Author name cluster

Gabriel A. Devenyi

Possible papers associated with this exact author name in Arrow. This page groups case-insensitive exact name matches and is not a full identity disambiguation profile.

13 papers

1 author row

YNIMG Journal 2023 Journal Article

A cross-sectional and longitudinal study of human brain development: The integration of cortical thickness, surface area, gyrification index, and cortical curvature into a unified analytical framework

Hadis Kalantar-Hormozi
Raihaan Patel
Alyssa Dai
Justine Ziolkowski
Hao-Ming Dong
Avram Holmes
Armin Raznahan
Gabriel A. Devenyi

Brain maturation studies typically examine relationships linking a single morphometric feature with cognition, behavior, age, or other demographic characteristics. However, the coordinated spatiotemporal arrangement of morphological features across development and their associations with behavior are unclear. Here, we examine covariation across multiple cortical features (cortical thickness [CT], surface area [SA], local gyrification index [GI], and mean curvature [MC]) using magnetic resonance images from the NIMH developmental cohort (ages 5-25). Neuroanatomical covariance was examined using non-negative matrix factorization (NMF), which decomposes covariance resulting in a parts-based representation. Cross-sectionally, we identified six components of covariation which demonstrate differential contributions of CT, GI, and SA in hetero- vs. unimodal areas. Using this technique to examine covariance in rates of change to identify longitudinal sources of covariance highlighted preserved SA in unimodal areas and changes in CT and GI in heteromodal areas. Using behavioral partial least squares (PLS), we identified a single latent variable (LV) that recapitulated patterns of reduced CT, GI, and SA related to older age, with limited contributions of IQ and SES. Longitudinally, PLS revealed three LVs that demonstrated a nuanced developmental pattern that highlighted a higher rate of maturational change in SA and CT in higher IQ and SES females. Finally, we situated the components in the changing architecture of cortical gradients. This novel characterization of brain maturation provides an important understanding of the interdependencies between morphological measures, their coordinated development, and their relationship to biological sex, cognitive ability, and the resources of the local environment.

Details DOI

YNIMG Journal 2023 Journal Article

Examining litter specific variability in mice and its impact on neurodevelopmental studies

Vanessa Valiquette
Elisa Guma
Lani Cupo
Daniel Gallino
Chloe Anastassiadis
Emily Snook
Gabriel A. Devenyi
M. Mallar Chakravarty

Our current understanding of litter variability in neurodevelopmental studies using mice may limit translation of neuroscientific findings. Higher variance of measures across litters than within, often termed intra-litter likeness, may be attributable to both pre- and postnatal environment. This study aimed to assess the litter-effect within behavioral assessments (2 timepoints) and anatomy using T1-weighted magnetic resonance images across 72 brain region volumes (4 timepoints) (36 C57bl/6J inbred mice; 7 litters: 19F/17M). Between-litter comparisons of brain and behavioral measures and their associations were evaluated using univariate and multivariate techniques. A power analysis using simulation methods was then performed on modeled neurodevelopment and to evaluate trade-offs between number-of-litters, number-of-mice-per-litter, and sample size. Our results show litter-specific developmental effects, from the adolescent period to adulthood for brain structure volumes and behaviors, and for their associations in adulthood. Our power simulation analysis suggests increasing the number-of-litters in experimental designs to achieve the smallest total sample size necessary for detecting different rates of change in specific brain regions. Our results demonstrate how litter-specific effects may influence development and that increasing the litters to the total sample size ratio should be strongly considered when designing neurodevelopmental studies.

Details DOI

YNIMG Journal 2022 Journal Article

Inter- and intra-individual variation in brain structural-cognition relationships in aging

Raihaan Patel
Clare E. Mackay
Michelle G. Jansen
Gabriel A. Devenyi
M. Clare O'Donoghue
Mika Kivimäki
Archana Singh-Manoux
Enikő Zsoldos

The sources of inter- and intra-individual variability in age-related cognitive decline remain poorly understood. We examined the association between 20-year trajectories of cognitive decline and multimodal brain structure and morphology in older age. We used the Whitehall II Study, an extensively characterised cohort with 3T brain magnetic resonance images acquired at older age (mean age = 69.52 ± 4.9) and 5 repeated cognitive performance assessments between mid-life (mean age = 53.2 ±4.9 years) and late-life (mean age = 67.7 ± 4.9). Using non-negative matrix factorization, we identified 10 brain components integrating cortical thickness, surface area, fractional anisotropy, and mean and radial diffusivities. We observed two latent variables describing distinct brain-cognition associations. The first describes variations in 5 structural components associated with low mid-life performance across multiple cognitive domains, decline in reasoning, but maintenance of fluency abilities. The second describes variations in 6 structural components associated with low mid-life performance in fluency and memory, but retention of multiple abilities. Expression of latent variables predicts future cognition 3.2 years later (mean age = 70.87 ± 4.9). This data-driven approach highlights brain-cognition relationships wherein individuals degrees of cognitive decline and maintenance across diverse cognitive functions are both positively and negatively associated with markers of cortical structure.

