Prefrontal and posterior parietal contributions to the perceptual awareness of touch

Which brain regions contribute to the perceptual awareness of touch remains largely unclear. We collected structural magnetic resonance imaging scans and neurological examination reports of 70 patients with brain injuries or stroke in S1 extending into adjacent parietal, temporal or pre-/frontal regions. We applied voxel-based lesion-symptom mapping to identify brain areas that overlap with an impaired touch perception (i.e., hypoesthesia). As expected, patients with hypoesthesia (n = 43) presented lesions in all Brodmann areas in S1 on postcentral gyrus (BA 1, 2, 3a, 3b). At the anterior border to BA 3b, we additionally identified motor area BA 4p in association with hypoesthesia, as well as further ventrally the ventral premotor cortex (BA 6, BA 44), assumed to be involved in whole-body perception. At the posterior border to S1, we found hypoesthesia associated effects in attention-related areas such as the inferior parietal lobe and intraparietal sulcus. Downstream to S1, we replicated previously reported lesion-hypoesthesia associations in the parietal operculum and insular cortex (i.e., ventral pathway of somatosensory processing). The present findings extend this pathway from S1 to the insular cortex by prefrontal and posterior parietal areas involved in multisensory integration and attention processes

High resolution luminescence chronology of coastal dune deposits near Chumphon, Western Gulf of Thailand

The development of coastal dunes is linked to environmental controls such as sea-level variability, climatic conditions, and coastal morphology. Understanding the spatial and temporal variations of dunes is crucial for predicting how coastal landscapes may react to future climate changes and sea-level rise. However, there are very few detailed studies on the longer time-scale evolution (centennial to millennial) of coastal dunes from subtropical and tropical regions. Here, we combine a high-resolution luminescence chronology with sedimentological analyses to study the depositional history of a transverse coastal dune located within the Bang Berd dune field, Western Gulf of Thailand. While luminescence dating of uniform aeolian deposits is normally straight forward, we observe strong variations in the natural dose rate which are likely explained by the enrichment of accessory minerals in some laminae. Deposition of the dune started at least around 3000 years ago and coincides with a regional sea level drop. Sedimentary structures indicate deposition occurring predominantly in relation to the northeasterly winter monsoon. As the sea-level rise and increased storm intensity in the future may lead to stronger erosion along the coast, this study is highlighting the importance of the Bang Berd dune system as natural protection against coastal inundation

How we treat patients with leptomeningeal metastases

The goal of treatment of leptomeningeal metastasis is to improve survival and to maintain quality of life by delaying neurological deterioration. Tumour-specific therapeutic options in

A novel 2- and 3-choice touchscreen-based continuous trial-unique nonmatching-to-location task (cTUNL) sensitive to functional differences between dentate gyrus and CA3 subregions of the hippocampus.

RATIONALE: The touchscreen continuous trial-unique non-matching-to-location task (cTUNL) has been developed to optimise a battery of tasks under NEWMEDS (Novel Methods leading to New Medication in Depression and Schizophrenia, http://www.newmeds-europe.com ). It offers novel task features of both a practical and a theoretical nature compared to existing touchscreen tasks for spatial working memory. OBJECTIVES: The objective of this study was to determine whether the cTUNL task is sufficiently sensitive to differentiate between dentate gyrus (DG) and CA3 hippocampal subregion contributions to performance. METHODS: The effect of DG and CA3 dysfunction on memory for locations in the cTUNL task was tested. Rats were assessed on versions of the task-two-choice and three-choice-that differed in memory load. Performance was challenged using manipulations of delay and the spatial separation between target and sample locations. RESULTS: Dysfunction of the DG disrupts performance across both delay and spatial separations in two-choice cTUNL when the delay is variable and unpredictable. Increasing the working memory load (three stimuli) increases sensitivity to DG dysfunction, with deficits apparent at fixed, short delays. In contrast, CA3 dysfunction did not disrupt performance. CONCLUSION: Acquisition of cTUNL was rapid, and the task was sensitive to manipulations of delays and separations. A three-choice version of the task was found to be viable. Finally, both the two- and three-choice versions of the task were able to differentiate between limited dysfunction to different areas within the hippocampus. DG dysfunction affected performance when using unpredictable task parameters. CA3 dysfunction did not result in impairment, even at the longest delays tested.This work was supported by the Innovative Medicine Initiative Joint Undertaking under grant agreement no. 115008 of which resources are composed of EFPIA inkind contribution and financial contribution from the European Union’s Seventh Framework Programme (FP7/2007-2013). As part of this project, CAO was funded by Janssen Pharmaceuticals, Inc., of Johnson & Johnson.This is the author accepted manuscript. The final version is available from Springer via http://dx.doi.org/10.1007/s00213-015-4019-

Effect of Using Different Chemical Dispersing Agents in Grain Size Analyses of Fluvial Sediments via Laser Diffraction Spectrometry

