A psychometric analysis of the Early Trauma Inventory-Short Form in Colombia: CTT and Rasch model.

BACKGROUND: Potential childhood traumatic experiences increase risk for mental and physical health disorders and their precise assessment can help to promote health prevention and promotion strategies for countries with limited data and measurement strategies like Colombia. OBJECTIVE: The goal of the present study is to strengthen evidence for the validity of scores from an adapted version of the Early Trauma Inventory self report-short form (ETI-SF) using Item Response Theory and by assessing factorial invariance across gender and education level. PARTICIPANTS AND SETTING: The study assessed a total of 1909 Colombian participants (66.16 % women, 32.16 % men, 1.68 % other gender; age range 18-72 years old). METHODS: Participants answered the ETI-SF via a web-based sampling strategy. RESULTS: The total scores of the scale showed good reliability coefficients (α = 0.81 and ω = 0.60). A specific analysis for the subscales showed good reliability for the emotional, physical, and sexual trauma subscales (αs and ωs >0.64), while general trauma showed lower than accepted reliability values (α =0.56 and ω = 0.37). Most of the individual items of the scale showed good calibration. The factorial invariance analysis suggests the possibility of some gender and educational differences. CONCLUSIONS: The study confirms particularly high rates of potential childhood traumatic experiences in Colombia and complement data for specific trauma types. Overall, the ETI-SF is confirmed as useful for Colombia, which highlights this scale as a good tool to use for public health assessment. Future research can continue the integration of diverse methods for estimating the quality of the scale.

Early developmental risks for tobacco addiction: A probabilistic epigenesis framework.

Considerable progress has been made in elucidating the relationships between early life psychobiological and environmental risk factors and the development of tobacco addiction. However, a comprehensive understanding of the heterogeneity in tobacco addiction phenotypes requires integrating research findings. The probabilistic epigenesis meta-theory offers a valuable framework for this integration, considering systemic, multilevel, developmental, and evolutionary perspectives. In this paper, we critically review relevant research on early developmental risks associated with tobacco addiction and highlight the integrative heuristic value of the probabilistic epigenesis framework for this research. For this, we propose a four-level systems approach as an initial step towards integration, analyzing complex interactions among different levels of influence. Additionally, we explore a coaction approach to examine key interactions between early risk factors. Moreover, we introduce developmental pathways to understand interindividual differences in tobacco addiction risk during development. This integrative approach holds promise for advancing our understanding of tobacco addiction etiology and informing potentially effective intervention strategies.

Stress effects on spatial memory retrieval and brain c-Fos expression pattern in adults are modulated by early nicotine exposure.

The cognitive effects of nicotine are linked to persistent modifications in extended neural systems that regulate cognitive and emotional processes, and these changes occur during development. Additionally, acute stress has modulatory effects on cognition that involve broad neural systems and can be influenced by prior environmental challenges. The effects of nicotine and stress may be interconnected, leading to modifications in a network of shared brain substrates. Here, we explored the interaction between nicotine and stress by evaluating the effects of acute stress exposure in spatial memory retrieval for animals pretreated with nicotine during adolescence or adulthood. Adolescent (35 days old) and adult (70 days old) male Wistar rats were treated for 21 days with one daily subcutaneous injection of nicotine 0.14 mg/ml (free base). 30 days after the last injection, rats were trained in the Barnes maze and tested 24 h later, half the rats were tested under regular conditions, and half of them were exposed to 1 h of restraining stress before the retrieval test, and brain samples were collected and c-Fos immunopositive cells were stained. Prolonged nicotine withdrawal or acute stress improved spatial memory retrieval. Acute stress in nicotine pretreated adults impaired spatial memory retrieval. Nicotine exposure during early adulthood resulted in long-lasting brain adaptations that amplified emotional responses to acute stress after prolonged drug withdrawal.

