Publications by authors named "Mohamed Tachrount"

Article Synopsis
  • The study investigates the mouse brain's premotor areas, challenging the idea that the secondary motor cortex (M2) is the sole higher-order motor area like in humans.
  • Researchers identified three distinct premotor areas in mice: anterior-lateral motor cortex (ALM), anterior-lateral M2 (aM2), and posterior-medial M2 (pM2), each with unique structural and functional features.
  • The findings suggest that ALM closely resembles the human anterior ventral premotor areas, while aM2 and pM2 share properties with human pre-SMA and cingulate cortex, providing insights into the similarities between the motor systems of humans and mice.
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Article Synopsis
  • - Psychedelic drugs, like 2,5-dimethoxy-4-iodoamphetamine ((±)-DOI), can potentially promote long-lasting improvements in brain plasticity and cognitive flexibility, which may help treat neuropsychiatric disorders.
  • - A study with young adult mice showed that a single dose of (±)-DOI increased brain volume in certain sensory areas and improved their ability to adapt to changes in a learning task one week later.
  • - The effects of (±)-DOI on cognitive flexibility depended on the timing of the drug's administration and the experiences that followed, suggesting that both timing and context are important for maximizing the therapeutic benefits of psychedelics in mental health treatment.
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Combining histology and ex vivo MRI from the same mouse brain is a powerful way to study brain microstructure. Mouse brains prepared for ex vivo MRI are often kept in storage solution for months, potentially becoming brittle and showing reduced antigenicity. Here, we describe a protocol for mouse brain dissection, tissue processing, paraffin embedding, sectioning, and staining.

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Introduction: Sciatica is a common condition and is associated with higher levels of pain, disability, poorer quality of life, and increased use of health resources compared with low back pain alone. Although many patients recover, a third develop persistent sciatica symptoms. It remains unclear, why some patients develop persistent sciatica as none of the traditionally considered clinical parameters (eg, symptom severity, routine MRI) are consistent prognostic factors.

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7,8-dihydroxyflavone (7,8-DHF) is a low molecular weight compound that can cross the blood brain barrier and has been implicated in numerous functions and behaviours. It is thought to have neuroprotective capability and has been shown to alleviate symptoms in a wide range of diseases. 7,8-DHF was administered systemically to wildtype mice during Morris water maze training.

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The surface of the human cerebellar cortex is much more tightly folded than the cerebral cortex. It was computationally reconstructed for the first time to the level of all individual folia from multicontrast high-resolution postmortem MRI scans. Its total shrinkage-corrected surface area (1,590 cm) was larger than expected or previously reported, equal to 78% of the total surface area of the human neocortex.

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Objective: Treatment of relapses in multiple sclerosis (MS) has not advanced beyond steroid use, which reduces acute loss of function, but has little effect on residual disability. Acute loss of function in an MS model (experimental autoimmune encephalomyelitis [EAE]) is partly due to central nervous system (CNS) hypoxia, and function can promptly improve upon breathing oxygen. Here, we investigate the cause of the hypoxia and whether it is due to a deficit in oxygen supply arising from impaired vascular perfusion.

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With the current practice of therapeutic hypothermia for neonatal encephalopathy, disability rates and the severity spectrum of cerebral palsy are reduced. Nevertheless, safe and effective adjunct therapies are needed to optimize outcomes. This study's objective was to assess if 18 mg/kg melatonin given rapidly over 2 h at 1 h after hypoxia-ischemia with cooling from 1-13 h was safe, achieved therapeutic levels within 3 h and augmented hypothermic neuroprotection.

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Purpose: The design and performance of a novel head coil setup for P spectroscopy at ultra-high field strengths (7T) is presented. The described system supports measurements at both the H and P resonance frequencies.

Methods: The novel coil consists of 2, actively detunable, coaxial birdcage coils to give homogeneous transmit, combined with a double resonant 30 channel receive array.

