Periodic Reporting for period 3 - EnergyMemo (Dynamic Interplay between Energy and Memory)
Reporting period: 2020-10-01 to 2022-03-31
Using Drosophila for our studies gives access to a plethora of versatile genetically expressed tools to manipulate energy metabolism pathways in the course of memory formation, but also to monitor the use of energy by neurons and their neighbouring glial cells through fluorescence imaging experiments. In addition, previous work for our lab and others in the field provided a precise description of the neural networks involved in the encoding of memories over different time scales in the fly’s brain.
With this in hand, we developed research thematics at the interface of learning and memory and energy metabolism fields, which gives our team an original positioning within the international research landscape. Our objectives are to highlight timely regulations of energy supply to neurons is key to proper encoding of long-term memory, and to identify the network and molecular mechanisms that underlie those regulations, with a particular emphasis on neuron-glia interaction.
In parallel, we initiated our studies of neuron-glia interaction during long-term memory. We showed that a particular type of glial cells, that enwraps the neuronal cell bodies, is activated during memory formation, and we delineated the full molecular mechanism of the neuron-to-glia and glia-to-neuron metabolic dialogue (de Tredern et al., in preparation).
Finally, developing a pionneer expertise in the fluorescent imaging of energy metabolism fostered collaboration with the group of Irene Miguel-Aliaga, on a project focused on inter-organ communication in Drosophila. Using fluorescent sensors that we provided, this group showed that carbohydrate metabolism in the intestine is sexually dimorphic and that gut-derived citrate promotes food intake and sperm production (Hudry et al., Cell (2019)).
While our studies have been mostly focused on long-term memory so far, which is the most stable memory phase described in Drosophila, we expect in the remaining part of the project to also address the putative metabolic regulations that engage mushroom body neurons into the formation of other, less stable memory phases. We will also investigate the state-dependent alteration of memory ability under the angle of the modifications of neuron-glia interaction. At the end of the project we expect to get a comprehensive picture of metabolic plasticity occuring in the mushroom body, from learning to long-term memory formation.