Stochasticity is the theme for two articles in this issue. On page 375, Triller and colleagues discuss stochastic influences on synaptic transmission. They explain that because synaptic transmission involves small quantities of different molecules, the stochastic aspects of these molecules' behaviour might contribute to — or disrupt — synaptic function, with important implications for synaptic plasticity.

Continuing with stochasticity, in a Perspective on page 415, McDonnell and Ward highlight how theoretical modelling and experimental approaches have shown that stochastic biological noise can improve information processing. To further understand the benefits of biologically relevant noise in neural systems, they propose a unifying framework that reconciles these two approaches.

Also in this issue, on page 388 David and Kroner discuss the contribution of macrophages and microglia to the inflammatory response after spinal cord injury. Following such trauma, these cell types often contribute to secondary tissue damage, but under certain conditions they can exhibit anti-inflammatory and reparative properties. The authors examine the macrophage polarization process that determines the cells' functional properties. Modulation of the factors that regulate this process might be a useful strategy for treating spinal cord injuries.

Finally, on page 400, Heinz and colleagues consider alcohol's ability to increase the propensity of certain individuals to act violently. The authors review animal and human studies that have begun to reveal the genetic and environmental factors that modulate frontal and limbic brain function and thereby predispose to both alcohol consumption and aggression. In individuals with such increased vulnerability, acute alcohol intake is more likely to elicit aggressive behaviour.