Article

Functional and Structural Connectivity Between the Perigenual Anterior Cingulate and Amygdala in Bipolar Disorder

Department of Psychiatry, Yale School of Medicine, 300 George Street, Suite 901, New Haven CT 06511, USA.
Biological psychiatry (Impact Factor: 9.47). 06/2009; 66(5):516-21. DOI: 10.1016/j.biopsych.2009.03.023
Source: PubMed

ABSTRACT Abnormalities in the morphology and function of two gray matter structures central to emotional processing, the perigenual anterior cingulate cortex (pACC) and amygdala, have consistently been reported in bipolar disorder (BD). Evidence implicates abnormalities in their connectivity in BD. This study investigates the potential disruptions in pACC-amygdala functional connectivity and associated abnormalities in white matter that provides structural connections between the two brain regions in BD.
Thirty-three individuals with BD and 31 healthy comparison subjects (HC) participated in a scanning session during which functional magnetic resonance imaging (fMRI) during processing of face stimuli and diffusion tensor imaging (DTI) were performed. The strength of pACC-amygdala functional connections was compared between BD and HC groups, and associations between these functional connectivity measures from the fMRI scans and regional fractional anisotropy (FA) from the DTI scans were assessed.
Functional connectivity was decreased between the pACC and amygdala in the BD group compared with HC group, during the processing of fearful and happy faces (p < .005). Moreover, a significant positive association between pACC-amygdala functional coupling and FA in ventrofrontal white matter, including the region of the uncinate fasciculus, was identified (p < .005).
This study provides evidence for abnormalities in pACC-amygdala functional connectivity during emotional processing in BD. The significant association between pACC-amygdala functional connectivity and the structural integrity of white matter that contains pACC-amygdala connections suggest that disruptions in white matter connectivity may contribute to disturbances in the coordinated responses of the pACC and amygdala during emotional processing in BD.

