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Category Archives: Imaging
Heating up the objective for two-photon imaging
To image neurons in vivo with a large field of view, a large objective is necessary. This big piece of metal and glass is in indirect contact with the brain surface, with only water and maybe a cover slip in … Continue reading
Posted in Calcium Imaging, Imaging, Microscopy
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Interview with Bruno Pichler
Bruno Pichler studied medicine, obtained a PhD in neuroscience, worked in the labs of Arthur Konnerth, Tom Mrsic-Flogel and Troy Margrie, and was R&D manager at Scientifica, before founding his own company, INSS, “to provide the international neuroscience community with … Continue reading
Posted in Calcium Imaging, Data analysis, Imaging, Microscopy
Tagged interview, Microscopy, Two-photon
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Discrepancies between calcium imaging and extracellular ephys recordings
To record the activity from a population of neurons, calcium imaging and extracellular recordings with small electrodes are the two most widely used methods that are still able to disentangle the contributions from single units. Here, I would like to … Continue reading
Alignment tools
This blog posts covers some tools and techniques that I’m typically using to align two-photon microscopes. If you’re an expert, you will probably find nothing new, but if you haven’t been doing this for years, this might offer you some … Continue reading
Posted in Imaging, Microscopy
Tagged Alignment, laser scanning microscopy, Microscopy, Optics, Two-photon
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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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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
Whole-cell patch clamp, part 4: look and feel
In previous blog posts, I have been discussing some aspects of whole-cell patch clamp recordings ([1], [2], [3], [4]). Today, I will show some instructive videos that I recorded during experiments. I’m hoping that they will convey the look and feel … Continue reading
Posted in Calcium Imaging, electrophysiology, Imaging, Microscopy, Neuronal activity, zebrafish
Tagged electrophysiology, Microscopy, photons, zebrafish
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Alvarez lenses and other strangely shaped optical elements
In typical microscopes, lenses or mirrors are moved forth and back to change the position of their focus. Tunable lenses like the electro-tunable lens or the TAG lens, on the other hand, are deformed by an external force and thereby … Continue reading
A blog about neurophysiology 