Topic: contextual memory

The neural basis underlying the relationship between a contextual memory and its constituent features is not well understood; in particular, where features are represented in the brain and how they drive memory recall. To gain insight into this question, we developed a behavioral task where mice use features to recall an associated contextual memory. We performed longitudinal imaging in hippocampus as mice performed this task and identified robust representations of global context. To identify putative brain regions that provide feature inputs to the hippocampus, we inhibited cortical afferent

The ability to form associations is one of the fundamental features of the brain. Pavlov's original work on classical conditioning employed CS that immediately preceded reinforcement. Here, using the model of context preexposure (Rudy, O'Reilly, 2001; Vorobieva et al., 2017), we studied how an engram of a distant past context can become a CS. Mice explored a new context, and then with different delays (from 30 minutes up to 30 days) received an immediate shock in the same environment. We showed that contextual memory engram can be conditioned at all tested intervals. We then used c-Fos express

Sex and age play significant roles in spatial and contextual memory formation; however, these factors are understudied especially considering the ongoing maturation of prefrontal cortex and hippocampus through juvenility until adulthood. The receptor of Oxytocin (OXTR) has sex-dimorphic characteristics and is expressed in these regions. We previously demonstrated that blockade of prefrontal OXTR impaired extinction of contextual fear memory in juvenile females but not males (Maroun 2020). The hippocampus is central to spatial memory formation and performance in spatial memory tasks is age and

In this study, we investigate how contextual memory is shaped by observational fear learning during encoding and recall. We are imaging neurons in layer 2/3 of the retrosplenial cortex in GCaMP6s mice with two-photon Ca2+ imaging using a head-fixed observational fear learning paradigm in virtual reality. The animals are surrounded by three screens and run on a running wheel as they travel through 3 different VR environments. In two of the environments, we play recordings of mouse vocalisations emitted while they were receiving foot shocks, and a neutral sound in the third environment. A single

The ventral midline thalamic reuniens/rhomboid (ReRh) nuclei, have been implicated in contextual and spatial memory persistence. Based on its bidirectional connections with the medial prefrontal cortex (mPFC) and hippocampus, the ReRh serves as a critical relay in the transfer of information between both structures, holding a key position to regulate cortico-hippocampal interactions. This interplay is not only essential for systemic consolidation of spatial and contextual memories but might also be required in spatial working memory. Based on the idea that interactions crucial for subsequent s

Alzheimer's disease (AD) is characterized by a dramatic loss of old consolidated memory. Our study proposes a new hypothesis that neurodegeneration affects mechanisms of memory reconsolidation, leading to the weakening of old memories when they are retrieved in the diseased brain, resulting in gradual self-degradation of the consolidated memory. Testing this hypothesis in transgenic 5xFAD mice we found that their contextual memory was impaired following retrieval compared to control animals. To protect memory during reconsolidation, we administered the NMDA receptor antagonist MK-801 which is