Publications by authors named "Carlos Coronel-Oliveros"

3 Publications

  • Page 1 of 1

Structural Features of the Human Connectome That Facilitate the Switching of Brain Dynamics via Noradrenergic Neuromodulation.

Front Comput Neurosci 2021 14;15:687075. Epub 2021 Jul 14.

Instituto Milenio Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.

The structural connectivity of human brain allows the coexistence of segregated and integrated states of activity. Neuromodulatory systems facilitate the transition between these functional states and recent computational studies have shown how an interplay between the noradrenergic and cholinergic systems define these transitions. However, there is still much to be known about the interaction between the structural connectivity and the effect of neuromodulation, and to what extent the connectome facilitates dynamic transitions. In this work, we use a whole brain model, based on the Jasen and Rit equations plus a human structural connectivity matrix, to find out which structural features of the human connectome network define the optimal neuromodulatory effects. We simulated the effect of the noradrenergic system as changes in filter gain, and studied its effects related to the global-, local-, and meso-scale features of the connectome. At the global-scale, we found that the ability of the network of transiting through a variety of dynamical states is disrupted by randomization of the connection weights. By simulating neuromodulation of partial subsets of nodes, we found that transitions between integrated and segregated states are more easily achieved when targeting nodes with greater connection strengths-local feature-or belonging to the rich club-meso-scale feature. Overall, our findings clarify how the network spatial features, at different levels, interact with neuromodulation to facilitate the switching between segregated and integrated brain states and to sustain a richer brain dynamics.
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http://dx.doi.org/10.3389/fncom.2021.687075DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8316621PMC
July 2021

Cholinergic neuromodulation of inhibitory interneurons facilitates functional integration in whole-brain models.

PLoS Comput Biol 2021 02 18;17(2):e1008737. Epub 2021 Feb 18.

Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile.

Segregation and integration are two fundamental principles of brain structural and functional organization. Neuroimaging studies have shown that the brain transits between different functionally segregated and integrated states, and neuromodulatory systems have been proposed as key to facilitate these transitions. Although whole-brain computational models have reproduced this neuromodulatory effect, the role of local inhibitory circuits and their cholinergic modulation has not been studied. In this article, we consider a Jansen & Rit whole-brain model in a network interconnected using a human connectome, and study the influence of the cholinergic and noradrenergic neuromodulatory systems on the segregation/integration balance. In our model, we introduce a local inhibitory feedback as a plausible biophysical mechanism that enables the integration of whole-brain activity, and that interacts with the other neuromodulatory influences to facilitate the transition between different functional segregation/integration regimes in the brain.
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http://dx.doi.org/10.1371/journal.pcbi.1008737DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7924765PMC
February 2021

Prenatal exposure to ketamine in rats: Implications on animal models of schizophrenia.

Dev Psychobiol 2018 01 24;60(1):30-42. Epub 2017 Nov 24.

Laboratorio de Neurociencias y Comportamiento (LabNeC), Centro de Estudios en Zoología Aplicada (CEZA), Facultad Experimental de Ciencias y Tecnología (FACyT), Universidad de Carabobo, Valencia, Venezuela.

Schizophrenia is a complex neuropsychiatric disorder characterized by hallucinations, delusions, anhedonia, flat affect and cognitive impairments. The aim of this study was to propose a prenatal treatment with ketamine, a psychedelic drug that acts as a non-competitive inhibitor of glutamate NMDA receptors, as a neurodevelopmental animal model of schizophrenia. The drug was applied (i.m. 60 mg.kg  h ) in pregnant Sprague-Dawley rats on gestational Day 14. Offspring behavior was studied on pubertal (4 weeks old) and adult (10 weeks old) stages. Also, hippocampal CA1-CA3 morphology was assessed in adult animals through a Nissl stain. Results showed a disinhibition and hyperactive behavior in pubertal animals exposed to ketamine, followed in adulthood with cognitive impairments, social withdrawal, anxiety, depression, and aggressive-like behaviors. In the hippocampus, a reduction of the CA3 layer thickness was observed, without changes in cell density. These results strongly suggest a robust link between prenatal pharmacologic manipulation of NMDA receptors and schizophrenia.
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http://dx.doi.org/10.1002/dev.21586DOI Listing
January 2018
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