Establishing a genetic network diagram of the primate brain linked to social disorders is one of the major challenges of modern neurobiology and medicine. Nowhere is this need clearer than in social-emotional systems, where dysregulation of circuitry is implicated in mental illnesses: autism, depression and anxiety. We will generate multiple-gene-specific 3D reconstructions from serial sections of long range axon projections of social circuitry in primate, including hypothalamus, bed nucleus and stria terminalis, basal forebrain nuclei, amygdala and basal ganglia, and integrate with MRI. This will address two barriers to understanding primate brain and human social behavior; lack of knowledge of endogenous circuitry, and lack of computational systems for large scale multicolor axon projections in serial registration and for handling the terabyte datasets. We have generated a novel pipeline of multicolor confocal image acquisition integrated with a computational suite of algorithms for reconstructing and visualizing TB image sets. We have applied these to generate a 3D reconstruction of 45,295,200 images (1,620mm) at the axon level for social circuitry involving oxytocin (OT) and vasopressin (AVP) and the Williams syndrome gene, GTF2IRD1, all implicated in social behavior. We have identified novel OT and AVP structures and sparse tracts that may fill critical gaps as substrates and biomarkers for human behavior. Moreover, we have developed approaches for hierarchical 3D integration of axon-level images to MRI images. The proposal emerges from a unique multidimensional team and advisors*; experts in segmentation, large scale image reconstruction and 3D visualization (Tasdizen, Joshi, Pascucci, Roysam*), in primate brain circuitry and neuroanatomy (Angelucci, Hof*, Dong*, Korenberg), in animal and human MRI (Hsu, Joshi), and in genetics and multicolor fluorescence imaging of axon projections (Korenberg, Angelucci). We will: 1) Establish a genetic wiring diagram of axonal projections for OT, AVP and GTF2IRD1 in macaque. We will generate, validate and image more than 667 serial coronal sections (21,100mm) of macaque brains multicolor fluorescence immunohistochemistry of ligands and their receptors, using confocal microscopy and tract tracing. Pre-/post-mortem MRI(150-200mm resolution) and block-faces images will be acquired. Novel circuitry will be validated in cognate regions of human brain. 2) Build a Neural Information System that integrates and visualizes a multiscale volumetric TB dataset of primate genetic connectivity for social neuropeptides, aligned using automated slice-to-slice image registration at the resolution of axonal projections to MRI, and annotated neuroanatomy. The results will identify novel OT/AVP related social circuitry and establish a pipeline of integrated technologies for bridging (macro)connectome with (micro)axome and both with genetics of mental illness. These will provide novel biomarkers for disease features and receptor targets, and accelerate translating the dissonant orchestration of social behavior by neuropeptides to therapeutic harmony in humans.
Interagency Autism Coordinating Committee (IACC)
Autism Research Database (AFD)
