scholarly journals The Neuroscience of Drug Reward and Addiction

2019 ◽  
Vol 99 (4) ◽  
pp. 2115-2140 ◽  
Author(s):  
Nora D. Volkow ◽  
Michael Michaelides ◽  
Ruben Baler
Keyword(s):  
Drug Exposure ◽  
Self Regulation ◽  
Drug Consumption ◽  
Anterior Cingulate ◽  
Emotional States ◽  
Drug Cues ◽  
Prefrontal Cortical ◽  
The Difference ◽  
Dopamine Signaling ◽  
Cortical Regions

Drug consumption is driven by a drug’s pharmacological effects, which are experienced as rewarding, and is influenced by genetic, developmental, and psychosocial factors that mediate drug accessibility, norms, and social support systems or lack thereof. The reinforcing effects of drugs mostly depend on dopamine signaling in the nucleus accumbens, and chronic drug exposure triggers glutamatergic-mediated neuroadaptations in dopamine striato-thalamo-cortical (predominantly in prefrontal cortical regions including orbitofrontal cortex and anterior cingulate cortex) and limbic pathways (amygdala and hippocampus) that, in vulnerable individuals, can result in addiction. In parallel, changes in the extended amygdala result in negative emotional states that perpetuate drug taking as an attempt to temporarily alleviate them. Counterintuitively, in the addicted person, the actual drug consumption is associated with an attenuated dopamine increase in brain reward regions, which might contribute to drug-taking behavior to compensate for the difference between the magnitude of the expected reward triggered by the conditioning to drug cues and the actual experience of it. Combined, these effects result in an enhanced motivation to “seek the drug” (energized by dopamine increases triggered by drug cues) and an impaired prefrontal top-down self-regulation that favors compulsive drug-taking against the backdrop of negative emotionality and an enhanced interoceptive awareness of “drug hunger.” Treatment interventions intended to reverse these neuroadaptations show promise as therapeutic approaches for addiction.

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 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 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.

Magnetic resonance imaging markers of suicide attempt and suicide risk in adolescents

CNS Spectrums ◽  
2015 ◽  
Vol 20 (4) ◽  
pp. 355-358 ◽  
Author(s):  
Petra C. Martin ◽  
Thomas J. Zimmer ◽  
Lisa A. Pan
Keyword(s):  
Suicide Attempt ◽  
Psychosocial Development ◽  
Functional Neuroimaging ◽  
Gray Matter Volume ◽  
The United States ◽  
Anterior Cingulate ◽  
Prefrontal Cortical ◽  
History Of ◽  
Brain Changes ◽  
Cortical Regions

More than 36,000 people in the United States die from suicide annually, and suicide is the third leading cause of death in adolescence. Adolescence is a time of high risk for suicidal behavior, as well as a time that intervention and treatment may have the greatest impact because of structural brain changes and significant psychosocial development during this period. Functional and structural neuroimaging studies in adults who have attempted suicide suggest distinct gray matter volume abnormalities in cortical regions, as well as prefrontal cortical and dorsal anterior cingulate gyrus neural circuitry differences compared with affective and healthy adult controls. Recent functional neuroimaging studies in adolescents with a history of suicide attempt suggest differences in the attention and salience networks compared with adolescents with depression and no history of suicide attempt and healthy controls when viewing angry faces. In contrast, no abnormalities are seen in these areas in the absence of emotional stimuli. These networks may represent promising targets for future neuroimaging studies to identify markers of risk for future suicide attempt in adolescents.

Central Nervous System Processing of Emotions in Children with Fecal Incontinence and Constipation

2019 ◽  
Vol 47 (1) ◽  
pp. 67-71
Author(s):  
Monika Equit ◽  
Justine Niemczyk ◽  
Anna Kluth ◽  
Carla Thomas ◽  
Mathias Rubly ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Fecal Incontinence ◽  
Event Related Potentials ◽  
Anterior Cingulate ◽  
Afferent Pathways ◽  
Study Results ◽  
Related Potentials ◽  
The Central Nervous System ◽  
Cortical Regions

Abstract. Objective: Fecal incontinence and constipation are common disorders in childhood. The enteric nervous system and the central nervous system are highly interactive along the brain-gut axis. The interaction is mainly afferent. These afferent pathways include centers that are involved in the central nervous processing of emotions as the mid/posterior insula and the anterior cingulate cortex. A previous study revealed altered processing of emotions in children with fecal incontinence. The present study replicates these results. Methods: In order to analyze the processing of emotions, we compared the event-related potentials of 25 children with fecal incontinence and constipation to those of 15 control children during the presentation of positive, negative, and neutral pictures. Results: Children with fecal incontinence and constipation showed altered processing of emotions, especially in the parietal and central cortical regions. Conclusions: The main study results of the previous study were replicated, increasing the certainty and validity of the findings.

