Tonotopic mapping in auditory cortex of the adult chinchilla with amikacin-induced cochlear lesions.
We have found a reorganization of tonotopic maps (based on neuron response thresholds) in primary auditory cortex of the adult chinchilla after amikacin-induced basal cochlear lesions. We find an over-representation of a frequency that corresponds to the border area of the cochlear lesion. The reorganization observed is similar in extent to that previously seen in a developmental model. The properties of neurons within the over-represented area were investigated in order to determine whether their responses originated from a common input (an indication of true plasticity) or represented only the result of truncating the activity of the sensory epithelium ("pseudo-plasticity"). Some aspects of our data fit with a true plasticity model and indicate the potential for the deafferented cortex of the mature cortex to regain connections with the surviving sensory epithelium.
Kakigi
A
A
Department of Otolaryngology, The Hospital for Sick Children, University of Toronto, Ontario, Canada.
Hirakawa
H
H
Harel
N
N
Mount
R J
RJ
Harrison
R V
RV
D000583:Amikacin / Q000009:adverse effects*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects*; D001303:Auditory Cortex / Q000033:anatomy & histology* / Q000502:physiology; D001309:Auditory Threshold / Q000502:physiology; D002682:Chinchilla; D015834:Cochlear Diseases / Q000139:chemically induced* / Q000473:pathology; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D006198:Hair Cells, Auditory / Q000473:pathology; D009473:Neuronal Plasticity / Q000502:physiology; D009474:Neurons / Q000473:pathology
D000900:Anti-Bacterial Agents; D000583:Amikacin