Retrosplenial cortex

…and decisions, endogenous opioids, retrosplenial cortex, and activity-dependent plasticity in sensory pathways. Morning and evening symposia leave time for informal scientific discussion. Attendance is capped below 100. R

…behavior (the orbitofrontal cortex, OFC) and navigation (the retrosplenial cortex, RSC), orchestrates the transition between competing goals during navigation. To explore this, we designed a virtual-reality maze task for two Rhesus monkeys, wher

…The retrosplenial cortex (RSC) is one of the regions affected by amyloidosis in the early stages of AD and is well known for its role in egocentric spatial representation. Specifically, it cont

Navigating towards goals in crowded spaces is a complex behavior that requires keeping track of relative positions of goals and obstacles. Animals can solve this by breaking down routes into subgoals - intermediate waypoints. It is not known how the brain represents subgoals, or how their representation differs from static spatial features of the environment. Building on work showing that mice use a subgoal strategy to escape to shelter, we placed mice in an arena divided in half by a barrier, with a shelter in the bottom half. The barrier leaves a gap on one side which mice learn to use as a

Working memory, the process through which information is transiently maintained and manipulated over a brief period, is essential for most cognitive functions. However, the mechanisms underlying the generation and evolution of working- memory neuronal representations at the population level over long timescales remain unclear. Here, to identify these mechanisms, we trained head-fixed mice to perform an olfactory delayed-association task in which the mice made decisions depending on the sequential identity of two odours separated by a 5 s delay. Optogenetic inhibition of secondary motor neurons

…such as hippocampus and the prefrontal cortex. Here, we are currently investigating how wider cortical networks support memory reprocessing. We are doing so by combining optical (wide-field) voltage imaging with laminarly-resolved hippocampal electrophysiology in mice, to get a large-scale view of the brain activity. Animals perform two virtual reality memory tas

Episodic memories are crucial elements that determine our sense of identity. Episodic memory formation is mostly dependent on the proper function of the hippocampus. However, mechanisms of episodic memory formation, maintenance and retrieval are only beginning to be elucidated. One of the leading scientific theories about the hippocampal role in memory is indexing theory. This concept builds on the premise that hippocampal neurons are multi-synaptically bi-directionally linked with sensory and associative cortical regions. Nevertheless, it is not clear if cortical reinstating occurs on a neuro

…between the hippocampus and neocortex. It is therefore important to assess the developmental timeline of

The retrosplenial cortex (RSC) is known for its pivotal role in contextual fear conditioning, receiving inputs from both corticocortical and subcortical pathways, including the nucleus incertus in the pontine tegmentum. This region contains a GABAergic projection rich in relaxin-3 (RLN3), which acts via its Gi/o-protein-coupled receptor, RXFP3. To investigate the involvement of this peptidergic system in contextual fear conditioning, we bilaterally injected adult rat RSC with an adeno-associated virus (AAV) expressing the chimeric RXFP3 agonist R3/I5 or a control AAV and subjected them to cont

High-throughput electrophysiological recordings, using multichannel silicon probes, allow simultaneous registration of neural activity from multiple brain regions. However, the difficulty of determining the precise localisation of recording sites within neural subcompartments creates challenges for data analysis and the interpretation of experimental results. While electrode localisation can be achieved to some extent by post-mortem histological reconstruction of the probes, it can be improved by real-time discrimination of the electrophysiological features of the signal: evoked potentials tri

…ensemble reactivation in the neocortex. This orchestrated mechanism is essential for transferring memory traces from the hippocampus to long-term storage in the neocortex. Following memory consolidation in the neocortex, it is hypothesized that downstream neuronal ensembles are stabilized in diverse cortical regions. The stability of neuronal ensembles across several months has not been

…between the hippocampus and neocortex. The hippocampus encodes novel episodes using sparse and orthogonal neural representations, which form and stabilize within ~10 minutes in a novel environment. Recent studies have shown that several neocortical areas, including the retrosplenial cortex (RSC), primary somatosensory cortex (S1), and primary visual cortex (V1) contain sparse neural coding correlated to spatial location in one-dimensional environments. This spatial coding depends on an intact hipp

