scholarly journals Identifying serotonergic mechanisms underlying the corticolimbic response to threat in humans

2013 ◽  
Vol 368 (1615) ◽  
pp. 20120192 ◽  
Author(s):  
Patrick M. Fisher ◽  
Ahmad R. Hariri
Keyword(s):  
Molecular Mechanisms ◽  
Treatment Strategies ◽  
Blood Oxygen Level Dependent ◽  
Imaging Genetics ◽  
Neural Pathways ◽  
Blood Oxygen Level ◽  
Pharmacological Challenge ◽  
Positron Emission ◽  
Methodological Approaches ◽  
Circuit Function

A corticolimbic circuit including the amygdala and medial prefrontal cortex (mPFC) plays an important role in regulating sensitivity to threat, which is heightened in mood and anxiety disorders. Serotonin is a potent neuromodulator of this circuit; however, specific serotonergic mechanisms mediating these effects are not fully understood. Recent studies have evaluated molecular mechanisms mediating the effects of serotonin signalling on corticolimbic circuit function using a multi-modal neuroimaging strategy incorporating positron emission tomography and blood oxygen level-dependent functional magnetic resonance imaging. This multi-modal neuroimaging strategy can be integrated with additional techniques including imaging genetics and pharmacological challenge paradigms to more clearly understand how serotonin signalling modulates neural pathways underlying sensitivity to threat. Integrating these methodological approaches offers novel opportunities to identify mechanisms through which serotonin signalling contributes to differences in brain function and behaviour, which in turn can illuminate factors that confer risk for illness and inform the development of more effective treatment strategies.

scholarly journals Recent advances in renal imaging

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1867 ◽  
Author(s):  
Joshua M. Thurman ◽  
Faikah Gueler
Keyword(s):  
Kidney Diseases ◽  
Treatment Strategies ◽  
Blood Oxygen Level Dependent ◽  
Great Promise ◽  
Blood Oxygen Level ◽  
Bold Mri ◽  
Contrast Enhanced ◽  
Radiologic Imaging ◽  
Wide Range ◽  
New Treatment

Kidney diseases can be caused by a wide range of genetic, hemodynamic, toxic, infectious, and autoimmune factors. The diagnosis of kidney disease usually involves the biochemical analysis of serum and blood, but these tests are often insufficiently sensitive or specific to make a definitive diagnosis. Although radiologic imaging currently has a limited role in the evaluation of most kidney diseases, several new imaging methods hold great promise for improving our ability to non-invasively detect structural, functional, and molecular changes within the kidney. New methods, such as dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and blood oxygen level-dependent (BOLD) MRI, allow functional imaging of the kidney. The use of novel contrast agents, such as microbubbles and nanoparticles, allows the detection of specific molecules in the kidney. These methods could greatly advance our ability to diagnose disease and also to safely monitor patients over time. This could improve the care of individual patients, and it could also facilitate the evaluation of new treatment strategies.

Neurobiology of Addiction

2017 ◽  
Author(s):  
Alex Gogliettino ◽  
Marc Potenza ◽  
Sarah Yip ◽  
Yasmin Zakiniaeiz ◽  
Zu Wei Zhai
Keyword(s):  
Brain Function ◽  
Treatment Strategies ◽  
Current Treatment ◽  
Social Consequences ◽  
Imaging Genetics ◽  
Negative Consequences ◽  
Addictive Disorders ◽  
Positron Emission ◽  
Controlled Gambling

Addiction is a disorder characterized by poorly controlled substance use despite negative health and social consequences. Additionally, the only behavioral addiction recognized in the main text of the DSM-5, gambling disorder, presents similarly to many substance addictions with respect to the underlying neurobiology and poorly controlled gambling despite negative consequences (e.g., financial, familial problems). This review first provides an overview of the diagnostic criteria for addictive disorders—both substance and nonsubstance—and subsequently reviews the extant literature examining epidemiology, including global prevalence and co-occurring disorders, as well as differences in addicted and nonaddicted groups with respect to genotype, brain function, and neurochemical systems. Last, the prognosis, quality of life, and current treatment strategies for addictions are discussed. The review also includes tables and figures to supplement the text, summarizes important points, and provides visual representations of tasks used to study cognitive aspects of addictions and addiction pathophysiology. This review contains 5 figures, 5 tables, and 80 references. Key words: brain function, cognitive function, epidemiology, functional magnetic resonance imaging, genetics, neurochemistry, positron emission tomography, treatment

Imaging of Convergence Insufficiency Treatment Effects (ICITE) Pilot Study: Design and Methods

2017 ◽  
pp. 207-215
Keyword(s):  
Treatment Effects ◽  
Treatment Strategies ◽  
Blood Oxygen Level Dependent ◽  
Future Research ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
Two Phase ◽  
Convergence Insufficiency ◽  
Imaging Results ◽  
Random Dot Stereogram

