TY - JOUR T1 - Refining Cortical Representation of Sound Azimuths by Auditory Discrimination Training JF - The Journal of Neuroscience JO - J. Neurosci. SP - 9693 LP - 9698 DO - 10.1523/JNEUROSCI.0158-13.2013 VL - 33 IS - 23 AU - Ying Zhang AU - Yan Zhao AU - Xiaoqing Zhu AU - Xinde Sun AU - Xiaoming Zhou Y1 - 2013/06/05 UR - http://www.jneurosci.org/content/33/23/9693.abstract N2 - Although training-based auditory cortical plasticity in the adult brain has been previously demonstrated in multiparametric sound domains, neurochemical mechanisms responsible for this form of plasticity are not well understood. In this study, we trained adult rats to identify a target sound stimulus at a specific azimuth angle by using a reward-contingent auditory discrimination task. We found that auditory spatial discrimination training significantly enhanced representation of sound azimuths in the primary auditory cortex, as shown by sharper azimuth-selective curves and more evenly distributed best angles of cortical neurons. Training also facilitated long-term potentiation of field potentials in the primary auditory cortex induced by theta burst stimulation of the white matter. In parallel, there were significant alterations in expression levels of certain cortical GABAA and NMDA receptor subunits, resulting in a marked decrease in the level of GABAA relative to NMDA receptors. These changes in the expression profile of inhibitory and excitatory neurotransmitter receptor subunits might enhance synaptic transmission, thereby facilitating training-induced cortical plasticity in the spatial domain. ER -