Mating-driven variability in olfactory local interneuron wiring

Abstract

Variations in neuronal connectivity occur widely in nervous systems from invertebrates to mammals. Yet, it is unclear how neuronal variability originates, to what extent and at what time scales it exists, and what functional consequences it might carry. To assess inter- and intraindividual neuronal variability, it would be ideal to analyze the same identified neuron across different brain hemispheres and individuals. Here, using genetic labeling and electron microscopy connectomics, we show that an identified inhibitory olfactory local interneuron, TC-LN, exhibits extraordinary variability in its glomerular innervation patterns. Moreover, TC-LN’s innervation of the VL2a glomerulus, which processes food signals and modulates mating behavior, is sexually dimorphic, is influenced by female’s courtship experience, and correlates with food intake in mated females. Mating also affects output connectivity of TC-LN to specific local interneurons. We propose that mating-associated variability of TC-LNs regulates how food odor is interpreted by an inhibitory network to modulate feeding.

Nonspiking Interneurons in theDrosophilaAntennal Lobe Exhibit Spatially Restricted Activity

“…Additionally, previous work has shown unique roles for subpopulations of LNs (Chou et al, 2022;Huang et al, 2010;Liu and Wilson, 2013;Sizemore et al, 2022;Suzuki et al, 2020).…”

“…Physiologic characterization of LNs has revealed distinctions ( Chou et al, 2010 ; Seki et al, 2010 ) and some classes of these LNs have been probed for morphology. Additionally, previous work has shown unique roles for subpopulations of LNs ( Huang et al, 2010 ; W.W. Liu and Wilson, 2013 ; Suzuki et al, 2020 ; Chou et al, 2022 ; Sizemore et al, 2022 ). However, correlating LN physiology with morphology remains difficult.…”

Connectomics and the neural basis of behaviour

“…On the other, the truncated and large number of new EM morphologies, the difficulty in assigning cell types and the lack of comprehensive inter-and intra-individual comparisons for both sexes. Common to both is the experience-dependent or -independent morphological and connectivity variability [17,32,78]. This process of mapping cell types also leads to the identification of driver lines [28,29] that can be used for behavioural assays and the increase in the availability of sparsely labelled lines [79] is facilitating this process.…”

Flexibility of neural circuits regulating mating behaviors in mice and flies

“…10.3389/fncir. 2022.949781 Strikingly, a recent study revealed that mating experience also modulates the wiring of olfactory neurons in the female brain (Chou et al, 2022). A set of inhibitory olfactory local neurons ("TC-LN") exhibit specific and significantly increased innervation of the VL2a glomerulus, possibly contributing to feeding behaviors in post-mated females.…”