Place cells

…Hippocampal place cells exhibit representational drift (Ziv et al., 2013), but this has only been characterized with somatic recordings. While dendritic activity is implicated in the formation of stable place fields and shaping hippocampal activity, in vivo studies of hippocampal dendritic activity have largely been confined to basal dendrites (Sheffield and Dombeck, 2015) or small cross-sections of apical den

…by mammalian hippocampal grid and place cells, forming low-dimensional neural manifolds that support flexible navigation. However, beyond simple line and ring attractors, how the brain represents and navigates more complex neural manifolds remains unclear. In this study, we propose a solution for representing arbitrary nonlinear neural manifolds by approximating them with piecewise linear spaces composed of simplexes, known as “simplicial compl

…While hippocampal place cells are traditionally linked to representing spatial location information, rodent studies have shown that they also exhibit predictive coding and reward-dependent place fields, suggesting their role extends beyond spatial representation. The Successor Representati

…related to immediate space, such as place cells. We aimed to test whether hippocampus, known for supporting spatial maps in physical environments, can localize the source of remote auditory signal and rewards associated with its spatial position. Given previous evidence for auditory sensitivity in the hippocampus [1-2], we recorded extracellular electrophysiological activity from auditory cortex and intermediate-ventral hippocampus simultaneously, us

…hippocampus is well-established and place cells, border cells and others have been identified, the precise representational strategies of valence information remain elusive. Here, we study how learning combines spatial and affective knowledge in the population activity of ventral-to-dorsal (valence-tuned) and dorsal-to-dorsal (space-tuned) pathways in the CA3 region. Do inc

…of CA1 spatial-tuning neurons, or 'place cells,' known as theta sequences. However, it remains unclear how theta supports memory during periods of immobility, when CA1 theta oscillations dissipate. To address this, we recorded laminar neural activity using

…the spatial preferences of hippocampal place cells in response to environmental changes. Disparate neural representations in different environments could reduce interference between competing memories, hence functionally supporting robust context-dependent spatial cognition. Experimental data on existing remapping studies exhibit a diverse range of physiological properties, sometimes with seemingly conflicting results. In particular, subtle changes in experimental conditions lead to qualitatively different results. De

…Additionally, place cells exhibit remapping across low/high-pitch states. In our study using a path-integration paradigm with rats, we found that parameters

…space, suggested by spatially tuned cells (place cells, grid cells, etc.) recorded in nonhuman animals. In an attempt to reconcile the two views, we use a memory-augmented neural network in a reinforcement learning setup to solve a navigation task in a simulated maze. The key feature of the model is that it learns autonomously what and when to store into, and retrieve from, an external memory buffer. Once the mode

…The activity of place cells and boundary cells were fed as inputs to action selection neurons, which

…of space using a prominent feature – place cells [1] (PCs). It is unclear how PCs’ neural codes are related to memory: turnover of neural representations could be involved in learning, while codes’ stability may support long-term storage and retrieval of memories [2]. In this work, we focus on the analysis of one-photon (1P) calcium imaging data recorded from mouse CA1 during free foraging in a two-dimensional arena with the help of a miniature

…Place cells, specialised neurons residing within the hippocampus, exhibit selective firing patterns corresponding to specific spatial locations, collectively contributing to the cognitive mapping of the environment. In healthy state, the place fields in the CA1 region exhibits continuous representational turnover [1]. Spatial navigation is disrupted in Alzheimer’s Disease (AD). AD, a neurodegenerative disorder characterised by progressive cognitive decline, is associated with deficits in learning a

…hippocampal area CA1 features spatial cells that adapt based on behavior and internal states. Computational models have usually obtained spatial tuning by training a deep recurrent network for solving path integration, over numerous epochs, using backpropagation [1, 2, 3]. However, such methods do not closely align with the real-time local learning used by animals. Additionally, the formed spatial maps are solely oriented towards solving a specific task, and fail to c

Experimental studies have demonstrated that spontaneous task-independent replay of sequences encoding a learned route during sharp-wave–ripple (SWR) events can be beneficial for consolidating path memory [1] and discovering new behavioral strategies, such as forming novel space-action representations, finding shortcuts, and integrating and associating different routes[2]. Additionally, It has been shown experimentally that hippocampal theta sequences, generated during active exploration of the environment, play a crucial role in selecting appropriate actions in goal-directed tasks[3,4]. Howeve

