Andrew Lin received his bachelor’s degree in biology summa cum laude from Harvard University in 2004. He did his Ph.D. with Christine Holt at the University of Cambridge, where he studied the regulation of local protein synthesis in axonal growth cones, funded by a Gates Cambridge Scholarship and a National Science Foundation Graduate Research Fellowship. For his postdoctoral work he moved to studying olfactory sensory coding and associative memory in the fruit fly Drosophila, with Gero Miesenböck at the University of Oxford, funded by a Sir Henry Wellcome Postdoctoral Fellowship. Andrew is now a Vice-Chancellor’s Fellow at the University of Sheffield, where he started his research group in 2015, funded by a Starting Grant from the European Research Council. His lab studies how the brain sets up and maintains the correct circuit parameters to function optimally, using the Drosophila olfactory system as a model.

How does the brain recognise sensory stimuli? How does it form distinct memories for different stimuli, even very similar ones? And how does it wire itself up to process information in the best way to achieve these remarkable feats? Our research addresses these fundamental questions using the olfactory system of the fruit fly Drosophila melanogaster. Flies have a much simpler nervous system than humans but are still capable of complex behaviours such as associative memory. This simplicity, combined with the power of fly genetics, makes Drosophila an excellent model system for tackling basic questions about neural circuit function.

Flies can form distinct associative memories for different odours, even very similar ones, and this stimulus-specificity depends on ‘sparse coding’, in which Kenyon cells, the neurons that encode olfactory associative memories, respond sparsely to odours, i.e. only a few neurons in the population respond to each odour. This sparse coding in turn depends on a delicate balance of excitation and inhibition onto Kenyon cells. We are studying how this balance is created and maintained. By improving our understanding of how the brain balances excitation and inhibition, this work may shed light on neurological disorders, like epilepsy, where this balance goes wrong.