FUS-mediated BBB opening leads to transient perfusion decrease and inflammation without acute or chronic brain lesion.

The permeabilization of the BBB to deliver therapeutics with MR-guided FUS redefines therapeutic strategies as it improves patient outcomes. To ensure the best translation towards clinical treatment, the evaluation of hemodynamic modifications in the CNS is necessary to refine treatment parameters. MR-guided FUS was applied at 1.

EEG-fMRI in awake rat and whole-brain simulations show decreased brain responsiveness to sensory stimulations during absence seizures.

In patients suffering absence epilepsy, recurring seizures can significantly decrease their quality of life and lead to yet untreatable comorbidities. Absence seizures are characterized by spike-and-wave discharges on the electroencephalogram associated with a transient alteration of consciousness. However, it is still unknown how the brain responds to external stimuli during and outside of seizures.

Microbeam Radiation Therapy Opens a Several Days' Vessel Permeability Window for Small Molecules in Brain Tumor Vessels.

Purpose: Synchrotron microbeam radiation therapy (MRT), based on an inhomogeneous geometric and microscopic irradiation pattern of the tissues with high-dose and high-dose-rate x-rays, enhances the permeability of brain tumor vessels. This study attempted to determine the time and size range of the permeability window induced by MRT in the blood-brain (tumor) barrier.

Methods And Materials: Rats-bearing 9L gliomas were exposed to MRT, either unidirectional (tumor dose, 406 Gy) or bidirectional (crossfired) (2 × 203 Gy).

Different Ecological Niches of Poisonous in Central and Marginal Distribution Ranges-Another Contribution to a Better Understanding of Balkan Endemic Nephropathy.

L. is a perennial herbaceous plant distributed throughout Europe, Asia Minor and Caucasus. It has been used as a medicinal plant since antiquity but not in recent times because it contains poisonous aristolochic acid, causing progressive kidney failure.

Tetraploids expanded beyond the mountain niche of their diploid ancestors in the mixed-ploidy grass Festuca amethystina L.

One promising area in understanding the responses of plants to ongoing global climate change is the adaptative effect of polyploidy. This work examines whether there is a coupling between the distribution of cytotypes and their biogeographical niche, and how different niches will affect their potential range. The study uses a range of techniques including flow cytometry, gradient and niche analysis, as well as distribution modelling.

Neurovascular multiparametric MRI defines epileptogenic and seizure propagation regions in experimental mesiotemporal lobe epilepsy.

Objective: Improving the identification of the epileptogenic zone and associated seizure-spreading regions represents a significant challenge. Innovative brain-imaging modalities tracking neurovascular dynamics during seizures may provide new disease biomarkers.

Methods: With use of a multi-parametric magnetic resonance imaging (MRI) analysis at 9.

In vivo characterization of physiological and metabolic changes related to isocitrate dehydrogenase 1 mutation expcression by multiparametric MRI and MRS in a rat model with orthotopically grafted human-derived glioblastoma cell lines.

The physiological mechanism induced by the isocitrate dehydrogenase 1 (IDH1) mutation, associated with better treatment response in gliomas, remains unknown. The aim of this preclinical study was to characterize the IDH1 mutation through in vivo multiparametric MRI and MRS. Multiparametric MRI, including the measurement of blood flow, vascularity, oxygenation, permeability, and in vivo MRS, was performed on a 4.

In vivo γ-aminobutyric acid increase as a biomarker of the epileptogenic zone: An unbiased metabolomics approach.

Objective: Following surgery, focal seizures relapse in 20% to 50% of cases due to the difficulty of delimiting the epileptogenic zone (EZ) by current imaging or electrophysiological techniques. Here, we evaluate an unbiased metabolomics approach based on ex vivo and in vivo nuclear magnetic resonance spectroscopy (MRS) methods to discriminate the EZ in a mouse model of mesiotemporal lobe epilepsy (MTLE).

Methods: Four weeks after unilateral injection of kainic acid (KA) into the dorsal hippocampus of mice (KA-MTLE model), we analyzed hippocampal and cortical samples with high-resolution magic angle spinning (HRMAS) magnetic resonance spectroscopy (MRS).

Hypertonic sodium lactate reverses brain oxygenation and metabolism dysfunction after traumatic brain injury.

Background: The mechanisms by which hypertonic sodium lactate (HSL) solution act in injured brain are unclear. We investigated the effects of HSL on brain metabolism, oxygenation, and perfusion in a rodent model of diffuse traumatic brain injury (TBI).

Methods: Thirty minutes after trauma, anaesthetised adult rats were randomly assigned to receive a 3 h infusion of either a saline solution (TBI-saline group) or HSL (TBI-HSL group).

Monochromatic minibeams radiotherapy: from healthy tissue-sparing effect studies toward first experimental glioma bearing rats therapy.

Purpose: The purpose of this study was to evaluate high-dose single fraction delivered with monochromatic X-rays minibeams for the radiotherapy of primary brain tumors in rats.

Methods And Materials: Two groups of healthy rats were irradiated with one anteroposterior minibeam incidence (four minibeams, 123 Gy prescribed dose at 1 cm depth in the brain) or two interleaved incidences (54 Gy prescribed dose in a 5 × 5 × 4.8 mm(3) volume centered in the right hemisphere), respectively.