Creating place fields in place cells is crucial for forming spatially dependent episodic memories in the brain, with the hippocampus playing a central role. Specifically, we focus on CA1 pyramidal neurons, which receive inputs from the CA3 and entorhinal cortex (EC). No widely accepted network-based theory for place field formation exists, but many models offer mechanisms for place-field firing. One type of hypotheses proposes that it results from summated output of spatially tuned cells, like grid cells or boundary vector cells. Another suggests CA1 place fields are replicate of CA3 place fie

In many neurological disorders, sleep disturbances and intellectual disability are strongly associated.Therefore, by studying these types of disorders, we can attempt to elucidate molecular and cellularmechanisms with broad relevance to brain function and disease. Christianson syndrome (CS) is anexample of a monogenic condition involving X-linked intellectual disability and sleep disturbances.The lack of treatment options for these children is directly related to our poor understanding of themechanisms underlying the disease. CS arises from mutations in the SLC9A6 gene which encodes theendosom

…a population of hippocampal pyramidal cells (PCs), some of which display spatially tuned firing (place cells). When an animal enters a novel environment, new spatially tuned firing (place fields: PFs) of PCs emerges. Place field formation in CA1 PCs has been proposed to rely on a well-established cellular mechanism called behavioural timescale synaptic plasticity (BTSP). During BTSP, a single occurrence of a long postsynaptic dendritic plateau potential and resulti

Cognitive decline after multiple brain-wide microstrokes is reported regularly in patients diagnosed with vascular dementia. However, the neuropathological mechanisms linking microstrokes to cognitive decline remain unclear, with no specific treatment options available. We present a mouse model to study hippocampal memory circuits in the healthy condition and after induction of cerebral microstrokes via microsphere injections. Mice are trained to navigate a virtual corridor while recording the same hippocampal neurons via chronic 2-photon calcium imaging before and after stroke for up to six w

Place Cells (PCs), are neurons that exhibit localized firing when an animal enters specific areas within an environment. Despite extensive experimental study revealing their link to cognitive functions, the precise cellular mechanisms underlying the transformation of a hippocampal neuron into a Place Cell remain incompletely understood. In our research, we employed a detailed computational model of a CA1 pyramidal neuron, considering both its morphology and biophysics. We aimed to elucidate how, and under what circumstances, such a neuron could encode a specific location based on the self-orga

Hippocampal pyramidal cells (PCs) express spatially tuned activity (i.e., ‘place cells’ exhibiting ‘place fields’, PF) to support navigation. However, the cellular mechanisms of novel PF formation are elusive. Behavioral time scale synaptic plasticity (BTSP), recently described in mouse CA1PCs, is a putative mechanism of PF formation (Bittner et al., 2015). It starts with a silent PC exhibiting a large Ca2+ plateau in dendrites accompanied by somatic bursting, which initiates the emergence of tuning near the location of induction. Consequently, activity is strongest during formation and lower

…place cells, replay).In order to u

…which has been modeled with place-cell-based models. However, traditional models usually ignore detailed trajectories or kinematics. Here we extended a place cell-based reinforcement learning model to include detailed kinematics and used it to investigate the role of motivational stress. We performed experiments with two strains of mi

…information through the presence of place cells (PC) which are tuned to specific locations in space. As a population, PCs form a “cognitive map” of the environment that adapts to contextual changes through remapping. The dorsal and ventral parts of the hippocampus have different functional implications in spatial coding. While the dorsal HPC mainly processes spatial information, the ventral HPC encodes valence an

Stable neural ensembles are often thought to underlie stable learned behaviors and memory. Recent longitudinal experiments, however, that tracked the activity of the same neurons over days to weeks have shown that neuronal activity patterns can change over extended timescales even if behaviors remain the same – a phenomenon termed representational drift. Here we test whether neural circuit remodeling (defined as any change in structural connectivity) contributes to representational drift. To do this, we tracked how hippocampal CA1 spatial representations of a familiar environment change with t