Decoding the Neuronal Tower of Babel

摘要

Individual neurons in the mammalian central nervous system communicate with their downstream targets by means of subcellular specializations in their axon. Arranged like pearls on a necklace, these pre-synaptic terminals enable the rapid release of neurotransmitter in response to an electrical action-potential wave front that travels from the cell body to the far reaches of the axon. A single axon may contact hundreds of downstream targets, including numerous distinct cell types. Though separated by only a few micrometers, each of these presynap-tic release sites is often tuned to the particular cell type it innervates such that transmission may be robust onto one particular cell type yet weak at another, despite all terminals sensing the same action-potential waveform (1).