Biology subjects

Ladouceur, C. D.

Publications and source records attributed to Ladouceur, C. D..

4 recordsLinked to original sources

bioRxiv2025

Differential Cerebral White Matter Tract Alterations in Generalized Anxiety Disorder Revealed by Ultra-High Field 7T Diffusion-Weighted Imaging

BackgroundGeneralized anxiety disorder (GAD) is characterized by chronic worry and emotional dysregulation, yet its underlying white matter (WM) architecture remains inconsistent in previous neuroimaging studies. This study aimed to delineate microstructural WM alterations in GAD using ultra-high field (7T) diffusion tensor imaging (DTI) and advanced correlational tractography, evaluating their associations with symptom severity and diagnostic-aided value. MethodsEighty-eight participants (27 GAD, 61 healthy controls, HCs) underwent 7T DTI scanning with 1.5-mm isotropic resolution. Whole-brain correlational tractography was applied to identify tracts exhibiting significant group-related differences in diffusion indices while controlling for demographic covariates. Associations with Hamilton Anxiety Rating Scale (HAM-A) and Penn State Worry Questionnaire (PSWQ) scores were examined, and machine learning-based models were used to assess the diagnostic-aided utility of identified WM features. ResultsTwo tract bundles showed significant fractional anisotropy (FA) alterations in GAD: decreased FA in the right prefrontal pathway (PFDR = 0.039) and increased FA in the right cingulum (PFDR < 0.001). The anterior portions of both tracts exhibited stronger effects of GAD. FA in the right cingulum positively correlated with HAM-A and PSWQ scores, indicating that greater microstructural coherence was associated with higher anxiety and worry severity (both PFDRs < 0.001). Inclusion of WM features could improve classification performance beyond neuropsychological measures alone. ConclusionsUltra-high field 7T tractometry revealed a differential pattern of WM abnormalities in GAD, suggesting weakened prefrontal control and hyper-integrated cingulate connectivity as structural correlates of emotional dysregulation. These findings indicate the potential of 7T DTI markers for advancing mechanistic and diagnostic understanding of GAD.

neuroscience↗

bioRxiv2025

Adolescent girls at familial risk for depression with more advanced adrenarche have altered gut microbiota

ObjectivesRates of adolescent depression are rising, especially among girls, with children of depressed parents facing a three times higher risk. Emerging evidence suggests a link between gut microbiota, neural function, and depression risk, possibly through pathways that involve brain-body interactions, including the vagus nerve. During adolescence, sex-specific changes in the microbiota align with pubertal development, although their connection to depression vulnerability remains unclear. We compared gut microbiota in adolescents at high and low familial risk for depression and explored whether differences are affected by vagal activity and pubertal stage. MethodsWe collected clinical assessments, physiological data, and stool samples from 52 adolescents (aged 9-15, including 31 females), consisting of 27 high-risk and 25 low-risk individuals. We used 16S rRNA marker gene sequencing to analyze the diversity, structure, composition, and predicted function of the microbial community. A laboratory stressor task was employed to examine changes in vagally mediated heart rate variability (stress reactivity). Regressions were used to assess the relationship between depression risk, gut microbiota, and cardiovascular stress reactivity indices. Exploratory analyses investigated the effects of sex, age, and pubertal stage (adrenarche and gonarche). ResultsHigh-risk adolescents exhibited a distinct gut microbiota profile compared to low-risk adolescents, with this effect primarily driven by female participants. This profile was characterized by a higher abundance of Prevotella, which was 2-fold higher in high-risk females, and lower levels of other beneficial genera. High-risk females were also significantly more advanced in adrenarcheal development; the link between depression risk and adrenarcheal development was mediated by gut microbiota in females. Cardiovascular stress reactivity did not differ between groups and was not linked to gut microbiota. ConclusionsOur results reveal sex-specific links between depression risk, adrenarcheal development, and gut microbiota in adolescence. The increase of Prevotella in high-risk females suggests inflammation-related pathways may connect familial vulnerability to mood disorders. Future long-term studies examining hormones, microbiota, and mood during pubertal changes are essential to determine causality and develop targeted treatments.

neuroscience↗

bioRxiv2023

The association between cortical gyrification and sleep in adolescents and young adults.

