Dr Andrew Lin

We study how the brain represents sensory information to allow it to store unique memories, using the olfactory system of the fruit fly Drosophila melanogaster as a model system.

Olfactory sensory coding and memory

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.

Some methods we use:

• In vivo two-photon imaging
• Patch-clamp electrophysiology
• Individual-fly behavioural experiments
• Genetic manipulation of identified neurons
• Transcriptional profiling
• Computational modelling