The contextual fear conditioning consolidation depends on the functional interaction of the dorsal subiculum and basolateral amygdala in rats.

Fear conditioning tasks enable us to explore the neural basis of adaptative and maladaptive behaviors related to aversive memories. Recently, we provided the first evidence of the dorsal subiculum (DSub) involvement in contextual fear conditioning (CFC) consolidation by showing that the post-training bilateral NMDA (N-methyl-D-aspartate) receptor blockade in DSub impaired the performance of animals in the test session. As the memory consolidation process depends on the coordinated engagement of different brain regions, and the DSub share reciprocal projections with the basolateral amygdala (BLA), which is also involved in CFC, it is possible that the functional interaction between these sites can be relevant for the consolidation of this task. In this sense, the present study aimed to explore the effects of the functional disconnection of the DSub and BLA in the CFC consolidation after NMDA post-training blockade. In addition, to verify if the observed effects were due to spatial representation processes mediated by the DSub, we employed a hippocampal-independent procedure: tone fear conditioning (TFC). Results showed that the functional disconnection of these regions by post-training NMDA blockade impaired CFC consolidation, whereas there was no impairment in TFC. Altogether, the present data suggest that the DSub and BLA would functionally interact through NMDA-related synaptic plasticity to support CFC consolidation probably due to DSub-related spatial processing showing that the TFC consolidation was not disrupted. This work contributes to filling a gap of studies exploring the DSub involvement in fear conditioning by providing a broad framework of the subicular-amygdaloid connection functionality.

Agressividade e psicopatia: um estudo comparativo entre detentos e adolescentes / Aggression and psychopathy: a comparative study between prisoners and adolescents / Agresividad y psicopatía: un estudio comparativo entre prisionesros y adolescentes

A agressividade e a psicopatia estão relacionadas com o funcionamento do córtex pré-frontal (CPF), cuja maturação leva aproximadamente 21 anos. Assim, objetivou-se identificar a existência de diferenças entre um grupo de adolescentes, com no máximo 20 anos de idade, e um grupo de detentos no tocante ao nível de agressividade e psicopatia. Para tanto, contou-se com a participação de 48 detentos do sexo masculino, com idade média de 34,6 (DP = 8,68) e 48 adolescentes do sexo masculino, com idade média de 17,75 (DP = 1,15). Os participantes responderam ao Questionário de Agressão de Buss-Perry, a Levenson Self-Report Psychopathy scale (LSRS) e a um questionário sociodemográfico. Os resultados dos testes Mann-Whitney e teste t de student indicaram a existência de diferenças significativas apenas para a psicopatia secundária, sendo mais característica em detentos. Os achados foram discutidos considerando a relação do desenvolvimento do CPF com fatores ambientais

Aggression and psychopathy are prefrontal cortex (PFC) activity-related and the maturation of this region takes approximately 21 years. Our aim was to assess differences in aggression and psychopathy levels between an adolescent group (máx age 20) and a prisoner group. It counted with a sample of 48 male prisoners mean aged 34,6 (SD = 3.66) and 48 male adolescents mean aged 17,75 (SD = 1.5). The participants answered the Buss-Perry Aggression Questionnaire; the Levenson Levenson Self-Report Psychopathy Scale (LSRS) and a demographic questionnaire. The Mann-Whitney test and the Student's t-test results shown significant differences only for secondary psychopathy, which was higher in the prisoner group. Our findings were discussed considering the relationship between the PFC development and external factors

La agresividad y la psicopatía están relacionadas con el funcionamiento de la corteza prefrontal (CPF), cuya maduración tarda aproximadamente 21 años. Por lo tanto, el objetivo era identificar la existencia de diferencias entre un grupo de adolescentes, con un máximo de 20 años de edad, y un grupo de prisioneros, con respecto al nivel de agresión y psicopatía. Para ello, participaron del estudio 48 prisioneros de sexo masculino, con una edad promedio de 34,6 (DE = 8,68) y 48 adolescentes de sexo masculino, con una edad promedio de 17,75 (DE = 1,15). Los participantes respondieron al Cuestionario de Agresión de Buss-Perry, al Levenson Self-Report Psychopathy scale ­ LSRS y a un cuetionario sociodemográfico. Los resultados de los testes de Mann-Whitney y de t de Student indicaron diferencias significativas solo para la psicopatía secundaria, siendo más característicos en los prisioneros. Los hallazgos se discutieron como base en la relación del desarrollo de la CPF con factores ambientales

The dorsal subiculum is not necessary for step-through inhibitory avoidance acquisition and consolidation in rats.

The dorsal subiculum (DSub) has reciprocal connections with the dorsal hippocampus, and these regions play a role in spatial representation in contextual fear conditioning (CFC). Recently, we used AP5 and muscimol infusions to show that the DSub is required for CFC consolidation. The CFC component can be present in other learning tasks, such as step-through inhibitory avoidance (ST IA), which requires the dorsal hippocampus for acquisition and consolidation. This suggests that the DSub may be also involved in ST IA if the CFC component of the protocol is strong enough. Therefore, this study tested whether the DSub participates in ST IA acquisition and consolidation in male Wistar rats. Our data showed that pre-or posttraining infusions of AP5 or muscimol into the DSub did not affect ST IA acquisition and consolidation. We discuss the present results in relation to our previous findings, which showed the involvement of the DSub in CFC consolidation, and highlight some reasons that may explain the divergent results between the tasks. First, we note the possibility to escape from the unconditioned stimulus that occurs in ST IA, but not in CFC. We also suggest that the instrumental component of ST IA seems to be more prominent than the CFC one. Finally, we consider the possible influence of aspects of anxiety present in the ST IA, but not in CFC. These possible interpretations provide a broad framework in respect of the present results and raise new questions that demand further studies exploring the DSub function in inhibitory avoidance. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

The dorsal subiculum is required for contextual fear conditioning consolidation in rats.

The hippocampal formation has a well-known role in contextual fear conditioning. The dorsal subiculum connects the hippocampus to the entorhinal cortex through pathways that seemingly rely on NMDA-dependent synaptic plasticity. The role of the dorsal subiculum in contextual fear conditioning retrieval, but not acquisition, has been previously reported. However, most of the critical biological phenomena involved in memory formation occur in the consolidation phase. The present study aimed to assess the effects of intra-dorsal subiculum muscimol or AP5 infusion on contextual fear conditioning consolidation. Our data show that dorsal subiculum integrity, as well as NMDA transmission in this region, seem to be necessary for contextual fear conditioning consolidation.