Environmental noise retards auditory cortical development.
The mammalian auditory cortex normally undergoes rapid and progressive functional maturation. Here we show that rearing infant rat pups in continuous, moderate-level noise delayed the emergence of adultlike topographic representational order and the refinement of response selectivity in the primary auditory cortex (A1) long beyond normal developmental benchmarks. When those noise-reared adult rats were subsequently exposed to a pulsed pure-tone stimulus, A1 rapidly reorganized, demonstrating that exposure-driven plasticity characteristic of the critical period was still ongoing. These results demonstrate that A1 organization is shaped by a young animal's exposure to salient, structured acoustic inputs-and implicate noise as a risk factor for abnormal child development.
Chang
Edward F
EF
W. M. Keck Center for Integrative Neuroscience, University of California, San Francisco, CA, USA. echang@itsa.ucsf.edu
Merzenich
Michael M
MM
D000161:Acoustic Stimulation; D000818:Animals; D000831:Animals, Newborn; D001303:Auditory Cortex / Q000254:growth & development* / Q000502:physiology; D001931:Brain Mapping; D004594:Electrophysiology; D005260:Female; D009473:Neuronal Plasticity; D009474:Neurons / Q000502:physiology*; D009622:Noise / Q000009:adverse effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors