Age dependent sensitivity of two-photon isomerization of rhodopsin chromophores in the human retina (Conference Presentation)

2016 ◽  
Author(s):  
Maciej Wojtkowski ◽  
Katarzyna Komar ◽  
Grazyna Palczewska ◽  
Agnieszka Zielinska ◽  
Patrycjusz Stremplewski ◽  
...  
Keyword(s):  
Human Retina ◽  
Two Photon ◽  
Age Dependent

Age-related structural abnormalities in the human retina-choroid complex revealed by two-photon excited autofluorescence imaging

2007 ◽  
Vol 12 (2) ◽  
pp. 024012 ◽  
Author(s):  
Meng Han ◽  
Guenter Giese ◽  
Steffen Schmitz-Valckenberg ◽  
Almut Bindewald-Wittich ◽  
Frank G. Holz ◽  
...  
Keyword(s):  
Human Retina ◽  
Autofluorescence Imaging ◽  
Two Photon ◽  
Age Related ◽  
Structural Abnormalities

scholarly journals Astrocytes dystrophy in ageing brain parallels impaired synaptic plasticity

2020 ◽  
Author(s):  
Alexander Popov ◽  
Alexey Brazhe ◽  
Pavel Denisov ◽  
Oksana Sutyagina ◽  
Natalia Lazareva ◽  
...  
Keyword(s):  
Volume Fraction ◽  
Long Term Potentiation ◽  
Two Photon Microscopy ◽  
Two Photon ◽  
Term Potentiation ◽  
Hippocampal Ca1 ◽  
Age Dependent ◽  
And Function ◽  
The Impact

Little is known about age-dependent changes in structure and function of astrocytes and of the impact of these into the cognitive decline in the senescent brain. The prevalent view on age-dependent increase in reactive astrogliosis and astrocytic hypertrophy requires scrutiny and detailed analysis. Using two-photon microscopy in conjunction with 3D reconstruction, Sholl and volume fraction analysis we demonstrate a significant reduction in the number and the length of astrocytic processes, in astrocytic territorial domains and in astrocyte-to-astrocyte coupling in the aged brain. Probing physiology of astrocytes with patch-clamp and Ca2+ imaging revealed deficits in K+ and glutamate clearance, and spatiotemporal reorganization of Ca2+ events in old astrocytes. These changes paralleled impaired synaptic long-term potentiation (LTP) in hippocampal CA1 in old mice. Our findings may explain astroglial mechanisms of age-dependent decline in learning and memory.

scholarly journals In Vivo Simultaneous Nonlinear Absorption Raman and Fluorescence (SNARF) Imaging of Mouse Brain Cortical Structures

2021 ◽  
Author(s):  
Andrew T Francis ◽  
Bryce Manifold ◽  
Elena C Thomas ◽  
Ruoqian Hu ◽  
Andrew H Hill ◽  
...  
Keyword(s):  
Nonlinear Absorption ◽  
Transient Absorption ◽  
Stimulated Raman Scattering ◽  
Multiphoton Microscopy ◽  
Label Free ◽  
Two Photon ◽  
Age Dependent ◽  
Vessel Structure ◽  
Microscopy Techniques

Two photon excited fluorescence (TPEF) microscopy is a widely used optical imaging technique that has revolutionized neurophotonics through a diverse palette of dyes, specialized transgenic models, easy implementation, and straightforward data analysis. However, in vivo TPEF imaging is often limited in the number of contrasts available to distinguish different cells, structures, or functions. We propose using two label free multiphoton microscopy techniques: stimulated Raman scattering (SRS) microscopy and transient absorption microscopy (TAM) as complementary and orthogonal imaging modalities to TPEF for in vivo brain imaging. In this study, we construct a simultaneous nonlinear absorption, Raman, and fluorescence (SNARF) microscope and image several cortical structures up to 250-300 μm below the pial surface, the highest reported in vivo imaging depth for SRS or TAM. We further demonstrate the capabilities of our SNARF microscope through the quantification of age-dependent myelination, hemodynamics, vessel structure, cell density, and cell identity in vivo. Using machine learning, we report the use of label free SRS and TAM features to predict capillary lining cell identities with 90% accuracy. The SNARF microscope and methodology outlined herein provide a powerful platform to study several research topics, including neurovascular coupling, blood brain barrier, neuronal and axonal degeneration in aging, and neurodegenerative diseases.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Morphological and elemental analysis of isolated incubated frog retina-choroid

