The connectome of olfactory memory circuits in the adult fly

The brain is an interconnected network of specialised, electrically active cells called neurons. Storing and retrieving memories is vital to the brain’s control of behaviour and therefore the subject of intense study. Although the connections between neurons are known to be critical for brain function, the detailed set of connections required for memory storage and retrieval remain unknown. A new area of neuroscience, connectomics, aims to describe the complete set of connections in large brain areas. Neuronal connections are tiny and are measured in nanometres and can only be resolved using electron microscopy to reveal structures smaller than 1/10,000 of a hair’s width. Imaging a whole brain at this resolution is technically challenging, but this has now been done for the fruit fly, a key model for understanding mechanisms of learning and memory.

In this project, teams from Cambridge, Oxford and the US will: produce a freely available connection atlas (connectome) of a memory centre; develop the necessary computer technology and organisational strategies;and show that this connectome helps us better understand the brain.

Reconstructing a small vertebrate brain will be a huge undertaking, but future projects will build on the foundations laid here.