scholarly journals The Fragile Brain: Stress Vulnerability, Negative Affect and GABAergic Neurocircuits in Psychosis

2019 ◽  
Vol 45 (6) ◽  
pp. 1170-1183 ◽  
Author(s):  
Stephan F Taylor ◽  
Tyler B Grove ◽  
Vicki L Ellingrod ◽  
Ivy F Tso
Keyword(s):  
Prefrontal Cortex ◽  
Negative Affect ◽  
Anterior Cingulate ◽  
Gamma Aminobutyric Acid ◽  
Dorsal Anterior Cingulate Cortex ◽  
Stress Vulnerability ◽  
Neuroimaging Data ◽  
Cortical Regions ◽  
Persons With Schizophrenia ◽  
Gaba Function

Abstract Persons with schizophrenia exhibit sensitivity to stress and negative affect (NA), both strongly correlated with poor functional outcome. This theoretical review suggests that NA reflects a “fragile brain,” ie, vulnerable to stress, including events not experienced as stressful by healthy individuals. Based on postmortem evidence of altered gamma-aminobutyric acid (GABA) function in parvalbumin positive interneurons (PVI), animal models of PVI abnormalities and neuroimaging data with GABAergic challenge, it is suggested that GABAergic disruptions weaken cortical regions, which leads to stress vulnerability and excessive NA. Neurocircuits that respond to stressful and salient environmental stimuli, such as the hypothalamic-pituitary-adrenal axis and the amygdala, are highly dysregulated in schizophrenia, exhibiting hypo- and hyper-activity. PVI abnormalities in lateral prefrontal cortex and hippocampus have been hypothesized to affect cognitive function and positive symptoms, respectively; in the medial frontal cortex (dorsal anterior cingulate cortex and dorsal medial prefrontal cortex), these abnormalities may lead to vulnerability to stress, NA and dysregulation of stress responsive systems. Given that postmortem PVI disruptions have been identified in other conditions, such as bipolar disorder and autism, stress vulnerability may reflect a transdiagnostic dimension of psychopathology.

scholarly journals The Role of Primate Prefrontal Cortex in Bias and Shift Between Visual Dimensions

2019 ◽  
Vol 30 (1) ◽  
pp. 85-99 ◽  
Author(s):  
Farshad A Mansouri ◽  
Mark J Buckley ◽  
Daniel J Fehring ◽  
Keiji Tanaka
Keyword(s):  
Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Top Down ◽  
Attentional Processes ◽  
Prefrontal Cortical ◽  
Frontopolar Cortex ◽  
Dorsolateral Prefrontal ◽  
Cortical Regions ◽  
Visual Cortical ◽  
Bilateral Lesions

Abstract Imaging and neural activity recording studies have shown activation in the primate prefrontal cortex when shifting attention between visual dimensions is necessary to achieve goals. A fundamental unanswered question is whether representations of these dimensions emerge from top-down attentional processes mediated by prefrontal regions or from bottom-up processes within visual cortical regions. We hypothesized a causative link between prefrontal cortical regions and dimension-based behavior. In large cohorts of humans and macaque monkeys, performing the same attention shifting task, we found that both species successfully shifted between visual dimensions, but both species also showed a significant behavioral advantage/bias to a particular dimension; however, these biases were in opposite directions in humans (bias to color) versus monkeys (bias to shape). Monkeys’ bias remained after selective bilateral lesions within the anterior cingulate cortex (ACC), frontopolar cortex, dorsolateral prefrontal cortex (DLPFC), orbitofrontal cortex (OFC), or superior, lateral prefrontal cortex. However, lesions within certain regions (ACC, DLPFC, or OFC) impaired monkeys’ ability to shift between these dimensions. We conclude that goal-directed processing of a particular dimension for the executive control of behavior depends on the integrity of prefrontal cortex; however, representation of competing dimensions and bias toward them does not depend on top-down prefrontal-mediated processes.

scholarly journals Dissociable roles of cortical excitation-inhibition balance during patch-leaving versus value-guided decisions