1984 ◽  
Vol 42 ◽  
pp. 298-299
Author(s):  
B. J. Panessa-Warren ◽  
J. B. Warren ◽  
H. W. Kraner
Keyword(s):  
Elemental Analysis ◽  
Pigment Epithelium ◽  
Human Retina ◽  
Healthy Individuals ◽  
Anterior Portion ◽  
Pathological Conditions ◽  
Frog Retina ◽  
Isolated Retina ◽  
Vertebrate Eye ◽  
Retina Pigment Epithelium

Our previous studies have demonstrated that abnormally high amounts of calcium (Ca) and zinc (Zn) can be accumulated in human retina-choroid under pathological conditions and that barium (Ba), which was not detected in the eyes of healthy individuals, is deposited in the retina pigment epithelium (RPE), and to a lesser extent in the sensory retina and iris. In an attempt to understand how these cations can be accumulated in the vertebrate eye, a morphological and microanalytical study of the uptake and loss of specific cations (K, Ca,Ba,Zn) was undertaken with incubated Rana catesbiana isolated retina and RPE preparations. Large frogs (650-800 gms) were dark adapted, guillotined and their eyes enucleated in deep ruby light. The eyes were hemisected behind the ora serrata and the anterior portion of the eye removed. The eyecup was bisected along the plane of the optic disc and the two segments of retina peeled away from the RPE and incubated.

Two-photon excitation microscopy in cellular biophysics

1995 ◽  
Vol 53 ◽  
pp. 62-63
Author(s):  
David W. Piston ◽  
Brian D. Bennett ◽  
Robert G. Summers
Keyword(s):  
Confocal Microscopy ◽  
Laser Beam ◽  
Duty Cycle ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation microscopy (TPEM) provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging and photochemistry. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10-5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

Two-photon excitation fluorescence microscopy in living systems

1993 ◽  
Vol 51 ◽  
pp. 154-155 ◽  
Author(s):  
David W. Piston
Keyword(s):  
Confocal Microscopy ◽  
Fluorescence Microscopy ◽  
Singlet State ◽  
Excited Electronic State ◽  
Input Power ◽  
Two Photon ◽  
Simultaneous Absorption ◽  
Photon Excitation ◽  
Very High ◽  
Two Photon Excitation

Two-photon excitation fluorescence microscopy provides attractive advantages over confocal microscopy for three-dimensionally resolved fluorescence imaging. Two-photon excitation arises from the simultaneous absorption of two photons in a single quantitized event whose probability is proportional to the square of the instantaneous intensity. For example, two red photons can cause the transition to an excited electronic state normally reached by absorption in the ultraviolet. In our fluorescence experiments, the final excited state is the same singlet state that is populated during a conventional fluorescence experiment. Thus, the fluorophore exhibits the same emission properties (e.g. wavelength shifts, environmental sensitivity) used in typical biological microscopy studies. In practice, two-photon excitation is made possible by the very high local instantaneous intensity provided by a combination of diffraction-limited focusing of a single laser beam in the microscope and the temporal concentration of 100 femtosecond pulses generated by a mode-locked laser. Resultant peak excitation intensities are 106 times greater than the CW intensities used in confocal microscopy, but the pulse duty cycle of 10−5 maintains the average input power on the order of 10 mW, only slightly greater than the power normally used in confocal microscopy.

1248: Impact of Surgical Treatment of Renal Carcinoma on Renal Function and Blood Pressure: A Race- and Age-Dependent Association

2007 ◽  
Vol 177 (4S) ◽  
pp. 411-412
Author(s):  
Javier Miller ◽  
Angela Smith ◽  
Kris Gunn ◽  
Erik Kouba ◽  
Eric M. Wallen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Renal Function ◽  
Surgical Treatment ◽  
Renal Carcinoma ◽  
Age Dependent
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