In this issue of Nature Reviews Neuroscience, Kamiguchi and colleagues examine how gradients of extracellular cues guide growth cones of developing axons towards their synaptic targets. In their Review on page 191, the authors propose a mechanism whereby these cues trigger an alteration in the balance of endocytosis and exocytosis across the growth cone, thereby biasing the direction of growth.

In our featured article on page 217, Mishkin — one of the proposers of the original 'two-streams' hypothesis of visual processing — and colleagues provide an updated view on the dorsal visual pathway. According to this new framework, the dorsal stream at the level of the parietal cortex gives rise to three pathways that support distinct functions: working memory, visually guided action and spatial navigation.

Differences between individuals are often treated as 'noise' in studies comparing multiple groups of people. However, such variability can be exploited to reveal the neural underpinnings of cognitive functions, as has been shown in studies that correlate neural activity with task performance. In a Perspective on page 231, Kanai and Rees focus on inter-individual differences in brain structure, showing that grey and white matter volume and surface area can predict performance in processes ranging from perception and motor control to higher cognitive functions.

Finally, on page 204, Trudeau and colleagues review the evidence that vesicular glutamate transporters are expressed not only in glutamatergic neurons, but also in neurons containing monoamines, acetylcholine or, intriguingly, GABA. They discuss the functional implications of such co-expression, including the possibility of glutamate co-release from non-glutamatergic neurons, as well as enhanced packaging of the 'primary' neurotransmitter — a process called vesicular synergy.