A large body of evidence suggests that brain signal complexity (BSC) may be an important indicator of healthy brain functioning or alternately, a harbinger of disease and dysfunction. However, despite recent progress our current understanding of how BSC emerges and evolves in large-scale networks, and the factors that shape these dynamics, remains limited. Here, we utilized resting-state functional near-infrared spectroscopy (rs-fNIRS) to capture and characterize the nature and time course of BSC dynamics within large-scale functional networks in 107 healthy participants ranging from 6-13 years of age.
View Article and Find Full Text PDFA confluence of evidence indicates that brain functional connectivity is not static but rather dynamic. Capturing transient network interactions in the individual brain requires a technology that offers sufficient within-subject reliability. Here, we introduce an individualized network-based dynamic analysis technique and demonstrate that it is reliable in detecting subject-specific brain states during both resting state and a cognitively challenging language task.
View Article and Find Full Text PDFSubstantial clinical heterogeneity and comorbidity inherent amongst mental disorders limit the identification of neuroimaging biomarkers that can reliably track clinical symptoms. Strategies that enable generation of meaningful and replicable neurobiological markers at the individual level will push the field of neuropsychiatry forward in developing efficacious personalized treatment. The current study included 142 adult patients with a primary diagnosis of schizophrenia (SCZ), bipolar (BP), or attention deficit/hyperactivity disorder (ADHD), and 67 patient ratings across four behavioral measures.
View Article and Find Full Text PDFObjective: Accumulating evidence from invasive cortical stimulation mapping and noninvasive neuroimaging studies indicates that brain function may be preserved within brain tumors. However, a noninvasive approach to accurately and comprehensively delineate individual-specific functional networks in the whole brain, especially in brain tissues within and surrounding tumors, is still lacking. The purpose of the study is to develop a clinically useful technique that can map functional regions within tumoral brains.
View Article and Find Full Text PDFThe cerebellum, a structure historically associated with motor control, has more recently been implicated in several higher-order auditory-cognitive functions. However, the exact functional pathways that mediate cerebellar influences on auditory cortex (AC) remain unclear. Here, we sought to identify auditory cortico-cerebellar pathways based on intrinsic functional connectivity magnetic resonance imaging.
View Article and Find Full Text PDFObjective: Current understanding of the neuromodulatory effects of deep brain stimulation (DBS) on large-scale brain networks remains elusive, largely due to the lack of techniques that can reveal DBS-induced activity at the whole-brain level. Using a novel 3T magnetic resonance imaging (MRI)-compatible stimulator, we investigated whole-brain effects of subthalamic nucleus (STN) stimulation in patients with Parkinson disease.
Methods: Fourteen patients received STN-DBS treatment and participated in a block-design functional MRI (fMRI) experiment, wherein stimulations were delivered during "ON" blocks interleaved with "OFF" blocks.
Objective: While much brain research on fibromyalgia (FM) focuses on the study of hyperresponsiveness to painful stimuli, some studies suggest that the increased pain-related brain activity often reported in FM studies may be partially explained by stronger responses to salient aspects of the stimulation rather than, or in addition to, the stimulation's painfulness. Therefore, this study was undertaken to test our hypothesis that FM patients would demonstrate elevated brain responses to both pain onset and offset-2 salient sensory events of opposing valences.
Methods: Thirty-eight FM patients (mean ± SD age 46.
Background: Brainstem-focused mechanisms supporting transcutaneous auricular VNS (taVNS) effects are not well understood, particularly in humans. We employed ultrahigh field (7T) fMRI and evaluated the influence of respiratory phase for optimal targeting, applying our respiratory-gated auricular vagal afferent nerve stimulation (RAVANS) technique.
Hypothesis: We proposed that targeting of nucleus tractus solitarii (NTS) and cardiovagal modulation in response to taVNS stimuli would be enhanced when stimulation is delivered during a more receptive state, i.
Alterations in fractional anisotropy (FA) have been considered to reflect microstructural white matter (WM) changes in disease conditions; however, no study to date has examined WM changes using diffusion tensor imaging (DTI) in adolescents with irritable bowel syndrome (IBS). The objective of the present study was two-fold: (1) to determine whether differences in FA, and other non-FA metrics, were present in adolescents with IBS compared to healthy controls using whole-brain, region of interest (ROI)-restricted tract-based spatial statistics (TBSS) and canonical ROI DTI analyses for the cingulum bundle, and (2) to determine whether these metrics were related to clinical measures of disease duration and pain intensity in the IBS group. A total of 16 adolescents with a Rome III diagnosis of IBS (females = 12; mean age = 16.
View Article and Find Full Text PDFThe aim of this study was to identify structural and functional brain changes that accompanied the transition from chronic (CM; ≥15 headache days/month) to episodic (EM; <15 headache days/month) migraine following prophylactic treatment with onabotulinumtoxinA (BoNT-A). Specifically, we examined whether CM patients responsive to prophylaxis (responders; = 11), as evidenced by a reversal in disease status (defined by at least a 50% reduction in migraine frequency and <15 headache days/month), compared to CM patients whose migraine frequency remained unchanged (non-responders; = 12), showed differences in cortical thickness using surface-based morphometry. We also investigated whether areas showing group differences in cortical thickness displayed altered resting-state functional connectivity (RS-FC) using seed-to-voxel analyses.
View Article and Find Full Text PDFMigraine is a pain disorder associated with abnormal brain structure and function, yet the effect of migraine on acute pain processing remains unclear. It also remains unclear whether altered pain-related brain responses and related structural changes are associated with clinical migraine characteristics. Using fMRI and three levels of thermal stimuli (non-painful, mildly painful, and moderately painful), we compared whole-brain activity between 14 migraine patients and 14 matched controls.
