Corrigendum: Clinical and genetic analysis of Costa Rican patients with Parkinson's disease.

[This corrects the article DOI: 10.3389/fneur.2021.656342.].

Clinical and Genetic Analysis of Costa Rican Patients With Parkinson's Disease.

Background: Most research in genomics of Parkinson's disease (PD) has been done in subjects of European ancestry, leading to sampling bias and leaving Latin American populations underrepresented. We sought to clinically characterize PD patients of Costa Rican origin and to sequence familial PD and atypical parkinsonism-associated genes in cases and controls. Methods: We enrolled 118 PD patients with 97 unrelated controls. Collected information included demographics, exposure to risk and protective factors, and motor and cognitive assessments. We sequenced coding and untranslated regions in familial PD and atypical parkinsonism-associated genes including GBA, SNCA, VPS35, LRRK2, GCH1, PRKN, PINK1, DJ-1, VPS13C, and ATP13A2. Results: Mean age of PD probands was 62.12 ± 13.51 years; 57.6% were male. The frequency of risk and protective factors averaged ~45%. Physical activity significantly correlated with better motor performance despite years of disease. Increased years of education were significantly associated with better cognitive function, whereas hallucinations, falls, mood disorders, and coffee consumption correlated with worse cognitive performance. We did not identify an association between tested genes and PD or any damaging homozygous or compound heterozygous variants. Rare variants in LRRK2 were nominally associated with PD; six were located between amino acids p.1620 and 1623 in the C-terminal-of-ROC (COR) domain of Lrrk2. Non-synonymous GBA variants (p.T369M, p.N370S, and p.L444P) were identified in three healthy individuals. One PD patient carried a pathogenic GCH1 variant, p.K224R. Discussion: This is the first study that describes sociodemographics, risk factors, clinical presentation, and genetics of Costa Rican patients with PD, adding information to genomics research in a Latino population.

A Protocol to Perform Systemic Lipopolysacharide (LPS) Challenge in Rats / Protocolo para realizar reto sistémico con lipopolisacárido (LPS) en ratas

Abstract 19. Lipopolysaccharide (LPS) is a component of the outer membrane of Gram-negative bacteria. In animals, intraperitoneal administration of LPS, stimulates innate immunity and the production of proinflammatory cytokines. LPS provides an inflammatory stimulus that activates the neuroimmune and neuroendocrine systems resulting in a set of responses termed sickness behavior. The purpose of this protocol is to describe step-by-step the preparation and procedure of application of intraperitoneal injection of LPS in rats, as a guide for those researchers that want to use this assay to mount an inflammatory response. LPS intraperitoneal challenge in rats has been widely used to evaluate antiinflammatory reagents and to address basic scientific questions.

Resumen 23. El lipopolisacárido (LPS) es un componente de la membrana externa de las bacterias Gram negativas. En animales, la administración intraperitoneal de LPS estimula la inmunidad innata y la producción de citoquinas proinflamatorias. El LPS proporciona un estímulo inflamatorio que activa el sistema neuroinmunológico y el sistema neuroendocrino, lo que da como resultado un conjunto de respuestas denominadas conductas de enfermedad. El propósito de este protocolo es describir paso a paso la preparación y el procedimiento de aplicación de la inyección intraperitoneal de LPS en ratas, como una guía para aquellos investigadores que desean utilizar este método para estimular una respuesta inflamatoria en el animal. La estimulación con LPS en ratas, aplicada intraperitonealmente, se ha utilizado ampliamente para evaluar reactivos antiinflamatorios y para abordar preguntas básicas de investigación científica.

Estandarización de un protocolo de inmunohistoquímica para detectar microglia del cerebro de ratas de la cepa Wistar

bjetivo: Estandarizar un protocolo de inmunohistoquímica que se ha utilizado ampliamente en ratones de la cepa C57BL/6J para identificar microglia del sistema nervioso central en ratas de la cepa Wistar. Materiales y Métodos: La presente actividad de investigación se llevó a cabo en dos partes. En la primera parte se implementó un protocolo de inmunohistoquímica para identificar la microglia en el sistema nervioso central de 6 ratas de la cepa Wistar. Se utilizó un anticuerpo primario para rata y un anticuerpo secundario específico para el primario. Una vez establecido el protocolo en cerebro de ratas, se pasó a la segunda parte en donde se produjo un reto inmunológico con la aplicación intraperitoneal de lipopolisacárido en 2 ratas de la cepa Wistar, con el fin de evidenciar los cambios en la morfología de la microglia. Resultados y Discusión: Demostramos que sin realizar grandes modificaciones al protocolo original, este también puede utilizarse para la identificación de microglia en ratas adultas de la cepa Wistar. El establecimiento de este protocolo permitirá estudiar de una mejor manera la interacción bidireccional que se da entre el cerebro y el sistema inmunológico, en condiciones homeostáticas y ante diferentes estímulos fisiológicos y patológicos.

