High-fidelity transmission of sensory information by single cerebellar mossy fibre boutons

Synaptic boutons, the points of communication between nerve cells, are so tiny that it has been impossible to record their electrical activity without slicing the brain. In a technical tour de force, Rancz et al. provide the first intracellular recordings from presynaptic boutons in the intact mammalian brain. Their results contradict the prevailing views — derived from in vitro work — on how the cerebellum integrates sensory information to control movement, by revealing an unexpected sensitivity of single brain connections to stimuli from the environment.