Background: The blood-oxygen-level-dependent (BOLD) signal from functional magnetic resonance imaging (fMRI) identifies brain activation during specific tasks.1,2 This paper describes the design and methodology of the Imaging of Convergence Insufficiency Treatment Effects (ICITE) Study, a two-phase study comparing BOLD activations during vergence eye movements in symptomatic convergence insufficiency (CI) subjects (1) to those with normal binocular vision (NBV) and (2) after office-based vergence/accommodative therapy (OBVAT) versus office-based placebo therapy (OBPT). Methods: Young adults, 18 to 30 years, with NBV or symptomatic CI (near exophoria at least 4Δ [prism diopters] greater than at distance, receded near point of convergence [NPC], and insufficient positive fusional vergence [PFV]) were enrolled. During fMRI scanning, subjects were instructed to fuse a random-dot stereogram stimulus with vergence demands ranging from -3Δ to +25Δ. CI subjects were then randomized to 12 weeks of OBVAT or OBPT. Vision and fMRI examination at outcome were performed by a masked examiner. BOLD signal at baseline was compared between NBV and CI patients. Later, the BOLD response at baseline was compared to that following vision therapy for those with CI. Conclusion: The imaging results are expected to advance understanding of neurological mechanisms of CI and the effects of therapy on the vergence system, which in turn may guide development of future research that could lead to new treatment strategies.

scholarly journals Task-Evoked BOLD Responses Are Normal in Areas of Diaschisis After Stroke

2008 ◽  
Vol 23 (1) ◽  
pp. 52-57 ◽  
Author(s):  
Damien A. Fair ◽  
Abraham Z. Snyder ◽  
Lisa Tabor Connor ◽  
Binyam Nardos ◽  
Maurizio Corbetta
Keyword(s):  
Blood Flow ◽  
Block Design ◽  
Inferior Frontal Gyrus ◽  
Blood Oxygen Level Dependent ◽  
Bold Signal ◽  
Blood Oxygen Level ◽  
Positron Emission ◽  
Fmri Study ◽  
Bold Responses ◽  
Word Stem Completion

Objective. Cerebral infarction can cause diaschisis, a reduction of blood flow and metabolism in areas of the cortex distant from the site of the lesion. Although the functional magnetic resonance imaging (fMRI) blood oxygen level dependent (BOLD) signal is increasingly used to examine the neural correlates of recovery in stroke, its reliability in areas of diaschisis is uncertain. Design. The effect of chronic diaschisis as measured by resting positron emission tomography on task-evoked BOLD responses during word-stem completion in a block design fMRI study was examined in 3 patients, 6 months after a single left hemisphere stroke involving the inferior frontal gyrus and operculum. Results. The BOLD responses were minimally affected in areas of chronic diaschisis. Conclusions. Within the confines of this study, the mechanism underlying the BOLD signal, which includes a mismatch between neuronally driven increases in blood flow and a corresponding increase in oxygen use, appears to be intact in areas of chronic diaschisis.

Neurobiology of Addiction

2021 ◽  
Author(s):  
Alex Gogliettino ◽  
Marc Potenza ◽  
Sarah Yip ◽  
Yasmin Zakiniaeiz ◽  
Zu Wei Zhai
Keyword(s):  
Brain Function ◽  
Treatment Strategies ◽  
Current Treatment ◽  
Social Consequences ◽  
Imaging Genetics ◽  
Negative Consequences ◽  
Addictive Disorders ◽  
Positron Emission ◽  
Controlled Gambling

Addiction is a disorder characterized by poorly controlled substance use despite negative health and social consequences. Additionally, the only behavioral addiction recognized in the main text of the DSM-5, gambling disorder, presents similarly to many substance addictions with respect to the underlying neurobiology and poorly controlled gambling despite negative consequences (e.g., financial, familial problems). This review first provides an overview of the diagnostic criteria for addictive disorders—both substance and nonsubstance—and subsequently reviews the extant literature examining epidemiology, including global prevalence and co-occurring disorders, as well as differences in addicted and nonaddicted groups with respect to genotype, brain function, and neurochemical systems. Last, the prognosis, quality of life, and current treatment strategies for addictions are discussed. The review also includes tables and figures to supplement the text, summarizes important points, and provides visual representations of tasks used to study cognitive aspects of addictions and addiction pathophysiology. This review contains 5 figures, 6 tables, and 81 references. Key words: brain function, cognitive function, epidemiology, functional magnetic resonance imaging, genetics, neurochemistry, positron emission tomography, treatment

scholarly journals A new trigemino-nociceptive stimulation model for event-related fMRI

Cephalalgia ◽  
2009 ◽  
Vol 30 (4) ◽  
pp. 475-485 ◽  
Author(s):  
A Stankewitz ◽  
HL Voit ◽  
U Bingel ◽  
C Peschke ◽  
A May
Keyword(s):  
Trigeminal Nerve ◽  
Blood Oxygen Level Dependent ◽  
Pain Processing ◽  
Nociceptive Stimulation ◽  
Blood Oxygen Level ◽  
Trigeminal Pain ◽  
Trigeminal Nuclei ◽  
Positron Emission ◽  
Magnetic Stimulus ◽  
Anatomical Localization

