Category Archives: Imaging

The crow as an animal model for neuroscience

Close to my apartment in the outskirts of Basel, green fields and some small woods lie basically in front of my house door. This is also where some flocks of crows gather around, partly searching the fields for food, partly … Continue reading

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Matlab code for control of a resonant scanning microscope

For control of resonant scanning 2P microscopes, my host lab uses a software that I have written in Matlab. Due to some coincidences, the software is based on Scanimage 4.2, a version developed few years ago for an interface with a Thorlabs scope and Thorlabs … Continue reading

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Preamplifier bandwidth & two ways of counting photons

For two-photon point scanning microscopy, the excitation laser is typically pulsing at a repetition rate of 80 MHz, that is one pulse each 12.5 ns. To avoid aliasing, it was suggested to synchronize the sampling clock to laser pulses. For this, it is important … Continue reading

Posted in Calcium Imaging, Imaging, Microscopy | Tagged , , , | 2 Comments

Large field of view microscopes for mouse brain imaging

For typical confocal or two-photon microscopes that maintain (sub)cellular resolution, a high-magnification objective is needed (typically 16x, 20x or 25x). This in turn limits the field of view (FOV) to ⌀ 1.0-1.5 mm. For imaging in the mouse brain cortex, which is … Continue reading

Posted in Calcium Imaging, Imaging, Microscopy | Tagged , , | 5 Comments

Spatial visualization of temporal components for neuronal activity imaging

The standard analysis workflow for neuronal activity imaging based on calcium signals is to 1) draw ROIs around putative neurons, 2) extract the average fluorescence time trace of this ROI, 3) work with this timetrace for subsequent analysis (principal components, … Continue reading

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Fast z-scanning using a voice coil motor

We just published a paper on fast remote z-scanning using a voice coil motor. For 2P calcium imaging. It’s a nice paper with some interesting technical details. The starting point was the remote z-scanning scheme used by Botcherby et al. (2012) from … Continue reading

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Modulating laser intensity on multiple timescales (x, y and z)

In point-scanning microscopy and especially when using resonant scanners, the intensity of the beam is typically modulated using a Pockels cell. For resonant scanning, the dwell time per micrometer is not constant along the scanned line, and one wants either to … Continue reading

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