Multilevel analysis of positive emotional induction: Which is the role of gender and valence on cognitive control processes?

How emotions are processed affects people's cognition and behavior. One of the most used measures to study the physiological component of emotions is heart rate (HR), where greater HR variation (range) implies greater emotional processing. Several investigations established the importance of gender modulation of these processes due to the different cultural treatment given to emotions among genders. However, very heterogeneous results are reported today, and few studies incorporated these parameters when investigating emotion modulation of cognitive processes according to individual factors. The present work consists of two studies. In a pilot study, 97 young adults, through the Self-Assessment Manikin (SAM), ranged the valence and arousal to select two positive and neutral videos. The second study analyses the role of gender and valence in the variation of subjective (SAM) and physiological (HR) indicators of emotional processing associated with performance in two cognitive tasks (Stroop and Tower of London) under two different emotional conditions. Participants were 60 adults, who were randomly assigned to positive or neutral video visualization, and their HR was registered. There was a tendency for women to have higher HR during positive videos than in neutral. While the subjective reports indicated variances in the appraisal of the videos, the heart rate did not exhibit differences across the experimental conditions. Few studies integrate emotional and cognitive components, and include physiological and subjective measures of emotional processing. These findings illustrate the importance of including various measures of emotional and cognitive processing.

Cognitive and emotional processing in tasks with emotional valence: Analysis of age and gender role on child development variations.

Cognitive control consists of high-level cognitive processes regulating thoughts and actions during goal-directed behavior and problem-solving. This study analyzes the performance of 4- to 8-year-old children in Stroop-like and ToL tasks using stimuli with different emotional valence. Significant differences were found in the performance in the congruent block of the Stroop-like task, where 5-year-old children presented a higher performance in the neutral condition. Also, a significant difference was only found in the incongruent block (with higher demand for inhibition), which indicates that girls performed better than boys in both task conditions. Variations in the Stroop-like task performance were found in preschoolers but not in older children, especially in girls than in boys. Specifically, these variations were found between age groups with at least two years of difference. No statistically significant differences were found in performance nor planning time in ToL between the age and gender groups in any of the task conditions. The findings highlight the need to analyze the interaction between cognitive and emotional processing, individual differences, and task demands.

Individual Differences in Emotional Appraisal during Development: Analysis of the Role of Age, Gender, and Appraisal Accuracy.

Emotional appraisal is the process by which different responses are generated from subjective assessments of different stimuli. Children and adults can react differently to the same stimulus. Emotional appraisal is crucial to define emotional processing and its consequent response rather than the properties of the stimulus itself. Age and gender modulate emotional appraisal during development. This study analyzed emotional appraisal in children aged 4 to 8-years-old. The children's emotional appraisal responses and the appraisal accuracy to images with positive, negative, and neutral valence be compared between the different age groups, and according to the gender of the participants. About the appraisal accuracy, the comparisons indicated significant differences for positive and negative images according to the age of the participants, with no differences in the appraisal accuracy of neutral images. Differences in appraisal accuracy for negative images were observed between the 4-years-old group compared to the 7- and 8-years-old group, as well as in 5-years-old participants compared to 7-years-old. Significant differences were found for the positive and negative images between girls and boys, but no differences were found for neutral images. Girls had more appraisals accuracy for positive and negative images. This work highlights the importance of analyzing individual differences associated with emotional processing at different stages of development. This interrogates research findings in which emotional appraisal is carried out considering the valence assigned by adults and highlights the need for a methodological approach that includes individual differences in the appraisal of stimuli used during development.

Individual and socioenvironmental differences in autobiographical emotional appraisal of preschoolers.

Emotions are essential processes for integrating events into autobiographical memory. Different children react differently to the same event. The process through which these different responses are generated from subjective evaluations of an event is called emotional appraisal. The main purpose of this study was to analyze the variations in the emotional appraisal of autobiographical events of 4- and 5-year-old children from homes with different socioenvironmental conditions. We compared preschoolers' emotional appraisal responses with those of their families. The emotional accuracy of the preschoolers was found to differ according to the different socioenvironmental conditions of their homes. Greater appraisal accuracy was observed in the favorable condition, and it was greater for emotional events than for neutral events. Appraisal accuracy also differed with age, with 5-year-olds showing greater appraisal accuracy than 4-year-olds. Therefore, the emotional appraisal of these events may also be affected by age and valence when attributing emotions to personal experiences.