Details DOI

YNICL Journal 2021 Journal Article

Cumulative exposure to ADHD medication is inversely related to hippocampus subregional volume in children

Nellie H. Fotopoulos
Gabriel A. Devenyi
Stephanie Guay
Sarojini M. Sengupta
M. Mallar Chakravarty
Natalie Grizenko
Sherif Karama
Ridha Joober

BACKGROUND: Although there is some evidence for a normalization of brain structure following exposure to ADHD medication, literature on the effects of duration and dose of continued use on the brain is scarce. Here, we investigated the association between cumulative exposure to medication (range 1 week to 4.69 years) and cortical structures and subcortical volumes in a clinical sample of children with ADHD taking medication (n = 109). To the best of our knowledge, this is the first structural MRI study investigating the effects of cumulative exposure to medication on subregional volumes in children treated for ADHD. METHODS: Cumulative exposure to ADHD medication (CEM) was defined as the product of duration on medication (days) and dose (mg/day), yielding the area under the curve (total mg). Cortical thickness and surface area measurements (CIVET-1.1.12), and subcortical volumes in 51 regions (MAGeT-Brain) were analyzed using general linear modelling. RESULTS: Significant effects of CEM were found in two subregions of the left hippocampus, the CA1 (df = 95; q = 0.003) and the strata radiatum/lacunosum/moleculare (df = 95; q = 0.003). Specifically, higher CEM was associated with smaller volumes within these subregions. No effects of medication exposure were detected on cortical thickness or surface area. CONCLUSIONS: Although this study is cross-sectional, the results found within this sample of children show that prolonged ADHD medication use at higher doses is significantly associated with smaller hippocampus volumes in specific subregions. More research is required to determine whether these results are reproduced in other samples of children of ADHD, and further, whether these are beneficial or off-target effects of the medication.

Details DOI

YNIMG Journal 2021 Journal Article

Hippocampal subfield volumes across the healthy lifespan and the effects of MR sequence on estimates

Aurélie Bussy
Eric Plitman
Raihaan Patel
Stephanie Tullo
Alyssa Salaciak
Saashi A. Bedford
Sarah Farzin
Marie-Lise Béland

The hippocampus has been extensively studied in various neuropsychiatric disorders throughout the lifespan. However, inconsistent results have been reported with respect to which subfield volumes are most related to age. Here, we investigate whether these discrepancies may be explained by experimental design differences that exist between studies. Multiple datasets were used to collect 1690 magnetic resonance scans from healthy individuals aged 18–95 years old. Standard T1-weighted (T1w; MPRAGE sequence, 1 mm3 voxels), high-resolution T2-weighted (T2w; SPACE sequence, 0. 64 mm3 voxels) and slab T2-weighted (Slab; 2D turbo spin echo, 0. 4 × 0. 4 × 2 mm3 voxels) images were included. The MAGeT Brain algorithm was used for segmentation of the hippocampal grey matter (GM) subfields and peri-hippocampal white matter (WM) subregions. Linear mixed-effect models and Akaike information criterion were used to examine linear, second or third order natural splines relationship between hippocampal volumes and age. We demonstrated that stratum radiatum/lacunosum/moleculare and fornix subregions expressed the highest relative volumetric decrease, while the cornus ammonis 1 presented a relative volumetric preservation of its volume with age. We also found that volumes extracted from slab images demonstrated different age-related relationships compared to volumes extracted from T1w and T2w images. The current work suggests that although T1w, T2w and slab derived subfield volumetric outputs are largely homologous, modality choice plays a meaningful role in the volumetric estimation of the hippocampal subfields.

