As this month's issue goes to press we eagerly anticipate this year's Society for Neuroscience meeting in Chicago, which as always promises to bring together scientists from all fields of neuroscience. The meeting often leads to an interest in topics that might not be directly related to one's own field of research. The articles in this issue cover a broad range of topics and aim to draw attention to what are perhaps undervalued issues and inspire new streams of thought.

Sensi and colleagues (page 780) consider the often underappreciated role of zinc in the nervous system. The development of specific tools for monitoring changes in intra- and extracellular zinc concentrations has allowed us to study the effect of these changes on the function of the nervous system. The article reviews the neuronal mechanisms of zinc homeostasis, zinc's emerging role in modulating synaptic plasticity and the contribution of zinc dysregulation to pathological conditions such as stroke and Alzheimer's disease.

The Allen Brain Atlas, an online atlas of gene expression in the mouse brain, was launched over 5 years ago and is a valuable resource in neuroscience research. In their Perspective article on page 821, Jones and colleagues describe the initial challenges that faced this huge endeavour and discuss new developments and future opportunities.

Finally, we publish a Review by Allan Hobson (page 803) in which he reflects on the function of rapid eye movement (REM) sleep and dreaming. He proposes that, as REM sleep emerged late in evolutionary history and begins early in mammalian development, brain activity during REM sleep might constitute a state of protoconsciousness that prepares the brain for (and, after birth, reacts to) the experiences of waking life.