Valoración emocional de imágenes y temperamento en preescolares: papel de la edad y la valencia / Emotional appraisal of images and temperament in preschoolers: Role of age and valence

Resumen La valoración es una etapa crucial del procesamiento emocional que prepara para la acción. Durante este proceso se generan distintas respuestas a partir de la evaluación de aspectos emocionales de los estímulos. Estas variaciones pueden deberse a la influencia de características individuales. La literatura señala al temperamento como uno de los factores asociados a las diferencias en la valoración emocional y el afrontamiento. Este trabajo analiza la relación entre la valoración emocional de estímulos visuales y características temperamentales obtenidas por medio del Cuestionario de Conducta Infantil (CBQ). Para esto, 198 preescolares de cuatro y cinco años valoraron 15 imágenes (negativas, neutras y positivas) y se analizaron estas valoraciones en función de las características temperamentales. Se encontró mayor cantidad de valoraciones negativas a los cuatro años que a los cinco (p = .056, η² parcial = .031), y de valoraciones positivas en el grupo con puntaje alto de esfuerzo de control en comparación con el de puntaje bajo (p = .020, η² parcial = .029). Esto sugiere una asociación entre la valoración emocional, la edad y el esfuerzo de control. Este resultado podría deberse a que las niñas y los niños estuvieran desviando su atención de los aspectos negativos de los estímulos.

Abstract Emotional appraisal is a crucial stage of emotional processing that prepares for action (coping). During this process different responses are generated from the evaluation of emotional aspects of the stimuli. These variations may be due to the influence of individual characteristics. The literature points to temperament as one of the factors associated with differences in emotional appraisal and coping. This paper analyzes the relationship between the emotional appraisal of visual stimuli and temperamental characteristics, obtained through the Children's Behavior Questionnaire (CBQ). For this purpose, 198 preschoolers aged 4 and 5 assigned of three possible emotional expressions to 15 images (negative, neutral and positive) and then compared the number of appraisals according to temperamental characteristics. Higher number of negative appraisals were found in the 4-year group compared to the 5-year group (p = .056, η² partial = .031), and of positive appraisals in the group with high effortful control score compared to the low score group (p = .020, η² partial = .029), suggesting an association between emotional assessment, age and effortful control. This result could be due to the fact that children were diverting they attention from the negative aspects of stimuli.

Role of Emotional Appraisal in Episodic Memory in a Sample of Argentinean Preschoolers.

Emotional processing and episodic memory are closely related throughout childhood development. With respect to emotional episodic memory, available evidence shows that the consolidation of information is accompanied by an arousal that generates longer duration and persistence of the memory representations. In the case of early stages of development (i.e., first 5 years), it is less clear how these associations emerge and are modulated by individual and environmental factors. In this study, 116 4- to 5-years old Argentinean children from different socio-environmental contexts (i.e., favorable or unfavorable living conditions at home), performed a task of visual emotional memory in which they observed a set of 15 images with variable emotional valences (negative, neutral, and positive). The child's task was to appraise each image using one of the following three possible valences: (a) drawings of faces with smiles (positive valence), (b) drawings of faces with tears and round mouth with edges down (negative valence), or (c) drawings of faces with horizontal mouth (neutral valence). Five years-old children exhibited greater accuracy appraisal. Individual differences in emotional accuracy appraisal allowed us to observe different performances in free recall of negative visual images. Accuracy appraisal did not vary between children with respect to gender, living conditions at home, or language ability. Seven to ten days after the emotional appraisal children were asked to tell the experimenter all the images they remembered (variables of interest: free recall of negative, positive, or neutral images). Results showed individual (age) differences. Specifically, 5-years-old children evoked more images than 4-years-old children. These findings contribute to the understanding of emotional memory in early developmental stages and raise the need to include emotional appraisal in the assessment of episodic memory.

