Intermittent fasting enhances long-term memory consolidation, adult hippocampal neurogenesis, and expression of longevity gene Klotho.

Daily calorie restriction (CR) and intermittent fasting (IF) enhance longevity and cognition but the effects and mechanisms that differentiate these two paradigms are unknown. We examined whether IF in the form of every-other-day feeding enhances cognition and adult hippocampal neurogenesis (AHN) when compared to a matched 10% daily CR intake and ad libitum conditions. After 3 months under IF, female C57BL6 mice exhibited improved long-term memory retention. IF increased the number of BrdU-labeled cells and neuroblasts in the hippocampus, and microarray analysis revealed that the longevity gene Klotho (Kl) was upregulated in the hippocampus by IF only. Furthermore, we found that downregulating Kl in human hippocampal progenitor cells led to decreased neurogenesis, whereas Kl overexpression increased neurogenesis. Finally, histological analysis of Kl knockout mice brains revealed that Kl is required for AHN, particularly in the dorsal hippocampus. These data suggest that IF is superior to 10% CR in enhancing memory and identifies Kl as a novel candidate molecule that regulates the effects of IF on cognition likely via AHN enhancement.

White Bear Suppression Inventory: translation and cross-cultural adaptation to Brazilian Portuguese.

Introduction Intrusive thoughts may cause a significant level of distress, since some individuals evaluate the content of those thoughts as aversive. Suppression of intrusive thoughts is one of the strategies adopted by these individuals, which increases the level of distress. Suppression of thoughts may be present as one of the factors that maintain different psychological disorders. Objective To describe the translation and adaptation into Brazilian Portuguese of the White Bear Suppression Inventory (WBSI), which measures thought suppression. Methods Three translations and back-translations were conducted by independent evaluators. Semantic equivalence was assessed and the three versions were evaluated to produce a synthesized version. Comments from participants on the preliminary version of the questionnaire were examined. Results We developed a preliminary Brazilian Portuguese version of the WBSI. It was found that most participants understood the descriptions of cognitions given in the translated questionnaire. Conclusion The use of three different versions of translations and back-translations, discussion of the synthetic version and interaction with the target population have conferred viability to the process of semantic equivalence of the Brazilian Portuguese final version of the WBSI.

White Bear Suppression Inventory: translation and cross-cultural adaptation to Brazilian Portuguese / White Bear Suppression Inventory: tradução e adaptação transcultural para a língua portuguesa do Brasil

Abstract Introduction Intrusive thoughts may cause a significant level of distress, since some individuals evaluate the content of those thoughts as aversive. Suppression of intrusive thoughts is one of the strategies adopted by these individuals, which increases the level of distress. Suppression of thoughts may be present as one of the factors that maintain different psychological disorders. Objective To describe the translation and adaptation into Brazilian Portuguese of the White Bear Suppression Inventory (WBSI), which measures thought suppression. Methods Three translations and back-translations were conducted by independent evaluators. Semantic equivalence was assessed and the three versions were evaluated to produce a synthesized version. Comments from participants on the preliminary version of the questionnaire were examined. Results We developed a preliminary Brazilian Portuguese version of the WBSI. It was found that most participants understood the descriptions of cognitions given in the translated questionnaire. Conclusion The use of three different versions of translations and back-translations, discussion of the synthetic version and interaction with the target population have conferred viability to the process of semantic equivalence of the Brazilian Portuguese final version of the WBSI.

