scholarly journals MRI- and histologically derived neuroanatomical atlas of the Ambystoma mexicanum (axolotl)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ivan Lazcano ◽  
Abraham Cisneros-Mejorado ◽  
Luis Concha ◽  
Juan José Ortiz-Retana ◽  
Eduardo A. Garza-Villarreal ◽  
...  
Keyword(s):  
Ambystoma Mexicanum ◽  
Brain Atlas ◽  
Future Research ◽  
Brain Anatomy ◽  
Vertebrate Model ◽  
Magnetic Resonance Imaging Mri ◽  
Brain And Spinal Cord ◽  
The Brain ◽  
Recent Sequencing

AbstractAmphibians are an important vertebrate model system to understand anatomy, genetics and physiology. Importantly, the brain and spinal cord of adult urodels (salamanders) have an incredible regeneration capacity, contrary to anurans (frogs) and the rest of adult vertebrates. Among these amphibians, the axolotl (Ambystoma mexicanum) has gained most attention because of the surge in the understanding of central nervous system (CNS) regeneration and the recent sequencing of its whole genome. However, a complete comprehension of the brain anatomy is not available. In the present study we created a magnetic resonance imaging (MRI) atlas of the in vivo neuroanatomy of the juvenile axolotl brain. This is the first MRI atlas for this species and includes three levels: (1) 82 regions of interest (ROIs) and a version with 64 ROIs; (2) a division of the brain according to the embryological origin of the neural tube, and (3) left and right hemispheres. Additionally, we localized the myelin rich regions of the juvenile brain. The atlas, the template that the atlas was derived from, and a masking file, can be found on Zenodo at 10.5281/zenodo.4595016. This MRI brain atlas aims to be an important tool for future research of the axolotl brain and that of other amphibians.

scholarly journals MRI- and histologically derived neuroanatomical atlas of the Ambystoma mexicanum (axolotl)

2020 ◽  
Author(s):  
Iván Lazcano ◽  
Abraham Cisneros-Mejorado ◽  
Luis Concha ◽  
Juan José Ortíz Retana ◽  
Eduardo A. Garza-Villarreal ◽  
...  
Keyword(s):  
Ambystoma Mexicanum ◽  
Brain Atlas ◽  
Future Research ◽  
Brain Anatomy ◽  
Vertebrate Model ◽  
Left And Right ◽  
Brain And Spinal Cord ◽  
The Brain ◽  
Recent Sequencing

AbstractAmphibians are an important vertebrate model system to understand anatomy, genetics and physiology. Importantly, the brain and spinal cord of adult urodels (salamanders) have an incredible regeneration capacity, contrary to anurans (frogs) and the rest of adult vertebrates. Among these amphibians, the axolotl (Ambystoma mexicanum) has gained most attention because of the surge in the understanding of CNS regeneration and the recent sequencing of its whole genome. However, a complete comprehension of the brain anatomy is not available. In the present study we created a magnetic resonance imaging atlas of the in vivo neuroanatomy of the juvenile axolotl brain. This is the first MRI atlas for this species and includes 3 levels: 1) 80 regions of interest (ROIs); 2) a division of the brain according to the embryological origin of the neural tube, and 3) left and right hemispheres. Additionally, we localized the myelin rich regions of the juvenile brain. The atlas, the template that the atlas was derived from, and a masking file, can be found on Zenodo at DOI: 10.5281/zenodo.4311937. This MRI brain atlas aims to be an important tool for future research of the axolotl brain and that of other amphibians.

Imaging

2017 ◽  
Author(s):  
Robert Laureno
Keyword(s):  
Resonance Imaging ◽  
Cross Sectional ◽  
Advantages And Disadvantages ◽  
Mri Scans ◽  
Cross Sectional Imaging ◽  
Magnetic Resonance Imaging Mri ◽  
Cellular Pathology ◽  
Brain And Spinal Cord ◽  
The Brain

This chapter on “Imaging” examines the relative advantages and disadvantages of computed tomography (CT) and magnetic resonance imaging (MRI) scans. It compares the modalities to each other and to gross neuropathology. For several decades, neurologists have been able to view cross-sectional images of living patients. Analogous to gross neuropathology, cross-sectional imaging displays the brain as an entire organ but does not demonstrate microscopic tissue or cellular pathology. By allowing practitioners to view sections of brain and spinal cord in vivo, imaging has improved neurologic practice and facilitated clinical research. This chapter deals with imaging topics that are important to the neurologist. The timing of scans, the effects of gravity, and the importance of plane of section are considered. Imaging is compared to gross neuropathology, and MRI is compared to CT.

scholarly journals Recapitulate development to promote axonal regeneration: good or bad approach?

