Author Archives: P.T.R. Rupprecht

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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Protocols to check the performance of your multiphoton microscope

In an exceptionally useful paper, Lees et al. provide a set of protocols for checking the performance of your multiphoton microscope: Standardized measurements for monitoring and comparing multiphoton microscope systems (link to preprint). The paper covers the following procedures: Check … Continue reading

Posted in Calcium Imaging, Microscopy, Reviews | Tagged , , | 2 Comments

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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How to use Google Scholar as a neuroscientist

Google Scholar is a search engine for scientific publications. There are alternatives like PubMed (not a search engine but a database, often used in the medical field), Semantic Scholar (also a database, but with richer annotations), Citation Gecko (to discover … Continue reading

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Annual report of my intuition about the brain (2024)

The brain is a complex system that cannot be understood by a strictly structured approach. Knowledge must grow organically, and a systematic approach can sometimes hinder understanding. In formal education, this truth is often hidden because curricula and instructors provide the structuring of knowledge already. But when it comes to acquiring new knowledge and insight, rather than merely processing and assembling pre-existing knowledge, this systematic approach must be continuously interrupted and re-invented to enable real progress. Continue reading

Posted in Data analysis, Neuronal activity, neuroscience, Reviews | Tagged , , , , , | 9 Comments

A resource paper for building two-photon microscopes

The article discusses the challenges in learning to build microscopes, highlighting a manuscript by Schottdorf et al. that offers practical assembly instructions and rationale based on years of successful use. It emphasizes useful insights, such as design suggestions, performance compromises, and comprehensive documentation on GitHub, making it a valuable resource for researchers. Continue reading

Posted in Calcium Imaging, Imaging, Microscopy, neuroscience | Tagged , , , , , , | 1 Comment

Spike inference with GCaMP8: new pretrained models available

Calcium imaging is only an indirect readout of neuronal activity via fluorescence signals. To estimate the true underlying firing rates of these neurons, methods for “spike inference” have been developed. They are useful to denoise calcium imaging data and make … Continue reading

Posted in Calcium Imaging, Data analysis, Imaging, machine learning, Network analysis, Neuronal activity | Tagged , , , , | 4 Comments