Resumo Introdução Pensamentos intrusivos podem causar um nível significativo de desconforto, uma vez que alguns indivíduos avaliam o conteúdo desses pensamentos como aversivos. A supressão dos pensamentos intrusivos é uma das estratégias adotadas por esses indivíduos, resultando no aumento do nível de desconforto. Supressão de pensamentos pode estar presente como um dos fatores de manutenção de diferentes transtornos psicológicos. Objetivos Descrever a tradução e adaptação para o português brasileiro do White Bear Suppression Inventory (WBSI), que avalia a supressão de pensamentos. Métodos Três traduções e retrotraduções foram conduzidas por avaliadores independentes. A equivalência semântica foi analisada e as três versões foram avaliadas para produzir uma versão preliminar. Os comentários dos participantes sobre a versão preliminar do questionário foram examinados. Resultados Foi desenvolvida uma versão final em português brasileiro do WBSI. Verificou-se que a maioria dos participantes entendeu as descrições das cognições apresentadas no questionário traduzido. Conclusão O uso de três versões diferentes de traduções e retrotraduções, discussão da versão preliminar e interação com a população-alvo conferiu viabilidade ao processo de equivalência semântica da versão final brasileira da WBSI.

Adaptation of a cognitive-behavioral protocol for generalized anxiety disorder patientswith low educational attainment / Adaptação de um protocolo cognitivo comportamental para pacientes com transtorno de ansiedade generalizada com baixo nível educacional / Adaptación de un protocolo cognitivo-conductual de trastornos de ansiedad generalizada para pacientes con bajo nivel educativo

This article reports the experience of treating low-income patients with a primary diagnosis of generalized anxiety disorder (GAD) in a public hospital in Rio de Janeiro, Brazil. At the start of the project for outpatient treatment, which included the application of a cognitive model for GAD treatment, we observed that the majority of patients presented low educational level, which made it hard for them to understand key aspects of the cognitive-behavioral based treatment offered. Therefore, important adaptations to the treatment protocol were made necessary, including the way techniques were presented and applied, the therapeutic approach used, and even the duration of sessions. Since variations of cognitive therapy are increasingly being applied in hospital outpatient clinics in countries worldwide, the objective of this article is to present the adaptations performed and promote a discussion on the possible solutions for the difficulties faced in applying clinical psychology practice among patients with low educational and socioeconomic levels. This is a clinical study presenting an illustrative case, where adaptations to the treatment protocol were essential for the positive outcome of the case. It is concluded that, with the scope of treatment in mind, the therapist must be attentive to the client's demands and particularities in order to achieve therapeutic success.(AU)

Este artigo relata a experiência de tratamento de pacientes de baixa renda com diagnóstico primário de transtorno de ansiedade generalizada (TAG) em hospital público no Rio de Janeiro, Brasil. A ideia inicial do projeto era tratamento ambulatorial, com aplicação de um modelo cognitivo para o tratamento de TAG; porém, observamos que a maioria dos pacientes apresentou baixo nível educacional, o que tornava difícil sua compreensão dos principais aspectos do tratamento cognitivo-comportamental oferecido. Assim, foram feitas adaptações no protocolo de tratamento, incluindo a forma como as técnicas foram apresentadas e aplicadas, a abordagem terapêutica utilizada e a duração das sessões. Considerando que variações de terapias cognitivas são cada vez mais aplicadas em ambulatórios hospitalares em todo o mundo, o objetivo deste artigo é apresentar as adaptações realizadas e discutir possíveis soluções para as dificuldades enfrentadas na prática clínica com pacientes com baixo nível educacional e socioeconômico. Trata-se de um estudo clínico, com apresentação de um caso ilustrativo. Os resultados obtidos foram positivos e mostraram que as adaptações no protocolo foram essenciais para o sucesso terapêutico. Conclui-se que, tendo em mente o escopo do tratamento, o terapeuta deve estar atento às demandas e particularidades do cliente a fim de obter sucesso terapêutico.(AU)

