Guido Meijer
@guidomeijer.com
👨🔬 Neuroscientist at the Donders Institute in the Battaglia lab.
🧠 Previously: International Brain Laboratory
Using Neuropixels and virtual-reality to understand how the brain creates internal models of the world.
www.guidomeijer.com
🧠 Previously: International Brain Laboratory
Using Neuropixels and virtual-reality to understand how the brain creates internal models of the world.
www.guidomeijer.com
The Power Pixels pipeline just keeps getting better! The latest update comes with:
- OpenEphys support
- AP_Histology support
- automatic high-frequency noise reduction
- NWB format export option
- zarr compression of raw data
And, most importantly: a cool new logo!
github.com/NeuroNetMem/...
- OpenEphys support
- AP_Histology support
- automatic high-frequency noise reduction
- NWB format export option
- zarr compression of raw data
And, most importantly: a cool new logo!
github.com/NeuroNetMem/...
November 11, 2025 at 11:25 AM
The Power Pixels pipeline just keeps getting better! The latest update comes with:
- OpenEphys support
- AP_Histology support
- automatic high-frequency noise reduction
- NWB format export option
- zarr compression of raw data
And, most importantly: a cool new logo!
github.com/NeuroNetMem/...
- OpenEphys support
- AP_Histology support
- automatic high-frequency noise reduction
- NWB format export option
- zarr compression of raw data
And, most importantly: a cool new logo!
github.com/NeuroNetMem/...
A note about colors 🌈 Imagine you made eight figures and your PI asks you to change the color of an element you've consistently plotted green into orange. If you define your colors in the plotting function you only have to change it there and rerun the plotting scripts, this save a lot of time!
October 16, 2025 at 8:26 AM
A note about colors 🌈 Imagine you made eight figures and your PI asks you to change the color of an element you've consistently plotted green into orange. If you define your colors in the plotting function you only have to change it there and rerun the plotting scripts, this save a lot of time!
The font size of each plot element can be easily set with seaborn. Write a function like this that sets the font size and any other style element you like to have in all your plots and the function each time before plotting (link to the code in the last post).
October 16, 2025 at 8:26 AM
The font size of each plot element can be easily set with seaborn. Write a function like this that sets the font size and any other style element you like to have in all your plots and the function each time before plotting (link to the code in the last post).
Want to make publication-ready figures come straight from Python without having to do any manual editing? Are you fed up with axes labels being unreadable during your presentations? Follow this short tutorial including code examples! 👇🧵
October 16, 2025 at 8:26 AM
Want to make publication-ready figures come straight from Python without having to do any manual editing? Are you fed up with axes labels being unreadable during your presentations? Follow this short tutorial including code examples! 👇🧵
I love how they came up with all this random stuff but for this one area they were like "I really don't know, just put a question mark"
October 5, 2025 at 10:40 AM
I love how they came up with all this random stuff but for this one area they were like "I really don't know, just put a question mark"
I don't know why people say X is going down the drain, my last post got lovely replies like this one:
September 12, 2025 at 12:52 PM
I don't know why people say X is going down the drain, my last post got lovely replies like this one:
This subspace is an extra dimension which allows serotonin to modulate information to create new, orthogonalized, representations of the environment. This can be used to relay information regarding internal state, or facilitate the rapid updating of representations during flexible behavior. (7/9)
August 5, 2025 at 12:32 PM
This subspace is an extra dimension which allows serotonin to modulate information to create new, orthogonalized, representations of the environment. This can be used to relay information regarding internal state, or facilitate the rapid updating of representations during flexible behavior. (7/9)
How is it possible that serotonin modulates neural activity across the brain but does not affect behavior? We found that the serotonergic modulation occurs in a subspace which is orthogonal to the choice axis. We call this the "neuromodulatory subspace". (6/9)
August 5, 2025 at 12:32 PM
How is it possible that serotonin modulates neural activity across the brain but does not affect behavior? We found that the serotonergic modulation occurs in a subspace which is orthogonal to the choice axis. We call this the "neuromodulatory subspace". (6/9)
We expected that serotonin stimulation would change how mice incorporate a prior in their decision making. However, in the steering wheel task of the International Brain Laboratory there was no effect of 5-HT stimulation whatsoever. 🤔 (5/9)
August 5, 2025 at 12:32 PM
We expected that serotonin stimulation would change how mice incorporate a prior in their decision making. However, in the steering wheel task of the International Brain Laboratory there was no effect of 5-HT stimulation whatsoever. 🤔 (5/9)
On this website you can interactively explore our data and have a look at how serotonin modulates your favorite region!
atlas.internationalbrainlab.org?buckets=meij...
(4/9)
atlas.internationalbrainlab.org?buckets=meij...
(4/9)
August 5, 2025 at 12:32 PM
On this website you can interactively explore our data and have a look at how serotonin modulates your favorite region!
atlas.internationalbrainlab.org?buckets=meij...
(4/9)
atlas.internationalbrainlab.org?buckets=meij...
