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1.
Food Sci Technol Int ; 28(2): 107-117, 2022 Mar.
Article in English | MEDLINE | ID: mdl-33563039

ABSTRACT

The microstructure, elemental distribution and rheological behavior of two varieties of gari and their doughs (eba) were investigated. SEM analysis revealed a concave structure with fibre-strands, which were altered after processing to eba. Gari nanostructures which were analyzed with TEM were not affected when processed to eba. SEM-EDX microanalysis revealed the presence of magnesium, potassium, calcium, manganese, iron, and cobalt for both varieties, which were altered after processing. Rheological analysis revealed increases in storage modulus, with concomitant loss factor for both varieties. Their viscosity decreased with increasing shear rate. GC-MS analysis revealed the presence of sugar, fatty acids, and steroids in both varieties, which were also affected after processing. Both varieties showed significant free radical scavenging activity which was not affected after processing. These results indicate that the conclave microstructure, elements and phytochemicals of both gari varieties are altered after processing to eba, with their nanostructure and antioxidant activity unaltered.


Subject(s)
Manihot , Dietary Fiber , Manihot/chemistry , Vegetables , Viscosity
2.
Med Phys ; 48(11): 6588-6596, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34532858

ABSTRACT

PURPOSE: During magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy for refractory tremor, high temperatures must be achieved and sustained for tissue necrosis. We assessed the impact of both patient-specific as well as procedure-related factors on the efficiency of acoustic energy transfer, or heating efficiency (HE). METHODS: Retrospective analysis of 92 consecutive patients (857 sonications) with essential tremor or tremor-dominant Parkinson's disease treated at a single institution. Temperature elevations at the target were measured for each sonication with MR thermometry. HE of each sonication was defined as the ratio of peak temperature elevation and the delivered energy. HE was analyzed with respect to patient skull features (area, thickness, skull density ratio [SDR]), computed from CT scans, as well as demographic and clinical variables (age, sex, diagnosis, and duration of symptoms). RESULTS: Across the full range of sonication energies that can be delivered with current devices (up to 36 kJ), average sonication HE was diminished in patients with lower SDR. In individual subjects, there was a progressive loss in HE as sonication energy was titrated up throughout the course of treatment, with a more rapid decline in patients with higher SDR. This energy-dependent loss in HE was not related to procedural factors, namely, the number of previous sonications, or the cumulative energy deposited during previous sonications. In contrast to SDR, neither skull area nor thickness was an independent predictor of average HE or the rate of its decline with increasing energies. In 11% of patients, all of whom with SDR < 0.45, sonication HE fell below the threshold to reach 54°C even with delivery of maximum energy. In contrast, temperatures ≥ 50°C could be obtained in all but one patient. CONCLUSIONS: SDR is predictive of sonication HE, and determines patient-specific limits on the magnitude of temperature elevation that can be achieved with current devices. These data inform strategies for predictable lesioning in MRgFUS thalamotomy.


Subject(s)
Heating , Sonication , Humans , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Retrospective Studies , Skull
4.
Elife ; 92020 12 04.
Article in English | MEDLINE | ID: mdl-33274715

ABSTRACT

Goal-directed behaviors are essential for normal function and significantly impaired in neuropsychiatric disorders. Despite extensive associations between genetic mutations and these disorders, the molecular contributions to goal-directed dysfunction remain unclear. We examined mice with constitutive and brain region-specific mutations in Neurexin1α, a neuropsychiatric disease-associated synaptic molecule, in value-based choice paradigms. We found Neurexin1α knockouts exhibited reduced selection of beneficial outcomes and impaired avoidance of costlier options. Reinforcement modeling suggested that this was driven by deficits in updating and representation of value. Disruption of Neurexin1α within telencephalic excitatory projection neurons, but not thalamic neurons, recapitulated choice abnormalities of global Neurexin1α knockouts. Furthermore, this selective forebrain excitatory knockout of Neurexin1α perturbed value-modulated neural signals within striatum, a central node in feedback-based reinforcement learning. By relating deficits in value-based decision-making to region-specific Nrxn1α disruption and changes in value-modulated neural activity, we reveal potential neural substrates for the pathophysiology of neuropsychiatric disease-associated cognitive dysfunction.


