Thank you so much, Flora!! Some of the CaMKII results are thanks to the early advice you gave me about ordering drugs from MedChemExpress :)

Sorry I just realized that bluesky inverted the coloring of the graphs after I uploaded them! You'll have to read the paper to see the real graphs :)

Molecular pathways for learning in the single-cell Stentor coeruleus Rajan et al. explore the molecular basis of habituation in the unicellular organism Stentor coeruleus using a combination of pharmacological methods, proteomics, transcriptomics, and RNAi. These exper...

Link to paper in @CurrentBiology. Thank you to co-authors @aralbright.bsky.social @gautamdey.bsky.social and more. @ucsfhealth.bsky.social @ucsfmedicine.bsky.social @uofcalifornia.bsky.social
www.cell.com/current-biol...

There is still much left to learn – for both Stentors and the humans who study them! Which other molecules drive Stentor habituation? What else can they learn? By researching how a single cell learns, we can begin to shed light on the origins of intelligence. 13/n

Indeed, the habituated state can be propagated to daughter cells during cell division! 12/n

But is this habituation memory localized? Can it persist in progeny? To test this, we trained cells with mechanical taps as they were dividing. The video below is sped up over 7 hours of training/dividing. 11/n

These findings are consistent with a receptor-inactivation mechanism for Stentor habituation: mechanoreceptor senses stimulus ➡️ channel opening changes membrane potential ➡️ CaMKII activation ➡️ protein phosphatase activation ➡️ dephosphorylation of mechanoreceptors. 10/n

We also knocked down SteCoe_6763, another calcium-binding RNA-seq candidate, using RNA interference and found that knocking down this protein accelerates habituation. We’re thinking of calling this protein “ignoramin” because getting rid of it improves learning! 9/n

Calcium/calmodulin-dependent kinase II (CaMKII), one of the RNA-seq candidates, is essential for learning in animals. We found that KN-93, a drug that inhibits CaMKII, impairs habituation in Stentor cells. 8/n

This suggests that forgetting is an active process that requires new protein synthesis. But which molecules are being synthesized/degraded? We did a series of RNA-seq and proteomics experiments to obtain molecular snapshots of cells during learning and forgetting. 7/n

For decades, the prevailing story has been that we (multicellular animals) need to make new proteins to learn. Surprisingly, habituation in Stentor cells improves after treatment with drugs like puromycin that impair protein synthesis! 6/n

When Stentors receive repeated weak mechanical stimulation, however, they habituate and thus stop contracting and remain in their elongated state. Below is a video of Stentors that have become habituated after an hour of repeated stimulation. 5/n

When Stentors experience a mechanical stimulus, they contract into a ball-like shape – presumably to escape from predators lurking in the pond. 4/n

Habituation is the gradual decrease in response after repeated stimulation. Humans do this, too! For example, we learn to ignore the feeling of clothes on our skin after wearing them all day. However, we have 86 billion neurons to help us learn while Stentor is a single cell! 3/n

If you scoop up some water from a local pond and stick it under a microscope, you might just encounter Stentor coeruleus, a unicellular organism that is capable of a type of learning called habituation. 2/n

How can a single cell learn without a brain? We explore this in my paper with @wallaceucsf.bsky.social! We discovered that single cells may learn using molecules similar to those that animal brains use to learn, like CaMKII. Cells can also propagate memory states to their progeny!

www.nature.com/articles/s41...

We discovered a new species! Our paper on Stentor stipatus is now published @wallaceucsf.bsky.social @aralbright.bsky.social

A drawing in sepia tones of a child looking at the reader. In the upper left corner are the logos for The B'K and Global Majority Press. Text says Volume 17, Issue 2, and has the list of creatives. Text says Launching April 1.

Just a few more days until we launch The B'K Volume 17, Issue 2 featuring poetry by: Ashen Speir, Cypher, David Anson Lee, @deeparajan.bsky.social, Jamez Terry, Joni Thomas, Kieran Fu, Leslie Dianne, Maxochitl Cortez, Muheez Olawale, and Theodora Bonis. Stay tuned!

Lectures on Tap - Learning Without a Brain: How Intelligence Begins Small Professors, experts, and storytellers giving thought-provoking lectures in SF bars.

link to tickets! www.eventbrite.com/e/lectures-o...

If you're in SF, come celebrate St. Patrick's day with me and learn about how single cells learn! I'm giving a lecture about my research at a bar as part of the Lectures on Tap series🍻

dissertation book haul!

Trump minimizes domestic abuse during a talk at the Museum of the Bible: "Things that take place in the home, they call crime ... If a man has a little fight with the wife, they say this was a crime, see?"

Help us record firefly flashes! 👇🙏

Our research on wound resistance in Stentor is live on bioRxiv! Tldr; we squeezed the cells through microfluidic constrictions and the formidable lead author Rajorshi Paul characterized what makes the cells get wounded!

thank you!!

Our paper on single-cell learning is now published in
@currentbiology.bsky.social!
@wallaceucsf.bsky.social

sciencedirect.com/science/arti...

Stentor in Every School: t.co/2AalQ8y91l

I'm leading a program at the Exploratorium @exploratorium.bsky.social this weekend! Come check out "Mini Microbe Missions", an opportunity for kids (and adults) to do citizen science using the single cell Stentor coeruleus, supported by our Stentor in Every School initiative t.co/VX8r9BHxsJ

Went to a wonderful reunion for the birthday of dear friend and colleague Gerd Blobel yesterday. In the end, it’s funny how all the papers and grants fade away and the main thing you remember are the people.