Dysregulation among insula, postcentral gyrus, and precuneus and its association with suicide risk
Poster No:
470
Submission Type:
Abstract Submission
Authors:
Yoojin Lee1, Jessica Gilbert1, Carlos Zarate1, Elizabeth Ballard1
Institutions:
1NIMH/NIH, Bethesda, MD
First Author:
Co-Author(s):
Introduction:
Suicide is a serious public health concern in the US, underscoring the need for objective markers of the suicidal behaviors. Research links aggressive impulsivity to suicide(Mann et al., 2003; Gvion et al., 2014), possibly tied to reduced brain function in sensory regulating regions (Lalovic et al., 2022), such as prefrontal cortex, precuneus, and insula (Alacreu-Crespo et al., 2020; Brown et al., 2020; Cao et al., 2015; Dombrovski et al., 2013; Sankar et al., 2022). However, limited knowledge is available on the association between the impulsive aggression, suicidal behavior, and brain regions responsible for the sensory and emotional regulation, specifically when considering the temporal dynamics of the suicidal behavior. This study examines whether trait-like aggression and impulsivity, along with task-oriented impulsivity measures, could moderate resting-state magnetoencephalographic (MEG) power and effective connectivity.
Methods:
Initial recruitment included 121 participants across four groups: recent suicidal crisis (HR; n=14), suicide attempt history excluding the last year (LR; n=41), anxiety/mood disorders without suicidal history (CC; n=38), and no psychiatric/suicidal history (MR; n=28). Impulsivity was assessed through two measurements: trait impulsivity, measured using the Barratt Impulsiveness Scale (BIS), and risk-taking impulsivity, evaluated using the Balloon Analogue Rating Task (BART). Additionally, trait-like aggression was measured using the Buss-Perry Aggression Scale (BPA). Linear mixed effects models probed differences in resting-state MEG power between HR group and LR, CC, and MR groups across delta (2-4Hz), theta (4-8Hz), alpha (9-14Hz), beta (15-29Hz), and gamma (30-58Hz) bands in sensory regulating and decision-making brain regions, such as the prefrontal cortex, precuneus, insula, and post-central gyrus. This study also explored the interactions between the resting-state MEG power and aggressive impulsivity measures in those regions. Dynamic causal modeling (DCM), a generative model that seeks to find hidden neural states from measured brain responses using a Bayesian perspective (Stephan et al., 2010), was used to assess the extrinsic connectivity between sensory/emotion-regulating brain regions. The CMM_NMDA model of DCM was used to assess the fast (α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated) and slow (N-methyl-D-aspartate (NMDA)-mediated) glutamatergic signaling (Moran et al., 2011).
Results:
The HR group did not show the difference in resting-state MEG power, compared to LR, CC, and MR groups. However, HR group with high trait-like aggression or impulsivity scores showed reduced MEG power in regions responsible for sensory/emotion regulation, compared to HR group with low scores. Those regions included the precuneus (delta), supra marginal gyrus (theta), angular gyrus, middle frontal gyrus, inferior frontal gyrus (alpha), precuneus, and inferior frontal gyrus (beta), voxel-based corrected ps<.05. For the gamma band, postcentral gyrus showed a trend-level reduction, voxel-based corrected p=.09. Compared to LR, CC, and MR groups, HR group showed downregulated glutamatergic feedback between the precuneus (PRE) and insula (INS), posterior probability(pp) > .95. High trait-like impulsivity yielded reduced PRE to INS feedback, whereas high risk-taking impulsivity upregulated glutamatergic feedback from INS to the postcentral gyrus (PCG) and between PCG and INS, pps > .95. The results indicate dysregulated glutamatergic connectivity in brain regions related to the sensory regulation, with implications for suicide risk.
Conclusions:
Investigating various impulsivity types and their connection to suicide risk while considering temporal dynamics of suicidal behaviors could be crucial for the suicide research. The study suggests that the glutamatergic-mediated sensory and emotion-regulation processes may serve as significant markers of suicide risk, which can be evaluated in future longitudinal studies.
Disorders of the Nervous System:
Psychiatric (eg. Depression, Anxiety, Schizophrenia) 1
Modeling and Analysis Methods:
EEG/MEG Modeling and Analysis 2
Task-Independent and Resting-State Analysis
Novel Imaging Acquisition Methods:
MEG
Keywords:
ADULTS
Computational Neuroscience
Data analysis
Glutamate
MEG
Psychiatric Disorders
1|2Indicates the priority used for review
·The band-specific oscillating power of the magnetoencephalography (MEG) signals in individuals in the high risk (HR) group with a recent suicidal crisis and varying levels of impulsivity
·Dynamic Causal Modeling (DCM) of the effective connectivity in the high-risk (HR) group compared to the other groups
Provide references using author date format
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Cao, J. (2015) 'Abnormal regional homogeneity in young adult suicide attempters with no diagnosable psychiatric disorder: a resting state functional magnetic imaging study', Psychiatry Research, 231(2), pp. 95-102.
Dombrovski, A. Y. (2013) 'Reward signals, attempted suicide, and impulsivity in late-life depression', JAMA Psychiatry, 70(10), p. 1.
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