Optical intrinsic signal imaging with optogenetics reveals functional cortico-cortical connectivity at the columnar level in living macaques

• Published in: Scientific reports Vol. 9; no. 1; p. 6466
• Main Authors: Nakamichi, Yu, Okubo, Kai, Sato, Takayuki, Hashimoto, Mitsuhiro, Tanifuji, Manabu
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.04.2019; Nature Publishing Group
• Subjects: 13/44; 631/378/2613/1875; 631/378/2649; 631/378/3920; Animals; Cerebral cortex; Cerebral Cortex - diagnostic imaging; Cerebral Cortex - metabolism; Cerebral hemispheres; Channelrhodopsins - biosynthesis; Cognitive ability; Connectome; Functional magnetic resonance imaging; Genetics; Humanities and Social Sciences; Information processing; Macaca mulatta; Magnetic Resonance Imaging; Male; multidisciplinary; Neural networks; Neurons - cytology; Neurons - metabolism; Optical Imaging; Optics; Optogenetics; Science; Science (multidisciplinary); Structure-function relationships
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-42923-2

Despite extensive research on primate cognitive function, understanding how anatomical connectivity at a neural circuit level relates to information transformation across different cortical areas remains primitive. New technology is needed to visualize inter-areal anatomical connectivity in living monkeys and to tie this directly to neurophysiological function. Here, we developed a novel method to investigate this structure-function relationship, by combining optical intrinsic signal imaging (OISI) with optogenetic stimulation in living monkeys (opto-OISI). The method involves expressing channelrhodophsin-2 in one area (source) followed by optical imaging of optogenetic activations in the other area (target). We successfully demonstrated the potential of the method with interhemispheric columnar projection patterns between V1/V2 border regions. Unlike the combination of optogenetics and functional magnetic resonance imaging (opto-fMRI), opto-OISI has the advantage of enabling us to detect responses of small clusters of neurons, even if the clusters are sparsely distributed. We suggest that opto-OISI can be a powerful approach to understanding cognitive function at the neural circuit level, directly linking inter-areal circuitry to fine-scale structure and function.