bjective: Standardize a protocol of immunohistochemistry that has been widely used in C57BL/6J mice to identify microglia of the central nervous system in Wistar rats. Materials and Methods: This research activity was carried out in two parts. In the first part, a protocol of immunohistochemistry was implemented to identify microglia in the central nervous system of 6 Wistar rats. A primary antibody with reactivity to rat and a specific secondary antibody to the primary were used. Once the protocol was established in rats' brains, an immunological challenge was produced with the intraperitoneal application of lipopolysaccharide in 2 Wistar rats, in order to evidence the changes in microglia morphology. Results and Discussion: We demonstrate that without making major modifications to the original protocol, it can also be used to identify microglia in adult Wistar rats. In the near future, this immunostaining protocol will be applied to elucidate the bidirectional interaction between the brain and the immune system, under homeostatic conditions and different physiological and pathological stimuli.

Stress-Induced Microglia Activation and Monocyte Trafficking to the Brain Underlie the Development of Anxiety and Depression.

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 inflammation in both the periphery and CNS, and stress-related changes in behavioral responses.

De la neuroplasticidad a las propuestas aplicadas: estimulación temprana y su implementación en Costa Rica / From Neuroplasticity to Applied Proposals: Early Stimulation and Its Implementation in Costa Rica

Resumen La 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 una aproximación empírica y un proceso de revisión bibliográfica, se presenta la evidencia disponible de algunos de los métodos de mayor conocimiento/uso en Costa Rica (i.e., Doman- Delacato, Snoezelen®, Point y Bebé Políglota). Al recapitular los alcances y las limitaciones de la ET, se concluye que es necesario sistematizar las experiencias profesionales de forma tal que permitan abrir un debate académico sobre el tema.

Abstract The discussion about environmental influence on ontogeny has fueled the question about how much context manipulation can regulate individuals' characteristics. Today, scientific evidence from different fields (e.g., developmental psychology, neuroscience) describes not only how environment can modulate brain development and function, but also the plastic mechanisms involved. In consequence, different methodological approximations of early stimulation (ES) have arisen, although they are not necessarily based on solid empirical evidence. In this context, a brief approximation to the ES background is provided, as well as a general framework about brain plasticity. In addition, the theoretical and practical perspective of the ES practitioners is also described by detailing the empirical evidence around its most known/used variants in Costa Rica (i.e., Doman-Delacato, Snoezelen®, Point and Bebé políglota). Finally, bringing up the scope and limitations of ES, we conclude that the professional experiences need to be systematized, in order to open an academic debate on the subject.

Age-dependent effects of environmental enrichment on spatial memory and neurochemistry.

Although aging and environmental stimulation are well-known to affect cognitive abilities, the question of whether aging effects can be distinguished in already-mature adult rats has not been fully addressed. In the present study, therefore, young and mature adult rats were housed in either enriched or standard conditions (EE or SC) for three months. Open-field (OFT) and radial-maze (RM) behavior, and ex-vivo contents of GABA and glutamate in hippocampus, and of dopamine and DOPAC in ventral striatum (VS) were analyzed and compared between the four groups. In OFT, young rats were more active than mature adults irrespective of the housing condition. Surprisingly, in the RM test, mature adults outperformed young counterparts except for the young-enriched rats, which showed a progressive improvement in RM performance. At the neurochemical level, young EE rats showed higher hippocampal glutamate and GABA concentrations, and DA turnover in VS, which correlated with RM performance. Altogether, the behavioral and cognitive strategies underlying habituation learning and spatial memory seem to be qualitatively different between the two ages analyzed. These results challenge the assumption that mature adult animals are always worse in learning and memory tasks. However, young rats benefited more from the social and physical stimulation provided by the enrichment than mature adult counterparts. The latter effect was evident not just on behavior, but also on brain neurochemistry.

Individual differences in the forced swimming test and neurochemical kinetics in the rat brain.

