Columnar localization and laminar origin of cortical surface electrical potentials

xlomafota13 shared this article with you from Inoreader Columnar localization and laminar origin of cortical surface electrical potentials Via cortical auditory J Neurosci. 2022 Mar 23:JN-RM-1787-21. doi: 10.1523/JNEUROSCI.1787-21.2022. Online ahead of print. ABSTRACT Electrocorticography (ECoG) methodologically bridges basic neuroscience and understanding of human brains in health and disease. However, the localization of ECoG signals across the surface of the brain and the spatial distribution of their generating neuronal sources are poorly understood. To address this gap, we recorded from rat auditory cortex using customized μECoG, and simulated cortical surface electrical potentials with a full-scale, biophysically detailed cortical column model. Experimentally, μECoG-derived auditory representations were tonotopically organized and signals were anisotropically localized to ≤±200 μm, i.e., a single cortical column. Biophysical simulations reproduce experimental findings, and indicate that neurons in cortical layers V and VI contribute ∼85% of evoked high-gamma signal recorded at the surfa ce. Cell number and synchrony were the primary biophysical properties determining laminar contributions to evoked μECoG signals, while distance was only a minimal factor. Thus, evoked μECoG signals primarily originate from neurons in the infragranular layers of a single cortical column.Significance Statement:Electrocorticography (ECoG) methodologically bridges basic neuroscience and understanding of human brains in health and disease. However, the localization of ECoG signals across the surface of the brain and the spatial distribution of their generating neuronal sources are poorly understood. We investigated the localization and origins of sensory evoked ECoG responses. We experimentally found that ECoG responses were anisotropically localized to a cortical column. Biophysically detailed simulations revealed that neurons in layers V &VI were the primary sources of evoked ECoG responses. These results indicate that evoked ECoG high-gamma responses are primarily generat ed by the population spike rate of pyramidal neurons in layer V/VI of single cortical columns, and highlight the possibility of understanding how microscopic sources produce mesoscale signals. PMID:35332084 | DOI:10.1523/JNEUROSCI.1787-21.2022 View on the web Inoreader. Take back control of your news feed. Follow us on Twitter and Facebook.