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Social preference tests can be used to analyze variables that influence and modify social behaviors, and to investigate effects of substances such as medications, drugs, and hormones. They may become important tools for finding a valid model to study neuropsychiatric changes and to study human neurodevelopmental processes that have been impaired by social events. While a preference for conspecifics has been shown for different species, social novelty has been used as a model for anxiety-like behavior in rodents. The goal of this research was to understand the roles of stimulus salience (numerousness) and novelty in social investigation and social novelty tests in zebrafish (Danio rerio Hamilton 1822). We used a sequential design, in which animals are exposed first to a social investigation test (with dichotomous presentation of novel conspecifics vs. empty tank) and then to a social novelty test (with dichotomous presentation of the already known conspecific and a novel conspecific). In experiment 1, animals were presented to either 1 or 3 (vs. an empty tank) conspecifics as stimuli. In experiment 2, animals were presented to 1 vs. 3 conspecifics as stimuli. In experiment 3, animals were observed in the social investigation and social novelty tests for 3 consecutive days. The results showed equivalence between 1 or 3 conspecifics in the social investigation and social novelty tests, although animals were able to discriminate between different shoal sizes. These preferences do not change with repeated test exposure, suggesting novelty to be a minor contributor to social investigation and social novelty in zebrafish.

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Serotonin (5-HT) receptors have been implicated in social behavior in vertebrates. Zebrafish (Danio rerio) have been increasingly being used behavioral neuroscience to study the neurobiological correlates of behavior, including sociality. Nonetheless, the role of 5-HT2C receptors in different social functions were not yet studied in this species. Zebrafish were treated with the agonist MK-212 (2 mg/kg) or the antagonist RS-102221 (2 mg/kg) and tested in the social interaction and social novelty tests, conditional approach test, or mirror-induced aggressive displays. MK-212 increased preference for an unknown conspecific in the social investigation test, but also increased preference for the known conspecific in the social novelty test; RS-102221, on the other hand, decreased preference in the social investigation test but increased preference for the novel conspecific in the social novelty test. MK-212 also decreased predator inspection in the conditional approach test. While RS-102221 decreased time in the display zone in the mirror-induced aggressive display test, it increased display duration. Overall, these results demonstrate the complex role of 5-HT2C receptors in different social contexts in zebrafish, revealing a participation in social plasticity in vertebrates.

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Resumen El artículo analiza la emergencia de los Estudios Locos como tradición investigativa que propone teorías críticas y metodologías alternativas en la producción de saberes desde las personas que han sido etiquetadas con diagnósticos psiquiátricos. Para los Estudios Locos, los significados en torno a la locura expresan la relación de fuerzas y las formas de opresión que constituyen el campo de la salud mental, por lo tanto, enfatizan el carácter político de las investigaciones que se desarrollan en este ámbito y sostienen un cuestionamiento a la pretensión de objetividad y neutralidad del modelo biomédico. En este marco, mediante una revisión de la literatura académica y la netnografía como método de investigación, se describe el creciente protagonismo de las comunidades que han recibido atención de salud mental en América Latina para expresar sus narrativas en la esfera pública, situándose como agentes de conocimientos y actores políticos. En torno a estas nuevas gramáticas, los Estudios Locos Latinoamericanos se constituyen como una perspectiva de investigación hacia la configuración de otros modos de habitar la locura y articular sus luchas de emancipación social en el escenario regional contemporáneo.

Resumo Este artigo analisa a emergência dos Estudos loucos como uma tradição investigativa que propõe teorias críticas e metodologias alternativas para a produção do conhecimento de pessoas que foram rotuladas com diagnósticos psiquiátricos. Para Estudos loucos, os significados em torno da loucura expressam a relação de forças e as formas de opressão que constituem o campo da saúde mental, portanto, enfatizam o caráter político das pesquisas que se desenvolvem neste campo e sustentam um questionamento da reivindicação de objetividade e neutralidade do modelo biomédico. Nesse quadro, por meio de uma revisão da literatura acadêmica e da netnografia como método de pesquisa, descreve-se o crescente papel das comunidades que receberam atenção em saúde mental na América Latina para elaborar suas experiências no campo acadêmico e expressar suas narrativas em público. esfera, posicionando-se como agentes do conhecimento e atores políticos. Em torno dessas novas gramáticas, propõe-se o surgimento dos Estudos loucos da América Latina como disciplina emergente na configuração de outras formas de habitar a loucura e articular suas lutas pela emancipação social no cenário regional contemporâneo.

