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Peter Rupprecht

@ptrrupprecht.bsky.social

630 followers 550 following 69 posts

Junior group leader in neuroscience - calcium imaging, ephys, plasticity, microscopy, neurons & astrocytes, data analysis. PhD with Rainer Friedrich, postdoc with Fritjof Helmchen. https://www.gcamp6f.com/

www.gcamp6f.com

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Peter Rupprecht @ptrrupprecht.bsky.social · Mar 11

Are you using GCaMP8 or are planning to switch from GCaMP6? Then check out this new preprint from our lab! www.biorxiv.org/content/10.1...

- Calcium imaging
- GCaMP8 vs. GCaMP6
- Spike inference
- Imaging + ephys ground truth

With F. Helmchen, K. Svoboda, M. Rozsa & X. Fang.

Three images with figure excerpts from the paper, highlighting 1) single-spike detection analysis, 2) autocalibration analysis, and 3) non-linearity of calcium-to-fluorescence transfer functions and their effect on the reporting of complex spiking events.

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Peter Rupprecht @ptrrupprecht.bsky.social · 5d

It's a great paper - congrats!

Peter Rupprecht @ptrrupprecht.bsky.social · 9d

This objective was designed for 2P imaging. For 1P imaging, I believe that there are still some technical problems to be solved. Perhaps @voigtvision.bsky.social or @nvladimus.bsky.social can tell you more!

Peter Rupprecht @ptrrupprecht.bsky.social · 10d

I'm using it mostly for 2P imaging, but it should also be relevant for expansion microscopy: Olympus XLPLN10XSVMP with NA 0.6, WD 8 mm: evidentscientific.com/en/objective...

Objective Finder | Evident Scientific | Olympus

Select the right lens for your application from our broad line of Olympus microscope objectives.

evidentscientific.com

Peter Rupprecht @ptrrupprecht.bsky.social · 10d

Reflective Schmidt objectives with high NA and long WD: www.nature.com/articles/s41...
@voigtvision.bsky.social

Reflective multi-immersion microscope objectives inspired by the Schmidt telescope - Nature Biotechnology

Imaging of large, cleared samples in diverse media is achieved using a mirror objective.

www.nature.com

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Reposted by Peter Rupprecht

Alexander Mathis @trackingskills.bsky.social · 15d

Understanding behavior requires datasets that capture humans while carrying out complex tasks. The kitchen is an excellent environment for assessing human motor and cognitive function, as many complex actions are naturally exhibited in kitchens from chopping to 🧽!

arxiv.org/abs/2506.01608

EPFL-Smart-Kitchen-30: Densely annotated cooking dataset with 3D kinematics to challenge video and language models

arxiv.org

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Reposted by Peter Rupprecht

Adrien Peyrache @apeyrache.bsky.social · 21d

« Diverse calcium dynamics underlie place field formation in hippocampal CA1 pyramidal cells. »

A fundamental study now published @elife.bsky.social

elifesciences.org/reviewed-pre...

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Peter Rupprecht @ptrrupprecht.bsky.social · Aug 14

New blog post about a fun project where I tried to beautify my office by putting a poster of the hippocampal column onto my walls: gcamp6f.com/2025/08/13/d...
EM pictures from this paper: www.biorxiv.org/content/10.1... from the lab of @helenelab.bsky.social

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…

gcamp6f.com

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Peter Rupprecht @ptrrupprecht.bsky.social · Aug 11

New blog post, where I review some recent interesting papers on the role of cell organelles for neuronal calcium signaling: gcamp6f.com/2025/08/11/i...
Featuring work by @lorenabenedetti.bsky.social, O'Hare et al. and Lin et al.!

Interesting papers on the role of cell organelles in neuronal dendrites for 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, par…

gcamp6f.com

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Peter Rupprecht @ptrrupprecht.bsky.social · Jul 31

I also wonder whether you have observed any signs of cytotoxicity or fluorophore aggregates?

Peter Rupprecht @ptrrupprecht.bsky.social · Jul 31

This OCaMP sensor looks quite promising! Looking forward to trying it out!

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Reposted by Peter Rupprecht

Abhi Aggarwal @abhiaggarwal.bsky.social · Jul 31

#OCaMP is now on bioRxiv and reagents are available on #Addgene! 🧪

A sensitive orange fluorescent calcium ion indicator for imaging neural activity

www.biorxiv.org/content/10.1...

A sensitive orange fluorescent calcium ion indicator for imaging neural activity

Genetically encoded calcium indicators (GECIs) are vital tools for fluorescence-based visualization of neuronal activity with high spatial and temporal resolution. However, current highest-performance...

www.biorxiv.org

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Peter Rupprecht @ptrrupprecht.bsky.social · Jul 3

Thanks, it looks very interesting!

