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KL Nikhil

@circatwenty4.bsky.social
89 followers 120 following 19 posts

Exploring how our bodies tell time | McDonnell Fellow | Humboldt Fellow | INSA Young Scientist Medal | Herzog Lab | JNCASR 🇮🇳 - Charité 🇩🇪 - WashU 🇺🇸 | klnikhil.wordpress.com

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Reposted by KL Nikhil
Erik Herzog @erikherzog.bsky.social · 10/04/2026
Babies synchronize their daily rhythms to mom before birth! Work by @circatwenty4.bsky.social and colleagues. source.washu.edu/2026/04/when...
source.washu.edu
When does the body clock begin to synchronize with local time?
New research from Washington University in St. Louis shows that a mother helps to set the biological clock for her babies while they are still in the womb.
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KL Nikhil @circatwenty4.bsky.social · 14/04/2026
Our work on #circadian clocks during #pregnancy is now out. We developed a way to track daily rhythms in the developing fetus and show that mother's clock helps the baby synchronize to local time even before birth!
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KL Nikhil @circatwenty4.bsky.social · 19/01/2026
Check out the summary of our recent work on mapping brain communication.
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Reposted by KL Nikhil
PessoaBrain @pessoabrain.bsky.social · 20/12/2025
*The architecture of living systems* Ambitious treatment of the physics of living systems Some quibbles but impressive! iopscience.iop.org/article/10.1... #complexsystems
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Reposted by KL Nikhil
Erik Herzog @erikherzog.bsky.social · 12/12/2025
Congrats KL Nikhil and collaborators on inventing MITE to map functional brain connections! Surprising take home: MITE reveals 5 cell types (based on their connectivity) in the mouse circadian clock which underlie the daily wave of gene expression. www.pnas.org/doi/10.1073/...
pnas.org
The inferred functional connectome underlying circadian synchronization in the mouse suprachiasmatic nucleus | PNAS
Circadian rhythms in mammals arise from the spatiotemporal synchronization of ~20,000 neuronal clocks in the suprachiasmatic nucleus (SCN). Althoug...
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KL Nikhil @circatwenty4.bsky.social · 27/04/2025
Excited to be a part of this work with Bharat Singhal! Is your data good enough to reveal true cell-cell connectivity? We developed a statistical method to find out — tested on simulations and real-world #networks. shorturl.at/I3KfB #NetworkScience #ComplexSystems #IEEEXplore
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Reposted by KL Nikhil
Richard Sever @richardsever.bsky.social · 11/03/2025
Big news: we are setting up a new non-profit organization to run bioRxiv and medRxiv. It's called openRxiv [no it's not a new preprint server; it's dedicated organization to oversee the servers] openrxiv.org 1/n
openrxiv.org
Homepage - openRxiv
openRxiv is an independent non-profit, the new organizational home for bioRxiv and medRxiv, enabling researchers to instantly share groundbreaking findings with the global scientific community.
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KL Nikhil @circatwenty4.bsky.social · 05/03/2025
www.sciencedirect.com/science/arti...
sciencedirect.com
Should biology put complexity first?
The dictum “Everything should be made as simple as possible, but no simpler” poses a problem for biology. How simply can it be told without doing dama…
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KL Nikhil @circatwenty4.bsky.social · 31/12/2024
I've developed a python program for circadian analysis at pixel resolution in tissue recordings. Happy to share it. We have used it in this work - www.pnas.org/doi/10.1073/...
pnas.org
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KL Nikhil @circatwenty4.bsky.social · 31/12/2024
I've had this discussion with Lance Riley :) It is a very interesting system! If you can extract time series/pixel intensities from each nucleus, inter-nucleus communication can be mapped with this method.
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
In conclusion, we reveal that robust circadian timekeeping in mammalian SCN arises from functionally heterogeneous cell types, organized into two cellular networks and driven by a subset of VIP hubs neurons with unique connectivity topology. end!
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
Network wiring shapes SCN emergent properties: Simulated SCN cell behavior showed a strong correlation with their corresponding experimentally recorded explants. In silico ventral SCN synchronized faster and also recapitulated the characteristic wave of PER2 expression. (12/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
All signals converged on the dorsal 'sink' cells (including the AVP cells) which were not essential for driving SCN synchrony. We also identified 'bridge' cells in the central SCN that couple information flow across the modules & likely underlie seasonal SCN reorganization (11/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
VIP hubs drive SCN circadian synchrony: We found a topologically unique group of VIP hub neurons that generate and broadcast signals with their extensive and long-range connections. SCN networks did not synchronize on ablating the VIP hubs but not AVP cells. (10/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
To identify key hub cells driving SCN network synchrony, we simulated the experimentally inferred SCN maps in 6 mice and tested the impact of ablating various cell types on networks' ability to synchronize. (9/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
We identified four functional cell types that mediate circadian signaling across the SCN neural network, acting as circadian signal 'generators,' 'broadcasters,' 'bridges,' or 'sinks.' (8/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
The SCN exhibited strong ventral-to-dorsal signaling, with over 60% of all connections originating from ventral cells. Accordingly, ventral module cells synchronize their rhythms first, driving the rest of the network. (7/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
Two asymmetrically coupled cellular networks drive SCN synchrony: Within each explant, we found dorsal and ventral cellular modules resembling the anatomical shell-core regions. Notably, these were absent in explants that failed to synchronize during our experiments. (6/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
While SCN cells connect as a #smallworld network with most cells signaling proximally; intriguingly, we found a few long-range connections from ventral cells that project halfway > across the SCN, short-circuiting the network to enhance signal transmission. (5/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
Mammalian clock is efficiently wired: SCN connectivity patterns were highly conserved, both bilaterally and across mice. SCN is sparsely connected compared to other brain areas (~720 connections/cell), yet signals reached any other SCN cell via just 3–4 intermediaries! (4/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
We developed an #informationtheory method, MITE, to identify functional cell-cell connections by observing the coevolution of circadian gene expression as the cells synchronized. This framework can be used for inferring connectivity in any cellular network. (3/n)
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
Preprint: www.biorxiv.org/content/10.1... (2/n)
biorxiv.org
The Functional Connectome Mediating Circadian Synchrony in the Suprachiasmatic Nucleus
Circadian rhythms in mammals arise from the spatiotemporal synchronization of ∼20,000 neuronal clocks in the Suprachiasmatic Nucleus (SCN). While anatomical, molecular, and genetic approaches have rev...
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KL Nikhil @circatwenty4.bsky.social · 30/12/2024
Excited to share my new #preprint with @erikherzog.bsky.social! By mapping the functional #connectome of the #SCN using 3000+ hours of recordings from 9000+ cells in 17 mice, we explored how mammalian clock neurons synchronize to produce #circadian rhythms. (1/n)
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