You can't teach a middle−aged ganglion new tricks

Repeated imaging of the same individual neuron for over a year in mice allows the authors of a new study in this issue to show that presynaptic axon terminals become progressively more stable as the animals age, changing little after 6 to 12 months. A typical neuron has 10,000 neighbors, as compared to only tens or at most hundreds for other cells of the body. It matters, of course, not only how many neighbors you have but also which of your neighbors you talk to and who talks back to you. Furthermore, the complexity of the fully developed mammalian nervous system is many orders of magnitude larger than what could be possibly genetically determined. It is all the more important, therefore, to understand the rules governing neural (self−) organization, particularly during development, repair and adult plasticit