Este artículo reporta la experiencia del tratamiento de pacientes de bajos recursos con diagnóstico primario de Trastorno de Ansiedad Generalizada (TAG) en hospitales públicos de Rio de Janeiro, Brasil. La idea original era el tratamiento ambulatorio con aplicación de un modelo cognitivo para el TAG. No obstante, el bajo nivel educativo presentado por la mayoría de los pacientes hace que les resulte difícil la comprensión de los principales aspectos del tratamiento cognitivo-conductual ofrecido. Adaptaciones fueron entonces realizadas en el protocolo de tratamiento, incluyendo cómo las técnicas fueron introducidas y aplicadas, el enfoque terapéutico utilizado y la duración de las sesiones. Dado que variantes de la terapia cognitiva son cada vez más aplicadas en la atención ambulatoria hospitalaria de todo el mundo, el objetivo de este artículo es presentar las adaptaciones realizadas y analizar posibles soluciones a las dificultades encontradas en la práctica de la psicología clínica con pacientes con bajo nivel educativo y socioeconómico, a partir de un caso ilustrativo. Los resultados obtenidos, positivos, indican que las adaptaciones realizadas fueron fundamentales para el éxito de la terapia. Podemos concluir que el terapeuta debe estar atento a las demandas y particularidad del cliente a fin de que la terapia sea exitosa.(AU)

Adaptation of a cognitive-behavioral protocol for generalized anxiety disorder patientswith low educational attainment / Adaptação de um protocolo cognitivo comportamental para pacientes com transtorno de ansiedade generalizada com baixo nível educacional / Adaptación de un protocolo cognitivo-conductual de trastornos de ansiedad generalizada para pacientes con bajo nivel educativo

This article reports the experience of treating low-income patients with a primary diagnosis of generalized anxiety disorder (GAD) in a public hospital in Rio de Janeiro, Brazil. At the start of the project for outpatient treatment, which included the application of a cognitive model for GAD treatment, we observed that the majority of patients presented low educational level, which made it hard for them to understand key aspects of the cognitive-behavioral based treatment offered. Therefore, important adaptations to the treatment protocol were made necessary, including the way techniques were presented and applied, the therapeutic approach used, and even the duration of sessions. Since variations of cognitive therapy are increasingly being applied in hospital outpatient clinics in countries worldwide, the objective of this article is to present the adaptations performed and promote a discussion on the possible solutions for the difficulties faced in applying clinical psychology practice among patients with low educational and socioeconomic levels. This is a clinical study presenting an illustrative case, where adaptations to the treatment protocol were essential for the positive outcome of the case. It is concluded that, with the scope of treatment in mind, the therapist must be attentive to the client's demands and particularities in order to achieve therapeutic success.

Este artigo relata a experiência de tratamento de pacientes de baixa renda com diagnóstico primário de transtorno de ansiedade generalizada (TAG) em hospital público no Rio de Janeiro, Brasil. A ideia inicial do projeto era tratamento ambulatorial, com aplicação de um modelo cognitivo para o tratamento de TAG; porém, observamos que a maioria dos pacientes apresentou baixo nível educacional, o que tornava difícil sua compreensão dos principais aspectos do tratamento cognitivo-comportamental oferecido. Assim, foram feitas adaptações no protocolo de tratamento, incluindo a forma como as técnicas foram apresentadas e aplicadas, a abordagem terapêutica utilizada e a duração das sessões. Considerando que variações de terapias cognitivas são cada vez mais aplicadas em ambulatórios hospitalares em todo o mundo, o objetivo deste artigo é apresentar as adaptações realizadas e discutir possíveis soluções para as dificuldades enfrentadas na prática clínica com pacientes com baixo nível educacional e socioeconômico. Trata-se de um estudo clínico, com apresentação de um caso ilustrativo. Os resultados obtidos foram positivos e mostraram que as adaptações no protocolo foram essenciais para o sucesso terapêutico. Conclui-se que, tendo em mente o escopo do tratamento, o terapeuta deve estar atento às demandas e particularidades do cliente a fim de obter sucesso terapêutico.

