Stimulus Driven Single Unit Activity From Micro-Electrocorticography.

John Hermiz,Nicholas Rogers,Lorraine Hossain,Mehran Ganji,Shadi A Dayeh,Ezequiel M Arneodo,Eric Halgren,Nasim Vahidi,Vikash Gilja,Timothy Q Gentner

doi:10.3389/fnins.2020.00055

Abstract

High-fidelity measurements of neural activity can enable advancements in our understanding of the neural basis of complex behaviors such as speech, audition, and language, and are critical for developing neural prostheses that address impairments to these abilities due to disease or injury. We develop a novel high resolution, thin-film micro-electrocorticography (micro-ECoG) array that enables high-fidelity surface measurements of neural activity from songbirds, a well-established animal model for studying speech behavior. With this device, we provide the first demonstration of sensory-evoked modulation of surface-recorded single unit responses. We establish that single unit activity is consistently sensed from micro-ECoG electrodes over the surface of sensorimotor nucleus HVC (used as a proper name) in anesthetized European starlings, and validate responses with correlated firing in single units recorded simultaneously at surface and depth. The results establish a platform for high-fidelity recording from the surface of subcortical structures that will accelerate neurophysiological studies, and development of novel electrode arrays and neural prostheses.

Highlights

Songbirds (Oscines) are a critical animal model for studying the neural basis of speech and auditory process, as their songs share many common features with human speech and language (Brainard and Doupe, 2002; Nottebohm, 2005; Bolhuis and Gahr, 2006; Pfenning et al, 2014)
To validate that we are sensing single unit activity (SUA) from the surface of HVC, we present subjects with potent auditory stimuli, namely the bird’s-ownsong (BOS) which is known to evoke strong responses in many HVC neurons (George et al, 2005a,b), while recording simultaneously from laminar penetrating electrode arrays (PEA) implanted in HVC below the micro-ECoG array (Figures 1B,C)
Surfacerecorded SUAs are shown to be correlated with depth-recorded SUAs; Surface-recorded SUAs are consistently modulated by the presence of auditory stimulus in a manner that is similar to that of depth-recorded SUAs

Summary

Introduction

Songbirds (Oscines) are a critical animal model for studying the neural basis of speech and auditory process, as their songs share many common features with human speech and language (Brainard and Doupe, 2002; Nottebohm, 2005; Bolhuis and Gahr, 2006; Pfenning et al, 2014). Advances in our understanding of how neural circuits give rise to these complex vocal behaviors are enabled by high-resolution and high-fidelity observations of neural activity. Such views of neural activity can enable brain-machine interface studies in songbird, providing a path for rapid development and validation of cortically driven speech prosthesis prototypes for individuals with speech and motor impairments.

Methods

Results

Conclusion