Neuroimaging Projects in Latin America

1/12/2022

Latin America (LATAM) is a region formed by countries and territories united by romance languages and a similarly complicated history of colonization by Spain, Portugal and France. LATAM spans from Mexico in North America to Central and South America, as well as countries in the Caribbean like Cuba. Most countries in LATAM are considered as developing: their academic and research funding is usually lower than developed countries, and 3 Tesla MRI scanners are usually found in hospitals and shared by researchers and clinicians, a situation that is always challenging. Some countries even have only a single 3T MRI scanner. That said, there have been great efforts by neuroimaging groups in the last 20 years to develop research and education. Researchers in LATAM who studied neuroimaging in the US, Canada or Europe, came back and have been training new students and developing their own research, usually building MRI labs from scratch. Now, there is a new generation of LATAM trained researchers pushing the field forward. Here, we consider how researchers from these countries have grown and developed neuroimaging research in the region.

LATAM has always been a melting pot for ethnicities and cultures, and it is now an important region for scientific endeavour due to its unique demographic, linguistic, genetic and cultural diversity. This means that not only large-scale neuroimaging projects are in the works, but also unique studies and study samples, from domains such as psychology, anthropology, the arts and health. Notably, LATAM researchers are known for excellent international collaborations. With this in mind, I would like to provide an overview of some of the neuroimaging projects and researchers in LATAM by country, with the hope of future scientific collaboration between these and other countries. This is not a comprehensive list, and this work was possible thanks to those researchers who responded to my emails and Twitter announcement.

MEXICO

Sarael Alcauter, PhD, is an Assistant Professor at the Institute of Neurobiology, Universidad Nacional Autónoma de México (UNAM) campus Juriquilla in Querétaro, México. This institute focuses on the study of different aspects of neuroscience, from molecular to cellular levels, up to the study of higher functions such as cognition and behavior. Sarael leads the neuroimaging section of the consortium TWINSMX: “A twins registry is an epidemiological research tool that allows us to analyze the proportion of the variability of a trait related to genetic or environmental factors.

Because every population is specific, it was important to create a Mexican database, as Mexico has a unique genetic and cultural mixture of at least 3 roots: Pre-columbian indigenous, Spanish and African. We plan to explore brain structure and function of identical and fraternal twins, to study heritability and ambientality of several of their properties. We will also explore diverse relationships between structure and function, and physical and mental health in the Mexican population”.

Camilo de la Fuente Sandoval, MD, PhD, is the Scientific Director at the National Institute of Neurology and Neurosurgery in Mexico City and interested in first episode psychosis: “We study glutamate and GABA abnormalities to serve as biomarkers of conversion risk in ultra-high risk subjects and of treatment response in early stage schizophrenia. We have a target sample size of 90 Mexican patients, with 63 already acquired for this project. To obtain brain GABA and Glx data, we use MRI spectroscopy.

The standard J-edited spin echo difference method was implemented to target a 3.0 x 2.5 x 2.5 cm^3 mPFC voxel and a 4.5 x 2.5 x 2.0 cm^3 voxel prescribed to include primarily the dorsal caudate bilaterally, with the inferior edge of the voxel positioned 3mm dorsal to the anterior commissure. We are also part of the ENIGMA Clinical High Risk for Psychosis Working Group”.

Florencia Assaneo Verona, PhD, is an Associate Professor at the Institute of Neurobiology, Universidad Nacional Autónoma de México (UNAM) campus Juriquilla in Querétaro, México , and leader of the Speech Perception and Production Laboratory: “We study speech processing and production using different techniques like M/EEG. Specifically, we are interested in the regularities in the envelope of the acoustic signal that correlate with syllabic information and that play a central role in production and perception processes.

We argue that the speech motor cortex is best modeled as a neural oscillator that explains speech perception-production interaction, and that speech production yields a stable rate that is faithfully recovered by the perception system, subserving the successful comprehension of spoken language.”

Luis Concha, MD, PhD, is also an Associate Professor at the Institute of Neurobiology (INB), UNAM and Leader of the Brain Connectivity Lab and the National Laboratory for MRI: “The work we develop along with Dr. Hiram Luna and graduate students is aimed at understanding the genesis and evolution of particular forms of epilepsy. To this end, we use diffusion-weighted MRI (dMRI) and other forms of quantitative imaging. Our work has shown associations between brain connectivity and cognitive performance in patients with epilepsy. Since some questions cannot be answered through the study of clinical populations, we also use animal models to follow and understand the process of epileptogenesis. Because dMRI is a rapidly-evolving field, and as this method holds promise as a powerful tool to infer information regarding tissue microstructure, I’m also interested in testing and validating the true extent of such promise.

