scholarly journals Atomoxetine Enhances Connectivity of Prefrontal Networks in Parkinson’s Disease

2016 ◽  
Vol 41 (8) ◽  
pp. 2171-2177 ◽  
Author(s):  
Robin J Borchert ◽  
Timothy Rittman ◽  
Luca Passamonti ◽  
Zheng Ye ◽  
Saber Sami ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
Executive Functions ◽  
Dorsolateral Prefrontal Cortex ◽  
Anterior Cingulate ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
The Brain

Abstract Cognitive impairment is common in Parkinson’s disease (PD), but often not improved by dopaminergic treatment. New treatment strategies targeting other neurotransmitter deficits are therefore of growing interest. Imaging the brain at rest (‘task-free’) provides the opportunity to examine the impact of a candidate drug on many of the brain networks that underpin cognition, while minimizing task-related performance confounds. We test this approach using atomoxetine, a selective noradrenaline reuptake inhibitor that modulates the prefrontal cortical activity and can facilitate some executive functions and response inhibition. Thirty-three patients with idiopathic PD underwent task-free fMRI. Patients were scanned twice in a double-blind, placebo-controlled crossover design, following either placebo or 40-mg oral atomoxetine. Seventy-six controls were scanned once without medication to provide normative data. Seed-based correlation analyses were used to measure changes in functional connectivity, with the right inferior frontal gyrus (IFG) a critical region for executive function. Patients on placebo had reduced connectivity relative to controls from right IFG to dorsal anterior cingulate cortex and to left IFG and dorsolateral prefrontal cortex. Atomoxetine increased connectivity from the right IFG to the dorsal anterior cingulate. In addition, the atomoxetine-induced change in connectivity from right IFG to dorsolateral prefrontal cortex was proportional to the change in verbal fluency, a simple index of executive function. The results support the hypothesis that atomoxetine may restore prefrontal networks related to executive functions. We suggest that task-free imaging can support translational pharmacological studies of new drug therapies and provide evidence for engagement of the relevant neurocognitive systems.

scholarly journals Reducing future fears by suppressing the brain mechanisms underlying episodic simulation

2016 ◽  
Vol 113 (52) ◽  
pp. E8492-E8501 ◽  
Author(s):  
Roland G. Benoit ◽  
Daniel J. Davies ◽  
Michael C. Anderson
Keyword(s):  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Ventromedial Prefrontal Cortex ◽  
Episodic Simulation ◽  
Dorsolateral Prefrontal ◽  
Future Events ◽  
The Right ◽  
Development Of Anxiety ◽  
The Brain

Imagining future events conveys adaptive benefits, yet recurrent simulations of feared situations may help to maintain anxiety. In two studies, we tested the hypothesis that people can attenuate future fears by suppressing anticipatory simulations of dreaded events. Participants repeatedly imagined upsetting episodes that they feared might happen to them and suppressed imaginings of other such events. Suppressing imagination engaged the right dorsolateral prefrontal cortex, which modulated activation in the hippocampus and in the ventromedial prefrontal cortex (vmPFC). Consistent with the role of the vmPFC in providing access to details that are typical for an event, stronger inhibition of this region was associated with greater forgetting of such details. Suppression further hindered participants’ ability to later freely envision suppressed episodes. Critically, it also reduced feelings of apprehensiveness about the feared scenario, and individuals who were particularly successful at down-regulating fears were also less trait-anxious. Attenuating apprehensiveness by suppressing simulations of feared events may thus be an effective coping strategy, suggesting that a deficiency in this mechanism could contribute to the development of anxiety.

