The subcortical belly of sleep: New possibilities in neuromodulation of basal ganglia?

Abstract

Early studies posited a relationship between sleep and the basal ganglia, but this relationship has received little attention recently. It is timely to revisit this relationship, given new insights into the functional anatomy of the basal ganglia and the physiology of sleep, which has been made possible by modern techniques such as chemogenetic and optogenetic mapping of neural circuits in rodents and intracranial recording, functional imaging, and a better understanding of human sleep disorders. We discuss the functional anatomy of the basal ganglia, and review evidence implicating their role in sleep. Whilst these studies are in their infancy, we suggest that the basal ganglia may play an integral role in the sleep-wake cycle, specifically by contributing to a thalamo-cortical-basal ganglia oscillatory network in slow-wave sleep which facilitates neural plasticity, and an active state during REM sleep which enables the enactment of cognitive and emotional networks. A better understanding of sleep mechanisms may pave the way for more effective neuromodulation strategies for sleep and basal ganglia disorders.

Keywords: Basal ganglia; Memory; Neuromodulation; Sleep.

Fig. 1

Relationships of the basal ganglia nuclei, with selected interactions between hypothalamus, thalamus, cerebellum and habenula. Abbreviations: DRN (dorsal raphe nucleus), GPe (globus pallidus externus, GPi (globus pallidus internus), PPN (pedunculopontine nucleus), RF (reticular formation), SNc (substantia nigra compacta), SNr (substantia nigra reticulata), STN (subthalamic nucleus), VTA (ventral tegmental area).

Fig. 2

Role of the basal ganglia in sleep pathways.