Neurite pruning and neuronal cell death: spatial regulation of shared destruction programs

During development, neurons are initially overproduced and excess neurons are eliminated later on by programmed cell death. In a more refined developmental process termed pruning, excess axons and dendritic branches are removed while the cell body remains intact. In mature animals, axons that become disconnected as a result of injury are eliminated through a series of events collectively known as Wallerian degeneration. Recent evidence points to unexpected similarities between these three types of obliterative processes, as they share common regulators. These findings provide new ideas on how cellular destruction programs are spatially regulated in neurons.