Este artículo reporta la experiencia del tratamiento de pacientes de bajos recursos con diagnóstico primario de Trastorno de Ansiedad Generalizada (TAG) en hospitales públicos de Rio de Janeiro, Brasil. La idea original era el tratamiento ambulatorio con aplicación de un modelo cognitivo para el TAG. No obstante, el bajo nivel educativo presentado por la mayoría de los pacientes hace que les resulte difícil la comprensión de los principales aspectos del tratamiento cognitivo-conductual ofrecido. Adaptaciones fueron entonces realizadas en el protocolo de tratamiento, incluyendo cómo las técnicas fueron introducidas y aplicadas, el enfoque terapéutico utilizado y la duración de las sesiones. Dado que variantes de la terapia cognitiva son cada vez más aplicadas en la atención ambulatoria hospitalaria de todo el mundo, el objetivo de este artículo es presentar las adaptaciones realizadas y analizar posibles soluciones a las dificultades encontradas en la práctica de la psicología clínica con pacientes con bajo nivel educativo y socioeconómico, a partir de un caso ilustrativo. Los resultados obtenidos, positivos, indican que las adaptaciones realizadas fueron fundamentales para el éxito de la terapia. Podemos concluir que el terapeuta debe estar atento a las demandas y particularidad del cliente a fin de que la terapia sea exitosa.

Resveratrol: A Potential Hippocampal Plasticity Enhancer.

The search for molecules capable of restoring altered hippocampal plasticity in psychiatric and neurological conditions is one of the most important tasks of modern neuroscience. It is well established that neural plasticity, such as the ability of the postnatal hippocampus to continuously generate newly functional neurons throughout life, a process called adult hippocampal neurogenesis (AHN), can be modulated not only by pharmacological agents, physical exercise, and environmental enrichment, but also by "nutraceutical" agents. In this review we focus on resveratrol, a phenol and phytoalexin found in the skin of grapes and red berries, as well as in nuts. Resveratrol has been reported to have antioxidant and antitumor properties, but its effects as a neural plasticity inducer are still debated. The current review examines recent evidence implicating resveratrol in regulating hippocampal neural plasticity and in mitigating the effects of various disorders and diseases on this important brain structure. Overall, findings show that resveratrol can improve cognition and mood and enhance hippocampal plasticity and AHN; however, some studies report opposite effects, with resveratrol inhibiting aspects of AHN. Therefore, further investigation is needed to resolve these controversies before resveratrol can be established as a safe coadjuvant in preventing and treating neuropsychiatric conditions.

Gender Differences in the Neurobiology of Anxiety: Focus on Adult Hippocampal Neurogenesis.

Although the literature reports a higher incidence of anxiety disorders in women, the majority of basic research has focused on male rodents, thus resulting in a lack of knowledge on the neurobiology of anxiety in females. Bridging this gap is crucial for the design of effective translational interventions in women. One of the key brain mechanisms likely to regulate anxious behavior is adult hippocampal neurogenesis (AHN). This review paper aims to discuss the evidence on the differences between male and female rodents with regard to anxiety-related behavior and physiology, with a special focus on AHN. The differences between male and female physiologies are greatly influenced by hormonal differences. Gonadal hormones and their fluctuations during the estrous cycle have often been identified as agents responsible for sexual dimorphism in behavior and AHN. During sexual maturity, hormone levels fluctuate cyclically in females more than in males, increasing the stress response and the susceptibility to anxiety. It is therefore of great importance that future research investigates anxiety and other neurophysiological aspects in the female model, so that results can be more accurately applicable to the female population.

Retinal development impairment and degenerative alterations in adult rats subjected to post-natal malnutrition.

