scholarly journals The effect of functionally-guided-connectivity-based rTMS on amygdala activation

2020 ◽  
Author(s):  
L. Beynel ◽  
E. Campbell ◽  
M. Naclerio ◽  
J.T. Galla ◽  
A. Ghosal ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Interaction Analysis ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
A Priori ◽  
Video Clips ◽  
Amygdala Activation ◽  
Connected Node ◽  
Amygdala Activity ◽  
Psychophysiological Interaction ◽  
Electric Field Penetration

AbstractRepetitive transcranial magnetic stimulation (rTMS) has fundamentally transformed how we treat psychiatric disorders, but is still in need of innovation to optimally correct dysregulation that occurs throughout the fronto-limbic network. rTMS is often applied over the prefrontal cortex, a central node in this network, but less attention is given to subcortical areas because they lie at depths beyond the electric field penetration of rTMS. Recent studies have demonstrated that the effectiveness of rTMS is dependent on the functional connectivity between deep subcortical areas and superficial targets, indicating that leveraging such connectivity may improve dosing approaches for rTMS interventions. The current preliminary study, therefore, sought to test whether task-related, fMRI-connectivity-based rTMS could be used to modulate amygdala activation through its connectivity with the medial prefrontal cortex (mPFC). For this purpose, fMRI was collected on participants to identify a node in the mPFC that showed the strongest negative connectivity with right amygdala, as defined by psychophysiological interaction analysis. To promote long-lasting Hebbian-like effects, and potentially stronger modulation, 5Hz rTMS was then applied to this target as participants viewed frightening video-clips that engaged the fronto-limbic network. Post-rTMS fMRI results revealed promising increases in both the left mPFC and right amygdala, for active rTMS compared to sham. While these modulatory findings are promising, they differ from the a priori expectation that excitatory 5Hz rTMS over a negatively connected node would reduce amygdala activity. As such, further research is needed to better understand how connectivity influences TMS effects on distal structures, and to leverage this information to improve therapeutic applications.

scholarly journals The Effects of Functionally Guided, Connectivity-Based rTMS on Amygdala Activation

2021 ◽  
Vol 11 (4) ◽  
pp. 494
Author(s):  
Lysianne Beynel ◽  
Ethan Campbell ◽  
Maria Naclerio ◽  
Jeffrey T. Galla ◽  
Angikar Ghosal ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Psychiatric Disorders ◽  
Interaction Analysis ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Preliminary Evidence ◽  
Therapeutic Effects ◽  
Subcortical Structures ◽  
Video Clips ◽  
Amygdala Activation ◽  
Psychophysiological Interaction

While repetitive transcranial magnetic stimulation (rTMS) is widely used to treat psychiatric disorders, innovations are needed to improve its efficacy. An important limitation is that while psychiatric disorders are associated with fronto-limbic dysregulation, rTMS does not have sufficient depth penetration to modulate affected subcortical structures. Recent advances in task-related functional connectivity provide a means to better link superficial and deeper cortical sources with the possibility of increasing fronto-limbic modulation to induce stronger therapeutic effects. The objective of this pilot study was to test whether task-related, connectivity-based rTMS could modulate amygdala activation through its connectivity with the medial prefrontal cortex (mPFC). fMRI was collected to identify a node in the mPFC showing the strongest connectivity with the amygdala, as defined by psychophysiological interaction analysis. To promote Hebbian-like plasticity, and potentially stronger modulation, 5 Hz rTMS was applied while participants viewed frightening video-clips that engaged the fronto-limbic network. Significant increases in both the mPFC and amygdala were found for active rTMS compared to sham, offering promising preliminary evidence that functional connectivity-based targeting may provide a useful approach to treat network dysregulation. Further research is needed to better understand connectivity influences on rTMS effects to leverage this information to improve therapeutic applications.

Early Amygdala Activation and Later Ventromedial Prefrontal Cortex Activation During Anger Induction and Imagery

2020 ◽  
Vol 1 (1) ◽  
pp. 1-8
Author(s):  
Darin D. Dougherty ◽  
Tina Chou ◽  
Ulrike Buhlmann ◽  
Scott L. Rauch ◽  
Thilo Deckersbach
Keyword(s):  
Prefrontal Cortex ◽  
Time Course ◽  
A Priori ◽  
Region Of Interest ◽  
Ventromedial Prefrontal Cortex ◽  
Amygdala Activation ◽  
Positron Emission ◽  
Initial Onset ◽  
The Individual ◽  
Neutral Conditions

Background: Neurobiological studies implicate the amygdala and related limbic/paralimbic structures, such as the ventromedial prefrontal cortex (VMPFC), in anger and aggression. Previous studies of self-generated anger using Positron Emission Tomography (PET) have consistently documented a lack of amygdala activation during anger. Objective: We investigated the hypothesis that a lack of amygdala activation during anger is due to differences in the time course of amygdala and VMPFC activation. Specifically, we explored whether the amygdala is involved in the early phases of anger experience which is later followed by increased VMPFC activation. Methods: Eighteen healthy control participants underwent fMRI. We adapted an anger induction paradigm previously used in our PET study, in which neutral and angry states were induced using autobiographical scripts. The hypothesized time course of amygdala and VMPFC activation during acute anger induction and imagery were modeled. Region of interest (ROI) analyses were used to identify significant a priori region activation, and correlations were run between signal values and VAS anger ratings. Results: Amygdala activation increased during the acute phase of anger induction and decreased during the later phase of anger imagery, whereas VMPFC activation decreased during anger induction and increased during anger imagery, compared to the neutral conditions. In addition, negative correlations were found between self-ratings of anger and bilateral VMPFC activation. Conclusions: Overall, our results suggest that the amygdala may be active at the initial onset of anger while the VMPFC is activated over time as the individual sustains and perhaps regulates that emotional state.

