Title

「How does expansion of olfactory sensory neuron population influence perception and behaviour?」 Postar🔗

Lecturer

Dr. Suguru Takagi

Date & Time

14:00~15:00, JULY 22nd (Mon.), 2024

Venue

Seminar Room B, Building G, Faculty of Medicine Campus

Abstract

Comparative neurobiology is a powerful approach to study the evolution of neural circuits and behaviour as well as to shed light on general principles of circuit function.
In this seminar, I will mainly talk about the functional impact of sensory neuron population expansion. The evolutionary expansion of sensory neuron populations detecting important environmental cues is widespread, but functionally enigmatic. We investigated this phenomenon through comparison of homologous olfactory pathways of Drosophila melanogaster and its close relative Drosophila sechellia, an extreme specialist for Morinda citrifolia noni fruit. D. sechellia has evolved species-specific expansions in select, noni-detecting olfactory sensory neuron (OSN) populations, through multigenic changes. Activation and inhibition of defined proportions of neurons demonstrate that OSN population increases contribute to stronger, more persistent, noni-odour tracking behaviour. These sensory neuron expansions result in increased synaptic connections with their projection neuron (PN) partners, which are conserved in number between species. Surprisingly, having more OSNs does not lead to greater odour-evoked PN sensitivity or reliability. Rather, pathways with increased sensory pooling exhibit reduced PN adaptation, likely through weakened lateral inhibition. Our work reveals an unexpected functional impact of sensory neuron expansions to explain ecologically-relevant, species-specific behaviour.

Contact

Laboratory of Cell Recognition and Pattern Formation、CeLiSIS
Yukako Hattori 075-753-9240