Senior Author

Fish oil has a reputation as ‘brain food’, but whether this is justified and, if so, how the oil works, is unclear. Working with his colleague Frédéric Darios, Bazbek Davletov at the MRC Laboratory of Molecular Biology in Cambridge, UK, was studying protein–protein interactions involved in neuronal growth. The pair thought that omega-3 and omega-6 fatty acids might be involved in the process. They found that one protein, syntaxin 3, was necessary for cell-membrane growth and that the omega fatty acids stimulate this protein. Davletov spoke to Nature about their results, which appear on page 813.

Why look at membrane growth?

The cell membrane defines the boundary of a single unit of life: the cell. For cells to grow, for example during axonal growth in the brain, the membrane must expand.

And why omega-6 and omega-3?

Omega-6 and omega-3 fatty acids were implicated in the growth of neuronal membranes during brain development, but no one knew why these acids were specifically important for neuronal growth.

Any surprises?

We were astonished to find that syntaxin can engage its protein partners only in the presence of omega-3 and omega-6 fatty acids. So we should not overlook the importance of signalling pathways in regulating protein–protein interactions. For example, many protein-interaction networks are currently built without taking into account small metabolic molecules, which are dynamically regulated inside the cell. I think we will achieve a fuller knowledge of the cell when we merge the recent advances in proteomics with our knowledge of metabolic signalling pathways.

Does the study have dietary implications?

Fish and plants are rich in omega-3 fatty acids whereas animal meat is the main source for omega-6. The human brain is highly enriched in omega-3, so omega-3 consumption is beneficial during brain development in early childhood. Identifying the link between omega-3 and syntaxin should allow us to find new consumable substances that could be beneficial for neuronal growth.

Why do we need to know more about how omega-3 and omega-6 work?

They are widely marketed in shops and on the television, so we need to know how they act in our bodies. Knowing about syntaxin 3 might help us find drugs that enhance neuronal growth or to identify other metabolic pathways that regulate brain development.