Abstract
Synaptic plasticity is essential for the function of neural systems. It sets up initial circuitry and adjusts connection strengths according to the maintenance requirements of its host networks. Like all things biological, synaptic plasticity must rely on genetic programs to provide the molecular components of its machinery to integrate ongoing, often multi-sensory experience without destabilising effects. Because of its fundamental importance to healthy behaviour, understanding plasticity is thought to hold the key to understanding the brain. There are innumerable ways to approach this topic and a complete review of its status quo would be impossible. In the current issue we dig into some of the finer points of synaptic plasticity, starting small, at the level of genes, and slowly zooming out to synapses, populations of synapses, and finally entire systems and brain regions. At each level, we tried to represent different perspectives, different systems, and approaches to the same questions to give a broad sampling of how synaptic plasticity is being studied.