iiinova — where your digital self keeps evolving

Lex Kravitz @kravitzlab.com · 13/09/2026

How people are using AI can be so mystifying. How does this headline get through??

Lex Kravitz @kravitzlab.com · 30/07/2026

The work funded "in part" by Calocurb, a supplement company that makes a weight loss product using .... bitter hops extract. Not saying it doesn't work, but this isn't an independent test of it!

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Lex Kravitz @kravitzlab.com · 09/07/2026

Incredibly, mice with ablated VPGABA neurons (red line) completely failed to gain weight on high-fat diet. Normal control mice are in gray. By turning off over-eating outside of caloric need, we blocked obesity in mice.

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Lex Kravitz @kravitzlab.com · 09/07/2026

There's much more in the paper but I'll end this thread here - what if we remove VPGABA neurons? If animals don't eat outside of hunger, will they still gain weight if we challenge them with high-fat diets? We used a caspase approach to selectively ablate GABA neurons in the VP.

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Lex Kravitz @kravitzlab.com · 09/07/2026

Using a licking assay we found super reliable feeding from VPGABA stim - blue ticks are them drinking Boost chocolate drink whenever VPGABA cells are activated!

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Lex Kravitz @kravitzlab.com · 09/07/2026

With transcriptomic analyses and fiber photometry we determined that VPGABA neurons, despite driving feeding, do not sense the hunger hormone ghrelin. So we have a neural population that doesn't sense hunger, but can drive feeding.... it can literally drive feeding independent of caloric need

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Lex Kravitz @kravitzlab.com · 09/07/2026

We compared optogenetic stimulation of the classic "homeostatic" arcuate AGRP neuron population to GABA neurons in the ventral pallidum, finding that both drove feeding, but VPGABA stimulation only drove feeding for palatable high-fat diet

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Lex Kravitz @kravitzlab.com · 09/07/2026

What are hedonic vs homeostatic feeding? The homeostatic appetite describes the drive to consume food to meet energy needs, whereas the hedonic appetite refers to feeding outside of energy needs, which is frequently directed toward palatable foods.

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Lex Kravitz @kravitzlab.com · 14/12/2025

This statement gave me a hall of mirrors feeling.

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Lex Kravitz @kravitzlab.com · 25/09/2025

Just got home from a trip and received this book by @juliabelluz.bsky.social and @kevinh-phd.bsky.social!

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Lex Kravitz @kravitzlab.com · 02/05/2025

I found Jimmy Carter's Environmental Program (fittingly?) in the dumpster in the alley behind my house. "The sight of earthrise was awesome. It was also sobering. From that moment we could no longer avoid understanding that all life must share this one small planet and its limited resources."

Pamphlet of the President's Environmental Program 1979

Quote from Jimmy Carter: "Ten years ago, at the dawn of the environmental decade, we landed on the moon. For the first time people could stand on the surface of another world and look at the whole earth. The sight of earthrise was awesome. It was also sobering. From that moment we could no longer avoid understanding that all life must share this one small planet and its limited resources."

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Lex Kravitz @kravitzlab.com · 26/04/2025

It's funny that ChatGPT does this shit too

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Lex Kravitz @kravitzlab.com · 04/01/2025

I thought of your posts today when trying to look up a fairly simple fact on Google.

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Lex Kravitz @kravitzlab.com · 28/12/2024

Working on a new gaming system for mice over the holidays

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Lex Kravitz @kravitzlab.com · 06/12/2024

I took this photo of Jupiter + moons from inside my house in St Louis, aiming the telescope at the bright spot in the sky and using my phone pointed down the eyepiece to capture it. Technology is amazing, this is not a fancy scope. I turned the lights off in the room but otherwise here's the setup!

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Lex Kravitz @kravitzlab.com · 02/12/2024

Congrats to Dr. Alex Legaria, the first PhD student to graduate from my lab! Lots of feelings as his PI, but mostly I'm grateful that I didn't eff it up 😄😅😁

Alex Legaria speaking at his PhD defense

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Lex Kravitz @kravitzlab.com · 23/11/2024

The elusive D1/D2 co-expressor!

Zoomed in image of striatum showing a cell that coexpresses d1 and d2

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Lex Kravitz @kravitzlab.com · 25/10/2024

In this way, we held the nutritional content and diet composition constant, while very lightly manipulating how hard it was to obtain. Mice gained weight when the diet was free (Blue bars), but not when they had to nose-poke *just one time* (Red bars, FR1)!

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Lex Kravitz @kravitzlab.com · 08/10/2023

We were inspired by a recent paper (www.sciencedirect.com/science/arti...) to perform a crowd sourced analysis of rodent in-cage housing temperature across 12 different colonies. We analyzed 220,000 temperature measurements and found a ~4°C range among the different colonies.

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