Description
Calyx of Held giant presynaptic terminals in the medial nucleus of the trapezoid body of the auditory brainstem form axosomatic synapses that have advanced to one of the best-studied synaptic system of the mammalian brain. As the auditory system matures and adjusts to high fidelity synaptic transmission, the calyx undergoes extensive structural and functional changes: it is formed around postnatal day 3 (P3), achieves immature function until hearing onset around P10 and can be considered mature from P21 onwards. This setting provides the unique opportunity to examine the repertoire of genes driving synaptic structure and function.