Ravi R. Bhatt

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Verified

Ravi verified their affiliation via an institutional email.

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• PhD
• Postdoctoral Scholar - Research Associate at University of Southern California

Chronic pain is a major public health problem in the United States costing $635 billion annually. Hospitalizations for chronic pain in childhood have increased almost tenfold in the past decade, without breakthroughs in novel treatment strategies. Findings from brain imaging studies using structural and resting-state fMRI could potentially help per...

Irritable bowel syndrome (IBS) is a common disorder of brain-gut interactions characterized by chronic abdominal pain, altered bowel movements, often accompanied by somatic and psychiatric comorbidities. We aimed to test the hypothesis that a baseline phenotype composed of multi-modal neuroimaging and clinical features predicts clinical improvement...

Introduction Chronic pain (CP) in adolescents costs society $19.5 billion annually. Childhood hospital admissions for CP increased 831% from 2004-2010. Many have comorbid conditions, such as depression, anxiety, and change in bowel habits; a large proportion will continue to experience CP into adulthood4. Central sensitization (CS), possibly indic...

Irritable bowel syndrome (IBS) is the most prevalent disorder of brain-gut interactions that affects between 5 and 10% of the general population worldwide. The current symptom criteria restrict the diagnosis to recurrent abdominal pain associated with altered bowel habits, but the majority of patients also report non-painful abdominal discomfort, a...

Background Chronic pain affects nearly 20% of the US population. It is a leading cause of disability globally, and associated with a heightened risk for suicide. The role of the central nervous system in the perception and maintenance of chronic pain has recently been accepted, but specific brain circuitries involved have yet to be mapped across p...

While it has been suggested that alterations in the composition of gut microbial metabolites may play a causative role in the pathophysiology of autism spectrum disorder (ASD), it is not known how gut microbial metabolites are associated with ASD-specific brain alterations. In this cross-sectional, case-control observational study, (i) fecal metabo...

Over one-third of patients with chronic pain report pain at multiple anatomical sites. The current study examined the co-localization of pain and its intensity over a 2-year follow-up period. Kendall rank correlation coefficient (denoted as tau) was applied for the co-occurrence of pain in specific locations. Individuals over the age of 60 years we...

Peak width of skeletonized mean diffusivity (PSMD) is an emerging automated diffusion imaging marker showing clinically relevant changes in cerebral small vessel disease (cSVD), a leading cause of stroke and dementia with no mechanism-based treatment. We conducted a genome-wide association study of PSMD in 58,403 participants from 24 population-bas...

Chronic pain is the leading cause of disability and disease burden globally. It represents a complex set of conditions where a biopsychosocial approach is needed for a comprehensive mechanistic understanding and treatment. This dissertation explores the multifaceted underpinnings of chronic pain through a combination of clinical, neuroimaging, and...

The corpus callosum (CC) is the largest set of white matter fibers connecting the two hemispheres of the brain. In humans, it is essential for coordinating sensorimotor responses, performing associative/executive functions, and representing information in multiple dimensions. Understanding which genetic variants underpin corpus callosum morphometry...

Introduction: The choroid plexus (CP) is a highly vascularized tissue in the brain ventricles and is the principal source of cerebrospinal fluid, functioning as the blood-CSF barrier, and a gateway for immune cell entry into the CNS. The underlying mechanism of CP calcification (CPcal) is uncertain, but it is associated with aging and neurological...

Obesity contributes to physical comorbidities and mental health consequences. We explored whether physical activity could influence more than metabolic regulation and result in psychological benefits through the brain-gut microbiome (BGM) system in a population with high BMI. Fecal samples were obtained for 16 s rRNA profiling and fecal metabolomic...

Structural alterations of the midsagittal corpus callosum (midCC) have been associated with a wide range of brain disorders. The midCC is visible on most MRI contrasts and in many acquisitions with a limited field-of-view. Here, we present an automated tool for segmenting and assessing the shape of the midCC from T1w, T2w, and FLAIR images. We trai...

Structural alterations of the midsagittal corpus callosum (midCC) have been associated with a wide range of brain disorders. The midCC is visible on most MRI contrasts and in many acquisitions with a limited field-of-view. Here, we present an automated tool for segmenting and assessing the shape of the midCC from T1w, T2w, and FLAIR images. We trai...

