Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Exploring two-photon optogenetics beyond 1100 nm for specific and effective all-optical physiology.

ABSTRACT: Two-photon (2-P) all-optical approaches combine in vivo 2-P calcium imaging and 2-P optogenetic modulations. Here, firstly, we combined in vivo juxtacellular recordings and GCaMP6f-based 2-P calcium imaging in mouse visual cortex to tune our detection algorithm towards a 100% specific identification of action potential-related calcium transients. Secondly, we minimized photostimulation artifacts by using extended-wavelength-spectrum laser sources for optogenetic stimulation. We achieved artifact-free all-optical experiments performing optogenetic stimulation from 1100 nm to 1300 nm. Thirdly, we determined the spectral range for maximizing efficacy until 1300 nm. The rate of evoked transients in GCaMP6f/C1V1-co-expressing cortical neurons peaked already at 1100 nm. By refining spike detection and defining 1100 nm as the optimal wavelength for artifact-free and effective GCaMP6f/C1V1-based all-optical physiology, we increased the translational value of these approaches, e.g., for the development of network-based therapies.

SUBMITTER: Fu T

PROVIDER: S-EPMC7921810 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Refractive index of human red blood cells between 290 nm and 1100 nm determined by optical extinction measurements.

Project description:The knowledge of optical properties of biological cells is essential to interpret their interaction with light and to derive morphological information and parameters associated with cell function like the oxygen transport capacity of human red blood cells (RBCs). We present a method to determine the dependence between the refractive index (RI) of human RBCs and their intracellular hemoglobin (Hb) concentration from spectral extinction measurements of a cell suspension. The procedure is based on the analysis of the corresponding ensemble averaged extinction cross section [Formula: see text]. Thus far two complementary approaches have been taken to derive RIs of RBCs. The first one uses homogeneous macroscopic samples prepared by hemolysis for the destruction of the RBCs' membranes and subsequent centrifugation. A second approach is the determination of RIs of single intact cells by microscopic investigation. These techniques are limited to a few discrete wavelengths or a rather narrow wavelength range. In addition most of these techniques require additional information about the concentration dependence. In contrast, our approach yields the RI increment with Hb concentration of intact, reversibly isovolumetrically sphered, oxygenated RBCs over a wide wavelength range from 290 nm to 1100 nm from macroscopic measurements.

| S-EPMC6420646 | biostudies-literature

Hollow core optical fibres with comparable attenuation to silica fibres between 600 and 1100 nm.

Project description:For over 50 years, pure or doped silica glass optical fibres have been an unrivalled platform for the transmission of laser light and optical data at wavelengths from the visible to the near infra-red. Rayleigh scattering, arising from frozen-in density fluctuations in the glass, fundamentally limits the minimum attenuation of these fibres and hence restricts their application, especially at shorter wavelengths. Guiding light in hollow (air) core fibres offers a potential way to overcome this insurmountable attenuation limit set by the glass's scattering, but requires reduction of all the other loss-inducing mechanisms. Here we report hollow core fibres, of nested antiresonant design, with losses comparable or lower than achievable in solid glass fibres around technologically relevant wavelengths of 660, 850, and 1060 nm. Their lower than Rayleigh scattering loss in an air-guiding structure offers the potential for advances in quantum communications, data transmission, and laser power delivery.

| S-EPMC7695690 | biostudies-literature

Simultaneous two-photon imaging and two-photon optogenetics of cortical circuits in three dimensions.

Project description:The simultaneous imaging and manipulating of neural activity could enable the functional dissection of neural circuits. Here we have combined two-photon optogenetics with simultaneous volumetric two-photon calcium imaging to measure and manipulate neural activity in mouse neocortex in vivo in three-dimensions (3D) with cellular resolution. Using a hybrid holographic approach, we simultaneously photostimulate more than 80 neurons over 150 ?m in depth in layer 2/3 of the mouse visual cortex, while simultaneously imaging the activity of the surrounding neurons. We validate the usefulness of the method by photoactivating in 3D selected groups of interneurons, suppressing the response of nearby pyramidal neurons to visual stimuli in awake animals. Our all-optical approach could be used as a general platform to read and write neuronal activity.

| S-EPMC5832414 | biostudies-literature

Two-photon optogenetics of dendritic spines and neural circuits.

