Publications by authors named "Nachiket Nadkarni"

Article Synopsis
  • * A new imaging technique called gluCEST allows researchers to detect changes in glutamate distribution throughout the entire brain with better sensitivity and resolution compared to older methods, primarily in high-field settings.
  • * In a pioneering study, researchers explored gluCEST contrast in mouse lemur primates, finding significant age-related changes in various brain regions, paving the way for potential applications in understanding brain aging and related diseases.
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Measures of resting-state functional connectivity allow the description of neuronal networks in humans and provide a window on brain function in normal and pathological conditions. Characterizing neuronal networks in animals is complementary to studies in humans to understand how evolution has modelled network architecture. The mouse lemur (Microcebus murinus) is one of the smallest and more phylogenetically distant primates as compared to humans.

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Background: Masitinib is a selective tyrosine kinase inhibitor that modulates mast cells activity. A previous phase II study reported a cognitive effect of masitinib in patients with Alzheimer's disease.

Objective: We aimed to shed light on the mode of action of masitinib in Alzheimer's disease.

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Small-mammal neuroimaging offers incredible opportunities to investigate structural and functional aspects of the brain. Many tools have been developed in the last decade to analyse small animal data, but current softwares are less mature than the available tools that process human brain data. The Python package Sammba-MRI (SmAll-MaMmal BrAin MRI in Python; http://sammba-mri.

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Preclinical applications of resting-state functional magnetic resonance imaging (rsfMRI) offer the possibility to non-invasively probe whole-brain network dynamics and to investigate the determinants of altered network signatures observed in human studies. Mouse rsfMRI has been increasingly adopted by numerous laboratories worldwide. Here we describe a multi-centre comparison of 17 mouse rsfMRI datasets via a common image processing and analysis pipeline.

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We present a dataset made of 3D digital brain templates and of an atlas of the gray mouse lemur (), a small prosimian primate of growing interest for studies of primate biology and evolution. A template image was constructed from magnetic resonance imaging (MRI) data of 34 animals. This template was then manually segmented into 40 cortical, 74 subcortical and 6 cerebro-spinal fluid (CSF) regions.

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The gray mouse lemur (Microcebus murinus) is a small prosimian of growing interest for studies of primate biology and evolution, and notably as a model organism of brain aging. As brain atlases are essential tools for brain investigation, the objective of the current work was to create the first 3D digital atlas of the mouse lemur brain. For this, a template image was constructed from in vivo magnetic resonance imaging (MRI) data of 34 animals.

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External information can modify the subjective value of a tasted stimulus, but little is known about neural mechanisms underlying these behavioral modifications. This study used flavored drinks to produce variable degrees of discrepancy between expected and received flavor. During a learning session, 43 healthy young men learned 4 symbol-flavor associations.

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Article Synopsis
  • - The study explored how a high-fat diet impacts energy consumption and obesity in rats, distinguishing between those prone to obesity (fat sensitive, FS) and those less likely to gain weight (fat resistant, FR).
  • - After an initial high-fat diet, rats were given separate access to protein while eating a carb-fat mixture, leading to increased protein intake and reduced fat and carb intake, which prevented weight gain in both FS and FR rats.
  • - Results showed that FS rats maintained lower food intake and fat accumulation, despite having genes that promote fat production active, indicating macronutrient choices play a critical role in managing weight gain.
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We previously reported that rats prone to obesity exhibit an exaggerated increase in glucose oxidation and an exaggerated decline in lipid oxidation under a low-fat high-carbohydrate (LF/HC) diet. The aim of the present study was to investigate the mechanisms involved in these metabolic dysregulations. After a 1-week adaptation to laboratory conditions, 48 male Wistar rats were fed a LF/HC diet for 3 weeks.

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Consumption of a product is preceded by an anticipation of its qualities by the consumer, which can itself modify the consumption experience. Improved knowledge of anticipation would allow better manipulation of it, for example to enhance the acceptance of healthier foods. According to the Assimilation-Contrast theory, the size of anticipation-reality divergence determines how anticipation influences consumers' satisfaction.

