Imaging of Functional Connectivity in the Mouse Brain

Functional neuroimaging (e.g., with fMRI) has been difficult to perform in mice, making it challenging to translate between human fMRI studies and molecular and genetic mechanisms. A method to easily perform large-scale functional neuroimaging in mice would enable the discovery of functional correlates of genetic manipulations and bridge with mouse models of disease. To satisfy this need, we combined resting-state functional connectivity mapping with optical intrinsic signal imaging (fcOIS). We demonstrate functional connectivity in mice through highly detailed fcOIS mapping of resting-state networks across most of the cerebral cortex. Synthesis of multiple network connectivity patterns through iterative parcellation and clustering provides a comprehensive map of the functional neuroarchitecture and demonstrates identification of the major functional regions of the mouse cerebral cortex. The method relies on simple and relatively inexpensive camera-based equipment, does not require exogenous contrast agents and involves only reflection of the scalp (the skull remains intact) making it minimally invasive. In principle, fcOIS allows new paradigms linking human neuroscience with the power of molecular/genetic manipulations in mouse models

Diffusion tractography and neuromotor outcome in very preterm children with white matter abnormalities

BACKGROUND: Moderate-to-severe white matter abnormality (WMA) in the newborn has been shown to produce persistent disruptions in cerebral connectivity but does not universally result in neurodevelopmental disability in very preterm (VPT) children. The aims of this hypothesis-driven study were to apply diffusion imaging to: (i) examine whether bilateral WMA detected in VPT children in the newborn period can predict microstructural organization at the age of 7 y and (ii) compare corticospinal tract and corpus callosum (CC) measures in VPT children at the age of 7 y with neonatal WMA with normal vs. impaired motor functioning. METHODS: Diffusion parameters of the corticospinal tract and CC were compared between VPT 7-y olds with (n = 20) and without (n = 42) bilateral WMA detected in the newborn period. For those with WMA, diffusion parameters were further examined. RESULTS: Microstructural organization of corticospinal tract and CC tracts at the age of 7 y were altered in VPT children with moderate-to-severe WMA detected at term equivalent age as compared with those without injury. Furthermore, diffusion parameters differed in the CC for children with WMA categorized by motor outcome (n = 8). CONCLUSION: WMA on conventional magnetic resonance imaging at term equivalent age is associated with altered microstructural organization of the corticospinal tract and CC at 7 y of age

Development of human brain cortical network architecture during infancy

The brain’s mature functional network architecture has been extensively studied but the early emergence of the brain’s network organization remains largely unknown. In this study, leveraging a large sample (143 subjects) with longitudinal rsfMRI scans (333 datasets), we aimed to characterize the important developmental process of the brain’s functional network architecture during the first two years of life. Based on spatial independent component analysis and longitudinal linear mixed effect modeling, our results unveiled the detailed topology and growth trajectories of nine cortical functional networks. Within networks, our findings clearly separated the brains networks into two categories: primary networks were topologically adult-like in neonates while higher-order networks were topologically incomplete and isolated in neonates but demonstrated consistent synchronization during the first two years of life (connectivity increases 0.13~0.35). Between networks, our results demonstrated both network-level connectivity decreases (−0.02~−0.64) and increases (0.05~0.18) but decreasing connections (n=14) dominated increasing ones (n=5). Finally, significant sex differences were observed with boys demonstrating faster network-level connectivity increases among the two frontoparietal networks (growth rate was 1.63e-4 per day for girls and 2.69e-4 per day for boys, p<1e-4). Overall, our study delineated the development of the whole brain functional architecture during the first two years of life featuring significant changes of both within- and between-network interactions