PT - JOURNAL ARTICLE AU - Etienne de Villers-Sidani AU - Edward F. Chang AU - Shaowen Bao AU - Michael M. Merzenich TI - Critical Period Window for Spectral Tuning Defined in the Primary Auditory Cortex (A1) in the Rat AID - 10.1523/JNEUROSCI.3227-06.2007 DP - 2007 Jan 03 TA - The Journal of Neuroscience PG - 180--189 VI - 27 IP - 1 4099 - http://www.jneurosci.org/content/27/1/180.short 4100 - http://www.jneurosci.org/content/27/1/180.full SO - J. Neurosci.2007 Jan 03; 27 AB - Experience-dependent plasticity during development results in the emergence of highly adapted representations of the external world in the adult brain. Previous studies have convincingly shown that the primary auditory cortex (A1) of the rat possesses a postnatal period of sensory input-driven plasticity but its precise timing (onset, duration, end) has not been defined. In the present study, we examined the effects of pure-tone exposure on the auditory cortex of developing rat pups at different postnatal ages with a high temporal resolution. We found that pure-tone exposure resulted in profound, persistent alterations in sound representations in A1 only if the exposure occurred during a brief period extending from postnatal day 11 (P11) to P13. We also found that postnatal sound exposure in this epoch led to striking alterations in the cortical representation of sound intensity.