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Tag Archives: Data analysis
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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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
Matlab magic spells
Most neuroscientists who analyze their data themselves use either Matlab or Python or both – the use of R is much less common than in other fields of biology. I’ve been working with Matlab on a daily basis for >10 … Continue reading
Annual report of my intuition about the brain (2019)
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
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: “Precise excitation-inhibition balance controls gain and timing in the hippocampus”
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 go there is to write a summary or critical review of a paper. In a contribution to … Continue reading
The power of correlation functions
During my physics studies, I got to know several mathematical tools that turned out to be extremely useful to describe the world and to analyze data, for example vector calculus, fourier analysis or differential equations. Another tool that I find … Continue reading
Posted in Calcium Imaging, Data analysis, electrophysiology
Tagged Data analysis, electrophysiology, Matlab, Microscopy, Python
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Blue light-induced artifacts in glass pipette-based recording electrodes
Recently, I was carrying out whole-cell voltage-clamp and LFP recordings with simultaneous optogenetic activation of a channelrhodopsin using blue light. Whole-cell voltage clamp techniques can record the input currents seen by a neuron (previously on this blog [1], [2]); an … Continue reading
Posted in Data analysis, electrophysiology, Neuronal activity
Tagged Data analysis, electrophysiology
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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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How well do CNNs for spike detection generalize to unseen datasets?
Some time ago, Stephan Gerhard and I have used a convolutional neural network (CNN) to detect neuronal spikes from calcium imaging data. (I have mentioned this before, here, here, and on Github.) This method is covered by the spikefinder paper … Continue reading
A blog about neurophysiology 