Razak Khaleel A, Richardson Marlin D, Fuzessery Zoltan M
Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA.
Proc Natl Acad Sci U S A. 2008 Mar 18;105(11):4465-70. doi: 10.1073/pnas.0709504105. Epub 2008 Mar 11.
Frequency modulated (FM) sweeps are common components of vocalizations, including human speech. How developmental experience shapes neuronal selectivity for these important signals is not well understood. Here, we show that altered developmental experience with FM sweeps used in echolocation by the pallid bat leads to either a loss of sideband inhibition or millisecond delays in the timing of inhibitory inputs, both of which lead to a reduction in rate and direction selectivity in auditory cortex. FM rate selectivity develops in an experience-independent manner, but requires experience for subsequent maintenance. Direction selectivity depends on experience for both development and maintenance. Rate and direction selectivity are affected by experience over different time periods during development. Altered inhibition may be a general mechanism of experience-dependent plasticity of selectivity for vocalizations.
调频（FM）扫描是包括人类语音在内的发声的常见组成部分。发育经历如何塑造神经元对这些重要信号的选择性尚不清楚。在这里，我们表明，苍白蝙蝠用于回声定位的调频扫描的发育经历改变，会导致边带抑制丧失或抑制性输入时间出现毫秒级延迟，这两者都会导致听觉皮层中速率和方向选择性降低。调频速率选择性以与经验无关的方式发展，但后续维持需要经验。方向选择性在发育和维持过程中都依赖于经验。速率和方向选择性在发育过程中的不同时间段受到经验的影响。抑制的改变可能是发声选择性的经验依赖性可塑性的一般机制。
