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Tag Archives: photons
Interesting papers on online motion correction for calcium imaging
In a living animal, the brain is moving up and down in the skull. This brain motion can be due to breathing, heartbeat, tongue movements, but also due to changes of posture or running. For each brain region and posture, … Continue reading
Posted in Calcium Imaging, Data analysis, Imaging, machine learning, Microscopy, Neuronal activity, neuroscience
Tagged Calcium Imaging, Data analysis, Microscopy, photons, Scanning
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Ambizione fellowship and an open PhD position
I’m glad to share that I am going to start my own junior research group at the University of Zurich in March 2023! As an Ambizione fellow, I will receive funding for my own salary, some equipment, consumables and a … Continue reading
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
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
Posted in Calcium Imaging, Data analysis, Imaging, Microscopy, Neuronal activity
Tagged Calcium Imaging, Data analysis, Microscopy, photons, Scanning
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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
Posted in Calcium Imaging, Imaging, Microscopy, Neuronal activity
Tagged Calcium Imaging, Microscopy, photons, Scanning, zebrafish
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A practical guide for adaptive optics
There is no standard curriculum to learn practical procedures about microscopy: how to align a setup, how to identify misalignments, how to identify broken parts, where to buy components, how to check their performance, and much more. How to learn … Continue reading
Review: An artificial ground truth for calcium imaging
Selected paper: Charles, Song, Tank et al., Neural Anatomy and Optical Microscopy Simulation (NAOMi) for evaluating calcium imaging methods, bioRxiv (2019). What is the paper about? Calcium imaging is a central method to observe neuronal activity in the brain of … Continue reading
Posted in Calcium Imaging, Data analysis, Imaging, Microscopy, Neuronal activity, Reviews
Tagged Data analysis, Microscopy, photons, PSF, Scanning
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The cell-attached soundtrack of calcium imaging
Old-school electrophysiologists like to listen to the ephys signals during experiments. For example, this allows to precisely hear when the patch pipette approaches a target neuron. The technique is discussed in the Axon Guide: “Audio Monitor: Friend or Foe?”. The … Continue reading
Posted in Calcium Imaging, electrophysiology, Imaging, Neuronal activity, zebrafish
Tagged electrophysiology, Microscopy, photons, zebrafish
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Post-publication review: Somato-dendritic coupling of L5 neurons in V1
It requires more than a quick look at the abstract and the figures to fully understand a research paper and its limitations. One way to get there is to write a summary or critical review of a paper. In a contribution to … Continue reading
Posted in Calcium Imaging, electrophysiology, Microscopy, Reviews
Tagged Dendrites, electrophysiology, photons, theoretical neuroscience
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Photon yield and pulse dispersion
This case report describes how a two-photon microscope was found to come with a fluorescence yield that was lower than expected; how the underlying cause was found out in a systematic manner; and how the problem was solved. All approaches and solutions are specific for the microscope under question. However, I hope that this report (1) will inspire other people who are troubleshooting or optimizing their microscopes, (2) will help other people better understand two-photon microscopes and the relevance of technical details. Continue reading
A blog about neurophysiology 