Abstract
BackgroundOdor information is processed through multiple receptor-glomerular channels in the first order olfactory center, the antennal lobe (AL), then reformatted into higher brain centers and eventually perceived by the fly. To reveal the logic of olfaction, it is fundamental to map odor representations from the glomerular channels into higher brain centers.ResultsWe characterize odor response profiles of AL projection neurons (PNs) originating from 31 glomeruli using whole cell patch-clamp recordings in Drosophila melanogaster. We reveal that odor representation from olfactory sensory neurons to PNs is generally conserved, while transformation of odor tuning curves is glomerulus-dependent. Reconstructions of PNs reveal that attractive and aversive odors are represented in different clusters of glomeruli in the AL. These separate representations are preserved into higher brain centers, where attractive and aversive odors are segregated into two regions in the lateral horn and partly separated in the mushroom body calyx.ConclusionsOur study reveals spatial representation of odor valence coding from the AL to higher brain centers. These results provide a global picture of the olfactory circuit design underlying innate odor-guided behavior.
Highlights
Odor information is processed through multiple receptor-glomerular channels in the first order olfactory center, the antennal lobe (AL), reformatted into higher brain centers and eventually perceived by the fly
A total of 67 out of the recorded 71 Projection neuron (PN) represent uniglomerular PNs that extended their primary dendrites into a single glomerulus and sent their axons to the calyx of the mushroom body (MB) and the lateral horn (LH) through the medial antennal lobe tract known as the inner antenno-cerebral tract (IACT) (Fig. 1a)
We focused our analyses on the 67 uniglomerular PNs innervating one out of 31 glomeruli and covering ~60% of 52 olfactory glomeruli present in the Drosophila AL
Summary
Odor information is processed through multiple receptor-glomerular channels in the first order olfactory center, the antennal lobe (AL), reformatted into higher brain centers and eventually perceived by the fly. Several studies analyzing the anatomical map of axonal projections of PNs in the MB calyx and the LH have shown less deterministic wiring patterns in the MB calyx and highly stereotyped projection patterns in the LH [11, 13, 16, 17]. This supports the view that the MB is involved in plastic processes such as learning and memory, while the LH is directly linked to innate behaviors [13, 18,19,20,21,22]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
