Mesoscopic-scale functional networks in the primate amygdala

The primate amygdala performs multiple functions that may be related to the anatomical heterogeneity of its nuclei. At the level of single neurons, each function is reflected in stimulus- and task-specific responses. Given that neurons with a particular response profile are not clustered in any of the nuclei, single units may be too fine-grained to shed light on the mesoscale organization of the amygdala. We have extracted from local field potentials recorded simultaneously from multiple locations within the primate amygdala (Macaca mulatta) spatially defined and statistically separable responses to visual, tactile, and auditory stimuli. A generalized eigendecomposition-based method of source separation isolated coactivity patterns, or components, that in neurophysiological terms correspond to putative subnetworks. Some component spatial patterns mapped onto the anatomical organization of the amygdala, while other components reflected integration across nuclei. These components differentiated between visual, tactile, and auditory stimuli suggesting the presence of functionally distinct parallel subnetworks.