The homogenous hippocampus: How hippocampal cells process available and potential goals

Progress in Neurobiology, Год журнала: 2024, Номер 240, С. 102653 - 102653

Опубликована: Июль 2, 2024

We present here a view of the firing patterns hippocampal cells that is contrary, both functionally and anatomically, to conventional wisdom. argue hippocampus responds efference copies goals encoded elsewhere; it uses these detect resolve conflict or interference between in general. While can involve space, do not encode spatial (or other special types of) memory, as such. also transverse circuits operate an essentially homogeneous way along its length. The apparently different functions parts (e.g. memory retrieval versus anxiety) result from (situational/motivational) inputs on which those perform same fundamental computational operations. On this view, key role iterative adjustment, via Papez-like circuits, synaptic weights cell assemblies elsewhere.

Язык: Английский

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Single neurons in the human medial temporal lobe flexibly shift representations across spatial and memory tasks

Hippocampus, Год журнала: 2023, Номер 33(5), С. 600 - 615

Опубликована: Апрель 15, 2023

Investigations into how individual neurons encode behavioral variables of interest have revealed specific representations in single neurons, such as place and object cells, well a wide range cells with conjunctive encodings or mixed selectivity. However, most experiments examine neural activity within tasks, it is currently unclear if change across different task contexts. Within this discussion, the medial temporal lobe particularly salient, known to be important for multiple behaviors including spatial navigation memory, however relationship between these functions unclear. Here, investigate vary contexts lobe, we collected analyzed single-neuron from human participants they completed paired-task session consisting passive-viewing visual working memory task. Five patients contributed 22 sessions, which were spike sorted together allow same putative compared tasks. each task, replicated concept-related activations target-location serial-position responsive When comparing neuronal first established that significant number maintained kind representation, responding stimuli presentations Further, found changed nature their representation stimulus responded serial position Overall, our results support flexible encoding multiple, distinct aspects tasks by whereby some feature coding

Язык: Английский

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Learning produces a hippocampal cognitive map in the form of an orthogonalized state machine

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Авг. 6, 2023

ABSTRACT Cognitive maps confer animals with flexible intelligence by representing spatial, temporal, and abstract relationships that can be used to shape thought, planning, behavior. have been observed in the hippocampus, but their algorithmic form processes which they are learned remain obscure. Here, we employed large-scale, longitudinal two-photon calcium imaging record activity from thousands of neurons CA1 region hippocampus while mice efficiently collect rewards two subtly different versions linear tracks virtual reality. The results provide a detailed view formation cognitive map hippocampus. Throughout learning, both animal behavior hippocampal neural progressed through multiple intermediate stages, gradually revealing improved task representation mirrored behavioral efficiency. learning process led progressive decorrelations initially similar within across tracks, ultimately resulting orthogonalized representations resembling state machine capturing inherent structure task. We show Hidden Markov Model (HMM) biologically plausible recurrent network trained using Hebbian capture core aspects dynamics representational activity. In contrast, gradient-based sequence models such as Long Short-Term Memory networks (LSTMs) Transformers do not naturally produce representations. further demonstrate exhibited adaptive novel settings, reflecting deployment machine. These findings shed light on mathematical maps, rules sculpt them, algorithms promote animals. work thus charts course toward deeper understanding biological offers insights developing more robust artificial intelligence.

Язык: Английский

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Latent representations in hippocampal network model co-evolve with behavioral exploration of task structure

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Янв. 23, 2024

To successfully learn real-life behavioral tasks, animals must pair actions or decisions to the task's complex structure, which can depend on abstract combinations of sensory stimuli and internal logic. The hippocampus is known develop representations this forming a so-called "cognitive map". However, precise biophysical mechanisms driving emergence task-relevant maps at population level remain unclear. We propose model in plateau-based learning single cell level, combined with reinforcement an agent, leads latent representational structures codependently evolving behavior task-specific manner. In agreement recent experimental data, we show that develops essential for task-solving (cue-dependent "splitters") while excluding irrelevant ones. Finally, our makes testable predictions concerning co-dependent interactions between split policy during their evolution.

Язык: Английский

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Working memory features are embedded in hippocampal place fields

Cell Reports, Год журнала: 2024, Номер 43(3), С. 113807 - 113807

Опубликована: Фев. 23, 2024

Hippocampal principal neurons display both spatial tuning properties and memory features. Whether this distinction corresponds to separate neuron types or a context-dependent continuum has been debated. We report here that the task-context ("splitter") feature is highly variable along trial position axes. Neurons acquire lose splitter features across trials even when place field remain unaltered. Multiple fields of same can individually encode past future run trajectories, implying are under control assembly activity. Place be differentiated into subfields by behavioral choice animal, splitting within evolves trials. Interneurons also differentiate choices integrating inputs from pyramidal cells. Finally, bilateral optogenetic inactivation medial entorhinal cortex reversibly decreases fraction fields. Our findings suggest different manifestations hippocampal computation.

