scholarly journals Genetic Approaches Using Zebrafish to Study the Microbiota–Gut–Brain Axis in Neurological Disorders

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 566
Author(s):  
Jae-Geun Lee ◽  
Hyun-Ju Cho ◽  
Yun-Mi Jeong ◽  
Jeong-Soo Lee
Keyword(s):  
Neurological Disorders ◽  
Genetic Model ◽  
Molecular Genetic ◽  
Autism Spectrum ◽  
Behavioral Abnormalities ◽  
Bidirectional Signaling ◽  
Intestinal Dysbiosis ◽  
The Central Nervous System ◽  
The Brain

The microbiota–gut–brain axis (MGBA) is a bidirectional signaling pathway mediating the interaction of the microbiota, the intestine, and the central nervous system. While the MGBA plays a pivotal role in normal development and physiology of the nervous and gastrointestinal system of the host, its dysfunction has been strongly implicated in neurological disorders, where intestinal dysbiosis and derived metabolites cause barrier permeability defects and elicit local inflammation of the gastrointestinal tract, concomitant with increased pro-inflammatory cytokines, mobilization and infiltration of immune cells into the brain, and the dysregulated activation of the vagus nerve, culminating in neuroinflammation and neuronal dysfunction of the brain and behavioral abnormalities. In this topical review, we summarize recent findings in human and animal models regarding the roles of the MGBA in physiological and neuropathological conditions, and discuss the molecular, genetic, and neurobehavioral characteristics of zebrafish as an animal model to study the MGBA. The exploitation of zebrafish as an amenable genetic model combined with in vivo imaging capabilities and gnotobiotic approaches at the whole organism level may reveal novel mechanistic insights into microbiota–gut–brain interactions, especially in the context of neurological disorders such as autism spectrum disorder and Alzheimer’s disease.

scholarly journals Induction of core symptoms of autism spectrum disorders by in vivo CRISPR/Cas9-based gene editing in the brain of adolescent rhesus monkeys

2020 ◽  
Author(s):  
Shi-Hao Wu ◽  
Xiao Li ◽  
Dong-Dong Qin ◽  
Lin-Heng Zhang ◽  
Tian-Lin Cheng ◽  
...  
Keyword(s):  
Autism Spectrum Disorders ◽  
Rhesus Monkeys ◽  
Gene Editing ◽  
Autism Spectrum ◽  
Genetically Engineered ◽  
Behavioral Abnormalities ◽  
Spectrum Disorders ◽  
Rapid Generation ◽  
The Brain

AbstractAlthough CRISPR/Cas9-mediated gene editing is widely applied to mimic human disorders, whether acute manipulation of disease-causing genes in the brain leads to behavioral abnormalities in non-human primates remains to be determined. Here we induced genetic mutations in MECP2, a critical gene linked to Rett syndrome (RTT) and autism spectrum disorders (ASDs), in the hippocampus (DG and CA1–4) of adolescent rhesus monkeys (Macaca mulatta) in vivo via adeno-associated virus (AAV)-delivered Staphylococcus aureus Cas9 with sgRNAs targeting MECP2. In comparison to monkeys injected with AAV-SaCas9 alone (n = 4), numerous autistic-like behavioral abnormalities were identified in the AAV-SaCas9-sgMECP2-injected monkeys (n = 7), including social interaction deficits, abnormal sleep patterns, insensitivity to aversive stimuli, abnormal hand motions and defective social reward behaviors. Furthermore, some aspects of ASDs and RTT, such as stereotypic behaviors, did not appear in the MECP2 gene-edited monkeys, suggesting that different brain areas likely contribute to distinct ASD symptoms. This study showed that acute manipulation of disease-causing genes via in vivo gene editing directly led to behavioral changes in adolescent primates, paving the way for the rapid generation of genetically engineered non-human primate models for neurobiological studies and therapeutic development.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

Intake of Anti-Epileptic Drugs and their Influences on Sexual Dysfunctions

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Roheela Yasmeen ◽  
Nida Mobeen ◽  
Muhammad Amjad Khan ◽  
Irfan Aslam ◽  
Samia Chaudhry
Keyword(s):  
Quality Of Life ◽  
Sexual Dysfunction ◽  
Neurological Disorders ◽  
Penile Erection ◽  
The Central Nervous System ◽  
Relationship Of ◽  
The Relationship ◽  
The Brain ◽  
Psychiatric Problems

Epilepsy which is also called seizures disorder is an uncontrolled action of the central nervous system. Itis not a single disease but a set of neurological disorders. Actually in this situation, the brain does notreceive a precise signal and as a result an abnormal condition is produced that is usually involuntary inaction. In this review, we aimed to focus on the relationship of anti-epileptic drugs with sexual dysfunctionand adaptation of better remedies that improve a patient’s family life. Sexual dysfunction is a commoncomorbidity in people with epilepsy which badly affects their quality of life. Sexual dysfunction is causedby different factors like psychiatric problems, anti-epileptic drugs (AEDs) and social factors etc. Sexualdysfunctions include ejaculatory failure, lessen libido, penile erection in men and irregular menstrual cyclein women. Common drugs such as Topiramate, Gabapentin (GBP), Valproate (VA), Carbamazepine (CBZ),Olanzapine (OL) and Risperidone (RTG) that are in practice to treat epilepsy usually produced adverseeffect on sexual dysfunction. Even though a lot of studies have been carried out to control sexualdysfunction in epilepsy’s patient, but still research is going on. Medicine such as Cyproheptadine,Mianserin, Buspirone, Yohimbine were found better to treat epilepsy with minimum side effects of sexualdysfunction. Moreover, it is also seen that certain vasodilators, folate , and vitamin supplements areeffective in improving the quality of life.

