Microscopic-scale recording of brain neuronal electrical activity using a diamond quantum sensor

TL;DR

This paper introduces a novel, non-invasive method for recording neuronal electrical activity at microscopic scales using a diamond quantum sensor, enabling detailed brain circuit analysis without damaging tissue.

Contribution

It presents the first passive, biocompatible quantum sensor technique for in situ recording of neuronal signals, avoiding traditional invasive methods.

Findings

Successfully recorded action potentials in mouse brain tissue

Demonstrated pharmacological modulation with tetrodotoxin

Achieved high-resolution biomagnetic recordings of neural activity

Abstract

An important tool in the investigation of the early stages of neurodegenerative disease is the study of dissected living tissue from the brain of an animal model. Such investigations allow the physical structure of individual neurons and neural circuits to be probed alongside neuronal electrical activity, disruption of which can shed light on the mechanisms of emergence of disease. Existing techniques for recording activity rely on potentially damaging direct interaction with the sample, either mechanically as point electrical probes or via intense focused laser light combined with highly specific genetic modification and/or potentially toxic fluorescent dyes. In this work, we instead perform passive, microscopic-scale recording of electrical activity using a biocompatible quantum sensor based on colour centres in diamond. We record biomagnetic field induced by ionic currents in mouse corpus callosum axons without direct sample interaction, accurately recovering signals corresponding to action potential propagation while demonstrating in situ pharmacology during biomagnetic recording through tetrodotoxin inhibition of voltage gated sodium channels. Our results open a promising new avenue for the microscopic recording of neuronal signals, offering the prospect of high resolution imaging of electrical circuits in the living mammalian brain.