Adicción al tabaco y adolescencia: riesgos psicobiológicos / Psychobiological risks of tobacco during adolescence. A narrative review

Resumen La investigación moderna, tanto en humanos como preclínica, que utiliza modelos animales indica que fumar durante la edad adolescente resulta en cambios cerebrales y psicológicos a corto y largo plazo en el fumador, así como en un aumento significativo en los riesgos de desarrollar adicción al tabaco durante la vida. Por lo tanto, en la presente revisión narrativa se describirán y profundizarán los hallazgos investigativos modernos de la psicobiología de la adolescencia y los efectos del tabaco en el desarrollo, con un énfasis particular en la comprensión de los efectos psicológicos y cerebrales del consumo de tabaco durante la adolescencia, tanto a corto como a largo plazo. Se considerarán de manera detallada los avances investigativos sobre la psicobiología de la adolescencia y sus riesgos en las adicciones desde los aspectos: conductual, cognitivo, reactividad al estrés y psicobiología. Sobre esta base, se revisará la investigación sobre la psicobiología de la adolescencia y la evidencia de vulnerabilidad a la adicción durante esta etapa. Al final, se abordarán los efectos del tabaco en el cerebro y conducta durante el desarrollo adolescente y vida posterior, ya que se ha encontrado evidencia relacionada con alteraciones cerebrales crónicas en los sistemas colinérgicos y regiones cerebrales asociadas con la dependencia de la nicotina. Se espera que la revisión y divulgación de esta información en el idioma español sea de valor para la comprensión de los problemas de vulnerabilidad y predisposiciones a la adicción al tabaco en el contexto de Latinoamérica.

Abstract Tobacco use and its harmful health-related problems have become one of the largest modern preventable public health issues. Current research strongly suggests that smoking during adolescence enhances addictive smoking behaviors during life, which can be related to adolescence as a critical ontogenetic period characterized by behaviors that can increase the probability of risk-related behaviors such as sensation and novelty seeking. Adolescent development is also a period of maturation of frontal and subcortical neural systems, brain changes that underlie higher impulsivity tendencies to promote adequate learning and adaptations necessary to succeed the novel challenges of the adult life, but those changes also enhance vulnerabilities to the addictive effects of drugs. Consistent with this, tobacco use affects brain development processes which underlie long-term psychobiological alterations and the enhanced risks for tobacco addiction during adult life. Thus, the present review describes current psychobiological approaches to understand general addiction processes and tobacco addiction, highlighting the behavioral and neural short-term effects of tobacco use during adolescence and its long-term effects during adulthood. Current research has advanced on four aspects for the understanding of both the psychobiology of adolescent development and the effects of drugs of abuse during this time. The first aspect is behavioral, as adolescence is related to important changes on motivational and emotional behaviors such as sensation seeking. Other important behavioral changes are social approach, a higher variety of opportunity for personal choices, and development of personal independence. Research on a second aspect has focused on cognition. A review of research is presented showing enhanced abilities during adolescence development for reading, abstract and logical thinking, and novel problem solving. Stress reactivity is the third aspect of reviewed psychobiological mechanisms. The stress biological system undergoes important changes during adolescence, including changes on stress-related hormones and neural architecture. An important issue is that exposure to early and/or chronic stressful circumstances during adolescence could be related to higher risk to the start and maintenance of addiction states, as suggested by research assessing the disruptive effects of stress on psychobiological homeostatic processes needed to maintain stable biological and emotional regulation. The fourth aspect is psychobiology. In this section research is reviewed related to the development of monoaminergic brain circuits underlying motivation, novelty-seeking, impulsivity, and addiction processes. Using as model the previous review integration, the effects of nicotine are discussed, the essential addictive component of tobacco, on the neurochemical systems underlying tobacco addiction. Following this, important research is introduced that describes psychobiological changes during adolescence and evidence of vulnerability to addiction during this life stage. Then, current research on both short-term and long-term effects of tobacco or nicotine administration during adolescence on the brain, behavior, and cognition is introduced. The current research advances and discussions on the psychobiology of addictions in general, and tobacco addiction in particular, have been possible to a large extent from the use of animal models and preclinical research, since animal models have become crucial to identify learning, motivational, emotional, and cognitive mechanisms that underlie addictive processes, and making possible to perform experimental procedures to discover the functioning and participation of biological components. One example of such components is the cholinergic system, which is activated by nicotine and is part of the neurochemical machinery on different brain areas important for both tobacco addiction and adolescence development such as the dorsal striatum, amygdala, ventral tegmental area, nucleus accumbens, prefrontal cortex, and hippocampus. The present review and research divulgation written in Spanish are expected to clarify modern research on addiction and encourage current scientific education on the vulnerabilities and predispositions for tobacco abuse in Latin-American countries.

