Functional maps of the primate cortex revealed by through-skull wide-field optical imaging

Abstract

The primate cerebral cortex is organized into specialized areas representing different functional modalities (e.g., vision, audition, touch) and their associations along a continuous surface. The functional maps of these areas, however, are often investigated in a single modality at a time. Here, we developed and applied to awake primates a polarization-enhanced wide-field optical imaging method for measuring cortical hemodynamics through the intact skull. Adjacent somatosensory, auditory, and visual cortices were noninvasively localized and rapidly parcellated in awake marmosets (Callithrix jacchus), a primate model featuring a smooth cortex. Detailed somatotopy, tonotopy, and retinotopy were also mapped out on an individual-subject basis, with a new pure-tone-responsive tonotopic gradient discovered outside the auditory core. Moreover, the motion-sensitive extent surrounding the primate-specific MT/V5 and the location of a face-sensitive patch were both revealed with respect to retinotopy. This approach provides a powerful tool for mapping the functional landscape across modalities in a single non-human primate subject, and thus opens new opportunities for probing how primate cortical system is organized to enable real-world behaviors.

Voice patches in the marmoset auditory cortex revealed by wide-field calcium imaging

“…Secondly, cranial window implantation. The artificial dura-based cranial window implantation procedure was previously described [28][29]52 . The artificial dura is made of silicone and is removable for maintenance under anesthesia.…”

“…Wide-field calcium imaging was performed using the XINTRINSIC setups developed in our lab. The details for XINTRINSIC setups were previously described [28][29]52 . Recordings were acquired using custom code in MATLAB (Mathworks, https://github.com/x-song-x/XINTRINSIC), with a resolution of 1920 ´ 1080 and a sampling rate of 20Hz (20 frames per second).…”