Toolkit/double retrograde tracing

double retrograde tracing

Assay Method·Research·Since 2017

Taxonomy: Technique Branch / Method. Workflows sit above the mechanism and technique branches rather than replacing them.

Summary

double retrograde tracing demonstrated that LS- and mPFC-projecting cells represent two largely anatomically distinct cell groups

Usefulness & Problems

Why this is useful

Double retrograde tracing was used to determine whether ventral hippocampal neurons projecting to LS and mPFC belong to overlapping or distinct populations. The abstract reports that these groups were largely anatomically distinct.; anatomical comparison of projection-defined neuron populations; testing whether two projection-defined cell groups overlap

Source:

Double retrograde tracing was used to determine whether ventral hippocampal neurons projecting to LS and mPFC belong to overlapping or distinct populations. The abstract reports that these groups were largely anatomically distinct.

Source:

anatomical comparison of projection-defined neuron populations

Source:

testing whether two projection-defined cell groups overlap

Problem solved

It addresses whether opposing behavioral effects could arise from separate projection-defined cell populations.; distinguishes whether LS-projecting and mPFC-projecting vHPC neurons are anatomically distinct

Source:

It addresses whether opposing behavioral effects could arise from separate projection-defined cell populations.

Source:

distinguishes whether LS-projecting and mPFC-projecting vHPC neurons are anatomically distinct

Problem links

distinguishes whether LS-projecting and mPFC-projecting vHPC neurons are anatomically distinct

Literature

It addresses whether opposing behavioral effects could arise from separate projection-defined cell populations.

Source:

It addresses whether opposing behavioral effects could arise from separate projection-defined cell populations.

Published Workflows

Bidirectional Control of Anxiety-Related Behaviors in Mice: Role of Inputs Arising from the Ventral Hippocampus to the Lateral Septum and Medial Prefrontal Cortex

2017

Objective: To directly compare the behavioral contribution of ventral hippocampal neurons projecting to the lateral septum versus the medial prefrontal cortex in anxiety-related behavior.

Why it works: The workflow uses retrograde Cre delivery from LS or mPFC together with Cre-responsive AAV effectors in vHPC so that chemogenetic manipulation is restricted to neurons defined by their projection target, enabling causal comparison of the two pathways.

activation or inhibition of projection-defined ventral hippocampal neuron populationscomparison of LS-projecting versus mPFC-projecting ventral hippocampal pathwaysretrograde viral targetingCre-dependent chemogeneticsbehavioral anxiety testingdouble retrograde tracing

Stages

  1. 1.
    Projection-targeted viral access to vHPC neurons(library_build)

    This stage creates pathway-specific access to ventral hippocampal neurons defined by their downstream target.

    Selection: Target LS-projecting or mPFC-projecting ventral hippocampal cells using retrograde Cre from the projection target and Cre-responsive AAV in vHPC.

  2. 2.
    Behavioral testing after chemogenetic manipulation(confirmatory_validation)

    This stage tests whether pathway-specific manipulation changes anxiety-related behavior.

    Selection: Assess consequences of manipulating targeted neurons in well-established tests of anxiety.

  3. 3.
    Anatomical distinction of projection-defined populations(secondary_characterization)

    This stage provides anatomical context for interpreting opposite behavioral effects of the two projection-defined groups.

    Selection: Use double retrograde tracing to determine whether LS-projecting and mPFC-projecting cells are distinct populations.

Steps

  1. 1.
    Inject retrograde Cre virus into LS or mPFCretrograde targeting reagent

    To mark ventral hippocampal neurons by their projection target.

    Retrograde Cre delivery must occur to define the target cell population before Cre-dependent effector expression in vHPC can be restricted to those neurons.

  2. 2.
    Inject Cre-responsive AAV DREADD vector into vHPCCre-dependent chemogenetic effector vector

    To express activating or inhibitory chemogenetic effectors in the projection-defined ventral hippocampal neurons.

    This step follows the projection-targeting logic so that effector expression is restricted to cells that received Cre from the retrograde virus.

  3. 3.
    Examine behavioral consequences in anxiety tests

    To determine how manipulation of LS-projecting or mPFC-projecting vHPC neurons affects anxiety-related behavior.

    Behavioral testing is performed after pathway-specific effector targeting so the causal effect of manipulating each projection-defined population can be measured.

  4. 4.
    Perform double retrograde tracing to compare LS- and mPFC-projecting cellsanatomical mapping assay

    To determine whether LS-projecting and mPFC-projecting ventral hippocampal neurons are anatomically distinct populations.

    This anatomical characterization helps interpret the opposing behavioral effects observed in the prior behavioral testing stage.

Taxonomy & Function

Primary hierarchy

Technique Branch

Method: A concrete measurement method used to characterize an engineered system.

Target processes

No target processes tagged yet.

Implementation Constraints

cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationoperating role: sensor

It requires retrograde tracing from both LS and mPFC. The abstract does not provide further protocol detail.; requires retrograde tracing from both target regions

The abstract does not indicate that this method alone establishes causal function; it provides anatomical segregation evidence.; the abstract supports anatomical distinction but not finer cellular or molecular characterization

Validation

Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication

Supporting Sources

Ranked Claims

Claim 1anatomical distinctionsupports2017Source 1needs review

LS-projecting and mPFC-projecting ventral hippocampal cells are largely anatomically distinct cell groups.

double retrograde tracing demonstrated that LS- and mPFC-projecting cells represent two largely anatomically distinct cell groups
Claim 2behavioral effectsupports2017Source 1needs review

Activation of LS-projecting ventral hippocampal cells decreased anxiety, whereas inhibition of these cells promoted anxiety.

Chemogenetic manipulation of LS-projecting vHPC cells led to bidirectional changes in anxiety: activation of LS-projecting vHPC cells decreased anxiety whereas inhibition of these cells produced opposite anxiety-promoting effects.
Claim 3behavioral effectsupports2017Source 1needs review

mPFC-projecting ventral hippocampal cells promoted anxiety.

The observed anxiety-reducing function of LS-projecting cells was in contrast with the function of mPFC-projecting cells, which promoted anxiety.

Approval Evidence

1 source1 linked approval claimfirst-pass slug double-retrograde-tracing
double retrograde tracing demonstrated that LS- and mPFC-projecting cells represent two largely anatomically distinct cell groups

Source:

anatomical distinctionsupports

LS-projecting and mPFC-projecting ventral hippocampal cells are largely anatomically distinct cell groups.

double retrograde tracing demonstrated that LS- and mPFC-projecting cells represent two largely anatomically distinct cell groups

Source:

Comparisons

Source-stated alternatives

The abstract does not name an alternative anatomical mapping method.

Source:

The abstract does not name an alternative anatomical mapping method.

Source-backed strengths

provides anatomical evidence supporting separation of projection-defined populations

Source:

provides anatomical evidence supporting separation of projection-defined populations

Compared with Langendorff perfused heart electrical recordings

double retrograde tracing 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

double retrograde tracing 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.

Compared with sub-picosecond pump-probe analysis of bacteriorhodopsin pigments

double retrograde tracing 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. 1.
    StructuralSource 1Neuropsychopharmacology2017Claim 1Claim 2Claim 3

    Extracted from this source document.