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Luca F. Kaiser ◽  
Theo O. J. Gruendler ◽  
Oliver Speck ◽  
Lennart Luettgau ◽  
Gerhard Jocham
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Neuronal Activity ◽  
Ventromedial Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Mutual Inhibition ◽  
Dorsal Anterior Cingulate Cortex ◽  
Cortical Excitation ◽  
The Cost

AbstractIn a dynamic world, it is essential to decide when to leave an exploited resource. Such patch-leaving decisions involve balancing the cost of moving against the gain expected from the alternative patch. This contrasts with value-guided decisions that typically involve maximizing reward by selecting the current best option. Patterns of neuronal activity pertaining to patch-leaving decisions have been reported in dorsal anterior cingulate cortex (dACC), whereas competition via mutual inhibition in ventromedial prefrontal cortex (vmPFC) is thought to underlie value-guided choice. Here, we show that the balance between cortical excitation and inhibition (E/I balance), measured by the ratio of GABA and glutamate concentrations, plays a dissociable role for the two kinds of decisions. Patch-leaving decision behaviour relates to E/I balance in dACC. In contrast, value-guided decision-making relates to E/I balance in vmPFC. These results support mechanistic accounts of value-guided choice and provide evidence for a role of dACC E/I balance in patch-leaving decisions.

scholarly journals Neural mechanisms of self-affirmation’s stress buffering effects

2020 ◽  
Vol 15 (10) ◽  
pp. 1086-1096 ◽  
Author(s):  
Janine M Dutcher ◽  
Naomi I Eisenberger ◽  
Hayoung Woo ◽  
William M P Klein ◽  
Peter R Harris ◽  
...  
Keyword(s):  
Stress Responses ◽  
Neural Mechanisms ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Stress Buffering ◽  
Prefrontal Cortical ◽  
Stress Task ◽  
Within Subjects ◽  
Improved Performance ◽  
Cortical Regions

Abstract Self-affirmation can buffer stress responses across different contexts, yet the neural mechanisms for these effects are unknown. Self-affirmation has been shown to increase activity in reward-related neural regions, including the ventral striatum and ventromedial prefrontal cortex (VMPFC). Given that reward-related prefrontal cortical regions such as the VMPFC are involved in reducing neurobiological and behavioral responses to stress, we hypothesized that self-affirmation would activate VMPFC and also reduce neural responses to stress in key neural threat system regions such as the dorsal anterior cingulate cortex (dACC) and anterior insula (AI). We explored this hypothesis using self-affirmation and evaluative stress tasks following a within-subjects design in the fMRI scanner. Consistent with prior work, self-affirmation blocks led to lower self-reported stress and improved performance. With respect to neural activity, compared to control blocks, self-affirmation blocks led to greater VMPFC activity, and subsequently less left AI (but not dACC) activity during stress task blocks. Functional connectivity analyses revealed greater connectivity between the VMPFC and left and right AI during self-affirmation compared to control. These findings begin to articulate the neural circuits involved in self-affirmation’s effects during exposure to stressors, and more broadly specify neural reward-based responses to stressful situations.

scholarly journals Shared neural representations of cognitive conflict and negative affect in the medial frontal cortex

2019 ◽  
Author(s):  
Luc Vermeylen ◽  
David Wisniewski ◽  
Carlos González-García ◽  
Vincent Hoofs ◽  
Wim Notebaert ◽  
...  
Keyword(s):  
Negative Affect ◽  
Frontal Cortex ◽  
Supplementary Motor Area ◽  
Cognitive Conflict ◽  
Medial Frontal Cortex ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Neural Representations ◽  
Fmri Study ◽  
Multivariate Pattern

AbstractInfluential theories of medial frontal cortex (MFC) function suggest that the MFC registers cognitive conflict as an aversive signal, but no study directly tested this idea. Instead, recent studies suggested that non-overlapping regions in the MFC process conflict and affect. In this pre-registered human fMRI study, we used multivariate pattern analyses to identify which regions respond similarly to conflict and aversive signals. The results reveal that, of all conflict- and value-related regions, the ventral pre-supplementary motor area (or dorsal anterior cingulate cortex) showed a shared neural pattern response to different conflict and affect tasks. These findings challenge recent conclusions that conflict and affect are processed independently, and provide support for integrative views of MFC function.