Papel de las claves contextuales y dinámicas en el procesamiento emocional de niñas y niños preescolares / Role of contextual and dynamic keys in the emotional processing of preschoolers

Dentro del procesamiento emocional, la valoración emocional es el proceso mediante el cual se generan diferentes respuestas ante un mismo estímulo. El objetivo del presente trabajo es analizar la valoración de estímulos visuales, ampliando las claves contextuales y dinámicas mediante la utilización de videos con diferente contenido emocional en niñas y niños preescolares. Se realizó un estudio sincrónico de carácter exploratorio en el cual se evaluaron 35 niñas y niños de 5 años en una tarea de valoración emocional. La utilización de videos infantiles permitió la expresión de discrepancias en las respuestas de valoración, y la comparación entre la valoración que otorgaban las niñas y los niños, y la que tenían los videos. La variabilidad de las respuestas de valoración señala la importancia de considerar estas variaciones en el abordaje metodológico que se realice, ya que son un componente clave en el procesamiento emocional durante el desarrollo infantil

Within emotional processing, emotional appraisal is the process by which different responses to the same stimulus are generated. The aim of this paper is to analyze the emotional appraisal of visual stimuli, broadening the contextual and dynamic keys by using videos with different emotional content in preschool children. An exploratory synchronous study was conducted, in which 35 girls and boys aged 5 were evaluated for an emotional appraisal task. The use of children's videos allowed for the expression of discrepancies in the appraisal responses, and the comparison between the valuation of children and that of the videos. The variability of the appraisal responses points to the importance of considering these variations in the methodological approach to be carried out, as they are a key component in the emotional processing during childhood development

Papel de la motivación sobre la memoria emocional durante la etapa preescolar: un análisis preliminar. Papel de la motivación sobre la memoria emocional durante la etapa preescolar: un análisis preliminar / Role of motivation on emotional memory during preschooler stage: A preliminary analysis

La memoria emocional es una memoria de largo término con contenido emocional, positivo o negativo, donde los eventos emocionales se recuerdan mejor que los neutros. La motivación se define como un impulso para comportarse de una manera determinada, y puede dividirse en intrínseca (sin recompensas) y extrínseca (dirigida a metas). Debido a que los procesos cognitivos son favorecidos por la motivación, el objetivo de este trabajo fue analizar la interacción entre motivación y memoria de imágenes negativas, neutras y positivas, en dos grupos de niñas y niños de 5 años (recompensado y no recompensado). Los grupos no difirieron en el recuerdo de las imágenes de las tres valencias. Sólo en el grupo recompensado, las imágenes negativas fueron mayormente recordadas, lo cual indicaría que la recompensa luego de la tarea, favoreció la evocación posterior, y que este recuerdo fue diferencial en función del contenido emocional de las imágenes.

Emotional memory is defined as a long-term memory with emotional content, positive or negative, where emotional events are better remembered than neutral ones. Motivation is defined as an impulse to behave in a certain way, and can be divided into intrinsic (without rewards) and extrinsic (goal oriented). Cognitive processes are favored by motivation, so the objective of this work was to analyze the interaction between motivation and memory of images with different emotional valence in two groups of 5-year-old children (rewarded and not rewarded). The groups did not differ in the recall of any of the three valences. Only in the rewarding group did the negative images be remembered, which would indicate that the reward after the task favored the later evocation and that this memory was differential according to the emotional content of the images.

Desarrollo de las emociones en las niñas y los niños. Revisión de los principales factores moduladores / Development of emotions in children. A rewiew of the main modulating factors

La valoración emocional es un proceso central de la reacción emocional. Sin embargo, las investigaciones en niñas y niños se centran en el reconocimiento de las emociones. El objetivo de este trabajo es revisar las investigaciones recientes que analizaron los factores moduladores de la valoración emocional en niñas y niños preescolares. Se revisan estudios sobre el reconocimiento emocional y acerca de cómo éste aumenta su precisión a mayor edad y en posibles variaciones según la valencia de los estímulos (negativos, neutros y positivos). Se discute si el género podría ser un factor modulador de las reacciones emocionales, a partir de las diferencias en la valoración. Además, se sintetizan las investigaciones que analizaron la influencia del lenguaje, de la cultura y de la pobreza sobre las emociones. Debido a la escasez de estudios realizados en niñas y niños preescolares, este artículo sistematiza el conocimiento actual y propone claves sobre las que podrían orientarse investigaciones futuras.

Emotional appraisal is a central process of the emotional reaction. Nevertheless, research with children in this field is often focused on emotional recognition. The purpose of this work is to review the most recent researches and analyze the factors that modulate emotional appraisal in preschool children. Studies on emotional recognition in children and how it increases its accuracy according to the age are reviewed. Also, there are studies concerning possible variations according to the valence of the stimuli (negative, neutral and positive). Based on differences in the emotional appraisal, it is discussed if gender could be a modulating factor of emotional reactions. Furthermore, investigations that analyzed the influence of language, culture and poverty in emotions has been summarized. Due to the lack of studies in preschool children, this work aims to outline the current knowledge and put forward keys on which future research could be oriented.

