Engram neurons: Encoding, consolidation, retrieval, and forgetting of memory

Molecular Psychiatry, Journal Year: 2023, Volume and Issue: 28(8), P. 3207 - 3219

Published: June 27, 2023

Tremendous strides have been made in our understanding of the neurobiological substrates memory - so-called "engram". Here, we integrate recent progress engram field to illustrate how neurons transform across "lifespan" a from initial encoding, consolidation and retrieval, ultimately forgetting. To do so, first describe cell-intrinsic properties shape emergence at encoding. Second, highlight these encoding preferentially participate synaptic- systems-level memory. Third, changes during guide neural reactivation facilitate recall. Fourth, mechanisms forgetting, can counteract established consolidation, retrieval. Motivated by experimental results four sections, conclude proposing some conceptual extensions traditional view engram, including broadening cell-type participation within engrams stages. In collection, review synthesizes general principles stages, describes future avenues further understand dynamic engram.

Language: Английский

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A retinotopic code structures the interaction between perception and memory systems

Nature Neuroscience, Journal Year: 2024, Volume and Issue: 27(2), P. 339 - 347

Published: Jan. 2, 2024

Language: Английский

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Influencing dreams through sensory stimulation: A systematic review

Sleep Medicine Reviews, Journal Year: 2024, Volume and Issue: 74, P. 101908 - 101908

Published: Feb. 15, 2024

Sleep is typically considered a state of disconnection from the environment, yet instances external sensory stimuli influencing dreams have been reported for centuries. Explaining this phenomenon could provide valuable insight into dreams' generative and functional mechanisms, factors that promote sleep continuity, processes underlie conscious awareness. Moreover, harnessing dream engineering benefit individuals suffering dream-related alterations. This PRISMA-compliant systematic review assessed current evidence concerning influence stimulation on mentation. We included 51 publications, which 21 focused auditory stimulation, ten somatosensory eight olfactory four visual two vestibular one multimodal stimulation. Furthermore, nine references explored conditioned associative stimulation: six targeted memory reactivation protocols three lucid protocols. The frequency stimulus-dependent changes across studies ranged 0 to ∼80%, likely reflecting considerable heterogeneity definitions methodological approaches. Our findings highlight lack comprehensive understanding functions, neurophysiological correlates changes. suggest paradigm shift required meaningful progress in field.

Language: Английский

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Quantifying aphantasia through drawing: Those without visual imagery show deficits in object but not spatial memory

Cortex, Journal Year: 2020, Volume and Issue: 135, P. 159 - 172

Published: Dec. 4, 2020

Language: Английский

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Perception and memory have distinct spatial tuning properties in human visual cortex

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Oct. 18, 2022

Abstract Reactivation of earlier perceptual activity is thought to underlie long-term memory recall. Despite evidence for this view, it unclear whether mnemonic exhibits the same tuning properties as feedforward activity. Here, we leverage population receptive field models parameterize fMRI in human visual cortex during spatial retrieval. Though retinotopic organization present both perception and memory, large systematic differences are also evident. Whereas there a three-fold decline precision from early late areas perception, pattern not observed This difference cannot be explained by reduced signal-to-noise or poor performance on trials. Instead, simulating top-down network model cortex, demonstrate that property well hierarchical structure system. Together, modeling empirical results suggest computational constraints imposed system architecture limit fidelity reactivation sensory cortex.

Language: Английский

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Scene Perception and Visuospatial Memory Converge at the Anterior Edge of Visually Responsive Cortex

Journal of Neuroscience, Journal Year: 2023, Volume and Issue: 43(31), P. 5723 - 5737

Published: July 20, 2023

To fluidly engage with the world, our brains must simultaneously represent both scene in front of us and memory immediate surrounding environment (i.e., local visuospatial context). How does brain's functional architecture enable sensory mnemonic representations to closely interface while also avoiding sensory-mnemonic interference? Here, we asked this question using first-person, head-mounted virtual reality fMRI. Using reality, human participants sexes learned a set immersive, real-world environments which systematically manipulated extent context associated image across three learning conditions, spanning from single FOV city street. We used individualized, within-subject fMRI determine brain areas support during recall (Experiment 1) recognition 2). Across whole brain, activity patches cortex was modulated by amount known context, each located immediately anterior one perception high-level visual cortex. Individual subject analyses revealed that these corresponded functionally defined place areas, selectively respond when visually recalling personally familiar places. In addition showing levels were multivariate showed represented identity specific being recalled. Together, results suggest convergence zone for at edge

