Two-Photon Photostimulation for Single-Cell Synaptic Mapping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for photostimulation of neuronal circuits, such as one-photon photostimulation, fail to accurately map synaptic connections between neurons due to light scattering in living tissue, resulting in stimulation of multiple neurons instead of specific connections.
Innovation Solution
The use of two-photon photostimulation systems and devices, including diffractive optical arrangements and spatial light modulation (SLM) to precisely target and activate specific neurons, enabling single-cell resolution mapping of synaptic inputs through techniques like beam multiplexing and two-photon calcium imaging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If one-photon photostimulation is used, then the stimulation area covers a large territory, but the spatial precision is poor and multiple neurons are stimulated instead of specific connections
Solution Approach 1:
The patent changes the fundamental parameter of light excitation from one-photon to two-photon absorption. This parameter change enables simultaneous achievement of large stimulation area and high spatial precision, as two-photon excitation occurs only at the focal point where photon density is sufficient, providing intrinsic optical sectioning and single-cell resolution while covering extensive territories
Solution Approach 2:
The patent introduces temporal dimension by using pulsed laser excitation at ultrashort durations (e.g., 100 fs to 10 ps). This temporal dimensionality change allows concentration of energy in time to achieve two-photon absorption only at the focal point, thereby achieving high spatial precision without compromising stimulation area
2Productivity
If ultraviolet light is used for one-photon photostimulation, then the uncaging efficiency is high, but light scattering in living tissue reduces penetration depth and precision
Solution Approach 1:
The patent changes the wavelength parameter from ultraviolet (one-photon) to visible or near-infrared (two-photon). This parameter change reduces light scattering in living tissue while maintaining uncaging efficiency, as two-photon absorption of visible/near-IR light achieves the same chemical effect with reduced scattering and improved tissue penetration
Solution Approach 2:
The patent converts the harmful effect of light scattering into a beneficial filtering mechanism. By using two-photon excitation, only photons that converge at the focal point (where intensity is highest) can induce uncaging, effectively using the scattering environment to enhance spatial selectivity while maintaining efficiency
3Area of stationary object
If one-photon photostimulation with large uncaging area is used, then the coverage is extensive, but synaptic connections between specific cells cannot be resolved
Solution Approach 1:
The patent changes the excitation parameter to two-photon absorption with pulsed lasers, which provides intrinsic optical sectioning. This allows extensive area coverage while maintaining single-cell resolution, thereby preserving synaptic connection information that would otherwise be lost in one-photon methods
4Quantity of substance
If systematic beam scanning is used to map territories, then the coverage is comprehensive, but the time required for mapping is excessive
Solution Approach 1:
The patent segments the stimulation process by using beam multiplexing to simultaneously stimulate multiple discrete locations. This segmentation allows comprehensive mapping coverage to be achieved in parallel, dramatically reducing the time required compared to sequential scanning while maintaining complete territorial coverage
Solution Approach 2:
The patent employs periodic pulsed laser excitation at high repetition rates. This periodic action enables rapid sequential or simultaneous stimulation of multiple locations, reducing total mapping time while maintaining comprehensive coverage through the high temporal resolution of pulsed excitation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach allows for the generation of high-resolution input maps with single-cell precision, overcoming the limitations of one-photon methods by accurately identifying monosynaptic connections and providing detailed synaptic properties, while minimizing photodamage and improving signal-to-noise ratio.
Implementation Method 1
two-photon photostimulation systems and devices, including diffractive optical arrangements and spatial light modulation (SLM) to precisely target and activate specific neurons
Implementation Method 2
diffractive optical arrangements and spatial light modulation (SLM) to precisely target and activate specific neurons, enabling single-cell resolution mapping
Implementation Method 3
spatial light modulation (SLM) to precisely target and activate specific neurons, enabling single-cell resolution mapping of synaptic inputs
Implementation Method 4
two-photon calcium imaging
Data Source
AI summary
According to exemplary embodiments of the present disclosure, it is possible to provide method, system, arrangement, computer-accessible medium and device to stimulate individual neurons in brain slices in any arbitrary spatio-temporal pattern, using two-photon uncaging of photo-sensitive compounds such as MNI-glutamate and/or RuBi-Glutamate with beam multiplexing. Such exemplary method and device can have single-cell and three-dimensional precision. For example, by sequentially stimulating up to a thousand potential presynaptic neurons, it is possible to generate detailed functional maps of inputs to a cell. In addition, it is possible to combine this exemplary approach with two-photon calcium imaging in an all-optical method to image and manipulate circuit activity. Further exemplary embodiments of the present disclosure can include a light-weight, compact portable device providing for uses in a wide variety of applications.