Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

High-throughput synapse-resolving two-photon fluorescence microendoscopy for deep-brain volumetric imaging in vivo.

ABSTRACT: Optical imaging has become a powerful tool for studying brains in vivo. The opacity of adult brains makes microendoscopy, with an optical probe such as a gradient index (GRIN) lens embedded into brain tissue to provide optical relay, the method of choice for imaging neurons and neural activity in deeply buried brain structures. Incorporating a Bessel focus scanning module into two-photon fluorescence microendoscopy, we extended the excitation focus axially and improved its lateral resolution. Scanning the Bessel focus in 2D, we imaged volumes of neurons at high-throughput while resolving fine structures such as synaptic terminals. We applied this approach to the volumetric anatomical imaging of dendritic spines and axonal boutons in the mouse hippocampus, and functional imaging of GABAergic neurons in the mouse lateral hypothalamus in vivo.

SUBMITTER: Meng G

PROVIDER: S-EPMC6338462 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

In vivo mammalian brain imaging using one- and two-photon fluorescence microendoscopy.

Project description:One of the major limitations in the current set of techniques available to neuroscientists is a dearth of methods for imaging individual cells deep within the brains of live animals. To overcome this limitation, we developed two forms of minimally invasive fluorescence microendoscopy and tested their abilities to image cells in vivo. Both one- and two-photon fluorescence microendoscopy are based on compound gradient refractive index (GRIN) lenses that are 350-1,000 microm in diameter and provide micron-scale resolution. One-photon microendoscopy allows full-frame images to be viewed by eye or with a camera, and is well suited to fast frame-rate imaging. Two-photon microendoscopy is a laser-scanning modality that provides optical sectioning deep within tissue. Using in vivo microendoscopy we acquired video-rate movies of thalamic and CA1 hippocampal red blood cell dynamics and still-frame images of CA1 neurons and dendrites in anesthetized rats and mice. Microendoscopy will help meet the growing demand for in vivo cellular imaging created by the rapid emergence of new synthetic and genetically encoded fluorophores that can be used to label specific brain areas or cell classes.

| S-EPMC2826362 | biostudies-literature

High-speed volumetric two-photon fluorescence imaging of neurovascular dynamics.

Project description:Understanding the structure and function of vasculature in the brain requires us to monitor distributed hemodynamics at high spatial and temporal resolution in three-dimensional (3D) volumes in vivo. Currently, a volumetric vasculature imaging method with sub-capillary spatial resolution and blood flow-resolving speed is lacking. Here, using two-photon laser scanning microscopy (TPLSM) with an axially extended Bessel focus, we capture volumetric hemodynamics in the awake mouse brain at a spatiotemporal resolution sufficient for measuring capillary size and blood flow. With Bessel TPLSM, the fluorescence signal of a vessel becomes proportional to its size, which enables convenient intensity-based analysis of vessel dilation and constriction dynamics in large volumes. We observe entrainment of vasodilation and vasoconstriction with pupil diameter and measure 3D blood flow at 99 volumes/second. Demonstrating high-throughput monitoring of hemodynamics in the awake brain, we expect Bessel TPLSM to make broad impacts on neurovasculature research.

| S-EPMC7693336 | biostudies-literature

Time-lapse imaging of disease progression in deep brain areas using fluorescence microendoscopy.

Project description:The combination of intravital microscopy and animal models of disease has propelled studies of disease mechanisms and treatments. However, many disorders afflict tissues inaccessible to light microscopy in live subjects. Here we introduce cellular-level time-lapse imaging deep within the live mammalian brain by one- and two-photon fluorescence microendoscopy over multiple weeks. Bilateral imaging sites allowed longitudinal comparisons within individual subjects, including of normal and diseased tissues. Using this approach, we tracked CA1 hippocampal pyramidal neuron dendrites in adult mice, revealing these dendrites' extreme stability and rare examples of their structural alterations. To illustrate disease studies, we tracked deep lying gliomas by observing tumor growth, visualizing three-dimensional vasculature structure and determining microcirculatory speeds. Average erythrocyte speeds in gliomas declined markedly as the disease advanced, notwithstanding significant increases in capillary diameters. Time-lapse microendoscopy will be applicable to studies of numerous disorders, including neurovascular, neurological, cancerous and trauma-induced conditions.

| S-EPMC3833825 | biostudies-literature

Longitudinal in vivo two-photon fluorescence imaging.

Project description:Fluorescence microscopy is an essential technique for the basic sciences, especially biomedical research. Since the invention of laser scanning confocal microscopy in the 1980s, which enabled imaging both fixed and living biological tissue with 3D precision, high-resolution fluorescence imaging has revolutionized biological research. Confocal microscopy, by its very nature, has one fundamental limitation. Due to the confocal pinhole, deep tissue fluorescence imaging is not practical. In contrast (no pun intended), two-photon fluorescence microscopy allows, in principle, the collection of all emitted photons from fluorophores in the imaged voxel, dramatically extending our ability to see deep into living tissue. Since the development of transgenic mice with genetically encoded fluorescent protein in neocortical cells in 2000, two-photon imaging has enabled the dynamics of individual synapses to be followed for up to 2 years. Since the initial landmark contributions to this field in 2002, the technique has been used to understand how neuronal structure are changed by experience, learning, and memory and various diseases. Here we provide a basic summary of the crucial elements that are required for such studies, and discuss many applications of longitudinal two-photon fluorescence microscopy that have appeared since 2002.

| S-EPMC4136386 | biostudies-literature

Minimally invasive microendoscopy system for in vivo functional imaging of deep nuclei in the mouse brain.