La administración de nicotina aguda retarda la extinción en automoldeamiento pavloviano: un estudio preliminar / Acute nicotine administration retards extinction from pavlovian autoshaping: A preliminary study

Resumen Introducción y objetivo: Los procesos de aprendizaje y motivación han sido centrales para la comprensión de los mecanismos que subyacen al tabaquismo. En particular, existe evidencia creciente sobre la importancia de valores motivacionales de incentivo para entender el inicio y mantenimiento del tabaquismo. El objetivo general de este experimento fue evaluar el papel de la nicotina aguda sobre el valor de incentivo de una recompensa natural, (comida) asociada con un estímulo ambiental, (palanca experimental). Método: Se utilizaron ratas Wistar. Se administró nicotina (0.4 mg/kg) de manera aguda en momentos específicos del entrenamiento, utilizando un procedimiento de diez sesiones de adquisición y cuatro sesiones extinción en una tarea pavloviana de automoldeamiento. El diseño experimental incluyó tres grupos, el grupo control de solución salina y grupos de nicotina durante la adquisición y la extinción. Resultados: Se encontró que la administración aguda de nicotina, de manera específica y en comparación con los otros dos grupos experimentales, resultó en un efecto de retardo durante la fase de extinción, y que una administración similar de nicotina no resultó en efectos observables durante el desempeño comportamental en adquisición. Conclusiones: Estos resultados apoyan el papel de la nicotina como fortalecedora del valor de incentivo de las claves ambientales durante la extinción para una tarea de automoldeamiento.

Abstract Introduction and goal: Learning and motivational processes have been central for a modern understanding of tobacco addiction. There is evidence that supports the importance of incentive motivational processes for the maintenance of tobacco addiction. The main goal of the present experiment was to evaluate the effects of acute nicotine on the incentive value of a natural reward, (food) paired with an environmental cue (pressing lever). Method: Wistar rats were used. Accute nicotine (0.4 mg/kg) was administered on key sessions, using a pavlovian autoshaping procedure involving ten acquisition and four extinction sessions. The experimental design included three groups, a saline administration control group and groups with specific nicotine administration during either acquisition or extinction. Results: We found that acute administration of nicotine, in contrast with saline only or previous nicotine administration during acquisition, had an enhancing effect on responding for the environmental cue during autoshaping extinction, but we did not find evidence that acute nicotine affected acquisition performance. Conclusion: Our results are consistent with a role of nicotine enhancing the incentive value of stimuli during extinction from a pavlovian autoshaping task.

Validation of the Early Trauma Inventory Self Report-Short Form and trauma prevalence in Colombia.

OBJECTIVE: Early traumatic experiences are related to profound and long-lasting negative effects on mental and physical health. Colombia has been involved in a war for the last six decades. Thus, the main objective was to adapt and validate the Early Trauma Inventory Self Report-Short Form in Colombia, as well as assess trauma prevalence in this country. METHOD: For this purpose, a total of 2,080 Colombians participated in this study (57.3% women and 42.4% men). Age ranged from 18 to 77 years old. They answered the 27-item version of the Early Trauma Inventory Self Report-Short Form and a sociodemographic evaluation tool. Web-based sampling was carried out between March 16 and March 30, 2020. RESULTS: Original four factor structure was successfully explored and confirmed here. Reliability indexes were good with alphas ranging from .69 to .93. Items properties were also adequate. Most of the assessed sample suffered trauma in their early stages (99.8%). Gender differences were analyzed observing significant differences. As expected, sexual abuse is more prevalent in women. CONCLUSIONS: To the best of our knowledge, the Colombian population has suffered the highest prevalence of early trauma experiences so far when compared to other countries. Emotional and social implications are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Fear Incubation Using an Extended Fear-Conditioning Protocol for Rats.

