System-level disruption of cortical temporal integration after stroke: linking intrinsic neural timescales to molecular and neurochemical architecture.

Abstract

Stroke disrupts the brain's ability to process and integrate information over time, yet the underlying molecular mechanisms remain unclear. This study investigates post-stroke alterations in intrinsic neural timescales (INTs)-a measure of regional temporal integration-by combining resting-state fMRI, spatial transcriptomics, and PET-based neurochemical mapping. Fifty acute ischemic stroke patients (within 7 days of onset) and fifty matched healthy controls were examined. Voxel-wise and network-level analyses revealed significantly reduced INTs in temporoparietal and insular cortices, with pronounced network-level impairments in the visual and cerebellar systems. Using data from the Allen Human Brain Atlas, we identified gene expression patterns associated with these disruptions. Genes negatively associated with INT reductions were enriched for synaptic, mitochondrial, and neurodevelopmental pathways, while positively associated genes reflected immune signaling and nuclear transport. INT alterations also correlated with excitatory and inhibitory neuronal signatures and were spatially aligned with GABA-A receptor density. Importantly, INT reductions showed significant correlations with clinical assessments: whole-brain INT correlated negatively with NIHSS (r = -0.41) and positively with MoCA (r = 0.38) and FMA (r = 0.35); SMN INT correlated with FMA motor subscore (r = 0.44); and regional INT correlated with domain-specific NIHSS subscores (neglect: r = -0.42; language: r = -0.38). These findings position INT as a clinically meaningful systems-level correlate of stroke-induced dysfunction and highlight molecular pathways and neurotransmitter systems that may constrain temporal integration and recovery potential.