Project description:The ability to image neurons anywhere in the mammalian brain is a major goal of optical microscopy. Here we describe a minimally invasive microendoscopy system for studying the morphology and function of neurons at depth. Utilizing a guide cannula with an ultrathin wall, we demonstrated in vivo two-photon fluorescence imaging of deeply buried nuclei such as the striatum (2.5 mm depth), substantia nigra (4.4 mm depth) and lateral hypothalamus (5.0 mm depth) in mouse brain. We reported, for the first time, the observation of neuronal activity with subcellular resolution in the lateral hypothalamus and substantia nigra of head-fixed awake mice.

| S-EPMC4646561 | biostudies-literature

Kilohertz two-photon fluorescence microscopy imaging of neural activity in vivo.

Project description:Understanding information processing in the brain requires monitoring neuronal activity at high spatiotemporal resolution. Using an ultrafast two-photon fluorescence microscope empowered by all-optical laser scanning, we imaged neuronal activity in vivo at up to 3,000 frames per second and submicrometer spatial resolution. This imaging method enabled monitoring of both supra- and subthreshold electrical activity down to 345??m below the brain surface in head-fixed awake mice.

| S-EPMC7199528 | biostudies-literature

Multicolor three-photon fluorescence imaging with single-wavelength excitation deep in mouse brain.

Project description:Multiphoton fluorescence microscopy is a powerful technique for deep-tissue observation of living cells. In particular, three-photon microscopy is highly beneficial for deep-tissue imaging because of the long excitation wavelength and the high nonlinear confinement in living tissues. Because of the large spectral separation of fluorophores of different color, multicolor three-photon imaging typically requires multiple excitation wavelengths. Here, we report a new three-photon excitation scheme: excitation to a higher-energy electronic excited state instead of the conventional excitation to the lowest-energy excited state, enabling multicolor three-photon fluorescence imaging with deep-tissue penetration in the living mouse brain using single-wavelength excitation. We further demonstrate that our excitation method results in ≥10-fold signal enhancement for some of the common red fluorescent molecules. The multicolor imaging capability and the possibility of enhanced three-photon excitation cross section will open new opportunities for life science applications of three-photon microscopy.

| S-EPMC7968831 | biostudies-literature

In vivo imaging of the actin polymerization state with two-photon fluorescence anisotropy.

Project description:Using two-photon fluorescence anisotropy imaging of actin-GFP, we have developed a method for imaging the actin polymerization state that is applicable to a broad range of experimental systems extending from fixed cells to live animals. The incorporation of expressed actin-GFP monomers into endogenous actin polymers enables energy migration FRET (emFRET, or homoFRET) between neighboring actin-GFPs. This energy migration reduces the normally high polarization of the GFP fluorescence. We derive a simple relationship between the actin-GFP fluorescence polarization anisotropy and the actin polymer fraction, thereby enabling a robust means of imaging the actin polymerization state with high spatiotemporal resolution and providing what to the best of our knowledge are the first direct images of the actin polymerization state in live, adult brain tissue and live, intact Drosophila larvae.

| S-EPMC3296026 | biostudies-literature

In vivo high-resolution fluorescence microendoscopy for ovarian cancer detection and treatment monitoring.

Project description:BackgroundIn patients with advanced ovarian cancer (OvCa), microscopic residual tumour nodules that remain after surgical debulking frequently escape detection by current treatment assessment methods and lead to disease recurrence. The aim of this study was to evaluate the use of high-resolution fibre-optic fluorescence imaging of the clinically approved photodynamic therapy (PDT) agent benzoporphyin-derivative monoacid ring A (BPD-MA) for detection of microscopic OvCa and for monitoring treatment response.MethodsOur fluorescence microendoscope consists of a flexible imaging fibre coupled to a custom epi-fluorescence system optimised for imaging BPD-MA, which, after a single administration, serves as both an imaging agent and a light-activated therapeutic agent. After characterisation in an in vitro OvCa 3D model, we used the flexible imaging fibre to minimally invasively image the peritoneal cavity of a disseminated OvCa murine model using BPD-MA administered intraperitoneally (i.p.). To evaluate longitudinal changes in response to treatment, we compared sets of images obtained before and after PDT with those from untreated mice imaged at the same time points.ResultsBy comparison with histopathology, we report an 86% sensitivity for tumour detection in vivo using the microendoscope. Using a custom routine to batch process-image data in the monitoring study, treated mice exhibited an average decrease of 58.8% in tumour volumes compared with an increase of 59.3% in untreated controls (P<0.05).ConclusionsOur findings indicate the potential of this approach as a reporter of treatment outcome that could aid in the rational design of strategies to mitigate recurrent OvCa.

| S-EPMC2795438 | biostudies-literature

In vivo volumetric imaging of biological dynamics in deep tissue via wavefront engineering.

Project description:Biological systems undergo dynamical changes continuously which span multiple spatial and temporal scales. To study these complex biological dynamics in vivo, high-speed volumetric imaging that can work at large imaging depth is highly desired. However, deep tissue imaging suffers from wavefront distortion, resulting in reduced Strehl ratio and image quality. Here we combine the two wavefront engineering methods developed in our lab, namely the optical phase-locked ultrasound lens based volumetric imaging and the iterative multiphoton adaptive compensation technique, and demonstrate in vivo volumetric imaging of microglial and mitochondrial dynamics at large depth in mouse brain cortex and lymph node, respectively.

| S-EPMC4741314 | 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