Emotional memory has been primarily studied with fear-conditioning paradigms. Fear conditioning is a form of learning through which individuals learn the relationships between aversive events and otherwise neutral stimuli. The most-widely utilized procedures for studying emotional memories entail fear conditioning in rats. In these tasks, the unconditioned stimulus (US) is a footshock presented once or several times across single or several sessions, and the conditioned response (CR) is freezing. In a version of these procedures, called cued fear conditioning, a tone (conditioned stimulus, CS) is paired with footshocks (US) during the training phase. During the first test, animals are exposed to the same context in which training took place, and freezing responses are tested in the absence of footshocks and tones (i.e., a context test). During the second test, freezing is measured when the context is changed (e.g., by manipulating the smell and walls of the experimental chamber) and the tone is presented in the absence of footshocks (i.e., a cue test). Most cued fear conditioning procedures entail few tone-shock pairings (e.g., 1-3 trials in a single session). There is a growing interest in less common versions involving an extensive number of pairings (i.e., overtraining) related to the long-lasting effect called fear incubation (i.e., fear responses increase over time without further exposure to aversive events or conditioned stimuli). Extended fear-conditioning tasks have been key to the understanding of fear incubation's behavioral and neurobiological aspects, including its relationship with other psychological phenomena (e.g., post-traumatic stress disorder). Here, we describe an extended fear-conditioning protocol that produces overtraining and fear incubation in rats. This protocol entails a single training session with 25 tone-shock pairings (i.e., overtraining) and a comparison of conditioned freezing responses during context and cue tests 48 h (short-term) and 6 weeks (long-term) after training.

¿Se recurre a la ciencia básica para la solución de problemas psicosociales en Latinoamérica? / Is basic science used to help solve psychosocial issues in Latin America?

Los países latinoamericanos enfrentan un conjunto complejo e idiosincrático de problemas sociales, entre los que se encuentra la búsqueda de soluciones relacionadas con la mejora de las condiciones de salud tanto física como mental de las personas. Dado que uno de los objetivos mismos de las ciencias y disciplinas psicológicas es precisamente la comprensión de los fenómenos, mecanismos y causas asociadas con la salud mental, los académicos y profesionales de la psicología latinoamericana se encuentran en una posición privilegiada para soportar los avances necesarios para la comprensión y solución de problemas psicosociales en Latinoamérica. Dado este potencial, una discusión clave para la psicología latinoamericana actual y futura se centra alrededor de las herramientas disciplinares a disposición de los psicólogos para la comprensión y solución de problemas psicosociales. En particular, el propósito del presente editorial es plantear una pregunta relacionada con las herramientas disciplinares de los psicólogos Latinoamérica nos contemporáneos y que podría ser fundamental para el desarrollo futuro de la psicología latinoamericana: ¿se utiliza suficientemente la ciencia básica para la solución de problemas psicosociales en Latinoamérica? Es clara la existencia de varias discusiones y modelos posibles para abordar el rango de interacciones entre ciencia básica y aplicada (Gutiérrez, 2011), pero también es claro que es imposible pensar en una disciplina psicológica, tanto históricamente como en la actualidad, que no esté informada de manera fundamental por la investigación en psicológica básica, neurociencias y ciencias de la medición (e. g., psicometría). Por lo tanto, una de las bases fundamentales del conocimiento necesario para solucionar problemas aplicados debe surgir de la interacción continua entre diversos conocimientos (básicos y aplicados) y métodos de investigación e intervención. Una implicación de esto se resume en que es mejor diseñar soluciones para problemas psicosociales utilizando conjuntamente el conocimiento de los principios y conocimientos de la ciencia básica, y no limitarse al conocimiento mismo de la práctica profesional.