In brain imaging research, it is becoming standard practice to remove the face from the individual′s 3D structural MRI scan to ensure data privacy standards are met. Face removal – or ′defacing′ – is being advocated for large, multi– site studies where data is transferred across geographically diverse sites. Several methods have been developed to l...

Investigating sex as a biological variable is key to determine obesity manifestation and treatment response. Individual neuroimaging modalities have uncovered mechanisms related to obesity and altered ingestive behaviors. However, few, if any, studies have integrated data from multimodal brain imaging to predict sex-specific brain signatures relate...

Neuroticism is one of the most robust risk factors for addictive behaviors including food addiction (a key contributor to obesity), although the associated mechanisms are not well understood. A transdiagnostic approach was used to identify the neuroticism-related neuropsychological and gut metabolomic patterns associated with food addiction. Predic...

The populations of the Middle East and North Africa countries (MENA) are predicted to contribute to the world’s sharpest increases in rates of Alzheimer’s disease and related dementias (ADRD) in the coming years (GBD 2022), yet this group is underrepresented in health studies. The UK Biobank provides one of the largest and well‐characterized datase...

Alterations of the brain-gut-microbiome system (BGM) have been implicated in the pathophysiology of irritable bowel syndrome (IBS), yet bowel habit-specific alterations have not been elucidated. In this cross-sectional study, we apply a systems biology approach to characterize BGM patterns related to predominant bowel habit. Fecal samples and resti...

Automatic neuroimaging processing tools provide convenient and systematic methods for extracting features from brain magnetic resonance imaging scans. One tool, FreeSurfer, provides an easy-to-use pipeline to extract cortical and subcortical morphometric measures. There have been over 25 stable releases of FreeSurfer, with different versions used a...

The neurobiological bases of the association between development and psychopathology remain poorly understood. Here, we identify a shared spatial pattern of cortical thickness (CT) in normative development and several psychiatric and neurological disorders. Principal component analysis (PCA) was applied to CT of 68 regions in the Desikan-Killiany a...

Obesity contributes to physical comorbidities and mental health consequences. We explored whether physical activity could influence more than metabolic regulation and result in psychological benefits through the brain-gut microbiome (BGM) system in a population with high BMI. Fecal samples were obtained for 16s rRNA profiling and fecal metabolomics...

Background: Chronic pain is a global health priority. Mapping pain occurring at different body sites, and variability in brain circuitry related to widespread chronic pain, can elucidate nuanced roles of the central nervous system underlying chronic pain conditions. Chronic pain triples suicide risk; however, whether brain circuitry can inform this...

Automatic neuroimaging segmentation and parcellation tools provide convenient and systematic methods for extracting numerous features from brain MRI scans, and are becoming standard practice for large-scale coordinated studies. One such tool, FreeSurfer, provides an easy-to-use pipeline to extract metrics describing cortical and subcortical morphom...

Despite recent advances, there is still a major need to better understand the interactions between brain function and chronic gut inflammation and its clinical implications. Alterations in executive function have previously been identified in several chronic inflammatory conditions, including inflammatory bowel diseases. Inflammation-associated bra...

Background Anorexia nervosa (AN) is a disorder characterized by an incapacitating fear of weight gain and by a disturbance in the way the body is experienced, facets that motivate dangerous weight loss behaviors. Multimodal neuroimaging studies highlight atypical neural activity in brain networks involved in interoceptive awareness and reward proce...

Background There is growing recognition that bidirectional signaling between the digestive tract and the brain contributes to irritable bowel syndrome (IBS). We recently showed in a large randomized controlled trial that cognitive behavioral therapy (CBT) reduces IBS symptom severity. This study investigated whether baseline brain and gut microbiom...

Background: While neuroimaging has uncovered mechanisms causing altered ingestive behaviors, few studies have integrated data from multimodal brain imaging to predict sex-specific brain signatures in individuals with obesity. A data-driven approach was used to uncover a correlated signature between differential brain phenotypes and clinical data th...

Background Anorexia nervosa (AN) is a disorder characterized by an incapacitating fear of weight gain and by a disturbance in the way the body is experienced, facets that motivate dangerous weight loss behaviors. Multimodal neuroimaging studies highlight atypical neural activity in brain networks involved in interoceptive awareness and reward proce...

