Category Archives: Data analysis

Interesting papers on astrocyte ultrastructure and function

Astrocytes are brain cells that are often completely overlooked and dismissed or, in the opposite extreme, presented as mysterious devices that somehow solve all problems of computational neuroscience. The truth is somewhere in the middle, but it is not clear yet where exactly. First of all, we still do not understand even the basic mechanistic rules by which individual astrocytes operate. For neurons, we have precise, often even mathematical ideas how they receive input via synapses, how they depolarize, and how depolarizations propagate to the soma and elicit action potentials. For astrocytes, this mechanistic book of rules is still missing – and this gap limits our ability to interpret experiments or build coherent theories. Continue reading

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Displaying the hippocampus as EM image on the office wall

One of the most amazing methods in modern neuroscience is dense volumetric electron microscopy of the brain. I have mentioned some openly accessible datasets before (see my previous blog post), but many additional datasets have been released since then – … Continue reading

Posted in Data analysis, hippocampus, Imaging, Microscopy, Network analysis, neuroscience | Tagged , | 3 Comments

Interesting papers on the role of cell organelles of neuronal dendrites in calcium signaling

Researchers utilize calcium imaging to track neuronal activity in the brain, highlighting the role of calcium as a signaling molecule. Recent studies investigate intracellular calcium dynamics, particularly its coupling between organelles and its influence on synaptic plasticity in dendrites. Findings emphasize the necessity of in vivo methods for accurate insights into neuronal behavior. Continue reading

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Interesting papers on VIP interneurons in cortex and hippocampus

Interneurons are inhibitory neurons in the brain that are thought to shape the computations performed by principal cells. The effects of inhibition can be rather diverse, depending on which neurons – or which parts of a neuron (dendrites, soma, or … Continue reading

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Accurately computing noise levels for calcium imaging data

It is fascinating how much data quality can vary between different calcium imaging data sets. In this blog post, I will discuss a metric to quantify and compare data quality and in particular shot noise between calcium imaging datasets. This … Continue reading

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

Open PhD position in my research group

Are you a finishing Master’s student with a quantitative background and are interested in neuroscience? This is your opportunity. Project: You will be supervised by Dr. Peter Rupprecht and Prof. Fritjof Helmchen at the Brain Research Institute, University of Zurich. … Continue reading

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

How to compute ΔF/F from calcium imaging data

Many neuroscientists use calcium imaging to record the activity from neurons (or other cells in the brain). The video below was recorded by Sian Duss and me in hippocampal CA1 pyramidal cells in mice. To make calcium imaging traces comparable … Continue reading

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Online spike inference with GCaMP8

Calcium imaging is used to record the activity of neurons in living animals. Often, these activity patterns are analyzed after the experiments to investigate how the brain works. Alternatively, it is also possible to extract the activity patterns in real … Continue reading

Posted in Brain machine interface, Calcium Imaging, closed-loop, Data analysis, electrophysiology, Imaging, machine learning, neuroscience | Tagged , , , , , | Leave a comment

Detecting single spikes from calcium imaging

There are two mutually exclusive holy grails of calcium imaging: First, recording from the highest number of neurons simultaneously. Second, detecting spike patterns with single-spike precision. This blog post focuses on the latter. Many studies have claimed to demonstrate single-spike … Continue reading

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Non-linearity of calcium indicators: history-dependence of spike reporting

Calcium indicators are used to report the calcium concentration inside single cells. In neurons, calcium imaging can be used as a readout of neuronal activity (action potentials). However, some calcium indicators like GCaMP transform the calcium concentration of a cell … Continue reading

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