Spatiotemporal features of β-γ phase-amplitude coupling in Parkinson’s disease derived from scalp EEG

Brain ◽  
2020 ◽  
Author(s):  
Ruxue Gong ◽  
Mirko Wegscheider ◽  
Christoph Mühlberg ◽  
Richard Gast ◽  
Christopher Fricke ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prefrontal Cortex ◽  
Somatosensory Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Rating Scale ◽  
Depth Analysis ◽  
Dorsolateral Prefrontal ◽  
Phase Amplitude

Abstract Abnormal phase-amplitude coupling between β and broadband-γ activities has been identified in recordings from the cortex or scalp of patients with Parkinson’s disease. While enhanced phase-amplitude coupling has been proposed as a biomarker of Parkinson’s disease, the neuronal mechanisms underlying the abnormal coupling and its relationship to motor impairments in Parkinson’s disease remain unclear. To address these issues, we performed an in-depth analysis of high-density EEG recordings at rest in 19 patients with Parkinson’s disease and 20 age- and sex-matched healthy control subjects. EEG signals were projected onto the individual cortical surfaces using source reconstruction techniques and separated into spatiotemporal components using independent component analysis. Compared to healthy controls, phase-amplitude coupling of Parkinson’s disease patients was enhanced in dorsolateral prefrontal cortex, premotor cortex, primary motor cortex and somatosensory cortex, the difference being statistically significant in the hemisphere contralateral to the clinically more affected side. β and γ signals involved in generating abnormal phase-amplitude coupling were not strictly phase-phase coupled, ruling out that phase-amplitude coupling merely reflects the abnormal activity of a single oscillator in a recurrent network. We found important differences for couplings between the β and γ signals from identical components as opposed to those from different components (originating from distinct spatial locations). While both couplings were abnormally enhanced in patients, only the latter were correlated with clinical motor severity as indexed by part III of the Movement Disorder Society Unified Parkinson’s Disease Rating Scale. Correlations with parkinsonian motor symptoms of such inter-component couplings were found in premotor, primary motor and somatosensory cortex, but not in dorsolateral prefrontal cortex, suggesting motor domain specificity. The topography of phase-amplitude coupling demonstrated profound differences in patients compared to controls. These findings suggest, first, that enhanced phase-amplitude coupling in Parkinson’s disease patients originates from the coupling between distinct neural networks in several brain regions involved in motor control. Because these regions included the somatosensory cortex, abnormal phase-amplitude coupling is not exclusively tied to the hyperdirect tract connecting cortical regions monosynaptically with the subthalamic nucleus. Second, only the coupling between β and γ signals from different components appears to have pathophysiological significance, suggesting that therapeutic approaches breaking the abnormal lateral coupling between neuronal circuits may be more promising than targeting phase-amplitude coupling per se.

scholarly journals TRANSCRANIAL DIRECT STIMULATION IN THE NEUROMODULATION OF CONTROLLING MAIN SYMPTOMS OF PARKINSON’S DISEASE: A CASE STUDY

2022 ◽  
Author(s):  
Letizzia DALL’AGNOL ◽  
Alice Medeiros de SOUZA ◽  
Lilian Campos AMADEU ◽  
Eleni VOSNIADOU ◽  
Fernanda Ishida CORRÊA
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Motor Control ◽  
Prefrontal Cortex ◽  
Dorsolateral Prefrontal Cortex ◽  
Primary Motor Cortex ◽  
Motor Coordination ◽  
Neurodegenerative Disorder ◽  
Direct Stimulation ◽  
Dorsolateral Prefrontal

Parkinson’s disease (PD) is a central nervous system neurodegenerative disorder that primarily affects the motor system, decreasing motor coordination, balance and generating tremors, and a progressive loss of everyday mobility, including walking. This study was conducted to verify the effects of Transcranial Direct Current Stimulation (tDCS) on balance, motor control, and the quality of life in Parkinson’s disease patients. The patient received three treatments consisting of 10 sessions of 20 minutes each and a one-week interval between treatments. Active stimulation was applied on the primary motor cortex (M1), the dorsolateral prefrontal cortex (DLPFC), and the dorsolateral prefrontal cortex (D Sham-tDCS. DLPFC stimulation produced the best improvements in terms of motor control, balance, gait, and overall PD symptoms, as evaluated by different scales and questionnaires. As a result, active stimulation of the DLPFC produced superior outcomes and may contribute to treating Parkinson’s disease.

scholarly journals Self-compassion and dorsolateral prefrontal cortex activity during sad self-face recognition in depressed adolescents