Project description:We demonstrate a two-photon optogenetic method that generates action potentials in neurons with single-cell precision, using the red-shifted opsin C1V1(T). We applied the method to optically map synaptic circuits in mouse neocortical brain slices and to activate small dendritic regions and individual spines. Using a spatial light modulator, we split the laser beam onto several neurons and performed simultaneous optogenetic activation of selected neurons in three dimensions.

| S-EPMC3518588 | biostudies-literature

Two-photon brightness of azobenzene photoswitches designed for glutamate receptor optogenetics.

Project description:Mammalian neurotransmitter-gated receptors can be conjugated to photoswitchable tethered ligands (PTLs) to enable photoactivation, or photoantagonism, while preserving normal function at neuronal synapses. "MAG" PTLs for ionotropic and metabotropic glutamate receptors (GluRs) are based on an azobenzene photoswitch that is optimally switched into the liganding state by blue or near-UV light, wavelengths that penetrate poorly into the brain. To facilitate deep-tissue photoactivation with near-infrared light, we measured the efficacy of two-photon (2P) excitation for two MAG molecules using nonlinear spectroscopy. Based on quantitative characterization, we find a recently designed second generation PTL, L-MAG0460, to have a favorable 2P absorbance peak at 850 nm, enabling efficient 2P activation of the GluK2 kainate receptor, LiGluR. We also achieve 2P photoactivation of a metabotropic receptor, LimGluR3, with a new mGluR-specific PTL, D-MAG0460. 2P photoswitching is efficiently achieved using digital holography to shape illumination over single somata of cultured neurons. Simultaneous Ca(2+)-imaging reports on 2P photoswitching in multiple cells with high temporal resolution. The combination of electrophysiology or Ca(2+) imaging with 2P activation by optical wavefront shaping should make second generation PTL-controlled receptors suitable for studies of intact neural circuits.

| S-EPMC4343171 | biostudies-literature

Optical characterization of porcine tissues from various organs in the 650-1100 nm range using time-domain diffuse spectroscopy.

Project description:We present a systematic characterization of the optical properties (µa and µs') of nine representative ex vivo porcine tissues over a broadband spectrum (650-1100 nm). We applied time-resolved diffuse optical spectroscopy measurements for recovering the optical properties of porcine tissues depicting a realistic representation of the tissue heterogeneity and morphology likely to be found in different ex vivo tissues. The results demonstrate a large spectral and inter-tissue variation of optical properties. The data can be exploited for planning or simulating ex vivo experiments with various biophotonics techniques, or even to construct artificial structures mimicking specific pathologies exploiting the wide assortment in optical properties.

| S-EPMC7075607 | biostudies-literature

Optically selective two-photon uncaging of glutamate at 900 nm.

Project description:We have synthesized a 7-diethylaminocoumarin (DEAC) derivative that allows wavelength-selective two-photon uncaging at 900 nm versus 720 nm. This new caging chromophore, called DEAC450, has an extended ?-electron moiety at the 3-position that shifts the absorption spectrum maximum of DEAC from 375 to 450 nm. Two-photon excitation at 900 nm was more than 60-fold greater than at 720 nm. Two-photon uncaging of DEAC450-Glu at 900 nm at spine heads on pyramidal neurons in acutely isolated brain slices generated postsynaptic responses that were similar to spontaneous postsynaptic excitatory miniature currents, whereas significantly higher energies at 720 nm evoked no currents. Since many nitroaromatic caged compounds are two-photon active at 720 nm, optically selective uncaging of DEAC450-caged biomolecules at 900 nm may allow facile two-color optical interrogation of bimodal signaling pathways in living tissue with high resolution for the first time.

| S-EPMC4079120 | biostudies-literature

Noninvasive two-photon optical biopsy of retinal fluorophores.

