The Effect of Circuit Structure on Odour Representation in the Antennal Lobe - Mushroom Body Circuit

Abstract

Understanding how the structure of neural circuits mediates its function is an area of key interest in neuroscience, particularly in instances where circuits that are trying to accomplish the same over-arching goal, make use of different structural parameters. The antennal lobe - mushroom body circuit of the insect olfactory system - that functions to represent odours experienced by the insect - is one of the most well characterized neural circuits, with physiology and function having been studied in great detail up to the 4th order neurons. In addition there exists significant variations in the structural parameters of this circuit between insects. It therefore provides a useful model in which to understand structure-function relationships. In this thesis I will begin by studying the effect of including temporal structure in neural activity on the function of this circuit. My results suggest that this temporal structure is utilized differently by the circuit depending on the structural parameter regimes adopted, allowing different parameter regimes to function optimally in different conditions. Such results are not predicted by the more simplistic models used in earlier studies, implying that more realistic models of neural circuitry can provide novel insight into its function. I will then show more rigorously that there is more than one regime of structural parameters in which this circuit can perform its function optimally.