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Category Archives: Microscopy
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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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
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
Open access 3D electron microscopy datasets of brains
One of the coolest technical developments in neuroscience during the last decade has been driven by 3D electron microscopy (3D EM). This allowed to cut large junks of small brains (or small junks of big brains) into 8-50 nm thick … Continue reading
Posted in Data analysis, machine learning, Microscopy, Network analysis, zebrafish
Tagged Data analysis, Microscopy, Network analysis, zebrafish
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Springtime for two-photon microscopy
Today, the fields and forests around Basel are full of flowers that try to disseminate their pollen. Fixed pollen are, apart from sub-diffraction beads and the convallaria rhizome, one of the most commonly used test/reference samples for fluorescence microscopy. This … Continue reading
Can two-photon scanning be too fast?
The following back-of-the-envelope calculations do not lead to any useful result, but you might be interested in reading through them if you want to get a better understanding of what happens during two-photon excitation microscopy. The basic idea of two-photon microscopy … Continue reading
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
Whole-cell patch clamp, part 2: Line-frequency pick-up via the perfusion system
With the experience of more than one year of patching (although you might say that this is not a lot), I’m now used to problems that I can solve after some time, but without being able to tell what the problem has … Continue reading