scholarly journals A pilot trial of repetitive transcranial magnetic stimulation of the dorsomedial prefrontal cortex in anorexia nervosa: resting fMRI correlates of response

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
D. Blake Woodside ◽  
Katharine Dunlop ◽  
Charlene Sathi ◽  
Eileen Lam ◽  
Brigitte McDonald ◽  
...  
Keyword(s):  
Anorexia Nervosa ◽  
Prefrontal Cortex ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Trial Registration ◽  
Angular Gyrus ◽  
Open Label ◽  
Compulsive Disorder ◽  
Dorsomedial Prefrontal Cortex

Abstract Background Patients with anorexia nervosa (AN) face severe and chronic illness with high mortality rates, despite our best currently available conventional treatments. Repetitive transcranial magnetic stimulation (rTMS) has shown increasing efficacy in treatment-refractory cases across a variety of psychiatric disorders comorbid with AN, including major depression, Obsessive Compulsive Disorder (OCD), and Post traumatic Stress Disorder (PTSD). However, to date few studies have examined the effects of a course of rTMS on AN pathology itself. Methods Nineteen patients with AN underwent a 20–30 session open-label course of dorsomedial prefrontal rTMS for comorbid Major Depressive Disorder (MDD) ± PTSD. Resting-state functional MRI was acquired at baseline in 16/19 patients. Results Following treatment, significant improvements were seen in core AN pathology on the EDE global scale, and to a lesser extent on the shape and weight concerns subscales. Significant improvements in comorbid anxiety, and to a lesser extent depression, also ensued. The greatest improvements were seen in patients with lower baseline functional connectivity from the dorsomedial prefrontal cortex (DMPFC) target to regions in the right frontal pole and left angular gyrus. Conclusions Despite the limited size of this preliminary, open-label study, the results suggest that rTMS is safe in AN, and may be useful in addressing some core domains of AN pathology. Other targets may also be worth studying in this population, in future sham-controlled trials with larger sample sizes. Trial registration Trial registration ClinicalTrials.gov NCT04409704. Registered May 282,020. Retrospectively registered.

Repetitive Transcranial Magnetic Stimulation Improves Depersonalization: A Case Report

CNS Spectrums ◽  
2004 ◽  
Vol 9 (5) ◽  
pp. 375-376 ◽  
Author(s):  
Alejandro M. Jiménez-Genchi
Keyword(s):  
Prefrontal Cortex ◽  
Case Report ◽  
Transcranial Magnetic Stimulation ◽  
Magnetic Stimulation ◽  
Dorsolateral Prefrontal Cortex ◽  
Repetitive Transcranial Magnetic Stimulation ◽  
Treatment Resistant ◽  
Depersonalization Disorder ◽  
Dorsolateral Prefrontal

AbstractDepersonalization disorder is a poorly understood and treatment-resistant condition. This report describes a patient with depersonalization disorder who underwent six sessions of repetitive transcranial magnetic stimulation on the left dorsolateral prefrontal cortex. Repetitive transcranial magnetic stimulation produced a 28% reduction on depersonalization scores.

scholarly journals Kynurenine pathway in post-mortem prefrontal cortex and cerebellum in schizophrenia: relationship with monoamines and symptomatology

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Amira Ben Afia ◽  
Èlia Vila ◽  
Karina S. MacDowell ◽  
Aida Ormazabal ◽  
Juan C. Leza ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
High Performance ◽  
Interaction Analysis ◽  
Kynurenine Pathway ◽  
Psychotic Symptoms ◽  
Post Mortem ◽  
Control Subjects ◽  
Network Interaction ◽  
Hydroxyindoleacetic Acid ◽  
Cortical Circuit

Abstract Background The cortico-cerebellar-thalamic-cortical circuit has been implicated in the emergence of psychotic symptoms in schizophrenia (SZ). The kynurenine pathway (KP) has been linked to alterations in glutamatergic and monoaminergic neurotransmission and to SZ symptomatology through the production of the metabolites quinolinic acid (QA) and kynurenic acid (KYNA). Methods This work describes alterations in KP in the post-mortem prefrontal cortex (PFC) and cerebellum (CB) of 15 chronic SZ patients and 14 control subjects in PFC and 13 control subjects in CB using immunoblot for protein levels and ELISA for interleukins and QA and KYNA determinations. Monoamine metabolites were analysed by high-performance liquid chromatography and SZ symptomatology was assessed by Positive and Negative Syndrome Scale (PANSS). The association of KP with inflammatory mediators, monoamine metabolism and SZ symptomatology was explored. Results In the PFC, the presence of the anti-inflammatory cytokine IL-10 together with IDO2 and KATII enzymes decreased in SZ, while TDO and KMO enzyme expression increased. A network interaction analysis showed that in the PFC IL-10 was coupled to the QA branch of the kynurenine pathway (TDO-KMO-QA), whereas IL-10 associated with KMO in CB. KYNA in the CB inversely correlated with negative and general PANSS psychopathology. Although there were no changes in monoamine metabolite content in the PFC in SZ, a network interaction analysis showed associations between dopamine and methoxyhydroxyphenylglycol degradation metabolite. Direct correlations were found between general PANSS psychopathology and the serotonin degradation metabolite, 5-hydroxyindoleacetic acid. Interestingly, KYNA in the CB inversely correlated with 5-hydroxyindoleacetic acid in the PFC. Conclusions Thus, this work found alterations in KP in two brain areas belonging to the cortico-cerebellar-thalamic-cortical circuit associated with SZ symptomatology, with a possible impact across areas in 5-HT degradation.

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