Brain activity during Stroop task performance at age 74 after exposure to the Dutch famine during early gestation.

OBJECTIVE: Poorer performance on the Stroop task has been reported after prenatal famine exposure at age 58, potentially indicating cognitive decline. We investigated whether brain activation during Stroop task performance at age 74 differed between individuals exposed to famine prenatally, individuals born before and individuals conceived after the famine. METHOD: In the Dutch famine birth cohort, we performed a Stroop task fMRI study of individuals exposed (n = 22) or unexposed (born before (n = 18) or conceived after (n = 25)) to famine in early gestation. We studied group differences in task-related mean activation of the dorsolateral prefrontal cortex (DLPFC), anterior cingulate cortex (ACC) and posterior parietal cortex (PPC). Additionally, we explored potential disconnectivity of the DLPFC using psychophysiological interaction analysis. RESULTS: We observed similar activation patterns in the DLPFC, ACC and PPC in individuals born before and individuals exposed to famine, while individuals conceived after famine had generally higher activation patterns. However, activation patterns were not significantly different between groups. Task-related decreases in connectivity were observed between left DLPFC-left PPC and right DLPFC-right PPC, but were not significantly different between groups. CONCLUSIONS: Although not statistically significant, the observed patterns of activation may reflect a combined effect of general brain aging and prenatal famine exposure.

Brain processing of rectal sensation in adolescents with functional defecation disorders and healthy controls.

BACKGROUND: Decreased sensation of urge to defecate is often reported by children with functional constipation (FC) and functional nonretentive fecal incontinence (FNRFI). The aim of this cross-sectional study was to evaluate cerebral activity in response to rectal distension in adolescents with FC and FNRFI compared with healthy controls (HCs). METHODS: We included 15 adolescents with FC, 10 adolescents with FNRFI, and 15 young adult HCs. Rectal barostat was performed prior to functional magnetic resonance imaging (fMRI) to determine individual pressure thresholds for urge sensation. Subjects received 2 sessions of 5 × 30 seconds of barostat stimulation during the acquisition of blood oxygenation level-dependent fMRI. Functional magnetic resonance imaging signal differences were analyzed using SPM8 in Matlab. KEY RESULTS: Functional constipation and FNRFI patients had higher thresholds for urgency than HCs (P < .001). During rectal distension, FC patients showed activation in the anterior cingulate cortex, dorsolateral prefrontal cortex, inferior parietal lobule, and putamen. No activations were observed in controls and FNRFI patients. Functional nonretentive fecal incontinence patients showed deactivation in the hippocampus, parahippocampal gyrus, fusiform gyrus (FFG), lingual gyrus, posterior parietal cortex, and precentral gyrus. In HCs, deactivated areas were detected in the hippocampus, amygdala, FFG, insula, thalamus, precuneus, and primary somatosensory cortex. In contrast, no regions with significant deactivation were detected in FC patients. CONCLUSIONS & INFERENCES: Children with FC differ from children with FNRFI and HCs with respect to patterns of cerebral activation and deactivation during rectal distension. Functional nonretentive fecal incontinence patients seem to resemble HCs when it comes to brain processing of rectal distension.

Cerebral Perfusion Measurements in Elderly with Hypertension Using Arterial Spin Labeling.

PURPOSE: The current study assesses the feasibility and value of crushed cerebral blood flow (CBFcrushed) and arterial transit time (ATT) estimations for large clinical imaging studies in elderly with hypertension. MATERIAL AND METHODS: Two pseudo-continuous arterial spin labeling (ASL) scans with (CBFcrushed) and without flow crushers (CBFnon-crushed) were performed in 186 elderly with hypertension, from which CBF and ATT maps were calculated. Standard flow territory maps were subdivided into proximal, intermediate and distal flow territories, based on the measured ATT. The coefficient of variation (CV) and physiological correlations with age and gender were compared between the three perfusion parameters. RESULTS: There was no difference in CV between CBFcrushed and CBFnon-crushed (15-24%, p>0.4) but the CV of ATT (4-9%) was much smaller. The total gray matter correlations with age and gender were most significant with ATT (p = .016 and p<.001 respectively), in between for CBFcrushed (p = .206 and p = .019) and least significant for CBFnon-crushed (p = .236 and p = .100). CONCLUSION: These data show the feasibility and added value of combined measurements of both crushed CBF and ATT for group analyses in elderly with hypertension. The obtained flow territories provide knowledge on vascular anatomy of elderly with hypertension and can be used in future studies to investigate regional vascular effects.

Early life adversities and adolescent antisocial behavior: The role of cardiac autonomic nervous system reactivity in the TRAILS study.

