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A multimodal micro-optrode combining field and single unit recording, multispectral detection and photolabeling capabilities.

Dufour S, Lavertu G, Dufour-Beauséjour S, Juneau-Fecteau A, Calakos N, Deschênes M, Vallée R, De Koninck Y - PLoS ONE (2013)

Bottom Line: Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm).It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells.The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system.

View Article: PubMed Central - PubMed

Affiliation: Unité de neurosciences cellulaires et moléculaires, Institut universitaire en santé mentale de Québec, Québec, Québec, Canada.

ABSTRACT
Microelectrodes have been very instrumental and minimally invasive for in vivo functional studies from deep brain structures. However they are limited in the amount of information they provide. Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm). The probe enables optical separation from individual cells in transgenic mice expressing multiple fluorescent proteins in distinct populations of neurons within the same deep brain nucleus. It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells. While metal coating did not significantly improve the optical separation capabilities of the microprobe, the combination of metal on the outside of the probe and of a hollow core within the fiber yields a microelectrode enabling simultaneous single unit and population field potential recordings. The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system.

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Photoconversion of mEOS.A–B) Images at different time points of a mEOS2 expressing cell during UV-induced photoconversion. UV illumination with the probe causes an increase in red fluorescence (A) and a decrease in green signal (B). C) Red and green emission of a cell during photo-conversion as a function of time. The region of interest taken into account is shown in (A) (white circle). Note that only two time points were measured for the green signal. Change in background fluorescence around the cell is shown in black.
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pone-0057703-g003: Photoconversion of mEOS.A–B) Images at different time points of a mEOS2 expressing cell during UV-induced photoconversion. UV illumination with the probe causes an increase in red fluorescence (A) and a decrease in green signal (B). C) Red and green emission of a cell during photo-conversion as a function of time. The region of interest taken into account is shown in (A) (white circle). Note that only two time points were measured for the green signal. Change in background fluorescence around the cell is shown in black.

Mentions: To test whether the microprobe could be used to change emission properties of photo-switchable fluorescent proteins, we illuminated mEOS2 transected cells with UV light injected through the microprobe. Intensity at probe tip used to convert emission properties was estimated to 2 mW/mm2. Results show a significant increase in red signal and a decrease in green fluorescence of an isolated mEOS2 expressing neuron (Fig. 3). This indicates that the microprobe is suitable to label by photo-conversion or photo-activation in vivo recorded cells.


A multimodal micro-optrode combining field and single unit recording, multispectral detection and photolabeling capabilities.

Dufour S, Lavertu G, Dufour-Beauséjour S, Juneau-Fecteau A, Calakos N, Deschênes M, Vallée R, De Koninck Y - PLoS ONE (2013)

Photoconversion of mEOS.A–B) Images at different time points of a mEOS2 expressing cell during UV-induced photoconversion. UV illumination with the probe causes an increase in red fluorescence (A) and a decrease in green signal (B). C) Red and green emission of a cell during photo-conversion as a function of time. The region of interest taken into account is shown in (A) (white circle). Note that only two time points were measured for the green signal. Change in background fluorescence around the cell is shown in black.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3585187&req=5

pone-0057703-g003: Photoconversion of mEOS.A–B) Images at different time points of a mEOS2 expressing cell during UV-induced photoconversion. UV illumination with the probe causes an increase in red fluorescence (A) and a decrease in green signal (B). C) Red and green emission of a cell during photo-conversion as a function of time. The region of interest taken into account is shown in (A) (white circle). Note that only two time points were measured for the green signal. Change in background fluorescence around the cell is shown in black.
Mentions: To test whether the microprobe could be used to change emission properties of photo-switchable fluorescent proteins, we illuminated mEOS2 transected cells with UV light injected through the microprobe. Intensity at probe tip used to convert emission properties was estimated to 2 mW/mm2. Results show a significant increase in red signal and a decrease in green fluorescence of an isolated mEOS2 expressing neuron (Fig. 3). This indicates that the microprobe is suitable to label by photo-conversion or photo-activation in vivo recorded cells.

Bottom Line: Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm).It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells.The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system.

View Article: PubMed Central - PubMed

Affiliation: Unité de neurosciences cellulaires et moléculaires, Institut universitaire en santé mentale de Québec, Québec, Québec, Canada.

ABSTRACT
Microelectrodes have been very instrumental and minimally invasive for in vivo functional studies from deep brain structures. However they are limited in the amount of information they provide. Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm). The probe enables optical separation from individual cells in transgenic mice expressing multiple fluorescent proteins in distinct populations of neurons within the same deep brain nucleus. It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells. While metal coating did not significantly improve the optical separation capabilities of the microprobe, the combination of metal on the outside of the probe and of a hollow core within the fiber yields a microelectrode enabling simultaneous single unit and population field potential recordings. The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system.

Show MeSH
Related in: MedlinePlus