Seemingly Redundant Modules Enhance Robust Odor Learning in Fruit Flies
HaiYang Li, Liao Yu, Qiang Yu, Yunliang Zang
Biological circuits have evolved to incorporate various modules that perform similar functions. In the fly olfactory circuit, both lateral inhibition and neuronal spike frequency adaptation are thought to enhance pattern separation for odor learning. However, it remains unclear whether these mechanisms serve redundant or distinct roles in odor learning. This study presents a model of the fly olfactory circuit to investigate odor identification under varying noisy conditions that simulate complex environments. Our results show that lateral inhibition enhances odor discrimination primarily in low-noise scenarios, while spike frequency adaptation becomes essential in noisier conditions. Both mechanisms lead to inconsistent changes in intra-class similarity and inter-class dissimilarity by shaping the representation of noisy odors. This work illustrates that seemingly redundant modules in biological circuits may be crucial for optimal learning in complex environments.