Individual differences in the forced swimming test (FST) could be associated with differential temporal dynamics of gene expression and neurotransmitter activity. We tested juvenile male rats in the FST and classified the animals into those with low and high immobility according to the amount of immobility time recorded in FST. These groups and a control group which did not undergo the FST were sacrificed either 1, 6 or 24 h after the test. We analyzed the expression of the CRF, CRFR1, BDNF and TrkB in the prefrontal cortex, hippocampus and nucleus accumbens as well as norepinephrine, dopamine, serotonin, glutamate, GABA and glutamine in the hippocampus and nucleus accumbens. Animals with low immobility showed significant reductions of BDNF expression across time points in both the prefrontal cortex and the nucleus accumbens when compared with non-swim control. Moreover, rats with high immobility only showed a significant decrease of BDNF expression in the prefrontal cortex 6h after the FST. Regarding neurotransmitters, only accumbal dopamine turnover and hippocampal glutamate content showed an effect of individual differences (i.e. animals with low and high immobility), whereas nearly all parameters showed significant differences across time points. Correlational analyses suggest that immobility in the FST, probably reflecting despair, is related to prefrontal cortical BDNF and to the kinetics observed in several other neurochemical parameters. Taken together, our results suggest that individual differences observed in depression-like behavior can be associated not only with changes in the concentrations of key neurochemical factors but also with differential time courses of such factors.

Individual differences in the immobility behavior in juvenile and adult rats are associated with monoaminergic neurotransmission and with the expression of corticotropin-releasing factor receptor 1 in the nucleus accumbens.

The study of individual differences provides an important methodological approach to analyze the neurobehavioral spectrum of a given cohort in order to understand brain function and disease. Based on immobility time in the forced swimming test (FST) juvenile and adult rats were classified as subgroups with low and high immobility. Afterwards, we compared behavior, neurochemical parameters, and gene expression profiles in some brain areas of rats with low and high immobility only. No differences in the open field test (OFT) were observed between subgroups. Regarding neurochemistry, juvenile animals with low immobility showed higher accumbal dopamine turnover and lower hippocampal norepinephrine concentrations, whereas adult rats only differed for accumbal dopamine, although in an opposite direction from that observed in juveniles. Moreover, the expression of accumbal corticotrophin-releasing factor receptor 1 (CRFR1) was significantly different in animals with low and high immobility at both ages, with animals less immobile showing higher levels of CRFR1 mRNA levels. Taken together, our findings suggest that differences in monoaminergic neurotransmission and CRFR1 expression are associated with the coping strategy adopted by the animal and with the tendency to develop depression-related behaviors. Concerning monoaminergic neurotransmission such association is modulated by age, and such modulation could be related to the differential behavioral results observed between juvenile and adult rats.

Behavioral and neurochemical characterization of maternal care effects on juvenile Sprague-Dawley rats.

Maternal care represents a major constituent of early life environment and has the potential to modulate critical neurobehavioral responses to stress. The aim of the present study was to determine the effects of naturally occurring variations in maternal care on behavioral and neurochemical responses of juvenile Sprague-Dawley rats. A group of dams were classified based on their licking behavior in high and low licking-grooming mothers. Afterwards, the male offspring was tested in a series of behavioral tests: open field test (OFT), elevated plus maze (EPM) and forced swimming test (FST). Additionally, monoamine concentrations were determined post-mortem in three brain regions: hippocampus, ventral striatum and prefrontal cortex. Our findings suggest that maternal care variations have an effect on several anxiety-related behaviors in OFT and EPM but not in depression-like behaviors in FST. Such behavioral differences could be related to an increased DOPAC concentration and 5-HT turnover in prefrontal cortex. These evidences suggest that natural variations in maternal care modified some behavioral and neurochemical parameters related with anxiety and stress in this strain.

Maternal behavior as an early modulator of neurobehavioral offspring responses by Sprague-Dawley rats.

Maternal care plays an important role as an early modeler of neurodevelopment and brain function, and its effects remain until adulthood. Such modeling or programming has shown to influence the stress response and represents a key susceptibility factor in the development of mood disorders. In order to characterize such process which is still not clear, male offspring were classified in animals with low, medium and high licking/grooming (LG) according to the maternal behavior. Juvenile animals were subjected to the open field test (OFT) and the forced swimming test (FST), and offspring of low and high LG mothers were compared. Seven days after the FST, neurochemical and gene expression analyses were carried out in order to identify possible changes on relevant targets. Maternal care did determine locomotor behaviors in the OFT, supporting an anxiogenic effect of low maternal investment. This effect seems to be associated with the serotonergic systems in both nucleus accumbens (NAc) and hippocampus (HPC), since offspring of low LG mothers showed decreased 5-HT neurotransmission in those brain regions compared with animals of high LG mothers. Furthermore, TrkB expression was higher in offspring of high LG compared to the group of low LG mothers, supporting its influence as a mechanistic intermediate of such effect, at least in the NAc. Taken together, these findings strongly support the influence of differential maternal care on the neurodevelopment and responsivity of juvenile rats.