Study objectivesHealthy sleep is important for adolescent neurodevelopment, and relationships between brain structure and sleep can vary in strength over this maturational window. Although cortical gyrification is increasingly considered a useful index for understanding cognitive and emotional outcomes in adolescence, and sleep is also a strong predictor of such outcomes, we know relatively little about associations between cortical gyrification and sleep. MethodsUsing Local gyrification index (lGI) of 34 bilateral brain regions and regularized regression for feature selection, we examined gyrification-sleep relationships in the Neuroimaging and Pediatric Sleep databank (252 participants; 9-26 years; 58.3% female) and identified developmentally invariant (stable across age) or developmentally specific (observed only during discrete age intervals) brain-sleep associations. Naturalistic sleep characteristics (duration, timing, continuity, and regularity) were estimated from wrist actigraphy. ResultsFor most brain regions, greater lGI was associated with longer sleep duration, earlier sleep timing, lower variability in sleep regularity, and shorter time awake after sleep onset. lGI in frontoparietal network regions showed associations with sleep patterns that were stable across age. However, in default mode network regions, lGI was only associated with sleep patterns from late childhood through early-to-mid adolescence, a period of vulnerability for mental health disorders. ConclusionsWe detected both developmentally invariant and developmentally specific ties between local gyrification and naturalistic sleep patterns. Default mode network regions may be particularly susceptible to interventions promoting more optimal sleep during childhood and adolescence.

neuroscience↗

bioRxiv2021

Associations between brain structure and sleep patterns across adolescent development

ImportanceStructural brain maturation and sleep are complex processes that exhibit significant changes over adolescence and are linked to healthy physical and mental development. The precise timing and magnitude of these changes influence function throughout the lifespan. However, the relationships between gray matter structure and sleep patterns during adolescence are not fully understood. A detailed characterization of brain-sleep associations during this sensitive period is crucial for understanding factors contributing to optimal neurodevelopmental trajectories in adolescence. ObjectiveTo investigate whether sleep-gray matter relationships are developmentally-invariant (i.e., stable across age) or developmentally-specific (i.e., only present during discrete time windows) from late childhood through young adulthood. SettingThe Neuroimaging and Pediatric Sleep Databank was constructed from 8 research studies conducted at the University of Pittsburgh between 2009 and 2020. ParticipantsThe final sample consisted of 240 participants without current psychiatric diagnoses (9-25 years), and with good quality sleep tracking and structural MRI (sMRI) data. DesignParticipants completed a sMRI scan and 5-7 days of wrist actigraphy to assess naturalistic sleep. We examined cross-sectional associations between sMRI measures and sleep patterns, as well as the effects of age, sex, and their interaction with sMRI measures on sleep. Main Outcome(s) and Measure(s)Using Freesurfer software, we extracted cortical thickness and subcortical volumes from T1-weighted MRI. Sleep patterns (duration, timing, continuity, regularity) were estimated from wrist actigraphy. ResultsShorter sleep duration, later sleep timing, and poorer sleep continuity were associated with a stable pattern of thinner cortex and altered subcortical volumes in diverse brain regions across adolescence. In a discrete subset of regions (e.g., posterior cingulate), thinner cortex was associated with these sleep patterns from late childhood through early-to-mid adolescence, but not in late adolescence and young adulthood. Conclusions and RelevanceIn childhood and adolescence, developmentally-invariant and developmentally-specific associations exist between sleep patterns and gray matter structure, in a wide array of brain regions linked to many sensory, cognitive, and emotional processes. Sleep intervention during specific developmental periods could potentially promote healthier neurodevelopmental outcomes. KEY POINTSO_ST_ABSQuestionC_ST_ABSDoes age modulate associations between gray matter structure and actigraphic sleep patterns across adolescent development? FindingsThis cross-sectional study reports stable associations between regional gray matter structure and shorter duration, later timing, and poorer continuity of sleep from ages 9 to 25 years-old, as well as developmentally-specific associations that are present only from late childhood to early-to-mid adolescence. MeaningStronger coupling of gray matter and sleep patterns from late childhood to early-to-mid adolescence potentially implicates this discrete developmental window as a period of vulnerability to adverse sleep-brain interactions. Sleep intervention during this developmental stage may support healthier neurodevelopmental trajectories.

neuroscience↗