously observe multiple brain regions and see brain waves sweeping across the cerebral cortex in a cell-type-specific manner."

Unlike traditional electroencephalography (EEG), the new technology not only images brain waves in real time but also focuses on activity in specific neuron types. The researchers discovered two types of β waves propagating at right angles and a bidirectionally propagating θ wave. Co-first author Radosław Chrapkiewicz noted: "This back-and-forth θ wave may resemble learning mechanisms in artificial intelligence, suggesting the brain has the capacity to reorganize long-range neural circuits."

Lead author Simon Haziza said the technology holds promise for advancing understanding of neurological disorders such as Parkinson's and Alzheimer's. The Schnitzer lab particularly thanked Vasily Kruzhilin for developing key analysis algorithms and Yanping Zhang for establishing the mouse models.