Decoding the circuitry of consciousness: from local microcircuits to brain-scale networks

TL;DR

This review explores how local microcircuits and large-scale brain networks interact to produce consciousness, linking neurophysiological data with theoretical models and discussing implications for disorders of consciousness.

Contribution

It integrates micro- and macro-circuit perspectives in consciousness research, proposing cellular mechanisms that extend existing theories.

Findings

Cortico-cortical and thalamo-cortical connectivity relate to awareness and wakefulness.

GABAergic interneurons play key roles in network reorganization.

Nested oscillations facilitate neural synchronization and information processing.

Abstract

Identifying the physiological processes underlying the emergence and maintenance of consciousness is one of the most fundamental problems of neuroscience, with implications ranging from fundamental neuroscience to the treatment of patients with disorders of consciousness (DOC). One major challenge is to understand how cortical circuits at drastically different spatial scales, from local networks to brain-scale networks, operate in concert to enable consciousness, and how those processes are impaired in DOC patients. In this review, we attempt to relate available neurophysiological and clinical data with existing theoretical models of consciousness, while linking the micro- and macro-circuit levels. First, we address the relationships between awareness and wakefulness on the one hand, and cortico-cortical, and thalamo-cortical connectivity on the other hand. Second, we discuss the role of three main types of GABAergic interneurons in specific circuits responsible for the dynamical re-organization of functional networks. Third, we explore advances in the functional role of nested oscillations for neural synchronization and communication, emphasizing the importance of the balance between local (high-frequency) and distant (low-frequency) activity for efficient information processing. The clinical implications of these theoretical considerations are presented. We propose that such cellular-scale mechanisms could extend current theories of consciousness.