BACKGROUND: The early stages of central nervous system (CNS) development are extremely important. Key events such as neurogenesis, gliogenesis, synaptogenesis, and ontogenesis occur. Malnutrition promotes alterations in CNS development, including the retinal development. During retinal development, malnutrition can induce a delay in some important events, such as neurotransmitter expression and neurogenesis. METHODOLOGY/PRINCIPAL FINDINGS: Postpartum Wistar rats were fed either a commercial diet or a multideficient diet. Pups were breastfed by these rats, and from PND21 were kept with the same diet until PND45. We investigated the effects of malnutrition on adult retinal tissue with regard to (1) endogenous gamma-amino butyric acid (GABA) release induced by excitatory amino acids (EAAs) and (2) the expression of cellular markers related to degenerative events, such as reactive gliosis, microglial activation, cell proliferation and cell death. Endogenous GABA release induced by EAAs was higher in the retina of malnourished rats. The Müller cell population was reduced and displayed alterations in their phenotype profile compatible with reactive gliosis. The expression of glutamine synthetase and markers of cellular proliferation were higher in the retina of malnourished rats. Additionally, retinal dysplasia-like structures were present, indicating disturbance in the cell cycle machinery. CONCLUSION/SIGNIFICANCE: The current study provides evidence that the adult retina shows degenerative processes induced by long-term malnutrition during the postnatal development. These findings have high clinical significance with regard to the identification of possible targets for interventions in malnourished patients.

Effects of diet on brain plasticity in animal and human studies: mind the gap.

Dietary interventions have emerged as effective environmental inducers of brain plasticity. Among these dietary interventions, we here highlight the impact of caloric restriction (CR: a consistent reduction of total daily food intake), intermittent fasting (IF, every-other-day feeding), and diet supplementation with polyphenols and polyunsaturated fatty acids (PUFAs) on markers of brain plasticity in animal studies. Moreover, we also discuss epidemiological and intervention studies reporting the effects of CR, IF and dietary polyphenols and PUFAs on learning, memory, and mood. In particular, we evaluate the gap in mechanistic understanding between recent findings from animal studies and those human studies reporting that these dietary factors can benefit cognition, mood, and anxiety, aging, and Alzheimer's disease-with focus on the enhancement of structural and functional plasticity markers in the hippocampus, such as increased expression of neurotrophic factors, synaptic function and adult neurogenesis. Lastly, we discuss some of the obstacles to harnessing the promising effects of diet on brain plasticity in animal studies into effective recommendations and interventions to promote healthy brain function in humans. Together, these data reinforce the important translational concept that diet, a modifiable lifestyle factor, holds the ability to modulate brain health and function.

Terapia cognitivo-comportamental e coaching cognitivo-comportamental: como as duas práticas se integram e se diferenciam / Cognitive-behavioural therapy and cognitive-behavioural coaching: differences and similarities between the two approaches

O coaching cognitivo-comportamental (CCC) é um processo estruturado de estabelecimento e alcance de metas que se fundamenta sobre o princípio cognitivo-comportamental, que pressupõe que não são os eventos em si que deflagram respostas emocionais e comportamentais, mas a interpretação que os indivíduos apresentam sobre eles. Nesse sentido, o CCC é um processo de identificação e desbloqueio de padrões cognitivos que dificultam a realização e o alcance de objetivos vinculado a planos de ação para a mudança comportamental, tendo sido descrito como método eficaz para o alcance de resultados na vida profissional e pessoal. No entanto, a interface dessa prática com a terapia cognitivo-comportamental (TCC) tem sido pouco investigada no Brasil. Assim, este artigo tem como objetivo discutir algumas das principais semelhanças e diferenças entre essas duas práticas. Pretende-se, com essa discussão, contribuir para o fortalecimento da prática profissional fundamentada sobre a abordagem cognitivo-comportamental para além do contexto clínico no nosso país, tendo em vista que o CCC visa atuar com clientes que não preencham critérios diagnósticos para transtornos mentais ou que simplesmente almejam alcançar uma experiência de viver mais plena e dotada de significado(AU)

Cognitive-behavioral coaching (CBC) is a structured process of goal establishment and attainment that is grounded on the cognitive-behavioral principle that emotional and behavioral responses are not triggered by events per se but by the individual's interpretation of them. In this respect, the CBC is a process of identifying and unblocking cognitive patterns that difficult goal achievement, tagged to action plans targeting behavioral change. CBC has been described as an effective method for achieving results in both professional and personal dimensions of life. However, the interface of this practice with CBT has been little investigated in Brazil. Thus, the present article aims at attempting to bridge this gap by presenting and discussing some of the main similarities and differences between these two practices. It is intended that this discussion will contribute towards the strengthening of cognitive-behavioral-grounded practices beyond the clinical context in our country, with patients who do not fulfill diagnostic criteria for mental disorders or with those who simply aim at developing a more purposeful experience of living(AU)

Hippocampal biomarkers of fear memory in an animal model of generalized anxiety disorder.