Details DOI

YNICL Journal 2021 Journal Article

Subtle alterations in neonatal neurodevelopment following early or late exposure to prenatal maternal immune activation in mice

Elisa Guma
Emily Snook
Shoshana Spring
Jason P. Lerch
Brian J. Nieman
Gabriel A. Devenyi
M. Mallar Chakravarty

Prenatal exposure to maternal immune activation (MIA) is a risk factor for a variety of neurodevelopmental and psychiatric disorders. The timing of MIA-exposure has been shown to affect adolescent and adult offspring neurodevelopment, however, less is known about these effects in the neonatal period. To better understand the impact of MIA-exposure on neonatal brain development in a mouse model, we assess neonate communicative abilities with the ultrasonic vocalization task, followed by high-resolution ex vivo magnetic resonance imaging (MRI) on the neonatal (postnatal day 8) mouse brain. Early exposed offspring displayed decreased communicative ability, while brain anatomy appeared largely unaffected, apart from some subtle alterations. By integrating MRI and behavioural assays to investigate the effects of MIA-exposure on neonatal neurodevelopment we show that offspring neuroanatomy and behaviour are only subtly affected by both early and late exposure. This suggests that the deficits often observed in later stages of life may be dormant, not yet developed in the neonatal period, or not as easily detectable using a cross-sectional approach.

Details DOI

YNIMG Journal 2021 Journal Article

The impact of the Siemens Tim Trio to Prisma upgrade and the addition of volumetric navigators on cortical thickness, structure volume, and 1H-MRS indices: An MRI reliability study with implications for longitudinal study designs

Eric Plitman
Aurélie Bussy
Vanessa Valiquette
Alyssa Salaciak
Raihaan Patel
Lani Cupo
Marie-Lise Béland
Stephanie Tullo

H-MRS analyses. Further, CT estimates were found to be larger in MPRAGE acquisitions compared to vNav-MPRAGE acquisitions mainly within temporal areas, while the opposite was found mostly in parietal brain regions. The results from this work should be considered in longitudinal study designs and comparable prospective motion correction investigations are warranted in cases of marked head movement.

Details DOI

YNICL Journal 2020 Journal Article

Deformation-based shape analysis of the hippocampus in the semantic variant of primary progressive aphasia and Alzheimer’s disease

Marianne Chapleau
Christophe Bedetti
Gabriel A. Devenyi
Signy Sheldon
Howie J. Rosen
Bruce L. Miller
Maria Luisa Gorno-Tempini
Mallar M. Chakravarty

BACKGROUND: Increasing evidence shows that the semantic variant of primary progressive aphasia (svPPA) is characterized by hippocampal atrophy. However, less is known about disease-related morphological hippocampal changes. The goal of the present study is to conduct a detailed characterization of the impact of svPPA on global hippocampus volume and morphology compared with control subjects and patients with Alzheimer's disease (AD). METHODS: We measured hippocampal volume and deformation-based shape differences in 22 patients with svPPA compared with 99 patients with AD and 92 controls. Multiple Automatically Generated Templates Brain Segmentation Algorithm (MAGeT-Brain) was used on MRI images obtained at the diagnostic visit. RESULTS: Comparable left and right hippocampal atrophy were observed in svPPA and AD. Deformation-based shape analysis showed a common pattern of morphological deformation in svPPA and AD compared with controls. More specifically, both svPPA and AD showed inward deformations in the dorsal surface of the hippocampus, from head to tail on the left side, and more limited to the anterior portion of the body in the right hemisphere. These results also pointed out that both diseases are characterized by a lateral displacement of the central part (body) of the hippocampus. DISCUSSION: Our study provides critical new evidence of hippocampal morphological changes in svPPA, similar to those found in AD. These findings highlight the importance of considering morphological hippocampal changes as part of the anatomical profile of patients with svPPA.

Details DOI

YNIMG Journal 2020 Journal Article

Investigating microstructural variation in the human hippocampus using non-negative matrix factorization

Raihaan Patel
Christopher J. Steele
Anthony G.X. Chen
Sejal Patel
Gabriel A. Devenyi
Jürgen Germann
Christine L. Tardif
M. Mallar Chakravarty

In this work we use non-negative matrix factorization to identify patterns of microstructural variance in the human hippocampus. We utilize high-resolution structural and diffusion magnetic resonance imaging data from the Human Connectome Project to query hippocampus microstructure on a multivariate, voxelwise basis. Application of non-negative matrix factorization identifies spatial components (clusters of voxels sharing similar covariance patterns), as well as subject weightings (individual variance across hippocampus microstructure). By assessing the stability of spatial components as well as the accuracy of factorization, we identified 4 distinct microstructural components. Furthermore, we quantified the benefit of using multiple microstructural metrics by demonstrating that using three microstructural metrics (T1-weighted/T2-weighted signal, mean diffusivity and fractional anisotropy) produced more stable spatial components than when assessing metrics individually. Finally, we related individual subject weightings to demographic and behavioural measures using a partial least squares analysis. Through this approach we identified interpretable relationships between hippocampus microstructure and demographic and behavioural measures. Taken together, our work suggests non-negative matrix factorization as a spatially specific analytical approach for neuroimaging studies and advocates for the use of multiple metrics for data-driven component analyses.

