Amin Saberi

I am a PhD student at the Cognitive Neurogenetics Lab led by Dr. Sofie Valk and situated at the Max Planck Institute for Human Cognitive and Brain Sciences and Research Center Jülich (INM-7).

My research is focused on using computational neuroscience techniques on neuroimaging data to study the low-dimensional structural and functional properties of the brain and their links to behavior and psychiatric disorders. I am also interested in open and reproducible science, as well as developing and improving tools for analyzing brain data.

Previously, I have studied medicine at the Mashhad University of Medical Sciences (2011-2019), followed by a research stay at the Institute of Medical Science and Technology at Shahid Beheshti University (2019-2021) under the supervision of Dr. Masoud Tahmasian.

selected publications

Convergent functional effects of antidepressants in major depressive disorder: a neuroimaging meta-analysis Saberi A, Ebneabbasi A, Rahimi S, Sarebannejad S, Sen Z, Graf H, Walter M, Sorg C, Camilleri J, Laird A, Fox P, Valk S, Eickhoff S, and Tahmasian M^* Molecular Psychiatry 2024 [abstract] [url] [pdf]
Neuroimaging studies have provided valuable insights into the macroscale impacts of antidepressants on brain functions in patients with major depressive disorder. However, the findings of individual studies are inconsistent. Here, we aimed to provide a quantitative synthesis of the literature to identify convergence of the reported findings at both regional and network levels and to examine their associations with neurotransmitter systems.
Adolescent Maturation of Cortical Excitation-Inhibition Balance Based on Individualized Biophysical Network Modeling Saberi A, Wischnewski K, Jung K, Lotter L, Schaare H, Banaschewski T, Barker G, Bokde A, Desrivières S, Flor H, Grigis A, Garavan H, Gowland P, Heinz A, Brühl R, Martinot J, Martinot M, Artiges E, Nees F, Orfanos D, Lamaitre H, Poustka L, Hohmann S, Holz N, Baeuchl C, Smolka M, Vaidya N, Walter H, Whelan R, Schumann G, Consortium I, Paus T, Dukart J, Bernhardt B, Popovych O, Eickhoff S, and Valk S^* bioRxiv 2024 [abstract] [url] [pdf]
The balance of excitation and inhibition is a key functional property of cortical microcircuits which changes through the lifespan. Adolescence is considered a crucial period for the maturation of excitation-inhibition balance. This has been primarily observed in animal studies, yet human in vivo evidence on adolescent maturation of the excitation-inhibition balance at the individual level is limited. Here, we developed an individualized in vivo marker of regional excitation-inhibition balance in human adolescents, estimated using large-scale simulations of biophysical network models fitted to resting-state functional magnetic resonance imaging data from two independent cross-sectional (N = 752) and longitudinal (N = 149) cohorts. We found a widespread relative increase of inhibition in association cortices paralleled by a relative age-related increase of excitation, or lack of change, in sensorimotor areas across both datasets. This developmental pattern co-aligned with multiscale markers of sensorimotor-association differentiation. The spatial pattern of excitation-inhibition development in adolescence was robust to inter-individual variability of structural connectomes and modeling configurations. Notably, we found that alternative simulation-based markers of excitation-inhibition balance show a variable sensitivity to maturational change. Taken together, our study highlights an increase of inhibition during adolescence in association areas using cross sectional and longitudinal data, and provides a robust computational framework to estimate microcircuit maturation in vivo at the individual level.
The regional variation of laminar thickness in the human isocortex is related to cortical hierarchy and interregional connectivity Saberi A, Paquola C, Wagstyl K, Hettwer M, Bernhardt B, Eickhoff S, and Valk S^* PLOS Biology 2023 [abstract] [url] [pdf]
The human isocortex consists of tangentially organized layers with unique cytoarchitectural properties. These layers show spatial variations in thickness and cytoarchitecture across the neocortex, which is thought to support function through enabling targeted corticocortical connections. Here, leveraging maps of the 6 cortical layers based on 3D human brain histology, we aimed to quantitatively characterize the systematic covariation of laminar structure in the cortex and its functional consequences. After correcting for the effect of cortical curvature, we identified a spatial pattern of changes in laminar thickness covariance from lateral frontal to posterior occipital regions, which differentiated the dominance of infra- versus supragranular layer thickness. Corresponding to the laminar regularities of cortical connections along cortical hierarchy, the infragranular-dominant pattern of laminar thickness was associated with higher hierarchical positions of regions, mapped based on resting-state effective connectivity in humans and tract-tracing of structural connections in macaques. Moreover, we show that regions with similar laminar thickness patterns have a higher likelihood of structural connections and strength of functional connections. In sum, here, we characterize the organization of laminar thickness in the human isocortex and its association with cortico-cortical connectivity, illustrating how laminar organization may provide a foundational principle of cortical function.
Structural and functional neuroimaging of late-life depression: a coordinate-based meta-analysis Saberi A, Mohammadi E, Zarei M, Eickhoff S, and Tahmasian M^* Brain Imaging and Behavior 2021 [abstract] [url] [pdf]
Several neuroimaging studies have investigated localized aberrations in brain structure, function or connectivity in late-life depression, but the ensuing results are equivocal and often conflicting. Here, we provide a quantitative consolidation of neuroimaging in late-life depression using coordinate-based meta-analysis by searching multiple databases up to March 2020. Our search revealed 3252 unique records, among which we identified 32 eligible whole-brain neuroimaging publications comparing 674 patients with 568 controls. The peak coordinates of group comparisons between the patients and the controls were extracted and then analyzed using activation likelihood estimation method. Our sufficiently powered analysis on all the experiments, and more homogenous subsections of the data (patients \textgreater controls, controls \textgreater patients, and functional imaging experiments) revealed no significant convergent regional abnormality in late-life depression. This inconsistency might be due to clinical and biological heterogeneity of LLD, as well as experimental (e.g., choice of tasks, image modalities) and analytic flexibility (e.g., preprocessing and analytic parameters), and distributed patterns of neural abnormalities. Our findings highlight the importance of clinical/biological heterogeneity of late-life depression, in addition to the need for more reproducible research by using pre-registered and standardized protocols on more homogenous populations to identify potential consistent brain abnormalities in late-life depression.