2006 ◽  
Vol 361 (1473) ◽  
pp. 1565-1574 ◽  
Author(s):  
Marie T Filbin
Keyword(s):  
Spinal Cord ◽  
Axonal Regeneration ◽  
Molecular Level ◽  
Signal Transduction Pathway ◽  
Developmental Changes ◽  
Transduction Pathway ◽  
The Past ◽  
Brain And Spinal Cord ◽  
The Brain

In the past decade there has been an explosion in our understanding, at the molecular level, of why axons in the adult, mammalian central nervous system (CNS) do not spontaneously regenerate while their younger counterparts do. Now a number of inhibitors of axonal regeneration have been described, some of the receptors they interact with to transduce the inhibitory signal are known, as are some of the steps in the signal transduction pathway that is responsible for inhibition. In addition, developmental changes in the environment and in the neurons themselves are also now better understood. This knowledge in turn reveals novel, putative sites for drug development and therapeutic intervention after injury to the brain and spinal cord. The challenge now is to determine which of these putative treatments are the most effective and if they would be better applied in combination rather than alone. In this review I will summarize what we have learnt about these molecules and how they signal. Importantly, I will also describe approches that have been shown to block inhibitors and encourage regeneration in vivo . I will also speculate on what the differences are between the neonatal and adult CNS that allow the former to regenerate and the latter not to.

scholarly journals Adenosine A2AReceptors in Substance Use Disorders: A Focus on Cocaine

Cells ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 1372 ◽  
Author(s):  
Karolina Wydra ◽  
Dawid Gawliński ◽  
Kinga Gawlińska ◽  
Małgorzata Frankowska ◽  
Dasiel O. Borroto-Escuela ◽  
...  
Keyword(s):  
Substance Use ◽  
Substance Use Disorders ◽  
Current Knowledge ◽  
Ex Vivo ◽  
D2 Receptors ◽  
Future Research ◽  
Receptor Complexes ◽  
Abused Drugs ◽  
The Brain

Several psychoactive drugs can evoke substance use disorders (SUD) in humans and animals, and these include psychostimulants, opioids, cannabinoids (CB), nicotine, and alcohol. The etiology, mechanistic processes, and the therapeutic options to deal with SUD are not well understood. The common feature of all abused drugs is that they increase dopamine (DA) neurotransmission within the mesocorticolimbic circuitry of the brain followed by the activation of DA receptors. D2 receptors were proposed as important molecular targets for SUD. The findings showed that D2 receptors formed heteromeric complexes with other GPCRs, which forced the addiction research area in new directions. In this review, we updated the view on the brain D2 receptor complexes with adenosine (A)2A receptors (A2AR) and discussed the role of A2AR in different aspects of addiction phenotypes in laboratory animal procedures that permit the highly complex syndrome of human drug addiction. We presented the current knowledge on the neurochemical in vivo and ex vivo mechanisms related to cocaine use disorder (CUD) and discussed future research directions for A2AR heteromeric complexes in SUD.

scholarly journals Magnetic Nanoparticles as In Vivo Tracers for Alzheimer’s Disease

