The effects of auditory deprivation on morphological maturation of the ventral cochlear nucleus.
The volumes of the auditory brainstem nuclei and age-related auditory brainstem response (ABR) thresholds were analyzed in homozygote (je/je) and heterozygote (je/+) jerker mutant mice. Altogether 97 mice were used in the study. Je/je mice never develop any hearing. The dorsal (DCN) and ventral (VCN) cochlear nuclei were found to have stopped their growth at 56 days after birth. In je/+ mutants, ABR thresholds remained normal or near-normal for 3-6 months, whereas VCN and DCN volumes remained unchanged at least after 56 days after birth. There is no significant difference in DCN volume in je/je and je/+ mice. However, the VCN volume and the cross-sectional area of globular cells were both significantly larger in je/+ than in je/je mice (P less than 0.01). These findings show that auditory deprivation during the maturation of hearing in je/je mutants causes an incomplete maturation of only the ventral cochlear nucleus.
Anniko
M
M
Department of Oto-Rhino-Laryngology and Head & Neck Surgery, University Hospital, Umeå, Sweden.
Sjöström
B
B
Webster
D
D
D000818:Animals; D001309:Auditory Threshold; D001933:Brain Stem / Q000254:growth & development* / Q000502:physiology; D005072:Evoked Potentials, Auditory; D006309:Hearing / Q000502:physiology*; D051379:Mice; D008808:Mice, Inbred CBA; D008817:Mice, Mutant Strains; D012683:Sensory Deprivation / Q000502:physiology*