Language: Английский

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Replay-triggered brain-wide activation in humans

Nature Communications, Journal Year: 2024, Volume and Issue: 15(1)

Published: Aug. 21, 2024

The consolidation of discrete experiences into a coherent narrative shapes the cognitive map, providing structured mental representations our experiences. In this process, past memories are reactivated and replayed in sequence, fostering hippocampal-cortical dialogue. However, brain-wide engagement coinciding with sequential reactivation (or replay) remains largely unexplored. study, employing simultaneous EEG-fMRI, we capture both spatial temporal dynamics memory replay. We find that during simulation, fast sequences as detected via EEG. These transient replay events associated heightened fMRI activity hippocampus medial prefrontal cortex. Replay occurrence strengthens functional connectivity between default mode network, set brain regions key to representing map. On other hand, when subjects at rest following learning, task-related items is stronger than pre-learning rest, also hippocampal activation augmented entorhinal Together, findings highlight distributed, its This study uses EEG-fMRI investigate how replays experiences, revealing by EEG correspond increased enhanced network fMRI.

Language: Английский

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Topography of scene memory and perception activity in posterior cortex – a publicly available resource

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 6, 2025

Adaptive behavior in complex environments requires integrating visual perception with memory of our spatial environment. Recent work has implicated three brain areas posterior cerebral cortex - the place (PMAs) that are anterior to scene (SPAs) this function. However, PMAs' relationship broader cortical hierarchy remains unclear due limited group-level characterization. Here, we examined PMA and SPA locations across fMRI datasets (44 participants, 29 female). SPAs were identified using a standard localizer where participants viewed scenes versus faces. PMAs by contrasting activity when recalled personally familiar places faces (Datasets 1-2) or multiple categories (familiar faces, bodies, objects, famous faces; Dataset 3). Across datasets, located on ventral lateral surfaces. The displacement between was highly reproducible. Compared public atlases, fell at boundary externally-oriented networks (dorsal attention) internally-oriented (default mode). Additionally, while overlapped retinotopic maps, consistently mapped cortex. These results establish anatomical position inflection points along unimodal sensory transmodal, apical regions, which informs theories how integrates for scenes. We have released probabilistic parcels these regions facilitate future research into their roles cognition. Complex dynamic interplay mnemonic perceptual information. For example, navigation representation current its surrounding visuospatial context. suggested areas, cortex, well-positioned serve role. large group show robustly localizable, interface distributed is uniquely suited mnemonic-perceptual integration. regions-of-interest localization procedure so others can identify own participants.

Language: Английский

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Transformative neural representations support long-term episodic memory

Science Advances, Journal Year: 2021, Volume and Issue: 7(41)

Published: Oct. 8, 2021

Memory is often conceived as a dynamic process that involves substantial transformations of mental representations. However, the neural mechanisms underlying these and their role in memory formation retrieval have only started to be elucidated. Combining intracranial EEG recordings with deep network models, we provide detailed picture representational from encoding short-term maintenance long-term underlie successful episodic memory. We observed during encoding. Critically, more pronounced semantic formats predicted better subsequent memory, this effect was mediated by consistent item-specific representations across events. The were further transformed right after stimulus offset, similar those than Our results suggest pass through multiple stages achieve recall.

Language: Английский

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Neural representations of naturalistic events are updated as our understanding of the past changes

eLife, Journal Year: 2022, Volume and Issue: 11

Published: Dec. 15, 2022

The brain actively reshapes our understanding of past events in light new incoming information. In the current study, we ask how supports this updating process during encoding and recall naturalistic stimuli. One group participants watched a movie (‘The Sixth Sense’) with cinematic ‘twist’ at end that dramatically changed interpretation previous events. Next, were asked to verbally events, taking into account Most updated their incorporate twist. Two additional groups recalled without having update memories recall: one never saw twist; another was exposed twist prior beginning movie, thus information incorporated both recall. We found providing about beforehand altered neural response patterns movie-viewing default mode network (DMN). Moreover, presenting representation previously-encoded subset DMN regions. Further evidence for transformation obtained by comparing activation correlating them behavioral signatures memory updating. Our results demonstrate representations encoded are dynamically integrated natural contexts.

Language: Английский

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