Abstract
BackgroundNeuroimaging studies in late life depression have reported decreased structural integrity of white matter tracts in the prefrontal cortex. Functional studies have identified changes in functional connectivity among several key areas involved in mood regulation. Few studies have combined structural and functional imaging. In this study we sought to examine the relationship between the uncinate fasciculus, a key fronto-temporal tract and resting state functional connectivity between the ventral prefrontal cortex ((PFC) and limbic and striatal areas.MethodsThe sample consisted of 24 older patients remitted from unipolar major depression. Each participant had a magnetic resonance imaging brain scan using standardized protocols to obtain both diffusion tensor imaging and resting state functional connectivity data. Our statistical approach compared structural integrity of the uncinate fasciculus and functional connectivity data.ResultsWe found positive correlations between left uncinate fasciculus (UF) fractional anisotropy (FA) and resting state functional connectivity (rsFC) between the left ventrolateral PFC and left amygdala and between the left ventrolateral PFC and the left hippocampus. In addition, we found a significant negative correlation between left ventromedial PFC-caudate rsFC and left UF FA. The right UF FA did not correlate with any of the seed region based connectivity.ConclusionsThese results support the notion that resting state functional connectivity reflects structural integrity, since the ventral PFC is structurally connected to temporal regions by the UF. Future studies should include larger samples of patients and healthy comparison subjects in which both resting state and task-based functional connectivity are examined.
Highlights
Studies over the past decade have improved our understanding of the neural circuits underlying mood and the development of depression
Phillips et al [2] presented models of emotion regulation in mood disorders that implicate the lateral prefrontal cortex (PFC) and the medial PFC in regulation of emotion perceptual processes in amygdala and ventral striatum
There are no current published studies combining diffusion tensor imaging (DTI) and functional magnetic resonance imaging (fMRI) in late life depression (LLD), one recent study examining key brain regions involved in mood and mood disorders has concluded that functional connectivity reflects structural connectivity in these areas [3]
Summary
Studies over the past decade have improved our understanding of the neural circuits underlying mood and the development of depression. There are no current published studies combining DTI and fMRI in late life depression (LLD), one recent study examining key brain regions involved in mood and mood disorders has concluded that functional connectivity reflects structural connectivity in these areas [3]. We sought to use both DTI and fMRI to examine the relationship between structural integrity of PFC white matter and functional connectivity between frontal and limbic regions among older depressed patients. Neuroimaging studies in late life depression have reported decreased structural integrity of white matter tracts in the prefrontal cortex. In this study we sought to examine the relationship between the uncinate fasciculus, a key fronto-temporal tract and resting state functional connectivity between the ventral prefrontal cortex ((PFC) and limbic and striatal areas
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
