Thread by @Hardkandy000

Our paper is out, by @NGPMichigan1 @cemay7 and @UMich_MCDB @anoumid: cell.com/cell-reports/f…

- A high sugar diet decreases sweet taste
- Blunted taste promotes eating
- Preventing taste deficits protects animals from obesity
- How? Sugar metabolism inside the taste cells

The Dus lab studies the effects of environment on behavior, and specifically the food environment. We know that around foods with sugar, salt, and fat animals overeat, but how does it happen?

Recent studies found that taste responses may be blunted in humans and rodents with obesity, but are these changes bc of diet or obesity? What role do they play in feeding behavior? Are they a consequence or a driver of obesity?

We found that fruit flies on a high sugar diet had increased feeding: longer and bigger meals. They also had lower behavioral and physiological responses to sweet stimuli, so their ability to taste sweet was dulled.

We used opto- and neurogenetics to correct or prevent sweet taste deficits, and !!! the animals were protected from diet-induced obesity! They stayed lean even on a high sugar diet (candy dinner)! Thus changes in taste sensation DRIVE more eating and obesity.

So how does sweet taste get blunted? We used genetically-obese and lean flies, along with dietary manipulations that preserved caloric intake or sweetness. We found that it is dietary sugar, not obesity, sweetness or extra calories alone, that decreases sweet taste.

How? The sweet taste cells keep track of how much “sugar” is on the inside using a metabolic signaling pathway that senses sugar. People have studied this pathway in the body, but only recently in the brain.

We KD the main enzyme OGT in the taste cells, this restored taste, responses, feeding, and kept animals lean. Thus, this is cell- autonomous: sweet taste cells can sense sugar from both the “outside” and the “inside.” This is cool!

This was the work of PhD students @cemay7 and @avaziri. Thank you also to @Neely_Lab for the sensilla recording, Freddolino lab for modeling gene expression, and Pletcher lab for collaborating on the CLOSED LOOP OPTOFLIC. @cemay7 will be on the job market soon!

SO MANY NEW QUESTIONS! How do changes in taste promote eating? What is the connection between taste changes and reward? And how do these affect learning and predictions about food? @cemay7 and @ThibautPardo are now studying this!

@cemay7 @ThibautPardo And how does sugar metabolism decrease the activity of the sweet taste cells? Is this deficit reversible? What are the connections between metabolism, gene expression and neural function? @anoumid is working on this!

@cemay7 @ThibautPardo @anoumid The illustrations in the paper are by Julian Kuhl @mulesome, she is an amazing artist, her #sciart blessed many covers and papers :D