Efectos de la edad sobre la valoración emocional durante la etapa preescolar / Effects of age on the emotional appraisal during preschool

La valoración emocional es el proceso por el cual se generan distintas respuestas emocionales a partir de las evaluaciones subjetivas del individuo sobre diferentes aspectos de los estímulos, tales como la relevancia personal de la situación y las opciones de afrontamiento, entre otras. Es decir, una misma situación percibida por dos personas distintas puede provocar reacciones emocionales diferentes. Estas variaciones pueden deberse a la existencia de diferencias individuales, sociales y culturales en la valoración de los estímulos. El estudio de la valoración emocional en las/os niñas/os añade dificultades relacionadas con el desarrollo de las emociones y con la categorización de las mismas durante la etapa preescolar. Una forma de explorar estas cuestiones es utilizar tareas con distintas valencias para evaluar el procesamiento de la información con diferente contenido emocional en niñas/os. Diversas investigaciones abordaron este tema, pero son escasos los trabajos que profundizaron el estudio en esta etapa del desarrollo cognitivo. El objetivo de este trabajo fue analizar la valoración de una muestra de niñas/os de 4 y 5 años en una tarea con estímulos visuales de diferente contenido emocional (negativo, neutro y positivo). En los resultados se consideró la cantidad de acuerdos entre las respuestas dadas por las/os niñas/os y la valencia relativa inherente a la tarea. Se observó un efecto de la edad sobre la valoración emocional, evidenciado a través de mayor acuerdo en las/os niñas/os de 5 años, en comparación con las/os de 4. Asimismo, las/os niñas/os de 5 años mostraron una tendencia a asociar con mayor acuerdo los estímulos emocionales (positivos y negativos), en comparación con los neutros. Estos resultados señalan la importancia de considerar la atribución de emociones como un proceso en desarrollo durante esta etapa infantil.

The emotional appraisal is the process through which different emotional responses are generated based on individual subjective evaluations of different aspects of stimuli, such as personal relevance of the situation and coping options, among others. Thus, a same situation perceived by two different persons can generate two different emotional appraisals. This difference would be due to cognitive, social and cultural variations in the assessment of the stimuli. The study of emotional appraisal in children adds difficulties related to the development of emotions and emotional categorization. One way to explore these issues is to use tasks with different valences to assess in-formation processing with different emotional content. Different studies addressed this but few approach the preschool period. The aim of this study was to analyze the assessment of different visual stimuli with negative, neutral and positive emotional contents in a sample of children aged 4 and 5 years. Results showed and effect of age in the number of agreements between the answers given by children and the relative valence inherent to the task. Specifically, 5-year-old children evidenced more agreements than 4-year-old. In addition, 5-year-old children were more likely to congruently associate the emotional images (valences positive and negative) in comparison to neutral ones. These results highlight the importance of considering the attribution of emotions as a developing process during the preschool period.

Childhood Poverty and Cognitive Development in Latin America in the 21st Century.

For at least eight decades, researchers have analyzed the association between childhood poverty and cognitive development in different societies worldwide, but few of such studies have been carried out in Latin America. The aim of the present paper is to systematically review the empirical studies that have analyzed the associations between poverty and cognitive development in children under 18 years of age from Latin American and Caribbean countries between 2000 and 2015. This analysis takes into consideration the country where the work was conducted, the experimental and analytical design, sample size and composition, cognitive and poverty paradigms implemented, levels of analysis, and the inclusion of mediation analyses. Through these, we identify common patterns in the negative impact of poverty that have been repeatedly verified in the literature in other continents; we also call attention to a set of issues regarding sample, design, paradigms, impact, and mediation analyses that should be considered in future studies in the region.

