INTRACELLULAR RESPONSES OF THE RAT COCHLEAR NUCLEUS TO SOUND AND ITS ROLE IN TEMPORAL CODING

THE anteroventral cochlear nucleus (AVCN), the first centre of the cen tral auditory pathway, contains globular bushy cells, which are unique in their ability to produce fast excitatory post-synaptic potentials (EPSPs). Using in vivo intracellular recordings in the rat AVCN we exa mined these fast EPSPs in relation to temporal coding. At frequencies up to 2.5 kHz, EPSPs were evoked on successive sine waves of the stimu lus with EPSP summation limited. This one-to-one relationship between the EPSPs and the sound wave period was present at higher frequencies and over a greater intensity range than far action potentials. These r esults suggest that temporal coding is possible in globular bushy neur ones by their ability to extract temporal information through fast pro cessing of convergent presynaptic input.