Generalized anxiety disorder (GAD) is highly prevalent and incapacitating. Here we used the Carioca High-Conditioned Freezing (CHF) rats, a previously validated animal model for GAD, to identify biomarkers and structural changes in the hippocampus that could be part of the underlying mechanisms of their high-anxiety profile. Spatial and fear memory was assessed in the Morris water maze and passive avoidance test. Serum corticosterone levels, immunofluorescence for glucocorticoid receptors (GR) in the dentate gyrus (DG), and western blotting for hippocampal brain derived neurotrophic factor (BDNF) were performed. Immunohistochemistry for markers of cell proliferation (bromodeoxiuridine/Ki-67), neuroblasts (doublecortin), and cell survival were undertaken in the DG, along with spine staining (Golgi) and dendritic arborization tracing. Hippocampal GABA release was assessed by neurochemical assay. Fear memory was higher among CHF rats whilst spatial learning was preserved. Serum corticosterone levels were increased, with decreased GR expression. No differences were observed in hippocampal cell proliferation/survival, but the number of newborn neurons was decreased, along with their number and length of tertiary dendrites. Increased expression of proBDNF and dendritic spines was observed; lower ratio of GABA release in the hippocampus was also verified. These findings suggest that generalized anxiety/fear could be associated with different hippocampal biomarkers, such as increased spine density, possibly as a compensatory mechanism for the decreased hippocampal number of neuroblasts and dendritic arborization triggered by high corticosterone. Disruption of GABAergic signaling and BDNF impairment are also proposed as part of the hippocampal mechanisms possibly underlying the anxious phenotype of this model.

The role of dietary polyphenols on adult hippocampal neurogenesis: molecular mechanisms and behavioural effects on depression and anxiety.

Although it has been long believed that new neurons were only generated during development, there is now growing evidence indicating that at least two regions in the brain are capable of continuously generating functional neurons: the subventricular zone and the dentate gyrus of the hippocampus. Adult hippocampal neurogenesis (AHN) is a widely observed phenomenon verified in different adult mammalian species including humans. Factors such as environmental enrichment, voluntary exercise, and diet have been linked to increased levels of AHN. Conversely, aging, stress, anxiety and depression have been suggested to hinder it. However, the mechanisms underlying these effects are still unclear and yet to be determined. In this paper, we discuss some recent findings addressing the effects of different dietary polyphenols on hippocampal cell proliferation and differentiation, models of anxiety, and depression as well as some proposed molecular mechanisms underlying those effects with particular focus on those related to AHN. As a whole, dietary polyphenols seem to exert positive effects on anxiety and depression, possibly in part via regulation of AHN. Studies on the effects of dietary polyphenols on behaviour and AHN may play an important role in the approach to use diet as part of the therapeutic interventions for mental-health-related conditions.

Current methodological designs of fMRI studies of panic disorder: can data be compared?

Panic disorder (PD) is a pluridimensional condition that leads to psychological suffering. Due to advances in neuroimaging techniques, important contributions have been made in the understanding of the neurobiological basis of PD. However, because of diverging research designs and protocols, more conclusive data concerning the neurocircuitry of PD remain difficult to achieve. To address this issue, a bibliographical search was performed using the Institute for Scientific Information Web of Science and Medline/PubMed databases. Fifteen articles were found, and their research methodology including sample, comorbidity, gender, and pharmacological criteria were explored. Although current functional magnetic resonance imaging studies of PD constitute fundamental tools for health sciences, more uniform research protocols must be implemented to provide more consistent and conclusive data concerning the neural substrates of PD.(AU)

Current methodological designs of fMRI studies of panic disorder: can data be compared?

