AUDITORY EXPERIENCE AND ADULT NEURON TURNOVER IN BIRDS

描述：（改编自申请人的摘要） 在包括人类在内的许多脊椎动物中，神经发生持续到成年期。安 了解控制神经元添加和存活的因素可能 最终深入了解成人神经发生的功能，并提出建议 大脑修复机制。在成年温血脊椎动物中，最 鸟类端脑广泛产生神经元。在 对于鸣禽来说，许多新的神经元被插入到高声中枢（HVC）中，这是一个 感知和产生习得发声所必需的区域。 新的 HVC 神经元取代了已死亡的旧神经元。最近的工作表明 听觉输入对于正常的神经元替换率是必要的。可用 数据表明，震耳欲聋的声音会减少 HVC 神经元的数量 并延长其随后的生存期。建议的工作将直接测试 已成功融入的神经元的寿命是否 震耳欲聋之前的 HVC 已增强。进一步的研究将确定是否 震耳欲聋会影响成年神经元的产生或早期存活。 病变研究将测试外侧大细胞核是否 前新纹状体 (lMAN) 是歌曲学习所必需的区域，参与 HVC 神经元周转的听觉控制。 播放同种歌曲会增加 HVC 神经元的活动率 通过播放鸟自己的歌声可以获得最大速率。因此， 震耳欲聋对 HVC 神经元更新的影响可能是由于剥夺了鸟类的 与歌曲相关的听觉刺激。拟议的实验将系统地 剥夺听力完好的鸟类获得自我产生的听觉反馈的机会 和/或同种歌曲来检验这个假设。我们将对比这些效果 通过以下操作进行更改，但不会完全阻止， 唱歌时自我产生的听觉反馈。总的来说，这些研究将 探索控制成人神经元添加的感觉要求和 控制学习的离散的、特征良好的神经系统中的损失 发声行为。

DESCRIPTION: (adapted from applicant's abstract) Neurogenesis persists into adulthood in many vertebrates including humans. An understanding of the factors that control neuron addition and survival may ultimately lead to insights on the functions of adult neurogenesis and suggest mechanisms for brain repair. In adult warm-blooded vertebrates, the most widespread production of neurons occurs in the avian telencephalon. In songbirds, many new neurons are inserted into the High Vocal Center (HVC), a region necessary for the perception and production of learned vocalizations. New HVC neurons replace older neurons that have died. Recent work shows that auditory input is necessary for normal rates of neuronal replacement. Available data suggest that deafening decreases the numbers of HVC neurons incorporated and prolongs their subsequent survival. Proposed work will directly test whether the life span of neurons that have been successfully incorporated into HVC prior to deafening is augmented. Additional studies will determine whether deafening influences the production or early survival of adult-formed neurons. A lesion study will test whether the lateral magnocellular nucleus of the anterior neostriatum (lMAN), an area necessary for song learning, participates in the auditory control of HVC neuron turnover. Playbacks of conspecific song produce increased rates of HVC neuron activity and maximal rates are obtained with playbacks of the bird's own song. Thus, the effects of deafening on HVC neuronal turnover may be due to depriving birds of song-related auditory stimulation. Proposed experiments will systematically deprive hearing-intact birds of access to self-generated auditory feedback and/or conspecific song to test this hypothesis. We will contrast these effects with those following manipulations that alter, without completely blocking, self-generated auditory feedback from singing. Collectively, these studies will explore the sensory requirements for the control of adult neuron addition and loss within a discrete, well-characterized neural system controlling a learned vocal behavior.