Changes in dynamic transitions between integrated and segregated states underlie visual hallucinations in Parkinson’s disease
Angeliki Zarkali, Andrea I. Luppi, Emmanuel A. Stamatakis, Suzanne Reeves, Peter McColgan, Louise-Ann Leyland, Andrew J. Lees, Rimona S. Weil
Communications Biology September 8, 2022 DOI: 10.1038/s42003-022-03903-x (opens in new tab) via Springer Nature
Summary
AI-generated from the abstractPeople with Parkinson's disease who experience hallucinations spend more time in a brain state where regions are functionally segregated from one another and make fewer transitions between brain states. The shift from an integrated to a segregated state requires less energy in those who hallucinate, making that state potentially preferable. The regional energy needed for this transition correlates with neurotransmitter density and gene expression for serotoninergic, GABAergic, noradrenergic, and cholinergic receptors, but not dopaminergic receptors. The findings suggest that neurochemistry and brain structure together shape the dynamic brain states that underlie hallucinations.
Study at a glance
| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Population | People with Parkinson's disease who experience hallucinations |
| Key finding | Parkinson's-hallucinators spent more time in a predominantly Segregated functional state with fewer between-state transitions, and the transition from integrated-to-segregated state had lower energy cost. |
Abstract
Hallucinations are a core feature of psychosis and common in Parkinson’s. Their transient, unexpected nature suggests a change in dynamic brain states, but underlying causes are unknown. Here, we examine temporal dynamics and underlying structural connectivity in Parkinson’s-hallucinations using a combination of functional and structural MRI, network control theory, neurotransmitter density and genetic analyses. We show that Parkinson’s-hallucinators spent more time in a predominantly Segregated functional state with fewer between-state transitions. The transition from integrated-to-segregated state had lower energy cost in Parkinson’s-hallucinators; and was therefore potentially preferable. The regional energy needed for this transition was correlated with regional neurotransmitter density and gene expression for serotoninergic, GABAergic, noradrenergic and cholinergic, but not dopaminergic, receptors. We show how the combination of neurochemistry and brain structure jointly shape functional brain dynamics leading to hallucinations and highlight potential therapeutic targets by linking these changes to neurotransmitter systems involved in early sensory and complex visual processing. The examination of temporal dynamics in Parkinson’s-hallucinations reveals that the combination of neurochemistry and brain structure jointly shape functional brain dynamics leading to hallucinations.