Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros

Base de dados
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Nat Methods ; 20(4): 617-622, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36823329

RESUMO

In deep-tissue multiphoton microscopy, diffusion and scattering of fluorescent photons, rather than ballistic emanation from the focal point, have been a confounding factor. Here we report on a 2.17-g miniature three-photon microscope (m3PM) with a configuration that maximizes fluorescence collection when imaging in highly scattering regimes. We demonstrate its capability by imaging calcium activity throughout the entire cortex and dorsal hippocampal CA1, up to 1.2 mm depth, at a safe laser power. It also enables the detection of sensorimotor behavior-correlated activities of layer 6 neurons in the posterior parietal cortex in freely moving mice during single-pellet reaching tasks. Thus, m3PM-empowered imaging allows the study of neural mechanisms in deep cortex and subcortical structures, like the dorsal hippocampus and dorsal striatum, in freely behaving animals.


Assuntos
Hipocampo , Microscopia de Fluorescência por Excitação Multifotônica , Camundongos , Animais , Microscopia de Fluorescência por Excitação Multifotônica/métodos , Córtex Cerebral , Corantes , Fótons
2.
Opt Express ; 31(20): 32925-32934, 2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37859084

RESUMO

Development of miniature two-photon microscopy (m2PM) has made it possible to observe fine structure and activity of neurons in the brain of freely moving animals. However, the imaging field-of-view of existing m2PM is still significantly smaller than that of miniature single-photon microscopy. Here we report that, through the design of low-magnification objective, large field-of-view scan lens and small tilt angle microscanner, a 2.5-g m2PM achieved a field-of-view of 1000 × 788 µm2, comparable to that of a typical single-photon miniscope. We demonstrated its capability by imaging neurons, dendrites and spines in the millimeter field-of-view, and simultaneous recording calcium activities, through a gradient-index lens, of approximately 400 neurons in the dorsal hippocampal CA1 in a freely moving mouse. Integrated with a detachable 1.2-g fast z-scanning module, it enables a 1000 × 788 × 500 µm3 volumetric neuronal imaging in the cerebral cortex. Thus, millimeter FOV m2PM provides a powerful tool for deciphering neuronal population dynamics in experimental paradigms allowing for animal's free movement.


Assuntos
Encéfalo , Microscopia , Camundongos , Animais , Microscopia/métodos , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Cabeça , Neurônios/fisiologia , Neuroimagem
3.
Appl Opt ; 59(27): 8152-8159, 2020 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-32976395

RESUMO

A static solution to dynamic aberrations for conformal aircraft windows with a large range of look angles is reported. The solution uses the inner window surface and a fixed lens array near the image plane to correct the dynamic window aberrations at different look angles. The inner window surface is first used to balance the dynamic aberrations of the full field of regard. Then a lens array is implanted in front of the image, and the dynamic aberrations are corrected by designing the surface shape and rotation direction of each lens unit in the array. The principle of the solution is discussed, and a design example shows that the solution can realize the dynamic aberration correction introduced by the conformal window with a field of regard of ±42∘. Compared to other dynamic or static correctors, this solution takes into account the large field of regard, the light weight and the stability of the optoelectronic system.

4.
Appl Opt ; 57(30): 8861-8869, 2018 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-30461869

RESUMO

A method for the optimal design of multilayer diffractive optical elements (MLDOEs) with consideration of ambient temperature is presented to improve the image quality over the entire temperature range. The relationship between diffraction efficiency and temperature is analyzed, and an optimization process of surface relief height for the MLDOEs is given. A practical 3-5 µm athermal hybrid optical system with a double-layer diffractive optical element is designed in the temperature range from -20°C to 60°C, and the image quality of two hybrid optical systems with optimized MLDOE and original MLDOE is compared. The result shows that the comprehensive modulation transfer function is obviously improved in the whole working temperature range. This method can be used during the passive athermalization hybrid optical system design with MLDOEs.

5.
Appl Opt ; 56(10): 2826-2833, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28375249

RESUMO

We present a substrate material selection method for multilayer diffractive optical elements (MLDOEs) to obtain high polychromatic integral diffraction efficiency (PIDE) in a wide environmental temperature range. The extended expressions of the surface relief heights for the MLDOEs are deduced with consideration of the influence of the environmental temperature. The PIDE difference Δη¯(λ) and PIDE change factor F are introduced to select a reasonable substrate material combination. A smaller value of Δη¯(λ) or F indicates a smaller decrease of the PIDE in a wide temperature range, and the corresponding substrate material combination is better. According to the deduced relation, double-layer and three-layer DOEs with different combinations are discussed. The results show that IRG26 and zinc sulfide is the best substrate material combination in the infrared waveband for double-layer DOEs, and polycarbonate is more reasonable than polymethyl methacrylate as the middle filling optical material for three-layer DOEs when the two substrate materials are the same.

6.
Appl Opt ; 55(10): 2626-33, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-27139665

RESUMO

A static solution to aberrations and boresight error for tilted conformal aircraft windows at different look angles is reported. The solution uses the inner window surface to correct the window aberrations at a 0° look angle and uses fixed correctors behind the window to correct the residual window aberrations at other look angles. Then, the boresight error for the window at different look angles is corrected by tilting the fixed correctors. The principle of the solution is discussed, and a design example shows that the solution is effective in correcting the aberrations and boresight error for a tilted conformal aircraft window at different look angles.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA