skip to content

Department of Zoology

 

How are the resources supporting the supply of energy supply distributed across neural circuits? Inspired by interactions with Simon Lauglin in Cambridge Zoology early in my research career, my work explores this and other questions of how neural circuitry is organized to support behaviour. 

I use the visual system of flies: the circuitry is very regular, allowing repeated access to many cells; I can control visual stimuli with a precision difficult to achieve with other modalities; the power of Drosophila genetics and tools means we can access individual cell types to an extent not possible in vertebrates; finally, we have completely described the neuronal circuitry and the organization of neuronal mitochondria using connectomic analyses of EM data.

Previously, my work has identified neural mechanisms of visual processing and their modulation by internal states such as hunger and locomotion. It combines neurogenetics, behaviour, in vivo imaging of neural activity, electrophysiology, and connectomic analysis of neural circuits and their mitochondria. The long-term aim is to identify how neural circuits and their mitochondria coordinate and adapt to metabolic changes in health and disease.

I am currently also a visiting scientist with the Neural Circuits and Evolution Lab, Francis Crick Institute, London.

Biography

Reverse chronology:

  • Postdoc: Colour vision circuitry & behaviour, connectomic anlysis of visual circuitry and neuronal mitochondria in flies with Michael Reiser, HHMI Janelia, USA.
  • Conference lead organizer: "Colour Vision: Circuits and Behaviour", HHMI Janelia, 2019
  • Postdoc: Discovering how locomotion and nutrition modulate vision in flies with Holger Krapp, Zoology Cambridge then Imperial College London.
  • Lecturer, School of Informatics, University of Edinburgh
  • Marie Curie Fellowship with Alessandro Treves, SISSA, Italy
  • PhD Comnputational Neuroscience, supervised by David Willshaw, University of Edinburgh, modelling associative memory networks and the hippocampus.
  • Fellowship for PhD industrial placement, Tokyo, Japan
  • MSc Cognitive Science, University of Edinburgh
  • BSc Physics with Theoretical Physics, University of Manchester

Publications

Key publications: 

*First author contribution Equal contribution

  1. Nern, A., Lösche, F., Takemura, S.-Y., Burnett, L.E., Dreher, M., Gruntman, E., Hoeller, J., Huang, G.B., Januszewski, M., Klapoetke, N.C., Koskela, S., Longden, K.D, Lu, Z., Preibisch, S., Qiu, W., Rogers, E.M., Seenivasan, P., Zhao, A., et al. (2025). Connectome-driven neural inventory of a complete visual system. Nature 641, 1225-1237 doi.org/10.1038/s41586-025-08746-0
  2. Berg, S., Beckett, I.R., Costa, M., Schlegel, P., Januszewski, M., Marin, E.C., Nern, A., Preibisch, S., Wei Qiu, W., Takemura, S-.Y., Fragniere, A.M.C., et al. (2025). Sexual dimorphism in the complete connectome of the Drosophila male central nervous system. BioRxiv 2025.10. 09.680999 doi.org/10.1101/2025.10.09.680999
  3. Rivlin, P.K., Januszewski, M., *Longden, K.D., Neace, E., Scheffer, L.K., Ordish, C., Clements, J., Umayam, L., Yakal, E.A., Phillips, E., Walsh, C., Smith, N., Takemura, S., Plaza, S.M., Berg, S. (2024). Connectomic analysis of mitochondria in the central brain of Drosophila. BioRxiv 2024.04.21.590464v1 doi.org/10.1101/2024.04.21.590464
  4. Longden, K.D., Roger, E.M., Nern, A., Dionne, H., Reiser, M.B. (2023). Different spectral sensitivities of ON- and OFF-motion pathways enhance the detection of approaching color objects in Drosophila. Nature Communications 14, 7693. doi.org/10.1038/s41467-023-43566-8
  5. Longden, K.D., Schützenberger, A., Hardcastle, B.J., and Krapp, H.G. (2022). Impact of walking speed and motion adaptation on optokinetic nystagmus-like head movements in the blowfly Calliphora. Science Reports 12, 11540. doi.org/10.1038/s41598-022-15740-3
  6. Kind, E., *Longden, K.D., *Nern, A., *Zhao, A., Sancer, G., Flynn, M., Laughland, C., Gezahegn, B., Ludwig, H., Thomson, A., et al. (2021). Synaptic targets of photoreceptors specialized to detect color and skylight polarization in Drosophila. eLife 10, e71858. doi.org/10.7554/eLife.71858
  7. Longden, K.D., Wicklein, M., Hardcastle, B.J., Huston, S.J., and Krapp, H.G. (2017). Spike burst coding of translatory optic flow and depth from motion in the fly visual system. Current Biology 27, 3225-3236.e3. doi.org/10.1016/j.cub.2017.09.044
  8. Ding, Y., Berrocal, A., Morita, T., Longden, K.D., and Stern, D.L. (2016). Natural courtship song variation caused by an intronic retroelement in an ion channel gene. Nature 536, 329–332. doi.org/10.1038/nature19093
  9. Dyakova, O., Lee, Y.-J., Longden, K.D., Kiselev, V.G., and Nordström, K. (2015). A higher order visual neuron tuned to the spatial amplitude spectra of natural scenes. Nature Communications 6, 8522. doi.org/10.1038/ncomms9522
  10.  Longden, K.D., Muzzu, T., Cook, D.J., Schultz, S.R., and Krapp, H.G. (2014). Nutritional state modulates the neural processing of visual motion. Current Biology 24, 890–895. doi.org/10.1016/j.cub.2014.03.005