Reward loss and addiction: Opportunities for cross-pollination.

Paradigms used to study the response to and consequences of exposure to reward loss have been underutilized in approaches to the psychobiology of substance use disorders. We propose here that bringing these two areas into contact will help expanding our understanding of both reward loss and addictive behavior, hence opening up opportunities for cross-pollination. This review focuses on two lines of research that point to parallels. First, several neurochemical systems involved in addiction are also involved in the modulation of the behavioral effects of reward loss, including opioid, GABA, and dopamine receptors. Second, there are extensive overlaps in the brain circuitry underlying both reward loss and addiction. Common components of this system include, at least, the amygdala, ventral and dorsal striatum, and various prefrontal cortex regions. Four emerging avenues of research that benefit from emphasis on the common ground between reward loss and addiction are reviewed, namely, the neural circuitry involved in reward devaluation, the influence of genetic and reward history on the behavioral vulnerability and resilience, the role of competing natural rewards, and emotional self-medication. An understanding of the role of reward loss in addiction will point to a deeper understanding of the initiation and maintenance of substance use disorders.

Impacto y calidad de la productividad académica de los investigadores en Colombia en neurociencia comportamental utilizando modelos animales / Impact and quality of academic production of Colombian researchers in Behavioral Neuroscience using animal models

La productividad científica colombiana es limitada considerando indicadores como el número de artículos publicados en revistas de alto impacto y el índice h. La ausencia de una línea de base y de metodologías de comparación de productividad dificulta trazar las expectativas de publicación provenientes de las instancias nacionales. El objetivo del presente estudio fue evaluar de manera comparativa aspectos relacionados con el impacto y la calidad de la productividad académica de los investigadores en neurociencia comportamental utilizando modelos animales en Colombia. Esto se hizo por medio de la descripción de la población total de investigadores activos en Colombia y la definición de una muestra comparativa de investigadores internacionales. Luego se determinaron en Scopus las métricas asociadas con producción de artículos científicos para cada investigador. Finalmente, se identificó el cuartil de las revistas en las que publicaron los investigadores para un subconjunto de artículos en el Scimago Journal & Country Rank (SJR; Scimago Lab). Se encontró que aunque los investigadores en Colombia presentan una tasa importante de publicación (0.9 artículos por año), cuando se hace un análisis comparativo están rezagados en todos los aspectos de productividad con relación a investigadores internacionales. Se espera que la metodología propuesta pueda extenderse a la evaluación del impacto y calidad de la productividad en temáticas específicas de otras áreas de investigación.

High-impact academic research productivity in Colombia is limited. The absence of baselines and methodologies for meaningful comparisons with other countries complicates productivity projections from academic institutions. The goal of the present study was to evaluate the impact and quality of the academic productivity of researchers working on behavioral neuroscience using animal models in Colombia. The total population of active researchers in Colombia was described, and a comparative international sample of researchers was determined. Subsequently, for each researcher, we analyzed metrics associated to scientific productivity using Scopus and the journal position in Scimago Journal & Country Rank (SJR; Scimago Lab) of a sample of published articles. We report that, although there is an important rate of productivity for researchers in Colombia (0.9 articles per year), all aspects related to productivity were notably lower when compared to a sample of international researchers. Analyses of academic productivity in other scientific areas in Colombia may be enriched by the proposed methodology.

Strain-dependent performance in nicotine-induced conditioned place preference.

Nicotine addiction is most likely a result of a combination of factors including the rewarding effects of the drug; these effects, however, might be influenced by genetic background. Using a conditioned place preference (CPP) paradigm and 8 inbred mouse strains, we conducted an initial examination of the role of genetic background in the rewarding effects of nicotine. Following habituation and initial place preference test, inbred strains (A/J, BALB/cByJ, C3H/HeJ, C57BL/6J, CBA/J, DBA/1J, DBA/2J, and 129/SvEv) were trained and tested in CPP for nicotine (0.35 mg/kg). Although several strains (C57BL/6J, CBA/J, and 129/SvEv) showed nicotine-induced CPP, 1 strain (DBA/1J) showed conditioned place aversion (CPA), and other strains (A/J, BALB/cByJ, C3H/HeJ, and DBA/2J) did not show CPP. Overall, these results indicate that nicotine's rewarding effects tested in CPP are differentially affected by the genetic background, and this trait has a relatively high heritability (42%-57%). This initial investigation lays the foundation for future studies examining the genetic substrates of nicotine reward.