Язык: Английский

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Expectancy-related changes in firing of dopamine neurons depend on hippocampus

Nature Communications, Год журнала: 2024, Номер 15(1)

Опубликована: Окт. 16, 2024

The orbitofrontal cortex (OFC) and hippocampus (HC) both contribute to the cognitive maps that support flexible behavior. Previously, we used dopamine neurons measure functional role of OFC. We recorded midbrain as rats performed an odor-based choice task, in which expected rewards were manipulated across blocks. found ipsilateral OFC lesions degraded dopaminergic prediction errors, consistent with reduced resolution task states. Here have repeated this experiment male HC lesions. results show also shapes states, however unlike OFC, provides information local trial, is necessary for estimating upper-level hidden states distinguish contrast roles mapping suggest access rich from distributed regions regarding environment's structure, potentially enabling teaching signal complex behaviors.

Язык: Английский

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Perceptual-Cognitive Training Paradigms for Understanding Cognition and Cortical Visual Impairments

IntechOpen eBooks, Год журнала: 2025, Номер unknown

Опубликована: Март 11, 2025

Brain plasticity and behavioral compensation after neurological injury offer promising clinical potential for targeted functional neurorehabilitation. An active area of research in neurorehabilitation is vision restoration via perceptual learning. Despite exciting success stories, rehabilitation strategies have faced limitations achieving longevity generalization beyond the training parameters. In this chapter, we propose that learning involves more than just sensory brain regions, suggesting search neural mechanisms visual should expand system. We hypothesize engaging cognitive circuits with a navigation paradigm encoding promotes system, key input to brain’s networks. Under hypothesis, an integrated approach where systems are dynamically interacting. Furthermore, argue studying functions context necessitates controlled omission experimental paradigms, such studies implications designing effective rehabilitative patients cortical blindness. review animal on without input, focusing hippocampal formation posterior parietal cortex-brain regions thought subserve spatial navigation. Finally, explore perceptual-cognitive tasks their hypothetical address existing paradigms. Overall, identify direction developing innovative tools rehabilitate function individuals

Язык: Английский

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Hippocampal output suppresses orbitofrontal cortex schema cell formation

Nature Neuroscience, Год журнала: 2025, Номер unknown

Опубликована: Апрель 14, 2025

Abstract Both the orbitofrontal cortex (OFC) and hippocampus (HC) are implicated in formation of cognitive maps their generalization into schemas. However, how these areas interact supporting this function remains unclear, with some proposals a serial model which OFC draws on task representations created by HC to extract key behavioral features others suggesting parallel both regions construct that highlight different types information. In present study, we tested between two models asking schema correlates rat would be affected inactivating output HC, after learning during transfer across problems. We found prevalence content were unaffected one major area, ventral subiculum, learning, whereas inactivation accelerated formation. These results favor proposal operate defining

Язык: Английский

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Error-driven changes in hippocampal representations accompany flexible re-learning

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2025, Номер unknown

Опубликована: Май 21, 2025

Flexible behavior requires both the learning of new associations, and suppression previous ones, but how neural circuits achieve this balance remains unclear. Here we show that continuous changes in hippocampal representations, known as drift, may facilitate process. We used voluntary head-fixation calcium imaging to record from CA1 rats during an odor-guided navigation task required frequent re-learning. found systematic representational over course multi-hour sessions were increased following errors. A simple network model revealed such error-driven drift can enable flexible re-learning by allowing associations form patterns. consequence is are maintained latent synaptic weights. These findings reconcile apparent tension between stable memory storage, demonstrating dynamic codes could support lasting memories.

Язык: Английский

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Localized APP expression results in progressive network dysfunction by disorganizing spike timing

Neuron, Год журнала: 2023, Номер 112(1), С. 124 - 140.e6

Опубликована: Окт. 30, 2023

Progressive cognitive decline in Alzheimer's disease could either be caused by a spreading molecular pathology or an initially focal that causes aberrant neuronal activity larger network. To distinguish between these possibilities, we generated mouse model with expression of mutant human amyloid precursor protein (APP) only hippocampal CA3 cells. We found performance hippocampus-dependent memory task was impaired young adult and aged mice. In both age groups, then recorded from the CA1 region, which receives inputs APP-expressing observed theta oscillation frequency reduced along disrupted relative timing principal Highly localized limited to presynaptic cells is thus sufficient cause firing patterns postsynaptic networks, indicates progression not but also mediated progressively advancing physiological dysfunction.

Язык: Английский

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