Auditory System: Giant Synaptic Terminals, Endbulbs, and Calyces

The processing of sound by the brain requires tight coupling between acoustic events and brain activity. Auditory neurons must be capable of responding quickly and with high fidelity. Two pathways in the system rely on giant synaptic terminals to meet their functional demands. Endbulbs of Held and calyces of Held are large terminals that guarantee secure synaptic transmission. Intrinsic membrane properties endow the terminals with fast response and recovery times. Such specializations preserve timing information in the auditory system and allow sounds to be localized and sequences of sounds to be perceived as speech or melodies.