Neurofunctional characteristics of executive control in older people with HIV infection: a comparison with Parkinson's disease.

Expression of executive dysfunctions is marked by substantial heterogeneity in people living with HIV infection (PLWH) and attributed to neuropathological degradation of frontostriatal circuitry with age and disease. We compared the neurophysiology of executive function in older PLWH and Parkinson's disease (PD), both affecting frontostriatal systems. Thirty-one older PLWH, 35 individuals with PD, and 28 older healthy controls underwent executive task-activated fMRI, neuropsychological testing, and a clinical motor exam.

Alterations of Brain Signal Oscillations in Older Individuals with HIV Infection and Parkinson's Disease.

More than 30 years after the human immunodeficiency virus (HIV) epidemic, HIV patients are now aging due to the advances of antiretroviral therapy. With immunosenescence and the susceptibility of dopamine-rich basal ganglia regions to HIV-related injury, older HIV patients may show neurofunctional deficits similar to patients with Parkinson's disease (PD). We examined the amplitudes of low frequency fluctuations (ALFF) across different frequency bands of the BOLD signal in 30 older HIV-infected individuals, 33 older healthy controls, and 36 PD patients.

Effects of age, sex, and puberty on neural efficiency of cognitive and motor control in adolescents.

Critical changes in adolescence involve brain cognitive maturation of inhibitory control processes that are essential for a myriad of adult functions. Cognitive control advances into adulthood as there is more flexible integration of component processes, including inhibitory control of conflicting information, overwriting inappropriate response tendencies, and amplifying relevant responses for accurate execution. Using a modified Stroop task with fMRI, we investigated the effects of age, sex, and puberty on brain functional correlates of cognitive and motor control in 87 boys and 91 girls across the adolescent age range.

Phases of procedural learning and memory: characterisation with perceptual-motor sequence tasks.

Procedural learning and memory has been conceptualised as consisting of cognitive and autonomous phases. Although the Serial Reaction Time Task (SRTT) is a popular task used to study procedural memory (PM), it has not been used to explore the different phases of PM. The present study employed a modified SRTT and investigated whether it can distinguish phases of PM.

Aberrant blood-oxygen-level-dependent signal oscillations across frequency bands characterize the alcoholic brain.

Chronic alcoholism is associated with widespread regional differences from controls in brain activity and connectivity dynamics measured by blood-oxygen-level-dependent (BOLD) signals. Identification of alcoholism-related neurofunctional power dynamics using functional magnetic resonance imaging (fMRI) that relate to cognition and behavior may serve as biomarkers of alcoholism. Previously, resting-state fMRI studies examined BOLD signals at a single low-frequency (LF) bandwidth.

Sex-based differences in brain alterations across chronic pain conditions.

Common brain mechanisms are thought to play a significant role across a multitude of chronic pain syndromes. In addition, there is strong evidence for the existence of sex differences in the prevalence of chronic pain and in the neurobiology of pain. Thus, it is important to consider sex when developing general principals of pain neurobiology.

Placebo analgesia: Self-report measures and preliminary evidence of cortical dopamine release associated with placebo response.

Placebo analgesia is measured by self-report, yet current, expected, and recalled efficacy may be differentially related to brain function. Here we used a human thermal pain model to compare self-reports of expected, concurrent, and recalled efficacy of a topical placebo analgesic, and tested associations of the three measures of efficacy with changes in dopamine D2/D3 receptor availability in brain using [(18)F]fallypride with positron emission tomography (PET). Participants (15 healthy women) were assessed on three test days.

Multivariate morphological brain signatures predict patients with chronic abdominal pain from healthy control subjects.

Irritable bowel syndrome (IBS) is the most common chronic visceral pain disorder. The pathophysiology of IBS is incompletely understood; however, evidence strongly suggests dysregulation of the brain-gut axis. The aim of this study was to apply multivariate pattern analysis to identify an IBS-related morphometric brain signature that could serve as a central biological marker and provide new mechanistic insights into the pathophysiology of IBS.

Imaging brain mechanisms in chronic visceral pain.

