Neural Integration of Audiovisual Sensory Inputs in Macaque Amygdala and Adjacent Regions

 Liang Shan1,2 · Liu Yuan1,3 · Bo Zhang1,7 · Jian Ma1  · Xiao Xu1  · Fei Gu3,4 · Yi Jiang3,4,5  · Ji Dai1,2,3,6
1 CAS Key Laboratory of Brain Connectome and Manipulation, the Brain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China 
2 Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions, Shenzhen 518055, China 
3 University of Chinese Academy of Sciences, Beijing 100049, China 
4 State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China 
5 Chinese Institute for Brain Research, Beijing 102206, China 
6 Shenzhen Technological Research Center for Primate Translational Medicine, Shenzhen 518055, China 
7 Key Laboratory of Brain Science, Zunyi Medical University, Zunyi 563000, China

Abstract

Integrating multisensory inputs to generate accurate perception and guide behavior is among the most critical functions of the brain. Subcortical regions such as the amygdala are involved in sensory processing including vision and audition, yet their roles in multisensory integration remain unclear. In this study, we systematically investigated the function of neurons in the amygdala and adjacent regions in integrating audiovisual sensory inputs using a semi-chronic multi-electrode array and multiple combinations of audiovisual stimuli. From a sample of 332 neurons, we showed the diverse response patterns to audiovisual stimuli and the neural characteristics of bimodal over unimodal modulation, which could be classified into four types with differentiated regional origins. Using the hierarchical clustering method, neurons were further clustered into five groups and associated with different integrating functions and sub-regions. Finally, regions distinguishing congruent and incongruent bimodal sensory inputs were identified. Overall, visual processing dominates audiovisual integration in the amygdala and adjacent regions. Our findings shed new light on the neural mechanisms of multisensory integration in the primate brain.


Keywords
Macaque; Amygdala; Multisensory; Audiovisual integration; Neural activity; Multichannel recording