Download full-text

Full-text

Available from: E. Kale Edmiston, Aug 05, 2015
0 Followers
 · 
121 Views
  • Source
    • "However, the extent of white matter pathology in PD, and its impact upon motor and cognitive function, remains uncertain. Diffusion tensor imaging (DTI) is an effective non-invasive tool to investigate pathological changes in the white matter of living neurodegenerative and psychiatric patients (Acosta-Cabronero et al., 2010; Douaud et al., 2011; Kubicki and Shenton, 2009; Peran et al., 2010; Wang et al., 2009). DTI is sensitive to the diffusion of water molecules within neural tissue (Basser et al., 1994). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Diffusion magnetic resonance imaging is increasingly used as a non-invasive method to investigate white matter structure in neurological and neuropsychiatric disease. However, many options are available for the acquisition sequence and analysis method. Here we used Parkinson's disease as a model neurodegenerative disorder to compare imaging protocols and analysis options. We investigated fractional anisotropy and mean diffusivity of white matter in patients and age-matched controls, comparing two datasets acquired with different imaging protocols. One protocol prioritised the number of b value acquisitions, whilst the other prioritised the number of gradient directions. The dataset with more gradient directions was more sensitive to reductions in fractional anisotropy in Parkinson's disease, whilst the dataset with more b values was more sensitive to increases in mean diffusivity. Moreover, the areas of reduced fractional anisotropy were highly similar to areas of increased mean diffusivity in PD patients. Next, we compared two widely used analysis methods: tract-based spatial statistics identified reduced fractional anisotropy and increased mean diffusivity in Parkinson's disease in many of the major white matter tracts in the frontal and parietal lobes. Voxel-based analyses were less sensitive, with similar patterns of white matter pathology observed only at liberal statistical thresholds. We also used tract-based spatial statistics to identify correlations between a test of executive function (phonemic fluency), fractional anisotropy and mean diffusivity in prefrontal white matter in both Parkinson's disease patients and controls. These findings suggest that in Parkinson's disease there is widespread pathology of cerebral white matter, and furthermore, pathological white matter in the frontal lobe may be associated with executive dysfunction. Diffusion imaging protocols that prioritised the number of directions versus the number of b values were differentially sensitive to alternative markers of white matter pathology, such as fractional anisotropy and mean diffusivity.
    NeuroImage 06/2012; 62(3):1675-84. DOI:10.1016/j.neuroimage.2012.06.012 · 6.36 Impact Factor
  • Source
    • "A reduction in fractional anisotropy is indicative of loss of white matter integrity, and has been found to be correlated with inter-regional functional connectivity. For example, deficits in functional prefrontal-amygdala connectivity in bipolar patients are correlated with reduced fractional anisotropy in the uncinate fasciculus [157], the principal white matter axonal bundle connecting prefrontal regions with anterior temporal lobe structures [158] [159] [160]. While the relationship between DHA status and DTI measures of white matter integrity are not known, a preliminary DTI study (n¼12) observed a positive correlation between total plasma polyunsaturated fatty acid concentrations and fractional anisotropy in the uncinate fasciculus white matter tract in medicated psychotic patients [161] "
    [Show abstract] [Hide abstract]
    ABSTRACT: Animal studies have found that deficits in brain docosahexaenoic acid (DHA, 22:6n-3) accrual during perinatal development leads to transient and enduring abnormalities in brain development and function. Determining the relevance of this evidence to brain disorders in humans has been hampered by an inability to determine antimortem brain DHA levels and limitations associated with a postmortem approach. Accordingly, there is a need for alternate or complementary approaches to better understand the role of DHA in cortical function and pathology, and conventional magnetic resonance imaging (MRI) techniques may be ideally suited for this application. A major advantage of neuroimaging is that it permits prospective evaluation of the effects of manipulating DHA status on both clinical and neuroimaging variables. Emerging evidence from MRI studies suggest that greater DHA status is associated with cortical structural and functional integrity, and suggest that reduced DHA status and abnormalities in cortical function observed in psychiatric disorders may be interrelated phenomenon. Preliminary evidence from animal MRI studies support a critical role of DHA in normal brain development. Neuroimaging research in both human and animals therefore holds tremendous promise for developing a better understanding of the role of DHA status in cortical function, as well as for elucidating the impact of DHA deficiency on neuropathological processes implicated in the etiology and progression of neurodevelopmental and psychiatric disorders.
    Prostaglandins Leukotrienes and Essential Fatty Acids 04/2012; 88(1). DOI:10.1016/j.plefa.2012.03.011 · 1.98 Impact Factor
  • Source
    • "Asato et al. (2010), reviewed here, indicate that it is one of the white matter tracts that reaches maturation earlier in girls than boys. Moreover, several studies have documented abnormalities in the microstructure of the uncinate fasciculus in individuals diagnosed with an affective disorder (Cullen et al., 2010; Versace et al., 2008; Wang et al., 2009) and more recently, in youth at high familial risk for affective disorders (Huang et al., 2011) (Figure 3). "
    [Show abstract] [Hide abstract]
    ABSTRACT: There have been rapid advances in understanding a broad range of changes in brain structure and function during adolescence, and a growing interest in identifying which of these neurodevelopmental changes are directly linked with pubertal maturation—at least in part because of their potential to provide insights into the numerous emotional and behavioral health problems that emerge during this developmental period. This review focuses on what is known about the influence of puberty on white matter development in adolescence.We focus on white matter because of its role in providing the structural architectural organization of the brain and as a structural correlate of communication within complex neural systems. We begin with a review of studies that report sex differences or sex by age interactions in white matter development as these findings can provide, although indirectly,information relevant to puberty-related changes. Studies are also critically reviewed based on methodological procedures used to assess pubertal maturation and relations with white matter changes. Findings are discussed in light of their implications for the development of neural systems underlying the regulation of emotion and behavior and how alterations in the development of these systems may mediate risk for affective disorders in vulnerable adolescents.
    01/2012; 2(1):36-54. DOI:10.1016/j.dcn.2011.06.002
Show more