Through studies in rodents, our lab has shown that certain methods such as multi-tensor approaches and constrained spherical deconvolution can indeed correctly identify and individually assess intact and damaged axonal populations even when they intermingle within a single image voxel, while providing raw and processed dMRI and histology for the community to further validate other methods that may be developed in the near future”.

Alonso Ramírez-Manzanares, PhD, is an Associate Professor at the Department of Computer Science, Research Center in Mathematics (CIMAT) in Guanajuato, Guanajuato: “Inside the Computer Science department, we integrate the Medical Imaging Processing Group. Among the research topics that are conducted, we can find the microstructure characterization of brain white matter tissue from diffusion-weighted MR data.

In particular, our group focuses on the estimation of axon bundle descriptors at the mesoscale (e.g. the “MRDS” method), as well as on the computation of microstructural indexes of axonal density and axonal orientation dispersion (as for instance the “ED^3” method). By globally integrating the local descriptors of brain tissue, one can generate information about brain connectivity on the scale of millimeters (this process is known as "brain tractography"). In this field, our group has been working on the development of methods to robustly estimate the cortico-cortical neural connections (e.g. the “Flocking Tractography” method) and also in the characterization of the topological features of the brain connectomes (graphs built based on neurological global connectivity). The majority of the research methods are developed with the objective to be applied in clinical settings, that is to say, the methods should work on scenarios with realistic levels of machine noise and with a small as possible number of MR acquisitions or images.”

Eduardo Garza-Villarreal, MD, PhD, is an Assistant Professor at the Institute of Neurobiology UNAM: “With my research group, PsiLANTRO Lab, we are working in translational research, using neuroimaging as a possible biomarker in substance use disorders (SUDs) and between species, as we work with rodents, non-human primates (MRI data only) and humans. We are especially interested in the convergence and divergence of the development of SUDs between different species, and the mechanisms and effects of neuromodulation techniques such as repetitive transcranial magnetic stimulation (rTMS) in SUDs.

Our first Open Access database is available in OpenNeuro, the SUDMEX_CONN: The Mexican dataset of cocaine use disorder patients. We are also working on an rTMS study in alcohol use disorder in humans, a rat model of alcohol use disorder with longitudinal neuroimaging, and cross species study of the reward system between non-human primates and humans with Sze Chai Kwok at Duke Kunshan University in Shanghai, China. Finally, we are part of the ENIGMA Addiction Working Group”.

COLOMBIA

Yakeel Quiroz-Gaviria, PhD, is an Associate Professor of Psychology in the Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, in Boston, USA, and is currently working as the lead investigator with Professor Francisco Lopera from the Universidad de Antioquia in Medellín, Colombia.

“Since 2014 we have been doing a longitudinal neuroimaging and biomarker study, the Colombia-Boston (COLBOS) longitudinal biomarker study of autosomal-dominant Alzheimer’s disease, which follows individuals from the world’s largest extended family with a single, AD-causing mutation (E280A in Presenilin1). This is an international collaboration, where members of Colombian families with genetic mutations for Alzheimer’s disease complete clinical and cognitive evaluations as well as structural and functional MRI, as well as PET studies for amyloid and tau, every 18 months. All MRI studies are done at the Hospital Pablo Tobon Uribe-HPTU in Medellin, and analyzed by the Colombian group. PET studies are done and analyzed at MGH in Boston and Martinos Center respectively”.

In Bogota, Pablo Reyes, PhD is an Assistant Professor at the Hospital Universitario San Ignacio y la Pontificia Universidad Javeriana in Bogotá, Columbia: “I work on processing and analysis of clinical and basic research neuroimaging data in several themes, leading a group called Perspectives in Neuroscience, Psychiatry and Aging. Lately, I’ve been collaborating in a multicentric dementia project called Research Dementia Latin America (ReDLat). I’m also working on a neuroimaging help website for Spanish speakers.”

URUGUAY

Victoria Gradin, PhD is an Associate Professor at the Centro de Investigación Básica en Psicología, Faculty of Psychology of the Universidad de la República in Montevideo, Uruguay: “In my work, I am trying to understand the neural basis of mental disorders, in particular, depression. In order to get started with cognitive neuroscience projects, I started using EEG. Then, we established a collaboration with the Uruguayan center that owned the only 3T scanner in the country, and built an fMRI set up and we are now running the first fMRI projects of our country.