Memory interfering effects of chlordiazepoxide on consummatory successive negative contrast.

Long-Evans rats downshifted from 32% to 4% sucrose solution exhibit lower consummatory behavior during downshift trials than rats exposed only to 4% sucrose. In Experiment 1, this effect, called consummatory successive negative contrast (cSNC), was attenuated by administration of the benzodiazepine anxiolytic chlordiazepoxide (CDP, 5mg/kg, ip) before the second downshift trial (Trial 12), but was not affected when CDP was administered before the first downshift trial (Trial 11). In Experiment 2, CDP administered after Trial 11 actually enhanced the cSNC effect on Trial 12. This posttrial effect of CDP was reduced by delayed administration (Experiment 3). This CDP effect was not present in the absence of incentive downshift (Experiments 4-5), or when animals were tested with the preshift incentive (Experiment 6) or after complete recovery from cSNC (Experiment 7). The posttrial CDP effect was observed after an 8-day interval between Trials 11 and 12 (Experiment 8) and when administered after Trial 12, rather than Trial 11 (Experiment 9). Experiment 10 extended the effect to Wistar rats. Because CDP is a memory interfering drug, it was hypothesized that its posttrial administration interferes with the consolidation of the memory of the downshifted incentive, thus prolonging the mismatch between expected (32% sucrose) and obtained (4% sucrose) incentives that leads to the cSNC effect.

Role of the ventrolateral orbital cortex and medial prefrontal cortex in incentive downshift situations.

The present research evaluated the role of two prefrontal cortex areas, the ventrolateral orbital cortex (VLO) and the medial prefrontal cortex (mPFC), on two situations involving incentive downshifts, consummatory successive negative contrast (cSNC) with sucrose solutions and Pavlovian autoshaping following continuous vs. partial reinforcement with food pellets. Animals received electrolytic lesions and then were tested on cSNC, autoshaping, open-field activity, and sucrose sensitivity. Lesions of the VLO reduced suppression of consummatory behavior after the incentive downshift, but only during the first downshift trial, and also eliminated the enhancement of anticipatory behavior during partial reinforcement, relative to continuous reinforcement, in autoshaping. There was no evidence of specific effects of mPFC lesions on incentive downshifts. Open-field activity was also reduced by VLO lesions, but only in the central area, whereas mPFC lesions had no observable effects on activity. Animals with mPFC lesions exhibited decreased consumption of the lowest sucrose concentration, whereas no effects were observed in animals with VLO lesions. These results suggest that the VLO may exert nonassociative (i.e., motivational, emotional) influences on behavior in situations involving incentive downshifts. No clear role on incentive downshift was revealed by mPFC lesions.

Effects of chronic low- and high-dose nicotine on cognitive flexibility in C57BL/6J mice.

The addictive nature of nicotine remains a global health problem. Despite the availability of treatments for smoking cessation, relapse to smoking after quit attempts still remains very high. Here, we evaluated the effects of chronic nicotine in male C57BL/6J mice in an operant cognitive flexibility task that required the animals to progress sequentially through multiple phases including visual discrimination, strategy shifting and response reversal. As frontostriatal circuits involving discrete regions of dorsal striatum contribute directly to decision-making processes, and BDNF modulates synaptic plasticity and learning, we also assessed the effects of nicotine on striatal BDNF expression. Osmotic minipumps containing either of the two doses of nicotine (low: 6.3 mg/kg/day; high: 18 mg/kg/day) or saline (control) were implanted for chronic delivery that lasted 4 weeks. Nicotine-treated mice exhibited greater response accuracy during visual discrimination. Neither dose of nicotine affected learning of new egocentric response strategy during set-shifting. However, higher but not lower dose of nicotine impaired reversal learning by increasing perseverative responding to the previously non-reinforced stimulus. Furthermore, this effect was associated with reduced BDNF levels in the dorsal striatum. Collectively, these findings suggest that higher relapse rates often observed in high nicotine-dependent smokers may be attributed to impairments in inhibitory control processes. Moreover, striatal BDNF may play a critical role in nicotine-induced alterations in cognitive flexibility.

