scholarly journals Single cell in vivo brain optogenetic stimulation by two-photon excitation fluorescence transfer

Author(s):  
Lei Tong ◽  
Peng Yuan ◽  
Minggang Chen ◽  
Fuyi Chen ◽  
Joerg Bewersdorf ◽  
...  

AbstractOptogenetics at single-cell resolution can be achieved by two-photon stimulation; however, this requires intense or holographic illumination. We markedly improve stimulation efficiency by positioning fluorophores with high two-photon cross-sections adjacent to opsins. The two-photon-excited fluorescence matches the opsin absorbance and can stimulate opsins in a highly localized manner through efficient single-photon absorption. This indirect fluorescence transfer illumination allows experiments difficult to implement in the live brain such as all-optical neural interrogation and control of regional cerebral blood flow.

Author(s):  
John V. Garcia ◽  
Fan Zhang ◽  
Peter C. Ford

Multi-photon excitation allows one to use tissue transmitting near-infrared (NIR) light to access excited states with energies corresponding to single-photon excitation in the visible or ultraviolet wavelength ranges. Here, we present an overview of the application of both simultaneous and sequential multi-photon excitation in studies directed towards the photochemical delivery (‘uncaging’) of bioactive small molecules such as nitric oxide (NO) to physiological targets. Particular focus will be directed towards the use of dyes with high two-photon absorption cross sections and lanthanide ion-doped upconverting nanoparticles as sensitizers to facilitate the uncaging of NO using NIR excitation.


2008 ◽  
Vol 2008 ◽  
pp. 1-11 ◽  
Author(s):  
V. M. Yashchuk ◽  
S. M. Yarmoluk ◽  
V. Yu. Kudrya ◽  
M. Yu. Losytskyy ◽  
V. P. Tokar ◽  
...  

The spectral properties of novel styryl dyes developed for the biomacromolecules (such as DNA) detection and imaging were investigated. The energy structures of dye molecules were examined. The spectral data prove that dyes aggregate and interact with DNA. The essential increase of the fluorescence intensity of dyes in the presence of DNA was observed. The photostability and phototoxic influence on the DNA of several styryl dyes were studied by analyzing absorption, fluorescence, and phosphorescence spectra of these dyes and dye-DNA systems. Changes of the optical density value of dye-DNA solutions caused by the irradiation were fixed in the DNA and dye absorption wavelength regions. Fluorescence emission of dye-DNA complexes upon two-photon excitation at wavelength 1064 nm with the 20-nanosecond pulsed YAG:Nd3+ laser and at 840 nm with the 90 famtosecond pulsed Ti:sapphire laser was registered. The values of two-photon absorption cross-sections of dye-DNA complexes were evaluated.


2021 ◽  
Author(s):  
Philip J. O’Herron ◽  
David A. Hartmann ◽  
Kun Xie ◽  
Prakash Kara ◽  
Andy Y. Shih

AbstractModulation of brain arteriole diameter is critical for maintenance of cerebral blood pressure and control of hyperemia during regional neural activity. However, studies of hemodynamic function in health and disease have lacked a method to control and monitor blood flow with high spatiotemporal resolution. Here, we describe a new all-optical approach to precisely control and monitor arteriolar contractility in vivo using combined two-photon optogenetics and imaging. The expression of the excitatory opsin, ReaChR, in vascular smooth muscle cells enabled rapid and repeated vasoconstriction following brief light pulses. Targeted two-photon activation of ReaCHR using a spatial light modulator (SLM) produced highly localized constrictions when targeted to individual arteries within the neocortex. We demonstrate the utility of this method for examining arteriole contractile dynamics and creating transient blood flow reductions. Additionally, we show that optogenetic constriction can offset or completely block sensory stimulus evoked vasodilation, providing a valuable tool to dissociate blood flow changes from neural activity.


2019 ◽  
Author(s):  
Nicolò Accanto ◽  
I-Wen Chen ◽  
Emiliano Ronzitti ◽  
Clément Molinier ◽  
Christophe Tourain ◽  
...  

AbstractIn the past 10 years, the use of light has become irreplaceable for the optogenetic study and control of neurons and neural circuits. Optical techniques are however limited by scattering and can only see through a depth of few hundreds µm in living tissues. GRIN lens based micro-endoscopes represent a powerful solution to reach deeper regions. In this work we demonstrate that cutting edge optical methods for the precise photostimulation of multiple neurons in three dimensions can be performed through a GRIN lens. By spatio-temporally shaping a laser beam in the two-photon regime we project several tens of targets, spatially confined to the size of a single cell, in a volume of 150×150×400 μm3. We then apply such concept to the optogenetic stimulation of multiple neurons simultaneously in vivo in mice. Our work paves the way for an all-optical investigation of neural circuits at previously unattainable depths.


2005 ◽  
Vol 70 (2) ◽  
pp. 201-208 ◽  
Author(s):  
L.U. Ping ◽  
Ming Xia

Three new thiophene based organic luminescence compounds, i.e., 2,5-bis(4?-N,N-dimethylaminostyryl) thiophene (BMST), 2,5-bis(4?-N,N-diethylaminostyryl)thiophene (BEST) and 2,5-bis(4?-N-cyclobutylaminostyryl)thiophene (BBST), were synthesized. All of their measured single-photon excited fluorescence (SPEF) are located in the range of ? 530 nm with quantum yields of around 40 %, and the corresponding lifetime was ? 1 ns. The examined compounds show strong solvatochromism in their SPEF spectra. Excited by a fs laser at 800 nm, a strong up-converted fluorescence of the examined compounds was detected. The profile of two-proton excited fluorescence (TPEF) was similar to that of SPEF. The two-photon absorption (TPA) cross sections of the compounds were determined by the TPEF method. All the compounds showed large TPA cross sections. Hence these thiophene derivatives may have good TPA properties.


2014 ◽  
Vol 50 (79) ◽  
pp. 11694-11697 ◽  
Author(s):  
N. Arul Murugan ◽  
Robert Zaleśny ◽  
Jacob Kongsted ◽  
Agneta Nordberg ◽  
Hans Ågren

A novel relationship between the charge-transfer descriptor, Δr, and two-photon absorption cross-sections in NIRF probes.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yingzhong Zhu ◽  
Lufei Xiao ◽  
Meng Zhao ◽  
Jiazheng Zhou ◽  
Qiong Zhang ◽  
...  

A new series of D-π-A type imidazole derivatives have been synthesized and characterized. Two corresponding imidazolium salts (iodine and hexafluorophosphate) were prepared from the imidazole compound. Their electron-withdrawing ability can be largely tunable by salt formation reaction or ion exchange. UV-vis absorption and single-photon fluorescence spectra have been systematically investigated in different solvents. The two-photon cross sectionsδ2PAof the imidazole derivatives are measured by two-photon excited fluorescence (2PEF) method. Compared with those ofT-1(107 GM) andT-3(96 GM),T-2(imidazolium iodine salt) has a large two-photon absorption (2PA) cross section value of 276 GM. Furthermore, the cytotoxicity and applications in bioimaging for the imidazole derivatives were carried out. The results showed thatT-1can be used as a lysosomal tracker with high stability and water solubility within pHs of 4–6, whileT-2andT-3can be used as probes for cell cytoplasm.


Sign in / Sign up

Export Citation Format

Share Document