Source 1primary paper2022Nature Communications
Toolkit/engram index
engram index
Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
The mapping was aided by an engram index, which identified 117 cFos+ brain regions holding engrams with high probability
Usefulness & Problems
Why this is useful
The engram index is used to aid mapping of the engram complex by identifying cFos+ brain regions with high probability of holding engrams. In this study it supported prioritization across 247 regions.; prioritizing brain regions likely to hold engrams; assisting brain-wide mapping of contextual fear conditioning memory
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The engram index is used to aid mapping of the engram complex by identifying cFos+ brain regions with high probability of holding engrams. In this study it supported prioritization across 247 regions.
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prioritizing brain regions likely to hold engrams
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assisting brain-wide mapping of contextual fear conditioning memory
Problem solved
It helps reduce a large brain-wide search space to a subset of regions more likely to contain memory engrams.; helps identify high-probability engram-containing regions from brain-wide phenotyping data
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It helps reduce a large brain-wide search space to a subset of regions more likely to contain memory engrams.
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helps identify high-probability engram-containing regions from brain-wide phenotyping data
Problem links
helps identify high-probability engram-containing regions from brain-wide phenotyping data
LiteratureIt helps reduce a large brain-wide search space to a subset of regions more likely to contain memory engrams.
Source:
It helps reduce a large brain-wide search space to a subset of regions more likely to contain memory engrams.
Published Workflows
Objective: Map a distributed engram complex for contextual fear conditioning memory across the mouse brain and test whether distributed engram ensembles are functionally connected and jointly contribute to memory recall.
Why it works: The workflow combines brain-wide phenotyping to identify candidate engram-containing regions with causal perturbation experiments to test whether those ensembles are functionally connected and contribute to recall.
distributed storage of a single memory across multiple functionally connected brain regionsreactivation of neuronal ensembles during recalltissue phenotypingengram index prioritizationoptogenetic manipulationchemogenetic reactivation
Stages
- 1.Brain-wide tissue phenotyping(broad_screen)
This stage provides a brain-wide map and narrows many assayed regions to a smaller set of candidate engram regions.
Selection: encoding activated neuronal ensembles characterized across regions and prioritized with an engram index
- 2.Recall reactivation assessment(secondary_characterization)
This stage adds evidence that candidate ensembles are reactivated during recall rather than only during encoding.
Selection: brain-wide reactivation of candidate neuronal ensembles by recall
- 3.Optogenetic functional interrogation(functional_characterization)
This stage tests whether mapped candidate ensembles are functionally connected to known hippocampal or amygdala engrams.
Selection: optogenetic manipulation to reveal engram ensembles and their functional connections
- 4.Chemogenetic multi-ensemble recall test(confirmatory_validation)
This stage tests whether coordinated reactivation of multiple engram ensembles better reflects natural recall than reactivation of a single ensemble.
Selection: comparison of memory recall after simultaneous multi-ensemble versus single-ensemble chemogenetic reactivation
Taxonomy & Function
Primary hierarchy
Technique Branch
Method: A concrete measurement method used to characterize an engineered system.
Techniques
Functional AssayTarget processes
No target processes tagged yet.
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: sensor
Its use depends on brain-wide tissue phenotyping and cFos-based regional measurements in mice.; requires tissue phenotyping data across brain regions
the abstract does not define how the index is calculated
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Simultaneous chemogenetic reactivation of multiple engram ensembles produced greater memory recall than reactivation of a single engram ensemble.
Simultaneous chemogenetic reactivation of multiple engram ensembles conferred a greater level of memory recall than reactivation of a single engram ensemble
The engram index identified 117 cFos+ brain regions with high probability of holding engrams.
The mapping was aided by an engram index, which identified 117 cFos+ brain regions holding engrams with high probability
regions identified with high engram probability 117 regions
Approval Evidence
1 source1 linked approval claimfirst-pass slug engram-index
The mapping was aided by an engram index, which identified 117 cFos+ brain regions holding engrams with high probability
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screening or prioritization resultsupports
The engram index identified 117 cFos+ brain regions with high probability of holding engrams.
The mapping was aided by an engram index, which identified 117 cFos+ brain regions holding engrams with high probability
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Comparisons
Source-backed strengths
supports large-scale prioritization across many brain regions
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supports large-scale prioritization across many brain regions
Compared with Langendorff perfused heart electrical recordings
engram index and Langendorff perfused heart electrical recordings address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
Compared with native green gel system
engram index and native green gel system address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
engram index and sub-picosecond pump-probe analysis of bacteriorhodopsin pigments address a similar problem space.
Shared frame: same top-level item type
Strengths here: looks easier to implement in practice.
Ranked Citations
- 1.