In the current study, the role of pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA) was studied in the association between prior adversities and antisocial behavior in adolescence. PEP and RSA task reactivity and recovery to a public speaking task were assessed in adolescents from a longitudinal population-based study (N=624, Mage=16.14 years, 49.2% boys). Perinatal adversities were unrelated to antisocial behavior, but experiencing more stressful adversities between age 0 and 15 was associated with antisocial behavior at age 16 in boys with blunted PEP reactivity and smaller PEP differences from rest to recovery. Number of adversities between age 0 and 15 was associated with antisocial behavior in boys with blunted and girls with heightened RSA reactivity and larger PEP differences from rest to recovery. The association between prior adversities and antisocial behavior were small in effect size and depended upon sex and PEP and RSA reactivity and recovery.

Brain reward-system activation in response to anticipation and consumption of palatable food is altered by glucagon-like peptide-1 receptor activation in humans.

AIM: To test the hypothesis that food intake reduction after glucagon-like peptide-1 (GLP-1) receptor activation is mediated through brain areas regulating anticipatory and consummatory food reward. METHODS: As part of a larger study, we determined the effects of GLP-1 receptor activation on brain responses to anticipation and receipt of chocolate milk versus a tasteless solution, using functional MRI (fMRI). Obese subjects with type 2 diabetes, and obese and lean subjects with normoglycaemia (n = 48) underwent three fMRI sessions at separate visits with intravenous infusion of the GLP-1 receptor agonist exenatide, exenatide with prior GLP-1 receptor blockade by exendin-9-39 or placebo, during somatostatin pituitary-pancreatic clamps. RESULTS: Body mass index negatively correlated with brain responses to receipt of chocolate milk and positively correlated with anticipation of receipt of chocolate milk in brain areas regulating reward, appetite and motivation. Exenatide increased brain responses to receipt of chocolate milk and decreased anticipation of receipt of chocolate milk compared with placebo, paralleled by reductions in food intake. Exendin-9-39 largely prevented these effects. CONCLUSIONS: Our findings show that GLP-1 receptor activation decreases anticipatory food reward, which may reduce cravings for food and increases consummatory food reward, which may prevent overeating.

Rhythmic finger tapping reveals cerebellar dysfunction in essential tremor.

INTRODUCTION: Cerebellar circuits are hypothesized to play a central role in the pathogenesis of essential tremor. Rhythmic finger tapping is known to strongly engage the cerebellar motor circuitry. We characterize cerebellar and, more specifically, dentate nucleus function, and neural correlates of cerebellar output in essential tremor during rhythmic finger tapping employing functional MRI. METHODS: Thirty-one propranolol-sensitive essential tremor patients with upper limb tremor and 29 healthy controls were measured. T2*-weighted EPI sequences were acquired. The task consisted of alternating rest and finger tapping blocks. A whole-brain and region-of-interest analysis was performed, the latter focusing on the cerebellar cortex, dentate nucleus and inferior olive nucleus. Activations were also related to tremor severity. RESULTS: In patients, dentate activation correlated positively with tremor severity as measured by the tremor rating scale part A. Patients had reduced activation in widespread cerebellar cortical regions, and additionally in the inferior olive nucleus, and parietal and frontal cortex, compared to controls. CONCLUSION: The increase in dentate activation with tremor severity supports involvement of the dentate nucleus in essential tremor. Cortical and cerebellar changes during a motor timing task in essential tremor might point to widespread changes in cerebellar output in essential tremor.

Functional MR imaging on an open 1T MR imaging system: exploiting the advantages of an open MR imaging system for functional MR imaging.

BACKGROUND AND PURPOSE: Open MR imaging scanners are designed for imaging of specific patient groups that cannot be routinely scanned with conventional MR imaging scanners (eg, patients with obesity and claustrophobia). This study aims to determine whether BOLD sensitivity on an open 1T scanner is adequate for fMRI for diagnostic and research purposes by directly comparing fMRI results with a standard 3T MR imaging scanner. The optimal TE was also determined. MATERIALS AND METHODS: Twelve healthy adults were scanned by using both an open 1T scanner and a standard 3T scanner. Gradient-echo echo-planar images were acquired for all subjects while performing motor and affective paradigms, each at 5 different TEs per scanner (range, 40-80 ms at open 1T; 20-40 ms at 3T). To compare BOLD sensitivity between scanners and TEs, we determined maximum statistical t scores per TE for all relevant brain areas (motor cortex, visual cortex, amygdala, and OFC) for individual subjects and group analyses. Additionally, T2* values were determined per scanner for the relevant brain areas. RESULTS: Maximum t scores were significantly lower in the relevant brain areas on the open 1T compared with the 3T for single subjects but not for group analyses. The optimal TE for fMRI on an open 1T MR imaging system was found to be approximately 70 ms. CONCLUSIONS: Although for single-subject studies as used in diagnostics, 3T was found to be superior, fMRI on an open 1T MR imaging scanner is suitable for research designed to analyze data at a group level.