View Article and Find Full Text PDFWe used functional MRI and a longitudinal design to investigate the brain mechanisms in a previously reported estrogen-dependent visceral hypersensitivity model. We hypothesized that noxious visceral stimulation would be associated with activation of the insula, anterior cingulate cortex, and amygdala, and that estrogen-dependent, stress-induced visceral hypersensitivity would both enhance activation of these regions and recruit activation of other brain areas mediating affect and reward processing. Ovariectomized rats were treated with estrogen (17 β-estradiol, E2) or vehicle (n = 5 per group) and scanned in a 7T MRI at three different time points: pre-stress (baseline), 2 days post-stress, and 18 days post-stress.
View Article and Find Full Text PDFIrritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder of unknown etiology. Although relatively common in children, how this condition affects brain structure and function in a pediatric population remains unclear. Here, we investigate brain changes in adolescents with IBS and healthy controls.
View Article and Find Full Text PDFTo investigate the neuroanatomical and functional brain changes in migraine patients relative to healthy controls, we used a combined analytical approach including voxel- and surface-based morphometry along with resting-state functional connectivity to determine whether areas showing structural alterations in patients also showed abnormal functional connectivity. Additionally, we wanted to assess whether these structural and functional changes were associated with group differences in pain catastrophizing and migraine-related disease variables in patients. We acquired T1-weighted anatomical and functional magnetic resonance imaging scans during rest in human subjects with a diagnosis of migraine and healthy controls.
View Article and Find Full Text PDFLittle is known about the effect of migraine on neural cognitive networks. However, cognitive dysfunction is increasingly being recognized as a comorbidity of chronic pain. Pain appears to affect cognitive ability and the function of cognitive networks over time, and decrements in cognitive function can exacerbate affective and sensory components of pain.
View Article and Find Full Text PDFIn rough-skinned newts, Taricha granulosa, exposure to an acute stressor results in the rapid release of corticosterone (CORT), which suppresses the ability of vasotocin (VT) to enhance clasping behavior. CORT also suppresses VT-induced spontaneous activity and sensory responsiveness of clasp-controlling neurons in the rostromedial reticular formation (Rf). The cellular mechanisms underlying this interaction remain unclear.
View Article and Find Full Text PDFPeripheral neuropathy often manifests clinically with symptoms of mechanical and cold allodynia. However, the neuroplastic changes associated with peripheral neuropathic pain and the onset and progression of allodynic symptoms remain unclear. Here, we used a chronic neuropathic pain model (spared nerve injury; SNI) to examine functional and metabolic brain changes associated with the development and maintenance of mechanical and cold hypersensitivity, the latter which we assessed both behaviorally and during a novel acetone application paradigm using functional MRI (fMRI).
View Article and Find Full Text PDFBackground & Aims: Alterations in central corticotropin-releasing factor signaling pathways have been implicated in the pathophysiology of anxiety disorders and irritable bowel syndrome (IBS). We aimed to characterize the effects of the corticotropin-releasing factor receptor 1 (CRF-R1) antagonist, GW876008, on brain and skin conductance responses during acquisition and extinction of conditioned fear to the threat of abdominal pain in subjects with IBS and healthy individuals (controls).
Methods: We performed a single-center, randomized, double-blind, 3-period crossover study of 11 women with IBS (35.
Central administration of corticotropin-releasing hormone (CRH) is known to enhance locomotion across a wide range of vertebrates, including the roughskin newt, Taricha granulosa. The present study aimed to identify the CRH effects on locomotor-controlling medullary neurons that underlie the peptide's behavioral stimulating actions. Single neurons were recorded from the rostral medullary reticular formation before and after intraventricular infusion of CRH in freely behaving newts and newts paralyzed with a myoneural blocking agent.
View Article and Find Full Text PDFAlterations in corticotropin-releasing factor (CRF) signaling pathways have been implicated in irritable bowel syndrome (IBS) pathophysiology. We aimed to (1) determine the effect of the selective CRF receptor 1 antagonist (CRF(1)) GW876008 relative to placebo, on regional activation and effective connectivity of a stress-related emotional-arousal circuit during expectation of abdominal pain using functional magnetic resonance imaging in human subjects with a diagnosis of IBS and healthy controls (HCs), and (2) examine GW876008 effects on state-trait anxiety and hypothalamic-pituitary-adrenal (HPA) axis response. Although there were no drug-related effects on peripheral HPA activity, significant central effects were observed in brain regions associated with the stress response.
View Article and Find Full Text PDFThe present study examined whether a moderately aversive abdominal threat would lead to greater enhancement in affect- and pain-related defensive responding as indexed by the acoustic startle reflex (ASR) and nociceptive flexion reflex (NFR) in women compared to men. We also predicted sex differences in threat-related autonomic arousal measured by skin conductance responses (SCRs) to acoustic startle and noxious sural nerve stimulation. Unpredictable threat was manipulated by alternating 30-second safe ("no abdominal stimulation will be given") and threat ("abdominal stimulation may occur at anytime") periods.
View Article and Find Full Text PDFPurpose: Altered sensory processing in interstitial cystitis/painful bladder syndrome cases may result from a deficiency of the central nervous system to adequately filter incoming visceral afferent information. We used prepulse inhibition as an operational measure of sensorimotor gating to examine early pre-attentive stages of information processing in females with interstitial cystitis/painful bladder syndrome and healthy controls.
Materials And Methods: We assessed prepulse inhibition in 14 female patients with interstitial cystitis/painful bladder syndrome and 17 healthy controls at 60 and 120-millisecond prepulse-to-startle stimulus intervals.