When trying to describe what inspires people to study the development of the nervous system, a line from Robert Louis Stevenson's El Dorado constantly springs to mind — “To travel hopefully is a better thing than to arrive”. The adult brain is undoubtedly fascinating, but developmental neuroscientists are more concerned with the journey that brings it to this state than with the destination itself. In fact, it might be argued that the journey never really ends, because neuronal circuits in the brain are continually modified throughout life.

In this focus on neural development, our journey begins with neural induction — Schoenwolf introduces us to the work of the pioneering embryologists who laid the foundations for studying this process. Jan and Jan then show how asymmetric cell division can generate neuronal diversity. But neural development is not just a matter of generating neurons; they must also go to the right places and make the right connections. Marín and Rubenstein describe the mechanisms of tangential neuronal migration in the developing cortex, and Sanes and Lichtman consider synaptogenesis in the context of the neuromuscular junction.

With an ever-expanding range of molecular markers at our disposal, you would imagine that we would be better equipped than ever to identify different cell types during neurogenesis. Yet researchers are starting to question the specificity and reliability of these markers and, after recent claims that non-neural stem cells can generate neurons, the definition of a neural stem cell is becoming blurred. In the Perspectives section, four articles discuss the use of markers in neuroscience, and consider how methods for detecting neurons and glia might be improved.

We hope that this focus will give you a taster for some of the questions that have occupied the minds of developmental neuroscientists for over a century. Enjoy the trip!