La memoria del niño en la etapa preescolar / The memory of the preschooler child

La memoria de los eventos pasados comienza a desarrollarse tempranamente en la vida y tiene grandes cambios durante la etapa preescolar. Este trabajo tiene el objetivo de analizar el desarrollo de la memoria de los niños desde el nacimiento hasta los cinco años, e identificar los factores que modulan los cambios que se producen sobre esta capacidad cognitiva en esta etapa. Para ello, se describirán los distintos paradigmas que se utilizan para evaluar los diferentes tipos de memoria en los niños. Además, se van a analizar las diferencias individuales, en relación a las emociones, el temperamento y el lenguaje, que regulan el desempeño de los niños durante estas tareas. Los hallazgos de la literatura señalan que la información obtenida desde un nivel de análisis conductual, cognitivo y ambiental, permite ahondar en los posibles mecanismos involucrados en la modulación de la memoria en los niños preescolares...

Memoria autobiográfica emocional: papel de las emociones sobre la evocación / Emotional autobiographical memory: role of emotions on the recall

En la evocación de las memorias, los eventos pasados que estuvieron acompañados por distintas emociones, se recuerdan más vívidamente y durante más tiempo. La memoria autobiográfica es un sistema humano único que integra experiencias pasadas dentro de una totalidad en la narrativa de la vida. Los recuerdos de eventos experimentados se integran en perspectiva, se los interpreta y evalúa alrededor de uno mismo y de los otros, creando así la historia personal. El objetivo de este trabajo es analizar la relación entre las emociones y la memoria de experiencias con contenido emocional. Para ello, se realizó un estudio en el cual se analizó si la valencia de los eventos modulaba la evocación de la memoria autobiográfica emocional. Los dos preliminares de este trabajo señalan que los participantes recordaron significativamente más eventos emocionales que no-emocionales, y que evocaron más eventos positivos, en comparación con los negativos y los neutros...

Evaluación y modulación de la memoria emocional: un estudio preliminar / Evaluation and modulation of emotional memory: a preliminary study

El objetivo de este trabajo fue evaluar la memoria de imágenes con diferente contenido emocional, y analizar si la realización de una tarea, con distintos niveles de complejidad, modulaba el recuerdo posterior de los participantes. Para ello 64 estudiantes observaron 24 imágenes emocionales y 24 neutras. Inmediatamente después, realizaban una tarea, que consistía en la resolución de operaciones matemáticas con distinto grado de dificultad. Una semana más tarde se evaluó a los participantes en una prueba de recuerdo libre. Como resultado se observó que las imágenes con contenido emocional se recordaron significativamente más que las neutras. La realización de la tarea no afectó la consolidación de la información acerca de las imágenes. Sin embargo, al igual que en la literatura, se encontró que el contenido emocional de las fotografías actuó como un neuromodulador facilitando la memoria de las imágenes emocionales, en comparación con las neutras.

Evaluación y modulación de la memoria emocional: un estudio preliminar / Evaluation and modulation of emotional memory: a preliminary study

El objetivo de este trabajo fue evaluar la memoria de imágenes con diferente contenido emocional, y analizar si la realización de una tarea, con distintos niveles de complejidad, modulaba el recuerdo posterior de los participantes. Para ello 64 estudiantes observaron 24 imágenes emocionales y 24 neutras. Inmediatamente después, realizaban una tarea, que consistía en la resolución de operaciones matemáticas con distinto grado de dificultad. Una semana más tarde se evaluó a los participantes en una prueba de recuerdo libre. Como resultado se observó que las imágenes con contenido emocional se recordaron significativamente más que las neutras. La realización de la tarea no afectó la consolidación de la información acerca de las imágenes. Sin embargo, al igual que en la literatura, se encontró que el contenido emocional de las fotografías actuó como un neuromodulador facilitando la memoria de las imágenes emocionales, en comparación con las neutras.(AU)

Modulación de la memoria emocional: una revisión de los principales factores que afectan los recuerdos / Modulation of emotional memory: a revision of the main factors which influence memories

Las emociones están íntimamente vinculadas con la memoria. Numerosas investigaciones señalan que los eventos con contenido emocional (positivos o negativos) se recuerdan en mayor medida que los neutros. En este sentido, la memoria emocional es el resultado del almacenamiento de la información que estuvo acompañada por factores alertadores a través de los cuales se fijó con más facilidad. De acuerdo con esto, el objetivo del presente trabajo es realizar una revisión de los principales factores que modulan la consolidación de la memoria emocional en humanos. Específicamente, se va a analizar cómo influyen las emociones y el estado de alerta que se produce en una situación de estrés sobre la memoria. Además se analizan los mecanismos neurobiológicos involucrados en la consolidación de los recuerdos de situaciones emocionalmente significativas.

