Modulation of auditory processing by behavioral state

描述(由申请者提供)：我们建议在高阶感觉运动区调查行为状态和感觉处理之间的复杂关系。在鸟类鸣声系统中，HVC核是连接听觉和发声运动通路的关键前脑核团。睡眠中或麻醉的鸣禽的HVC神经元对鸟自己的鸣叫(BOS)做出强有力的反应，这与听觉处理中的作用一致。令人惊讶的是，在清醒的鸟类中，这些神经元的反应相当不同，不再完全受BOS的影响。 因此，一个记录点的听觉反应可以在几个小时内从完全抑制到强烈变化。因为觉醒选择性地抑制HVC的听觉反应，而不影响听觉前脑结构场L，这是听觉皮质的鸟类类似物，我们假设HVC的听觉反应或直接传入它的听觉结构受到行为状态的变化的调制。我们将在成年斑马雀(Taeniopygia Guttata)中研究这些调节的机制。我们的目标是了解调节听觉反应的行为条件和机制。 在目标1中，我们建议利用我们的能力，通过对轻度镇静的鸟类进行短暂唤醒来抑制HVC的听觉反应，以确定传入HVC的听觉结构，其中唤醒首先抑制听觉反应。确定了这种结构后，我们将测试唤醒介导的听觉活动抑制的机制，方法是从HVC进行记录，同时在上面确定的目标结构中对神经调节系统进行药物操作。在AIM 2中，我们使用歌曲辨别任务来研究HVC的听觉反应是否受到注意的调节。我们假设注意力会增强HVC的听觉反应。在AIM 3中，我们建议记录鸟类在其群体中听到同种雄性鸟并与其相互作用时的HVC活动。我们假设，所听到的歌曲产生的行为背景以及歌手的身份将显著影响听觉反应。

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.