# Breakdown of thalamocortical connectivity under sleep deprivation: implications for cognitive arousal and transient sleep states

## TL;DR

This study shows how sleep deprivation disrupts brain connections involving the thalamus, leading to cognitive fatigue and unstable wakefulness.

## Contribution

The study identifies the thalamus as a central hub for connectivity changes during sleep deprivation and links these to cognitive decline.

## Key findings

- Thalamocortical connectivity decreases in sensorimotor, visual, and limbic networks during sleep deprivation.
- Reduced thalamic self-inhibition is linked to wake-state instability and attentional lapses.
- Connectivity disruptions resemble transient sleep-like states during prolonged wakefulness.

## Abstract

Functional neuroimaging conducted at regular intervals throughout sleep deprivation reveals key thalamocortical connectivity changes that characterize the transition from a well-rested to a sleep-deprived state. Decreased thalamic connectivity is distributed across sensorimotor, visual, and limbic networks, including subcortical structures such as the parahippocampal gyrus and hippocampus. Associated changes in globally efficiency closely track group-level deficits in psychomotor vigilance, suggesting that thalamic-cortical interactions play a role in wake maintenance during sleep deprivation. These patterns of connectivity disruptions may reflect transient, sleep-like states arising from unstable wakefulness. Causal modeling indicates impaired self-inhibition within the thalamus is a dominant feature of sleep deprivation, which likely contributes to wake-state instability and attentional lapses.

Statement of SignificanceThis study provides novel insights into the impact of sleep deprivation on thalamocortical connectivity, highlighting the thalamus as a central hub for changes in functional network topology under conditions of prolonged wakefulness. Decreases in thalamocortical connectivity poses important considerations for understanding the consequence of sleep-deprived cognitive fatigue and draws parallels to potential transient sleep states. These findings contribute to our understanding of individual variability in vulnerability to sleep deprivation and underscore the thalamus as a critical target for interventions aimed at mitigating cognitive decline during sleep deprivation.

This study provides novel insights into the impact of sleep deprivation on thalamocortical connectivity, highlighting the thalamus as a central hub for changes in functional network topology under conditions of prolonged wakefulness. Decreases in thalamocortical connectivity poses important considerations for understanding the consequence of sleep-deprived cognitive fatigue and draws parallels to potential transient sleep states. These findings contribute to our understanding of individual variability in vulnerability to sleep deprivation and underscore the thalamus as a critical target for interventions aimed at mitigating cognitive decline during sleep deprivation.