scholarly journals Distinguishing neural correlates of context-dependent advantageous- and disadvantageous-inequity aversion

2018 ◽  
Vol 115 (33) ◽  
pp. E7680-E7689 ◽  
Author(s):  
Xiaoxue Gao ◽  
Hongbo Yu ◽  
Ignacio Sáez ◽  
Philip R. Blue ◽  
Lusha Zhu ◽  
...  
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Computational Models ◽  
Social Contexts ◽  
Inequity Aversion ◽  
Context Dependency ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Decision Making Processes ◽  
Context Dependent

Humans can integrate social contextual information into decision-making processes to adjust their responses toward inequity. This context dependency emerges when individuals receive more (i.e., advantageous inequity) or less (i.e., disadvantageous inequity) than others. However, it is not clear whether context-dependent processing of advantageous and disadvantageous inequity involves differential neurocognitive mechanisms. Here, we used fMRI to address this question by combining an interactive game that modulates social contexts (e.g., interpersonal guilt) with computational models that enable us to characterize individual weights on inequity aversion. In each round, the participant played a dot estimation task with an anonymous coplayer. The coplayer would receive pain stimulation with 50% probability when either of them responded incorrectly. At the end of each round, the participant completed a variant of dictator game, which determined payoffs for him/herself and the coplayer. Computational modeling demonstrated the context dependency of inequity aversion: when causing pain to the coplayer (i.e., guilt context), participants cared more about the advantageous inequity and became more tolerant of the disadvantageous inequity, compared with other conditions. Consistently, neuroimaging results suggested the two types of inequity were associated with differential neurocognitive substrates. While the context-dependent processing of advantageous inequity was associated with social- and mentalizing-related processes, involving left anterior insula, right dorsolateral prefrontal cortex, and dorsomedial prefrontal cortex, the context-dependent processing of disadvantageous inequity was primarily associated with emotion- and conflict-related processes, involving left posterior insula, right amygdala, and dorsal anterior cingulate cortex. These results extend our understanding of decision-making processes related to inequity aversion.

scholarly journals Neural mechanisms of economic commitment in the human medial prefrontal cortex

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Konstantinos Tsetsos ◽  
Valentin Wyart ◽  
S Paul Shorkey ◽  
Christopher Summerfield
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Neural Mechanisms ◽  
Anterior Cingulate ◽  
Dorsal Anterior Cingulate Cortex ◽  
Financial Return ◽  
Economic Decisions ◽  
Decision Biases ◽  
Stimulus Value ◽  
Over Time

Neurobiologists have studied decisions by offering successive, independent choices between goods or gambles. However, choices often have lasting consequences, as when investing in a house or choosing a partner. Here, humans decided whether to commit (by acceptance or rejection) to prospects that provided sustained financial return. BOLD signals in the rostral medial prefrontal cortex (rmPFC) encoded stimulus value only when acceptance or rejection was deferred into the future, suggesting a role in integrating value signals over time. By contrast, the dorsal anterior cingulate cortex (dACC) encoded stimulus value only when participants rejected (or deferred accepting) a prospect. dACC BOLD signals reflected two decision biases–to defer commitments to later, and to weight potential losses more heavily than gains–that (paradoxically) maximised reward in this task. These findings offer fresh insights into the pressures that shape economic decisions, and the computation of value in the medial prefrontal cortex.

