scholarly journals 1H MRS Study of Dorsolateral Prefrontal Cortex in Healthy Individuals before and after Lithium Administration

2004 ◽  
Vol 29 (10) ◽  
pp. 1918-1924 ◽  
Author(s):  
Paolo Brambilla ◽  
Jeffrey A Stanley ◽  
Roberto B Sassi ◽  
Mark A Nicoletti ◽  
Alan G Mallinger ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Healthy Individuals ◽  
1H Mrs ◽  
Dorsolateral Prefrontal ◽  
Before And After

scholarly journals Dorsolateral prefrontal cortex GABA deficit in older adults with sleep-disordered breathing

2017 ◽  
Vol 114 (38) ◽  
pp. 10250-10255 ◽  
Author(s):  
Ana C. Pereira ◽  
Xiangling Mao ◽  
Caroline S. Jiang ◽  
Guoxin Kang ◽  
Sara Milrad ◽  
...  
Keyword(s):  
Older Adults ◽  
Prefrontal Cortex ◽  
Cognitive Decline ◽  
Dorsolateral Prefrontal Cortex ◽  
Sleep Disordered Breathing ◽  
Apnea Hypopnea Index ◽  
Resonance Spectroscopy ◽  
1H Mrs ◽  
Dorsolateral Prefrontal ◽  
Disordered Breathing

Sleep-disordered breathing (SDB) is a common disorder in aging that is associated with cognitive decline, including significant executive dysfunction, for which the neurobiological underpinnings remain poorly understood. Using proton magnetic resonance spectroscopy (1H MRS), this study assessed whether dysregulation of the homeostatic balance of the major inhibitory and excitatory amino acid neurotransmitter systems of γ-aminobutyric acid (GABA) and glutamate, respectively, play a role in SDB. Levels of GABA and those of the combined resonances of glutamate and glutamine (Glx), were measured by 1H MRS in the left dorsolateral prefrontal cortex (l-DLPFC) and bilateral hippocampal regions of 19 older adults (age ± SD: 66.1 ± 1.9 years) with moderate to severe SDB, defined as having an Apnea–Hypopnea Index (AHI) greater than 15 as assessed by polysomnography, and in 14 older adults (age ± SD: 62.3 ± 1.3 years) without SDB (AHI < 5). In subjects with SDB, levels of l-DLPFC GABA, but not Glx, were significantly lower than in control subjects (P< 0.0002). Additionally, there was a negative correlation between l-DLPFC GABA levels, but not Glx, and SDB severity by AHI (r= -0.68,P< 0.0001), and a positive correlation between l-DLPFC GABA levels, but not Glx, and minimal oxygen saturation during sleep (r= 0.62,P= 0.0005). By contrast, no group differences or oxygenation associations were found for levels of GABA or Glx in right or left hippocampal region. These findings are interpreted in terms of a pathophysiological model of SDB in which hypoxia-mediated inhibitory neurotransmission deficit in DLPFC could lead to hyperexcitability and, potentially neuronal dysfunction and cognitive decline.

scholarly journals Mechanistic link between right prefrontal cortical activity and anxious arousal revealed using transcranial magnetic stimulation in healthy subjects

2019 ◽  
Vol 45 (4) ◽  
pp. 694-702 ◽  
Author(s):  
Nicholas L. Balderston ◽  
Emily M. Beydler ◽  
Camille Roberts ◽  
Zhi-De Deng ◽  
Thomas Radman ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Healthy Subjects ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Subcortical Structures ◽  
Prefrontal Cortical ◽  
Dorsolateral Prefrontal ◽  
Before And After ◽  
The Right

AbstractMuch of the mechanistic research on anxiety focuses on subcortical structures such as the amygdala; however, less is known about the distributed cortical circuit that also contributes to anxiety expression. One way to learn about this circuit is to probe candidate regions using transcranial magnetic stimulation (TMS). In this study, we tested the involvement of the dorsolateral prefrontal cortex (dlPFC), in anxiety expression using 10 Hz repetitive TMS (rTMS). In a within-subject, crossover experiment, the study measured anxiety in healthy subjects before and after a session of 10 Hz rTMS to the right dorsolateral prefrontal cortex (dlPFC). It used threat of predictable and unpredictable shock to induce anxiety and anxiety potentiated startle to assess anxiety. Counter to our hypotheses, results showed an increase in anxiety-potentiated startle following active but not sham rTMS. These results suggest a mechanistic link between right dlPFC activity and physiological anxiety expression. This result supports current models of prefrontal asymmetry in affect, and lays the groundwork for further exploration into the cortical mechanisms mediating anxiety, which may lead to novel anxiety treatments.

scholarly journals Transcranial direct current stimulation (tDCS) over vmPFC modulates interactions between reward and emotion in delay discounting

