scholarly journals Brain mechanisms associated with depressive relapse and associated cognitive impairment following acute tryptophan depletion

1999 ◽  
Vol 174 (6) ◽  
pp. 525-529 ◽  
Author(s):  
Katharine A. Smith ◽  
John S. Morris ◽  
Karl J. Fristdn ◽  
Philip J. Cowen ◽  
Raymond J. Dolan
Keyword(s):  
Cognitive Impairment ◽  
Neural Activity ◽  
Cognitive Task ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Acute Tryptophan Depletion ◽  
Control Procedure ◽  
Tryptophan Depletion ◽  
Clinical Relapse ◽  
Verbal Fluency Task

BackgroundAcute tryptophan depletion lowers brain serotonin synthesis and results in a transient, but striking, clinical relapse in recovered depressed patients.AimsTo identify brain regions which change their activity as an acute depressive relapse evolves and to determine how pathological mood might modulate neural activity during a cognitive task.MethodWe used H215O positron-emission tomography (PET) to study eight recovered depressed men after tryptophan depletion and after a control procedure. During both PET scan sessions, subjects performed a paced verbal fluency task which alternated with a control verbal repetition task.ResultsIncreasing levels of depression after tryptophan depletion were associated with diminished neural activity in the ventral anterior cingulate, orbitofrontal cortex and caudate nucleus regions. In addition, depressive relapse attenuated cognitive task-related activation in the anterior cingulate cortex.ConclusionsOur data indicate that changes in neural activity in distinct brain regions mediate the clinical phenomena of depression and depression-related cognitive impairment following acute tryptophan depletion. These changes could be associated with the widespread distribution of serotonin neurons in brain pathways associated with the expression of affect and cognitive performance.

Abstract WMP117: Regional Homogeneity Changes In Patients With Transient Ischemic Attack: A Resting-state Functional Magnetic Resonance Imaging Study

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Jian Guo ◽  
Ning Chen ◽  
Muke Zhou ◽  
Pian Wang ◽  
Li He
Keyword(s):  
Transient Ischemic Attack ◽  
Neural Activity ◽  
Resting State ◽  
Right Hemisphere ◽  
Brain Activity ◽  
Imaging Study ◽  
Brain Regions ◽  
Regional Homogeneity ◽  
Anterior Cingulate ◽  
Ischemic Attack

Background: Transient ischemic attack (TIA) can increase the risk of some neurologic dysfunctions, of which the mechanism remains unclear. Resting-state functional MRI (rfMRI) is suggested to be a valuable tool to study the relation between spontaneous brain activity and behavioral performance. However, little is known about whether the local synchronization of spontaneous neural activity is altered in TIA patients. The purpose of this study is to detect differences in regional spontaneous activities throughout the whole brain between TIAs and normal controls. Methods: Twenty one TIA patients suffered an ischemic event in the right hemisphere and 21 healthy volunteers were enrolled in the study. All subjects were investigated using cognitive tests and rfMRI. The regional homogeneity (ReHo) was calculate and compared between two groups. Then a correlation analysis was performed to explore the relationship between ReHo values of brain regions showing abnormal resting-state properties and clinical variables in TIA group. Results: Compared with controls, TIA patients exhibited decreased ReHo in right dorsolateral prefrontal cortex (DLPFC), right inferior prefrontal gyrus, right ventral anterior cingulate cortex and right dorsal posterior cingular cortex. Moreover, the mean ReHo in right DLPFC and right inferior prefrontal gyrus were significantly correlated with MoCA in TIA patients. Conclusions: Neural activity in the resting state is changed in patients with TIA. The positive correlation between regional homogeneity of rfMRI and cognition suggests that ReHo may be a promising tool to better our understanding of the neurobiological consequences of TIA.

scholarly journals Political uncertainty moderates neural evaluation of incongruent policy positions

2021 ◽  
Vol 376 (1822) ◽  
pp. 20200138 ◽  
Author(s):  
Ingrid J. Haas ◽  
Melissa N. Baker ◽  
Frank J. Gonzalez
Keyword(s):  
Neural Activity ◽  
Political Party ◽  
Party Identification ◽  
Insular Cortex ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Party Affiliation ◽  
Policy Positions ◽  
Political Evaluation ◽  
Neural Underpinnings

Uncertainty has been shown to impact political evaluation, yet the exact mechanisms by which uncertainty affects the minds of citizens remain unclear. This experiment examines the neural underpinnings of uncertainty in political evaluation using functional magnetic resonance imaging (fMRI). During fMRI, participants completed an experimental task where they evaluated policy positions attributed to hypothetical political candidates. Policy positions were either congruent or incongruent with candidates' political party affiliation and presented with varying levels of certainty. Neural activity was modelled as a function of uncertainty and incongruence. Analyses suggest that neural activity in brain regions previously implicated in affective and evaluative processing (anterior cingulate cortex, insular cortex) differed as a function of the interaction between uncertainty and incongruence, such that activation in these areas was greatest when information was both certain and incongruent, and uncertainty influenced processing differently as a function of the valence of the attached information. These findings suggest that individuals are attuned to uncertainty in the stated issue positions of politicians, and that the neural processing of this uncertainty is dependent on congruence of these positions with expectations based on political party identification. Implications for the study of emotion and politics and political cognition are discussed. This article is part of the theme issue ‘The political brain: neurocognitive and computational mechanisms’.