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Intake of sodas has been shown to increase energy intake and to contribute to obesity in humans and in animal models, although the magnitude and importance of these effects are still debated. Moreover, intake of sugar sweetened beverages is often associated with high-fat food consumption in humans. We studied two different accesses to a sucrose-sweetened water (SSW, 12.

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Obesity-prone (OP) rodents are used as models of human obesity predisposition. The goal of the present study was to identify preexisting defects in energy expenditure components in OP rats. Two studies were performed.

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Background: Sensitivity to obesity is highly variable in humans, and rats fed a high fat diet (HFD) are used as a model of this inhomogeneity. Energy expenditure components (basal metabolism, thermic effect of feeding, activity) and variations in substrate partitioning are possible factors underlying the variability. Unfortunately, in rats as in humans, results have often been inconclusive and measurements usually made after obesity onset, obscuring if metabolism was a cause or consequence.

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This study focused on the fate of the satiating potency of dietary fibers when solubilized in a fat-containing medium. Fourteen percent of either guar gum (GG) or fructo-oligosaccharide (FOS) or a mixture of the 2 (GG-FOS, 5% GG and 9% FOS) were solubilized in water or an oil emulsion (18-21% rapeseed oil in water, v:v) and administered by gavage to mice before their food intake was monitored. When compared with water (control), only GG-FOS solubilized in water or in the oil emulsion reduced daily energy intake by 21.

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In this article, we review some fundamentals of indirect calorimetry in mice and rats, and open the discussion on several debated aspects of the configuration and tuning of indirect calorimeters. On the particularly contested issue of adjustment of energy expenditure values for body size and body composition, we discuss several of the most used methods and their results when tested on a previously published set of data. We conclude that neither body weight (BW), exponents of BW, nor lean body mass (LBM) are sufficient.

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The present review summarises current knowledge and recent findings on the modulation of appetite by dietary protein, via both peripheral and central mechanisms. Of the three macronutrients, proteins are recognised as the strongest inhibitor of food intake. The well-recognised poor palatability of proteins is not the principal mechanism explaining the decrease in high-protein (HP) diet intake.

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Chronic stress is associated with negative health outcomes and is linked with neuroendocrine changes, deleterious effects on innate and adaptive immunity, and central nervous system neuropathology. Although stress management is commonly advocated clinically, there is insufficient mechanistic understanding of how decreasing stress affects disease pathogenesis. Therefore, we have developed a "calm mouse model" with caging enhancements designed to reduce murine stress.

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Obesity has become a major global health problem. Recently, attention has focused on the benefits of fermentable carbohydrates on modulating metabolism. Here, we take a system approach to investigate the physiological effects of supplementation with oligofructose-enriched inulin (In).

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Individuals exhibit a great variation in their body weight (BW) gain response to a high fat diet. Identification of predictive factors would enable better directed intervention toward susceptible individuals to treat obesity, and uncover potential mechanisms for treatment targeting. We set out to identify predictive behavioral and metabolic factors in an outbred rat model.

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Nuclear spatial positioning plays an important role in the epigenetic regulation of eukaryotic gene expression. Here we show a role for nuclear spatial positioning in regulating episomal transgenes that are delivered by virus-like particles (VLPs). VLPs mediate the delivery of plasmid DNA (pDNA) to cell nuclei but lack viral factors involved in initiating and regulating transcription.

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Article Synopsis
  • The study investigates the variable number tandem repeat (VNTR) polymorphism in the PER3 gene, which is involved in human circadian rhythms, specifically its association with sleep patterns and diurnal preferences.
  • Researchers measured the global frequencies of the 4-repeat and 5-repeat alleles in various indigenous populations, finding significant variability across ethnic groups, with the 4-repeat allele being most common in Mongolia and least common in Papua New Guinea.
  • The analysis concluded that there is no evidence of natural selection affecting allele frequencies in PER3, as observed patterns did not correlate with factors like latitude or mean annual sunlight, and allele differences between major population groups were similar to those seen in neutral genetic variations.
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