Abstract This article analyzes the emergence of Mad Studies as an investigative tradition that proposes critical theories and alternative methodologies in the production of knowledge from people who have been labeled with psychiatric diagnoses. For Mad Studies, the meanings around Madness express the relationship of forces and the forms of oppression that constitute the field of mental health, therefore, they emphasize the political nature of the research that is developed in this field and sustain a questioning of the claim of objectivity and neutrality of the biomedical model. In this framework, through a review of the academic literature and netnography as a research method, the growing role of the communities that have received mental health care in Latin America to express their narratives in the public sphere is described, positioning themselves as agents of knowledge and political actors. Around these new grammars, Latin American Mad Studies are constituted as a research perspective towards the configuration of other ways of inhabiting madness and articulating their struggles for social emancipation in the contemporary regional scenario.

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This study employed the intruder-resident paradigm to evaluate the effects of continuous social defeat on depressive- and anxiety-like behaviors and the reinforcing and motivational actions of ethanol in male Swiss mice. Male Swiss mice were exposed to a 10-day social defeat protocol, while control mice cohabitated with a non-aggressive animal. Continuous defeat stress consisted of episodes of defeat, followed by 24h or 48h cohabitation with the aggressor until the following defeat. Mice were assessed for sucrose drinking (anhedonia), social investigation test, elevated plus-maze, conditioned place preference to ethanol, and locomotor response to ethanol. Plasma corticosterone was measured prior to, after the first and the final defeat, and 10days after the end of defeat. Defeated mice exhibited a depressive-like phenotype as indicated by social inhibition and reduced sucrose preference, relative to non-defeated controls. Defeated mice also displayed anxiety-like behavior when tested in the elevated plus-maze. Stressed animals failed to present ethanol-induced locomotor stimulation, but showed increased sensitivity for ethanol-induced conditioned place preference. Corticosterone response to defeat was the highest after the first defeat, but was still elevated after the last defeat (day 10) when compared to non-stressed controls. Baseline corticosterone levels were unchanged 10days after the final defeat. These data suggest that social defeat stress increased depressive- and anxiety-like behavior as well increased vulnerability to ethanol reward in mice.

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In rodents, chronic social defeat stress promotes deficits in social interest and social interaction. We further explored these antisocial effects by comparing the consequences of two different defeat stress protocols (episodic vs. continuous stress) in a social investigation test. We expected that continuous, but not episodic, stress would induce social deficits in this model. Furthermore, we tested whether a potentially anxiolytic dose of ethanol reverses social deficits induced by defeat stress. Male Swiss mice were exposed to a 10-day social defeat protocol, using daily confrontations with an aggressive resident mouse. Episodic stress consisted of brief defeat episodes, after which the defeated mouse was returned to its home cage, until the next defeat 24 h later (n = 7-11/group). For continuous stress, similar defeat episodes were followed by cohabitation with the aggressive resident for 24 h, separated by a perforated divider, until the following defeat (n = 8-14/group). Eight days after stress termination, defeated and control mice were assessed in a social investigation test, after treatment with ethanol (1.0 g/kg, i.p.) or 0.9% saline. Considering the time spent investigating a social target, mice exposed to episodic or continuous social stress showed less social investigation than controls (p < .05). Deficits in social interest were not reversed by acute ethanol treatment. However, ethanol reduced time spent in social interaction in one control group (p < .05). Locomotor activity was not affected by social stress or ethanol. Thus, a history of social defeat stress, whether episodic or continuous, promotes deficits in social investigation that were not reversed by acute treatment with ethanol.

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A modified version of the intruder-resident paradigm was used to investigate if social recognition memory lasts at least 24 h. One hundred and forty-six adult male Wistar rats were used. Independent groups of rats were exposed to an intruder for 0.083, 0.5, 2, 24, or 168 h and tested 24 h after the first encounter with the familiar or a different conspecific. Factor analysis was employed to identify associations between behaviors and treatments. Resident rats exhibited a 24-h social recognition memory, as indicated by a 3- to 5-fold decrease in social behaviors in the second encounter with the same conspecific compared to those observed for a different conspecific, when the duration of the first encounter was 2 h or longer. It was possible to distinguish between two different categories of social behaviors and their expression depended on the duration of the first encounter. Sniffing the anogenital area (49.9 percent of the social behaviors), sniffing the body (17.9 percent), sniffing the head (3 percent), and following the conspecific (3.1 percent), exhibited mostly by resident rats, characterized social investigation and revealed long-term social recognition memory. However, dominance (23.8 percent) and mild aggression (2.3 percent), exhibited by both resident and intruders, characterized social agonistic behaviors and were not affected by memory. Differently, sniffing the environment (76.8 percent of the non-social behaviors) and rearing (14.3 percent), both exhibited mostly by adult intruder rats, characterized non-social behaviors. Together, these results show that social recognition memory in rats may last at least 24 h after a 2-h or longer exposure to the conspecific.

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