scholarly journals Political Uncertainty Moderates Neural Evaluation of Incongruent Policy Positions

2020 ◽  
Author(s):  
Ingrid Johnsen Haas ◽  
Melissa Baker ◽  
Frank Gonzalez
Keyword(s):  
Neural Activity ◽  
Political Party ◽  
Party Identification ◽  
Insular Cortex ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Party Affiliation ◽  
Policy Positions ◽  
Political Evaluation ◽  
Neural Underpinnings

Uncertainty has been shown to impact political evaluation, yet the exact mechanisms by which uncertainty affects the minds of citizens remain unclear. This experiment examines the neural underpinnings of uncertainty in political evaluation using functional MRI (fMRI). During fMRI, participants completed an experimental task where they evaluated policy positions attributed to hypothetical political candidates. Policy positions were either congruent or incongruent with candidates’ political party affiliation and presented with varying levels of certainty. Neural activity was modeled as a function of uncertainty and incongruence. Analyses suggest that neural activity in brain regions previously implicated in affective and evaluative processing (anterior cingulate cortex, insular cortex) differed as a function of the interaction between uncertainty and incongruence, such that activation in these areas was greatest when information was both certain and incongruent and uncertainty influenced processing differently as a function of the valence of the attached information. These findings suggest that individuals are attuned to uncertainty in the stated issue positions of politicians, and that the neural processing of this uncertainty is dependent on congruence of these positions with expectations based on political party identification. Implications for the study of emotion and politics and political cognition are discussed.

SPET study of verbal fluency in schizophrenia and epilepsy

1998 ◽  
Vol 173 (1) ◽  
pp. 69-74 ◽  
Author(s):  
John D. C. Mellers ◽  
Naoto Adachi ◽  
Noriyoshi Takei ◽  
Alice Cluckie ◽  
Brian K. Toone ◽  
...  
Keyword(s):  
Blood Flow ◽  
Temporal Lobe ◽  
Verbal Fluency ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Verbal Fluency Task ◽  
Temporal Lobes ◽  
Word Repetition ◽  
Fluency Task

BackgroundThe association between temporal lobe epilepsy and schizophrenia suggests that the critical abnormality may be pathology within the temporal lobes. People with schizophrenia-like psychosis of epilepsy (SLPE) provide a useful group in which to examine the importance of temporal and frontal lobe dysfunction in schizophrenia.MethodA verbal fluency activation paradigm and a 99mTc HMPAO SPET were used to study frontotemporal function in people with SLPE (n = 12), schizophrenia (n = 11) and epilepsy (n = 16).ResultsPeople with SLPE differed from both other groups by showing lower blood flow in the left superior temporal gyrus during performance of a verbal fluency task compared with a word repetition task (F=5.4, P=0.01). During the verbal fluency task people with primary schizophrenia showed a greater increase in blood flow in anterior cingulate (F=4.5, P=0.02) than the other two groups. There were no between-group differences in frontal brain regions.ConclusionOur findings support an association between left temporal lobe abnormality and SLPE. The different patterns of activation observed in people with primary schizophrenia and SLPE suggests that different pathophysiological mechanisms may operate in these two groups. In SLPE the pathophysiology may be relatively confined to the dominant temporal lobe.

Neuroticism and Its Associated Brain Activation in Women With PTSD

2016 ◽  
Vol 35 (1-2) ◽  
pp. 341-363
Author(s):  
Nicholas Brown ◽  
Jessica A. Wojtalik ◽  
Melissa Turkel ◽  
Tessa Vuper ◽  
David Strasshofer ◽  
...  
Keyword(s):  
Neural Activity ◽  
Interpersonal Violence ◽  
Neural Correlates ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Control Group ◽  
Stress Model ◽  
Conflict Task ◽  
Increased Risk ◽  
Diathesis Stress Model

