Browsing by Author "Crossley Karmelic, Nicolas Andrés"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
- ItemBrain charts for the human lifespan(Springer, 2022) R. A. I. Bethlehem; J. Seidlitz; S. R. White; J. W. Vogel; K. M. Anderson; C. Adamson; S. Adler; G. S. Alexopoulos; E. Anagnostou; A. Areces-Gonzalez; D. E. Astle; B. Auyeung; M. Ayub; J. Bae; G. Ball; S. Baron-Cohen; R. Beare; S. A. Bedford; V. Benegal; Crossley Karmelic, Nicolas AndrésOver the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data (http://www.brainchart.io/). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.
- ItemComplexity and 1/f slope jointly reflect brain states(Nature Research, 2023) Medel, Vicente; Irani, Martín; Crossley Karmelic, Nicolas Andrés; Ossandon Valdés, Tomas; Boncompte Lezaeta, Gonzalo NicolasCharacterization of brain states is essential for understanding its functioning in the absence of external stimuli. Brain states differ on their balance between excitation and inhibition, and on the diversity of their activity patterns. These can be respectively indexed by 1/f slope and Lempel–Ziv complexity (LZc). However, whether and how these two brain state properties relate remain elusive. Here we analyzed the relation between 1/f slope and LZc with two in-silico approaches and in both rat EEG and monkey ECoG data. We contrasted resting state with propofol anesthesia, which directly modulates the excitation-inhibition balance. We found convergent results among simulated and empirical data, showing a strong, inverse and non trivial monotonic relation between 1/f slope and complexity, consistent at both ECoG and EEG scales. We hypothesize that differentially entropic regimes could underlie the link between the excitation-inhibition balance and the vastness of the repertoire of brain systems.
- ItemCountry-level gender inequality is associated with structural differences in the brains of women and men(National Academy of Sciences, 2023) Zugman, Andrés; Alliende, Luz María; Medel Sierralta, Vicente Nicolás; Bethlehem, Richard A. I.; Seidlitz, Jakob; Ringlein, Grace; Arango, Celso; Arnatkeviciutė, Aurina; Asmal, Laila; Bellgrove, Mark; Benegal, Vivek; Bernardo, Miquel; Billeke, Pablo; Bosch-Bayard, Jorge; Bressan, Rodrigo; Busatto, Geraldo F.; Castro, Mariana N.; Chaim-Avancini, Tiffany; Compte, Albert; Costanzi, Monise; Czepielewski, Leticia; Dazzan, Paola; Fuente-Sandoval, Camilo de la; Forti, Marta di; Díaz-Caneja, Covadonga M.; Díaz-Zuluaga, Ana María; Plessis, Stefan du; Duran, Fabio L. S.; Fittipaldi, Sol; Fornito, Alex; Freimer, Nelson B.; Gadelha, Ary; Gama, Clarissa S.; Garani, Ranjini; García-Rizo, Clemente; González Campo, Cecilia; González-Valderrama, Alfonso; Guinjoan, Salvador; Holla, Bharath; Ibáñez, Agustín; Jackowski, Andrea; Ivanovic, Daniza; León-Ortiz, Pablo; Lochner, Christine; López Jaramillo, Carlos; Luckhoff, Hilmar; Massuda, Raffael; McGuire, Philip; Miyata, Jun; Mizrahi, Romina; Murray, Robin; Ozerdem, Aysegul; Pan, Pedro M.; Parellada, Mara; Phahladira, Lebogan; Ramírez Mahaluf, Juan P.; Reckziegel, Ramiro; Marques Tiago Reis; Reyes-Madrigal, Francisco; Roos, Annerine; Rosa, Pedro; Salum, Giovanni; Scheffler, Freda; Schumann, Gunter; Serpa, Mauricio; Stein, Dan J.; Tepper, Angeles; Tiego, Jeggan; Ueno, Tsukasa; Undurraga, Juan; Undurraga, Eduardo A.; Valdés-Sosa, Pedro; Valli, Isabel; Villarreal, Mirta; Winton-Brown, Toby T.; Yalin, Nefize; Zamorano, Francisco; Zanetti, Marcus V.; Veda, C.; Winkler, Anderson M.; Pine, Daniel S.; Evans-Lacko, Sara; Crossley Karmelic, Nicolas AndrésGender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women’s worse outcomes in gender-unequal countries. We examined this through a random-effects meta-analysis on cortical thickness and surface area differences between adult healthy men and women, including a meta-regression in which country-level gender inequality acted as an explanatory variable for the observed differences. A total of 139 samples from 29 different countries, totaling 7,876 MRI scans, were included. Thickness of the right hemisphere, and particularly the right caudal anterior cingulate, right medial orbitofrontal, and left lateral occipital cortex, presented no differences or even thicker regional cortices in women compared to men in gender-equal countries, reversing to thinner cortices in countries with greater gender inequality. These results point to the potentially hazardous effect of gender inequality on women’s brains and provide initial evidence for neuroscience-informed policies for gender equality.