Extinction of food-reinforced instrumental behavior in Japanese quail (Coturnix japonica).

Japanese quail (Coturnix japonica) were reinforced with food for traversing a runway for either 18 or 36 trials, administered at a rate of 1 trial per day. Then, all animals received 18 extinction trials. The latency to run from the start box to the goal box was the dependent variable. Extinction was significantly slower in animals that had received 50% partial reinforcement during acquisition, whether relative to a group matched in terms of acquisition trials (36 trials, twice the number of reinforced trials) or relative to a group matched in terms of reinforcements (18 trials). The latter group was also matched in terms of the temporal distribution of acquisition trials with the partial reinforcement group, being trained only on days when the partial group was scheduled to receive a reinforced trial. Thus, there was evidence of a spaced-trial partial reinforcement extinction effect. A comparison of groups receiving large versus small reward magnitudes yielded no evidence of the spaced-trial magnitude of reinforcement extinction effect, even though the large-reward group consumed approximately 3 times more food than the small-reward group. Moreover, a comparison of groups that received 36 versus 18 acquisition trials produced no evidence of the spaced-trial overtraining extinction effect, even though acquisition latencies were significantly lower for the group that received 36 acquisition trials. These results are discussed in relation to comparative research on learning phenomena involving incentive downshift manipulations.

Impairment of recovery from incentive downshift after lesions of the anterior cingulate cortex: emotional or cognitive deficits?

The anterior cinculate cortex (ACC) is known to be implicated in pain-fear and reward expectations. Animals were given electrolytic lesions of the ACC and then trained in the consummatory successive negative contrast (cSNC) situation. In cSNC, animals exposed to an incentive downshift from 32% to 4% sucrose exhibit less consummatory behavior than animals always exposed to 4% sucrose. The ACC lesion had no measurable effects on the consummatory performance of animals before the downshift (i.e., the lesion did not affect consumption of 32% vs. 4% sucrose); on the performance of unshifted, 4% sucrose animals; and on the first downshift trial. However, ACC animals exhibited a significant retardation of recovery from cSNC relative to downshifted shams. Within-trial analysis of consummatory behavior indicated that ACC lesions facilitated cSNC during both the initial and last 100 s of postshift trials after the first downshift experience, relative to sham controls. These results suggest that the ACC is part of the neural circuit normally involved in coping with the emotional response induced by the incentive downshift event by inducing learning of the new incentive conditions.

Mecanismos psicobiológicos y del desarrollo de la reactividad al estrés en roedores y Humanos / Psychobiological and developmental mechanisms for stress reactivity in rodents and humans

La investigación con modelos animales ha tenido un avance importante sobre el conocimiento de los mecanismos psicobiológicos que subyacen a las diferencias individuales que existen con referencia a la reactividad al estrés. La investigación animal también ha ayudado en la comprensión de los correlatos psicobiológicos de la reactividad al estrés en humanos, al sugerir mecanismos neuroquímicos particulares para la investigación y al producir modelos generales de funcionamiento psicológico aplicables en humanos. En este artículo se describen los elementos neuroquímicos básicos de la reactividad al estrés. Adicionalmente, se utiliza el modelo de epigénesis probabilística para incluir los elementos del desarrollo y genéticos que proveen el contexto necesario para la comprensión de las diferencias individuales en la reactividad al estrés. Finalmente, se describen algunos resultados y potenciales avances en la investigación de la psicobiología del trastorno de estrés postraumático en términos de los conceptos que han surgido desde la investigación animal.