Our main goal is to investigate the decision-making and neural substrates associated with mental health disorders, such as depression and social anxiety. In the last few years, we have specially focused on the neural mechanisms underlying social difficulties in these populations. This is relevant as depression and social anxiety have a profound impact on social functioning. In the last few years, the need for studying social interactions across mental disorders using experimental tasks that actively recreate interactions and immerse the participant in a social context has been emphasized. In our group, we use multiplayer tasks from behavioural economics, as well as tasks designed in our group, to recreate social scenarios that allow studying brain activation during active social exchanges. One of our current projects examines the neural basis of social comparison processes in depression and social anxiety.”

BRAZIL

Ricardo João Sato, PhD is an Assistant Professor at the Brazilian National Institute of Developmental Psychiatry in São Paulo, Brazil, an institute focused on the mental health of children and adolescents: “The researchers here are looking for substantial evidence that mental disorders are related to atypical neurodevelopmental trajectories. A detailed description of the cohort protocols is published in Salum et al. (2015).

This is a communitary sample composed of 2512 (random = 958; high risk = 1554) participants (from two Brazilian cities: São Paulo and Porto Alegre), who were assessed by psychiatric diagnosis. A subsample of more than 700 subjects participated in a complementary neuroimaging and blood biomarkers data acquisition.”

Carlos Ernesto Garrido Salmon, PhD and Renata Ferranti Leoni, PhD from the InBrain Lab (Universidade de São Paulo, Ribeirão Preto, Brazil): “We work on the study of functional and structural properties of the brain through application of non-invasive physics techniques aimed at obtaining basic knowledge and methods for neuroscience and neuroradiology.

Main lines of research include neurovascular metabolic coupling (TMS, EEG, fMRI, NIRS, ASL, fMRS), structural and functional connectivity in brain normal aging (DTI, fMRI, EEG, ASL, TMS), quantitative magnetic resonance imaging techniques (relaxometry, magnetization transfer, diffusion, MRS, fMRI) to characterize central nervous system diseases (epilepsy, Alzheimer's disease, stroke, multiple sclerosis, Parkinson's disease) and assess paramagnetic ion content in the human brain, and neurofeedback.”

CHILE

The Latin American Brain Health Institute (BrainLat) aims to empower innovative brain health research leaders across Latin America, in full integration with leading centers worldwide. BrainLat seeks to transcend disciplinary boundaries, forge groundbreaking investigations, and reduce the regional impact of dementia. This mission benefits from a partnership with the Global Brain Health Institute (GBHI) at the University of California, San Francisco (UCSF) and Trinity College Dublin (TCD).

Agustín Ibañez, PhD is one of the directors of the project Multi-Partner Consortium to Expand Dementia Research in Latin America (ReDLat), which is a massive project. “This project fosters a consortium of multiple partners aimed to expand dementia research in Latin America and the Caribbean (LAC). The consortium aims to combine genomic, neuroimaging and behavioral data to improve dementia characterization in diverse populations.

This 5-year project constitutes an excellent opportunity to foster regional synergy and multidisciplinary research to promote harmonization of global strategies to treat and prevent dementia in underserved populations.

ReDLat will develop an innovative, harmonized, and cross-regional approach on two of their most prevalent neurodegenerative disorders: Alzheimer’s disease (AD) and frontotemporal dementia (FTD). This project is also led by directors Jennifer Yokoyama, Kate Possin, Kenneth Kosik, Victor Valcour, and Bruce Miller, with support from NIH/NIA, Alzheimer’s Association, Tau Consortium and GBHI”. Other projects from Agustín include the use of high density EEG and deep learning to find multi-feature biomarkers in dementia.

ARGENTINA

Valeria Della-Maggiore, PhD, is the Director of the Physiology Action Lab and Professor at the Faculty of Medicine, Universidad de Buenos Aires: “Our research focuses on the behavioral neuroscience of motor control. We use non-invasive human brain mapping techniques such as transcranial magnetic stimulation (TMS), magnetic resonance imaging (MRI) and electroencephalography (EEG) to study the contribution of the motor system to different aspects of motor control and motor learning. We are also working on memory consolidation and retention during sleep and wakeful states.

Our work showed that when adapting to conflicting perturbations, impairments in performance are driven by two distinct mechanisms: a long-lasting bias that hinders initial performance, and a short-lasting anterograde interference that originates from a reduction in error-sensitivity. ” Valeria and her team just received the Susanne Klein-Vogelbach Prize in ‘Research on Human Movement’ for her work.

The summary above illustrates the depth and breadth of neuroimaging research in LATAM. This is, of course, not a complete overview and there is plenty of work going on in LATAM that was not exhibited here. We hope that this gives other researchers an idea of the type of neuroimaging research being developed and conducted in this vast region of the world.

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