Signal-Based Adaptive Optics Optimization for in-vivo Two-Photon Microscopy of 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

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Adaptive optics two-photon microscopy enables near-diffraction-limited and functional retinal imaging in vivo

Light Science & Applications ◽

10.1038/s41377-020-0317-9 ◽

2020 ◽

Vol 9 (1) ◽

Cited By ~ 5

Author(s):

Zhongya Qin ◽

Sicong He ◽

Chao Yang ◽

Jasmine Sum-Yee Yung ◽

Congping Chen ◽

...

Keyword(s):

Adaptive Optics ◽

Retinal Imaging ◽

Two Photon Microscopy ◽

Two Photon

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

Nature Communications ◽

10.1038/s41467-021-24323-1 ◽

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.

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Adaptive optics two-photon microscopy for in vivo imaging of mouse retina

Adaptive Optics and Wavefront Control for Biological Systems VI ◽

10.1117/12.2546972 ◽

2020 ◽

Author(s):

Zhongya Qin ◽

Sicong He ◽

Congping Chen ◽

Chao Yang ◽

Jasmine Yung ◽

...

Keyword(s):

Adaptive Optics ◽

In Vivo Imaging ◽

Mouse Retina ◽

Two Photon Microscopy ◽

Two Photon

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

10.21203/rs.3.rs-484024/v1 ◽

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.

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High-resolution two-photon transcranial imaging of brain using direct wavefront sensing

10.1101/2020.09.12.294421 ◽

2020 ◽

Author(s):

Congping Chen ◽

Zhongya Qin ◽

Sicong He ◽

Shaojun Liu ◽

Shun-Fat Lau ◽

...

Keyword(s):

High Resolution ◽

Adaptive Optics ◽

Pyramidal Neurons ◽

Imaging System ◽

Superficial Layer ◽

Wavefront Sensing ◽

Two Photon Microscopy ◽

Two Photon ◽

Transcranial Imaging

AbstractImaging of the brain in its native state at high resolution poses major challenges to visualization techniques. Two-photon microscopy integrated with the thinned-skull or optical clearing skull technique provides a minimally invasive tool for in vivo imaging of the cortex of mice without activating immune response and inducing brain injury. However, the imaging contrast and resolution are severely compromised by the optical heterogeneity of the skull, limiting the imaging depth to the superficial layer. Here, we develop adaptive optics two-photon microscopy for high-resolution transcranial imaging of layer 5 pyramidal neurons up to 700 μm below pia in living mice. In particular, an optimized configuration of imaging system and new wavefront sensing algorithm are proposed for accurate correction for the aberrations induced by the skull window and brain tissue. We investigated microglia-plaque interaction in living brain of Alzheimer’s disease and demonstrated high-precision laser dendrotomy and single-spine ablation.

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

10.1101/339531 ◽

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.

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