Magnetic resonance imaging enables the noninvasive mapping of both anatomical white matter connectivity and dynamic patterns of neural activity in the human brain. We examine the relationship between the structural properties of white matter streamlines (structural connectivity) and the functional properties of correlations in neural activity (functional connectivity) within 84 healthy human subjects both at rest and during the performance of attention-and memory-demanding tasks. We show that structural properties, including the length, number, and spatial location of white matter streamlines, are indicative of and can be inferred from the strength of resting-state and task-based functional correlations between brain regions. These results, which are both representative of the entire set of subjects and consistently observed within individual subjects, uncover robust links between structural and functional connectivity in the human brain.uman cognitive function is supported by large-scale interactions between different regions of the brain. The anatomical scaffolding that mediates these interactions can be described by a structural connectome that maps the spatial layout of white matter (1). Structural connectivity (SC), defined by the physical properties of these direct anatomical connections, supports the relay of electrical signals between brain regions. Neurophysiological events can similarly be described by a functional connectome that maps coordinated changes in neuronal activity, field potentials, blood flow, or energy consumption (2). Functional connectivity (FC), defined by temporal correlations in such neurophysiological events, reflects the resting-state and task-dependent strengths of correlated activity in different brain regions (3-5). The estimation of structural and functional connectivity from different experimental techniques raises two complementary questions about the quantitative relationships between structural and functional connectomes: (i) to what extent can the resting-state and task-dependent strengths of functional correlations between brain regions be inferred from structural connectomes, and (ii) to what extent can the physical properties of anatomical connections be inferred from functional connectomes?Connectomes, whether examined at the neural or systems level, are networks whose structural properties, such as the length and number of connections, can differentially impact functional properties, such as local or global correlations in temporal dynamics. Whereas the length and density of anatomical connections are thought to impact functional processes such as information segregation and integration (6, 7), the extent to which such relationships are robustly observed in the human brain is not well understood. Previous studies have been limited in scope to specific anatomical connections and brain regions, small sample sizes, and resting-state neural activity (8-13) and have consequently left several fundamental questions unanswered. How do variations in structural features, such a...

Brain structural abnormalities and neurocognitive dysfunction have been observed in individuals with fetal alcohol spectrum disorders (FASDs). Little is known about how white matter integrity is related to these functional and morphological deficits. We used a combination of diffusion tensor and T1-weighted magnetic resonance imaging to evaluate white matter integrity in individuals with FASDs and related these findings to neurocognitive deficits. Seventeen children and adolescents with FASDs were compared with 19 typically developing age-and gender-matched controls. Lower fractional anisotropy (FA) was observed in individuals with FASDs relative to controls in the right lateral temporal lobe and bilaterally in the lateral aspects of the splenium of the corpus callosum. White matter density was also lower in some, but not all regions in which FA was lower. FA abnormalities were confirmed to be in areas of white matter in post hoc region of interest analyses, further supporting that less myelin or disorganized fiber tracts are associated with heavy prenatal alcohol exposure. Significant correlations between performance on a test of visuomotor integration and FA in bilateral splenium, but not temporal regions were observed within the FASD group. Correlations between the visuomotor task and FA within the splenium were not significant within the control group, and were not significant for measures of reading ability. This suggests that this region of white matter is particularly susceptible to damage from prenatal alcohol exposure and that disruption of splenial fibers in this group is associated with poorer visuomotor integration.

BACKGROUND:The COVID-19 pandemic resulted in a statewide stay-at-home (SAH) order in California beginning March 19, 2020, forcing large-scale behavioral changes and taking an emotional and economic toll. The effects of SAH orders on the trauma population remain unknown. We hypothesized an increase in rates of penetrating trauma, gunshot wounds, suicide attempts, and domestic violence in the Southern California trauma population after the SAH order. METHODS:A multicenter retrospective analysis of all trauma patients presenting to 11 American College of Surgeons levels I and II trauma centers spanning seven counties in California was performed. Demographic data, injury characteristics, clinical data, and outcomes were collected. Patients were divided into three groups based on injury date: before SAH from