Laser diffraction spectrometry allows for efficiently obtaining high-resolution grain size data. However, pretreatment and dispersion of aggregates in sediment samples are essential pre-requisites for acquiring accurate results using this method. This study evaluates the effectiveness of five dispersing agents in deflocculating the investigated fluvial sediments and the resulting grain size distribution obtained by laser diffraction spectrometry. We also examine the ability of the different dispersing agents to deflocculate sediment samples treated by thermal combustion. Distilled water presented a low efficiency in deflocculating the samples and yielded a near-zero clay content for samples with an expected clay content. The other chemical dispersants were effective in dispersing aggregates and yielding clay, albeit with different efficiencies. Calgon had the highest dispersing ability, followed closely by sodium tripolyphosphate. The performance of chemical treatment with sodium oxalate approaches that of sodium tripolyphosphate. However, it leads to the formation of precipitates in the samples, obscuring the actual grain size data. Sodium pyrophosphate derived the least amount of deflocculation among the four chemical dispersants. Furthermore, all the chemical dispersants were found to be ineffective in dispersing aggregates in samples treated by thermal combustion

Adiposity related brain plasticity induced by bariatric surgery

Previous magnetic resonance imaging (MRI) studies revealed structural-functional brain reorganization 12 months after gastric-bypass surgery, encompassing cortical and subcortical regions of all brain lobes as well as the cerebellum. Changes in the mean of cluster-wise gray/white matter density (GMD/WMD) were correlated with the individual loss of body mass index (BMI), rendering the BMI a potential marker of widespread surgery-induced brain plasticity. Here, we investigated voxel-by-voxel associations between surgery-induced changes in adiposity, metabolism and inflammation and markers of functional and structural neural plasticity. We re-visited the data of patients who underwent functional and structural MRI, 6 months (n = 27) and 12 months after surgery (n = 22), and computed voxel-wise regression analyses. Only the surgery-induced weight loss was significantly associated with brain plasticity, and this only for GMD changes. After 6 months, weight loss overlapped with altered GMD in the hypothalamus, the brain’s homeostatic control site, the lateral orbitofrontal cortex, assumed to host reward and gustatory processes, as well as abdominal representations in somatosensory cortex. After 12 months, weight loss scaled with GMD changes in right cerebellar lobule VII, involved in language-related/cognitive processes, and, by trend, with the striatum, assumed to underpin (food) reward. These findings suggest time-dependent and weight-loss related gray matter plasticity in brain regions involved in the control of eating, sensory processing and cognitive functioning

Gender balance and suitable positive actions to promote gender equality among healthcare professionals in neuro-oncology:The EANO positive action initiative

Background:The proportion of women among healthcare and biomedical research professionals in neuro-oncology is growing. With changes in cultural expectations and work-life balance considerations, more men aspire to nonfull-time jobs, yet, leadership positions remain dominated by men.Methods:The European Association of Neuro-Oncology (EANO) disparity committee carried out a digital survey to explore gender balance and actions suitable to promote gender equality. The survey was distributed among EANO members in 2021, with responses analyzed descriptively.Results:In total, 262 participants completed the survey (141 women, 53.8%; median age 43). Respondents were neurosurgeons (68, 26.0%); neurologists (67, 25.6%), medical oncologists (43, 16.4%), or other healthcare or research professionals; 208 participants (79.4%) worked full-time. Positive action to enforce the role of women in neuro-oncology was deemed necessary by 180 participants (68.7%), but only 28 participants (10.7%) agreed that women only should be promoted until gender balance is reached. A majority of respondents (162, 61.8%) felt that women with an equivalent CV should be prioritized over men to reach gender balance. If in the future the balance favored women at higher positions, 112 respondents (42.7%) agreed to apply positive action for men. The top indicators considered relevant to measure gender balance were: salary for similar positions (183/228, 80.3%), paid overtime (176/228, 77.2%), number of permanent positions (164/228, 71.9%), protected time for research (161/227, 70.9%), and training opportunities (157/227, 69.2%).Conclusions:Specific indicators may help to measure and promote gender balance and should be considered for implementation among healthcare professionals in neuro-oncology

Roux-en-Y gastric bypass surgery progressively alters radiologic measures of hypothalamic inflammation in obese patients

There is increased interest in whether bariatric surgeries such as Roux-en-Y gastric bypass (RYGB) achieve their profound weight-lowering effects in morbidly obese individuals through the brain. Hypothalamic inflammation is a well-recognized etiologic factor in obesity pathogenesis and so represents a potential target of RYGB, but clinical evidence in support of this is limited. We therefore assessed hypothalamic T2-weighted signal intensities (T2W SI) and fractional anisotropy (FA) values, 2 validated radiologic measures of brain inflammation, in relation to BMI and fat mass, as well as circulating inflammatory (C-reactive protein; CrP) and metabolic markers in a cohort of 27 RYGB patients at baseline and 6 and 12 months after surgery. We found that RYGB progressively increased hypothalamic T2W SI values, while it progressively decreased hypothalamic FA values. Regression analyses further revealed that this could be most strongly linked to plasma CrP levels, which independently predicted hypothalamic FA values when adjusting for age, sex, fat mass, and diabetes diagnosis. These findings suggest that RYGB has a major time-dependent impact on hypothalamic inflammation status, possibly by attenuating peripheral inflammation. They also suggest that hypothalamic FA values may provide a more specific radiologic measure of hypothalamic inflammation than more commonly used T2W SI values