Category Archives: Imaging

All-optical entirely passive laser scanning with MHz rates

Is it possible to let a laser beam scan over an angle without moving any mechanical parts to deflect the beam? It is. One strategy is to use a very short-pulsed laser beam: A short pulse width means a finite … Continue reading

Posted in Calcium Imaging, Imaging, Microscopy | Tagged , , | Leave a comment

How deconvolution of calcium data degrades with noise

How does the noisiness of the recorded calcium data affect the performance of spiking-inferring deconvolution algorithms? I cannot offer a rigorous treatment of this question, but some intuitive examples. The short answer: If a calcium transient is not visible at … Continue reading

Posted in Calcium Imaging, Data analysis, electrophysiology, Imaging, machine learning, Neuronal activity | Tagged , , , , | Leave a comment

A convolutional network to deconvolve calcium traces, living in an embedding space of statistical properties

As mentioned before (here and here), the spikefinder competition was set up earlier this year to compare algorithms that infer spiking probabilities from calcium imaging data. Together with Stephan Gerhard, a PostDoc in our lab, I submitted an algorithm based on convolutional networks. Looking … Continue reading

Posted in Calcium Imaging, Data analysis, electrophysiology, Imaging, machine learning, Neuronal activity | Tagged , , , , | Leave a comment

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

Posted in electrophysiology, Imaging, Neuronal activity, Uncategorized | Tagged , , | Leave a comment

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

Posted in Imaging, Microscopy | Tagged , , | Leave a comment

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