Source 1review2019Frontiers in Physiology
Toolkit/spark cells
spark cells
Taxonomy: Mechanism Branch / Architecture. Workflows sit above the mechanism and technique branches rather than replacing them.
Summary
Expression of the chosen optogenetic tool in the cardiac cell of interest then requires, at the single-cell level, introduction of opsin-encoding genes by viral transduction, or coupling "spark cells" to primary cardiomyocytes or a stem-cell derived counterpart.
Usefulness & Problems
Why this is useful
Spark cells are presented as a coupling-based strategy for enabling optical control of cardiac cells without directly introducing the opsin gene into every target cell.; single-cell level optical control of cardiomyocytes via coupling strategy
Source:
Spark cells are presented as a coupling-based strategy for enabling optical control of cardiac cells without directly introducing the opsin gene into every target cell.
Source:
single-cell level optical control of cardiomyocytes via coupling strategy
Problem solved
It offers an alternative route to confer optical responsiveness at the single-cell level when direct viral transduction is not the only desired approach.; provides an alternative to direct gene introduction into the target cardiac cell
Source:
It offers an alternative route to confer optical responsiveness at the single-cell level when direct viral transduction is not the only desired approach.
Source:
provides an alternative to direct gene introduction into the target cardiac cell
Problem links
provides an alternative to direct gene introduction into the target cardiac cell
LiteratureIt offers an alternative route to confer optical responsiveness at the single-cell level when direct viral transduction is not the only desired approach.
Source:
It offers an alternative route to confer optical responsiveness at the single-cell level when direct viral transduction is not the only desired approach.
Published Workflows
Objective: Implement cardiac optogenetic experiments by selecting an appropriate opsin class, establishing expression in the target cardiac system, delivering light effectively, and measuring physiological or optical responses.
Why it works: The review links tool performance first to opsin biophysical properties, then to successful expression in the cardiac target, then to practical light delivery, and finally to physiological or optical readout. This ordering reflects that optical control requires both a suitable actuator and a feasible delivery-and-measurement setup.
light-gated transmembrane ion movementdepolarizationhyperpolarizationG-protein coupled intracellular signaling modulationopsin selectionviral transductionspark-cell couplingtransgenic expressionin vivo adenoviral deliverylaser illuminationLED illuminationelectrophysiological readoutoptical readout
Stages
- 1.Select optogenetic actuator class and spectral properties(library_design)
The abstract explicitly states that opsin biophysical properties determine whether stimulation or silencing will be reliable and precise, and that spectral shifts can improve penetration and combinatorial use.
Selection: Choose among depolarizing, hyperpolarizing, GPCR-signaling, and spectrally shifted optogenetic tools based on biophysical properties needed for reliable and precise stimulation or silencing.
- 2.Establish expression in the cardiac target(library_build)
The review states that expression of the chosen optogenetic tool is required before optical control can be attempted in cardiac cells or whole systems.
Selection: Introduce opsin-encoding genes by viral transduction or use spark-cell coupling at single-cell level; at system level use transgenic mice or in vivo adenoviral injection.
- 3.Deliver light to the preparation(functional_characterization)
Even with a suitable opsin and expression strategy, optical control depends on practical light delivery to the cardiac tissue.
Selection: Use laser or LED illumination with widespread or multipoint delivery appropriate to the preparation.
- 4.Measure physiological or optical responses(confirmatory_validation)
The abstract presents these readouts as the means to confirm and monitor the effects of cardiac optogenetic stimulation.
Selection: Assess responses using patch clamp, multi-unit microarray recordings, Langendorff heart electrical recordings, or optical reporters including small detecting molecules and genetically encoded sensors.
Taxonomy & Function
Primary hierarchy
Mechanism Branch
Architecture: A reusable architecture pattern for arranging parts into an engineered system.
Techniques
No technique tags yet.
Target processes
No target processes tagged yet.
Input: Light
Implementation Constraints
cofactor dependency: cofactor requirement unknownencoding mode: genetically encodedimplementation constraint: context specific validationimplementation constraint: spectral hardware requirementoperating role: sensor
This approach requires spark cells and compatible primary cardiomyocytes or stem-cell derived cardiac counterparts for coupling.; requires coupling to primary cardiomyocytes or stem-cell derived counterparts
The abstract does not establish how broadly this strategy works at system level or how it compares quantitatively with direct gene delivery.; the abstract does not specify coupling efficiency, stability, or performance limits
Validation
Cell-freeBacteriaMammalianMouseHumanTherapeuticIndep. Replication
Supporting Sources
Ranked Claims
Spectrally shifted opsin variants can support enhanced tissue penetration, combinatorial stimulation of different cell subpopulations, and all-optical read-in and read-out studies.
In cardiac physiology, optogenetics has mainly used optically controlled depolarizing ion channels to control heart rate and for optogenetic defibrillation.
Cardiac optogenetic stimulation can be read out using patch clamp, multi-unit microarray recordings, Langendorff heart electrical recordings, and optical reporters including small detecting molecules or genetically encoded sensors.
Optogenetic techniques use genetically expressed light-gated microbial channels or pumps to modulate cellular excitability with millisecond precision.
ChR2-expressing cardiomyocytes show normal baseline and active excitable membrane and Ca2+ signaling properties and are sensitive even to approximately 1 ms light pulses.
light pulse sensitivity 1 ms
Expression of the chosen optogenetic tool in cardiac cells requires gene introduction by viral transduction or coupling via spark cells at the single-cell level, and transgenic expression or in vivo adenoviral delivery at system level.
Light delivery by laser or LED is relatively straightforward in vitro but is challenged in cardiac tissue by motion and light scattering.
Biophysical properties of microbial opsins determine their ability to evoke reliable and precise stimulation or silencing of electrophysiological activity.
Approval Evidence
1 source1 linked approval claimfirst-pass slug spark-cells
Expression of the chosen optogenetic tool in the cardiac cell of interest then requires, at the single-cell level, introduction of opsin-encoding genes by viral transduction, or coupling "spark cells" to primary cardiomyocytes or a stem-cell derived counterpart.
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delivery requirementsupports
Expression of the chosen optogenetic tool in cardiac cells requires gene introduction by viral transduction or coupling via spark cells at the single-cell level, and transgenic expression or in vivo adenoviral delivery at system level.
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Comparisons
Source-stated alternatives
The explicit alternative named in the abstract is viral transduction of opsin-encoding genes.
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The explicit alternative named in the abstract is viral transduction of opsin-encoding genes.
Source-backed strengths
presented as an alternative to viral transduction at the single-cell level
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presented as an alternative to viral transduction at the single-cell level
Compared with mMORp
spark cells and mMORp address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Compared with optogenetic probes
spark cells and optogenetic probes address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Compared with organoid fusion
spark cells and organoid fusion address a similar problem space.
Shared frame: same top-level item type; same primary input modality: light
Ranked Citations
- 1.