Validez y confiabilidad de tres escalas para evaluar conductas sociales en preescolares y escolares / Validity and reliability of three teachers’ ratings scales of socials be-haviors in preschoolers and scholars children

Estudiamos la validez y confiabilidad de tres escalas para evaluar conductas sociales niños y niñas costarricenses de preescolar y primer grado (n=262). Una de las escalas evalúa el comportamiento prosocial (ECPRO), otra evalúa la habilidad de explotar la experticia de los demás (EXHAD), y una más evalúa el comportamiento maquiavélico (EMach) en el ámbito escolar. Las escalas son completadas por docentes previamente capacitadas, de modo que el puntaje de cada niño o niña depende del criterio de su maestra respectiva. La estructura factorial de cada escala fue evaluada mediante un análisis de componentes principales. Según este análisis la ECPRO exhibió una estructura unidimensional caracterizada por un componente denominado “Disposición para Ayudar a los Otros”, la EXHAD mostró dos componentes principales denominados “Aprendizaje Social por Observación” y “Explotación de la Frutos de la Experticia de los Demás”, y la EMach reveló tres componentes: “Tácticas Maquiavélicas”, “Actitudes Ambivalentes hacia los Demás” y “Comprensión Social”. Las escalas arrojaron evidencia sobre una adecuada confiabilidad interna y validez de constructo. La ECPRO y la EMach evidenciaron validez discriminante entre sí. Además, estos hallazgos sugieren que el criterio de las maestras es una muy buena alternativa para evaluar este tipo de conductas sociales (AU)

The purpose of this study was to expose validity and reliability of three teacher’s ratings scales of socials behaviors in one sample (N=262) of preschoolers and scholars (grade one) Costa Ricans children. We design one scale of prosocial behavior (ECPRO) and other to evaluate the ability of exploiter the other’s expertise (EXHAD). Moreover we adapt one scale of machiavellian behavior (EMach). Teachers completed three scales for each participant. Factor structure was evaluated by principal components analysis. This analysis show that ECPRO is form by one component “Disposition for help others”, EXHAD is constitute by two components “Social Learning by Observation” and “Exploiting the Fruits of Other’s Expertise”; whereas EMach is constitute by three components “Machiavellian Tactics”, “Ambivalent Attitudes Toward the Others” and “Social Understanding”. The three teacher’s ratings scales show evidence of construct validity and internal reliability; furthermore ECPRO and EMach show discriminant validity. In addition these findings suggest that teachers are an excellent choice to evaluate this kind of socials behaviors (AU)

Interacciones entre el entendimiento de la falsa-creencia y el desarrollo de la habilidad verbal: Diferencias entre los sexos en edad preescolar / Interactions between false-belief understanding and verbal ability development: Sex differences in preschool children

En este artículo se analiza el desempeño de niños y niñas en la resolución de tareas de falsa-creencia y se explora la posible influencia del desarrollo de las habilidades verbales sobre las diferencias de rendimiento entre ambos sexos en dichas tareas. El trabajo incluye dos estudios: En el Estudio 1 se comparó el entendimiento de la falsa-creencia y la habilidad verbal de 17 niños y 17 niñas costarricenses de 5 años, con el entendimiento de la falsa-creencia y de la habilidad verbal de 17 niños y 17 niñas costarricenses de 6 años de edad. Para el Estudio 2, los mismos participantes del grupo de 5 años del Estudio 1 fueron reevaluados después de un período de 3 meses. En el Estudio 1, el grupo de niñas de 6 años evidenció un desempeño significativamente mayor que el grupo de niñas de 5 años, tanto en el índice de habilidad verbal como en el entendimiento de la falsa-creencia. En contraste, entre los niños de 5 y 6 años solo se encontró un incremento no significativo en los puntajes de ambas variables. Luego de reevaluar a los participantes de 5 años, el Estudio 2 confirmó estas diferencias entre ambos sexos y verificó que los incrementos entre ambas variables son mutuamente dependientes. Los hallazgos principales de ambos estudios señalan diferencias significativas en el desarrollo cognitivo de los preescolares según su sexo. La relevancia de los resultados se discute en el contexto del debate actual sobre las interacciones entre la habilidad verbal y la teoría de la mente durante la edad preescolar.

