In Frechter et al eLife 2019 we made a major advance in our field by demonstrating that the lateral horn consists of a large population of stereotyped odour encoders. This confirmed a long-standing hypothesis. Many olfactory systems (including mice) show a bifurcation in the brain into higher order projections that likely support learned vs unlearned behaviour with stereotyped vs non-stereotyped responses. However, our results remain the only unambiguous evidence for this model.
The Drosophila "mushroom body" learning and memory centre has been the subject of intense investigation for almost 50 years. Dolan et al Neuron 2018 was a breakthrough since it produced the first specific circuit model for how learning can a) impact circuits in the rest of the fly brain to change behaviour and b) how learned behaviours can compete or suppress innate ones.
In Dolan et al Neuron 2018 we identified neurons required for innate attraction. Complementing this in Huoviala et al 2020 we found higher olfactory neurons required for innate aversive behaviour and followed the relevant pathways all the way from the sensory periphery to descending neurons projecting to the nerve cord. Once again this was a first. Once again, we found new convergence motifs downstream of the mushroom body. A second breakthrough was the demonstration that the labelled line encoding of valence in the olfactory periphery breaks down at the level of third order neurons.
Finally Galili et al 2022 demonstrated how and likely why flies can smell in stereo – enabling them to localise other flies in the dark. Stereo smell had been demonstrated in artificial scenario over 40 years ago, but no convincing explanation of how flies could do this in naturalistic settings was available until now. These and a range of other results demonstrated that processing of odours has much more similarity to visual or auditory processing than previously realised.
Many of these advances depend on new circuit mapping methods. We have had key roles in developing Drosophila connectome resources (Zheng et al Cell 2018, Scheffer et al eLife 2020) and sharing them eg through the virtualflybrain.org website of which I am a PI. We have developed novel computational tools in the R language (see natverse.org) and shared them via github or the public CRAN website (>45,000 downloads over the last 5 years).
Finally, we carried out many public dissemination activities. This ranged from local primary schools to the prestigious venue of the Royal Society, the UK's national academy. As the recipient of their Francis Crick medal, I delivered a lecture for ~500 members of the public in Jan 2020. The recorded lecture has been viewed 2700 times on youtube.
