●Parsing the polarity code. Macara, I. G. Nature Reviews Molecular Cell Biology March (2004) Par proteins are core components in the process of cell polarization. They were first discovered in worms, but are conserved throughout metazoans, in which they are involved in many processes that are related to polarity. How do these diverse proteins interact with each other and with other polarity proteins?

●Neurodegenerative diseases and oxidative stress. Barnham, K. J., Masters, C. L. & Bush, A. I. Nature Reviews Drug Discovery March (2004)

●Listening to your heart: interoceptive awareness as a gateway to feeling. Bechara, A. & Naqvi, N. Nature Neuroscience February (2004) In this News and Views article, Bechara and Naqvi discuss a recent imaging study that indicates that body awareness, mediated by the anterior insular cortex, might contribute to the intensity of negative emotions.

●Twenty questions: state of ion channel research in 2004. The Nature Reviews Drug Discovery Ion Channel Questionnaire Participants Nature Reviews Drug Discovery March (2004)

●Localized striatal delivery of GDNF as a treatment for Parkinson disease. Kirik, D. et al. Nature Neuroscience February (2004) In this Perspective article, Kirik and colleagues discuss the effects of the neurotrophic factor GDNF in models of Parkinson's disease and in human patients. They emphasize that the method and site of delivery of the factor are crucial if it is to be an effective treatment.

●Storing memories in dendritic channels. Häusser, M. Nature Neuroscience February (2004)

●Tumour-suppressor function in the nervous system. Baker, S. J. & McKinnon, P. J. Nature Reviews Cancer March (2004) Mutations of tumour suppressor genes result in unique outcomes in the nervous system that contrast with their roles in other organs. How can studying the tissue-specific functions of tumour suppressors in the nervous system help us to understand signalling pathways that are relevant to cancer, and what are the therapeutic implications of this?

●Ion channels: shake, rattle or roll? Blaustein, R. O. & Miller, C. Nature 5 February (2004)

●The most important sexual organ. Carina Dennis Nature 29 January (2004) New evidence indicates that the brain begins to develop differently in males and females much earlier than was thought — before sex hormones come into play. In this News Feature, Carina Dennis considers the implications.