Journal of Neurophysiology, Vol 38, Issue 5 1208-1216, Copyright © 1975 by APS

ARTICLES

Inferior colliculus. II. Development of tuning characteristics and tonotopic organization in central nucleus of the neonatal cat

L. M. Aitkin and D. R. Moore

Tuning curves were measured for 65 units in the inferior colliculus of seven anesthetized kittens aged from 6 to 28 days. At 2 days of age the inferior colliculus was divisible into central, pericentral, and external nuclei. Evidence was found for broader tuning curves to occur in the pericentral nucleus compared with the central nucleus, as has been observed in the adult. The middle ear was filled with serous fluid to 6 days, while the external auditory meatus remained collapsed until 10 days. Central nucleus tuning curves in kittens were relatively flat with high thresholds. Best-frequency thresholds diminished from a mean of near 100 dB SPL at 6-11 days to near 50 dB in the adult. The marked drop in thresholds between days 22 and 21 led to the adoption of the sharp form of tuning curve common for adults. Tonotopic organization of the central nucleus was clear at day 11. Speculations were advanced about the dependence of central auditory maturations on cochlear development, axon myelination in the auditory pathway, and changes in synaptic density as a function of age.

This article has been cited by other articles:

				A. Kral, J. Tillein, S. Heid, R. Hartmann, and R. Klinke Postnatal Cortical Development in Congenital Auditory Deprivation Cereb Cortex, May 1, 2005; 15(5): 552 - 562. [Abstract] [Full Text] [PDF]

				D. R Moore Auditory development and the role of experience Br. Med. Bull., October 1, 2002; 63(1): 171 - 181. [Abstract] [Full Text] [PDF]