Modulation of auditory processing by behavioral state

描述（由申请人提供）：我们建议调查行为状态和感觉处理之间的复杂关系，在高阶感觉运动区。在鸟类鸣唱系统中，HVC核是连接听觉和发声运动通路的关键前脑核团。与听觉处理中的作用一致，睡眠或麻醉的鸣禽中的HVC神经元对鸟自己的歌声（BOS）做出强烈反应。令人惊讶的是，在清醒的鸟类中，这些神经元的反应相当缓慢，不再只针对BOS。 因此，在一个记录点的听觉反应可以在几个小时内从完全抑制到鲁棒变化。由于觉醒选择性地抑制HVC听觉反应，而不影响听觉前脑结构场L，鸟类类似的听觉皮层，我们假设，在HVC的听觉反应，或听觉结构直接传入它，调制行为状态的变化。我们将探讨这些调制在成年斑胸草雀（Taeniopygia guttata）的机制。我们的目标是了解调节听觉反应的行为条件及其机制。 在AIM 1中，我们建议使用我们的能力，抑制听觉反应在HVC的短暂唤醒轻度镇静鸟类识别听觉结构传入HVC的唤醒首先抑制听觉反应。在确定了这个结构之后，我们将通过记录HVC来测试唤醒介导的听觉活动抑制机制，同时在上面确定的目标结构中操纵神经调节系统。在AIM 2中，我们使用歌曲辨别任务来研究HVC中的听觉反应是否受到注意的调制。我们假设，注意力会增强听觉反应的HVC。在AIM 3中，我们建议记录HVC活动，而鸟听到并与同种雄性在他的殖民地。我们假设，与听到的歌曲产生的行为背景，以及歌手的身份将显着影响听觉反应。

DESCRIPTION (provided by applicant): We propose to investigate the complex relationship between behavioral state and sensory processing in a high-order sensory-motor area. In the avian song system, nucleus HVC is a key forebrain nucleus that links auditory and vocal motor pathways. Consistent with a role in auditory processing, HVC neurons in sleeping or anesthetized songbirds respond robustly to the bird's own song (BOS). Surprisingly, in awake birds these same neurons respond quite variably and are no longer exclusively tuned to the BOS. Thus auditory responses at one recording site can vary over a few hours from complete suppression to robust. Because arousal selectively suppresses HVC auditory responses without affecting the auditory forebrain structure Field L, the avian analogue of the auditory cortex, we hypothesize that auditory responses in HVC, or auditory structures directly afferent to it, are modulated by changes in behavioral state. We will investigate the mechanism for these modulations in the adult zebra finch (Taeniopygia guttata). Our goal is to understand both the behavioral conditions that modulate auditory responses and the mechanism. In AIM 1, we propose to use our ability to suppress auditory responses in HVC by brief arousal of lightly sedated birds to identify the auditory structure afferent to HVC where arousal first suppresses auditory responses. Having identified this structure, we will then test the mechanism of arousal-mediated suppression of auditory activity by recording from HVC while pharmacologically manipulating neuromodulatory systems in the target structure identified above. In AIM 2, we use a song discrimination task to investigate whether auditory responses in HVC are modulated by attention. We hypothesize that attention will enhance auditory responses in HVC. In AIM 3, we propose to record HVC activity while the bird hears and interacts with conspecific males in his colony. We hypothesize that the behavioral context with which the heard song is produced as well as the identity of the singer will significantly influence auditory responses.