Important research advances on the psychobiological mechanisms underlying individual differences for stress reactivity have resulted from research in animal models. Animal research has also shed light on the psychobiological correlates for stress reactivity in humans, providing candidate neurochemical mechanisms for human research and suggesting general theoretical models of psychological functioning across species. In this article, the basic neurochemical elements underlying stress reactivity are described. In addition, the probabilistic epigenesis theoretical model is used to introduce the necessary developmental and genetic context for the understanding of the psychobiology of individual differences in stress reactivity. Finally, some previous research and potential avenues of research in posttraumatic stress disorder are described using the concepts that emerged from animal research.

Posttrial d-cycloserine enhances the emotional memory of an incentive downshift event.

The present research was designed to determine whether an incentive downshift event induces an emotional memory that can be modulated by d-cycloserine (DCS), a partial agonist at the glycine site of N-methyl-d-aspartate receptor (NMDAR). DCS has been reported to have memory-enhancing properties in other training situations. Experiments 1 and 2 involved a consummatory successive negative contrast (cSNC) situation in which animals are exposed to an incentive downshift involving sucrose solutions of different concentrations. DCS administration (30 mg/kg, ip) immediately after the first 32-to-4% sucrose downshift trial (Experiment 1) retarded recovery of consummatory behavior, but immediately after the first 32-to-6% sucrose downshift trial (Experiment 2) did not affect recovery. There was no evidence that DCS affected consummatory behavior in the absence of an incentive downshift in a manner analogous to a conditioned taste aversion (Experiment 3). These results suggest that activation of NMDARs via the glycine modulatory site enhances the emotional memory triggered by exposure to an incentive downshift event.

Naloxone facilitates appetitive extinction and eliminates escape from frustration.

Two experiments tested the effects of opioid receptor blockage on behavior. In Experiment 1, rats reinforced for lever pressing with either sucrose or food pellets received treatment with saline, 2, and 10 mg/kg naloxone, i.p. (within-subject design). Naloxone 10 mg/kg increased response latency, but 2 mg/kg had no effect. When shifted to extinction (between-group design), naloxone (2 and 10 mg/kg) facilitated extinction relative to saline animals, after reinforcement with either sucrose or food pellets. In Experiment 2, after 10 sessions of access to 32% sucrose or an empty tube (between-group design), all rats were exposed to the empty tube while allowing them to jump over a barrier into a different compartment. Escape latencies were shorter for downshifted saline than for saline rats always given access to the empty tube. This escape-from-frustration effect was eliminated by naloxone (2 mg/kg, i.p.). Opioid blockage appears to reduce the value of alternative incentives.

Medición indirecta de la liberación de andrógenos y su relación con la conducta sexual en Coturnix japonica / Indirect measurement of androgen release and its relationship with sexual behavior in Coturnix japonica

El presente artículo tiene como objetivo describir y analizar las ventajas de la medición de la glándula cloacal de la codorniz japonesa macho como estrategia de evaluación indirecta de la producción de hormonas relacionadas con la conducta sexual de esta especie de ave. Primero, se hace una introducción al uso de aves como modelos experimentales en endocrinología conductual; luego, se presentan los argumentos a favor del uso de medidas indirectas de la producción hormonal. Se presenta investigación que muestra la relación de la medida del área y el volumen de la glándula cloacal, con otras medidas de producción de andrógenos y se presentan algunas investigaciones representativas que han hecho uso efectivo de esta medida.

In the present article we describe and analyze the advantages of measuringthe cloacal gland of male Japanese quail as a strategy to indirectly evaluate the production of hormones related to sexual behavior in this bird species.The use of animal models in general, and birds in particular, for the studyof the relationship between hormones and behavior is first introduced.Arguments for the advantage of using indirect measures of hormone productionare presented. Research that shows the correlation between area and volume of cloacal gland with other measures of androgen production is described, and some relevant research that has made use of indirect measures is presented.