PDF(Pubmed)
Abstract：
Tonotopic organization of the auditory cortex has been extensively studied in many mammalian species using various methodologies and physiological preparations. Tonotopy mapping in primates, however, is more limited due to constraints such as cortical folding, use of anesthetized subjects, and mapping methodology. Here we applied a combination of through-skull and through-window intrinsic optical signal imaging, wide-field calcium imaging, and neural probe recording techniques in awake marmosets (Callithrix jacchus), a New World monkey with most of its auditory cortex located on a flat brain surface. Coarse tonotopic gradients, including a recently described rostral-temporal (RT) to parabelt gradient, were revealed by the through-skull imaging of intrinsic optical signals and were subsequently validated by single-unit recording. Furthermore, these tonotopic gradients were observed with more detail through chronically implanted cranial windows with additional verifications on the experimental design. Moreover, the tonotopy mapped by the intrinsic-signal imaging methods was verified by wide-field calcium imaging in an AAV-GCaMP labeled subject. After these validations and with further effort to expand the field of view more rostrally in both windowed and through-skull subjects, an additional putative tonotopic gradient was observed more rostrally to the area RT, which has not been previously described by the standard model of tonotopic organization of the primate auditory cortex. Together, these results provide the most comprehensive data of tonotopy mapping in an awake primate species with unprecedented coverage and details in the rostral proportion and support a caudal-rostrally arranged mesoscale organization of at least three repeats of functional gradients in the primate auditory cortex, similar to the ventral stream of primate visual cortex.
摘要：
已经使用各种方法和生理制剂在许多哺乳动物物种中广泛研究了听觉皮层的通视组织。灵长类动物的色调图，然而,由于皮质折叠等限制，使用麻醉对象，和映射方法。在这里，我们应用了穿过头骨和穿过窗口的固有光学信号成像的组合，宽场钙成像,和神经探针记录技术在清醒的猿猴（Callithrixjacchus），一种新世界猴子，它的听觉皮层大部分位于平坦的大脑表面。粗糙的色调梯度，包括最近描述的延髓-时间(RT)到Parabelt梯度，通过固有光学信号的颅骨成像揭示，随后通过单单元记录进行验证。此外，我们通过长期植入的颅骨窗对这些原位梯度进行了更详细的观察,并对实验设计进行了额外的验证.此外，在AAV-GCaMP标记的受试者中,通过宽场钙成像验证了通过固有信号成像方法绘制的色调图.经过这些验证，并进一步努力在窗口化和穿透头骨的受试者中更深入地扩大视野，在更靠近RT的区域观察到了另一个推定的液位素梯度，先前尚未通过灵长类听觉皮层的音调组织的标准模型进行描述。一起,这些结果提供了最全面的数据，在清醒的灵长类动物物种中具有前所未有的覆盖率和细节，并支持在灵长类听觉皮层中至少三个重复的功能梯度的尾端排列的中尺度组织，类似于灵长类视觉皮层的腹侧流。
