Apoptosis in auditory brainstem neurons after a severe noise trauma of theorgan of Corti: Intracochlear GDNF treatment reduces the number of apoptotic cells

We have studied the morphological and cellular changes in the cochlear nucl eus (CN) after cochlear nerve degeneration and whether these changes can be prevented by rescuing the primary cochlear neurons from degeneration with local glial cell line derived neurotrophic factor (GDNF) treatment, Degener ation of spiral ganglion neurons was seen to lead to a reduction of the vol ume of the anteroventral cochlear nucleus (AVCN); the size of the cell nucl ei in the AVCN also was reduced, No differences were observed in cell densi ty, After intrascalar GDNF treatment the volume of the AVCN was significant ly larger when compared to the untreated side, and the size of the cell nuc lei in the AVCN was significantly larger on the treated side, After degener ation of spiral ganglion neurons, an increased number of apoptotic cell nuc lei were seen in ipsilateral CN and superior olivary complex, This increase was significantly smaller after intrascalar GDNF treatment, Degeneration o f primary cochlear neurons seems to lead to an increase in the number of CN neurons undergoing apoptotic cell death, This can be prevented partially b y rescuing primary cochlear neurons from degeneration with local GDNF treat ment, Copyright (C) 2000 S. Karger AG, Basel.