The purpose of this article is to analyze some developmental interactions between cognitive processes during the preschool period. In specific, we are interested in the interactions between verbal ability and false-belief understanding. The research explores the performance of boys and girls in the execution of false-belief tasks, and evaluates the possible influence of verbal ability development on the sex differences in the falsebelief scores. In recent times, the emphasis on the sex differences in this dimension of social cognition has been an important issue stemming from the results of current lines of research. The present work is divided in two studies. The Study 1 compares the false-belief understanding and verbal ability of 17 five-year-olds Costa Rican boys and 17 five-year-olds Costa Rican girls, with the false-belief understanding and verbal ability of 17 six-year-olds Costa Rican boys and 17 six-year-olds Costa Rican girls. The main interest of this first study is focused on the identification of interactions between the cognitive processes of the participants. Sub sequently, in Study 2, the same five-year-olds that participated in Study 1 were reevaluated through the same measures after a period of 3 months. The goal of this second study was to follow up the tendencies evidenced in the previous study, after a brief period of time. As an attempt to capture specific details in the development of these processes and given the recommendations of previous works, an interval of 3 months between measures was used here for the first time in the context of this line of research. All the participants were students from a public preschool in the capital city of Costa Rica and native speakers of the Spanish language. Additional inclusion criteria take into account the absence of developmental disorders and other antecedents of psychiatric / psychological intervention. The assessment of false- belief understanding was through a battery that includes four different false-belief tasks. This battery was conformed by 3 first order false-belief tasks, and one second order false-belief task. For the assessment of verbal ability, the study includes 4 subtests (Information, Arithmetic, Vocabulary, and Comprehension) from the WPPSI-III Verbal Ability Scale. The results of the Study 1 evidenced that the six-year-olds girls had significantly higher scores than the five-year-olds girls, both in verbal ability and in false-belief understanding. Interestingly, the improvements in both abilities were mutually dependent. In contrast, the scores at the same variables showed a small but not significant improvement between five and six-year-olds boys. In Study 2, our results confirm these sex differences through the reassessment of the same five-year-olds, and verify that the improvements in both abilities are mutually dependent. The main results of both studies highlights important sex differences in the cognitive development of preschool children. In both studies the false-belief understanding and verbal ability improve significantly in girls but not in boys. The implications of our data are discussed in the context of the actual debate about the interaction between verbal ability and theory of mind during the preschool years. The possible influences of different socialization processes associated with a particular gender are discussed, as well as other tentative mediating factors like the empathic abilities or the influence produced by the context of different daily play scenarios among boys and girls. Research limitations like the particular period of assessment between measures in the Study 2 or the necessity of more tasks for each construct are also discussed. Finally, tentative mechanisms that could account for our data are considered.

A high performance liquid chromatography method with electrochemical detection of gamma-aminobutyric acid, glutamate and glutamine in rat brain homogenates.

Determination of gamma-aminobutyric acid (GABA), glutamate (Glu) and glutamine (Gln) in animal models has been important to understand the normal function and clinical aspects of some neurological diseases. Quantification of these amino acid transmitters has conventionally been performed by using a high performance liquid chromatography (HPLC) system. This paper describes an improved HPLC method with electrochemical detection for glutamate, glutamine and GABA determination in brain homogenates. The protocol is based on a precolumn derivatization of amino acids with o-phthalaldehyde and sodium sulfite, a separation through a C18, 5 microm particle size column and an isocratic elution. Several modifications of previous works on methanol percentage, pH, temperature, flow rate and derivatization solution concentration were done to obtain a suitable protocol for amino acid quantification in brain homogenate samples. Total elution time is 35 min approximately. Technical requirements and laboratory expenses of this new protocol are minimal. This technique showed high linearity, repeatability and accuracy.