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Aurélie L. Manuel ◽  
Nicholas W. G. Murray ◽  
Olivier Piguet
Keyword(s):  
Prefrontal Cortex ◽  
Delay Discounting ◽  
Dorsolateral Prefrontal Cortex ◽  
Positive Emotions ◽  
Healthy Individuals ◽  
Trade Offs ◽  
Cathodal Tdcs ◽  
Dorsolateral Prefrontal ◽  
Stimulation Of

AbstractDelay discounting requires computing trade-offs between immediate-small rewards and later-larger rewards. Negative and positive emotions shift decisions towards more or less impulsive responses, respectively. Models have conceptualized this trade-off by describing an interplay between “emotional” and “rational” processes, with the former involved during immediate choices and relying on the ventromedial prefrontal cortex (vmPFC), and the latter involved in long-term choices and relying on the dorsolateral prefrontal cortex (dlPFC). Whether stimulation of the vmPFC modulates emotion-induced delay discounting remains unclear. We applied tDCS over the vmPFC in 20 healthy individuals during a delay discounting task following an emotional (positive, negative) or neutral induction. Our results showed that cathodal tDCS increased impulsivity after positive emotions in high impulsivity trials. For low impulsivity trials, anodal tDCS decreased impulsivity following neutral induction compared with emotional induction. Our findings demonstrate that the vmPFC integrates reward and emotion most prominently in situations of increased impulsivity, whereas when higher cognitive control is required the vmPFC appears to be less engaged, possibly due to recruitment of the dlPFC. Understanding how stimulation and emotion influence decision-making at the behavioural and neural levels holds promise to develop interventions to reduce impulsivity.

scholarly journals Using functional connectivity changes associated with cognitive fatigue to delineate a fatigue network

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
G. R. Wylie ◽  
B. Yao ◽  
H. M. Genova ◽  
M. H. Chen ◽  
J. DeLuca
Keyword(s):  
Prefrontal Cortex ◽  
Functional Connectivity ◽  
Dorsolateral Prefrontal Cortex ◽  
Functional Neuroimaging ◽  
Anterior Cingulate ◽  
Healthy Individuals ◽  
Dorsal Anterior Cingulate Cortex ◽  
Mental Work ◽  
Cognitive Fatigue ◽  
Dorsolateral Prefrontal

AbstractCognitive fatigue, or fatigue related to mental work, is a common experience. A growing body of work using functional neuroimaging has identified several regions that appear to be related to cognitive fatigue and that potentially comprise a “fatigue network”. These include the striatum of the basal ganglia, the dorsolateral prefrontal cortex (DLPFC), the dorsal anterior cingulate cortex (dACC), the ventro-medial prefrontal cortex (vmPFC) and the anterior insula. However, no work has been conducted to assess whether the connectivity between these regions changes as a function of cognitive fatigue. We used a task-based functional neuroimaging paradigm to induce fatigue in 39 healthy individuals, regressed the signal associated with the task out of the data, and investigated how the functional connectivity between these regions changed as cognitive fatigue increased. We observed functional connectivity between these regions and other frontal regions largely decreased as cognitive fatigue increased while connectivity between these seeds and more posterior regions increased. Furthermore the striatum, the DLPFC, the insula and the vmPFC appeared to be central ‘nodes’ or hubs of the fatigue network. These findings represent the first demonstration that the functional connectivity between these areas changes as a function of cognitive fatigue.

scholarly journals Effects of Mindfulness Training on Emotion Regulation in Patients with Depression: Reduced Dorsolateral Prefrontal Cortex Activation Indexes Early Beneficial Changes

2019 ◽  
Author(s):  
Thorsten Barnhofer ◽  
Tim Reess ◽  
Maria Fissler ◽  
Emilia Winnebeck ◽  
Simone Grimm ◽  
...  
Keyword(s):  
Emotion Regulation ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Negative Mood ◽  
Affective Stimuli ◽  
Fmri Study ◽  
Dorsolateral Prefrontal ◽  
Before And After ◽  
Highly Correlated ◽  
The Right

Mindfulness-based interventions (MBI) have been found to be a promising approach for the treatment of recurrent courses of depression. However, little is known about their neural mechanisms. This fMRI study set out to investigate activation changes in fronto-limbic regions during implicit emotion regulation. Depressed patients with a recurrent lifetime history were randomized to receive a two-week MBI (N=16 completers) or psycho-education and resting (PER, N=22 completers). Before and after, patients underwent fMR imaging while labelling the affect of angry, happy, and neutral facial expressions and completed questionnaires assessing ruminative brooding, the ability to decentre from such thinking, and depressive symptoms. Activation decreased in the right dorsolateral prefrontal cortex (dlPFC) in response to angry faces following MBI, but not following PER. This change was highly correlated with increased decentering, decreased brooding and decreased symptoms. Amygdala activation in response to happy faces decreased following PER, while the MBI group showed a small but insignificant increase. The dlPFC is involved in emotion regulation, namely reappraisal or suppression of negative emotions. Decreased right dlPFC activation might indicate that, following the MBI, patients abstained from engaging in elaboration or suppression of negative affective stimuli; a putatively important mechanism for preventing the escalation of negative mood.

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