Auditory central nervous system plasticity: application to cochlear implantation

Abstract

There are two types of plasticity in the central auditory nervous system. The first type occurs during the development of neural connections within a critical period after birth. The second type of plasticity results from a change in the central representation of neurons in the mature animal after neural connectivity has been established. Evidence of a critical period for plasticity central auditory system has been demonstrated in the ferret where a marked loss of neurons in the cochlear nucleus occurs after ablation of the cochlea five days after birth (Moore, 1990). However, ablation of the cochlea 24 days post-partem (i.e. a week before the onset of hearing) has little effect.