In-depth activation of channelrhodopsin 2-sensitized excitable cells with high spatial resolution using two-photon excitation with a near-infrared laser microbeam.
Biophys J
; 95(8): 3916-26, 2008 Oct.
Article
em En
| MEDLINE
| ID: mdl-18621808
ABSTRACT
We used two-photon excitation with a near-infrared (NIR) laser microbeam to investigate activation of channelrhodopsin 2 (ChR2) in excitable cells for the first time to our knowledge. By measuring the fluorescence intensity of the calcium (Ca) indicator dye, Ca orange, at different wavelengths as a function of power of the two-photon excitation microbeam, we determined the activation potential of the NIR microbeam as a function of wavelength. The two-photon activation spectrum is found to match measurements carried out with single-photon activation. However, two-photon activation is found to increase in a nonlinear manner with the power density of the two-photon laser microbeam. This approach allowed us to activate different regions of ChR2-sensitized excitable cells with high spatial resolution. Further, in-depth activation of ChR2 in a spheroid cellular model as well as in mouse brain slices was demonstrated by the use of the two-photon NIR microbeam, which was not possible using single-photon activation. This all-optical method of identification, activation, and detection of ChR2-induced cellular activation in genetically targeted cells with high spatial and temporal resolution will provide a new method of performing minimally invasive in-depth activation of specific target areas of tissues or organisms that have been rendered photosensitive by genetic targeting of ChR2 or similar photo-excitable molecules.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação do Canal Iônico
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Fótons
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Raios Infravermelhos
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Lasers
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Neurônios
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article