Details DOI

YNICL Journal 2019 Journal Article

Contributions of a high-fat diet to Alzheimer's disease-related decline: A longitudinal behavioural and structural neuroimaging study in mouse models

Colleen P.E. Rollins
Daniel Gallino
Vincent Kong
Gülebru Ayranci
Gabriel A. Devenyi
Jürgen Germann
M. Mallar Chakravarty

Obesity is recognized as a significant risk factor for Alzheimer's disease (AD). Studies have supported that obesity accelerates AD-related pathophysiology and memory impairment in mouse models of AD. However, the nature of the brain structure-behaviour relationship mediating this acceleration remains unclear. In this manuscript we evaluated the impact of adolescent obesity on the brain morphology of the triple transgenic mouse model of AD (3xTg) and a non-transgenic control model of the same background strain (B6129s) using longitudinally acquired structural magnetic resonance imaging (MRI). At 8 weeks of age, animals were placed on a high-fat diet (HFD) or an ingredient-equivalent control diet (CD). Structural images were acquired at 8, 16, and 24 weeks. At 25 weeks, animals underwent the novel object recognition (NOR) task and the Morris water maze (MWM) to assess short-term non-associative memory and spatial memory, respectively. All analyses were carried out across four groups: B6129s-CD and -HFD and 3xTg-CD and -HFD. Neuroanatomical changes in MRI-derived brain morphology were assessed using volumetric and deformation-based analyses. HFD-induced obesity during adolescence exacerbated brain volume alterations by adult life in the 3xTg mouse model in comparison to control-fed mice and mediated volumetric alterations of select brain regions, such as the hippocampus. Further, HFD-induced obesity aggravated memory in all mice, lowering certain memory measures of B6129s control mice to the level of 3xTg mice maintained on a CD. Moreover, decline in the volumetric trajectories of hippocampal regions for all mice were associated with the degree of spatial memory impairments on the MWM. Our results suggest that obesity may interact with the brain changes associated with AD-related pathology in the 3xTg mouse model to aggravate brain atrophy and memory impairments and similarly impair brain structural integrity and memory capacity of non-transgenic mice. Further insight into this process may have significant implications in the development of lifestyle interventions for treatment of AD.

Details DOI

YNIMG Journal 2018 Journal Article

Evaluating accuracy of striatal, pallidal, and thalamic segmentation methods: Comparing automated approaches to manual delineation

Carolina Makowski
Sophie Béland
Penelope Kostopoulos
Nikhil Bhagwat
Gabriel A. Devenyi
Ashok K. Malla
Ridha Joober
Martin Lepage

Accurate automated quantification of subcortical structures is a greatly pursued endeavour in neuroimaging. In an effort to establish the validity and reliability of these methods in defining the striatum, globus pallidus, and thalamus, we investigated differences in volumetry between manual delineation and automated segmentations derived by widely used FreeSurfer and FSL packages, and a more recent segmentation method, the MAGeT-Brain algorithm. In a first set of experiments, the basal ganglia and thalamus of thirty subjects (15 first episode psychosis [FEP], 15 controls) were manually defined and compared to the labels generated by the three automated methods. Our results suggest that all methods overestimate volumes compared to the manually derived “gold standard”, with the least pronounced differences produced using MAGeT. The least between-method variability was noted for the striatum, whereas marked differences between manual segmentation and MAGeT compared to FreeSurfer and FSL emerged for the globus pallidus and thalamus. Correlations between manual segmentation and automated methods were strongest for MAGeT (range: 0. 51 to 0. 92; p<0. 01, corrected), whereas FreeSurfer and FSL showed moderate to strong Pearson correlations (range 0. 44–0. 86; p<0. 05, corrected), with the exception of FreeSurfer pallidal (r=0. 31, p=0. 10) and FSL thalamic segmentations (r=0. 37, p=0. 051). Bland-Altman plots highlighted a tendency for greater volumetric differences between manual labels and automated methods at the lower end of the distribution (i. e. smaller structures), which was most prominent for bilateral thalamus across automated pipelines, and left globus pallidus for FSL. We then went on to examine volume and shape of the basal ganglia structures using automated techniques in 135 FEP patients and 88 controls. The striatum and globus pallidus were significantly larger in FEP patients compared to controls bilaterally, irrespective of the method used. MAGeT-Brain was more sensitive to shape-based group differences, and uncovered widespread surface expansions in the striatum and globus pallidus bilaterally in FEP patients compared to controls, and surface contractions in bilateral thalamus (FDR-corrected). By contrast, after using a recommended cluster-wise thresholding method, FSL only detected differences in the right ventral striatum (FEP>Control) and one cluster of the left thalamus (Control>FEP). These results suggest that different automated pipelines segment subcortical structures with varying degrees of variability compared to manual methods, with particularly pronounced differences found with FreeSurfer and FSL for the globus pallidus and thalamus.

