Jaime Fornaguera | Universidad de Costa Rica (original) (raw)

Papers by Jaime Fornaguera

Scientific Reports, 2019

The chronic unpredictable stress (CUS) paradigm is extensively used in preclinical research. Howe... more The chronic unpredictable stress (CUS) paradigm is extensively used in preclinical research. However, CUS exhibits translational inconsistencies, some of them resulting from the use of adult rodents, despite the evidence that vulnerability for many psychiatric disorders accumulates during early life. Here, we assessed the validity of the CUS model by including ethologically-relevant paradigms in juvenile rats. Thus, socially-isolated (SI) rats were submitted to CUS and compared with SI (experiment 1) and group-housed controls (experiment 1 and 2). We found that lower body-weight gain and hyperlocomotion, instead of sucrose consumption and preference, were the best parameters to monitor the progression of CUS, which also affected gene expression and neurotransmitter contents associated with that CUS-related phenotype. The behavioural characterisation after CUS placed locomotion and exploratory activity as the best stress predictors. By employing the exploratory factor analysis, we re...

Motor Activity and Movement Disorders, 1996

... As indicated in the previous example, this is the typical ipsiversive asymmetry of animals wi... more ... As indicated in the previous example, this is the typical ipsiversive asymmetry of animals with severe unilateral DA Page 181. Automated Video-Image Analysis 161 PRE APO I APO II APO III APO IV TEST 1234 1234 1234 1234 1234 MINUTES 1234 Fig. ...

Revista Mexicana de Neurociencia, Sep 26, 2017

Contribución original St. John's wort reverses anxiety-and depressive-like behaviors 2 La adminis... more Contribución original St. John's wort reverses anxiety-and depressive-like behaviors 2 La administración sub-crónica de hierba de San Juan revierte las conductas de ansiedad y depresión inducidas por dos protocolos distintos de estrés crónico. Sub-chronic administration of St. John's wort reverses anxiety-and depressive-like behaviors induced by two different protocols of chronic stress.

Neuroscience

Modern westernized diet is a major risk factor associated with the current obesity epidemic. To s... more Modern westernized diet is a major risk factor associated with the current obesity epidemic. To study the effects of dietary choices of Western societies, the cafeteria diet has been validated as a preclinical model of obesity. We aimed to investigate the behavioral and metabolic alterations induced by a cafeteria diet on gene expression and neurotransmitter contents involved in neural plasticity and reward processing. Male Wistar rats were exposed to either standard or cafeteria diet for 9 weeks. Food intake and body weight were scored daily. Behavioral effects were assessed in the elevated plus-maze (EPM) and open field (OFT) tests. Serum biochemical parameters, brain monoamines, and BDNF, TrkB, CRF, CREB, and Dnmt3A mRNA levels were analyzed in reward-related brain regions. We found that cafeteria-diet rats consumed more energy and food than the control group, leading to increased body weight gain and adiposity. The cafeteria-diet rats showed an anxiolytic-like effect in the OFT, but not in the EPM. The cafeteria diet increased BDNF expression in the dorsal striatum (DS), and norepinephrine, 5-HT, TrkB, CREB, and Dnmt3A levels in the hippocampus. Additionally, multiple regression analysis showed that accumbal DOPAC and BDNF mRNA levels were robustly predicted by hyperphagia, fat mass accumulation, and body weight gain only in the cafeteria group. Overall, cafeteria diet-induced hyperphagia could lead to alterations in hedonic and motivational control of food intake through changes in dopamine metabolism and BDNF signaling in the nucleus accumbens and the DS.

PLoS ONE, 2014

Between 10 and 25% of individuals with non-alcoholic fatty liver disease (NAFLD) develop hepatic ... more Between 10 and 25% of individuals with non-alcoholic fatty liver disease (NAFLD) develop hepatic fibrosis leading to cirrhosis and hepatocellular carcinoma (HCC). To investigate the molecular basis of disease progression, we performed a genome-wide analysis of copy number variation (CNV) in a total of 49 patients with NAFLD [10 simple steatosis and 39 nonalcoholic steatohepatitis (NASH)] and 49 matched controls using high-density comparative genomic hybridization (CGH) microarrays. A total of 11 CNVs were found to be unique to individuals with simple steatosis, whilst 22 were common between simple steatosis and NASH, and 224 were unique to NASH. We postulated that these CNVs could be involved in the pathogenesis of NAFLD progression. After stringent filtering, we identified four rare and/or novel CNVs that may influence the pathogenesis of NASH. Two of these CNVs, located at 13q12.11 and 12q13.2 respectively, harbour the exportin 4 (XPO4) and phosphodiesterase 1B (PDE1B) genes which are already known to be involved in the etiology of liver cirrhosis and HCC. Cross-comparison of the genes located at these four CNV loci with genes already known to be associated with NAFLD yielded a set of genes associated with shared biological processes including cell death, the key process involved in 'second hit' hepatic injury. To our knowledge, this pilot study is the first to provide CNV information of potential relevance to the NAFLD spectrum. These data could prove invaluable in predicting patients at risk of developing NAFLD and more importantly, those who will subsequently progress to NASH.

