Postnatal Maturation of the Cochlear Neclei in the Cat: a Neurophysiological Study

The study of the postnatal maturation of the ventral cochlear nuclei (VCN) and the dorsal cochlear nuclei (DCN) was carried out on the cat by means of recordings of the extra-cellular neuronal activity. At birth it is already possible to obtain toneburst responses in the VCN and DCN. At this age the responses are characterised by a small number of spikes grouped in three bursts when the tone-bursts lasted 500 msec. Subsequently, the number of bursts increases until, from 9 or 10 days onwards the responses become sustained. These responses do not acquire their adult characteristics until more than a month after birth. During postnatal maturation of the cochlear nuclei, the VCN is distinguishable from the DCN by the greater number of units revealing spontaneous activity. Another criterion, such as latency, differentiates the VCN from the DCN from the point of view of the kinetics of maturation.