Panic disorder (PD) is a pluridimensional condition that leads to psychological suffering. Due to advances in neuroimaging techniques, important contributions have been made in the understanding of the neurobiological basis of PD. However, because of diverging research designs and protocols, more conclusive data concerning the neurocircuitry of PD remain difficult to achieve. To address this issue, a bibliographical search was performed using the Institute for Scientific Information Web of Science and Medline/PubMed databases. Fifteen articles were found, and their research methodology including sample, comorbidity, gender, and pharmacological criteria were explored. Although current functional magnetic resonance imaging studies of PD constitute fundamental tools for health sciences, more uniform research protocols must be implemented to provide more consistent and conclusive data concerning the neural substrates of PD.

Current concept of anxiety: implications from Darwin to the DSM-V for the diagnosis of generalized anxiety disorder.

This article proposes a revision of the historical evolution of the concepts of generalized anxiety disorder (GAD). Currently, Darwin's evolutionary theory is the hegemonic paradigm for modern science and influences research on mental disorders. Throughout the 20th Century, the editions of the Diagnostic and Statistical Manual of Mental Disorders (DSM; American Psychiatric Association) have changed the diagnostic criteria for GAD, reflecting the prevailing psychiatric understanding of this disorder. The prevalence and symptoms of major depression and GAD show the fragility of the categorical conception of these conditions. Differences in cultural views towards anxiety disorders also suggest that anxiety cannot have a uniform definition. This article provides contributions for reflecting future guidelines concerning the diagnostic criteria for GAD in DSM-V.

Current findings of fMRI in panic disorder: contributions for the fear neurocircuitry and CBT effects.

Thanks to brain imaging great advances have been made concerning the comprehension of neural substrates related to panic disorder (PD). This article aims to: review the recent functional MRI (fMRI) studies concerning PD; correlate the PD fMRI neurobiological findings with the fear neurocircuitry hypothesis; discuss the fear neurocircuitry hypothesis and link it to cognitive-behavior therapy findings; and comment on fMRI study limitations and suggest methodological changes for future research. As a whole, there is increasing evidence that brain structures such as the prefrontal cortex, the anterior cingulate cortex and limbic areas (hippocampus and amygdala) might play a major role in the panic response.

Behavioral profile and dorsal hippocampal cells in carioca high-conditioned freezing rats.

Selection for contextual fear conditioning is an important behavioral paradigm for studying the role of genetic variables and their interaction with the surrounding environment in the etiology and development of anxiety disorders. Recently, a new line of animals selectively bred for high levels of freezing in response to contextual cues previously associated with footshock was developed from a Wistar population. The purpose of the present study was to evaluate the emotional and cognitive aspects of this new line of animals, which has been named Carioca High-Freezing (CHF). For the characterization of anxious behavior, CHF and control animals were tested in the elevated plus-maze (EPM) and the social interaction test. CHF animals were significantly more anxious than control rats in terms of both the number of entries into EPM open arms and the percentage of time spent in these arms. The time spent in social interaction behavior was also significantly decreased. No statistical differences were found in locomotor activity, as measured by both the number of entries into the closed arms of the EPM and the number of crossings into the social interaction test arena. No differences between CHF and control groups were found in the depression forced swimming test, suggesting that the anxiety trait selected in the CHF line did not interact with affective disorders traits such as those for depression. Cognitive aspects of the CHF rats were evaluated in the object recognition task. Results from this test indicated no difference between the two groups. The present study also encompassed histological analysis of the dorsal hippocampus from CHF and control animals. Results revealed an absence of qualitative and quantitative differences between these two groups of animals in cells located in the dentate gyrus, CA1, and CA3 areas. Therefore, future studies are required to further investigate the possible neural mechanisms involved in the origin and development of the anxious phenotype observed in this model.