The generation and systematic characterisation of driver lines labelling a large number of neurons in the Drosophila innate olfactory processing centre bridges electron microscopy neuronal reconstructions, circuits and behaviour.

A combination of genetic, anatomical and physiological techniques has revealed that the lateral horn, a region of the brain involved in olfaction in flies, has many more types of neurons than expected.

The lateral horn can be classified into three functional odor response domains that decode opposing hedonic valences and odor intensity.

The Drosophila lateral horn, a higher olfactory brain area, contains >165 genetically defined cell types with stereotyped odour responses across animals and improved odor categorisation compared with their inputs.

Adult neurogenesis, although happening at a slow rate in the adult brain, plays an important role in learning and memory and has the ability to powerfully modulate large scale neural networks.

Habituation to brief olfactory stimulation is biphasic and mediated by distinct neuronal circuits where an initial latency phase is rapidly followed by stimulus devaluation signifying behavioral habituation in Drosophila.

Analysis of experiments on bacteria suggests that the dependence of cell size on growth rate is not an adaptation but a causal consequence of a regulatory mechanism that controls DNA replication.

The use of X-rays to investigate why bones break could lead to treatments that reduce the number of elderly people who suffer broken hips.

The biomedical research enterprise in the US has become unsustainable and urgent action is needed to address a variety of problems.

Theoretical ideas have a rich history in many areas of biology, and new theories and mathematical models have much to offer in the future.