- ItemIs treatment-resistant schizophrenia associated with distinct neurobiological callosal connectivity abnormalities?(Cambridge University Press, 2021) Assunção-Leme, Idaiane Batista; Zugman, André; de Moura, Luciana Monteiro; Sato, João Ricardo; Higuchi, Cinthia; Ortiz, Bruno Bertolucci; Noto, Cristiano; Ota, Vanessa Kiyomi; Belangero, Sintia Iole; Bressan, Rodrigo A; Crossley Karmelic, Nicolas Andrés; Jackowski, Andrea P; Gadelha, Ary
- ItemPrevalence of depressive disorder in the adult population of Latin America: a systematic review and meta-analysis(Elsevier Ltd, 2023) Errázuriz Concha, Antonia; Avello-Vega, Dalia; Ramírez Mahaluf, Juan P.; Torres Barrenechea, Rafael; Crossley Karmelic, Nicolas Andrés; Undurraga Fourcade, Eduardo Andrés; Jones, Peter B.; Department of Psychiatry, School of Medicine, Pontificia Universidad Católica de Chile© 2023 The Author(s)Background: Depressive disorder is one of the leading causes of disability worldwide; however its prevalence and association with inequality and crime is poorly characterised in Latin America. This study aimed to: i. systematically review population-based studies of prevalence of ICD/DSM depressive disorder in Latin America, ii. report pooled regional, country, and sex-specific prevalence estimates, and iii. test its association with four country-level development indicators: human development (HDI), income (Gini) and gender inequality (GII), and intentional homicide rate (IHR). Methods: We conducted a systematic review and meta-analysis of population-based studies reporting primary data on the prevalence of ICD/DSM depressive disorder in Latin America from 1990 to 2023, irrespective of language. We searched PubMed, PsycINFO, Cochrane Library, SciELO (regional database), LILAC (regional database), and available grey literature. Study quality was assessed using JBI's critical appraisal tools. We generated pooled estimates using random-effects meta-analysis; heterogeneity was assessed using the I2 statistic. Meta-regression analyses were used to test associations of depression prevalence with indicators of inequality and human development. The study was registered with PROSPERO (CRD42019143054). Findings: Using data from 40 studies in Latin America, lifetime, 12-month, and current prevalence of ICD/DSM depressive disorder were calculated at 12.58% (95% CI 11.00%–14.16%); 5.30% (4.55–6.06%), and 3.12% (2.22–4.03), respectively. Heterogeneity was high across lifetime, 12-month, and current prevalence, sex, and countries. 12-month and current prevalence was associated with higher Gini and GII, 12-month prevalence with lower HDI, and current prevalence with higher IHR. Interpretation: We found a high prevalence of ICD/DSM depressive disorders in Latin America, and a statistically significant association with inequality and development indicators. The high heterogeneity found across prevalence periods and the major gaps in country representation underscore the need to escalate efforts to improve mental health access and research capabilities in Latin America. Systematic, comparable prevalence estimates would inform more effective decision-making in the region. Funding: Pfizer Independent Medical Education Grant.
- ItemThe ascending arousal system promotes optimal performance through mesoscale network integration in a visuospatial attentional task(The Mit Press, 2021) Wainstein Bezamat Gabriel; Rojas Libano, Daniel; Medel Sierralta, Vicente Nicolas; Alnaes, Dag; Kolskar, Knut K.; Endestad, Tor; Laeng, Bruno; Ossandon Valdes Tomas; Crossley Karmelic, Nicolas Andrés; Matar, Elie; Shine, James M.In our daily lives, it is usual to encounter highly demanding cognitive tasks. They have been traditionally regarded as challenges that are solved mainly through cerebral activity, specifically via information-processing steps carried by neurons in the cerebral cortex. Activity in cortical networks thus constitutes a key factor for improving our understanding of cognitive processes. However, recent evidence has shown that evolutionary older players in the central nervous system, such as brain stem's ascending modulatory systems, might play an equally important role in diverse cognitive mechanisms. Our article examines the role of the ascending arousal system on large-scale network dynamics by combining pupillometry, functional MRI, and graph theoretical analysis.
- ItemWhole-brain neuronal MCT2 lactate transporter expression links metabolism to human brain structure and function(National Academy of Sciences, 2022) Medel Sierralta, Vicente Nicolas; Crossley Karmelic, Nicolas Andrés; Gajardo, Ivana; Muller, Eli; Barros L., Felipe; Shine, James N.; Sierralta, JimenaBrain activity is constrained by local availability of chemical energy, which is generatedthrough compartmentalized metabolic processes. By analyzing data of whole humanbrain gene expression, we characterize the spatial distribution of seven glucose andmonocarboxylate membrane transporters that mediate astrocyte–neuron lactate shuttletransfer of energy. We found that the gene coding for neuronal MCT2 is the onlygene enriched in cerebral cortex where its abundance is inversely correlated withcortical thickness. Coexpression network analysis revealed that MCT2 was the onlygene participating in an organized gene cluster enriched in K+dynamics. Indeed, theexpression of KATPsubunits, which mediate lactate increases with spiking activity, isspatially coupled to MCT2 distribution. Notably, MCT2 expression correlated withfluorodeoxyglucose positron emission tomography task-dependent glucose utilization.Finally, the MCT2 messenger RNA gradient closely overlaps with functional MRI brainregions associated with attention, arousal, and stress. Our results highlight neuronalMCT2 lactate transporter as a key component of the cross-talk between astrocytes andneurons and a link between metabolism, cortical structure, and state-dependent brain function.