Monochromatic minibeam radiotherapy: theoretical and experimental dosimetry for preclinical treatment plans.

Monochromatic x-ray minibeam radiotherapy is a new radiosurgery approach based on arrays of submillimetric interlaced planar x-ray beams. The aim of this study was to characterize the dose distributions obtained with this new modality when being used for preclinical trials. Monte Carlo simulations were performed in water phantoms.

Highly constrained backprojection for improving dynamic 3He MR ventilation imaging in rats.

The highly constrained backprojection algorithm (HYPR) has recently been shown to allow accelerated acquisition in various fields of MRI, including angiography, perfusion and diffusion imaging as well as hyperpolarized gas imaging. Increase in temporal resolution is of particular interest in the case of small animal ventilation imaging due to the high respiration rate. In the present study, the two-dimensional HYPR technique and its iterative version (I-HYPR) were applied to (3)He ventilation imaging in rats.

Spatially resolved assessment of serotonin-induced bronchoconstrictive responses in the rat lung using 3He ventilation MRI under spontaneous breathing conditions.

The effect on lung ventilation of bronchoconstriction induced by serotonin (intravenous injection of 50 microg/kg of serotonin) was imaged using a hyperpolarized (3)He MR ventilation protocol in spontaneously breathing rats. Lung function maps assessing airflow obstruction, a key feature in clinical pneumology, were derived from dynamic image series acquired after inhalation of (3)He gas. Dynamic ventilation (3)He MR images spanning a respiratory cycle were obtained using a retrospective cine image reconstruction procedure.

Longitudinal 3He and proton imaging of magnetite biodistribution in a rat model of instilled nanoparticles.

Epidemiological and toxicological studies have provided evidence that accidentally inhaled nanosize ultrafine particles can induce chronic or acute health damage. MRI, being noninvasive, is able to assess the biodistribution and clearance of magnetically labeled nanoparticles induced by instillation or inhalation. We report 3He and proton MRI follow-up of lung, liver, spleen, and kidney distribution of USPIO (ultrasmall superparamagnetic iron oxide) in a rat model.

Effects of ozone exposure in rat lungs investigated with hyperpolarized 3 He MRI.

Purpose: To investigate the effects of subchronic ozone exposure on rat lung ventilation using hyperpolarized (HP) (3)He MRI.

Materials And Methods: A total of 24 Sprague-Dawley rats, distributed in one control group and four groups exposed to 0.5 ppm ozone concentration for two days or six days, either continuously (22 hours/day) or alternatingly (12 hours/day).

Measurement of nonlinear pO2 decay in mouse lungs using 3He-MRI.

Spatial and temporal variations in oxygen partial pressure (pO(2)) during breath-hold can be exploited to obtain important regional parameters of lung function. In the course of apnea, the oxygen concentration is known to decay exponentially. Therefore, the initial pO(2) (p(0)) can be used to represent local ventilation, and the oxygen depletion time constant can characterize perfusion.

Alveolar oxygen partial pressure and oxygen depletion rate mapping in rats using 3He ventilation imaging.

A hyperpolarized 3He ventilation imaging protocol was implemented to assess alveolar pO2 values and the oxygen depletion rate in rats. The imaging protocol, which is based on spiral k-space sampling, was designed to acquire a high signal-to-noise ratio (SNR) T1-weighted ventilation series of images in a single breath-hold. Simulations were performed to estimate the accuracy and dependence of the pO2 imaging protocol on the image SNR and the RF flip-angle determination.

Retrospective cine 3He ventilation imaging under spontaneous breathing conditions: a non-invasive protocol for small-animal lung function imaging.

A non-invasive and free-breathing hyperpolarized (HP) (3)He imaging protocol for small animals was implemented and validated on rats for lung function imaging. Animals were allowed to breathe a mixture of air and (3)He from a mask and a gas reservoir fitted to their heads. Radial imaging sequences were used, and MRI signal intensity changes were monitored for retrospective cine image reconstruction.

Quantitative measurements of regional lung ventilation using helium-3 MRI in a methacholine-induced bronchoconstriction model.

Purpose: To demonstrate ventilation changes in an animal model of methacholine-induced bronchoconstriction using hyperpolarized (HP) helium-3 (He-3) MRI.

Materials And Methods: Bronchoconstriction was induced in 11 healthy rats using an intravenous injection of methacholine. The He-3 was laser-polarized using a custom-built system.

Dynamic 3He imaging for quantification of regional lung ventilation parameters.

Dynamic ventilation imaging using laser-polarized (3)He has a promising potential for elucidating the physiology and physiopathology of the lungs. In this study, a methodological approach is proposed for the assessment and quantification of local ventilation parameters. High-temporal-resolution coronal ventilation image series were obtained with a projection-reconstruction (PR) sequence combined with the sliding-window technique.

Helium3 polarization using spin exchange technique: application to simultaneous pulmonary ventilation/perfusion imaging in small animals.

Rationale And Objectives: To develop a simple and robust helium3 polarization system dedicated to small animal imaging. To demonstrate the potential of helium3 imaging for pulmonary ventilation and perfusion studies.

Methods: A home-built polarization system based on spin-exchange technique was used.