Amygdala and Ventromedial Prefrontal Cortex Are Inversely Coupled During Regulation of Negative Affect and Predict the Diurnal Pattern of Cortisol Secretion Among Older Adults

ArticleinThe Journal of Neuroscience : The Official Journal of the Society for Neuroscience 26(16):4415-25 · May 2006with28 Reads
DOI: 10.1523/JNEUROSCI.3215-05.2006 · Source: PubMed
Abstract
Among younger adults, the ability to willfully regulate negative affect, enabling effective responses to stressful experiences, engages regions of prefrontal cortex (PFC) and the amygdala. Because regions of PFC and the amygdala are known to influence the hypothalamic-pituitary-adrenal axis, here we test whether PFC and amygdala responses during emotion regulation predict the diurnal pattern of salivary cortisol secretion. We also test whether PFC and amygdala regions are engaged during emotion regulation in older (62- to 64-year-old) rather than younger individuals. We measured brain activity using functional magnetic resonance imaging as participants regulated (increased or decreased) their affective responses or attended to negative picture stimuli. We also collected saliva samples for 1 week at home for cortisol assay. Consistent with previous work in younger samples, increasing negative affect resulted in ventral lateral, dorsolateral, and dorsomedial regions of PFC and amygdala activation. In contrast to previous work, decreasing negative affect did not produce the predicted robust pattern of higher PFC and lower amygdala activation. Individuals demonstrating the predicted effect (decrease < attend in the amygdala), however, exhibited higher signal in ventromedial prefrontal cortex (VMPFC) for the same contrast. Furthermore, participants displaying higher VMPFC and lower amygdala signal when decreasing compared with the attention control condition evidenced steeper, more normative declines in cortisol over the course of the day. Individual differences yielded the predicted link between brain function while reducing negative affect in the laboratory and diurnal regulation of endocrine activity in the home environment.
    • "By contrast, we found less dmPFC activation in non-PTSD survivors compared to the probable PTSD group. Decreased mPFC activity has been reported when subjects suppress negative emotions [44] . Less activation in the acute posttraumatic period in non-PTSD survivors compared to the probable PTSD group may reflect successful suppression of negative emotional responses, whereas greater activation in the probable PTSD survivors may reflect failure of suppression of negative emotional responses and subsequent recruitment of other regulatory strategies like appraisal. "
    [Show abstract] [Hide abstract] ABSTRACT: Accumulating evidence suggests traumatic experience can rapidly alter brain activation associated with emotion processing. However, little is known about acute changes in emotion neurocircuits that underlie PTSD symptom development. To examine acute alterations in emotion circuit activation and structure that may be linked to PTSD symptoms, thirty-eight subjects performed a task of appraisal of emotional faces as their brains were functionally and structurally studied with MRI at both two weeks and three months after motor vehicle collision (MVC). As determined by symptoms reported in the PTSD Checklist at three months, sixteen survivors developed probable PTSD, whereas the remaining 22 did not meet criteria for PTSD diagnosis (non-PTSD). The probable PTSD group had greater activation than the non-PTSD group in dorsal and ventral medial prefrontal cortex (dmPFC and vmPFC) while appraising fearful faces within two weeks after MVC and in left insular cortex (IC) three months after MVC. dmPFC activation at two weeks significantly positively correlated with PTSD symptom severity at two weeks (R = 0.462, P = 0.006) and three months (R = 0.418, p = 0.012). Changes over time in dmPFC activation and in PTSD symptom severity were also significantly positively correlated in the probable PTSD group (R = 0.641, P = 0.018). A significant time by group interaction was found for volume changes in left superior frontal gyrus (SFG, F = 6.048, p = 0.019) that partially overlapped dmPFC active region. Between two weeks and three months, left SFG volume decreased in probable PTSD survivors. These findings identify alterations in frontal cortical activity and structure during the early post-trauma period that appear to be associated with development of PTSD symptoms.
    Full-text · Article · Jul 2016
    • "Here we found abnormal responses within this system. An increase in vmPFC activity and decrease in amygdala activity is a typical pattern of hemodynamic response during emotional down regulation (Cunningham et al. 2004; Johnstone et al. 2007; Urry et al. 2006). This may reflect a specific deficit in the emotion regulation element of sociomoral processing; whereas nonstimulant users use a balance of emotional and cognitive resources to make moral decisions, stimulant users may be overly reliant on cognitive systems and downregulate emotional processes when arriving at a judgment. "
    [Show abstract] [Hide abstract] ABSTRACT: Rationale Stimulant use is a significant and prevalent problem, particularly in criminal populations. Previous studies found that cocaine and methamphetamine use is related to impairment in identifying emotions and empathy. Stimulant users also have abnormal neural structure and function of the ventromedial prefrontal cortex (vmPFC), amygdala, and anterior (ACC) and posterior cingulate (PCC), regions implicated in moral decision-making. However, no research has studied the neural correlates of stimulant use and explicit moral processing in an incarcerated population. Objectives Here, we examine how stimulant use affects sociomoral processing that might contribute to antisocial behavior. We predicted that vmPFC, amygdala, PCC, and ACC would show abnormal neural response during a moral processing task in incarcerated methamphetamine and cocaine users. Methods Incarcerated adult males (N = 211) were scanned with a mobile MRI system while completing a moral decision-making task. Lifetime drug use was assessed. Neural responses during moral processing were compared between users and non-users. The relationship between duration of use and neural function was also examined. Results Incarcerated stimulant users showed less amygdala engagement than non-users during moral processing. Duration of stimulant use was negatively associated with activity in ACC and positively associated with vmPFC response during moral processing. Conclusions These results suggest a dynamic pattern of fronto-limbic moral processing related to stimulant use with deficits in both central motive and cognitive integration elements of biological moral processes theory. This increases our understanding of how drug use relates to moral processing in the brain in an ultra-high-risk population.
    Full-text · Article · Jul 2016
    • "In addition, we have shown that mPFC-pons connectivity during a subjective emotional experience task was negatively correlated with depressive symptoms and positively correlated with HRV during the emotion task (Smith et al., 2015). Several studies suggest that in both task-related and resting state studies as well as in trait anxiety the top-down regulation by the PFC of the amygdala is diminished (Kim and Whalen, 2009; Kim et al., 2011a Kim et al., , 2011b Davidson and McEwen, 2012; Urry et al., 2006). Kim et al. (2011a) for example demonstrated negatively correlated amygdala-ventral mPFC functional connectivity at rest in high anxious individuals, in contrast to positively correlated activity in low anxious subjects. "
    [Show abstract] [Hide abstract] ABSTRACT: Based on neurobiological and evolutionary arguments, the generalized unsafety theory of stress (GUTS) hypothesizes that the stress response is a default response, and that chronic stress responses are caused by generalized unsafety (GU), independent of stressors or their cognitive representation. Three highly prevalent conditions are particularly vulnerable to becoming 'compromised' in terms of GU, and carry considerable health risks: Thus, GUTS critically revises and expands stress theory, by focusing on safety instead of threat, and by including risk factors that have hitherto not been attributed to stress.
    Full-text · Article · Jul 2016
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