Behavioural Brain Research, 2001

In mice, the systemical or intracranial application of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-t... more In mice, the systemical or intracranial application of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) can lead to severe damage to the nigrostriatal dopaminergic system. This can result in a variety of symptoms concerning motor control resembling those in human Parkinson's disease, such as akinesia, rigidity, tremor, gait and posture disturbances. The aim of this work is to review a variety of behavioral paradigms for these and other symptoms, which have been used to characterize behavioral changes in mice after MPTP treatment. Main results are summarized, and general influential factors as well as potential problems in the experimental procedures are discussed, which should be taken into account when conducting behavioral analyses in mice with parkinsonian symptoms. Since there is reliable evidence (e.g. from strain comparisons) that the susceptibility of the nigrostriatal pathway to neurodegeneration is probably genetically influenced, relevant genes can be expected to be identified in the future. Therefore, the points discussed here will be useful not only for further applications in the MPTP mouse model, but also more generally for the behavioral characterization of future mouse models of PD, e.g. mice with a manipulation of genes relevant to the function of the basal ganglia.

Ciencia, Docencia y Tecnología, 2016

The use of technology has represented a change in several daily areas; like education. In prescho... more The use of technology has represented a change in several daily areas; like education. In preschool education case, technologic tools as computers insertion are proposed through the use of collaborative learning. Present research shows the result of the design of a collaborative game prototype, which supports collaboration among preschool children. Through focal groups, 21 teachers of two educative centers that specialize in preschool education in San Jose city in Costa Rica, participated as expert judgment and contributed in the scenario design, obstacles, music and textures of the game. These teachers also participated in workshops where three axes were developed: collaboration, technology and sociocognitive development. To validate aspects as esthetics and game dynamics, the game was evaluated by a group of children. As a result, the tool called “Sistema Solar” (Spanish for Solar System) was created: a virtual environment, where the contribution of three kids is necessary to reac...

Ambientes adversos tempranos pueden afectar el desarrollo del sistema nervioso e incluso favorece... more Ambientes adversos tempranos pueden afectar el desarrollo del sistema nervioso e incluso favorecer la aparicion de desordenes del estado de animo como la depresion y ansiedad. Esta hipotesis ha sido corroborada a traves de modelos animales. En un estudio reciente de nuestro laboratorio comparamos crias de ratas que recibieron de sus madres un bajo nivel de cuidado durante sus primeros dias de vida con otras que recibieron un alto nivel de cuidado. Cuando alcanzaron la adolescencia, las primeras presentaron mayores niveles de ansiedad y una mayor adquisicion de conductas que se han relacionado con la depresion. Este estudio permitio tambien observar cambios neurofisiologicos en los mismos animales. Los resultados obtenidos confirman la influencia del cuidado materno en el desarrollo y sus efectos a largo plazo.

Revista Costarricense de Psicología, 2016

EspañolLa discusión en torno a la influencia del ambiente sobre la ontogenia ha alimentado la int... more EspañolLa discusión en torno a la influencia del ambiente sobre la ontogenia ha alimentado la interrogante sobre cuál es el grado en el que, a través de la manipulación del contexto, se modifican las características de los individuos. Actualmente, la evidencia científica desde distintos campos (e.g., Psicología del desarrollo, Neurociencias) describe cómo el ambiente es capaz de modular los procesos del desarrollo y las distintas capacidades del cerebro, así como los mecanismos plásticos que subyacen a dicha modulación. Con base en esta evidencia, distintas aproximaciones metodológicas orientadas a la estimulación temprana (ET) se han propuesto potenciar el desarrollo o remediar problemas que se presentan durante las etapas tempranas del ciclo vital. En este contexto, se brinda una revisión del tema y se ofrece un marco teórico general sobre los antecedentes y sobre los principios que sustentan la estimulación del sistema nervioso (i.e., plasticidad cerebral). Además, a través de un...

Frontiers in Pharmacology, 2020

Behavioural Processes, 2018

Animal models of fear and anxiety provide important insight into anxiety-related symptoms in huma... more Animal models of fear and anxiety provide important insight into anxiety-related symptoms in humans. Environmental physical conditions and social contact influence behavior and brain plasticity particularly at early developmental stages and have long lasting effects reaching even adulthood. The potential benefit that a later environmental enrichment may have on rats raised in isolation is however not fully understood. We aim to investigate the effects of housing conditions and their reversion on anxiety and fear-related behaviors in rats. In phase I, we compared the effects of different housing conditions (environmental enrichment, control and social isolation) on anxiety behaviors in the open field test, elevated plus maze and fear conditioning. We found stronger effects of housing on behavioral tests when induced at weaning (phase I), than later in development (phase II). After one month, EE rats showed lower anxiety related behaviors and more freezing in FC. In phase II, we evaluated the effects of the reversion of housing conditions on the same behavioral parameters. We observed a behavioral trend such that the groups started to behave similar to their new housing conditions in OFT mainly. These results suggest that housing conditions at weaning can have long-lasting effects on anxiety and fear-related behaviors. Because the behavioral changes observed after the housing reversal in adulthood were partial, we suggest that more time of social and physical enrichment could be necessary to promote major changes in behavior at this age.

Current topics in behavioral neurosciences, Jan 29, 2016

Psychosocial stress is capable of causing immune dysregulation and increased neuroinflammatory si... more Psychosocial stress is capable of causing immune dysregulation and increased neuroinflammatory signaling by repeated activation of the neuroendocrine and autonomic systems that may contribute to the development of anxiety and depression. The stress model of repeated social defeat (RSD) recapitulates many of the stress-driven alterations in the neuroimmune system seen in humans experiencing repeated forms of stress and associated affective disorders. For example, RSD-induced neuronal and microglia activation corresponds with sympathetic outflow to the peripheral immune system and increased ability of bone marrow derived myeloid progenitor cells (MPC) to redistribute throughout the body, including to the central nervous system (CNS), reinforcing stress-associated behaviors. An overview of the neuroendocrine, immunological, and behavioral stress-induced responses will be reviewed in this chapter using RSD to illustrate the mechanisms leading to stress-related alterations in inflammatio...