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Fluorinert (perfluorocarbon) represents an inexpensive option for minimizing susceptibility artifacts in ex vivo brain MRI scanning, and provides an alternative to Fomblin. However, its impact on fixed tissue and histological analysis has not been rigorously and quantitatively validated. In this study, we excised tissue blocks from 2 brain regions (frontal pole and cerebellum) of 5 formalin-fixed specimens (2 progressive supranuclear palsy cases, 3 controls).

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Therapeutic hypothermia is only partially protective for neonatal encephalopathy; there is an urgent need to develop treatments that augment cooling. Our objective was to assess safety, efficacy and pharmacokinetics of 5 and 15 mg/kg/24 h melatonin (proprietary formulation) administered at 2 h and 26 h after hypoxia-ischemia (HI) with cooling in a piglet model. Following moderate cerebral HI, 30 piglets were eligible and randomized to: i) Hypothermia (33.

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Purpose: To develop a new MRI technique to rapidly measure exchange rates in CEST MRI.

Methods: A novel pulse sequence for measuring chemical exchange rates through a progressive saturation recovery process, called PRO-QUEST (progressive saturation for quantifying exchange rates using saturation times), has been developed. Using this method, the water magnetization is sampled under non-steady-state conditions, and off-resonance saturation is interleaved with the acquisition of images obtained through a Look-Locker type of acquisition.

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Objective: Conventional magnetic resonance imaging (MRI) of the multiple sclerosis spinal cord is limited by low specificity regarding the underlying pathological processes, and new MRI metrics assessing microscopic damage are required. We aim to show for the first time that (i.e.

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Objective: This study reports on a novel brain pathology in young patients with frontal lobe epilepsy (FLE) that is distinct from focal cortical dysplasia (FCD).

Methods: Surgical specimens from 20 young adults with FLE (mean age, 30 years) were investigated with histological/immunohistochemical markers for cortical laminar architecture, mammalian target of (mTOR) pathway activation and inhibition, cellular autophagy, and synaptic vesicle-mediated trafficking as well as proteomics analysis. Findings were correlated with pre-/postoperative clinical, imaging, and electrophysiological data.

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Objective: Demyelination is a cardinal feature of multiple sclerosis, but it remains unclear why new lesions form, and whether they can be prevented. Neuropathological evidence suggests that demyelination can occur in the relative absence of lymphocytes, and with distinctive characteristics suggestive of a tissue energy deficit. The objective was to examine an experimental model of the early multiple sclerosis lesion and identify pathogenic mechanisms and opportunities for therapy.

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High-resolution magnetic resonance imaging (MRI) may improve the preoperative diagnosis of focal cortical dysplasia (FCD) in epilepsy. Quantitative 9.4T MRI was carried out (T1, T2, T2* and magnetization transfer ratio) on 13 cortical resections, representing pathologically confirmed FCD (five cases) and normal cortex.

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MR spectroscopy allows a noninvasive assessment of metabolic information in healthy and pathological central nervous system. Whereas MR spectroscopy has been extensively applied in the brain, only few spectroscopic studies of the spinal cord (SC) have been performed so far. For mice, due to additional technical challenges, in vivo 1H SC MRS has not yet been reported.

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With the increasing number of transgenic mouse models of human brain diseases, there is a need for a sensitive method that allows assessing quantitative whole brain perfusion within a reasonable scan time. Arterial spin labeling (ASL), an MRI technique that permits the noninvasive quantification of cerebral blood flow, has been used to assess rodents brain perfusion. For mice, the reported experiments performed with continuous or pulsed ASL were challenged by poor multislice capability, limited sensitivity, or quantification issues.

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Vessel size index (VSI), a parameter related to the distribution of vessel diameters, may be estimated using two MRI approaches: (i) dynamic susceptibility contrast (DSC) MRI following the injection of a bolus of Gd-chelate. This technique is routinely applied in the clinic to assess intracranial tissue perfusion in patients; (ii) steady-state susceptibility contrast with USPIO contrast agents, which is considered here as the standard method. Such agents are not available for human yet and the steady-state approach is currently limited to animal studies.

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