Emotions are closely linked to memory. Numerous studies indicate that (both positive and negative) emotional events are remembered more than neutral ones. Emotional memory is the result of storing the information that was accompanied by stressful factors through which the information is more easily fixed. Based on this background, the aim of this work is to review the main factors which modulate emotional memory consolidation in humans. Specifically, this paper seeks to analyze the influence of emotions and the alert state that a stressful situation produces on memory, as well as the neurobiological mechanisms involved in memories of emotionally significant situations.

Effect of Neonatal Clomipramine Treatment on consummatory Successive Negative Contrast

La administración neonatal de clomipramina (CLI) produce alteraciones fisiológicas, neuroendocrinas y comportamentales en las ratas adultas, que son similares a las observadas en los modelos animales de depresión. En el Contraste Sucesivo Negativo consumatorio (CSNc), las ratas que recibieron una solución de sacarosa al 32%, consumen menos de una solución de sacarosa al 4%, que los animales que siempre recibieron la solución 4%. Este modelo de devaluación del incentivo produce en los animales una reacción emocional similar al miedo y la ansiedad. En el presente trabajo, estudiamos si el tratamiento neonatal con CLI altera la respuesta de CSNc en ratas adultas. Los hallazgos del presente trabajo sugieren que el tratamiento neonatal con un antidepresivo podría generar un aumento en la tolerancia a la frustración en animales adultos. Los animales a los que se les administró neonatalmente CLI presentaron una recuperación más rápida en el CSNc, que los animales controles sin tratamiento neonatal. Este resultado puede explicarse por una alteración del eje Hipotálamo-Pituitario-Adrenal (HPA), por un deterioro del sistema serotoninérgico, por la formación de una baja expectativa durante la fase de pre-cambio, o por una combinación de estos factores(AU)

Neonatal administration of clomipramine (CLI) produces physiological, neuroendocrinal and behavioral abnormalities in rats when they reach adulthood, which are similar to those observed in animal models of depression. In consummatory successive negative contrast (cSNC), rats that have had experience drinking 32% sucrose solution drink significantly less 4% sucrose solution than rats that have drunk only 4% solution. It triggers an aversive-emotional reaction similar to fear or anxiety. We studied whether neonatal treatment with CLI alters the cSNC’s response in adult rats. The findings of the present work suggest that the neonatal treatment with an antidepressive could generate an increase tolerance to frustration in adult animals. CLI rats showed a faster recovery from the cSNC than control animals, which may be explained by an alteration of the Hypothalamic- Pituitary-Adrenal axis (HPA), a serotonergic system deficit, a low expectative formation during pre-shift phase, or a combination of all these factors(AU)

Effects of testosterone administration and gonadectomy on incentive downshift and open field activity in rats.

Previous research showed that the effects of incentive downshift in male rats are attenuated by a pretrial opportunity to ejaculate. Because ejaculation raises testosterone (T) levels and has anxiolytic-like effects in male rats, the present experiments were designed to assess the role of T and gonadectomy (GDX) on two situations involving incentive downshift. In consummatory successive negative contrast, a downshift from 32% to 4% sucrose leads to consummatory suppression. T alleviates such suppression (Experiment 1), but GDX does not affect it (Experiment 3). In consummatory extinction, animals are downshifted from 32% sucrose to an empty sipper tube. T enhances consummatory extinction (Experiment 2), but GDX does not affect it (Experiment 4). In agreement with published results, T increases (Experiment 2) and GDX reduces (Experiment 4) activity in the central area of an open field, thus behaviorally validating these manipulations. The results are discussed in terms of the anxiolytic-like properties of androgen hormones.

Effects of pretraining treatment with testosterone on successive and anticipatory negative contrast.

Previous research indicated that the suppression of consummatory behavior that follows incentive downshift in male rats is attenuated by testosterone (T) administration during training. The present experiments were designed to assess the role of pretraining T administration on two incentive contrast situations in consummatory behavior: successive negative contrast (cSNC) and anticipatory negative contrast (cANC). In cSNC (Experiment 1), a downshift from 32% to 4% sucrose leads to behavioral suppression relative to an unshifted, 4% sucrose condition (the cSNC effect). Pretraining T administration enhanced consummatory behavior directed at 4% sucrose, without affecting behavior directed at 32% sucrose. This effect obscured a reduction in the cSNC effect by the T treatment that was only detected when a proportional measure of behavior was used. In cANC (Experiment 2), groups received access to two bottles per day separated by a short midtrial interval. Consumption of 4% sucrose is suppressed when the second bottle offers 32% sucrose, relative to 4% sucrose (the cANC effect). Pretraining T did not affect the cANC effect, known to be insensitive to treatment with anxiolytics. These results suggest an anxiolytic-like effect of testosterone in adjustment to incentive downshifts.

