Task rule and choice are reflected by layer-specific processing in rodent auditory cortical microcircuits

Abstract

The primary auditory cortex (A1) is an essential node in the integrative brain network that encodes the behavioral relevance of acoustic stimuli, predictions, and auditory-guided decision making. Previous studies have revealed task-related information being present at both the single-unit and population activity. However, its realization with respect to the cortical microcircuitry is less well understood. In this study, we used chronic, laminar current source density (CSD) analysis from the A1 of behaving Mongolian gerbils (Meriones unguiculatus) in order to characterize layer-specific, spatiotemporal synaptic population activity. Animals were trained to first detect and subsequently to discriminate two pure tone frequencies in consecutive training phases in a Go/NoGo shuttle-box task. We demonstrate that not only sensory but also task-and choice-related information is represented in the mesoscopic neuronal population code distributed across cortical layers. Based on a single-trial analysis using generalized linear-mixed effect models (GLMM), we found infragranular layers to be involved in auditoryguided action initiation during tone detection. Supragranular layers, particularly, are involved in the coding of choice options during tone discrimination. Further, we found that the overall columnar synaptic network activity represents the accuracy of the opted choice. Our study thereby suggests a multiplexed representation of stimulus features in dependence of the task, action selection, and the behavioral options of the animal in preparation of correct choices. The findings expand our understanding of how individual layers contribute to the integrative circuit of the A1 in order to code task-relevant information and guide sensory-based decision making.

Audiovisual task switching rapidly modulates sound encoding in mouse auditory cortex

“…Changes in both FR and encoding efficiency were most prominent in deep layer neurons. These findings extend several previous studies reporting larger effects of attention in infragranular LFP and multi-unit activity (O'Connell et al, 2014;Zempeltzi et al, 2020). These physiological outcomes are consistent with anatomical work suggesting top-down modulatory signals arrive primarily in the supragranular and infragranular layers (Felleman and Van Essen, 1991).…”

Echolocation reverses information flow in a cortical vocalization network

“…The probabilities are mapped by the inverse logit function (sigmoid): which restricts the model predictions to the interval [0, 1]. Because of these properties, a logistic regression with GLMs is well suited to compare data (and thus, evaluate predictions of ensuing vocal-output) on a single-trial basis 76 .…”

“…the relative pre-vocal power change). This value is dimensionless and independent of sample size 76, 77 , which makes it ideal to compare effect sizes of different models (e.g. across channels and frequency bands, as in Fig.…”

“…1g ). Effect sizes were considered small when R 2 m < 0.1, medium when 0.1 <= R 2 m < 0.4, and large when R 2 m >= 0.4 76 .…”

Cross Laminar Traveling Components of Field Potentials due to Volume Conduction of Non-Traveling Neuronal Activity in Macaque Sensory Cortices

“…However, electrical events during sensory responses were much slower than dendritic spikes. While some studies found the cross-laminar propagation of CSD components during cortical sensory responses (Jellema et al, 2004), CSD profiles of sensory response in most studies had laminar sinks/sources that remained within laminae without crossing over (Lakatos et al, 2007;Fishman and Steinschneider, 2010;Szymanski et al, 2011;Godlove et al, 2014;van Kerkoerle et al, 2014;Dougherty et al, 2017;Senzai et al, 2019;Zempeltzi et al, 2020).…”