Details DOI

YNIMG Journal 2018 Journal Article

Manual segmentation of the fornix, fimbria, and alveus on high-resolution 3T MRI: Application via fully-automated mapping of the human memory circuit white and grey matter in healthy and pathological aging

Robert S.C. Amaral
Min Tae M. Park
Gabriel A. Devenyi
Vivian Lynn
Jon Pipitone
Julie Winterburn
Sofia Chavez
Mark Schira

Recently, much attention has been focused on the definition and structure of the hippocampus and its subfields, while the projections from the hippocampus have been relatively understudied. Here, we derive a reliable protocol for manual segmentation of hippocampal white matter regions (alveus, fimbria, and fornix) using high-resolution magnetic resonance images that are complementary to our previous definitions of the hippocampal subfields, both of which are freely available at https: //github. com/cobralab/atlases. Our segmentation methods demonstrated high inter- and intra-rater reliability, were validated as inputs in automated segmentation, and were used to analyze the trajectory of these regions in both healthy aging (OASIS), and Alzheimer's disease (AD) and mild cognitive impairment (MCI; using ADNI). We observed significant bilateral decreases in the fornix in healthy aging while the alveus and cornu ammonis (CA) 1 were well preserved (all p's<0. 006). MCI and AD demonstrated significant decreases in fimbriae and fornices. Many hippocampal subfields exhibited decreased volume in both MCI and AD, yet no significant differences were found between MCI and AD cohorts themselves. Our results suggest a neuroprotective or compensatory role for the alveus and CA1 in healthy aging and suggest that an improved understanding of the volumetric trajectories of these structures is required.

Details DOI

YNIMG Journal 2018 Journal Article

Regional brain volume changes following chronic antipsychotic administration are mediated by the dopamine D2 receptor

Elisa Guma
Jill Rocchetti
Gabriel A. Devenyi
Arnaud Tanti
Axel Mathieu
Jason P. Lerch
Guillaume Elgbeili
Blandine Courcot

Background Neuroanatomical alterations are well established in patients suffering from schizophrenia, however the extent to which these changes are attributable to illness, antipsychotic drugs (APDs), or their interaction is unclear. APDs have been extremely effective for treatment of positive symptoms in major psychotic disorders. Their therapeutic effects are mediated, in part, through blockade of D2-like dopamine (DA) receptors, i. e. the D2, D3 and D4 dopamine receptors. Furthermore, the dependency of neuroanatomical change on DA system function and D2-like receptors has yet to be explored. Methods We undertook a preclinical longitudinal study to examine the effects of typical (haloperidol (HAL)) and atypical (clozapine (CLZ)) APDs in wild type (WT) and dopamine D2 knockout (D2KO) mice over 9-weeks using structural magnetic resonance imaging (MRI). Results Chronic typical APD administration in WT mice was associated with reductions in total brain (p = 0. 009) and prelimbic area (PL) (p = 0. 02) volumes following 9-weeks, and an increase in striatal volume (p = 0. 04) after six weeks. These APD-induced changes were not present in D2KOs, where, at baseline, we observed significantly smaller overall brain volume (p < 0. 01), thinner cortices (q < 0. 05), and enlarged striata (q < 0. 05). Stereological assessment revealed increased glial density in PL area of HAL treated wild types. Interestingly, in WT and D2KO mice, chronic CLZ administration caused more limited changes in brain structure. Conclusions Our results present evidence for the role of D2 DA receptors in structural alterations induced by the administration of the typical APD HAL and that chronic administration of CLZ has a limited influence on brain structure.

Details DOI