Previous research suggests a diathesis-stress model of posttraumatic stress disorder (PTSD), wherein individuals with high levels of neuroticism who are exposed to traumatic events subsequently develop PTSD. Although studies have established relationships between neuroticism and neurological functioning in various brain regions for healthy and depressed individuals, the specific neural correlates of neuroticism for individuals with PTSD are yet unknown. This relationship is particularly relevant for women, given that their increased risk for PTSD is partially accounted for by their higher baseline levels of neuroticism. The current study examined previously established neural correlates of neuroticism in 61 women (48 women with interpersonal violence [IPV]/PTSD and 13 healthy controls). A specific region of interest map, including the amygdala, hippocampus, parahippocampus, anterior cingulate cortex (ACC), and dorsal medial prefrontal cortex (dmPFC), was examined while participants completed an emotional conflict task. Results showed that the PTSD group had significantly higher neuroticism scores than the healthy control group ( t = 6.90, p < .001). Higher neuroticism scores were associated with increased neural activity in the right dmPFC when participants were instructed to directly attend to faces with negative emotional valences. Significant trends between higher neuroticism scores and greater right amygdala and right ACC activation also emerged for this condition. Finally, neuroticism was found to be associated with right amygdala and right parahippocampal activity when participants were instructed to ignore faces with negative emotional valences. The results of this study lend further evidence to the proposed diathesis-stress model of neuroticism and PTSD. Moreover, findings suggest a significant association between neuroticism and neural activity in brain regions associated with fear and emotion regulation for women with IPV and subsequent PTSD.

scholarly journals The Cerebellum Is Related to Cognitive Dysfunction in White Matter Hyperintensities

2021 ◽  
Vol 13 ◽  
Author(s):  
Shanshan Cao ◽  
Jiajia Nie ◽  
Jun Zhang ◽  
Chen Chen ◽  
Xiaojing Wang ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
White Matter ◽  
White Matter Hyperintensities ◽  
Small Vessel Disease ◽  
Gray Matter Volume ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Magnetic Resonance Imaging Mri ◽  
Fazekas Scale ◽  
And Function

ObjectiveWhite matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) is frequently presumed to be secondary to cerebral small vessel disease (CSVD) and associated with cognitive decline. The cerebellum plays a key role in cognition and has dense connections with other brain regions. Thus, the aim of this study was to investigate if cerebellar abnormalities could occur in CSVD patients with WMHs and the possible association with cognitive performances.MethodsA total of 104 right-handed patients with WMHs were divided into the mild WMHs group (n = 39), moderate WMHs group (n = 37), and severe WMHs group (n = 28) according to the Fazekas scale, and 36 healthy controls were matched for sex ratio, age, education years, and acquired resting-state functional MRI. Analysis of voxel-based morphometry of gray matter volume (GMV) and seed-to-whole-brain functional connectivity (FC) was performed from the perspective of the cerebellum, and their correlations with neuropsychological variables were explored.ResultsThe analysis revealed a lower GMV in the bilateral cerebellum lobule VI and decreased FC between the left- and right-sided cerebellar lobule VI with the left anterior cingulate gyri in CSVD patients with WMHs. Both changes in structure and function were correlated with cognitive impairment in patients with WMHs.ConclusionOur study revealed damaged GMV and FC in the cerebellum associated with cognitive impairment. This indicates that the cerebellum may play a key role in the modulation of cognitive function in CSVD patients with WMHs.

scholarly journals Anxiety attenuates learning advantages conferred by statistical stability and induces loss of volatility-attuning in brain activity

2021 ◽  
Author(s):  
Elise G Rowe ◽  
Clare Harris ◽  
Ilvana Dzafic ◽  
Marta Garrido
Keyword(s):  
Neural Activity ◽  
Brain Activity ◽  
Stable Condition ◽  
Superior Temporal Gyrus ◽  
Brain Regions ◽  
Anterior Cingulate ◽  
Environmental Stability ◽  
Statistical Stability ◽  
Behavioural Adaptation ◽  
Threat Of Shock

Anxiety can alter an individual's perception of their external sensory environment. Previous studies suggest that anxiety can increase the magnitude of neural responses to unexpected (or surprising) stimuli. Additionally, surprise responses are reported to be boosted during stable compared to volatile environments. Few studies, however, have examined how learning is impacted by both threat and volatility. To investigate these effects, we used threat-of-shock to transiently increase subjective anxiety in healthy adults during an auditory oddball task, in which the regularity could be stable or volatile, while undergoing functional Magnetic Resonance Imaging (fMRI) scanning. We then used Bayesian Model Selection (BMS) mapping to pinpoint the brain areas where different models of anxiety displayed the highest evidence. Behaviourally, we found that threat-of-shock eliminated the accuracy advantage conferred by environmental stability over volatility in the task at hand. Neurally, we found that threat-of-shock led to both attenuation and loss of volatility-attuning of neural activity evoked by surprising sounds across most subcortical and limbic brain regions including the thalamus, basal ganglia, claustrum, insula, anterior cingulate, hippocampal gyrus and also the superior temporal gyrus. Conversely, within two small clusters in the left medial frontal gyrus and extrastriate area, threat-of-shock boosted the neural activity (relative to the safe and volatile condition) to the levels observed during the safe and stable condition, while also inducing a loss of volatility-attuning. Taken together, our findings suggest that threat eliminates the learning advantage conferred by statistical stability compared to volatility. Thus, we propose that anxiety disrupts behavioural adaptation to environmental statistics, and that multiple subcortical and limbic regions are implicated in this process.

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