Author Archives: P.T.R. Rupprecht

Self-supervised denoising of calcium imaging data

This blog post is about algorithms based on deep networks to denoise raw calcium imaging movies. More specifically, I will write about the difficulties to interprete their outputs, and on how to address these limitations in future work. I will … Continue reading

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

Video introduction to CASCADE

A video with tutorial on CASCADE, a supervised method to infer spike rates from calcium imaging data. Continue reading

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

Simple geometrical optics to understand and design point-scanning microscopes

Custom-built microscopes have become more and more sophisticated over the last years to provide a larger FOV, better resolution through some flavor of adaptive optics or simply more neurons simultaneously. Professional optical engineers are hired to design the ideal lens … Continue reading

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

Public peer review files

Peer-review is probably the most obscure part of the publication of scientific results. In this blog post, I would like to make the point that the best way to learn about it – except by being directly involved – is … Continue reading

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Annual report of my intuition about the brain (2021)

How does the brain work and how can we understand it? I want to make it a habit to report some of the thoughts about the brain that marked me most during the past twelve month at the end of … Continue reading

Posted in machine learning, Network analysis, Review | Tagged , , , | 4 Comments

Large-scale calcium imaging & noise levels

Calcium imaging based on two-photon scanning microscopy is a standard method to record the activity of neurons in the living brain. Due to the point-scanning approach, sampling speed is limited and the dwell time on a single neuron reduces with … Continue reading

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5 reasons why to use Cascade for spike inference

Our paper on A database and deep learning toolbox for noise-optimized, generalized spike inference from calcium imaging is out now in Nature Neuroscience. It consists of a large and diverse ground truth database with simultaneous calcium imaging and juxtacellular recordings … Continue reading

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Fast scanning, triplet states and photon yield

In point-scanning microscopy like two-photon or confocal microscopy, a focused laser beam is scanned across the field of view and thereby sequentially recovers an image of the object. In this blog post, I will discuss the idea that scanning faster … Continue reading

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Research and Intuition

So far I was very fortunate with my scientific long-term mentors and supervisors: both of them are kind, open, creative and stunningly intelligent. I could not wish for more. However, when asked about a role model, I would mention a … Continue reading

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Online spike rate inference with Cascade

To infer spike rates from calcium imaging data for a time point t, knowledge about the calcium signal both before and after time t is required. Our algorithm Cascade (Github) uses by default a window that is symmetric in time … Continue reading

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