Project description:High-resolution imaging techniques capable of detecting identifiable endogenous fluorophores in the eye along with genetic testing will dramatically improve diagnostic capabilities in the ophthalmology clinic and accelerate the development of new treatments for blinding diseases. Two-photon excitation (TPE)-based imaging overcomes the filtering of ultraviolet light by the lens of the human eye and thus can be utilized to discover defects in vitamin A metabolism during the regeneration of the visual pigments required for the detection of light. Combining TPE with fluorescence lifetime imaging (FLIM) and spectral analyses offers the potential of detecting diseases of the retina at earlier stages before irreversible structural damage has occurred. The main barriers to realizing the benefits of TPE for imaging the human retina arise from concerns about the high light exposure typically needed for informative TPE imaging and the requirement to correlate the ensuing data with different states of health and disease. To overcome these hurdles, we improved TPE efficiency by controlling temporal properties of the excitation light and employed phasor analyses to FLIM and spectral data in mouse models of retinal diseases. Modeling of retinal photodamage revealed that plasma-mediated effects do not play a role and that melanin-related thermal effects are mitigated by reducing pulse repetition frequency. By using noninvasive TPE imaging we identified molecular components of individual granules in the retinal pigment epithelium and present their analytical characteristics.

| S-EPMC7486747 | biostudies-literature

Two-photon uncaging of bioactive thiols in live cells at wavelengths above 800 nm.

Project description:Photoactivatable protecting groups (PPGs) are useful for a broad range of applications ranging from biology to materials science. In chemical biology, induction of biological processes via photoactivation is a powerful strategy for achieving spatiotemporal control. The importance of cysteine, glutathione, and other bioactive thiols in regulating protein structure/activity and cell redox homeostasis makes modulation of thiol activity particularly useful. One major objective for enhancing the utility of photoactivatable protecting groups (PPGs) in living systems is creating PPGs with longer wavelength absorption maxima and efficient two-photon (TP) absorption. Toward these objectives, we developed a carboxyl- and dimethylamine-functionalized nitrodibenzofuran PPG scaffold (cDMA-NDBF) for thiol photoactivation, which has a bathochromic shift in the one-photon absorption maximum from λmax = 315 nm with the unfunctionalized NDBF scaffold to λmax = 445 nm. While cDMA-NDBF-protected thiols are stable in the presence of UV irradiation, they undergo efficient broad-spectrum TP photolysis at wavelengths as long as 900 nm. To demonstrate the wavelength orthogonality of cDMA-NDBF and NDBF photolysis in a biological setting, caged farnesyltransferase enzyme inhibitors (FTI) were prepared and selectively photoactivated in live cells using 850-900 nm TP light for cDMA-NDBF-FTI and 300 nm UV light for NDBF-FTI. These experiments represent the first demonstration of thiol photoactivation at wavelengths above 800 nm. Consequently, cDMA-NDBF-caged thiols should have broad applicability in a wide range of experiments in chemical biology and materials science.

| S-EPMC8437107 | biostudies-literature

Two-photon optical interrogation of individual dendritic spines with caged dopamine.

Project description:We introduce a novel caged dopamine compound (RuBi-Dopa) based on ruthenium photochemistry. RuBi-Dopa has a high uncaging efficiency and can be released with visible (blue-green) and IR light in a two-photon regime. We combine two-photon photorelease of RuBi-Dopa with two-photon calcium imaging for an optical imaging and manipulation of dendritic spines in living brain slices, demonstrating that spines can express functional dopamine receptors. This novel compound allows mapping of functional dopamine receptors in living brain tissue with exquisite spatial resolution.

| S-EPMC3750683 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data