RESUMO
Episodic memory depends on the recollection of spatial and temporal aspects of past experiences in which the hippocampus plays a critical role. Studies on hippocampal lesions in rodents have shown that dentate gyrus (DG) and CA3 are necessary to detect object displacement in memory tasks. However, the understanding of real-time oscillatory activity underlying memory discrimination of subtle and pronounced displacements remains elusive. Here, we chronically implanted microelectrode arrays in adult male Wistar rats to record network oscillations from DG, CA3, and CA1 of the dorsal hippocampus while animals executed an object recognition task of high and low spatial displacement tests (HD: 108 cm, and LD: 54 cm, respectively). Behavioral analysis showed that the animals discriminate between stationary and displaced objects in the HD but not LD conditions. To investigate the hypothesis that theta and gamma oscillations in different areas of the hippocampus support discrimination processes in a recognition memory task, we compared epochs of object exploration between HD and LD conditions as well as displaced and stationary objects. We observed that object exploration epochs were accompanied by strong rhythmic activity in the theta frequency (6-12 Hz) band in the three hippocampal areas. Comparison between test conditions revealed higher theta band power and higher theta-gamma phase-amplitude coupling in the DG during HD than LD conditions. Similarly, direct comparison between displaced and stationary objects within the HD test showed higher theta band power in CA3 during exploration of displaced objects. Moreover, the discrimination index between displaced and stationary objects directly correlated with CA1 gamma band power in epochs of object exploration. We thus conclude that theta and gamma oscillations in the dorsal hippocampus support the successful discrimination of object displacement in a recognition memory task.
RESUMO
BACKGROUND: Episodic-like memory tasks based on the spontaneous exploration of objects are commonly applied in one-trial protocols. However, multiple-trial designs are known to reduce animal numbers and data variance, providing faster accumulation of data. NEW METHOD: In this study, we devised a new object recognition memory task for rats that carry out multiple trials per session. We developed three types of continual trial tasks: a longer protocol, a shorter protocol, and a protocol in which the experimental session was divided into two days. RESULTS: In our design, rats expressed temporal and spatial memory, but not what-where-when content integration. We found that shorter protocols were more efficient to evaluate memory capabilities. COMPARISON WITH EXISTING METHODS: To the best of our knowledge, it is the first object recognition task with multiple trials that simultaneously assess the temporal and spatial aspects of episodic-like memory. CONCLUSIONS: We suggest that our task is suitable for the simultaneous measurements of brain functions related to spatial and temporal attributes in rats.
Assuntos
Comportamento Exploratório , Reconhecimento Psicológico , Animais , Ratos , Memória Espacial , Percepção VisualRESUMO
The aim of the present study was to evaluate the construct validity, internal consistency and psychometric indicators of the reduced version of the Cognitive Emotion Regulation Questionnaire (CERQ-short). The CERQ-short was adapted and translated to Portuguese prior to its administration to 254 adults, mainly from the state of Paraíba, Brazil. The Difficulties in Emotion Regulation Scale (DERS), the Compulsive Buying Scale (CBS) and a sociodemographic questionnaire were also applied. The original CERQ-short nine-factor structure was preserved. The convergent and discriminant validity, the reliability and the psychometric adequacy concerning item difficulty and item discrimination were also confirmed. The results support the use of this scale for rapid screening and research. (AU)
O presente estudo teve como objetivo buscar evidências de validade de construto, de consistência interna e indicadores psicométricos dos itens da versão adaptada para o português do Questionário Cognitivo de Regulação Emocional versão reduzida (CERQ-short). Após tradução e adaptação, foi aplicado o CERQ-Short, as escalas de dificuldade em regulação emocional (DERS) e de Compras Compulsivas (CBS), além de um questionário demográfico em uma amostra de 254 adultos, maioria de paraibanos. Verificou-se que a estrutura original de nove fatores do CERQ-Short foi mantida, também foram confirmadas as validades convergente e discriminante, a fidedignidade e a adequação psicométrica dos itens no que se refere à dificuldade e à discriminação dos itens. A escala apresentou evidência para a utilização em rastreio rápido e pesquisas. (AU)
El presente artículo tuvo como objetivo la búsqueda de evidencias de la validez del construto e indicadores psicométricos de los ítems, de una versión adaptada para el portugués, del Cuestionario Cognitivo de Regulación Emocional, versión reducida (CERQ-short). Inicialmente, fue realizada la traducción y adaptación semántica; posteriormente, fue aplicado el cuestionario CERQ-Short a las escalas de dificultad en regulación emocional (DERS) y de las Compras Compulsivas (CBS), además de un cuestionario demográfico en una muestra de 254 adultos, la mayoría de los paraibanos. Se verificó que la estructura original de nueve factores del CERQ-Short fue mantenida, así como las evidencias de validez del construto, fiabilidad y adecuación psicométrica de los ítems. La escala presentó evidencias para la utilización en rastreo rápido y pesquisas. (AU)
