Florian Kämpf

Some fly neurons are “dimorphic”, existing in both males and females but connecting to different neighboring neurons. Neighbors may be “isomorphic”, the same in both male and female; or sex specific; or dimorphic themselves. Here's an example, the type AOTU012, present in left and right instances.

We provide the most detailed picture yet of the result of sexually dimorphic development of the nervous system. The dataset should be a game-changer for researchers exploring behaviour, circuits & brain wiring! Check out male-cns.janelia.org.

Huge thanks to our amazing team of co-authors! 10/10

Statistical analysis of connectivity within the central brain shows that around 6.5% of synaptic connections in the male and 1.3% of connections in the female are dimorphic. In the male, sex-specific circuit elements form highly interconnected clusters with similar connectivity. 9/10

We explore #dimorphism across sensory modalities (visual and auditory systems, gustation and olfaction) and find, for example, a putative functional “love spot” involving male-specific neurons. 8/10

Comparing the EM neurons to light microscopy datasets of fruitless and doublesex expression, we annotated the putative expression pattern of these genes for both the male and female connectomes. 7/10

We cross-matched neurons and identified over 7k isomorphic, 114 sexually dimorphic, 262 male- and 69 female-specific cell types. In total, these neurons make up 4.8% and 2.4% of the male and female brain, respectively. 6/10

As the first (and so far, only) male brain, we compared this connectome to the previously published #FlyWire #FAFB female dataset to investigate the structural differences across male and female brain connectomes. 5/10

Using these annotations we ran end-to-end analyses going from sensory inputs all the way to motor outputs. This showed, for instance, that ascending and descending neurons are not passive relays but likely perform complex transformations of information flowing between brain and nerve cord. 4/10

This is the first completely proofread connectome of a nervous system (brain + nerve cord) for an adult animal with complex behaviour: 167k neurons with rich annotations (classes, cell types, developmental lineages, …) to help explore the dataset and 125M synaptic connections between them. 3/10

A hugely successful collaboration between @janelia-flyem.bsky.social @camzoology.bsky.social @mrclmb.bsky.social with @beckett14.bsky.social @mmcosta.bsky.social Philipp Schlegel (not on Bluesky) and many others. Major funding from @wellcometrust.bsky.social and @hhmijanelia.bsky.social. 2/10

Excited to share our new #biorxivpreprint:
“Sexual dimorphism in the complete connectome of the Drosophila male central nervous system” www.biorxiv.org/content/10.1...

We describe the #connectomics reconstruction and analysis of an entire adult #maleCNS #drosophila central nervous system. 1/10

WELCOME BACK! Join us for an aptly themed Let's Get Social Neurotalks next week to kick off the new year.

Social robots, and how flies use touch to make social decisions with Alva Markelius and @flofightscience.bsky.social

🗓️Tues 14 October
🕓7pm-9pm
🗺️ Cambridge Tap

Male CNS Connectome A team of researchers has unveiled the complete connectome of a male fruit fly central nervous system —a seamless map of all the neurons in the brain and nerve cord of a single male fruit fly and the ...

Exciting news for #drosophila #connectomics and #neuroscience enthusiasts: the Drosophila male central nervous system connectome is now live for exploration. Find out more at the landing page hosted by our Janelia FlyEM collaborators www.janelia.org/project-team....

🪰 A team of researchers has unveiled the complete connectome of a male fruit fly central nervous system—a seamless map of all the neurons in the brain and nerve cord of a single male fruit fly and the millions of connections between them.
🔗 https://hhmi.news/4o3EJnk

Male CNS Connectome A team of researchers has unveiled the complete connectome of a male fruit fly central nervous system —a seamless map of all the neurons in the brain and nerve cord of a single male fruit fly and the ...

We're very proud to be releasing the complete male fly CNS connectome!

It's the product of a huge team effort here at Janelia in partnership with the Cambridge Fly Connectomics group (@jefferis.bsky.social and colleagues), plus invaluable collaborators.

More soon...
www.janelia.org/project-team...

Save the Date
📍 Where: MRC-LMB, Cambridge or Online (Zoom)
🗓️ When: 10th and 11th of July
🧪 Themes: Cell Biology, Structural Biology, Immunology, Nucleic Acids and Neuroscience.
🤝 In collaboration with students at Institut Pasteur

The first paper from the lab is out on biorxiv - enjoy reading! Social context and interactions influence our behavioral decisions - the same is true for the little fly larva!

Our new paper on the circuit implementation of evidence integration in larval zebrafish is now on bioRxiv!

Correlative light and electron microscopy reveals the fine circuit structure underlying evidence accumulation in larval zebrafish https://www.biorxiv.org/content/10.1101/2025.03.14.643363v1

Such biophysically realistic network modeling provides the foundation for precise hypothesis-driven circuit manipulations, electrophysiology, and transcriptomic analysis in the future. So stay tuned😄(10/10)

Our anterior hindbrain circuit model, based on ground-truth connectivity, reproduces experimentally observed neural dynamics and predicts new mechanisms for flexible decision-making. (9/10)

Using 2P photo-activations and a ML classifier, we assigned functional labels to neurons based solely on morphology, enhancing our EM dataset. Our classifier also provides a basis to assign functional labels to other cell library resources for which calcium imaging had not been performed. (8/10)

After many months of intense tracing and synapse annotation, the result is a detailed connectome of functionally identified cells within the anterior hindbrain. (7/10)

We performed 2P calcium imaging to identify functional cell types related to this integration process. We then performed EM on the same preparation and mapped the two datasets together with cellular precision. Zetta AI has been instrumental in processing and segmenting the EM dataset. (6/10)

We use larval zebrafish, challenged with the classical random dot motion paradigm in which they need to accumulate motion evidence during sensory-motor decision-making. (image credit: Mariela Petkova) (5/10)

We are thankful to all the many many many other students and postdocs who helped with the experiments, imaging analysis, tracing, and database curation. (4/10)

The work has been a very productive collaboration between our lab, the Lichtman and Engert labs at Harvard University (connectomics), and the Baum lab at Zuse-Institut Berlin (Computer Science). (3/10)

In a heroic effort, the lead authors @boulangerweill.bsky.social and @flofightscience.bsky.social combined light and electron microscopy to address a long-standing question in neuroscience: What are the neural circuit mechanisms that allow animals to accumulate sensory evidence? (2/10)

Correlative light and electron microscopy reveals the fine circuit structure underlying evidence accumulation in larval zebrafish Accumulating information is a critical component of most circuit computations in the brain across species, yet its precise implementation at the synaptic level remains poorly understood. Dissecting su...

We are proud to present our new preprint “Correlative light and electron microscopy reveals the fine circuit structure underlying evidence accumulation in larval zebrafish”, just posted on bioRxiv (www.biorxiv.org/content/10.1...). (1/10)

The behavioral mechanisms governing collective motion in swarming locusts Collective motion, which is ubiquitous in nature, has traditionally been explained by “self-propelled particle” models from theoretical physics. Here we show, through field, lab, and virtual reality e...

Virtual reality rewrites the rules of the swarm. www.science.org/doi/10.1126/...
We find that classical models of collective behavior fail to account for collective motion.
www.science.org/doi/10.1126/...