Effects of CSF Properties on Brain Response Under Impact Loading

2009 ◽  
Author(s):  
M. S. Chafi ◽  
V. Dirisala ◽  
G. Karami ◽  
M. Ziejewski
Keyword(s):  
Human Head ◽  
Brain Response ◽  
Pia Mater ◽  
Mechanical Shocks ◽  
The Central Nervous System ◽  
Simultaneous Loading ◽  
The Impact ◽  
Impact Experiments ◽  
The Brain

In the central nervous system, the subarachnoid space is the interval between the arachnoid membrane and the pia mater. It is filled with a clear, watery liquid called cerebrospinal fluid (CSF). The CSF buffers the brain against mechanical shocks and creates buoyancy to protect it from the forces of gravity. The relative motion of the brain due to a simultaneous loading is caused because the skull and brain have different densities and the CSF surrounds the brain. The impact experiments are usually carried out on cadavers with no CSF included because of the autolysis. Even in the cadaveric head impact experiments by Hardy et al. [1], where the specimens are repressurized using artificial CSF, this is not known how far this can replicate the real functionality of CSF. With such motivation, a special interest lies on how to model this feature in a finite element (FE) modeling of the human head because it is questionable if one uses in vivo CSF properties (i.e. bulk modulus of 2.19 GPa) to validate a FE human head against cadaveric experimental data.

scholarly journals Vascular Dysfunction Induced by Mercury Exposure

2019 ◽  
Vol 20 (10) ◽  
pp. 2435 ◽  
Author(s):  
Tetsuya Takahashi ◽  
Takayoshi Shimohata
Keyword(s):  
Oxidative Stress ◽  
Vascular Dysfunction ◽  
Brain Parenchyma ◽  
Transport Systems ◽  
Mehg Exposure ◽  
In Vivo Models ◽  
The Central Nervous System ◽  
The Brain

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.

Quantitative neurogenetics: applications in understanding disease

2021 ◽  
Author(s):  
Ali Afrasiabi ◽  
Jeremy T. Keane ◽  
Julian Ik-Tsen Heng ◽  
Elizabeth E. Palmer ◽  
Nigel H. Lovell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Genetic Risk ◽  
Tissue Specificity ◽  
High Throughput Sequencing ◽  
Molecular Genetic ◽  
Brain Dysfunction ◽  
Neural Cells ◽  
Expression Index ◽  
The Central Nervous System ◽  
The Brain

Neurodevelopmental and neurodegenerative disorders (NNDs) are a group of conditions with a broad range of core and co-morbidities, associated with dysfunction of the central nervous system. Improvements in high throughput sequencing have led to the detection of putative risk genetic loci for NNDs, however, quantitative neurogenetic approaches need to be further developed in order to establish causality and underlying molecular genetic mechanisms of pathogenesis. Here, we discuss an approach for prioritizing the contribution of genetic risk loci to complex-NND pathogenesis by estimating the possible impacts of these loci on gene regulation. Furthermore, we highlight the use of a tissue-specificity gene expression index and the application of artificial intelligence (AI) to improve the interpretation of the role of genetic risk elements in NND pathogenesis. Given that NND symptoms are associated with brain dysfunction, risk loci with direct, causative actions would comprise genes with essential functions in neural cells that are highly expressed in the brain. Indeed, NND risk genes implicated in brain dysfunction are disproportionately enriched in the brain compared with other tissues, which we refer to as brain-specific expressed genes. In addition, the tissue-specificity gene expression index can be used as a handle to identify non-brain contexts that are involved in NND pathogenesis. Lastly, we discuss how using an AI approach provides the opportunity to integrate the biological impacts of risk loci to identify those putative combinations of causative relationships through which genetic factors contribute to NND pathogenesis.

scholarly journals PET Imaging of [11C]MPC-6827, a Microtubule-Based Radiotracer in Non-Human Primate Brains

Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2289
Author(s):  
Naresh Damuka ◽  
Paul Czoty ◽  
Ashley Davis ◽  
Michael Nader ◽  
Susan Nader ◽  
...  
Keyword(s):  
Pet Imaging ◽  
Neurological Disorders ◽  
Healthy Male ◽  
Time Activity ◽  
Positron Emission ◽  
Pet Ct ◽  
Scan Data ◽  
The Brain ◽  
Human Primate

