Source 1primary paper2025MED
Toolkit/AAV2-hSyn-hM3Dq-mCherry
AAV2-hSyn-hM3Dq-mCherry
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
AAV2-hSyn-hM3Dq-mCherry, a viral vector that has been shown to preferentially transduce LDAFs
Usefulness & Problems
Why this is useful
This viral construct delivers hM3Dq-mCherry under the hSyn promoter and is used to preferentially transduce large diameter afferent fibers in the rat SCI model.; preferential transduction of large diameter afferent fibers; delivery of hM3Dq chemogenetic actuator to DRG afferents
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This viral construct delivers hM3Dq-mCherry under the hSyn promoter and is used to preferentially transduce large diameter afferent fibers in the rat SCI model.
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preferential transduction of large diameter afferent fibers
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delivery of hM3Dq chemogenetic actuator to DRG afferents
Problem solved
It enables targeted delivery of the chemogenetic actuator to the afferent population the study aims to modulate.; provides a delivery construct for targeted chemogenetic excitation of large afferent fibers
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It enables targeted delivery of the chemogenetic actuator to the afferent population the study aims to modulate.
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provides a delivery construct for targeted chemogenetic excitation of large afferent fibers
Problem links
provides a delivery construct for targeted chemogenetic excitation of large afferent fibers
LiteratureIt enables targeted delivery of the chemogenetic actuator to the afferent population the study aims to modulate.
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It enables targeted delivery of the chemogenetic actuator to the afferent population the study aims to modulate.
Published Workflows
Objective: Use targeted chemogenetic afferent neuromodulation with treadmill rehabilitation in a rat contusion SCI model to probe locomotor recovery in a manner similar to epidural electrical stimulation while enabling targeted manipulation and detailed kinematic quantification.
Why it works: The authors frame the workflow as similar to EES but with genetic tools and an animal model that allow targeted manipulation, precise quantification of manipulated cells and circuits, and extensive kinematic data collection.
increase excitability of large diameter afferent fibersafferent neuromodulation during recoveryviral deliverydesigner-drug chemogenetic activationtreadmill rehabilitationlongitudinal kinematic analysismixed effects modeling
Stages
- 1.Vector delivery to afferents(library_build)
This stage establishes the targeted chemogenetic or control condition in the rat contusion SCI model before recovery-phase activation and measurement.
Selection: Deliver hM3Dq DREADD or tracer-only control by direct intraganglionic injection using vectors reported to preferentially transduce large diameter afferent fibers.
- 2.Chemogenetic activation during rehabilitation(functional_characterization)
This stage applies the intended neuromodulatory perturbation during rehabilitation so its effect on locomotor recovery can be measured.
Selection: Increase activity of transduced neurons by CNO application during treadmill training in the recovery phase.
- 3.Longitudinal kinematic measurement and modeling(confirmatory_validation)
The authors state that locomotor changes with afferent stimulation can be subtle, so detailed kinematic characterization is needed to detect treatment effects over time and speed.
Selection: Collect treadmill kinematic data across speeds over nine weeks and analyze treatment, time, and speed effects using mixed-effects models.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Techniques
Computational DesignTarget processes
recombinationInput: Chemical
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: payload burdenoperating role: sensor
The construct is administered by direct intraganglionic injection in adult Long-Evans rats and is paired with CNO administration to activate the encoded DREADD.; requires direct intraganglionic injection; requires CNO for downstream activation of the encoded DREADD
The abstract does not establish perfect cell-type specificity or broad applicability beyond the reported rat intraganglionic delivery context.; selectivity is described as preferential rather than absolute
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Mixed-effects modeling identified significant treatment effects and treatment interactions in many kinematic parameters, with dependence on speed.
Significant effects of treatment and treatment interactions were found in many parameters, with a sometimes complicated dependence on speed.
DREADDs activation generally resulted in shorter stance duration, less reduction in swing duration with speed, and lower duty factors during treadmill locomotion after contusion SCI.
Generally, DREADDs activation resulted in shorter stance duration, but less reduction in swing duration with speed, yielding lower duty factors.
The study used hM3Dq DREADD delivered by AAV2-hSyn-hM3Dq-mCherry to increase excitability of large diameter afferent fibers in the rat contusion spinal cord injury model.
We used a viral construct that selectively transduces large diameter afferent fibers (LDAFs) with a designer receptor exclusively activated by a designer drug (hM3Dq DREADD; a chemogenetic construct) to increase the excitability of large fibers specifically, in the rat contusion SCI model.
Withdrawal of DREADDs activation in week seven did not cause significant changes in kinematics, suggesting diminished late-stage effects.
withdrawal of DREADDs activation in week seven did not cause significant changes in kinematics, suggesting that activation may have dwindling effects at this later stage.
High-resolution kinematics is useful for detecting subtle changes during recovery with afferent neuromodulation after spinal cord injury.
This study highlights the utility of high-resolution kinematics for detecting subtle changes during recovery
Approval Evidence
1 source1 linked approval claimfirst-pass slug aav2-hsyn-hm3dq-mcherry
AAV2-hSyn-hM3Dq-mCherry, a viral vector that has been shown to preferentially transduce LDAFs
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mechanism or functionsupports
The study used hM3Dq DREADD delivered by AAV2-hSyn-hM3Dq-mCherry to increase excitability of large diameter afferent fibers in the rat contusion spinal cord injury model.
We used a viral construct that selectively transduces large diameter afferent fibers (LDAFs) with a designer receptor exclusively activated by a designer drug (hM3Dq DREADD; a chemogenetic construct) to increase the excitability of large fibers specifically, in the rat contusion SCI model.
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Comparisons
Source-stated alternatives
The paper explicitly uses AAV2-hSyn-mCherry as a control construct and frames the overall strategy against epidural electrical stimulation as a comparator paradigm.
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The paper explicitly uses AAV2-hSyn-mCherry as a control construct and frames the overall strategy against epidural electrical stimulation as a comparator paradigm.
Source-backed strengths
reported to preferentially transduce large diameter afferent fibers
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reported to preferentially transduce large diameter afferent fibers
Compared with electrical stimulation
The paper explicitly uses AAV2-hSyn-mCherry as a control construct and frames the overall strategy against epidural electrical stimulation as a comparator paradigm.
Shared frame: source-stated alternative in extracted literature
Strengths here: reported to preferentially transduce large diameter afferent fibers.
Relative tradeoffs: selectivity is described as preferential rather than absolute.
Source:
The paper explicitly uses AAV2-hSyn-mCherry as a control construct and frames the overall strategy against epidural electrical stimulation as a comparator paradigm.
Ranked Citations
- 1.