Neurocircuitry Underlying OCD

2017 ◽  
Author(s):  
Suzanne N. Haber
Keyword(s):  
Prefrontal Cortex ◽  
Orbitofrontal Cortex ◽  
Treatment Strategies ◽  
Reward Processing ◽  
Ventromedial Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Reward Learning ◽  
Imaging Studies ◽  
Dorsal Anterior Cingulate Cortex ◽  
Individual Level

Structural and functional imaging studies have identified abnormalities in the brains of individuals with OCD. The most consistent findings point to pathology in the circuitry connecting the prefrontal cortex with the basal ganglia, and especially to abnormalities in the orbitofrontal cortex (OFC), ventromedial prefrontal cortex (vmPFC), dorsal anterior cingulate cortex (dACC), and striatum. This chapter describes the detailed anatomy and interconnectivity of these structures, together with its functional correlates, to provide context for the more detailed treatment of abnormalities seen in OCD provided in the chapters that follow. These corticostriatal circuits are critical for reward processing, reward learning, and action selection, and so disruption in these circuitries in OCD may underlie abnormalities in these domains. Precisely defining the anatomy of these circuits and how it is disrupted in OCD, at both the group and individual level, is increasingly important, as it may help us to optimize anatomically targeted treatment strategies.

scholarly journals Neurobiology of apathy in Alzheimer's disease

2008 ◽  
Vol 66 (2b) ◽  
pp. 436-443 ◽  
Author(s):  
Henrique Cerqueira Guimarães ◽  
Richard Levy ◽  
Antônio Lúcio Teixeira ◽  
Rogério Gomes Beato ◽  
Paulo Caramelli
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Decision Making ◽  
Prefrontal Cortex ◽  
Review Article ◽  
Anterior Cingulate ◽  
Combining Data ◽  
Neuroimaging Data ◽  
Pathophysiological Model

Apathy is considered the most frequent neuropsychiatric disturbance in dementia and its outcome is generally deleterious. Apathy can be related to a dysfunction of the anatomical-system that supports the generation of voluntary actions, namely the prefrontal cortex and/or the prefrontal-subcortical circuits. In Alzheimer's disease, pathological and neuroimaging data indicate that apathy is likely due to a dysfunction of the medial prefrontal cortex. Accordingly, in this review article, we propose a pathophysiological model to explain apathetic behavior in Alzheimer's disease, combining data from neuroimaging, neuropathology and experimental research on the role of orbito-frontal cortex, anterior cingulate cortex, basal ganglia and dopamine in decision-making neurobiology.

scholarly journals Reduced ribosomal DNA transcription in the prefrontal cortex of suicide victims: consistence of new molecular RT-qPCR findings with previous morphometric data from AgNOR-stained pyramidal neurons

2021 ◽  
Author(s):  
Marta Krzyżanowska ◽  
Krzysztof Rębała ◽  
Johann Steiner ◽  
Michał Kaliszan ◽  
Dorota Pieśniak ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Ribosomal Dna ◽  
Pyramidal Neurons ◽  
Quantitative Polymerase Chain Reaction ◽  
Anterior Cingulate ◽  
Rdna Transcription ◽  
Relative Level ◽  
Prefrontal Cortical ◽  
Dorsolateral Cortex ◽  
Cortical Regions

AbstractPrefrontal cortical regions play a key role in behavioural regulation, which is profoundly disturbed in suicide. The study was carried out on frozen cortical samples from the anterior cingulate cortex (dorsal and ventral parts, ACd and ACv), the orbitofrontal cortex (OFC), and the dorsolateral cortex (DLC) obtained from 20 suicide completers (predominantly violent) with unknown psychiatric diagnosis and 21 non-suicidal controls. The relative level of ribosomal RNA (rRNA) as a marker of the transcriptional activity of ribosomal DNA (rDNA) was evaluated bilaterally in prefrontal regions mentioned above (i.e. in eight regions of interest, ROIs) by reverse transcription and quantitative polymerase chain reaction (RT-qPCR). The overall statistical analysis revealed a decrease in rDNA activity in suicide victims versus controls, particularly in male subjects. Further ROI-specific post hoc analyses revealed a significant decrease in this activity in suicides compared to non-suicides in five ROIs. This effect was accentuated in the ACv, where it was observed bilaterally. Our findings suggest that decreased rDNA transcription in the prefrontal cortex plays an important role in suicide pathogenesis and corresponds with our previous morphometric analyses of AgNOR-stained neurons.

Sign in / Sign up

Export Citation Format

Share Document