Chronic visceral pain syndromes are important clinical problems with largely unmet medical needs. Based on the common overlap with other chronic disorders of visceral or somatic pain, mood and affect, and their responsiveness to centrally targeted treatments, an important role of central nervous system in their pathophysiology is likely. A growing number of brain imaging studies in irritable bowel syndrome, functional dyspepsia, and bladder pain syndrome/interstitial cystitis has identified abnormalities in evoked brain responses, resting state activity, and connectivity, as well as in gray and white matter properties.

Sex and disease-related alterations of anterior insula functional connectivity in chronic abdominal pain.

Resting-state functional magnetic resonance imaging has been used to investigate intrinsic brain connectivity in healthy subjects and patients with chronic pain. Sex-related differences in the frequency power distribution within the human insula (INS), a brain region involved in the integration of interoceptive, affective, and cognitive influences, have been reported. Here we aimed to test sex and disease-related alterations in the intrinsic functional connectivity of the dorsal anterior INS.

Early adverse life events and resting state neural networks in patients with chronic abdominal pain: evidence for sex differences.

Background: Early adverse life events (EALs) and sex have been identified as vulnerability factors for the development of several stress-sensitive disorders, including irritable bowel syndrome (IBS). We aimed to identify disease and sex-based differences in resting state (RS) connectivity associated with EALs in individuals with IBS.

Method: A history of EALs before age 18 years was assessed using the early trauma inventory.

Regional neuroplastic brain changes in patients with chronic inflammatory and non-inflammatory visceral pain.

Regional cortical thickness alterations have been reported in many chronic inflammatory and painful conditions, including inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS), even though the mechanisms underlying such neuroplastic changes remain poorly understood. In order to better understand the mechanisms contributing to grey matter changes, the current study sought to identify the differences in regional alterations in cortical thickness between healthy controls and two chronic visceral pain syndromes, with and without chronic gut inflammation. 41 healthy controls, 11 IBS subjects with diarrhea, and 16 subjects with ulcerative colitis (UC) underwent high-resolution T1-weighted magnetization-prepared rapid acquisition gradient echo scans.

Irritable bowel syndrome in female patients is associated with alterations in structural brain networks.

Alterations in gray matter (GM) density/volume and cortical thickness (CT) have been demonstrated in small and heterogeneous samples of subjects with differing chronic pain syndromes, including irritable bowel syndrome (IBS). Aggregating across 7 structural neuroimaging studies conducted at University of California, Los Angeles, Los Angeles, CA, USA, between August 2006 and April 2011, we examined group differences in regional GM volume in 201 predominantly premenopausal female subjects (82 IBS, mean age: 32±10 SD, 119 healthy controls [HCs], 30±10 SD). Applying graph theoretical methods and controlling for total brain volume, global and regional properties of large-scale structural brain networks were compared between the group with IBS and the HC group.

Sex-related differences of cortical thickness in patients with chronic abdominal pain.

Background & Aims: Regional reductions in gray matter (GM) have been reported in several chronic somatic and visceral pain conditions, including irritable bowel syndrome (IBS) and chronic pancreatitis. Reported GM reductions include insular and anterior cingulate cortices, even though subregions are generally not specified. The majority of published studies suffer from limited sample size, heterogeneity of populations, and lack of analyses for sex differences.

Patients with chronic visceral pain show sex-related alterations in intrinsic oscillations of the resting brain.

Abnormal responses of the brain to delivered and expected aversive gut stimuli have been implicated in the pathophysiology of irritable bowel syndrome (IBS), a visceral pain syndrome occurring more commonly in women. Task-free resting-state functional magnetic resonance imaging (fMRI) can provide information about the dynamics of brain activity that may be involved in altered processing and/or modulation of visceral afferent signals. Fractional amplitude of low-frequency fluctuation is a measure of the power spectrum intensity of spontaneous brain oscillations.

Global and regional alterations of hippocampal anatomy in long-term meditation practitioners.

Studies linking meditation and brain structure are still relatively sparse, but the hippocampus is consistently implicated as one of the structures altered in meditation practitioners. To explore hippocampal features in the framework of meditation, we analyzed high-resolution structural magnetic resonance imaging data from 30 long-term meditators and 30 controls, closely matched for sex, age, and handedness. Hippocampal formations were manually traced following established protocols.