Sensory-motor integration in the auditory dorsal stream

 描述(申请人提供)：两条皮质通路起源于听觉皮质的主要核心区：腹侧通路，辅助声音识别；背侧通路，最初被定义为空间和运动的处理流，类似于视觉系统。我们最近提出，应该在更广泛的意义上将这一背侧通路重新定义为感觉运动整合和控制的加工流(Rauscheck ker，2011)。这一更广泛的功能明确地包括空间处理，但也扩展到时间序列的处理，包括人类的口语和音乐旋律。在这个项目中，我们将通过训练恒河猴在新设计的行为仪器(猴子钢琴)上产生固定的声音序列来测试听觉背流的扩展模型。通过按下一个杠杆，猴子将产生一个特定音调的音乐音调；通过连续按下几个杠杆，猴子将产生一种旋律。在猴子学会可靠地演奏相同的旋律后，我们将对清醒的猴子进行听觉反应大脑区域的功能性磁共振成像(FMRI)，同时它听着学习的自我生成的序列。控制刺激包括猴子通过听另一只猴子演奏同样的时间被动地接触到的旋律，以及猴子以前从未听过的新奇旋律。初步数据表明，由自身产生的旋律激活的区域包括顶叶下部皮质的一个区域，以及背侧和腹侧运动前皮质各一个焦点。激活区域的位置将指导随后使用线性微电极阵列(LMA)的电生理记录。每个记录地点都将使用相同的序列进行测试。接下来，我们将记录运动前皮质对被动聆听声音序列的神经元反应，并将它们与猴子主动产生声音序列时获得的神经元活动进行比较。最后，我们将添加猴子在猴子钢琴上演奏声音序列的视频，并使用fMRI和LMAS研究背侧流的多感觉相互作用。特别是，尾侧听带和副耳垂的反应将在同步记录中与下顶叶和运动前皮质的反应进行比较。我们的研究使用在行为任务中训练的警觉猴子，将有助于理解跨感觉系统的感知和认知的统一原则，以及它们与运动系统的相互作用。研究非人类灵长类动物的听觉背根流将为人类语言和音乐的进化提供有价值的信息。我们的研究与听觉和言语的高级加工障碍高度相关，如构音障碍、言语失用、失语症和涉及感觉和运动系统之间协调不足的特定语言障碍。研究结果还将提高我们对感觉-运动整合障碍的理解，如共济失调，这可能是由中风或神经退行性疾病引起的，从而导致更好的治疗和康复策略。

 DESCRIPTION (provided by applicant): Two cortical pathways originate from primary core areas of auditory cortex: a ventral pathway subserving identification of sounds, and a dorsal pathway, which was originally defined - similar to the visual system - as a processing stream for space and motion. We have recently proposed that this dorsal pathway should be redefined in a wider sense as a processing stream for sensorimotor integration and control (Rauschecker, 2011). This broader function explicitly includes spatial processing but also extends to the processing of temporal sequences, including spoken speech and musical melodies in humans. In this project, we will test the expanded model of the auditory dorsal stream by training rhesus monkeys to produce fixed sound sequences on a newly designed behavioral apparatus ("monkey piano"). By pressing a lever the monkey will produce a musical tone of a specific pitch; by pressing several levers in succession, the monkey will produce a melody. After a monkey has learned to reliably play the same melody, we will perform functional magnetic resonance imaging (fMRI) of auditory-responsive brain regions in the awake monkey while it listens to the learned self-generated sequence. Control stimuli include melodies the monkey has been passively exposed to by listening to another monkey play for the same amount of time, and novel melodies that the monkey never heard before. Preliminary data suggest that areas activated by the self-generated melody include a region in inferior parietal cortex as well as one focus each in dorsal and ventral premotor cortex. The locations of activated regions will guide subsequent electrophysiological recording with linear microelectrode arrays (LMAs). Each recording site will be tested with the same sequences. Next we will record neuronal responses in premotor cortex to passive listening of the sound sequences and compare them to neuronal activity obtained when the monkey actively produces the sequence with and without sound. Finally, we will add video of a monkey playing the sound sequence on the monkey piano and study multisensory interactions along the dorsal stream using fMRI and LMAs. In particular, responses in caudal auditory belt and parabelt will be compared with those in inferior parietal and premotor cortex in simultaneous recordings. Our studies, using alert monkeys trained in a behavioral task, will contribute to the understanding of unified principles of perception and cognition across sensory systems and their interactions with the motor system. Investigating the auditory dorsal stream in a nonhuman primate will provide valuable information about the evolution of speech and music in humans. Our studies are highly relevant for higher-order processing disorders of audition and speech, such as dysarthria, apraxia of speech, aphasia and specific language disorders which involve inadequate coordination between sensory and motor systems. The results will also improve our understanding of disorders of sensory-motor integration, such as ataxia, which may be caused by stroke or neurodegenerative disease, thus, leading to better therapies and rehabilitation strategies.