scholarly journals Chronic Pain is Associated With Reduced Sympathetic Nervous System Reactivity During Simple and Complex Walking Tasks: Potential Cerebral Mechanisms

2021 ◽  
Vol 5 ◽  
pp. 247054702110302
Author(s):  
Taylor D. Yeater ◽  
David J. Clark ◽  
Lorraine Hoyos ◽  
Pedro A. Valdes-Hernandez ◽  
Julio A. Peraza ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Anterior Cingulate Cortex ◽  
Gray Matter ◽  
Dual Task ◽  
Brain Region ◽  
Skin Conductance Level ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Autonomic Responses ◽  
The Difference

Background Autonomic dysregulation may lead to blunted sympathetic reactivity in chronic pain states. Autonomic responses are controlled by the central autonomic network (CAN). Little research has examined sympathetic reactivity and associations with brain CAN structures in the presence of chronic pain; thus, the present study aims to investigate how chronic pain influences sympathetic reactivity and associations with CAN brain region volumes. Methods Sympathetic reactivity was measured as change in skin conductance level (ΔSCL) between a resting reference period and walking periods for typical and complex walking tasks (obstacle and dual-task). Participants included 31 people with (n = 19) and without (n = 12) chronic musculoskeletal pain. Structural 3 T MRI was used to determine gray matter volume associations with ΔSCL in regions of the CAN (i.e., brainstem, amygdala, insula, and anterior cingulate cortex). Results ΔSCL varied across walking tasks (main effect p = 0.036), with lower ΔSCL in chronic pain participants compared to controls across trials 2 and 3 under the obstacle walking condition. ΔSCL during typical walking was associated with multiple CAN gray matter volumes, including brainstem, bilateral insula, amygdala, and right caudal anterior cingulate cortex (p’s < 0.05). The difference in ΔSCL from typical-to-obstacle walking were associated with volumes of the midbrain segment of the brainstem and anterior segment of the circular sulcus of the insula (p’s < 0.05), with no other significant associations. The difference in ΔSCL from typical-to-dual task walking was associated with the bilateral caudal anterior cingulate cortex, and left rostral cingulate cortex (p’s < 0.05). Conclusions Sympathetic reactivity is blunted during typical and complex walking tasks in persons with chronic pain. Additionally, blunted sympathetic reactivity is associated with CAN brain structure, with direction of association dependent on brain region. These results support the idea that chronic pain may negatively impact typical autonomic responses needed for walking performance via its potential impact on the brain.

Neurocognitive underpinnings of social development during childhood

2021 ◽  
Author(s):  
Nikolaus Steinbeis
Keyword(s):  
Social Control ◽  
Social Development ◽  
Middle Childhood ◽  
Behavioral Control ◽  
Control Mechanisms ◽  
Social Phenomena ◽  
Prefrontal Cortical ◽  
Regulatory Processes ◽  
Subcortical Regions ◽  
Cortical Regions

This chapter reviews the neurocognitive mechanisms underlying social development during middle childhood. The author focuses on social abilities (e.g., theory of mind and empathy) and prosocial behavior (e.g., sharing and helping). The chapter discusses studies and theories on developmental changes in these social phenomena and references evidence of neurocognitive underpinnings where available. The author argues that changes in social development during childhood can best be explained in developments in regulatory processes, such as behavioral control, emotion regulation, conflict processing, and self-other control. The author refers to this cluster of functions as social control mechanisms. Changes in these social control mechanisms are driven by the maturation of neural circuitry comprising prefrontal cortical regions and their interactions with subcortical regions. Crucially, while the neurocognitive mechanisms underlying social development are distinct for different abilities and behaviors, it appears to be domain-general processes that predominantly shape social development during middle childhood.

scholarly journals 'To do or not to do'? The neurobiology of decision-making in daily life: I. Getting the basics

2007 ◽  
Vol 1 (1) ◽  
pp. 10-17 ◽  
Author(s):  
André Palmini ◽  
Victor Geraldi Haase
Keyword(s):  
Decision Making ◽  
Everyday Life ◽  
Theory And Practice ◽  
Moral Issues ◽  
Temporal Perspective ◽  
Prefrontal Cortical ◽  
Cortical Regions

Abstract The constant conflict between decisions leading to immediate pleasurable consequences versus behaviors aiming at long-term social advantages is reviewed here in the framework of the evolutionary systems regulating behavior. The inescapable temporal perspective in decision-making in everyday life is highlighted and integrated with the role of the executive functions in the modulation of subcortical systems. In particular, the representations of the 'non-existent' future in the prefrontal cortical regions and how these representations can bridge theory and practice in everyday life are addressed. Relevant discussions regarding the battle between emotions and reasons in the determination of more complex decisions in the realm of neuroeconomics and in moral issues have been reserved for a second essay.

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