Introduction Chronic pain (CP) has a severe impact on quality of life, and is the leading cause of disability and disease burden globally. The central nervous system plays a key role in the development and maintenance of CP, but pain remains self-reported and there are no clear biomarkers to assess CP. Large highly-powered studies are needed. We ai...

Background Chronic pain (CP) affects over 100 million Americans, has severe impacts on quality of life, and has great economic burden. The CNS is involved in the development of chronic pain, but no well-powered structural neuroimaging studies have been conducted. Methods We tested which cortical and subcortical structures are associated with CP,...

Alterations in the brain-gut system have been implicated in various disease states, but little is known about how early-life adversity (ELA) impacts development and adult health as mediated by brain-gut interactions. We hypothesize that ELA disrupts components of the brain-gut system, thereby increasing susceptibility to disordered mood. In a sampl...

Objective: We aimed to identify differences in network properties of white matter microstructure between asymptomatic ulcerative colitis (UC) participants who had a history of chronic gut inflammation, healthy controls (HCs) and a disease control group without gut inflammation (irritable bowel syndrome; IBS). Design: Diffusion weighted imaging was...

Abstract Functional neuroimaging studies in obesity have identified alterations in the connectivity within the reward network leading to decreased homeostatic control of ingestive behavior. However, the neural mechanisms underlying sex differences in the prevalence of food addiction in obesity is unknown. The aim of the study was to identify functi...

Background: Bariatric surgery is proven to change eating behavior and cause sustained weight loss, yet the exact mechanisms underlying these changes are not clearly understood. We explore this in a novel way by examining how bariatric surgery affects the brain-gut-microbiome (BGM) axis. Methods: Patient demographics, serum, stool, eating behavio...

Background: Neuroimaging studies have identified obesity-related differences in the brain's resting state activity. An imbalance between homeostatic and reward aspects of ingestive behaviour may contribute to obesity and food addiction. The interactions between early life adversity (ELA), the reward network and food addiction were investigated to...

Pain is a highly complex and individualized experience with biopsychosocial components. Neuroimaging research has shown evidence of the involvement of the central nervous system in the development and maintenance of chronic pain conditions, including urological chronic pelvic pain syndrome (UCPPS). Furthermore, a history of early adverse life event...

Multimodal neuroimaging studies provide support for a role of alterations in sensory processing circuits and endogenous pain modulatory systems in provoked vestibulodynia (PVD). In this study we tested the hypotheses that PVD compared to healthy controls (HCs) would demonstrate gray matter volume (GMV) alterations in regions associated with sensori...

Objective: Imaging studies in adults with irritable bowel syndrome (IBS) have shown both morphological and resting state (RS) functional connectivity (FC) alterations related to cortical modulation of sensory processing. Because analogous differences have not been adequately investigated in children, this study compared gray matter volume (GMV) an...

Highlights • Patients with sickle-cell disease (SCD) have greater resting-state functional connectivity between the locus coeruleus (LC) and dorsolateral prefrontal cortex (dlPFC). • Patients with SCD have greater resting state centrality of the LC • SCD patients with chronic pain exhibited even greater functional connectivity between the LC and dl...

Aim of the Investigation: The presence of widespread pain has been hypothesized to reflect a distinct phenotype of general hypersensitivity related to ‘centralization’. Recently, decreased cutaneous heat pain and pressure pain thresholds were reported in patients with chronic lower back pain with widespread pain compared to that in patients with lo...

Aim: Sickle Cell Disease (SCD) is a genetic disorder associated with anemia and repeated painful vaso-occlusive crises that can develop into chronic pain via central sensitization. Recent rodent models have shown hyperactivity in projections from neurons in the LC to the medial prefrontal cortex (mPFC) in response to repeated noxious input can lead...

Investigation of central processes in localized provoked vulvodynia (PVD) suggest altered central sensory processing and modulation, including central sensitization and dysregulation of endogenous pain modulatory systems. The aim of the present study was to (1) determine alterations in regional gray matter (GM) volumes in PVD compared to healthy co...

Vaso-occlusive pain crises are the “hallmark” of sickle cell disease (SCD). SCD patients have a high incidence of chronic pain thought to develop via central sensitization. Research in rodents has shown that locus coeruleus (LC) function in pain regulation shifts from a pain inhibitory to a facilitative effect after exposure to continuous nocicepti...