2020 ◽  
pp. 1-10
Author(s):  
Guanmin Liu ◽  
Na Zhang ◽  
Jia Yuan Teoh ◽  
Christine Egan ◽  
Thomas A. Zeffiro ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Face Recognition ◽  
Dorsolateral Prefrontal Cortex ◽  
Adolescent Depression ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Depression Severity ◽  
Self Compassion ◽  
Dorsolateral Prefrontal ◽  
The Right

Abstract Background Given the prevalence of adolescent depression and the modest effects of current treatments, research ought to inform development of effective intervention strategies. Self-compassion is inversely associated with depression, and self-compassion interventions have demonstrated promising effects on reducing depression. However, little is known about the neural mechanisms underlying that relationship. Maladaptive self-processing is a characteristic of depression that contributes to the onset and chronicity of depression. Because our own face is an automatic and direct cue for self-processing, this study investigated whether self-compassion was associated with neural responses during sad v. neutral self-face recognition and explore their relationship with depression severity in depressed adolescents and healthy controls (HCs). Methods During functional magnetic resonance imaging, 81 depressed youth and 37 HCs were instructed to identify whether morphed self or other faces with sad, happy, or neutral expressions resembled their own. Results Self-compassion correlated negatively with activity during sad v. neutral self-face recognition in the dorsal anterior cingulate cortex in the total sample, and in the right posterior cingulate cortex/precuneus in HCs, respectively. In depressed adolescents, higher self-compassion correlated with lower activity during sad v. neutral self-face recognition in the right dorsolateral prefrontal cortex (DLPFC), implying that less cognitive effort might be needed to avoid dwelling on sad self-faces and/or regulate negative affect induced by them. Moreover, higher self-compassion mediated the relationship between lower DLPFC activity and reduced depression severity. Conclusions Our findings imply that DLPFC activity might be a biological marker of a successful self-compassion intervention as potential treatment for adolescent depression.

scholarly journals Dorsolateral Prefrontal Cortex: A Possible Target for Modulating Dyskinesias in Parkinson's Disease by Repetitive Transcranial Magnetic Stimulation

2008 ◽  
Vol 2008 ◽  
pp. 1-6 ◽  
Author(s):  
I. Rektorova ◽  
S. Sedlackova ◽  
S. Telecka ◽  
A. Hlubocky ◽  
I. Rektor
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Motor Cortex ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Controlled Study ◽  
Dorsolateral Prefrontal

We studied whether five sessions of 10 Hz repetitive transcranial magnetic stimulation (rTMS treatment) applied over the dorsolateral prefrontal cortex (DLPFC) or the primary motor cortex (MC) in advanced Parkinson's disease (PD) patients would have any effect on L-dopa-induced dyskinesias and cortical excitability. We aimed at a randomised, controlled study. Single-pulse transcranial magnetic stimulation (TMS), paired-pulse transcranial magnetic stimulation, and the Unified Parkinson's Disease Rating Scale (UPDRS parts III and IV) were performed prior to, immediately after, and one week after an appropriate rTMS treatment. Stimulation of the left DLPFC induced a significant motor cortex depression and a trend towards the improvement of L-dopa-induced dyskinesias.

scholarly journals Prefrontal Cortex Magnetic Stimulation, a Simulation Analysis

2013 ◽  
Vol 8-9 ◽  
pp. 631-638
Author(s):  
Catalin Curta ◽  
Septimiu Crisan ◽  
Radu V. Ciupa
Keyword(s):  
Prefrontal Cortex ◽  
Electric Field ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Sagittal Plane ◽  
Simulation Analysis ◽  
Human Cortex ◽  
Dorsolateral Prefrontal ◽  
The Right ◽  
The Brain

The presented work aims to elucidate where stimulation occurs in the brain during transcranial magnetic stimulation (TMS), taking into account cortical geometry. A realistic computer model of TMS was developed comprising a stimulation coil and the human cortex. The coil was positioned over the right dorsolateral prefrontal cortex (right DLPFC) and the distribution of the induced electric field was analyzed. A computer simulation was constructed, where the coil is positioned at an angle of 450 relative to the sagittal plane. The results highlight the influence of cortical geometry on the distribution of the electric field in the brain and show that the highest values are not obtained directly under the center of the stimulator.

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