The first comment of reviewer #1 is also "interesting", asking for the "connectome" of VIP neurons for the revised manuscript ;-)

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Peter Rupprecht @ptrrupprecht.bsky.social · Jun 23

New blog post with a review of interesting papers on VIP interneurons in cortex and hippocampus: gcamp6f.com/2025/06/23/i...
Covering work from @koenvervaeke.bsky.social's lab with @mateneubrandt.bsky.social, Yoav Adam's lab and Bernardo Rudy's lab.

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Reposted by Peter Rupprecht

Matthijs Dorst @mattneuro.bsky.social · Jun 13

#neuroskyence folks: as my postdoc grant is running out soon, I am looking for new opportunities in systems neuroscience!

Keywords: patch clamp ephys, opto, mouse behavior, (in vivo) voltage imaging. Would love to return to the Basal Ganglia.

Sharing appreciated, and happy #FluorescenceFriday !

Brightly labelled pyramidal cells in the mouse retrosplenial cortex. Blood vessels are visible of various thicknesses in darker colours.

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Reposted by Peter Rupprecht

Martin Fuhrmann @martinfuhrmann.bsky.social · Jun 1

It is out! Read how you achieve 1.7 mm deep 3-photon imaging in prefrontal cortex with dendritic spine resolution over a week.
www.nature.com/articles/s42...

Three-photon in vivo imaging of neurons and glia in the medial prefrontal cortex with sub-cellular resolution - Communications Biology

Three-photon in vivo imaging provides access to medial prefrontal cortex, hippocampus and spinal cord in mice at up to 1.7 mm depth of neurons, dendrites, spines, astrocytes and microglia.

www.nature.com

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Reposted by Peter Rupprecht

Friedemann Zenke @fzenke.bsky.social · May 27

1/6 Why does the brain maintain such precise excitatory-inhibitory balance?
Our new preprint explores a provocative idea: Small, targeted deviations from this balance may serve a purpose: to encode local error signals for learning.
www.biorxiv.org/content/10.1...
led by @jrbch.bsky.social

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Peter Rupprecht @ptrrupprecht.bsky.social · May 27

Yes, this is great work! An important aspect is that it clearing of *archival* FFPE tissues over 10 years old. This method suddenly makes such biomedical archives much more valuable.

Reposted by Peter Rupprecht

voigtvision.bsky.social @voigtvision.bsky.social · May 27

The culmination of years of hard work by Anna Maria Reuss & Co: aDISCO - a protocol for clearing & antibody-staining human formalin-fixed paraffin-embedded (FFPE) tissue! With lots of @mesospim.bsky.social #lightsheet #Microscopy @ptrrupprecht.bsky.social & many more!
www.biorxiv.org/content/10.1...

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Peter Rupprecht @ptrrupprecht.bsky.social · May 21

Could it also be feedback inhibition?

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Reposted by Peter Rupprecht

Benjamin Judkewitz @benjulab.bsky.social · May 12

Introducing warpfield, an open source Python library for GPU-accelerated non-rigid 3D registration. Warps and aligns gigavoxel volumes within seconds (not hours). For 3D microscopy, region-to-region and cell-to-cell matching.
A collaboration with @mh123.bsky.social 🚀
github.com/danionella/w...

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Peter Rupprecht @ptrrupprecht.bsky.social · May 6

Our study on spike inference from calcium imaging data in spinal cord is now published at the Journal of Neuroscience @sfnjournals.bsky.social ! 🥳With open datasets and public reviews: www.jneurosci.org/content/45/1...

Spike Rate Inference from Mouse Spinal Cord Calcium Imaging Data

Calcium imaging is a key method to record the spiking activity of identified and genetically targeted neurons. However, the observed calcium signals are only an indirect readout of the underlying elec...

www.jneurosci.org

Peter Rupprecht @ptrrupprecht.bsky.social · May 6

Thanks! I knew this one and was curious about hippocampus-specific astrocytes. But I'll check the paper again!

Peter Rupprecht @ptrrupprecht.bsky.social · Apr 26

(at least it's not possible in the recordings that I'm aware of)

Peter Rupprecht @ptrrupprecht.bsky.social · Apr 26

Yes, I believe it's hard. There are only some dozen people in who could do these in vivo whole-cell recordings. In addition, in vivo there are so many EPSPs that you cannot detect single ones. It is currently not possible to reliably detect individual EPSPs in in vivo recordings.

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Peter Rupprecht @ptrrupprecht.bsky.social · Apr 26

The work of David McCormick (e.g., doi.org/10.1146/annu...) goes into this direction, but maybe this deviates already too much from your original question ;-)

Neuromodulation of Brain State and Behavior | Annual Reviews

Neural activity and behavior are both notoriously variable, with responses differing widely between repeated presentation of identical stimuli or trials. Recent results in humans and animals reveal th...

doi.org