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.
Shaogao Gui, Zhan-Xiang Hu, Yuan-Zhi He et al.· Brain Research· 0 citations
Major depressive disorder (MDD) is characterized by dysfunction in higher-order cortical regions involved in emotional and cognitive processes; however, its neurobiological basis remains unclear. Pharmacological treatments, including esketamine and sertraline, produce rapid antidepressant effects. We investigated the local intrinsic neural dynamics underlying these antidepressant effects using intrinsic neural timescales (INT), which measure the duration and capacity of information integration in localized brain regions.
A total of 57 healthy controls and 41 patients with MDD were included. All patients with MDD received six intravenous infusions of esketamine (0.25 mg/kg) and two weeks of sertraline treatment. All participants underwent resting-state fMRI to quantify INT alterations at the voxel and brain network levels, followed by spatial correlation analyses linking autocorrelation metrics of INT signals to transcriptomic data from the Allen Human Brain Atlas and PET-derived neurotransmitter receptor maps. The spatial correlation between PLS2 scores and case–control t-statistic maps did not pass rigorous spin permutation testing (
r
= 0.484,
p
= 0.068) and did not meet the conventional significance threshold of 0.05. Accordingly, all subsequent enrichment analyses based on PLS2 results are presented as exploratory preliminary observations for hypothesis generation.
Compared with healthy controls, patients with MDD exhibited significantly elevated INT levels in the left and right precuneus. Following treatment, patients with MDD showed significantly increased INT in the left occipital midline region and left calcarine cortex. At the brain network level, INT levels were significantly reduced in the default mode network (DMN) in patients with MDD compared with healthy controls. Compared with the pre-treatment state, the cerebellar network (CN) showed significantly elevated INT levels after treatment. Partial least squares regression analysis suggested potential associations between INT alterations and spatial gene expression gradients particularly those associated with immune responses, hormonal regulation, neutrophils, regulatory T cells, and glutamatergic synapses. Cell-type enrichment analysis identified excitatory and inhibitory neurons as key cellular contributors. Alterations in INT also correlated with cortical 5-HT1b and NAT receptor density, suggesting a role for inhibitory neurotransmission in temporal integration deficits.
This study advances understanding of treatment-related brain abnormalities in patients with MDD from the perspective of local neural dynamics. These findings support a multiscale pathophysiological framework involving brain connectivity dynamics, molecular architecture, and neurochemical regulation in MDD.
Xiang Liu, Yuanzhi He, Lifeng Li et al.· BMC Psychiatry· 0 citations