2020 ◽  
Vol 6 (1) ◽  
pp. 13
Author(s):  
Bhargy Sharma ◽  
Konstantin Pervushin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Diagnosis ◽  
Contrast Agents ◽  
Neurological Diseases ◽  
Pulse Sequences ◽  
Experimental Conditions ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Drug formulations and suitable methods for their detection play a very crucial role in the development of therapeutics towards degenerative neurological diseases. For diseases such as Alzheimer’s disease, magnetic resonance imaging (MRI) is a non-invasive clinical technique suitable for early diagnosis. In this review, we will discuss the different experimental conditions which can push MRI as the technique of choice and the gold standard for early diagnosis of Alzheimer’s disease. Here, we describe and compare various techniques for administration of nanoparticles targeted to the brain and suitable formulations of nanoparticles for use as magnetically active therapeutic probes in drug delivery targeting the brain. We explore different physiological pathways involved in the transport of such nanoparticles for successful entry in the brain. In our lab, we have used different formulations of iron oxide nanoparticles (IONPs) and protein nanocages as contrast agents in anatomical MRI of an Alzheimer’s disease (AD) brain. We compare these coatings and their benefits to provide the best contrast in addition to biocompatibility properties to be used as sustainable drug-release systems. In the later sections, the contrast enhancement techniques in MRI studies are discussed. Examples of contrast-enhanced imaging using advanced pulse sequences are discussed with the main focus on important studies in the field of neurological diseases. In addition, T1 contrast agents such as gadolinium chelates are compared with the T2 contrast agents mainly made of superparamagnetic inorganic metal nanoparticles.

scholarly journals Automatic substantia nigra segmentation in neuromelanin-sensitive MRI by deep neural network in patients with prodromal and manifest synucleinopathy

2019 ◽  
pp. S453-S458
Author(s):  
R. Krupička ◽  
S. Mareček ◽  
C. Malá ◽  
M. Lang ◽  
O. Klempíř ◽  
...  
Keyword(s):  
Neural Network ◽  
Substantia Nigra ◽  
Signal Intensity ◽  
Substantia Nigra Pars Compacta ◽  
The Neural Network ◽  
Intensity Information ◽  
Ideal Tool ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Neuromelanin (NM) is a black pigment located in the brain in substantia nigra pars compacta (SN) and locus coeruleus. Its loss is directly connected to the loss of nerve cells in this part of the brain, which plays a role in Parkinson’s Disease. Magnetic resonance imaging (MRI) is an ideal tool to monitor the amount of NM in the brain in vivo. The aim of the study was the development of tools and methodology for the quantification of NM in a special neuromelanin-sensitive MRI images. The first approach was done by creating regions of interest, corresponding to the anatomical position of SN based on an anatomical atlas and determining signal intensity threshold. By linking the anatomical and signal intensity information, we were able to segment the SN. As a second approach, the neural network U-Net was used for the segmentation of SN. Subsequently, the volume characterizing the amount of NM in the SN region was calculated. To verify the method and the assumptions, data available from various patient groups were correlated. The main benefit of this approach is the observer-independency of quantification and facilitation of the image processing process and subsequent quantification compared to the manual approach. It is ideal for automatic processing many image sets in one batch.

scholarly journals Hemosiderosis of Central Nervous System: a case report of a rare and underdiagnosed disease

2021 ◽  
Vol 10 (11) ◽  
pp. e270101119579
Author(s):  
Cássio Marques Perlin ◽  
Lanusa Alquino Colombo ◽  
Anderson Dillmann Groto ◽  
Bruno Gleizer da Silva Rigon
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Superficial Siderosis ◽  
Medical Clinic ◽  
Resonance Imaging ◽  
System A ◽  
Magnetic Resonance Imaging Mri ◽  
Brain And Spinal Cord ◽  
The Brain

Superficial Siderosis (SS) of Central Nervous System is a rare disease characterized by the deposit of hemosiderin in the brain and spinal cord. Clinically, it is characterized by progressive sensorineural ataxia and deafness associated with injury of superior motor neuron. The diagnosis is made by magnetic resonance imaging (MRI) of the encephalon and spinal cord. The objective of the study is to report the case of a patient with characteristic elements of the syndrome, accompanied in a private medical clinic.

scholarly journals Effects of Red Ginseng on Neural Injuries with Reference to the Molecular Mechanisms

J ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 116-127
Author(s):  
Pengxiang Zhu ◽  
Masahiro Sakanaka
Keyword(s):  
Molecular Mechanisms ◽  
Bioactive Molecules ◽  
Red Ginseng ◽  
Promising Candidate ◽  
Neuroprotective Effects ◽  
Chemical Structures ◽  
Brain And Spinal Cord ◽  
The Brain

