Frequency selectivity of central auditory neurons without inner ear.
A group of neurons in the inferior colliculus (IC) of the chicken displayed frequency selectivity after surgical removal of both cochleae. Characteristic neuronal frequencies were evident in the following three measures. i) The cells fired spontaneously with discrete preferred interspike intervals; ii) Impulse responses of these neurons to electrical stimuli of cochlear nerves displayed oscillations at the preferred frequencies; iii) When the cochlear nerves were stimulated with a random pulse sequence, a reverse correlation analysis showed that the cells preferred the same frequencies in the stimulus input. Preferred frequencies observed thus far covered over 4 octaves of the auditory range. These "oscillating cells" were found only in a small rostromedial area in the IC. Neuronal frequency selectivity may serve a temporal analysis of sound and underlie sound identification with certain cochlear implants. It may also support interaural crosscorrelation necessary for directional hearing.
Rotary Hearing Centre, University of British Columbia, Vancouver, Canada.
D W
DW
Schwarz
A
A
Dezsö
P R
PR
Neufeld
D000818:Animals; D001306:Auditory Pathways / Q000502:physiology; D002645:Chickens; D003051:Cochlea / Q000502:physiology*; D003056:Cochlear Nerve / Q000502:physiology; D005072:Evoked Potentials, Auditory; D005260:Female; D007245:Inferior Colliculi / Q000166:cytology* / Q000502:physiology; D009474:Neurons / Q000502:physiology*