Subject(s)
Calcium-Binding Proteins/metabolism , Choice Behavior/physiology , Neural Cell Adhesion Molecules/metabolism , Neural Pathways/physiology , Neurons/physiology , Prosencephalon/physiology , Animals , Mice , Mice, Mutant Strains , Reward
6.
Metab Brain Dis ; 35(8): 1417-1428, 2020 12.
Article in English | MEDLINE | ID: mdl-32990928

ABSTRACT

Caseins are the most abundant milk proteins in mammalian species and are assembled in supra-macromolecular structures called micelles. In this study, the microstructural properties, particle size, and elemental composition of isolated casein from bovine milk and its therapeutic effect on oxidative and cholinergic activities linked to dementia in oxidative brain injury were investigated. SEM analysis of the isolated casein micelles from skimmed fresh bovine milk revealed spherical colloid aggregates, while TEM analysis revealed dispersed spherical particles with a mean size of 63.15 ± 4.77 nm. SEM-EDX analysis revealed clusters of carbon, oxygen, sulfur, copper, sodium, magnesium, potassium, iron, and selenium. Treatment of oxidative brain injury with the isolated casein micelles led to elevated levels of GSH, SOD, catalase, ENTPDase, 5'NTPase activities, while concomitantly suppressing MDA, cholesterol, HDL-c levels, acetylcholinesterase and lipase activities. Treatment with the isolated casein micelles led to complete depletion of oxidative generated lipid metabolites, while deactivating oxidative-activated lipid metabolic pathways. These results indicate the microstructural properties, particle size, elemental composition, and antioxidant neuroprotective effect of casein micelles from bovine milk. Thus, demonstrating the nutraceutical properties of milk in the management of oxidative induced cognitive impairment.


Subject(s)
Brain Injuries/metabolism , Caseins/administration & dosage , Micelles , Milk/metabolism , Neuroprotection/drug effects , Oxidative Stress/drug effects , Animals , Brain Injuries/drug therapy , Caseins/isolation & purification , Cattle , Dose-Response Relationship, Drug , Male , Milk/chemistry , Neuroprotection/physiology , Oxidative Stress/physiology , Particle Size , Rats
7.
Neuron ; 103(1): 92-101.e6, 2019 07 03.
Article in English | MEDLINE | ID: mdl-31097361

ABSTRACT

The dorsomedial striatum (DMS) is critically involved in motor control and reward processing, but the specific neural circuit mediators are poorly understood. Recent evidence highlights the extensive connectivity of low-threshold spiking interneurons (LTSIs) within local striatal circuitry; however, the in vivo function of LTSIs remains largely unexplored. We employed fiber photometry to assess LTSI calcium activity in a range of DMS-mediated behaviors, uncovering specific reward-related activity that is down-modulated during goal-directed learning. Using two mechanistically distinct manipulations, we demonstrated that this down-modulation of LTSI activity is critical for acquisition of novel contingencies, but not for their modification. In contrast, continued LTSI activation slowed instrumental learning. Similar manipulations of fast-spiking interneurons did not reproduce these effects, implying a specific function of LTSIs. Finally, we revealed a role for the γ-aminobutyric acid (GABA)ergic functions of LTSIs in learning. Together, our data provide new insights into this striatal interneuron subclass as important gatekeepers of goal-directed learning.


Subject(s)
Corpus Striatum/physiology , Goals , Interneurons/physiology , Learning/physiology , Animals , Appetite , Calcium Signaling/physiology , Conditioning, Operant/physiology , Electrophysiological Phenomena/physiology , Mice , Mice, Knockout , Potassium Channels, Inwardly Rectifying/genetics , Potassium Channels, Inwardly Rectifying/physiology , Reward , Vesicular Inhibitory Amino Acid Transport Proteins/genetics , Vesicular Inhibitory Amino Acid Transport Proteins/physiology , gamma-Aminobutyric Acid/physiology
8.
Front Neurosci ; 13: 50, 2019.
Article in English | MEDLINE | ID: mdl-30792620

ABSTRACT

Value-based decision making relies on distributed neural systems that weigh the benefits of actions against the cost required to obtain a given outcome. Perturbations of these systems are thought to underlie abnormalities in action selection seen across many neuropsychiatric disorders. Genetic tools in mice provide a promising opportunity to explore the cellular components of these systems and their molecular foundations. However, few tasks have been designed that robustly characterize how individual mice integrate differential reward benefits and cost in their selection of actions. Here we present a forced-choice, two-alternative task in which each option is associated with a specific reward outcome, and unique operant contingency. We employed global and individual trial measures to assess the choice patterns and behavioral flexibility of mice in response to differing "choice benefits" (modeled as varying reward magnitude ratios) and different modalities of "choice cost" (modeled as either increasing repetitive motor output to obtain reward or increased delay to reward delivery). We demonstrate that (1) mouse choice is highly sensitive to the relative benefit of outcomes; (2) choice costs are heavily discounted in environments with large discrepancies in relative reward; (3) divergent cost modalities are differentially integrated into action selection; (4) individual mouse sensitivity to reward benefit is correlated with sensitivity to reward costs. These paradigms reveal stable individual animal differences in value-based action selection, thereby providing a foundation for interrogating the neural circuit and molecular pathophysiology of goal-directed dysfunction.

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