Auditory discrimination training rescues developmentally degraded directional selectivity and restores mature expression of GABAA and AMPA receptor subunits in rat auditory cortex
Auditory discrimination training rescues developmentally degraded directional selectivity and restores mature expression of GABAA and AMPA receptor subunits in rat auditory cortex
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DOI：
10.1016/j.bbr.2011.12.041
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发表时间：
2012-04-15
影响因子：
2.7
通讯作者：
Sun, Xinde
中科院分区：
文献类型：
--
作者：
Guo, Fei;Zhang, Jiping;Sun, Xinde
听觉频率辨别训练可以改善出生后早期脉冲噪声暴露引起的成年人初级听觉皮层频率表征和时间信息处理的恶化。在这项研究中，我们探讨了听觉空间辨别训练恢复方向选择性的神经机制。大鼠暴露于脉冲噪声在出生后的关键时期表现出减少听觉方向选择性，但可以成功地训练，以确定一个目标的声音刺激在一个特定的方位角，使用奖励视情况而定的听觉辨别任务（EXP大鼠）。相反，大鼠被动暴露于训练过程，但没有奖励正确识别的方位角（PNR大鼠）没有表现出改善和行为表现仍然显着低于EXP大鼠和控制（CON）大鼠饲养在正常的声波环境下。与年龄匹配的CON大鼠相比，未训练的噪声升高（NR和PNR）大鼠的听觉皮层中GABA（A）受体亚基α 1、α 3、β 2和β 3以及AMPA GluR 2亚基的表达水平显著改变，而训练的噪声升高（EXP）大鼠的表达水平与CON大鼠无显著差异。因此，奖励条件的声音方位辨别训练可以通过恢复听觉皮层中神经递质受体亚单位的适当表达谱来补救方向选择性，从而允许皮层神经元的正常空间选择性。听觉方向选择性的发展依赖于这些兴奋性和抑制性神经递质受体亚单位的调节表达;早期脉冲噪声可能通过干扰受体表达来破坏方向选择性的正常发展。(C)2012爱思唯尔有限公司版权所有。
Auditory frequency discrimination training can remediate deteriorated frequency representations and temporal information processing in the adult primary auditory cortex induced by early post-natal pulsed noise exposure. In this study, we investigated the neural mechanisms underlying the restoration of directional selectivity by auditory spatial discrimination training. Rats exposed to pulsed noise during a post-natal critical period demonstrated reduced auditory directional selectivity but could be successfully trained to identify a target sound stimulus at a specific azimuth angle using a reward-contingent auditory discrimination task (EXP rats). In contrast, rats passively exposed to the training procedure but no reward for correct identification of the azimuth angle (PNR rats) showed no improvement and behavioral performance remained significantly below EXP rats and control (CON) rats reared under a normal sonic environment. The expression levels of GABA(A) receptor subunits alpha 1, alpha 3, beta 2, and beta 3, and the AMPA GluR2 subunit were significantly altered in the auditory cortex of untrained noise-raised (NR and PNR) rats compared to age-matched CON rats, while trained noise-raised (EXP) rats exhibited levels of expression not significantly different from CON rats. Thus, reward-contingent sound-azimuth discrimination training may remediate directional selectivity by restoring the proper expression profile of neurotransmitter receptor subunits in the auditory cortex, allowing for normal spatial selectivity by cortical neurons. The development of auditory directional selectivity depends on the regulated expression of these excitatory and inhibitory neurotransmitter receptor subunits; early pulsed noise may disrupt the normal development of directional selectivity by interfering with receptor expression. (C) 2012 Elsevier B.V. All rights reserved.