…of chondroitinase ABC (ChABC) into the retrosplenial cortex of healthy adult mice. Using in vivo two-photon microscopy we found that ChABC treatment increased microglial branching and ECM phagocytic capacity and decreased spine elimination rate under basal conditions. Moreover, ECM attenuation largely prevented sy

Strategy updating is one of the recent roles assigned to the retrosplenial cortex (RSC). Studies have shown that lesions or inactivation of RSC cause impairment in exploring and learning new alternative options when previous ones were available but no longer appropriate, suggesting its importance for set-shifting behaviors1. Building on previous evidence of impaired reversal learning in 6-month-old 5xFAD mice2, this study focuses on uncovering the synaptic correlates of reversal learning in the RSC in the context of AD. Therefore, we use a set-shifting task that challenges the animals to devel

Silicon electrode arrays with thousands of channels enable read-out of the activity of large populations of neurons, but they induce chronic inflammation in the brain and a decline in signal quality. On the other hand, existing flexible electrode arrays have limitations on how reliably they can be inserted into any targeted depth in the brain while maintaining a high density of recording channels. To address these problems, we developed Ultra-Flexible Tentacle Electrodes (UFTE), where each recording channel is mechanically independent to provide maximal compliance with brain tissue—while also

Posttraumatic stress disorder (PTSD) manifests in some trauma-exposed individuals through excessive fear generalization to safe contexts and difficulties extinguishing fear. While previous studies have implicated functional changes in fear-regulatory nodes a comprehensive understanding of network-wide alterations remains elusive. We employed a rodent model of PTSD to investigate whole-brain activity patterns associated with fear generalization. Male rats underwent uncontrollable footshocks and 28 days later we measured their generalized fear response in an altered/safe context. Based on freezi

Over the past decade, considerable research has delved into the Retrosplenial Cortex's (RSC) critical function in spatial navigation, employing allocentric and egocentric frames of reference to interact with its surroundings. Andy Alexander's 2018 study on Egocentric Boundary Vector Cells (EBVCs) in the RSC in an open-field arena marked a significant advancement in our understanding. Building on this foundation, our study extends the investigation into EBVCs' roles in navigation within an open field context and in a dynamic egocentric task—specifically, a rat pursuing a bait within the same en

…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 retrosplenial cortex (RSC) and hippocampus support the encoding, storage, and retrieval of different aspects of associative experience. In the hippocampus, learning and updating information about the content details of space triggers long-term depression (LTD) (doi: 10.3389/fnbeh.2022.806356) . Here we used fluorescence in situ hybridization (FISH) explore to what extent this kind of spatial content learning triggers somatic immediate early gene (IEG i.e. Homer1a) expression in the cornus ammonis and RSC, as an indication of active storage of learned experience. Adult rats explored novel s

Fact knowledge – known as semantic memories – is proposed to be derived from individual memories of events during a memory consolidation period after learning. But so far, this has never been shown. Here, we tracked gene expression in a 2-week semantic-like memory paradigm in mice across the whole-brain spatial memory network. Absolute gene expression was driven by first experiences and later learning led to smaller changes, highlighting that multiple episodic memories are not encoded and then consolidated to create semantic-memories, instead already by the second experience semantic-memories

…the activity of neurons located in the retrosplenial cortex (RSC) is increased during R

The study of rodent navigation has for decades focused on the hippocampal and parahippocampal regions, although recently part of this focus has shifted towards whether positional information can be identified in lower association cortices or even primary sensory areas. Spatial representation in these regions is often investigated using one-dimensional paradigms in combination with virtual reality. In the present work, we seek to understand how position is encoded in a more naturalistic, two-dimensional environment. Starting at the sensory level and moving up to higher association areas we aim

…and it sends HD information to the retrosplenial cortex (RSC) and presubiculum (PrS). However, it has been unclear which thalamic neurons target RSC or PrS. Moreover, the input connectivity from the upstream lateral mammillary nucleus (LMN) is has not been clearl

In reversal learning tasks, large-scale circuits in multiple brain areas are involved in encoding multiple decision variables, such as trial outcomes, action values and action switching. It is unknown how spatiotemporal patterns of cortical encoding differentially encode these variables and whether the encoding depends on the level of engagement in the task. Here, we used a combination of large-scale imaging techniques and computational methods to investigate the representation of reward-related decision variables at the widefield and single-neuron levels. Widefield imaging and unsupervised an