The fortieth annual Society for Neuroscience meeting this year welcomed over 30,000 delegates and was again a resounding success, with talks and posters pointing to important developments and approaches in neuroscience, several of which will feature in forthcoming issues of Nature Reviews Neuroscience.

MicroRNAs (miRNAs) control post-transcriptional protein expression and as such have emerged as regulators of many physiological events. In this issue, we publish a Review by Gerhard Schratt on the roles of miRNAs in the regulation of synapse formation and function and their potential involvement in higher-order processing (page 842). A Progress article by Eacker, Dawson and Dawson (page 837) discusses the emerging role of miRNAs in neuroprotection and neurodegeneration.

Structural and synaptic plasticity provide the brain with the potential to adapt and reorganize. On page 861, Murphy and Corbett review the compensatory changes that occur in the brain during recovery after stroke and highlight their parallels with plasticity during development. In a provocative article on page 873, Wandell and Smirnakis review studies of plasticity in adult primary visual cortex (V1). They argue that although the current view is that V1 is highly plastic, inconsistencies across studies indicate that plasticity in adult V1 may in fact be limited.

As this year draws to an end, we would like to thank our authors and referees, as well as our Highlight advisors, for their contributions in the year 2009 and our readers for their continuing support and interest. We are looking forward to continuing to provide the neuroscience community with more exciting and thought-provoking articles in 2010. If you would like to get in touch with the editorial team, please don't hesitate to send us an e-mail on