genetically encoded voltage indicators

Stages

1. 1.
   classify signal degradation sources(decision_gate)

   The review first systematizes limitation classes so that later mitigation strategies can be matched to the underlying source of degraded signal quality.

   Selection: Identify whether limitations arise from photon shot noise, device-related errors, or sample-related measurement errors.

2. 2.
   choose acquisition-side mitigation strategies(functional_characterization)

   The abstract explicitly groups acquisition-side interventions as available mitigation strategies for improving imaging quality.

   Selection: Apply hardware optimization, sensor choice, sample preparation, and experimental design strategies appropriate to the identified limitation class.

3. 3.
   apply post-processing and computational correction(secondary_characterization)

   The abstract lists post-processing and computational correction after hardware, sensor, and experimental-design choices, implying a later-stage correction role.

   Selection: Use post-processing and computational correction methods to further improve data quality after acquisition-side choices.

Stages

1. 1.
   Kir perturbation across neutrophil chemotaxis models(broad_screen)

   This stage tests whether inwardly rectifying potassium channels are required for directional sensing in neutrophils across multiple models.

   Selection: disruption of directional sensing toward different chemoattractants after Kir blocking or knockout

2. 2.
   Voltage imaging during zebrafish neutrophil chemotaxis(functional_characterization)

   This stage characterizes how membrane potential changes during neutrophil migration and whether Kir7.1 is required for depolarization toward the chemokine source.

3. 3.
   Optogenetic causal perturbation of membrane potential(confirmatory_validation)

   This stage tests whether imposed membrane-potential changes can directly bias pseudopod selection, trigger protrusions, or stall migration.

   Selection: behavioral response to focal depolarization or global hyperpolarization

4. 4.
   GPCR signaling analysis in dHL-60 cells(secondary_characterization)

   This stage extends the migration findings to a signaling readout in a neutrophil-like cell model.

Steps

1. 1.
   Block or knock out inwardly rectifying potassium channels in neutrophils

   Test whether Kir activity is necessary for directional sensing during chemotaxis.

   Necessity testing provides an initial functional readout before deeper mechanistic characterization.

2. 2.
   Image membrane potential dynamics with genetically encoded voltage indicators in zebrafish neutrophilsassay readout

   Measure endogenous membrane-potential changes during chemotaxis and relate them to cell behavior.

   After establishing that Kir perturbation affects directional sensing, voltage imaging reveals the dynamic membrane-potential states associated with migration.

3. 3.
   Apply focal optogenetic depolarization to bias protrusion selectioncausal perturbation method

   Test whether local depolarization is sufficient to bias pseudopod selection and trigger new protrusions.

   This follows observational voltage imaging to move from correlation to causal sufficiency testing.

4. 4.
   Apply global hyperpolarization to test effects on migration progressioncausal perturbation method

   Test whether whole-cell hyperpolarization inhibits ongoing migration.

   A global perturbation complements focal depolarization by testing whether broad voltage shifts suppress motility rather than redirect it.

5. 5.
   Assess GPCR signaling activation in dHL-60 cells under Kir-related conditions

   Link Kir function to GPCR signaling activation in a neutrophil-like cell model.

   This step provides signaling-level mechanistic support after behavioral and voltage-perturbation observations.

Stages

1. 1.
   ThUS-mediated BBB opening and payload delivery(functional_characterization)

   This stage exists to replace invasive, highly focal surgical introduction of magnetogenetic components with a non-invasive delivery route through transient BBB opening.

   Selection: Use theranostic ultrasound to transiently open the BBB and deliver SPIONs plus viral vectors encoding thermoreceptors and GEVIs non-invasively.

2. 2.
   MOVE pulse sequence expansion of opening volume(secondary_characterization)

   This stage exists to enlarge the volume of BBB opening during one treatment so that gene delivery can be increased and expression can extend across larger brain regions.

   Selection: Apply the MOVE pulse sequence to maximize BBB opening volume within a single ThUS treatment.

Steps

1. 1.
   Transiently open the BBB with theranostic ultrasounddelivery platform

   Create non-invasive access for delivery of magnetogenetic components to the brain.

   BBB opening is required before non-invasive delivery of SPIONs and viral vectors can occur.

2. 2.
   Deliver SPIONs and viral vectors encoding thermoreceptors and GEVIs non-invasivelydelivery-enabling platform

   Introduce the components needed for remote magnetogenetic modulation and fluorescence-based monitoring.

   Payload delivery follows BBB opening because the opening facilitates non-invasive entry of nanoparticles and viral vectors into the brain.

3. 3.
   Apply the MOVE pulse sequence across multiple targeted focal zonespulse-sequence component

   Maximize BBB opening volume within a single ThUS treatment.

   After establishing ThUS-enabled delivery, the workflow expands opening volume to improve delivery extent and expression breadth within the same treatment session.

4. 4.
   Assess delivery gain and expression breadth after MOVEintervention being evaluated

   Determine whether expanded opening volume improves gene delivery and expression coverage.

   Outcome assessment follows MOVE application to test whether the expanded opening strategy produces the intended delivery benefits.

Stages

1. 1.
   sensor optimization(functional_characterization)

   The review uses GCaMP as an example to discuss established sensor optimization pipelines.

2. 2.
   gene delivery planning(decision_gate)

   The review identifies gene delivery approaches as a practical consideration for end users of GINAs.

3. 3.
   imaging system setup(confirmatory_validation)

   The review highlights imaging system requirements as a practical determinant of successful GINA use.

4. 4.
   data analysis(secondary_characterization)

   The review explicitly includes data analysis techniques among practical methods for end users.