Neonatal treatment with clomipramine and depression: A review of behavioral and physiological findings

Many times in science, the discovery of a treatment that has certain effect happens accidentally while the scientists are investigating another phenomenon. This is the case of the discovery of a possible animal model of depression by the administration of clomipramine (CLI) during neonatal days. Adult animals exposed to CLI in neonatal days showed alterations in REM sleep (for example, the decrease of REM latency); lower weight, disruptions in locomotor activity (the increase in activity depend on the dark / light phase in which the test starts, when the animals were tested in the light phase they found increase in activity, but no changes were observed when the animals were tested in the dark phase); less intracraneal self-stimulation, lower saccharin and sucrose consumption, less suppression of the consummatory behavior, sexual alterations in males (for example, expressed as a lower number of mounts and ejaculations; no alterations were found in the activity of the Hypothalamic - Pituitary - Gonadal axis and the level of testosterone was normal), higher alcohol consumption, disruptions in the agonistic response (CLI - treated animals were significantly less aggressive than control groups) and in learning (in the passive avoidance task and 8 radial arm maze) compared to untreated animals (rats that received vehicle during neonatal days). Several of these abnormalities could be reversed with those treatments that are effective for treating depression in humans (antidepressive drugs, nicotine and REM sleep deprivation treatment). These results were obtained in male rats of different strains and in hamsters, and at different months, the majority of them at 3-4 months, and some of them after the sixth, this could be because some changes were caused with the decrement in the age of the animals, although further research is needed to elucidate this issue. Neuroendocrinal alterations analogous to those found in human depression were also discovered in CLI - treated rats, although the data is contradictory. These include Hypothalamic - Pituitary - Adrenal axis alterations; while it is true that some experimental results found that CLI - treated rats have a higher basal level of corticosterone than controls, others found that not only do they differ in basal level, also during the stress situation; circulating corticosterone increases less and returns more rapidly to basal levels than control groups. For this reason, we can conclude that if alterations in the HPA axis indeed exist in CLI - treated animals, it is still unclear in which way the deregulation is manifested. Other results support the hypothesis that alterations found in CLI - treated animals are due to alterations in serotoninergic transmission during a critical period of development, such as the neonatal stage; more specifically, a reduction in the hypothalamic concentration of serotonin, like a decrease in the neuronal firing in the dorsal raphe nucleus. An increase in cholinergic activity was also found, although the data in this field is not as vast as that found in relation to the neurotransmission of serotonin. All of these results suggest that rats treated with CLI during neonatal days present alterations in adulthood analogous to human depression, however other findings indicate that is not yet a valid model. Further research is needed, and we have to be cautious with the conclusions because there is some evidence suggesting that this is a promising model but other does not support its validity. If a model like the neonatal administration of CLI achieves the reproduction of some symptoms, neurophysiological and behavioral alterations of depression, the advantages are invaluable. In this sense, neonatal treatment with CLI is a very promising animal model for the study of depression.

El presente trabajo describe los principales resultados acerca de un nuevo y probable modelo animal de depresión. Este modelo se basa, paradójicamente, en la administración de un antidepresivo, clomipramina, a ratas neonatas. Cuando los animales alcanzan la adultez, muestran alteraciones comportamentales que pueden ser interpretadas como depresivas, como hiperactividad, descenso en la búsqueda de placer, anormalidades en el sueño, entre otras. Se analizan los posibles mecanismos neurofisiológicos y neuroendocrinos involucrados. A pesar de las limitaciones que ofrece un modelo animal, es importante cómo logra reproducir algunos síntomas hallados en la depresión y debido a esto las ventajas del mismo son invaluables. Además, pueden estudiarse los mecanismos cerebrales implicados en la patogénesis y tratamiento del trastorno que por razones éticas son impensables de llevar a cabo en humanos. Por ello, se considera de gran valor el estudio realizado con el modelo de clomipramina con la perspectiva de que se siga trabajando en la validación del mismo.