Volumetric mesoscopic electrophysiology: a new imaging modality for the non-human primate.
bioRxiv : the preprint server for biology – May 14, 2024
Source: PubMed
Summary
Scientists have developed a groundbreaking way to observe brain activity across an entire primate hemisphere simultaneously. Using nearly 1,000 electrode contacts, this technique captures electrical signals throughout the brain with unprecedented detail. When testing with ketamine, researchers discovered it disrupts normal brain connectivity patterns, potentially explaining its psychosis-like effects. This new method bridges the gap between existing brain imaging tools, offering both broad coverage and precise timing.
Abstract
The primate brain is a densely interconnected organ whose function is best understood by recording from the entire structure in parallel, rather than parts of it in sequence. However, available methods either have limited temporal resolution (functional magnetic resonance imaging), limited spatial resolution (macroscopic electroencephalography), or a limited field of view (microscopic electrophysiology). To address this need, we developed a volumetric, mesoscopic recording approach ( MePhys ) by tessellating the volume of a monkey hemisphere with 992 electrode contacts that were distributed across 62 chronically implanted multi-electrode shafts. We showcase the scientific promise of MePhys by describing the functional interactions of local field potentials between the more than 300,000 simultaneously recorded pairs of electrodes. We find that a subanesthetic dose of ketamine -believed to mimic certain aspects of psychosis- can create a pronounced state of functional disconnection and prevent the formation of stable large-scale intrinsic states. We conclude that MePhys provides a new and fundamentally distinct window into brain function whose unique profile of strengths and weaknesses complements existing approaches in synergistic ways.