Animal models of anxiety disorders and stress

Abstract

Anxiety and stress-related disorders are severe psychiatric conditions that affect performance in daily tasks and represent a high cost to public health. The initial observation of Charles Darwin that animals and human beings share similar characteristics in the expression of emotion raise the possibility of studying the mechanisms of psychiatric disorders in other mammals (mainly rodents). The development of animal models of anxiety and stress has helped to identify the pharmacological mechanisms and potential clinical effects of several drugs. Animal models of anxiety are based on conflict situations that can generate opposite motivational states induced by approach-avoidance situations. The present review revisited the main rodent models of anxiety and stress responses used worldwide. Here we defined as ''ethological'' the tests that assess unlearned/unpunished responses (such as the elevated plus maze, light-dark box, and open field), whereas models that involve learned/ punished responses are referred to as ''conditioned operant conflict tests'' (such as the Vogel conflict test). We also discussed models that involve mainly classical conditioning tests (fear conditioning). Finally, we addressed the main protocols used to induce stress responses in rodents, including psychosocial (social defeat and neonatal isolation stress), physical (restraint stress), and chronic unpredictable stress.

Central relaxin-3 receptor (RXFP3) activation reduces elevated, but not basal, anxiety-like behaviour in C57BL/6J mice

“…Elevated levels of anxiety are often associated with heightened stress, linked to combined developmental and traumatic life-events and can be modelled experimentally in animals by subjecting them to acute or chronic stressors, such as predator exposure, neonatal isolation, social defeat, restraint, or chronic unpredictable stress [7]; or treatment with anxiogenic drugs, such as yohimbine or FG-7142 [8][9][10]. Using these animal models, it is possible to investigate the effectiveness of putative novel treatments and identify new molecular targets or signalling systems for improving existing therapeutics [11,12].…”

Animal Models for Psychiatry

“…To address the current understanding of this important area of basic science in psychiatry, this supplement of Revista Brasileira de Psiquiatria brings several reviews on animal models of anxiety/stress, 6 depression, 8,9 psychosis, 10 alcohol and drug dependence, 11 and neurodegenerative diseases.…”

Possível envolvimento do monóxido de carbono na modulação do comportamento emocional em ratos: o papel do locus coeruleus

“…Dentre as distintas emoções inatas, estudos pioneiros de Darwin (1965) descreveram o caráter evolutivo da expressão das emoções nos homens, sendo observado respostas semelhantes àquelas expressas por outros animais, em particular, do medo e da raiva. Tal semelhança levou ao estudo aprofundado das respostas comportamentais acionadas pelo medo em animais na busca pela compreensão dos estados emocionais aversivos em seres humanos, os quais podem ser relacionados não apenas com estados emocionais de medo e ansiedade do cotidiano, mas também com desordens psiquiátricas (Campos et al, 2013).…”

“…Em relação ao aspecto etológico do medo e da ansiedade, alguns autores sugerem que estas respostas estejam relacionadas à proximidade de um estímulo ameaçador, podendo ser proximal (pânico), distal/conhecido (medo) ou potencial/desconhecido (ansiedade) (Campos et al, 2013;Graeff e Guimarães, 2012). Assim, a proximidade com um predador (medo) ou um ambiente desconhecido (ansiedade) podem provocar ativação de diferentes circuitos neurais (Moobs e Kim, 2015).…”

“…Diversos modelos animais para o estudo da ansiedade têm sido propostos ao longo dos anos (Campos et al, 2013). Dentre eles, os mais utilizados são o labirinto em cruz elevado (Pellow et al, 1985;Cruz et al, 1994;Rodgers e Dalvi, 1997;Wall e Messier, 2001;Albrechet-Souza et al, 2008;Saito e Brandão, 2014) e o teste de claro-escuro (Hascoet et al, 2001;Bourin e Hascoet, 2003).…”