Red ginseng, as an effective herbal medicine, has been traditionally and empirically used for the treatment of neuronal diseases. Many studies suggest that red ginseng and its ingredients protect the brain and spinal cord from neural injuries such as ischemia, trauma, and neurodegeneration. This review focuses on the molecular mechanisms underlying the neuroprotective effects of red ginseng and its ingredients. Ginsenoside Rb1 and other ginsenosides are regarded as the active ingredients of red ginseng; the anti-apoptotic, anti-inflammatory, and anti-oxidative actions of ginsenosides, together with a series of bioactive molecules relevant to the above actions, appear to account for the neuroprotective effects in vivo and/or in vitro. Moreover, in this review, the possibility is raised that more effective or stable neuroprotective derivatives based on the chemical structures of ginsenosides could be developed. Although further studies, including clinical trials, are necessary to confirm the pharmacological properties of red ginseng and its ingredients, red ginseng and its ingredients could be promising candidate drugs for the treatment of neural injuries.

Cat Brain Neuroanatomy using Cryosectioning, Magnetic Resonance and Computed Tomography Imaging Modalities

2020 ◽  
Keyword(s):  
Computed Tomography ◽  
Magnetic Resonance ◽  
Neurological Diseases ◽  
Gross Anatomy ◽  
Diagnosis And Treatment ◽  
Imaging Modalities ◽  
Brain Anatomy ◽  
The Common ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

Magnetic resonance imaging (MRI) and computed tomography (CT) imaging modalities are invaluable for the diagnosis and treatment of neurological diseases. This study aimed to correlate the anatomical sectional data of the cats’ brain to the sections obtained by both MRI and CT examination. The present work was conducted on four cats, 1-4 years old, weighing about (2.5 to 3.5) kg admitted to the hospital with terminal diseases not related to the nervous system. The anatomical sections were taken at intervals of 5 mm, on different planes such as sagittal, frontal and transverse. The sections were obtained, following humane euthanasia, from frozen heads and identified according to the previous literatures. The images from both MRI and CT were compared with those of the gross anatomy sections and different structures were identified. To identify arterial distribution in the brain, one cat was injected with red latex through the common carotid artery, frozen, and sectioned. For vascular imaging, the same cat was examined by MRI after intravenous injection of contrast media. The descriptions of the brain anatomy from the MRI and CT images will act as a basis for the diagnosis and treatment of different neurological diseases in cat. This will assist veterinarians and radiologists in the identification of various nervous lesions related to the brain.

Alzheimer's disease and Down's syndrome: an in vivo MRI study

2008 ◽  
Vol 39 (4) ◽  
pp. 675-684 ◽  
Author(s):  
F. Beacher ◽  
E. Daly ◽  
A. Simmons ◽  
V. Prasher ◽  
R. Morris ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Down's Syndrome ◽  
Down’S Syndrome ◽  
Brain Anatomy ◽  
Volumetric Mri ◽  
Regional Brain ◽  
Magnetic Resonance Imaging Mri ◽  
Mri Study

BackgroundIndividuals with Down's syndrome (DS) are at high risk of developing Alzheimer's disease (AD). However, few studies have investigated brain anatomy in DS individuals with AD.MethodWe compared whole brain anatomy, as measured by volumetric magnetic resonance imaging (MRI), in DS individuals with and without AD. We also investigated whether volumetric differences could reliably classify DS individuals according to AD status. We used volumetric MRI and manual tracing to examine regional brain anatomy in 19 DS adults with AD and 39 DS adults without AD.ResultsDS individuals with AD had significantly smaller corrected volumes bilaterally of the hippocampus and caudate, and right amygdala and putamen, and a significantly larger corrected volume of left peripheral cerebrospinal fluid (CSF), compared to DS individuals without AD. The volume of the hippocampus and caudate nucleus correctly categorized 92% and 92% respectively of DS individuals without AD, and 75% and 80% respectively of DS individuals with AD.ConclusionsDS individuals with AD have significant medial temporal and striatal volume reductions, and these may provide markers of clinical AD.

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