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

• Published in: Neurobiology of learning and memory Vol. 205; p. 107827
• Main Authors: Melo, Márcio Braga de, Favaro, Vanessa Manchim, Oliveira, Maria Gabriela Menezes
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-11-2023
• Subjects: Amygdala; AP5; Fear conditioning; Functional disconnection; Subiculum; CFC; Amygdala; AP5; GEE; Long-term potentiation; Functional disconnection; GLM; CONT; Fear conditioning; TFC; BLA; NMDA; Subiculum; DSub; IPSI
• ISSN: 1074-7427; 1095-9564
• DOI: 10.1016/j.nlm.2023.107827

•The DSub-BLA disconnection by using NMDA blockade impairs the CFC consolidation;•This same disconnection does not affect the TFC consolidation;•This suggests that the CFC effect is probably due to related spatial processing;•This study helps to filling a gap of works exploring the DSub in fear conditioning.
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.