@flypapers

Quite the proposal that upturns a long unquestioned mechanism of associative memory: “cAMP level is an unlikely candidate for serving as a memory engram. Furthermore, our findings demonstrate that cAMP has an adverse impact on the release of acetylcholine from KCs. Accordingly, we postulate that, during conditioning, cAMP depresses KCs, thereby skewing the valence of the CS+ odor towards a more aversive state for the conditioned flies, ultimately culminating in the formation of aversive memories.”

#Drosophila #LearningAndMemory #MushroomBody

"Flexible specificity of memory in Drosophila depends on a comparison between choices", by Modi et al. 2023 (Glenn Turner's lab) https://elifesciences.org/articles/80923

"A memory too specific will be useless in even a slightly different environment, while an overly general memory may lead to suboptimal choices."

"Rather than forming memories that strike a balance between specificity and generality, Drosophila can flexibly categorize a given stimulus into different groups depending on the options available."

#neuroscience #LearningAndMemory #MushroomBody #Drosophila

"Hacking brain development to test models of sensory coding"
Ahmed et al. 2023 (Clowney lab)

"we develop methods to increase and decrease Kenyon cell claw number and therefore the number of olfactory inputs that individual Kenyon cells receive."

(claws are the inputs from projection neurons (PNs), and Kenyon cells are like granular cells in the cerebellum.)

"We then use these circuit-hacked animals to test the effects of altering Kenyon cell number and claw number on sensory representations and associative learning behavior. We find that changing Kenyon cell number only modestly affects population-level odor responses. In contrast, Kenyon cell odor responses change bidirectionally as we change Kenyon cell dendritic claw number, such that Kenyon cells become less odor-selective as their input number grows."

"Remarkably, animals with reduced Kenyon cell population size can learn simple olfactory associations, and animals with augmented sets of Kenyon cells show improved associative learning."

#Drosophila #neuroscience #KenyonCells #MushroomBody

@scottishwaddell

Wow Scott—the abstract alone is like a mini neuroscience conference on learning and memory. Looking forward to reading it slowly.

Meanwhile: could you tell us about the voltage imaging? Any caveats?

#Drosophila #neuroscience #LearningAndMemory #MushroomBody #KenyonCells #engran #MultisensoryIntegration