(4/9)
We found widespread modulation of neural dynamics across all recorded brain regions. Single neurons were either excited or inhibited by 5-HT. Regions like the PAG, mPFC and OFC were excited by serotonin whereas the hippocampus was suppressed. Regions in the middle were more balanced. (3/9)
August 5, 2025 at 12:32 PM
We found widespread modulation of neural dynamics across all recorded brain regions. Single neurons were either excited or inhibited by 5-HT. Regions like the PAG, mPFC and OFC were excited by serotonin whereas the hippocampus was suppressed. Regions in the middle were more balanced. (3/9)
These are all the Neuropixel insertions we made across the mouse brain while optogenetically stimulating serotonergic neurons in the dorsal raphe nucleus with a fiber (thick grey tube). We recorded ~7500 neurons in total across a large number of brain regions 🧠 (2/9)
August 5, 2025 at 12:32 PM
These are all the Neuropixel insertions we made across the mouse brain while optogenetically stimulating serotonergic neurons in the dorsal raphe nucleus with a fiber (thick grey tube). We recorded ~7500 neurons in total across a large number of brain regions 🧠 (2/9)
The PhD students started writing motivational quotes on the whiteboard
April 9, 2025 at 12:50 PM
The PhD students started writing motivational quotes on the whiteboard
In my spare time I'm a singer-songwriter and just recorded my first couple of songs!
January 11, 2025 at 3:34 PM
In my spare time I'm a singer-songwriter and just recorded my first couple of songs!
People who are still posting science content on X:
January 7, 2025 at 2:01 PM
People who are still posting science content on X:
Yesterday I made a screenshot of my recording because it looked so nice, forgot about it, and then freaked out because I thought SpikeGLX had frozen 🫠
November 15, 2024 at 8:45 AM
Yesterday I made a screenshot of my recording because it looked so nice, forgot about it, and then freaked out because I thought SpikeGLX had frozen 🫠
It includes pre-processing, spike sorting, neuron-level quality control metrics (IBL & BombCell), synchronization between multiple probes, compression of raw data, probe tracing (Universal Probe Finder) and ephys-to-histology alignment.
November 13, 2024 at 10:33 AM
It includes pre-processing, spike sorting, neuron-level quality control metrics (IBL & BombCell), synchronization between multiple probes, compression of raw data, probe tracing (Universal Probe Finder) and ephys-to-histology alignment.
Starter packs are great and all but don't miss out on the Spotify playlist I made for all my fellow postdocs!
Link 👉 open.spotify.com/playlist/2M2...
Link 👉 open.spotify.com/playlist/2M2...
November 12, 2024 at 8:03 AM
Starter packs are great and all but don't miss out on the Spotify playlist I made for all my fellow postdocs!
Link 👉 open.spotify.com/playlist/2M2...
Link 👉 open.spotify.com/playlist/2M2...
Absolutely love this paper! The subdivision of higher visual cortex in mice into a bunch of distinct areas (LM, AL, PM, etc.) is wrong, it's all just V2. Makes much more sense to me!
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
November 7, 2024 at 5:37 PM
Absolutely love this paper! The subdivision of higher visual cortex in mice into a bunch of distinct areas (LM, AL, PM, etc.) is wrong, it's all just V2. Makes much more sense to me!
www.biorxiv.org/content/10.1...
www.biorxiv.org/content/10.1...
We're happy to share the extension of the ZETA-test into a full-fledged statistical family. 📈👨👩👧👦
Now you can also include more cells in your GCaMP data, and perform two-sample comparisons, all binning-free!
With Jorrit Montijn and Alexander Heimel.
www.biorxiv.org/content/10.1...
#neuroscience
Now you can also include more cells in your GCaMP data, and perform two-sample comparisons, all binning-free!
With Jorrit Montijn and Alexander Heimel.
www.biorxiv.org/content/10.1...
#neuroscience
November 3, 2023 at 12:05 PM
We're happy to share the extension of the ZETA-test into a full-fledged statistical family. 📈👨👩👧👦
Now you can also include more cells in your GCaMP data, and perform two-sample comparisons, all binning-free!
With Jorrit Montijn and Alexander Heimel.
www.biorxiv.org/content/10.1...
#neuroscience
Now you can also include more cells in your GCaMP data, and perform two-sample comparisons, all binning-free!
With Jorrit Montijn and Alexander Heimel.
www.biorxiv.org/content/10.1...
#neuroscience
Are you on a budget? The repurposed hard drive method only has to cost 15 bucks! If you have an old hard drive laying around and your rig already has a stereoscope and micromanipulator you just need this: https://www.thorlabs.com/thorproduct.cfm?partnumber=LF1P
July 11, 2023 at 4:00 PM
Are you on a budget? The repurposed hard drive method only has to cost 15 bucks! If you have an old hard drive laying around and your rig already has a stereoscope and micromanipulator you just need this: https://www.thorlabs.com/thorproduct.cfm?partnumber=LF1P