scholarly journals Whole-brain imaging and characterization of Drosophila brains based on one-, two-, and three-photon excitations

2018 ◽  
Author(s):  
Kuo-Jen Hsu ◽  
Yen-Yin Lin ◽  
Ann-Shyn Chiang ◽  
Shi-Wei Chu
Keyword(s):  
High Speed ◽  
Optical Sectioning ◽  
Whole Brain ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Functional Connectome ◽  
Molecular Specificity ◽  
The Brain

AbstractTo study functional connectome, optical microscopy provides the advantages of in vivo observation, molecular specificity, high-speed acquisition, and sub-micrometer spatial resolution. Now, the most complete single-neuron-based anatomical connectome is built upon Drosophila; thus it will be a milestone to achieve whole-brain observation with sub-cellular resolution in living Drosophila. Surprisingly, two-photon microscopy cannot penetrate through the 200-μm-thick brain, due to the extraordinarily strong aberration/scattering from tracheae. Here we achieve whole-Drosophila-brain observation by degassing the brain or by using three-photon microscopy at 1300-nm, while only the latter provides in vivo feasibility, reduced aberration/scattering and exceptional optical sectioning capability. Furthermore, by comparing one-photon (488-nm), two-photon (920-nm), and three-photon (1300-nm) excitations in the brain, we not only demonstrate first quantitative reduction of both scattering and aberration in trachea-filled tissues, but unravel that the contribution of aberration exceeds scattering at long wavelengths. Our work paves the way toward constructing functional connectome in a living Drosophila.

scholarly journals P02.08 Visualizing tumor cell - lymphocyte interactions in the brain metastatic cascade using in vivo two photon microscopy

2018 ◽  
Vol 20 (suppl_3) ◽  
pp. iii273-iii273
Author(s):  
M Piechutta ◽  
A S Berghoff ◽  
M A Karreman ◽  
K Gunkel ◽  
W Wick ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Metastatic Cascade ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
The Brain

scholarly journals IMMU-26. VISUALIZING TUMOR CELL - LYMPHOCYTE INTERACTIONS IN THE BRAIN METASTATIC CASCADE USING IN VIVO TWO PHOTON MICROSCOPY

2018 ◽  
Vol 20 (suppl_6) ◽  
pp. vi126-vi127
Author(s):  
Manuel Piechutta ◽  
Anna Berghoff ◽  
Matthia Karreman ◽  
Katharina Gunkel ◽  
Wolfgang Wick ◽  
...  
Keyword(s):  
Tumor Cell ◽  
Metastatic Cascade ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
The Brain

scholarly journals Post-capillary venules is the locus for transcytosis of therapeutic nanoparticles to the brain

2020 ◽  
Author(s):  
Krzysztof Kucharz ◽  
Kasper Kristensen ◽  
Kasper Bendix Johnsen ◽  
Mette Aagaard Lund ◽  
Micael Lønstrup ◽  
...  
Keyword(s):  
Drug Carrier ◽  
Basement Membranes ◽  
List Type ◽  
Biologic Drugs ◽  
Large Molecules ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Resolution Imaging ◽  
The Brain

SUMMARYTreatments of neurodegenerative diseases require biologic drugs to be actively transported across the blood-brain barrier (BBB). To answer outstanding questions regarding transport mechanisms, we determined how and where transcytosis occurs at the BBB. Using two-photon microscopy, we characterized the transport of therapeutic nanoparticles at all steps of delivery to the brain and at the nanoscale resolution in vivo. Transferrin receptor-targeted nanoparticles were taken up by endothelium at capillaries and venules, but not at arterioles. The nanoparticles moved unobstructed within endothelial cells, but transcytosis across the BBB occurred only at post-capillary venules, where endothelial and glial basement membranes form a perivascular space that can accommodate biologics. In comparison, transcytosis was absent in capillaries with closely apposed basement membranes. Thus, post-capillary venules, not capillaries, provide an entry point for transport of large molecules across the BBB, and targeting therapeutic agents to this locus may be an effective way for treating brain disorders.HIGHLIGHTSIntegration of drug carrier nanotechnology with two-photon microscopy in vivoReal-time nanoscale-resolution imaging of nanoparticle transcytosis to the brainDistinct trafficking pattern in the endothelium of cerebral venules and capillariesVenules, not capillaries, is the locus for brain uptake of therapeutic nanoparticles

scholarly journals Photon counting, censor corrections, and lifetime imaging for improved detection in two-photon microscopy

2011 ◽  
Vol 105 (6) ◽  
pp. 3106-3113 ◽  
Author(s):  
Jonathan D. Driscoll ◽  
Andy Y. Shih ◽  
Satish Iyengar ◽  
Jeffrey J. Field ◽  
G. Allen White ◽  
...  
Keyword(s):  
High Speed ◽  
Signal To Noise Ratio ◽  
Photon Counting ◽  
In Vivo Model ◽  
Fluorescence Lifetime Imaging ◽  
Photon Counter ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Lifetime Imaging

We present a high-speed photon counter for use with two-photon microscopy. Counting pulses of photocurrent, as opposed to analog integration, maximizes the signal-to-noise ratio so long as the uncertainty in the count does not exceed the gain-noise of the photodetector. Our system extends this improvement through an estimate of the count that corrects for the censored period after detection of an emission event. The same system can be rapidly reconfigured in software for fluorescence lifetime imaging, which we illustrate by distinguishing between two spectrally similar fluorophores in an in vivo model of microstroke.

