Olfactory coding from the periphery to higher brain centers in the Drosophila brain

Seki, Yôtâro; Dweck, Hany K.M.; Rybak, Jürgen; Wicher, Dieter; Sachse, Silke; Hansson, Bill S.

doi:10.1186/s12915-017-0389-z

Cited by 59 publications

(80 citation statements)

References 78 publications

(33 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Quantification of the evoked mean responses to specific odors showed that excitatory as well as inhibitory odor responses were, on average, stronger at the PN level than at the OSN level ( Fig. 7B) which is well in line with electrophysiological recordings (Wilson and Laurent, 2005;Bhandawat et al, 2007;Seki et al, 2017). To visualize how the odor-specific responses evolve over time, we applied principal component analyses to reduce the multidimensional, spatiotemporal activity/inhibition to three dimensions and illustrated the odor-evoked ensemble activity as trajectories over time (Fig.…”

Section: Input-output Transformationsupporting

confidence: 83%

Odor-Induced Multi-Level Inhibitory Maps inDrosophila

Grabe

Schubert

Strube-Bloss

et al. 2019

eNeuro

Self Cite

View full text Add to dashboard Cite

Optical imaging of intracellular Ca 2ϩ influx as a correlate of neuronal excitation represents a standard technique for visualizing spatiotemporal activity of neuronal networks. However, the information-processing properties of single neurons and neuronal circuits likewise involve inhibition of neuronal membrane potential. Here, we report spatially resolved optical imaging of odor-evoked inhibitory patterns in the olfactory circuitry of Drosophila using a genetically encoded fluorescent Clsensor. In combination with the excitatory component reflected by intracellular Ca 2ϩ dynamics, we present a comprehensive functional map of both odor-evoked neuronal activation and inhibition at different levels of olfactory processing. We demonstrate that odor-evoked inhibition carried by Clinflux is present both in sensory neurons and second-order projection neurons (PNs), and is characterized by stereotypic, odor-specific patterns. Cl --mediated inhibition features distinct dynamics in different neuronal populations. Our data support a dual role of inhibitory neurons in the olfactory system: global gain control across the neuronal circuitry and glomerulus-specific inhibition to enhance neuronal information processing.

show abstract

Section: Input-output Transformationsupporting

confidence: 83%

Odor-Induced Multi-Level Inhibitory Maps inDrosophila

Grabe

Schubert

Strube-Bloss

et al. 2019

eNeuro

Self Cite

View full text Add to dashboard Cite

show abstract

“…Compared to our prior findings in Pheidole [Ilieş et al, 2015], the results of our present study suggest that selection on brain organization differs in these formicine species (Table 1). The utility of our covariance analysis is validated by neuroanatomy: brain regions that were statistically correlated in the present work are known to have functional neural connections in insects [Strausfeld et al, 2009;Martin et al, 2011;Brill et al, 2015;Kinoshita and Homberg, 2017;Seki et al, 2017]. The correlations we identified between MB subregion size (LC and MC; MC and PL), for example, appear to reflect neurobiological organization, given that the LC and the MC receive similar primary sensory inputs, and the underlying afferent projections from the calyces form the PL [Fahrbach, 2006].…”

Section: Discussionmentioning

confidence: 90%

Social Complexity and Brain Evolution: Comparative Analysis of Modularity and Integration in Ant Brain Organization

2019

View full text Add to dashboard Cite

The behavioral demands of living in social groups have been linked to the evolution of brain size and structure, but how social organization shapes investment and connectivity within and among functionally specialized brain regions remains unclear. To understand the influence of sociality on brain evolution in ants, a premier clade of eusocial insects, we statistically analyzed patterns of brain region size covariation as a proxy for brain region connectivity. We investigated brain structure covariance in young and old workers of two formicine ants, the Australasian weaver ant Oecophylla smaragdina, a pinnacle of social complexity in insects, and its socially basic sister clade Formica subsericea. As previously identified in other ant species, we predicted that our analysis would recognize in both species an olfaction-related brain module underpinning social information processing in the brain, and a second neuroanatomical cluster involved in nonolfactory sensorimotor processes, thus reflecting conservation of compartmental connectivity. Furthermore, we hypothesized that covariance patterns would reflect divergence in social organization and life histories either within this species pair or compared to other ant species. Contrary to our predictions, our covariance analyses revealed a weakly defined visual, rather than olfactory, sensory processing cluster in both species. This pattern may be linked to the reliance on vision for worker behavioral performance outside of the nest and the correlated expansion of the optic lobes to meet navigational demands in both species. Additionally, we found that colony size and social organization, key measures of social complexity, were only weakly correlated with brain modularity in these formicine ants. Worker age also contributed to variance in brain organization, though in different ways in each species. These findings suggest that brain organization may be shaped by the divergent life histories of the two study species. We compare our findings with patterns of brain organization of other eusocial insects.

show abstract

“…The community PN axonal arbor territories s are similar to those obtained in earlier studies based on light microscopy data (c.f. cluster 1 in Figure 4 C&D Jefferis et al, 2007; Seki et al, 2017; c.f. green cluster in Figure 2 C,E Tanaka et al, 2004).…”

Section: Discussionmentioning

confidence: 98%

Structured sampling of olfactory input by the fly mushroom body

Zheng

Fisher

et al. 2020

Preprint

View full text Add to dashboard Cite

15Associative memory formation and recall in the adult fruit fly Drosophila melanogaster is 16 subserved by the mushroom body (MB). Upon arrival in the MB, sensory information undergoes 17 a profound transformation. Olfactory projection neurons (PNs), the main MB input, exhibit 18 broadly tuned, sustained, and stereotyped responses to odorants; in contrast, their postsynaptic 19 targets in the MB, the Kenyon cells (KCs), are nonstereotyped, narrowly tuned, and only briefly 20 responsive to odorants. Theory and experiment have suggested that this transformation is 21 implemented by random connectivity between KCs and PNs. However, this hypothesis has been 22 challenging to test, given the difficulty of mapping synaptic connections between large numbers 23 of neurons to achieve a unified view of neuronal network structure. Here we used a recent 24 whole-brain electron microscopy (EM) volume of the adult fruit fly to map large numbers of PN-25 to-KC connections at synaptic resolution. Comparison of the observed connectome to precisely 26 defined null models revealed unexpected network structure, in which a subset of food-responsive 27 PN types converge on individual downstream KCs more frequently than expected. The 28 connectivity bias is consistent with the neurogeometry: axons of the overconvergent PNs tend to 29 arborize near one another in the MB main calyx, making local KC dendrites more likely to 30 receive input from those types. Computational modeling of the observed PN-to-KC network 31showed that input from the overconvergent PN types is better discriminated than input from 32 other types. These results suggest an 'associative fovea' for olfaction, in that the MB is wired to 33 better discriminate more frequently occurring and ethologically relevant combinations of food-34 related odors. 35 36 45 (DasGupta et al., 2014; Dickinson and Muijres, 2016; Ofstad et al., 2011; Owald and Waddell, 46 2015); and the stereotyped morphology and physiology of its cell types allow ready integration 47 of information across individuals (Costa et al., 2016; Nern et al., 2015). Each cell type normally 48

show abstract

Olfactory coding from the periphery to higher brain centers in the Drosophila brain

Cited by 59 publications

References 78 publications

Odor-Induced Multi-Level Inhibitory Maps inDrosophila

Odor-Induced Multi-Level Inhibitory Maps inDrosophila

Social Complexity and Brain Evolution: Comparative Analysis of Modularity and Integration in Ant Brain Organization

Structured sampling of olfactory input by the fly mushroom body

Contact Info

Product

Resources

About