Diagnóstico molecular de la enfermedad de Huntington en Costa Rica / Molecular diagnosis of Huntington`s disease in Costa Rica

Justificación y objetivo. Este estudio representa un esfuerzo para establecer por primera vez en Costa Rica el diagnóstico molecular de la enfermedad de Huntington; esto favorecerá un mejor manejo clínico de los pacientes y podrá ser traducido en un incremento de la calidad de vida de las familias. Se pretende determinar el número de repeticiones CAG en personas con la enfermedad de Huntington y familiares mediante el diagnóstico molecular, con el fin de ofrecerles asesoramiento genético adecuado y oportuno. Métodos: El estudio se realizó en 7 pacientes con diagnóstico clínico de Huntington y 31 familiares en riesgo. Para determinar el número de repeticiones CAG se utilizó la reacción en cadena de polimerasa y la posterior electroforesis sobre geles de agarosa y poliacrilamida. Resultados: Se obtuvo el diagnóstico molecular de los 38 individuos. Se confirmó el diagnóstico clínico en las 7 personas afectadas, se encontraron 11 con la mutación que permanecían asintomáticas y 20 sin la mutación. Se observó una correlación negativa entre la edad de inicio y el número de repeticiones, así como inestabilidad intergeneracional, tanto vía materna como paterna. No hay diferencias en el número de repeticiones, según el sexo del progenitor transmisor. Conclusión: Los análisis moleculares mostraron un perfil de repeticiones similar al de otras poblaciones. Hemos identificado las primeras familias portadoras de enfermedad de Huntington en Costa Rica, permitiendo dar a los pacientes y su familia asesoramiento genético adecuado y oportuno basado en información confiable.

Un método simple para la recolección, extracción y medición de catecolaminas en orina de adultos mayores / A simple method to collect, extract and measure urinary catecholamines in elderly people

La medición de catecolaminas en orina ha sido utilizada tanto para diagnóstico como para la investigación. Este trabajo propone algunas modificaciones y condiciones estandarizadas para llevar a cabo la recolección de muestras de orina y la extracción y cuantificación de las catecolaminas utilizando cromatografía líquida de alto desempeño con detección electroquímica (HPLC-EC). Se probaron distintos métodos de preservación de la muestra durante la recolección, y se encontró que no es necesario utilizar ningún preservante o refrigerante para mantenerla estable. Se utilizó también la extracción en fase sólida (EFS) en la que, al modificar variables como la velocidad de elusión y la cantidad del eluyente final, se obtuvieron porcentajes de recuperación de 85,8% para dopamina, 88% para epinefrina y 96,9% para norepinefrina. En la medición por cromatografía, los coeficientes de variación fueron menores al 10% en la evaluación entre días y entre corridas; el error fue 2,5% en todos los casos. Se probó, además, que el método es lineal (r²Z0,9882; a<0,001) y que los valores obtenidos son comparables con resultados reportados previamente para adultos mayores, aunque el método y los cambios propuestos podrían ser utilizados también en otros grupos etarios.

Catecholamines in plasma and urine have been widely used for clinical diagnosis and research. The present paper proposes simple changes to collect, extract and quantify catecholamines among elderly people, and to obtain more accurate results using HPLC-EC. Refrigeration and acid were tested as preserving methods during urine collection. A pre-treatment with SPE was used to clean samples, and some variables were changed in order to improve recovery previous to chromatography analysis. No significant differences were found in sample catecholamines concentration using different preservation methods, or even in samples without refrigeration or acid during collection. Recovery obtained after changing some variables in SPE was 88.0% in epinephrine, 85.8% in dopamine and 96.9% in norepinephrine. VC was less than 10% between-days and between-run evaluation in all catecholamines, and error was 2.5%. Calibration curves were linear (r²Z0.9882; a<0.001) in matrixes employed. Values obtained in test samples were comparable with previous results reported in elderly people. The method and the changes proposed are useful to measure urinary catecholamines in elderly people. However, it is proposed that they could also be useful for other age groups, and not only for research but also for clinical purposes.

Factor analysis of Forced Swimming test, Sucrose Preference test and Open Field test on enriched, social and isolated reared rats.

Developmental and social factors are known to play a crucial role in the pathogenesis of affective disorders. Although it has been demonstrated that early life aversive experiences can be a risk factor in the development of human depression, most of the investigation in animals that try to model depression do not include postnatal manipulations. Since housing represents a fundamental ethological factor which modifies behavior and brain development, this study aimed to investigate the impact of different social and structural housing conditions on the development of a depressive-like syndrome in the behavioral despair paradigm and an anxiety-like syndrome in the unconditioned anxiety paradigm. The present study uses several multivariate analyses to study the impact of housing conditions in animal models of depression and anxiety. In this study, social isolation was able to reproduce the effects found in other animals models based on stress, suggesting that only 2 months of social isolation are enough to produce effects that can be useful as behavioral model of depression. Moreover, environmental enrichment showed an antidepressive and anxiolytic like effect in animal models of depression and anxiety. This effect, which has not been reported in earlier studies, suggests that stimulation during the first stages of growth might play a "protective" role on behavior and brain development.