Dysregulation of microtubules is commonly associated with several psychiatric and neurological disorders, including addiction and Alzheimer’s disease. Imaging of microtubules in vivo using positron emission tomography (PET) could provide valuable information on their role in the development of disease pathogenesis and aid in improving therapeutic regimens. We developed [11C]MPC-6827, the first brain-penetrating PET radiotracer to image microtubules in vivo in the mouse brain. The aim of the present study was to assess the reproducibility of [11C]MPC-6827 PET imaging in non-human primate brains. Two dynamic 0–120 min PET/CT imaging scans were performed in each of four healthy male cynomolgus monkeys approximately one week apart. Time activity curves (TACs) and standard uptake values (SUVs) were determined for whole brains and specific regions of the brains and compared between the “test” and “retest” data. [11C]MPC-6827 showed excellent brain uptake with good pharmacokinetics in non-human primate brains, with significant correlation between the test and retest scan data (r = 0.77, p = 0.023). These initial evaluations demonstrate the high translational potential of [11C]MPC-6827 to image microtubules in the brain in vivo in monkey models of neurological and psychiatric diseases.

scholarly journals Locus Coeruleus Magnetic Resonance Imaging in Neurological Diseases

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Alessandro Galgani ◽  
Francesco Lombardo ◽  
Daniele Della Latta ◽  
Nicola Martini ◽  
Ubaldo Bonuccelli ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Neurological Disorders ◽  
Potential Role ◽  
Neurological Diseases ◽  
Mri Findings ◽  
Promising Tool ◽  
Experimental Tool ◽  
Early Biomarker ◽  
The Brain

Abstract Purpose of Review Locus coeruleus (LC) is the main noradrenergic nucleus of the brain, and its degeneration is considered to be key in the pathogenesis of neurodegenerative diseases. In the last 15 years,MRI has been used to assess LC in vivo, both in healthy subjects and in patients suffering from neurological disorders. In this review, we summarize the main findings of LC-MRI studies, interpreting them in light of preclinical and histopathological data, and discussing its potential role as diagnostic and experimental tool. Recent findings LC-MRI findings were largely in agreement with neuropathological evidences; LC signal showed to be not significantly affected during normal aging and to correlate with cognitive performances. On the contrary, a marked reduction of LC signal was observed in patients suffering from neurodegenerative disorders, with specific features. Summary LC-MRI is a promising tool, which may be used in the future to explore LC pathophysiology as well as an early biomarker for degenerative diseases.

scholarly journals Intranasal Delivery of Nanoformulations: A Potential Way of Treatment for Neurological Disorders

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1929 ◽  
Author(s):  
Salman Ul Islam ◽  
Adeeb Shehzad ◽  
Muhammad Bilal Ahmed ◽  
Young Sup Lee
Keyword(s):  
Drug Delivery ◽  
Neurological Disorders ◽  
Neurological Diseases ◽  
Nasal Delivery ◽  
Intranasal Route ◽  
Drug Molecules ◽  
Surface Enhanced ◽  
Effective Delivery ◽  
The Central Nervous System ◽  
The Brain

Although the global prevalence of neurological disorders such as Parkinson’s disease, Alzheimer’s disease, glioblastoma, epilepsy, and multiple sclerosis is steadily increasing, effective delivery of drug molecules in therapeutic quantities to the central nervous system (CNS) is still lacking. The blood brain barrier (BBB) is the major obstacle for the entry of drugs into the brain, as it comprises a tight layer of endothelial cells surrounded by astrocyte foot processes that limit drugs’ entry. In recent times, intranasal drug delivery has emerged as a reliable method to bypass the BBB and treat neurological diseases. The intranasal route for drug delivery to the brain with both solution and particulate formulations has been demonstrated repeatedly in preclinical models, including in human trials. The key features determining the efficacy of drug delivery via the intranasal route include delivery to the olfactory area of the nares, a longer retention time at the nasal mucosal surface, enhanced penetration of the drugs through the nasal epithelia, and reduced drug metabolism in the nasal cavity. This review describes important neurological disorders, challenges in drug delivery to the disordered CNS, and new nasal delivery techniques designed to overcome these challenges and facilitate more efficient and targeted drug delivery. The potential for treatment possibilities with intranasal transfer of drugs will increase with the development of more effective formulations and delivery devices.

scholarly journals In vivo delivery of a fluorescent FPR2/ALX-targeted probe using focused ultrasound and microbubbles to image activated microglia

2020 ◽  
Vol 1 (5) ◽  
pp. 385-389
Author(s):  
Sophie V. Morse ◽  
Tamara Boltersdorf ◽  
Tiffany G. Chan ◽  
Felicity N. E. Gavins ◽  
James J. Choi ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Focused Ultrasound ◽  
Imaging Agent ◽  
Targeted Imaging ◽  
Activated Microglia ◽  
The Brain ◽  
In Vivo Delivery

Targeted imaging agent labels activated microglia when delivered into the brain with focused ultrasound and microbubbles – a tool to investigate inflammation in neurological disorders.

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