Mattias Alenius

Research interest

The main focus in our lab is to understand how neurons and glia get their specific properties and functions. A topic that touches several basic questions in neuroscience and biology in general: How is a cell lineage formed? How is lineage translated into a cell fate? How is fate determination coupled to axon targeting? How can a biological system get so fine tuned that it invariably generate a certain number of cells?

We are addressing these questions in the olfactory system. In this system all these questions are directly reflected in the problem of odorant receptor choice. How do individual olfactory neurons select, from among a large repertoire, which receptor to express? The problem is formidable in its precision and dimension: In both mammals and most invertebrates each class of ORN express only one OR, generating large scattered groups of similar neurons. Moreover, many receptors are expressed in predetermined spatial domains of the olfactory fields. The complexity of this system thus presents a challenging problem for regulatory biology.

We are working with Drosophila since it provides a particularly interesting system in which to address this problem because its olfactory system has been described in great detail at both cellular and molecular levels, and has a striking complexity and precision of organisation. The fly contains two olfactory organs, the antennae and maxillary palps that together harbour 1300 ORNs. We have studied the expression of all 60 ORs. We found 42 to be expressed in these two organs in 38 ORN groups projecting to 38 glomeruli in the olfactory centre of Drosophila, the antennal lobe. Thus, we created an almost complete anatomical, molecular and functional map of the Drosophila olfactory system that sets the stage for a general analysis how this highly complex organisation is generated during development.