Increases resting-state PET activity after cochlear implantation in adult deafened cats

Abstract

Background and Objectives: For the hearing rehabilitation of patients with profound sensorineural hearing loss, cochlear implants (CIs) are widely used. However, the result of CI is variable, and the central neural plasticity is considered to be a reason for this variability. We hypothesize that the resting-state cortical networks play a role in the condition of profound hearing loss and are affected by CI. To investigate the resting-state neuronal networks after cochlear implantation, we acquired 18F-fluorodeoxyglucose (FDG)-positron emission tomography (PET) images in experimental animals.Materials and Methods:Eight domestic adult cats were enrolled in this study. The hearing threshold of the enrolled animals was within the normal range, as measured by auditory evoked potential. They were divided into two groups: control (n=4) and hearing loss (n=4) groups. Hearing loss was induced by co-administration of ethacrynate and kanamycin. FDG-PET was performed at normal hearing state and at 4 and 11 months after the deafening procedure. Cochlear implantation was performed in the right ear and electrical cochlear stimulation was performed for 7 months (from 4 to 11 months after the deafening procedure). Acquired PET images were analyzed and compared between the two groups and among the three time points.Results:At 4 months after hearing loss, the auditory cortical area