Objective: This study aimed to characterize obesity-related sex differences in the intrinsic activity and connectivity of the brain's reward networks. Methods: Eighty-six women (n = 43) and men (n = 43) completed a 10-minute resting functional magnetic resonance imaging scan. Sex differences and commonalities in BMI-related frequency power distr...

Supplementary Table 1: Differences in network metrics using alternative weighting methods Groups: High BMI (BMI≥25), Normal BMI (BMI<25) Abbreviations: BMI, body mass index. KEY: X denotes significant results of the ordinary least squares analysis model applied to test the differences in centrality in brain ROIs based upon subject groups defines by...

Background Vaso-occlusive pain crises (VOCs) are the “hallmark” of sickle-cell disease (SCD) and can lead to sympathetic nervous system dysfunction. Increased sympathetic nervous system activation during VOCs and/or pain can result in vasoconstriction, which may increase the risk for subsequent VOCs and pain. Hypnosis is a neuromodulatory intervent...

Background: Irritable Bowel Syndrome (IBS) is a brain-gut disorder characterized by abdominal pain that is associated with altered bowel habits. IBS patients have functional brain alterations in regions associated with salience and emotional processing. (1) Mind-body interventions, such as hypnosis, cognitive behavioral therapy and Mindfulness Base...

Purpose: We exposed premature infants to womb-like sounds to evaluate such exposure on breathing and cardiovascular patterns. We hypothesized that these sounds would reduce apnea and intermittent hypoxemia, enhance parasympathetic outflow, and improve cardiovascular patterns. Methods: A total of 20 cases and 5 control infants at ≤ 32–36 weeks corre...

Background/objectives: The brain has a central role in regulating ingestive behavior in obesity. Analogous to addiction behaviors, an imbalance in the processing of rewarding and salient stimuli results in maladaptive eating behaviors that override homeostatic needs. We performed network analysis based on graph theory to examine the association be...

Introduction: Vaso-occlusive pain crises are considered the "hallmark" of sickle cell disease (SCD). Persistent occurrence is thought to lead to changes in the peripheral and central nervous system, which can then in turn lead to changes in pain sensitivity. Imaging studies have shown that hypnotic analgesia can reduce activity in supraspinal areas...

Resilience is the ability to adequately adapt and respond to homeostatic perturbations. Although resilience has been associated with positive health outcomes, the neuro-biological basis of resilience is poorly understood. The aim of the study was to identify associations between regional brain morphology and trait resilience with a focus on resilie...

We hypothesized that premature infants exposed to womb-like sounds would show decreased apneic, hypoxemic, and bradycardic events. We believed these findings could be explained by the auditory system exerting influence over the autonomic system and potentially enhancing parasympathetic tone in neonates. Twenty premature infants without comorbiditie...

Individual differences in resting vagally mediated heart rate variability (vmHRV) have been associated with executive function in numerous laboratory studies. The Iowa Gambling Task (IGT) is designed to assess real world decision-making and has been studied extensively. Our group recently reported a relationship between resting vmHRV and IGT perfor...

Individual differences in pain perception have been well documented to factors such as age, gender, culture, and ethnicity. As the response to nociceptive stimuli involves activation of the sympathetic nervous system, physiological measures are used to observe changes in neural activity associated with pain perception and the autonomic nervous syst...

We have recently shown that heart rate variability (HRV), an index of executive function and inhibitory control, predicts better decision-making overtime within a judgment and decision-making (JDM) paradigm. Thus, inhibitory control, as indexed by HRV, seems to be a key mechanism in JDM situations. Additionally, it is posited that risk taking behav...

This Letter to the Editor reports findings from a randomized controlled cross-over trial, extending a previous study on the effects of music listening to reduce sensitivity to cold pain stimulation. Within this small replication, participants listened to music or white noise (compared to a silence condition) before nociceptive stimulation by the co...

Abstract This study set to evaluate the effectiveness of music listening in reducing acute pain resulting from the Cold Processor Task (CPT) in a healthy population. Heart rate variability (HRV) is used as a marker for autonomic nervous system functioning. Description Individual differences in HRV have been associated with the function of autonomi...

This study set to evaluate the effectiveness of music listening and listening to white noise in reducing acute pain resulting from the Cold Processor Task (CPT) in a healthy population. Heart rate variability (HRV) is used as a marker for autonomic nervous system functioning.

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