Functional Connectivity of Human Striatum: A Resting State fMRI Study

TLDR

The basal ganglia, traditionally viewed as motor structures, also support cognitive, motivational, and emotional functions, and dysfunction is linked to many neurological and psychiatric disorders, yet models largely rely on animal inference despite advances in human neuroimaging. The study aims to map basal ganglia circuitry in humans during rest. This is achieved via resting‑state fMRI functional connectivity analysis. Voxelwise regression confirmed motor, cognitive, and affective divisions of striatal subregions and revealed finer distinctions—such as inferior ventral striatum connectivity with medial orbitofrontal cortex versus superior ventral striatum with medial and lateral orbitofrontal cortex—supporting parallel and integrative loop models and highlighting resting‑state fMRI’s potential for studying basal ganglia dysfunction.

Abstract

Classically regarded as motor structures, the basal ganglia subserve a wide range of functions, including motor, cognitive, motivational, and emotional processes. Consistent with this broad-reaching involvement in brain function, basal ganglia dysfunction has been implicated in numerous neurological and psychiatric disorders. Despite recent advances in human neuroimaging, models of basal ganglia circuitry continue to rely primarily upon inference from animal studies. Here, we provide a comprehensive functional connectivity analysis of basal ganglia circuitry in humans through a functional magnetic resonance imaging examination during rest. Voxelwise regression analyses substantiated the hypothesized motor, cognitive, and affective divisions among striatal subregions, and provided in vivo evidence of a functional organization consistent with parallel and integrative loop models described in animals. Our findings also revealed subtler distinctions within striatal subregions not previously appreciated by task-based imaging approaches. For instance, the inferior ventral striatum is functionally connected with medial portions of orbitofrontal cortex, whereas a more superior ventral striatal seed is associated with medial and lateral portions. The ability to map multiple distinct striatal circuits in a single study in humans, as opposed to relying on meta-analyses of multiple studies, is a principal strength of resting state functional magnetic resonance imaging. This approach holds promise for studying basal ganglia dysfunction in clinical disorders.