Functional imaging of human trigemino-nociceptive processing provides meaningful insights into altered pain processing in head and face pain diseases. Although functional magnetic resonance imaging (fMRI) offers high temporal and spatial resolution, most studies available were done with radioligand-positron emission tomography, as fMRI requires non-magnetic stimulus equipment and fast on–off conditions. We developed a new approach for painful stimulation of the trigeminal nerve that can be implemented within an event-related design using fMRI and aimed to detect increased blood-oxygen-level-dependent (BOLD) signals as surrogate markers of trigeminal pain processing. Using an olfactometer, 20 healthy volunteers received intranasally standardized trigeminal nociceptive stimuli (ammonia gas) as well as olfactory (rose odour) and odourless control stimuli (air puffs). Imaging revealed robust BOLD responses to the trigeminal nociceptive stimulation in cortical and subcortical brain areas known to be involved in pain processing. Focusing on the trigeminal pain pathway, significant activations were observed bilaterally in brainstem areas at the trigeminal nerve entry zone, which are agreeable with the principal trigeminal nuclei. Furthermore, increased signal changes could be detected ipsilaterally at anatomical localization of the trigeminal ganglion and bilaterally in the rostral medulla, which probably represents the spinal trigeminal nuclei. However, brainstem areas involved in the endogenous pain control system that are close to this anatomical localization, such as raphe nuclei, have to be discussed. Our findings suggest that mapping trigeminal pain processing using fMRI with this non-invasive experimental design is feasible and capable of evoking specific activations in the trigeminal nociceptive system. This method will provide an ideal opportunity to study the trigeminal pain system in both health and pathological conditions such as idiopathic headache disorders.

scholarly journals Resting-state functional MRI signal fluctuations are correlated with brain amyloid-β deposition

2021 ◽  
Author(s):  
Norman Scheel ◽  
Takashi Tarumi ◽  
Tsubasa Tomoto ◽  
Munro Cullum ◽  
Rong Zhang ◽  
...  
Keyword(s):  
Functional Mri ◽  
Resting State ◽  
Low Frequency ◽  
Amyloid Β ◽  
Standardized Uptake Value ◽  
Blood Oxygen Level Dependent ◽  
Brain Regions ◽  
Blood Oxygen Level ◽  
Positron Emission ◽  
Local Correlations

Mounting evidence suggests that amyloid-β (Aβ) and vascular etiologies are intertwined in the pathogenesis of Alzheimer′s disease. Spontaneous fluctuations of the brain blood-oxygen-level-dependent (BOLD) signal, as measured by resting-state functional MRI (rs-fMRI), have been shown to be associated with neuronal activities as well as cerebrovascular hemodynamics. Nevertheless, it is unclear if rs-fMRI BOLD fluctuations are associated with brain Aβ deposition in individuals with an elevated risk of Alzheimer's disease. We recruited 33 patients with amnestic mild cognitive impairment who underwent rs-fMRI and positron emission tomography (PET). The Aβ standardized uptake value ratio (SUVR) was calculated with cortical white matter as the reference region to improve sensitivity for cortical Aβ quantification. We calculated the amplitudes of low-frequency fluctuations (ALFF) of local BOLD signals in the frequency band of 0.01-0.08 Hz. Applying physiological/vascular signal regression in stepwise increasing levels on the rs-fMRI data, we examined whether local correlations between ALFF and brain Aβ deposition were driven by vascular hemodynamics, spontaneous neuronal activities, or both. We found that ALFF and Aβ SUVR were negatively correlated in brain regions involving the default-mode and visual networks, with peak correlation at the precuneus, and angular, lingual, and fusiform gyri. Regions with higher ALFF had less Aβ accumulation. The correlated cluster sizes in MNI space were reduced from 3018 mm3 with no physiological/vascular regression to 1072 mm3 with strong physiological/vascular regression, with mean cluster r values at approximately -0.47. Results demonstrate that both vascular hemodynamics and neuronal activities, as reflected by BOLD fluctuations, are negatively associated with brain Aβ deposition. These findings further imply that local brain blood fluctuations due to either vascular hemodynamics or neuronal activities can affect Aβ homeostasis.

Radio-Susceptibility of Nasopharyngeal Carcinoma: Focus on Epstein- Barr Virus, MicroRNAs, Long Non-Coding RNAs and Circular RNAs

2020 ◽  
Vol 13 (3) ◽  
pp. 192-205 ◽  
Author(s):  
Fanghong Lei ◽  
Tongda Lei ◽  
Yun Huang ◽  
Mingxiu Yang ◽  
Mingchu Liao ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Regulatory Networks ◽  
Epstein Barr Virus ◽  
Molecular Mechanisms ◽  
Acquired Resistance ◽  
Treatment Strategies ◽  
Circular Rnas ◽  
Barr Virus ◽  
Non Coding Rnas ◽  
Epstein Barr

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.

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