scholarly journals Post-capillary venules are the key locus for transcytosis-mediated brain delivery of therapeutic nanoparticles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Krzysztof Kucharz ◽  
Kasper Kristensen ◽  
Kasper Bendix Johnsen ◽  
Mette Aagaard Lund ◽  
Micael Lønstrup ◽  
...  
Keyword(s):  
Transferrin Receptor ◽  
Drug Carriers ◽  
Perivascular Space ◽  
Brain Uptake ◽  
Brain Delivery ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Basic Understanding ◽  
The Brain

AbstractEffective treatments of neurodegenerative diseases require drugs to be actively transported across the blood-brain barrier (BBB). However, nanoparticle drug carriers explored for this purpose show negligible brain uptake, and the lack of basic understanding of nanoparticle-BBB interactions underlies many translational failures. Here, using two-photon microscopy in mice, we characterize the receptor-mediated transcytosis of nanoparticles at all steps of delivery to the brain in vivo. We show that transferrin receptor-targeted liposome nanoparticles are sequestered by the endothelium at capillaries and venules, but not at arterioles. The nanoparticles move unobstructed within endothelium, but transcytosis-mediated brain entry occurs mainly at post-capillary venules, and is negligible in capillaries. The vascular location of nanoparticle brain entry corresponds to the presence of perivascular space, which facilitates nanoparticle movement after transcytosis. Thus, post-capillary venules are the point-of-least resistance at the BBB, and compared to capillaries, provide a more feasible route for nanoparticle drug carriers into the brain.

scholarly journals Ca2+ Imaging With Two-photon Microscopy to Detect the Disruption of Brain Function in Mice Administered With Neonicotinoid Insecticides

2021 ◽  
Author(s):  
Anri Hirai ◽  
Shouta Sugio ◽  
Collins Nimako ◽  
Shouta Nakayama ◽  
Keisuke Kato ◽  
...  
Keyword(s):  
Lethal Dose ◽  
Neuronal Population ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Adverse Effect Level ◽  
Effect Level ◽  
Highly Sensitive Detection ◽  
Neonicotinoid Pesticides ◽  
The Brain

Abstract Neonicotinoid pesticides are insecticides that are insecticides that reportedly have untargeted effects on bees and dragonflies causing a reduction in numbers. Neonicotinoids act as neuroreceptor modulators, and some studies have reported their association with neurodevelopmental disorders. However, the effect of neonicotinoids on the central nervous system has not yet been identified. Herein, we conducted in vivo Ca2+ imaging using a two-photon microscope to detect abnormal activity of neuronal circuits in the brain using a neonicotinoid. The oral administration of acetamiprid (ACE) (20 mg/kg body weight [bw]) in mature mice with a less than the no-observed-adverse-effect level (NOAEL) and a tenth or half of the median lethal dose (LD50) of nicotine (0.33 or 1.65 mg/kg bw, respectively), as a typical nAChRs agonist, increased anxiety-like behavior associated with altered activities of the neuronal population in the somatosensory cortex. Furthermore, we detected ACE and metabolites in the brain 1 h after ACE administration. The results suggested that in vivo Ca2+ imaging using a two-photon microscope enabled the highly sensitive detection of neurotoxicant-mediated brain disturbance of nerves.

scholarly journals In vivo characterization of early-stage radiation skin injury in a mouse model by two-photon microscopy

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Won Hyuk Jang ◽  
Sehwan Shim ◽  
Taejun Wang ◽  
Yeoreum Yoon ◽  
Won-Suk Jang ◽  
...  
Keyword(s):  
Mouse Model ◽  
Early Stage ◽  
Skin Injury ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
In Vivo Characterization

In vivo imaging of liver injury and regeneration by functional two-photon microscopy

2016 ◽  
Vol 54 (12) ◽  
pp. 1343-1404
Author(s):  
A Ghallab ◽  
R Reif ◽  
R Hassan ◽  
AS Seddek ◽  
JG Hengstler
Keyword(s):  
Liver Injury ◽  
In Vivo Imaging ◽  
Two Photon Microscopy ◽  
Two Photon

Implantable neural interfaces

2018 ◽  
Author(s):  
Stefano Vassanelli
Keyword(s):  
Brain Function ◽  
Large Scale ◽  
Ionic Channels ◽  
Patch Clamp Technique ◽  
Advantages And Disadvantages ◽  
Optogenetic Stimulation ◽  
Physical Interfaces ◽  
The Brain

Establishing direct communication with the brain through physical interfaces is a fundamental strategy to investigate brain function. Starting with the patch-clamp technique in the seventies, neuroscience has moved from detailed characterization of ionic channels to the analysis of single neurons and, more recently, microcircuits in brain neuronal networks. Development of new biohybrid probes with electrodes for recording and stimulating neurons in the living animal is a natural consequence of this trend. The recent introduction of optogenetic stimulation and advanced high-resolution large-scale electrical recording approaches demonstrates this need. Brain implants for real-time neurophysiology are also opening new avenues for neuroprosthetics to restore brain function after injury or in neurological disorders. This chapter provides an overview on existing and emergent neurophysiology technologies with particular focus on those intended to interface neuronal microcircuits in vivo. Chemical, electrical, and optogenetic-based interfaces are presented, with an analysis of advantages and disadvantages of the different technical approaches.

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