Project Details
Projekt
Mechanisms for robust odour coding based on variable circuit architectures
Applicant
Carlotta Martelli, Ph.D.
Subject Area
Molecular Biology and Physiology of Neurons and Glial Cells
Developmental Neurobiology
Developmental Neurobiology
Term
since 2022
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 453877723
The environment shapes animal development in multiple ways. A prominent example is the effect of temperature on the developmental rate of poikilothermic animals, that do not control body temperature. Based on groundwork by the RobustCircuit consortium, a core outcome of our work from the first funding period has revealed a quantitative explanation of how slower development at lower temperatures results in increased brain connectivity in Drosophila. The observation of different circuit architectures leads to the question of whether brain function is robust to development at different temperatures. Focusing on the olfactory system, we have shown that odour representations are robust to changes in connectivity caused by a certain temperature range. Following these discoveries, we now ask to what extent this functional robustness holds across a range of stimuli and developmental conditions and which wiring principles support it. Odours are encoded in the population activity of olfactory Projection Neurons (PNs) that receive direct excitatory inputs from Olfactory Receptor Neurons (ORNs) and are modulated by recurrent inhibition from Local Neurons (LNs). Our first goal will be to characterize the domain of robustness of odour encoding in PNs by using a large set of odours and temperature manipulations. We expect that odour representations will differ at extreme temperatures when the circuit connectivity is highly disturbed, but that they will be robust in a large range of conditions of ecological relevance. Our second goal will therefore be to identify which principles of circuit wiring are implemented in the olfactory system such that odour coding does not require precise wiring and remains robust across a range of environmental perturbations. For this, we will conduct a detailed anatomical analysis of synapse numbers, distribution and organization to understand the effect of temperature on different types of synaptic partners. Finally, we will use pharmacological and genetic approaches to interfere with circuit connectivity and test whether the balance between feedforward excitation and local inhibition supports temperature invariant odour coding. When these studies are concluded, we will have described key principles of robust function based on variable circuit architectures using a framework that is highly ecologically relevant (temperature) and has the potential to reveal regimes where developmental plasticity supports phenotypic adaptation.
DFG Programme
Research Units
